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Title: Rcf 8006 and 9006
Post by: Mike Santarelli on May 11, 2018, 09:16:13 am
Anyone hear these and can offer opinions? 

From what I have found the 9006 is a cleaner sounding sub with the 8006 having more punch in certain frequencies.

Looking for opinions between the two.
Title: Re: Rcf 8006 and 9006
Post by: Mike Santarelli on June 19, 2018, 10:26:09 am
Figured I follow up for anyone seeking the same questions.

I went to RCF and had a demo of the subs and the hdl20 and hdl30. 

First off, both subs sound amazing.  One will easily put out what two of my srx828 will.

The 9006 was my favorite.  It had incredible punch and the clarity was some of the best I've heard in a sub.  I was very impressed.
Title: Re: Rcf 8006 and 9006
Post by: Mark Wilkinson on June 19, 2018, 04:51:52 pm
Figured I follow up for anyone seeking the same questions.

I went to RCF and had a demo of the subs and the hdl20 and hdl30. 

First off, both subs sound amazing.  One will easily put out what two of my srx828 will.

The 9006 was my favorite.  It had incredible punch and the clarity was some of the best I've heard in a sub.  I was very impressed.

Do you know what drivers are in the 9006? 
Everyone seems impressed by it..

thx,  mark
Title: Re: Rcf 8006 and 9006
Post by: Geert Friedhof on June 20, 2018, 06:07:37 am
Get the 9006 if you buy new and can afford them.

Get the 8006 if you can't, or if you get a great deal on demo/second hand.
Title: Re: Rcf 8006 and 9006
Post by: David Morison on June 20, 2018, 09:26:43 am
Do you know what drivers are in the 9006? 
Everyone seems impressed by it..

thx,  mark

IIRC, in an earlier thread an RCF rep pointed out that they don't use off the shelf units from their standard product line for their own boxes.
So although it'd be nice to model what might be used, it won't be as simple as finding the highest powered, longest excursion example from that range and assuming it'll be a match.
Title: Re: Rcf 8006 and 9006
Post by: Mark Wilkinson on June 20, 2018, 04:30:24 pm
IIRC, in an earlier thread an RCF rep pointed out that they don't use off the shelf units from their standard product line for their own boxes.
So although it'd be nice to model what might be used, it won't be as simple as finding the highest powered, longest excursion example from that range and assuming it'll be a match.

That's what i suspected, thx.
Plus, RCF doesn't list an 18" that matches the power specs in the 9006.
Title: Re: Rcf 8006 and 9006
Post by: Marjan Milosevic on June 21, 2018, 11:46:41 am
That's what i suspected, thx.
Plus, RCF doesn't list an 18" that matches the power specs in the 9006.

Power spec is for the amplifier section, not the drivers.
Look for the biggest 4 inch voice coil 18 they do, should be that one, or a very close derivative.
Title: Re: Rcf 8006 and 9006
Post by: Geert Friedhof on June 21, 2018, 05:53:08 pm
Power spec is for the amplifier section, not the drivers.
Look for the biggest 4 inch voice coil 18 they do, should be that one, or a very close derivative.

Close, but no sigar.

8006 should be a 401 derivatve, 9006 a 405 or something, but with a different coil to bring the impedance down, so the amp has to work harder.

Title: Re: Rcf 8006 and 9006
Post by: Tim Hite on June 22, 2018, 02:22:14 am
Eddie Limon at Above the Crowd is currently selling off a dozen lightly used 8006's

http://atcprod.com

Get the 9006 if you buy new and can afford them.

Get the 8006 if you can't, or if you get a great deal on demo/second hand.
Title: Re: Rcf 8006 and 9006
Post by: Miguel Dahl on September 13, 2018, 06:18:17 am
When I was down at RCF this summer and asked about the 9006 the guy told me that the drivers had double "something". I didn't understand what he said. Double windings, coils, double what.. That sub sounds amazing at least.
Title: Re: Rcf 8006 and 9006
Post by: Chris Grimshaw on September 13, 2018, 08:08:48 am
When I was down at RCF this summer and asked about the 9006 the guy told me that the drivers had double "something". I didn't understand what he said. Double windings, coils, double what.. That sub sounds amazing at least.

Double voice coils, maybe.
Could also just be double-layer - inside/outside winding is pretty common.

Chris
Title: Re: Rcf 8006 and 9006
Post by: Art Welter on September 13, 2018, 11:36:37 am
Double windings, coils, double what..
RCF makes a number of drivers with dual wound inside/outside  voice coils, dual "Forced Hyperventing", and dual spiders.

A trio of doubles...
Title: Re: Rcf 8006 and 9006
Post by: Luis_Marquez on September 29, 2018, 02:49:33 pm
 

First off, both subs sound amazing.  One will easily put out what two of my srx828 will.

The 9006 was my favorite.  It had incredible punch and the clarity was some of the best I've heard in a sub.  I was very impressed.

This is the third time I read of “One will put out what two of my subs will”. What makes this possible? So with this statement, Will a single 9004 put out what one srx828p will?
Title: Re: Rcf 8006 and 9006
Post by: Caleb Dueck on September 29, 2018, 03:21:44 pm
Has anyone heard the 9006 and Bassboss SSP218?  Both look to be excellent, self-powered, dual 18" front loaded subs above the typical MI grade (QSC/JBL/EV/EAW RSX/etc) level. 

Past that - how do the above compare to Meyer?  Is Meyer really 3x better?

Sent from my VS980 4G using Tapatalk

Title: Re: Rcf 8006 and 9006
Post by: Scott Holtzman on September 30, 2018, 01:17:19 am
Our 20+ year old Meyer 650 R2 on paper should be wimps but 6 of them outrun 6 STX828, 12 easily handle outdoor crowds of 5000+ with rock/blues.

I should measure them sometime. 

Sent from my VS996 using Tapatalk

Title: Re: Rcf 8006 and 9006
Post by: Art Welter on September 30, 2018, 02:33:52 pm
This is the third time I read of “One will put out what two of my subs will”. What makes this possible? So with this statement, Will a single 9004 put out what one srx828p will?
Luis,

Without direct measurement of both, hard to answer the question.

That said, the SRX828 uses 2242H drivers which have an Xmax (linear excursion) of only 7.87 mm, not a lot for a 21st century subwoofer.
There are many current drivers with double or more that Xmax, doubling Xmax (given the power to achieve it) results in 6 dB more output, the equivalent of doubling drivers and power.

Art

Title: Re: Rcf 8006 and 9006
Post by: Michael Storey on October 01, 2018, 02:22:17 am
Luis,

Without direct measurement of both, hard to answer the question.

That said, the SRX828 uses 2242H drivers which have an Xmax (linear excursion) of only 7.87 mm, not a lot for a 21st century subwoofer.

Art

Not to nitpick, but the SRX828s actually uses 2279H drivers. I can't find official specs online, but I've read that other than the 2279's ceramic magnet structure, they are pretty similar to the 2268H and share the same recone kit.
Title: Re: Rcf 8006 and 9006
Post by: Art Welter on October 01, 2018, 12:11:02 pm
Not to nitpick, but the SRX828s actually uses 2279H drivers. I can't find official specs online, but I've read that other than the 2279's ceramic magnet structure, they are pretty similar to the 2268H and share the same recone kit.
Michael,

The 2268H is also around 8mm Xmax.

I was just going from the JBL SRX828s spec sheet, did they change from the 2242H?

Art


Title: Re: Rcf 8006 and 9006
Post by: John L Nobile on October 01, 2018, 12:31:01 pm
Our 20+ year old Meyer 650 R2 on paper should be wimps but 6 of them outrun 6 STX828, 12 easily handle outdoor crowds of 5000+ with rock/blues.

I should measure them sometime. 

Sent from my VS996 using Tapatalk

Do you have the original drivers in them?
Title: Re: Rcf 8006 and 9006
Post by: Scott Holtzman on October 01, 2018, 01:35:17 pm
Do you have the original drivers in them?
Comparing Danley TH118 (I think I want to upgrade to these), STX828S (the JBL'ss I have 6 of them, our B system) and Meyer 650-R2 (we have 12 of these, our A system)

I found this thread interesting, can I really replace my workhorse Meyer's 2:1.  This is what I came up with (specs on the bottom). 


The amazing thing,  The Danley's are about 4 db continuous and 6db apart from the Meyer.


The JBL's don't go as low but are really inefficient, taking shitloads of power to do the same thing..  99db efficient, again about 6db so they need at least 3000 watts to do what the Meyers do on with a 1000.


The Danley's would replace the Meyer's 2:1 but need three times as much power. 


The JBL's should keep up with the Meyer's but they don't and they are nowhere near as musical.


The Meyer's are paid for and despite their age nobody would turn them down.

The Meyer's and the Danley TH118XL's are about an inch apart in dimensions.


Interesting stuff. 

Meyer 650R2 in Column 1, Danley TH118XL in Center Column, JBL STX828S in third column

(https://uploads.tapatalk-cdn.com/20181001/bce86478f9b4a1a5e4134bd9e934742f.jpg)

Sent from my VS996 using Tapatalk

Title: Re: Rcf 8006 and 9006
Post by: Taylor Hall on October 01, 2018, 02:21:08 pm
Snip
Seems like the iron triangle is hard to escape in pretty much every aspect of this business. It's always a worthwhile exercise to compare options and see if gains in any given area would justify the cost. I often have to be the voice of reason when the "Oooh shiny!" impulse strikes at new gear haha
Title: Re: Rcf 8006 and 9006
Post by: Michael Storey on October 01, 2018, 02:58:42 pm
Michael,

The 2268H is also around 8mm Xmax.

I was just going from the JBL SRX828s spec sheet, did they change from the 2242H?

Art

The spec sheet you're referencing is for the *STX* 828s, which does use the old 2242H. The *SRX* 828s is the subwoofer model in question in the posts that you were responding to. Easy to mix up!

 
Title: Re: Rcf 8006 and 9006
Post by: Scott Holtzman on October 01, 2018, 03:03:34 pm
The spec sheet you're referencing is for the *STX* 828s, which does use the old 2242H. The *SRX* 828s is the subwoofer model in question in the posts that you were responding to. Easy to mix up!

 

No mixup I have STX's not SRX's.

It's interesting that JBL quotes the SRX's 3db hotter in MAX SPL.  Without a frequency range it's a meaningless number.

The Meyer quotes continuous SPL.

 

Title: Re: Rcf 8006 and 9006
Post by: Tim Hite on October 01, 2018, 04:36:53 pm
Man, I'd sure be hard pressed to replace paid off Meyer gear with anything else. That logo sure seems to count for a lot in this business.

Comparing Danley TH118 (I think I want to upgrade to these), STX828S (the JBL'ss I have 6 of them, our B system) and Meyer 650-R2 (we have 12 of these, our A system)

I found this thread interesting, can I really replace my workhorse Meyer's 2:1.  This is what I came up with (specs on the bottom). 


The amazing thing,  The Danley's are about 4 db continuous and 6db apart from the Meyer.


The JBL's don't go as low but are really inefficient, taking shitloads of power to do the same thing..  99db efficient, again about 6db so they need at least 3000 watts to do what the Meyers do on with a 1000.


The Danley's would replace the Meyer's 2:1 but need three times as much power. 


The JBL's should keep up with the Meyer's but they don't and they are nowhere near as musical.


The Meyer's are paid for and despite their age nobody would turn them down.

The Meyer's and the Danley TH118XL's are about an inch apart in dimensions.


Interesting stuff. 

Meyer 650R2 in Column 1, Danley TH118XL in Center Column, JBL STX828S in third column

(https://uploads.tapatalk-cdn.com/20181001/bce86478f9b4a1a5e4134bd9e934742f.jpg)

Sent from my VS996 using Tapatalk
Title: Re: Rcf 8006 and 9006
Post by: Mark Wilkinson on October 01, 2018, 04:46:21 pm

I found this thread interesting, can I really replace my workhorse Meyer's 2:1.  This is what I came up with (specs on the bottom). 



Sent from my VS996 using Tapatalk

Hi Scott, I don't have any of the subs you have, or a TH-118. 
But I've spent a lot of time comparing JTR orbitshifter and labhorns to some of my DIY double 18 designs and a pair of Meyer mts4a's sitting on top of a 650-p, which ends up being four 18" and 2 15" all cranking together.

For high quality double 18"s, I wouldn't count on a 2:1 replacement ratio from a horn sub.   
My gut says I'd better be ready to settle for 3:2.....especially if digging down low.
Title: Re: Rcf 8006 and 9006
Post by: Spenser Hamilton on October 01, 2018, 04:47:15 pm
Man, I'd sure be hard pressed to replace paid off Meyer gear with anything else. That logo sure seems to count for a lot in this business.

+1 Unless you are losing business, there isn't much reason to change.
Title: Re: Rcf 8006 and 9006
Post by: Scott Holtzman on October 01, 2018, 04:58:43 pm
Hi Scott, I don't have any of the subs you have, or a TH-118. 
But I've spent a lot of time comparing JTR orbitshifter and labhorns to some of my DIY double 18 designs and a pair of Meyer mts4a's sitting on top of a 650-p, which ends up being four 18" and 2 15" all cranking together.

For high quality double 18"s, I wouldn't count on a 2:1 replacement ratio from a horn sub.   
My gut says I'd better be ready to settle for 3:2.....especially if digging down low.

Agree and that's why I am trying to expand the scope of the thread.  While it is about the RCF's it is the same theme as many.

The query always seems to be should I spend money on one sub over another.

From the lounge level of 2-4 boxes up to the regional provider the economics of the upgrades just never seems to make sense.  Even at 2:1 how long does it take to load 6 extra cabinets on the truck and transport them?

The difference between the subs at this level seems very minimal both on paper and in the real world.


 
Title: Re: Rcf 8006 and 9006
Post by: Ivan Beaver on October 01, 2018, 08:49:05 pm
Agree and that's why I am trying to expand the scope of the thread.  While it is about the RCF's it is the same theme as many.

The query always seems to be should I spend money on one sub over another.

From the lounge level of 2-4 boxes up to the regional provider the economics of the upgrades just never seems to make sense.  Even at 2:1 how long does it take to load 6 extra cabinets on the truck and transport them?

The difference between the subs at this level seems very minimal both on paper and in the real world.
The problem is the "simple paper numbers" only give part of the answer.

There is much to the sound that simple numbers simply cannot do.

And unless they are measured in the same way/conditions, simply numbers can give very misleading answers.

A much better way than the simple numbers is to look at the UNPROCESSED freq response, for a giving input signal level and measurement distance.

THEN you have something to start to compare actual capabilities.  You must assume the wattage rating is accurate, so you have a know multiplier for the total SPL.

But you also don't know the distortion etc, which can greatly affect the sound, or what they sound like with the max applied signal.

That is where the side by side tests come into play.
Title: Re: Rcf 8006 and 9006
Post by: Scott Holtzman on October 01, 2018, 08:59:12 pm
The problem is the "simple paper numbers" only give part of the answer.

There is much to the sound that simple numbers simply cannot do.

And unless they are measured in the same way/conditions, simply numbers can give very misleading answers.

A much better way than the simple numbers is to look at the UNPROCESSED freq response, for a giving input signal level and measurement distance.

THEN you have something to start to compare actual capabilities.  You must assume the wattage rating is accurate, so you have a know multiplier for the total SPL.

But you also don't know the distortion etc, which can greatly affect the sound, or what they sound like with the max applied signal.

That is where the side by side tests come into play.

Agree on all that....The Meyer does quote distortion "Total harmonic distortion shallbe less than 3% at 130 dB SPL one meteron axis at 60 Hz"

You are also right, they don't work well without the factory processors.
Title: Re: Rcf 8006 and 9006
Post by: Tim McCulloch on October 01, 2018, 11:33:56 pm
Agree and that's why I am trying to expand the scope of the thread.  While it is about the RCF's it is the same theme as many.

The query always seems to be should I spend money on one sub over another.

From the lounge level of 2-4 boxes up to the regional provider the economics of the upgrades just never seems to make sense.  Even at 2:1 how long does it take to load 6 extra cabinets on the truck and transport them?

The difference between the subs at this level seems very minimal both on paper and in the real world.

Scott,  the "next axioms" to go with:

1) The wrong product at the right price is still the wrong product
2) Buy once, cry once

3) Profit potential/expense minimization is set at the time of initial purchase decisions
4) Excess capacity is infinitely expensive and lateral moves are usually just plain dumb

Title: Re: Rcf 8006 and 9006
Post by: Scott Holtzman on October 02, 2018, 01:56:28 am
Scott,  the "next axioms" to go with:

1) The wrong product at the right price is still the wrong product
2) Buy once, cry once

3) Profit potential/expense minimization is set at the time of initial purchase decisions
4) Excess capacity is infinitely expensive and lateral moves are usually just plain dumb
You have shared all of those before Tim.  I have taken all to heart.

People never learn and we see these posts with folks hoping for huge performance gains or clients to flock to them with a new set of xXxX.

I do know the economics change at the top end of the business.  The rest of us need to spend the time running our business, improving process, marketing ot just listening to your customers,

All this teeth knashing over gear selection seems a grand waste of time.

Sent from my VS996 using Tapatalk

Title: Re: Rcf 8006 and 9006
Post by: Mark Wilkinson on October 02, 2018, 09:55:12 am
The problem is the "simple paper numbers" only give part of the answer.

There is much to the sound that simple numbers simply cannot do.

And unless they are measured in the same way/conditions, simply numbers can give very misleading answers.

A much better way than the simple numbers is to look at the UNPROCESSED freq response, for a giving input signal level and measurement distance.

THEN you have something to start to compare actual capabilities.  You must assume the wattage rating is accurate, so you have a know multiplier for the total SPL.

But you also don't know the distortion etc, which can greatly affect the sound, or what they sound like with the max applied signal.

That is where the side by side tests come into play.


Sure, side by side testing is the only real way to know. For sure.

And yes, looking at unprocessed response curves is much better than paying any attention to simple numbers.
I mean look at the TH-118XL curve for example, compared to its simple number sensitivity of 108 dB.
Heck, the only time the curve shows above 108, is between maybe 120 to 170Hz.....?????

In fairness, the Architech specs say 105 dB....but my read of the curve says I better knock that down a couple, given I shoot for a 35Hz f3 and low pass at 100Hz.

I know we've had this discussion before, but IMSO, all real world side by side listening and measuring, should be done with processing in place
Sensitivity can be measured, not eyeballed against a curve. 
Max SPL and distortion needs to be heard with processing in place, as we push subs at equal levels.
Who cares what unprocessed response is when the rubber meets the road?

Besides, with so many of today's subs being self-powered, the whole processed vs unprocessed comparison becomes moot...
Title: Re: Rcf 8006 and 9006
Post by: Mark Wilkinson on October 02, 2018, 10:02:13 am

All this teeth knashing over gear selection seems a grand waste of time.


Amen.  The more time I spend getting competent with what I have....the smaller the variances between new gear and old.

I get reminded of the golf adage by Lee Trevino .....'"a pro will beat you with an umbrella"

Title: Re: Rcf 8006 and 9006
Post by: Ivan Beaver on October 02, 2018, 04:22:11 pm

Sure, side by side testing is the only real way to know. For sure.

And yes, looking at unprocessed response curves is much better than paying any attention to simple numbers.
I mean look at the TH-118XL curve for example, compared to its simple number sensitivity of 108 dB.
Heck, the only time the curve shows above 108, is between maybe 120 to 170Hz.....?????

In fairness, the Architech specs say 105 dB....but my read of the curve says I better knock that down a couple, given I shoot for a 35Hz f3 and low pass at 100Hz.

This is a good example of where the data from engineering gets entered wrong by others.

Thanks for the heads up-I have already passed the error onto the "parties that be" to be changed.

It got missed somewhere.

The sensitivity should be 105dB.

Regarding where someone feels the "low freq point" should be, is exactly why the data is presented.

just like impedance.  We provide a standard number, but the user can look at the curve and determine what they feel best represents the actual number-since a simple single number can't do that.

Without a graph, there is no way to know where the numbers came from
Title: Re: Rcf 8006 and 9006
Post by: David Morison on October 03, 2018, 04:08:25 am

just like impedance.  We provide a standard number, but the user can look at the curve and determine what they feel best represents the actual number-since a simple single number can't do that.

Without a graph, there is no way to know where the numbers came from

Just looked at the pdf and webpage for the 118XL - no impedance curve in sight. Don't suppose you could get that fixed too please?
Title: Re: Rcf 8006 and 9006
Post by: Ivan Beaver on October 03, 2018, 08:19:12 am
Just looked at the pdf and webpage for the 118XL - no impedance curve in sight. Don't suppose you could get that fixed too please?
I sent in that request also.

BTW how many other manufacturers show impedance curves of products?

Not very many it seems these days.  Most don't even show a freq response plot.


Title: Re: Rcf 8006 and 9006
Post by: Ivan Beaver on October 03, 2018, 08:21:43 am
Just looked at the pdf and webpage for the 118XL - no impedance curve in sight. Don't suppose you could get that fixed too please?
Here it is
Title: Re: Rcf 8006 and 9006
Post by: David Morison on October 03, 2018, 08:46:39 am
Here it is

Thanks Ivan  :D
Title: Re: Rcf 8006 and 9006
Post by: Peter Morris on October 03, 2018, 11:14:01 am
This is a good example of where the data from engineering gets entered wrong by others.

The sensitivity should be 105dB.



...and if you measure it the same way as almost everyone else 102 dB w/m :)
Title: Re: Rcf 8006 and 9006
Post by: John Schalk on October 03, 2018, 11:52:06 am
Regarding where someone feels the "low freq point" should be, is exactly why the data is presented.

just like impedance.  We provide a standard number, but the user can look at the curve and determine what they feel best represents the actual number-since a simple single number can't do that.

Without a graph, there is no way to know where the numbers came from

If RCF published frequency response graphs for the 8006 & 9006 perhaps there would be fewer requests from Labsters for the subjective opinions of others as to how they compare.  I particularly appreciate Ivan's remarks regarding how a frequency response graph allows us to make our own determination of the -3dB spec (or whatever) for a given sub.

The band I work for owns EV PX2181s.  They are an incarnation of EV's "horn-loaded sub-scoop" design.  The spec sheet lists them as -3db at 45Hz, but when I look at the chart (thank you EV), using the response from 60-90 as the reference, I conclude that the -3dB point is a bit higher than that.  That's helpful to me because one possible sub that I might buy is the ThMini 15 which has a -3dB spec of 50Hz which sounded too high to me until I looked up the actual response of the subs I mix on every week.

Unfortunately, almost none of the big boys publish the frequency response of their subs anymore.  A great illustration of this issue is the DVA S30n.  It has a published -3dB spec of 30Hz and a maximum output of 141dB.  Sounds great!  However, I found a Youtube review of the sub by TrinityProSound that includes some informal objective response information which makes it clear that this quasi-horn design has very limited response below 50Hz relative to the 60-90 range.  I have no idea how they can give it a -3dB rating of 30Hz based on what is shown in that video and we all must assume that the same thing is true for all of the other claimed responses that aren't backed up with object graphs.
Title: Re: Rcf 8006 and 9006
Post by: Mark Wilkinson on October 03, 2018, 12:22:05 pm
This is a good example of where the data from engineering gets entered wrong by others.

Thanks for the heads up-I have already passed the error onto the "parties that be" to be changed.


You bet Ivan,

I second the John S appreciation for the response curves you guys provide.

I guess the engineer in me is always looking for more hard data that's truly comparable.
 
FWIW, I'd rate Fulcrum's specs as the most useful I've seen.....
particularly because they show both raw and processed curves....
as well as polars/directivity and impedance curves.

Given how well your products would look under the same set of graphs, I often wonder why Danley doesn't show all those.
I guess in fairness, the install market looks more to modeling than specs?  for which you have Danley Direct



Title: Re: Rcf 8006 and 9006
Post by: Ivan Beaver on October 03, 2018, 01:05:08 pm
...and if you measure it the same way as almost everyone else 102 dB w/m :)
OORRRRR  I fyou use the "1 watt" method-how DO you apply 1 watt to the loudspeaker at all freq?  You don't, you apply A VOLTAGE, and the power is calculated-based on some impedance.

So if you use the 1 watt method and use the impedance peak around 41Hz as your "standard", you get to add 4.77dB to the sensitivity.

That is EXACTLY why Danley uses 2.83V for ALL models.   No matter the impedance

It keeps the drive level the same
Title: Re: Rcf 8006 and 9006
Post by: Ivan Beaver on October 03, 2018, 01:14:39 pm
If RCF published frequency response graphs for the 8006 & 9006 perhaps there would be fewer requests from Labsters for the subjective opinions of others as to how they compare.  I particularly appreciate Ivan's remarks regarding how a frequency response graph allows us to make our own determination of the -3dB spec (or whatever) for a given sub.

The band I work for owns EV PX2181s.  They are an incarnation of EV's "horn-loaded sub-scoop" design.  The spec sheet lists them as -3db at 45Hz, but when I look at the chart (thank you EV), using the response from 60-90 as the reference, I conclude that the -3dB point is a bit higher than that.  That's helpful to me because one possible sub that I might buy is the ThMini 15 which has a -3dB spec of 50Hz which sounded too high to me until I looked up the actual response of the subs I mix on every week.

Unfortunately, almost none of the big boys publish the frequency response of their subs anymore.  A great illustration of this issue is the DVA S30n.  It has a published -3dB spec of 30Hz and a maximum output of 141dB.  Sounds great!  However, I found a Youtube review of the sub by TrinityProSound that includes some informal objective response information which makes it clear that this quasi-horn design has very limited response below 50Hz relative to the 60-90 range.  I have no idea how they can give it a -3dB rating of 30Hz based on what is shown in that video and we all must assume that the same thing is true for all of the other claimed responses that aren't backed up with object graphs.
There is one sub from a brand that gets mentioned here all the time.

It has a stated -3dB of 30Hz.  But on THEIR OWN GRAPH, the level at 30Hz is actually 27dB down from the rated sensitivity.

It must be that "new math" they are using.

People often forget that -3dB HAS NO MEANING WHAT SO EVER,  It can be ANYTHING somebody wants it to be.

It simply means that the particular freq is 3 dB lower than "something else".

If the "something else" is not stated, then the number is meaningless.

But in order to make some sort of sense, the -3dB SHOULD be 3dB down from the rated sensitivity.

SO a manufacturer can choose to have a higher rated sensitivity (at some peak freq) but they ALSO must accept a higher -3dB cutoff.

Or they can have a lower -3dB point, but then the rated sensitivity must also be lower.

That is why graphs are so important.  You can look at a graph and choose whatever numbers YOU feel are important, and not have to guess as to what the manufacturer was choosing for numbers.
Title: Re: Rcf 8006 and 9006
Post by: Mike Pyle on October 03, 2018, 01:17:19 pm
If RCF published frequency response graphs for the 8006 & 9006 perhaps there would be fewer requests from Labsters for the subjective opinions of others as to how they compare.  I particularly appreciate Ivan's remarks regarding how a frequency response graph allows us to make our own determination of the -3dB spec (or whatever) for a given sub....

They do publish charts. Being powered cabs these of course are post processing. They also would appear to have the lowpass at the 50Hz setting.

https://www.rcf.it/c/document_library/get_file?uuid=ccc1d690-e611-4484-920d-45bbd2aa5660&groupId=20195

https://www.rcf.it/c/document_library/get_file?uuid=96242f83-a0e2-47ec-a970-f70f5bbf33c8&groupId=20195
Title: Re: Rcf 8006 and 9006
Post by: Taylor Hall on October 03, 2018, 01:37:37 pm

That is why graphs are so important.  You can look at a graph and choose whatever numbers YOU feel are important, and not have to guess as to what the manufacturer was choosing for numbers.
Yet another way that the auto industry and the pro audio world overlap. Numbers by themselves look great on paper, but when you're able to see what does (or in most cases, doesn't) lie under the curve, the shiny marketing doublespeak quickly rubs off to reveal a rather tarnished finished product in reality.
Title: Re: Rcf 8006 and 9006
Post by: Peter Morris on October 03, 2018, 08:48:37 pm
OORRRRR  I fyou use the "1 watt" method-how DO you apply 1 watt to the loudspeaker at all freq?  You don't, you apply A VOLTAGE, and the power is calculated-based on some impedance.

So if you use the 1 watt method and use the impedance peak around 41Hz as your "standard", you get to add 4.77dB to the sensitivity.

That is EXACTLY why Danley uses 2.83V for ALL models.   No matter the impedance

It keeps the drive level the same

Well, it’s a nominal rating so what everyone else does is use 2 volts RMS for 4 ohm speakers and 2.83 for 8 ohms ... your box has a nominal impedance of 4 ohms.  By doing that it gives us a better way to compare different manufactures products and not mislead people who have not read or misunderstood the fine print regarding sensitivity specification .... I have had many people do this with your boxes when they compare them with others.
Title: Re: Rcf 8006 and 9006
Post by: Art Welter on October 04, 2018, 01:52:32 am
Well, it’s a nominal rating so what everyone else does is use 2 volts RMS for 4 ohm speakers and 2.83 for 8 ohms ... your box has a nominal impedance of 4 ohms.  By doing that it gives us a better way to compare different manufactures products and not mislead people who have not read or misunderstood the fine print regarding sensitivity specification .... I have had many people do this with your boxes when they compare them with others.
Peter,

Right, not everybody got the memo 9-10 years ago when Ivan was explaining to all of us why DSL decided to not bother adjusting voltage to the nominal impedance...
The discussions went on for pages and weeks, with specs like the ones on the 4 ohm TH-115 going through revisions to help support the decision for DSL to "choose to have a higher rated sensitivity" than what the nominal voltage used would suggest.

Art
Title: Re: Rcf 8006 and 9006
Post by: John Schalk on October 08, 2018, 12:54:57 pm
They do publish charts. Being powered cabs these of course are post processing. They also would appear to have the lowpass at the 50Hz setting.

https://www.rcf.it/c/document_library/get_file?uuid=ccc1d690-e611-4484-920d-45bbd2aa5660&groupId=20195

https://www.rcf.it/c/document_library/get_file?uuid=96242f83-a0e2-47ec-a970-f70f5bbf33c8&groupId=20195

Thanks Mike.  I am not sure how I missed those before.  Unfortunately, after comparing the two graphs side by side, it's clear that RCF used two very different system settings when they measured each sub.  I'm guessing that the 8006's response is with the Punch button engaged ("This switch provides a DEEP equalization (flat response down to 30 Hz) or a PUNCH equalization with a boosted equalization at 70 Hz.") and the low pass set to 80 Hz.  The 9006 appears to be measured from 30 Hz to 50 Hz without any similar tonal Eq.  Also, both graphs indicate -20dBu/1M but the output of the 8006 is roughly 6 dB higher at 50 Hz from that of the 9006.

What can we conclude from comparing the two graphs?  I guess it's clear that the 9006 is capable of a -3 dB response at 30 Hz relative to 50 Hz.  And we can see what the output of the 8006 looks like in Punch mode if my assumption is correct.  I don't think we can conclude that the 8006 is 6 dB louder than the 9006 though.  Since both of these subs are out of my price range, this is mostly academic to me anyway :)