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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB: The Classic Live Audio Board => Topic started by: Riley Casey on February 08, 2019, 11:09:24 AM

Title: B&C 14" coax for wedges ?
Post by: Riley Casey on February 08, 2019, 11:09:24 AM
I've liked coax's for a long time and I've often thought that something between a 12" and a 15" could be a real sweet spot for stage monitor use.  Low and behold B&C now makes a 13.5" coax driver with a neo magnet. ( 14CXN88 )  Seems promising but on the other hand I know that Turbo uses the B&C 12s and 15s in their near MI grade wedges and those I have not been overwhelmed with.  Might be how they were implemented by Turbo and the vendor for those shows but it gives me pause.  Has anyone heard the B&C 14" speakers and have any opinions?
Title: Re: B&C 14" coax for wedges ?
Post by: Art Welter on February 08, 2019, 08:14:54 PM
...on the other hand I know that Turbo uses the B&C 12s and 15s in their near MI grade wedges and those I have not been overwhelmed with.  Might be how they were implemented by Turbo and the vendor for those shows but it gives me pause.  Has anyone heard the B&C 14" speakers and have any opinions?
Riley,

The B&C14CXN88 does look like a very nice driver!
I have not heard the new 14CXN88, but I doubt that the drivers used in the Turbo "near MI grade wedges" are of that grade.
 
See Peter Morris reply #14:
https://forums.prosoundweb.com/index.php/topic,163665.10.html

Although Turbo did use B&C prior to Behringer, are you sure the newer units you heard actually do use B&C?

And even if they do use B&C, there are a lot of price points available in their line, and OEM products that may not have even have any spec sheets available to us, making comparisons difficult.

Art
Title: Re: B&C 14" coax for wedges ?
Post by: Steven Eudaly on February 09, 2019, 01:43:19 AM
FWIW, we have 12x d&b Max2 wedges, a single-15" passive coax. Everyone loves them, engineers and artists alike. I'm guessing that driver performs very similarly in the right cabinet.
Title: Re: B&C 14" coax for wedges ?
Post by: Mark Wilkinson on February 09, 2019, 11:57:06 AM
I flipped a coin whether to get the 14cxn88 or the 15cxn88.
Like you, I liked the idea of the 14" for a wedge.
But i liked the 15" a little better for a crazy morph off the Danley SM-80....the idea being to add a bit of cone to the coax ala the sm-80, but with ports to go lower, and maybe a plate amp...

15" won the toss, so I've been playing with the morph idea first....first iteration was attached pict ...it's working very well, but there's still a few things to try..

As soon as that project is over, I'm going to give a wedge a go..
I don't have much experience with wedges, so I doubt any observations about what I build would be of real value to you guys...

All that said, I do like the driver a lot.  So far, it's a pretty neat one-driver solution for a main.
 
Maybe I paid too much, but I can't see these drivers making their way into anything other than premium wedges..




Title: Re: B&C 14" coax for wedges ?
Post by: Steve Payne on February 09, 2019, 12:32:14 PM
I've liked coax's for a long time and I've often thought that something between a 12" and a 15" could be a real sweet spot for stage monitor use.  Low and behold B&C now makes a 13.5" coax driver with a neo magnet. ( 14CXN88 )  Seems promising but on the other hand I know that Turbo uses the B&C 12s and 15s in their near MI grade wedges and those I have not been overwhelmed with.  Might be how they were implemented by Turbo and the vendor for those shows but it gives me pause.  Has anyone heard the B&C 14" speakers and have any opinions?

A 13.5" coax in a wedge sounds intriguing.  (See what I did there?)  I have B&C drivers in a LOT of OEM speakers, as well as original Turbo TFM122.  (Which may have been what you heard at RFF and didn't like?? - Though it seems more likely that you may have heard the new Behringer made plastic end cheek TFM122 knock offs which use Chinese made speakers.)  Be that as it may, why don't you give Bennet Prescott a shout about the speaker you are interested in?  He is all things B&C/USA. 
Title: Re: B&C 14" coax for wedges ?
Post by: Peter Morris on February 09, 2019, 09:06:59 PM
A 13.5" coax in a wedge sounds intriguing.  (See what I did there?)  I have B&C drivers in a LOT of OEM speakers, as well as original Turbo TFM122.  (Which may have been what you heard at RFF and didn't like?? - Though it seems more likely that you may have heard the new Behringer made plastic end cheek TFM122 knock offs which use Chinese made speakers.)  Be that as it may, why don't you give Bennet Prescott a shout about the speaker you are interested in?  He is all things B&C/USA.

There is also an even cheaper TFX range ....

http://www.musictribe.com/Categories/Turbosound/FLASHLINE-MONITORS/TFX122M-AN/p/P0BMU   https://www.sweetwater.com/store/detail/TFX122MAN--turbosound-tfx122m-an-flashline-series-2-way-stage-monitor-12-inch

FWIW I used the "real" TFM115's ( https://bcspeakers.com/en/products/coaxial/15-0/8/15hcx76 ) last night with an old national level act, its was the engineers 624th show with the band  - he gets to use a lot of diffent systems - and he commented how much he like the wedges.
Title: Re: B&C 14" coax for wedges ?
Post by: Steve Payne on February 10, 2019, 05:12:52 PM
There is also an even cheaper TFX range ....

http://www.musictribe.com/Categories/Turbosound/FLASHLINE-MONITORS/TFX122M-AN/p/P0BMU   https://www.sweetwater.com/store/detail/TFX122MAN--turbosound-tfx122m-an-flashline-series-2-way-stage-monitor-12-inch

FWIW I used the "real" TFM115's ( https://bcspeakers.com/en/products/coaxial/15-0/8/15hcx76 ) last night with an old national level act, its was the engineers 624th show with the band  - he gets to use a lot of diffent systems - and he commented how much he like the wedges.

The original TFM series monitors are a no apologies necessary tool in my opinion.  I am very happy with the TFM112s and TFM560s we have.  I have never had an engineer complain about them. 
Title: Re: B&C 14" coax for wedges ?
Post by: Jim McKeveny on February 13, 2019, 07:35:36 AM
In my experience, coax speakers that utilize both a large VC/large exit HF with a waveguide are the most consistent performers.
Title: Re: B&C 14" coax for wedges ?
Post by: Riley Casey on February 13, 2019, 10:15:31 AM
That was a part of what prompted me to ask if anyone had experience with these coaxes.  The fact that they are depending on the cone surface as a waveguide extension for the HF is not encouraging.

In my experience, coax speakers that utilize both a large VC/large exit HF with a waveguide are the most consistent performers.
Title: Re: B&C 14" coax for wedges ?
Post by: Chris Grimshaw on February 13, 2019, 10:38:59 AM
That was a part of what prompted me to ask if anyone had experience with these coaxes.  The fact that they are depending on the cone surface as a waveguide extension for the HF is not encouraging.

It's not necessarily a bad thing. Having a HF horn suspended in the middle of the LF cone means there's a lot of room for diffraction to come in - see if you can find some graphs of raw horns vs mounted in a baffle. The differences aren't subtle.
Then there's reflections from the midbass driver against the back of the horn - you'll need a low crossover to get around that, which means more strain on the HF driver, while the horn isn't really big enough to load down low anyway.

So, I'm not sure it's as clear-cut as simply having a horn makes the coaxial better - everything's a compromise.

FWIW, I'm working on a passive 10" coaxial monitor at the moment. The cone is part of the HF horn. Sounds fine, with a response smooth enough to be more-than-just-usable with four crossover components. A few dB of EQ does get it sounding better, though.
Can't say much more than that - the manufacturer wants rights to the cabinet and crossover designs.

Chris
Title: Re: B&C 14" coax for wedges ?
Post by: Uwe Riemer2 on February 13, 2019, 01:45:21 PM
That was a part of what prompted me to ask if anyone had experience with these coaxes.  The fact that they are depending on the cone surface as a waveguide extension for the HF is not encouraging.

Well, Danley uses a 12" cousin and we all heard, how capable this box is.

I cannot tell you something about this specific driver, but I have designed a wedge with the 14CXN76.
My box is good, as long as I dont need serious ( 3x 4x12" Marshall on stage ) kick and snare out of it.

So if you want to wait a year or so, I am pretty sure, that I will have an opinion about the 14CXN88
Title: Re: B&C 14" coax for wedges ?
Post by: Riley Casey on February 13, 2019, 07:52:56 PM
Only way to find out is to rattle Bennettís cage.  No retail links coming up.  Makes me think itís not getting a lot of traction.
Title: Re: B&C 14" coax for wedges ?
Post by: Frank Koenig on February 13, 2019, 09:01:38 PM
The fact that they are depending on the cone surface as a waveguide extension for the HF is not encouraging.

Riley, I'm not sure where you're getting that. I'm not a driver designer but I have built systems around three modern coaxes, two of which have rigid horns that extend beyond the woofer dust cap and one where the horn melds into the woofer cone, as is the case with this diver and the similar one that Danley uses in the much celebrated (here at least) SM80. I've also looked at a lot of published response curves. My observation is that the coaxes with protruding horns have less overlap between the passbands and are generally more challenging to design crossovers for.

I presume the extended horn can get you a narrower pattern at the highest frequencies and perhaps a bit more efficiency. But given that newer B&C (as well as other) HF compression drivers can get stupid loud and sound pretty good doing it, horn efficiency sufficient to keep up with a single 12 to 15 in. cone driver is not likely an issue. (The SH96 uses a single B&C Ti diaphragm driver in a conical horn crossed at ~1kHz to keep up with 4 15 in. woofers, for example.) To be sure, these coax speakers are used in applications where precise, wideband pattern control is not required.

Way back in the day I believe Urie built a studio monitor around the Altec 604 coax. They ended up cutting holes in the walls of the HF horn to get it to work. I've got a paper on it somewhere that I can dig up if anyone is interested.

Something I've wondered about is whether using the woofer cone as part of the HF horn results in any funny sort of frequency/phase modulation distortion as the horn walls move a significant fraction of a wavelength when the woofer is working at high level. It appears not to be a problem in practice but I'd be interested to hear any observations on this.

I'll be looking at this driver when I next get the speaker building bug.

--Frank
Title: Re: B&C 14" coax for wedges ?
Post by: Uwe Riemer2 on February 14, 2019, 03:42:23 AM
...  No retail links coming up.  Makes me think itís not getting a lot of traction.
That is easy to explain:
The price of the 88 is 30% more than the 76, which puts it beyond the wallet of most DIY folks,
there are not many like Peter Morris.
And then you will need an amp to exploit the low/mid capabilities , for me that means 44M10, Delta 100DSP, PLM12K44
also not exactly cheap

Title: Re: B&C 14" coax for wedges ?
Post by: Helge A Bentsen on May 17, 2021, 10:05:00 AM
Old thread alert!

B&C has a design for this driver.
https://www.bcspeakers.com/media/W1siZiIsIjIwMjEvMDIvMDIvMTVfNDdfMTFfNjMyX0NYMTQucGRmIl1d
Title: Re: B&C 14" coax for wedges ?
Post by: John Halliburton on May 18, 2021, 08:54:31 AM
Old thread alert!

B&C has a design for this driver.
https://www.bcspeakers.com/media/W1siZiIsIjIwMjEvMDIvMDIvMTVfNDdfMTFfNjMyX0NYMTQucGRmIl1d

I like the polar projections, no major pinching in coverage at certain frequencies.  Some get nasty at times.

Best regards,

John
Title: Re: B&C 14" coax for wedges ?
Post by: Riley Casey on May 18, 2021, 09:16:17 AM
Yup, I'm exploring the mysteries of turning out documentation for a modified version to send to a local CNC shop to make flat pack parts for the two B&Cs I bought before the world changed.  I'm not sure their choice of 1800 hz for a crossover point isn't based more on reducing warranty clams than on the best performance at least based on my testing of the drivers. 1100 Hz low pass and 1250 high pass 4th order was the sweet spot for me.

Old thread alert!

B&C has a design for this driver.
https://www.bcspeakers.com/media/W1siZiIsIjIwMjEvMDIvMDIvMTVfNDdfMTFfNjMyX0NYMTQucGRmIl1d
Title: Re: B&C 14" coax for wedges ?
Post by: Jim McKeveny on May 18, 2021, 09:57:51 AM
I'm not sure their choice of 1800 hz for a crossover point isn't based more on reducing warranty clams than on the best performance at least based on my testing of the drivers. 1100 Hz low pass and 1250 high pass 4th order was the sweet spot for me.

Nice thing about coax's is eliminating the time alignment needs. This also makes passive crossover an option. The asymmetry in the crossover is also do-able passively. Many amps w/dsp don't allow it. Where are you headed with this?
Title: Re: B&C 14" coax for wedges ?
Post by: Helge A Bentsen on May 18, 2021, 10:30:25 AM
Yup, I'm exploring the mysteries of turning out documentation for a modified version to send to a local CNC shop to make flat pack parts for the two B&Cs I bought before the world changed.  I'm not sure their choice of 1800 hz for a crossover point isn't based more on reducing warranty clams than on the best performance at least based on my testing of the drivers. 1100 Hz low pass and 1250 high pass 4th order was the sweet spot for me.

Interesting, please keep us updated with your progress :)
Title: Re: B&C 14" coax for wedges ?
Post by: Peter Morris on May 19, 2021, 02:11:46 AM
I suspect this project is capable of producing a great result with the correct processing. Easy to see why ;-)
Title: Re: B&C 14" coax for wedges ?
Post by: John Halliburton on May 19, 2021, 08:38:13 AM
Nice thing about coax's is eliminating the time alignment needs. This also makes passive crossover an option. The asymmetry in the crossover is also do-able passively. Many amps w/dsp don't allow it. Where are you headed with this?

Agreed, the alignment is better from the start.  I've used my BMS loaded 12" coaxials for ten years now, and I've lost track of how many musicians compliment their sound.  Curtis List, RIP, designed a great passive crossover for them for my cabinet design. Here is a shot of an empty, Line-X finished cabinet. Very compact, all 18mm Baltic Birch plywood, dual Speakons, handle on one end, pole cup. All of 42lbs. when loaded with the 12N680 driver.  Mark Seaton was working on a B&C loaded version of the cabinet as well, although it's been in the background what with his regular business demands.

Best regards,

John
Title: Re: B&C 14" coax for wedges ?
Post by: Jim McKeveny on May 19, 2021, 09:05:35 AM
Curtis List, RIP,

I did not know...RIP indeed, Too Tall.
Title: Re: B&C 14" coax for wedges ?
Post by: Tim McCulloch on May 19, 2021, 09:57:59 AM
I did not know...RIP indeed, Too Tall.

Indeed.  I hadn't heard of Brother List passing.  RIP, Too Tall.
Title: Re: B&C 14" coax for wedges ?
Post by: Chris Hindle on May 19, 2021, 12:25:08 PM
Curtis List, RIP, designed a great passive crossover for them for my cabinet design.

Holy crap. When did that happen?
RIP Too Tall.
Chris.
Title: Re: B&C 14" coax for wedges ?
Post by: John Halliburton on May 19, 2021, 09:41:04 PM
Holy crap. When did that happen?
RIP Too Tall.
Chris.

July 6th last year.  As many here knew, he had some very serious health issues that put him in a wheelchair for the last years of his life.  I drove up to see him a few years ago with a pair of Magnaplanar speakers he'd found for sale by me here in Chicago.  Afraid that was the last time we saw each other in person.

A talented engineer and friend.

John

Title: Re: B&C 14" coax for wedges ?
Post by: Scott Holtzman on May 19, 2021, 10:31:11 PM
Yup, I'm exploring the mysteries of turning out documentation for a modified version to send to a local CNC shop to make flat pack parts for the two B&Cs I bought before the world changed.  I'm not sure their choice of 1800 hz for a crossover point isn't based more on reducing warranty clams than on the best performance at least based on my testing of the drivers. 1100 Hz low pass and 1250 high pass 4th order was the sweet spot for me.


14" is a very interesting sweet spot size wise.  Do you intend to sell these flat packs?  If not would extending the run for another dozen help you bring the cost down?



Title: Re: B&C 14" coax for wedges ?
Post by: John Halliburton on May 20, 2021, 08:17:49 AM

14" is a very interesting sweet spot size wise.  Do you intend to sell these flat packs?  If not would extending the run for another dozen help you bring the cost down?

Scott,

I suspect I can have the CAD files for my 12" version expanded a bit until the baffle cutout fits the 14".

Best regards,

John

Title: Re: B&C 14" coax for wedges ?
Post by: Jim McKeveny on May 20, 2021, 08:25:56 AM
14" is a very interesting sweet spot size wise.

Interesting enough that JBL had some 14 inchers over the years.
Title: Re: B&C 14" coax for wedges ?
Post by: Mal Brown on May 20, 2021, 11:30:33 AM
Old thread alert!

B&C has a design for this driver.
https://www.bcspeakers.com/media/W1siZiIsIjIwMjEvMDIvMDIvMTVfNDdfMTFfNjMyX0NYMTQucGRmIl1d

How might one go about modifying that design to make it a 40 degree horizontal box.  Array 2 for 80 with minimal boundary interference...  I have 6 old Renkus trap boxes that array really well but are too large and heavy these days...
Title: Re: B&C 14" coax for wedges ?
Post by: Art Welter on May 20, 2021, 12:00:16 PM
How might one go about modifying that design to make it a 40 degree horizontal box.
Mal,

The HF/woofer determine it's basic 80 degree conical pattern, the HF driver uses the cone as the mouth of the horn. You could extend the pattern to a lower frequency by making a cone extension "waveguide" of about 90 degrees, like the DSL SM-80. Mark Wilkinson did that with a pair of his co-ax, made the waveguides from foam core- lightweight.
Attempting  to reduce the pattern to 40 degrees would cause nasty internal reflections that would screw up the polar response more than simply stacking them. Put a pole cup both top and bottom, with a short pipe between them.
Stacking won't mess much with the horizontal pattern, but will cause some vertical lobing.
That said, you could put an  L-pad on the lower cabinet's HF, as it won't need to be as loud as the upper cabinet, which would make the vertical lobe fairly benign, especially if the lower cabinets are pointed in a bit as center fill.   

Art
Title: Re: B&C 14" coax for wedges ?
Post by: Mal Brown on May 20, 2021, 12:30:20 PM
Thanks Art. 
From that I think I can interpret that my Renkus Trap 40's are 40 only from the horn.  The front firing 15 is radiating more broadly as it is just doing what 15" cones do...

I've mixed on those boxes in splay array a long time and they seem to be almost seamless as I wander the field.  That is I don't hear the 15's interacting -which tells me I have a lot to learn...  big news there ;-)
Title: Re: B&C 14" coax for wedges ?
Post by: Art Welter on May 21, 2021, 01:32:03 PM
Thanks Art. 
From that I think I can interpret that my Renkus Trap 40's are 40 only from the horn.  The front firing 15 is radiating more broadly as it is just doing what 15" cones do...

I've mixed on those boxes in splay array a long time and they seem to be almost seamless as I wander the field.  That is I don't hear the 15's interacting -which tells me I have a lot to learn...  big news there ;-)
The side by side arc location of the 15" reduce horizontal dispersion at a frequency below the "beaming" any 15" will exhibit, as well as the "pattern flip" of the "too thin" 40 degree horn.
You could probably find polar charts for singles and multiples of your RH cabinets to get a visual idea of what you hear.

Art