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Title: JTR releases new 2x18 Subwoofers - info here
Post by: Steve Litscher on August 06, 2018, 01:24:07 pm
Well, Jeff is at it again... (lucky for all of us)

We've been working with Jeff at JTR to get a direct radiating, dual 18" subwoofer that would hit hard, play low, and remain "musical" and "controlled" without being too woofy or sloppy. Those who are familiar with Jeff's home theater stuff know that he can get subs to do some crazy things... 10.5Hz at +/- 3dB, for example.

His Orbit Shifters are awesome in their own right, and the new C212Pro subs are absolute maniacs... a 70-lb sub that goes to 39Hz and puts out more bass than it has a right to (we have six of the C212Pros).

Anyway, to get to the good stuff, we debuted the first set of 2x18 HO subs over the weekend. We picked them up from Jeff on Friday - he didn't have the grilles ready, but we took them anyway. Grilles should be available this week.

The specs look excellent - 27Hz - 190Hz (+/- 3dB), 139dB within CEA2010 distortion, available as powered or passive units. We bought four of the powered units.

Deployed them at an outdoor venue - wide open space without any buildings or backdrops to help with gain. A pair easily covered 400-ish people; we measured 106-108dB c-weighted at the back of the venue's space (when pushing it a bit). The pair managed a very comfortable 102-103dB c-weighted just past FOH (about 70-feet back).

Jeff should have more info on these soon. I can't wait to deploy four of them at a larger event and see what they can do. The build quality is typical JTR - heavily overbuilt, and absolutely flawless in every regard. Lots of handles in the cabinets, and they tilt-back and roll for easy transport. They can be deployed horizontally or vertically. There are pole cup mounts for vertical orientation. I'd put the weight at around 175-pounds if I had to guess.

I only have one photo of them from the night. Ignore the caution tape... without grilles, it was a "quick fix" to attempt to keep people away from them. Thankfully, people were very respectful at the event and we didn't have any issues to contend with. We'll get some better photos at future events, and will provide additional updates.

I also attached a fairly poor photo of the venue; the band set-up in the top-left corner of the photo and people were spread out over the entire brick-paver area.

Title: Re: New JTR subwoofer - 2x18 HO
Post by: Patrick Cognitore on August 16, 2018, 01:26:18 pm
So this is a different model from the Captivator 218 Pro? Specs seem fairly close, but looking at pics of each the construction looks different. I'm curious why there are two models seemingly filling the same niche.

 
Well, Jeff is at it again... (lucky for all of us)

We've been working with Jeff at JTR to get a direct radiating, dual 18" subwoofer that would hit hard, play low, and remain "musical" and "controlled" without being too woofy or sloppy. Those who are familiar with Jeff's home theater stuff know that he can get subs to do some crazy things... 10.5Hz at +/- 3dB, for example.

His Orbit Shifters are awesome in their own right, and the new C212Pro subs are absolute maniacs... a 70-lb sub that goes to 39Hz and puts out more bass than it has a right to (we have six of the C212Pros).

Anyway, to get to the good stuff, we debuted the first set of 2x18 HO subs over the weekend. We picked them up from Jeff on Friday - he didn't have the grilles ready, but we took them anyway. Grilles should be available this week.

The specs look excellent - 27Hz - 190Hz (+/- 3dB), 139dB within CEA2010 distortion, available as powered or passive units. We bought four of the powered units.

Deployed them at an outdoor venue - wide open space without any buildings or backdrops to help with gain. A pair easily covered 400-ish people; we measured 106-108dB c-weighted at the back of the venue's space (when pushing it a bit). The pair managed a very comfortable 102-103dB c-weighted just past FOH (about 70-feet back).

Jeff should have more info on these soon. I can't wait to deploy four of them at a larger event and see what they can do. The build quality is typical JTR - heavily overbuilt, and absolutely flawless in every regard. Lots of handles in the cabinets, and they tilt-back and roll for easy transport. They can be deployed horizontally or vertically. There are pole cup mounts for vertical orientation. I'd put the weight at around 175-pounds if I had to guess.

I only have one photo of them from the night. Ignore the caution tape... without grilles, it was a "quick fix" to attempt to keep people away from them. Thankfully, people were very respectful at the event and we didn't have any issues to contend with. We'll get some better photos at future events, and will provide additional updates.

I also attached a fairly poor photo of the venue; the band set-up in the top-left corner of the photo and people were spread out over the entire brick-paver area.
Title: Re: New JTR subwoofer - 2x18 HO
Post by: John Schalk on August 16, 2018, 01:59:29 pm
More pictures please.  Side, back, etc.  Jeff hasn't announced these on the JTR Facebook page yet so we must depend on Steve for more details!
Title: Re: New JTR subwoofer - 2x18 HO
Post by: Steve Litscher on August 17, 2018, 10:57:42 am
More pictures please.  Side, back, etc.  Jeff hasn't announced these on the JTR Facebook page yet so we must depend on Steve for more details!

Official word from Jeff:

- The name for the new 2x18 high output (our project name was "218HO") subwoofers is "Captivator 218 Pro"

- The website has accurate/current specifications

- The website doesn't have photos of the new design

- This design replaces the previous model; it doesn't go as low as the previous model (the old ones were tuned to 19Hz), but it has more output overall than the previous model

- The drivers are all new

- New amplifiers; available as passive or active


I've had a chance to use these for three shows now. I'm liking them quite a bit. They definitely have a much fuller sound, and are very clean and hard hitting. Two of them are all that we've rolled out so far (we have four), and they've been more than enough for our outdoor gigs.

Gig #1 was highlighted in the post above.

Gig #2 was under a really small "beer tent" at a small local festival. Set-up on the ground... No stage... (oye) Low tent... no backdrop... I got a few photos of the subs at the event - the photos show the subs with their grilles as well as the amplifier.

The amplifier is a SpeakerPower unit - Jeff works closely with them. The drivers are 4-ohms each, so if you purchase the passive model, you'll have to choose between 8-ohm load or 2-ohm load. If my memory serves correctly, Jeff wants about 800-watts continuous per driver, so a PL380 in stereo should be about perfect. Check with Jeff to confirm, though.

The active models work really well - they have the usual controls on the back (gain, LF adjust, crossover, delay), along with a single XLR (no pass through) and a set of RCA (assumedly for HT use). There's a master on/off switch as well as a "on/off" switch. There's also a Speak-On output jack... more to come on that. Power is supplied by IEC. I believe they pull around 8A at 1/8 power, but that may be a bit on the high side.

Gig #3 was for a "national night out" at a large park. Again, no cover, no stage (ugh), no backdrop to get some free gain from. Had about 800-ish people at the park and had no issue running the two C218 Pros. Used DSR112 on top (the performance area was raised via a natural slope). I pushed the DSR112 pretty hard; was told it was going to be much smaller venue and crowd... but everything worked well. If I had my way, I would've paired the C218Pro with 3TX or our TTL-6As for this event.

No gigs this weekend, but I will likely be doing some work in the storage unit, so I'll try to get a few more/better photos of the subs.

They measure just about the same as an Orbit Shifter, but are slightly shorter and ever so slightly deeper. The handles make for easy maneuvering - There are the "Orbit Shifter-like" handles on the top back edge, two sets of hand holds on the top (along with pole mount cup), and another hand hold on the bottom, on the same plane as the tilt-back casters.

Hope this info helps. Feel free to contact Jeff with any other questions!
Title: Re: New JTR subwoofer - 2x18 HO
Post by: Steve Litscher on August 17, 2018, 11:00:10 am

Gig #3 was for a "national night out" --- (attaching photo of the event/set-up)

Hope this info helps. Feel free to contact Jeff with any other questions!
Title: Re: New JTR subwoofer - 2x18 HO
Post by: John Schalk on August 17, 2018, 01:29:39 pm
Thanks for the additional info and pictures Steve.  These look really promising to me as they line up pretty well with my existing power amp options.  I'm still probably not a buyer until next spring, but nice to know that Jeff is updating his products for live sound.
Title: Re: New JTR subwoofer - 2x18 HO
Post by: Steve Garris on August 17, 2018, 03:09:31 pm
Very cool - I love the active design. Just curious, why would someone want these over the Orbit Shifters?
Title: Re: New JTR subwoofer - 2x18 HO
Post by: Lance Hallmark on August 17, 2018, 03:45:48 pm
Very cool - I love the active design. Just curious, why would someone want these over the Orbit Shifters?

They go about 10hz lower, where a lot of EDM is going these days.
I'd like to know how well a pair would play with a pair of Orbit Shifters
Title: Re: New JTR subwoofer - 2x18 HO
Post by: Patrick Cognitore on August 17, 2018, 08:43:56 pm
Thanks for the update Steve, that all makes sense. I recalled the other specs for the Captivator 218 pro and noticed they had changed. 27hz is great low extension, and the output looks tremendous.

I'm curious about the built in limiting on the amp. Is there any, how sophisticated, etc.
Title: Re: New JTR subwoofer - 2x18 HO
Post by: Ivan Beaver on August 18, 2018, 12:21:03 pm
They go about 10hz lower, where a lot of EDM is going these days.
I'd like to know how well a pair would play with a pair of Orbit Shifters
The following is a general statement, and is not inferring or referencing any of the products in discussion, It is for general information and consideration.

The useful output of any loudspeaker is a combination of extension and sensitivity and power handling.

A simple number ( goes 10Hz lower) doesn't tell anything about how loud it is at that freq.

The -3dB or -10dB etc MUST be referenced to SOMETHING or else it has NO meaning.  It should be referenced to the sensitivity to have any valid meaning.

But sadly, there are plenty of examples of top manufactures whos own graphs and simple number spec sheets are VERY wrong.  I have some that are more than 20dB off.  that is only a factor of 100.  What if your pay check was off by 2 zeros?  I bet you would care THEN.  HA HA

ANY loudspeaker EVER made, including soft dome tweeters, can EASILY reproduce 1Hz.  So every loudspeaker goes down to 1 Hz.

Now how LOUD they are at 1 Hz is a TOTALLY different story.

You MUST know more information than a simple number.

Simple numbers will get you trouble every time.
Title: JTR releases new 2x18 Subwoofers - info here
Post by: Steve Litscher on August 19, 2018, 12:58:33 pm
Answering a couple of questions from above:

- I like the direct radiating design over the OS. The OS is amazing with what it can achieve from a single 18Ē driver, and it sounds darned good. But the extra delay and some node cancelation challenges in certain environments and configs had me wanting to go direct radiating. Granted, direct radiating isnít a magic wand, but itís a little less fussy in specific situations.

- The amps have full DSP, including limiting. Jeff programs them and thoroughly tests them prior to shipping. SpeakerPower has pretty decent processing in their active units - weíve been using the C212Pro for about a year; they have the SpeakerPower amps with DSP as well - no complaints.

- Output at 27Hz; I rarely run anything below around 35-36Hz, but knowing Jeff, if he says 27Hz, I trust that the speaker has usable output at that frequency. If Jeff does anything, itís over deliver and under promise. :-) Iím not a gambling man, but my bet would be that 27Hz is +/- 3dB. Jeff would know for sure.


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Title: Re: New JTR subwoofer - 2x18 HO
Post by: Lance Hallmark on August 20, 2018, 03:34:04 pm
The following is a general statement, and is not inferring or referencing any of the products in discussion, It is for general information and consideration.

The useful output of any loudspeaker is a combination of extension and sensitivity and power handling.

A simple number ( goes 10Hz lower) doesn't tell anything about how loud it is at that freq.

The -3dB or -10dB etc MUST be referenced to SOMETHING or else it has NO meaning.  It should be referenced to the sensitivity to have any valid meaning.

But sadly, there are plenty of examples of top manufactures whos own graphs and simple number spec sheets are VERY wrong.  I have some that are more than 20dB off.  that is only a factor of 100.  What if your pay check was off by 2 zeros?  I bet you would care THEN.  HA HA

ANY loudspeaker EVER made, including soft dome tweeters, can EASILY reproduce 1Hz.  So every loudspeaker goes down to 1 Hz.

Now how LOUD they are at 1 Hz is a TOTALLY different story.

You MUST know more information than a simple number.

Simple numbers will get you trouble every time.

My bad, it is listed on the web site

Frequency +/- 3db
27-190hz (tuned to 27hz), active version
Sensitivity (half space)
103db, 1 watt, 1.41 volt, 2 ohm (half space)
Usable Output
138db (Calculated peak 141db Ė 3db compression)

I sometimes put an answer out quickly without attention to detail - too much time on about every other dumbed down social media site & forum. It is that attention to detail and how important those details are for true knowledge and understanding that I love about this forum, I apologize for lowering the bar sometimes which is why I am here mostly to learn.
Title: Re: New JTR subwoofer - 2x18 HO
Post by: John Schalk on August 20, 2018, 04:56:47 pm

Sensitivity (half space)
103db, 1 watt, 1.41 volt, 2 ohm (half space)

I am considering driving each speaker separately so how do I translate the single 2 ohm sensitivity spec into two 4 ohm loads?  I understand 2.83 for 8 ohms, 2.00 for 4 ohms, and now 1.41 for 2 ohms but I'm lost when it comes to going from a single load to dual loads.
Title: Re: New JTR subwoofer - 2x18 HO
Post by: Art Welter on August 20, 2018, 08:02:04 pm
I am considering driving each speaker separately so how do I translate the single 2 ohm sensitivity spec into two 4 ohm loads?  I understand 2.83 for 8 ohms, 2.00 for 4 ohms, and now 1.41 for 2 ohms but I'm lost when it comes to going from a single load to dual loads.
Increasing from one to two "loads"  (driver/enclosure) increases sensitivity by 3dB.

Two drivers/enclosures each of 100 dB sensitivity would be equal to one dual driver/enclosure of 103 dB sensitivity. The one watt one meter sensitivity, (2.83V into 8 ohms, 2.00V at 4 ohms, 1.41V for 2 ohms) for the pair of drivers remains the same whether driven by one or two amplifiers.




Title: Re: New JTR subwoofer - 2x18 HO
Post by: John Schalk on August 20, 2018, 10:58:07 pm
Increasing from one to two "loads"  (driver/enclosure) increases sensitivity by 3dB.

Two drivers/enclosures each of 100 dB sensitivity would be equal to one dual driver/enclosure of 103 dB sensitivity. The one watt one meter sensitivity, (2.83V into 8 ohms, 2.00V at 4 ohms, 1.41V for 2 ohms) for the pair of drivers remains the same whether driven by one or two amplifiers.

Thanks for trying to help me Art, but I'm still not sure I understand.  I would like to know what the calculated output of this sub will be if I power it with two amp channels that produce 1250 watts @ 4 ohms.  Can I simply add the two channels together (2500 watts) and then use the supplied 103 dB sensitivity spec and do the math?  If so, I come up with an output of ~137 dB which is pretty close to Jeff's usable output spec of 138 dB.  Did I do that correctly?
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Art Welter on August 20, 2018, 11:24:38 pm
Yes, an output of ~137 dB would result at the frequencies that reach the 103 dB sensitivity specification with each 4 ohm driver powered with ~1250 watts, same as an amp capable of 5000 watts into two ohms for the pair.


Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Dan Mortensen on April 14, 2019, 02:26:59 am
I've looked with interest at the JTR powered stuff, and there are a few things I don't understand:

1) Why IEC and not Powercon?

2) Why an on/off switch that can get shut off by mistake?

3) Why are there knobs on it at all? All user adjustable processing for the gig should occur in the console or drive rack. IMO.

4) Any knob can get sheared off in transit.

5) Same for the little toggle switch "Auto" vs. something.

6) What provision is there for using them in the rain and having them continue to work?

I like the idea of lightweight subs (thinking of the 212 Captivator), but every one of those aspects is a deal-breaker for me.

Full disclosure: I think Meyer has all that right for powered speakers and I'm a dealer for them but use different subs for other reasons.

Edit: After writing this, I found another thread about Captivator 218's (I think) where people talked about the reasons why the amps are this way. While that was interesting, it doesn't change the fact that they are this way and therefore difficult to want to use.

FWIW I feel the same way about the amps in Behringer self-powered speakers and am a dealer for them, too, but live mostly in their mixer world. Haven't sold any speakers...
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ron Ventour on April 28, 2019, 07:51:41 am
I've looked with interest at the JTR powered stuff, and there are a few things I don't understand:

1) Why IEC and not Powercon?

2) Why an on/off switch that can get shut off by mistake?

3) Why are there knobs on it at all? All user adjustable processing for the gig should occur in the console or drive rack. IMO.

4) Any knob can get sheared off in transit.

5) Same for the little toggle switch "Auto" vs. something.

6) What provision is there for using them in the rain and having them continue to work?

I like the idea of lightweight subs (thinking of the 212 Captivator), but every one of those aspects is a deal-breaker for me.

Full disclosure: I think Meyer has all that right for powered speakers and I'm a dealer for them but use different subs for other reasons.

Edit: After writing this, I found another thread about Captivator 218's (I think) where people talked about the reasons why the amps are this way. While that was interesting, it doesn't change the fact that they are this way and therefore difficult to want to use.

FWIW I feel the same way about the amps in Behringer self-powered speakers and am a dealer for them, too, but live mostly in their mixer world. Haven't sold any speakers...

Got a link for that other cap 218 thread?
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Steve Litscher on April 29, 2019, 11:04:53 am
I've looked with interest at the JTR powered stuff, and there are a few things I don't understand:

1) Why IEC and not Powercon?

2) Why an on/off switch that can get shut off by mistake?

3) Why are there knobs on it at all? All user adjustable processing for the gig should occur in the console or drive rack. IMO.

4) Any knob can get sheared off in transit.

5) Same for the little toggle switch "Auto" vs. something.

6) What provision is there for using them in the rain and having them continue to work?

I like the idea of lightweight subs (thinking of the 212 Captivator), but every one of those aspects is a deal-breaker for me.



All of these questions can be distilled down to a single answer: economy of scale.

Jeff is a small, single-man operation and has to make decisions about where he can streamline production and save on costs. His amplifiers are made by SpeakerPower in California, and he had them cut/build a common amplifier plate for his product line.

He's huge in the Home Theater world, and I'm guessing the majority of his sales are HT-related. He's gaining traction in the Pro Sound world, but it's a long, arduous road. As such, when he spec'd his plates from SpeakerPower, he did so more for the HT world.

I've asked him a number of times for PowerCon, flat switches, and whatnot. He can do it, but it's extremely pricey, and he's sitting on a large inventory of amp plates that were already made-up in their current config.

Regarding rain... I've used his stuff in the rain without issue. As is the case with nearly any active speaker, a good set of rain covers or rain shields are critical.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Dan Mortensen on April 30, 2019, 04:00:42 pm
Got a link for that other cap 218 thread?

Nope, sorry, IIRC I did a search for the 218 and found a thread somewhere else, so you could find it, too?

But now the post below essentially says the same things that I thought I saw in that mysterious other thread.



All of these questions can be distilled down to a single answer: economy of scale.

Jeff is a small, single-man operation...


Regarding rain... I've used his stuff in the rain without issue. As is the case with nearly any active speaker, a good set of rain covers or rain shields are critical.

I deeply understand and appreciate the limits of being a one man operation. I have emailed Jeff and promptly received back complete and clear replies, and appreciated that, too. However, my points in the post you quoted still stand.

Regarding the rain covers, the covers I've seen have been nylon, and I presume the amp modules generate heat. Don't they melt nylon if in direct contact?

The rain shields I've seen are made of stiff plastic or metal and bolt on with ventilation, but I'm not in a mood these days to design and build something like that which would indeed protect the modules from weather and handling, but which would add depth to an already deep box (aren't the 212's 3' deep when in use? And the 218's as deep if not deeper? I confess that after making a decision not to look further into them, that info has exited my brain) if the shields were left on permanently, and if left off expose an amp module with protruding switches and knobs, or maybe one of each, to damage that I'd then have to design something to protect that situation.

These boxes seem like they'd be fine for unpowered use, but then in my specific case I'm replacing something I already have and like which works fine (old unpowered Bag End double 18's) with essentially the same thing, except I've spent $10,000+ to do so and get enough of them.

If I didn't already have a solution, these boxes do seem better in that they're lighter and newer technology.

YMMV, of course.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Mark Wilkinson on April 30, 2019, 05:30:36 pm
Dan, IMO, the powered 218 with ice-amps is home theatre...
Just go passive ...then concerns melt away...
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Steve Litscher on May 01, 2019, 11:01:44 am
Regarding the rain covers, the covers I've seen have been nylon, and I presume the amp modules generate heat. Don't they melt nylon if in direct contact?

The rain shields I've seen are made of stiff plastic or metal and bolt on with ventilation, but I'm not in a mood these days to design and build something like that which would indeed protect the modules from weather and handling, but which would add depth to an already deep box (aren't the 212's 3' deep when in use? And the 218's as deep if not deeper? I confess that after making a decision not to look further into them, that info has exited my brain) if the shields were left on permanently, and if left off expose an amp module with protruding switches and knobs, or maybe one of each, to damage that I'd then have to design something to protect that situation.

These boxes seem like they'd be fine for unpowered use, but then in my specific case I'm replacing something I already have and like which works fine (old unpowered Bag End double 18's) with essentially the same thing, except I've spent $10,000+ to do so and get enough of them.

If I didn't already have a solution, these boxes do seem better in that they're lighter and newer technology.

YMMV, of course.


Sounds like you've got a good solution that you're happy with.

Regarding the heat of the amplifiers... From what I've experienced, they get warm, but never so hot that you can't touch them, so I seriously doubt that anything would melt if it cam in contact with them. We've used UnderCover NYC covers with zero issues and zero degradation in performance.

The warmest I've ever seen the amplifiers get was on an early September day, full sun, 103-104F ambient... the amps were quite warm, but not so hot as to melt nylon or plastic or anything else. Two of our DSR112s shut themselves off because of the heat; the C218Pro kept pounding away.

Regarding depth/size, the C212Pro are 22" deep and the C218Pro are about 32" deep. The C218Pro are *serious* subs. I'd put them up against the 9006 all day long, and they'll still play lower than the 9007. I've mixed on all three, and I'd have zero concerns using the C218Pro in almost any situation.

The "protruding knobs" still sit flush with the back of the cabinet; no different than the 9006 and 9007 with their DSP controller knob. It's not like the amplifier plate is bolted to the back of the box; it's recessed into the cabinet, just like any other pro sub design.

The only real gripes, IMHO are the lack of PowerCon and the extra switches. In terms of power and reliability, I've had 3 RCF amplifier failures, zero with the JTR. SpeakerPower builds some pretty reliable and robust stuff.

I sound like a broken record, I'm sure... but Jeff has got some killer subs here. A little more tweaking, and they'd be game changers. Heck, they already are, as they cost 1/2 as much as the 9006 and will keep-up, if not out-run it, all day long.
 
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ron Ventour on May 05, 2019, 06:48:38 am
Does anyone have the passive version of the Cap 218 pro? would like to know how the input connections are set up in the back, is it one connection for both drivers or 2 separate connections for each drivers?

 Is there a through connector for another sub? How much power would you throw at this sub? I think someone mentioned the passive version come in 8 and 2 ohm loads only.

Do the Cap 218 have the same output or similar of a Orbit Shifter?

Sent from my SM-N950U using Tapatalk
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: drew gandy on May 07, 2019, 09:43:29 pm
So, does this mean the pendulum has swung back to vented boxes again?  Horns are out? 
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: John Schalk on May 08, 2019, 08:56:44 am
So, does this mean the pendulum has swung back to vented boxes again?  Horns are out?
From conversations that I have had with some forum members regarding the Orbit Shifter specifically, some owners have had trouble getting it accepted on riders.  I can't say that is why JTR came out with a double 18" sub in their Pro range, but....  I will add that David at Bassboss, formerly BassMax, builds primarily self-powered, vented boxes now, possible for the same reason.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Steve Litscher on May 08, 2019, 09:19:51 am
Does anyone have the passive version of the Cap 218 pro? would like to know how the input connections are set up in the back, is it one connection for both drivers or 2 separate connections for each drivers?

For the passive versions, there are two metal Neutrik NL4 connectors on the back and they can be wired as either:

a) Direct to each driver (no parallel) for a 4-ohm load per input
b) In parallel for a total load of 8-ohms load


Quote
How much power would you throw at this sub?

Jeff recommends 1200-watts RMS per driver. I'd probably look for something with more juice and then limit accordingly.


Quote
Do the Cap 218 have the same output or similar of a Orbit Shifter?

This is by no means a scientific measurement.... but, my experience has been that one C218 is equal to about 1.5 OS in terms of total output. Keep in mind, the C218 goes 12Hz lower than the OS, too. From 60Hz-80Hz, they're probably very similar in output per box.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ron Ventour on May 08, 2019, 09:54:10 am
For the passive versions, there are two metal Neutrik NL4 connectors on the back and they can be wired as either:

a) Direct to each driver (no parallel) for a 4-ohm load per input
b) In parallel for a total load of 8-ohms load


Jeff recommends 1200-watts RMS per driver. I'd probably look for something with more juice and then limit accordingly.


This is by no means a scientific measurement.... but, my experience has been that one C218 is equal to about 1.5 OS in terms of total output. Keep in mind, the C218 goes 12Hz lower than the OS, too. From 60Hz-80Hz, they're probably very similar in output per box.
Thanks Steve, but in parallel wouldn't it be 2-ohms since the drivers are 4-ohms each?

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Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Steve Litscher on May 08, 2019, 10:50:41 am
Thanks Steve, but in parallel wouldn't it be 2-ohms since the drivers are 4-ohms each?

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I talked directly with Jeff this morning to confirm, and thatís what he said. 8-ohms with parallel connection.

Iím guessing he could do 2-ohm as well.




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Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ron Ventour on May 08, 2019, 11:08:45 am
I talked directly with Jeff this morning to confirm, and thatís what he said. 8-ohms with parallel connection.

Iím guessing he could do 2-ohm as well.




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Ok, so @8-ohms parallel, you can throw 2500w at it?

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Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Mac Kerr on May 08, 2019, 11:18:22 am
I talked directly with Jeff this morning to confirm, and thatís what he said. 8-ohms with parallel connection.

Iím guessing he could do 2-ohm as well.

I'm guessing that's series not parallel. With 4Ω drivers, 2 in series is 8Ω, 2 in parallel is 2Ω.

Mac
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Steve Litscher on May 08, 2019, 01:07:08 pm
I'm guessing that's series not parallel. With 4Ω drivers, 2 in series is 8Ω, 2 in parallel is 2Ω.

Mac

Sorry; I'm using bad terminology... I believe what he meant is that if he offers a parallel connector on the back, the drivers are wired in series for 8-ohms internally. So, two cabinets would present a 4-ohm load. And yes, with 8-ohm load, 2500-watts would put you in the sweet spot.

The best bet would be to contact Jeff directly.

He's slammed at the moment as a result of the AXPONA show a few weeks ago, so give him a bit to respond.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Roland Clarke on May 08, 2019, 02:13:26 pm
From conversations that I have had with some forum members regarding the Orbit Shifter specifically, some owners have had trouble getting it accepted on riders.  I can't say that is why JTR came out with a double 18" sub in their Pro range, but....  I will add that David at Bassboss, formerly BassMax, builds primarily self-powered, vented boxes now, possible for the same reason.

This really surprises me.  If you are at the level where you are supplying JTR, Iím surprised that rider acceptance is even a consideration.  Perhaps itís the suppliers own expectation bias that their clients are not going to accept what they supply.  Iíve had customers sometimes ask if I was going to supply perhaps D&B or LíAcoustic, etc, etc, but Iíve never had a customer turn down what Iíve offered to supply if I told them it was suitable for their job.  We should perhaps, think more of ourselves as experts and consultants.  My job is to provide a customer with a sound solution that meets their needs and is suitable for the job.  We need innovative products to advance our industry not just plain run of the mill vanilla boxes.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Taylor Hall on May 08, 2019, 02:38:24 pm
This really surprises me.  If you are at the level where you are supplying JTR, Iím surprised that rider acceptance is even a consideration.  Perhaps itís the suppliers own expectation bias that their clients are not going to accept what they supply.  Iíve had customers sometimes ask if I was going to supply perhaps D&B or LíAcoustic, etc, etc, but Iíve never had a customer turn down what Iíve offered to supply if I told them it was suitable for their job.  We should perhaps, think more of ourselves as experts and consultants.  My job is to provide a customer with a sound solution that meets their needs and is suitable for the job.  We need innovative products to advance our industry not just plain run of the mill vanilla boxes.
Unfortunately, innovation rarely trumps preconceived notions when it doesn't have a big name painted on it...
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Mark Wilkinson on May 08, 2019, 05:17:18 pm
From conversations that I have had with some forum members regarding the Orbit Shifter specifically, some owners have had trouble getting it accepted on riders.  I can't say that is why JTR came out with a double 18" sub in their Pro range, but....  I will add that David at Bassboss, formerly BassMax, builds primarily self-powered, vented boxes now, possible for the same reason.

I dunno John, I'm kinda doubting the double 18"production is about riders.

My bet is that folks just want to dig ever lower in frequency.
And that ported 18"s are an easier way to get down there compared to horns.
A horn has to be real big, or has to be able to be coupled together with more boxes and go lower when coupled, to match the bass reflexes
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Caleb Dueck on May 08, 2019, 09:44:03 pm
I dunno John, I'm kinda doubting the double 18"production is about riders.

My bet is that folks just want to dig ever lower in frequency.
And that ported 18"s are an easier way to get down there compared to horns.
A horn has to be real big, or has to be able to be coupled together with more boxes and go lower when coupled, to match the bass reflexes

The article on the BassBoss site (David Lee) indicates ported is due to physical size, not sound accuracy, when it comes to the lowest octave vs horn loaded subwoofers.  There was an article or email from them about ported for the deepest bass and horns for the rest for time domain accuracy.

If Danley could get the same performance down deep from a ported sub vs huge horns (BC418), wouldn't they?   

From my listening experiences, I haven't heard ported sound as accurate as a good horn. 
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Tim McCulloch on May 08, 2019, 10:58:28 pm
The article on the BassBoss site (David Lee) indicates ported is due to physical size, not sound accuracy, when it comes to the lowest octave vs horn loaded subwoofers.  There was an article or email from them about ported for the deepest bass and horns for the rest for time domain accuracy.

If Danley could get the same performance down deep from a ported sub vs huge horns (BC418), wouldn't they?   

From my listening experiences, I haven't heard ported sound as accurate as a good horn.

Most folks (including a bunch of LABsters) have no idea what clean & accurate bass (up to about 100 Hz) sounds like.  They're accustomed to coloration and distortion, esp 2nd and 3rd harmonics.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Chris Grimshaw on May 09, 2019, 03:47:51 am
If you stay -6dB from the limiters (ie, you've brought twice as many subs as needed) you're still using half of the available cone excursion. I'd expect significant distortion percentages from the drivers even if it's in their so-called linear region.

Let's not forget - we're waving bits of cardboard around with magnets.


Chris
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Roland Clarke on May 09, 2019, 04:25:28 am
Iím a long term lover of 1/4 wave stuff, lack of distortion and the weight you can get, none of the chuff that ported systems mostly suffer from.  You can get low bass from alternative systems without getting large, but itís the same old syndrome.  Small size, SPL, Low frequency,  pick two.  Even reflex cabs arenít immune to this.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Roland Clarke on May 09, 2019, 05:52:31 am
The article on the BassBoss site (David Lee) indicates ported is due to physical size, not sound accuracy, when it comes to the lowest octave vs horn loaded subwoofers.  There was an article or email from them about ported for the deepest bass and horns for the rest for time domain accuracy.

If Danley could get the same performance down deep from a ported sub vs huge horns (BC418), wouldn't they?   

From my listening experiences, I haven't heard ported sound as accurate as a good horn.

I think we donít we are necessarily making the correct distinctions.  Bass ďhornsĒ are for all intents and purposes a fallacy as regards what we use in pro audio.  True horns need extreme mouth areas to reproduce very low frequency, hence why horns stacked in multiples do improve extension.  The reality of all practical horns we use are that they are deriving their bass from the horn length, effectively making them a 1/4 wave design.  Tapped horns, scoops, rear loaded, front loaded are all only variants of the same physical phenomena.  True bass horns, as I understand, require a reasonably gentle expansion rate, therefore they would exhibit significant delay rendering them of no practical use for live systems.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ivan Beaver on May 09, 2019, 08:17:11 am
I think we donít we are necessarily making the correct distinctions.  Bass ďhornsĒ are for all intents and purposes a fallacy as regards what we use in pro audio.  True horns need extreme mouth areas to reproduce very low frequency, hence why horns stacked in multiples do improve extension.  The reality of all practical horns we use are that they are deriving their bass from the horn length, effectively making them a 1/4 wave design.  Tapped horns, scoops, rear loaded, front loaded are all only variants of the same physical phenomena.  True bass horns, as I understand, require a reasonably gentle expansion rate, therefore they would exhibit significant delay rendering them of no practical use for live systems.
Multiple bass horns do not provide as much "extension" as people would like to think that they do.

The short horns (the ones used in PA applications) are made that size to enable a practical size.

This can cause ripples in the response down on the bottom, because the horn is not providing enough loading to the driver.

What really happens when you use multiples is that that the larger mouth starts to fill in the ripples.  So the overall "low end response" may appear louder (because it is smoother), but it really doesn't get much lower.

YES, the lower freq will be louder, but so will the rest of the response (due to the additional cabinets), but the actual -3dB point will not change much.

Remember that -3dB has NOT actual SPL value.  It is only a RELATIVE level that MUST be associated with some OTHER freq and level.

Without that reference, it could be anything.

So while ported cabinets may "appear" to go lower (the -3dB point may be lower), they may or may not be quieter at those freq than a horn cabinet that has a higher -3dB point.

It is a combination of the sensitivity, the freq response, the impedance and the power capacity that gives the REAL answer, NOT a simple number.

You MUST look at several factors, NOT just a simple single number to get an idea of how loud a particular cabinet will be at a specific freq.

A simple answer to a complex question often results in a wrong answer.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Caleb Dueck on May 09, 2019, 08:43:16 am
I think we donít we are necessarily making the correct distinctions.  Bass ďhornsĒ are for all intents and purposes a fallacy as regards what we use in pro audio.  True horns need extreme mouth areas to reproduce very low frequency, hence why horns stacked in multiples do improve extension.  The reality of all practical horns we use are that they are deriving their bass from the horn length, effectively making them a 1/4 wave design.  Tapped horns, scoops, rear loaded, front loaded are all only variants of the same physical phenomena.  True bass horns, as I understand, require a reasonably gentle expansion rate, therefore they would exhibit significant delay rendering them of no practical use for live systems.

True, "horn" is not a universal, defined term.  I was thinking specifically of the Danley DBH218 used in multiples, vs various other brands of ported subs. 

I prefer the sound of a sealed rear chamber front horn 😉 vs a tapped horn (TH118 in this case).  I'm biased slightly toward horns like the DBH218 vs tapped, but would need other non-tapped models to hear and compare.  IE a dual 15" folded horn to compare with TH115 and BC415, and ported like the TS215, and a folded 4x12 folded horn to compare with TH412 and BC414. 

Even if that were possible, it then highlights other differences.  IE, -3 cutoff frequency and how that changes the perceived tonal differences, and things like volume vs EQ on ported to make them sound "tighter" or more "sloppy". 

Ivan has a good point.  If we need X dB at 20Hz, and we are willing to EQ down the upper frequencies - we can calculate quantity and cubic volume of various sub models.  If I were sitting around bored I'd compare a few for fun.  Not counting power compression, and 4, or 5, or is it 6 dB SPL increase in the real world when doubling subs? 😉
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Roland Clarke on May 09, 2019, 10:03:02 am
Obviously Ivanís point is totally correct, but in practical terms we are almost always looking at being able to get, within reason, as much spl in the 50-100 hz range.  In this respect, Danley and any other manufacturer are not so different when looking at live sound reinforcement.  It also has to be born in mind that with the exception of outdoor use, many bass speakers are going to be compromised in the small and medium spaces that a lot of music concerts happen in.  The BC series speakers Danley make look interesting in that they use 1/4 wave design to produce insane spl.  Sure they are large, but Iíve seen videos of gigs with thousands of people at where the bass end was being handled by just 2 cabs.

I canít comment on the TH 118 as Iíve never heard one in the flesh, however, I have a couple of tapped horns I built which are based on the xoc 1 th18 design, but with some modifications and these are v good.  There are some double 18Ē I personally quite like, the KS28, J sub, HP700, etc.  I should also make the point that there are also a whole lot of terrible designs out there, trying to be different, but just flying in the face of all the physics we know.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Mark Wilkinson on May 09, 2019, 11:08:01 am
Multiple bass horns do not provide as much "extension" as people would like to think that they do.

The short horns (the ones used in PA applications) are made that size to enable a practical size.

This can cause ripples in the response down on the bottom, because the horn is not providing enough loading to the driver.

What really happens when you use multiples is that that the larger mouth starts to fill in the ripples.  So the overall "low end response" may appear louder (because it is smoother), but it really doesn't get much lower.

YES, the lower freq will be louder, but so will the rest of the response (due to the additional cabinets), but the actual -3dB point will not change much.


I see what you're saying. 
I think I've been one of those who's sometimes let the less rippled, smoother response of multiple labhorns vs a single, turn in to the illusion of a deeper low corner.
But in my defense lol, it is pretty commonly accepted that low end extension occurs with multiple front loaded horns...I mean even your DBH218 main page says so..

I've read that the horn's high pass frequency lowers as horn length increases and with a shallower flare rare.
Is that correct ?, and do those become the the main reasons that putting more boxes together doesn't lower the corner so much ? ?
 
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Roland Clarke on May 09, 2019, 11:36:54 am
I think that itís exactly that.  However, as the length increases you are effectively changing the 1/4 wave length which is what lowers the running.  My understanding is that to exhibit genuine horn characteristics the mouth of the horn would have to several metres wide and as the flare rate has to be gradual, many meters long, I suspect delay would be in terms of 30ms plus.  I think the directional nature of some of the Danley subs is particularly interesting when we are all having that discussion about directionality.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ivan Beaver on May 09, 2019, 12:14:35 pm
I think that itís exactly that.  However, as the length increases you are effectively changing the 1/4 wave length which is what lowers the running.  My understanding is that to exhibit genuine horn characteristics the mouth of the horn would have to several metres wide and as the flare rate has to be gradual, many meters long, I suspect delay would be in terms of 30ms plus.  I think the directional nature of some of the Danley subs is particularly interesting when we are all having that discussion about directionality.
Multiple cabinets will not change the length of the horn.  It is the length of the horn that is the biggest determining factor of the low freq extension.

Long horns=lower freq.  Yes there are other factors as well.

What does change with multiple cabinets is the impedance or radiation resistance that occurs where the cabinet mouth meets the air.

This impedance will affect the overall freq response.

Most PA horns are made to short, in order to make them transportable, so there is not as smooth a transition to the air as we would like.  Multiple cabinets help this transition.

It is all a matter of compromise
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Chris Grimshaw on May 09, 2019, 02:29:30 pm
Multiple cabinets will not change the length of the horn.  It is the length of the horn that is the biggest determining factor of the low freq extension.

Ivan,

A large stack of horns will have a longer effective path length:

Consider a large stack of horn loaded subs. Those at the bottom of the stack will effectively have their output constrained by the cabinets around them.
You could imagine positioning some plywood such that the sum of the applied pressure would be zero, and the plywood wouldn't vibrate in sympathy with the bass.
That bit of plywood would represent the extended horn path that's a result of the stack of horns.

Simulating stacks of front-loaded horns compared to single cabinets also shows a decrease in the lower cutoff.

Chris
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ivan Beaver on May 09, 2019, 02:54:33 pm
Ivan,

A large stack of horns will have a longer effective path length:

Consider a large stack of horn loaded subs. Those at the bottom of the stack will effectively have their output constrained by the cabinets around them.
You could imagine positioning some plywood such that the sum of the applied pressure would be zero, and the plywood wouldn't vibrate in sympathy with the bass.
That bit of plywood would represent the extended horn path that's a result of the stack of horns.

Simulating stacks of front-loaded horns compared to single cabinets also shows a decrease in the lower cutoff.

Chris
When people say "a lower cutoff", it really depends on how much?

I have measured a couple of stacks of different brands of horn subs, a couple of Hz is the most I have seen.

I would not get excited about a couple of Hz, untill you get below 20Hz or so.

Is the difference between 38 and 36Hz really enough to talk about?  38 and 30 yes.  36, not so much.

It is all a matter of magnitude.

I can go pee in the local lake and the lake level will rise.  Not enough to matter to anybody, but it DID rise.   Technically.

It comes down to "how much".  Just like saying that a 1200 watt amp has more headroom than a 1000 watt amp.  Technically that is true, but does it really matter and can anybody tell a difference?

Just sayin'------------
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Roland Clarke on May 09, 2019, 03:39:08 pm
Multiple cabinets will not change the length of the horn.  It is the length of the horn that is the biggest determining factor of the low freq extension.

Long horns=lower freq.  Yes there are other factors as well.

What does change with multiple cabinets is the impedance or radiation resistance that occurs where the cabinet mouth meets the air.

This impedance will affect the overall freq response.

Most PA horns are made to short, in order to make them transportable, so there is not as smooth a transition to the air as we would like.  Multiple cabinets help this transition.

It is all a matter of compromise

Iím totally agree with you, but the point I was making that at those frequencies apart from some gain, they arenít exhibiting any true horn characteristics because they would need to be much longer with a much larger exit.  What they are exhibiting is 1/4 wave behaviour.  This point was discussed with Martin King, who expressed the view that most of these cabinets, tapped horns and all are effectively transmission lines.  Iím inclined to agree with this interpretation.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Chris Grimshaw on May 09, 2019, 05:25:13 pm
The nomenclature around subwoofer cabinets can get very confusing. The tapped horn cabinets work as quarter-wave resonators for the bottom tuning frequency (I guess that's where the "transmission line" would come in), but there are other effects higher up.


Ivan, I see your point about small changes not being worth bothering about. I do, however, believe that the effective path length of a front-loaded horn will increase in large stacks, and the low corner will decrease in frequency. The simulations I have done back me up. Here's what I think is going on:

- When a single cabinet is used, the radiation becomes spherical in shape shortly after exiting the mouth of the horn.
- When we stack a load of subwoofer cabinets (assuming a square stack), we effectively create a plane source with dimensions of the order of metres, maybe 10s of metres.
- At some distance away from the stack, the wavefront tends towards spherical again*. I suspect that extra distance is the additional path length which appears to lower the LF cutoff.

FWIW, my simulations show dramatic changes in the low corner when 16x cabinets are used - from 52Hz to 34Hz.

* This would go some way to explaining the observation that large horn subwoofer stacks "throw" the sound a long way, with lower-than-expected levels near the stacks.

Chris
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ivan Beaver on May 09, 2019, 06:45:50 pm
  This point was discussed with Martin King, who expressed the view that most of these cabinets, tapped horns and all are effectively transmission lines.  Iím inclined to agree with this interpretation.
The first 2 versions of the Tapped horn were just basically "tapped transmission lines"

The transmission line turned into a horn after that, and he started to pickup more gain.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ivan Beaver on May 09, 2019, 06:49:34 pm


FWIW, my simulations show dramatic changes in the low corner when 16x cabinets are used - from 52Hz to 34Hz.

* This would go some way to explaining the observation that large horn subwoofer stacks "throw" the sound a long way, with lower-than-expected levels near the stacks.

Chris

I will admit I have never stacked up that many horns to see what happens, 4 is the most I have done, but I did not see any trend at that point.

Part of the reason the horn levels up close are not as loud as expected (but are correct in the far field) is due to the fact that the acoustic center is not at the front of the cabinet, but rather a distance behind.

So a bit of expansion has happened (inverse square law kinda) before the sound gets out of the cabinet.

That is another reason subs (expecially large ones) should be measured at a far distance.  I like 10M, because it is a 20dB  loss, so you just drive the signal 20dB harder (a voltage factor of 10) and the math becomes real easy :)
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Art Welter on May 09, 2019, 11:14:48 pm
Not counting power compression, and 4, or 5, or is it 6 dB SPL increase in the real world when doubling subs? 😉
Caleb,

In the real world doubling subs and power will result in a +6dB increase in low frequency output, plus additional gain due to the larger frontal area reducing rearward radiation. That said, as the center to center distances in the larger array become more than a 1/4 wavelength apart, they will have more upper band off axis reduction due to comb filtering, so will be less than +6.

This also furthers the "horns go way lower in multiples" myth, because the reduction in upper response makes it appear there is relatively more lower response.

Art
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Roland Clarke on May 10, 2019, 05:51:29 am
My take on this Art is that the increase in frontal area helps extend baffle step, but multiple cabs even putting out the exact same sound are very much not a single horn of the correct length with a mouth area large enough to lower the horn cut off response to 20-30hz.  When you look around, there are a whole bunch of front loaded horns with lower response -3db points of 38-40 hz and they are all of a reasonably generic size.  Itís perhaps understandable that to produce anything that breaks out of this mold requires a different design (tapped horn, bandpass, etc) or has to be much larger, I think that Danley have demonstrated this.

Much like the fact most double 18ís are of a fairly generic size, performance is going to be reasonably within similar bounds give or take driver quality and parameters, and port geometry.
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Caleb Dueck on May 10, 2019, 10:42:08 am
Caleb,

In the real world doubling subs and power will result in a +6dB increase in low frequency output, plus additional gain due to the larger frontal area reducing rearward radiation. That said, as the center to center distances in the larger array become more than a 1/4 wavelength apart, they will have more upper band off axis reduction due to comb filtering, so will be less than +6.

This also furthers the "horns go way lower in multiples" myth, because the reduction in upper response makes it appear there is relatively more lower response.

Art

6dB is the theoretical number, yes.  I mentioned this based on an old post Ivan did about a test he did where he found 5dB-ish was more the real world average sum. 
Title: Re: JTR releases new 2x18 Subwoofers - info here
Post by: Ivan Beaver on May 10, 2019, 11:01:11 am
6dB is the theoretical number, yes.  I mentioned this based on an old post Ivan did about a test he did where he found 5dB-ish was more the real world average sum.
There are different factors that will affect any measurement.

Things such as actual physical position of the mic vs the cabinets (remember that they are not in the same physical location-which would result in the +6dB), or a single mic placement vs mic placements over the intended coverage area etc.

How close you are to the sources (again mic placement), freq of interest (you may not get +6 depending on the mic placement vs freq), sometimes the actual placement of the cabinets (depending on the position of the woofers vs port area and how they are coupled to the other cabinets and at what freq) and so forth.