B&C coaxials

Don J Davis

Sophomore
Jan 17, 2011
191
6
18
Orange County, CA
Re: B&C coaxials

Helge,
I'm a big B&C fan.
I know these aren't the same drivers or the same application you have in mind but I have two 15CXN76 and four 12FHX76 in DIY wedges and love them.
 

Don J Davis

Sophomore
Jan 17, 2011
191
6
18
Orange County, CA
Re: B&C coaxials

Can you share some details about them?

Box size, processing, power etc :)
They are ported, 1 cubic foot volume (28.75 liter?) for the 12" and 1.5 cubic foot for the 15". My monitor rack consists of 6 - Crown XTI4000's. I run the wedges bi-amped, one per amp, using the DSP in the amp. Both crossover at 1200 per the manufacture's recommendation.

IMO, the ferrite 12FHX76 sound smoother than the neo 15's but the neo's still sound good and are much lighter. They are both are 80deg nominal coverage. I like the sound of coaxial wedges. I also use JBL SRX712's for wedges and they are awesome but they lack the detail and definition of the coax (again IMO).

I also just completed a 10" coax wedge using the 10FCX64 with the B&C crossover that I intend to use for the top box of my drum fill. Haven't used it at a gig yet.

What factor has you looking at a sealed box?
 

Peter Morris

Senior
May 8, 2011
946
68
28
Australia
Jan 19, 2011
889
22
18
39
Oslo, Norway, Norway
drbentsen.no
Re: B&C coaxials

What factor has you looking at a sealed box?
I always high-pass fill/delays somewhere between 100-160hz, so I don't need that much low end. I'm thinking I don't need that extra low end a reflex design offers if I'm going to high pass it anyway.

Do you think the smoothness is related to driver size? I'm leaning towards a 12" because of the 1.2KHz crossover point. IME 15" drivers get's quite "beamy" when you get close to 1KHz.
 

Uwe Riemer

Freshman
Mar 3, 2011
93
1
8
Germany
Re: B&C coaxials

I always high-pass fill/delays somewhere between 100-160hz, so I don't need that much low end. I'm thinking I don't need that extra low end a reflex design offers if I'm going to high pass it anyway.

Do you think the smoothness is related to driver size? I'm leaning towards a 12" because of the 1.2KHz crossover point. IME 15" drivers get's quite "beamy" when you get close to 1KHz.
Can recommend the 14CXN76, the HF dispersion is much smoother than the 12CXN76 ( I own ten of these ).
My passive crossover ended a little bit more complex than the M4 crossover and still need 8 PEQs to flatten the response.

Why do you want to use the horn versions, for Fills/Delays Im pretty happy with the 80 degree dispersion of the non horn versions.

Regarding the B&C suggested design:
Has anyone checked the actual slopes of the HF crossovers.Seems pretty shallow at a quick glance ( less than 12dB/Oct ).

Uwe
 

Peter Morris

Senior
May 8, 2011
946
68
28
Australia
Re: B&C coaxials

Can recommend the 14CXN76, the HF dispersion is much smoother than the 12CXN76 ( I own ten of these ).
My passive crossover ended a little bit more complex than the M4 crossover and still need 8 PEQs to flatten the response.

Why do you want to use the horn versions, for Fills/Delays Im pretty happy with the 80 degree dispersion of the non horn versions.

Regarding the B&C suggested design:
Has anyone checked the actual slopes of the HF crossovers.Seems pretty shallow at a quick glance ( less than 12dB/Oct ).

Uwe

It’s nominally 18 dB/Oct for the HF and 12dB for the LF. (seriescap – parallel inductor – series cap for the HF) It’s also got a bit of CD horn correction and PEQ as well.
I didn’t know B&C had released the 14CXN76 … looks great, perhaps the best of both worlds (12 &15)??

FWIW Turbosound use the 12" and 15" in their TWM 112 & 115 - these designs are pre MG
 
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Uwe Riemer

Freshman
Mar 3, 2011
93
1
8
Germany
Re: B&C coaxials

It’s nominally 18 dB/Oct for the HF and 12dB for the LF. (seriescap – parallel inductor – series cap for the HF) It’s also got a bit of CD horn correction and PEQ as well.
I didn’t know B&C had released the 14CXN76 … looks great, perhaps the best of both worlds (12 &15)??
Well, it depends how you look at it.
For me it looks like series cap - parallel inductor with 4 Ohm in series - parallel resonator which acts as PEQ.

Regarding the Polarity question ( the difference between the 12 and 15" suggested design ):
Its a typo IMO

Uwe
 

Peter Morris

Senior
May 8, 2011
946
68
28
Australia
Re: B&C coaxials

Both crossovers use similar topology and jet the 15" coax HF driver is wired with polarity reversed while 12" is wired +to+. Can someone with more knowledge explain?
To see why one is positive and the other negative you probably need to model or measure everything, but it will be to do with the different phase response of the components; in particular the crossover.

The crossovers while fundamentally similar have quite different component values and as such will have different phase responses. The phase response of the 12” and 15” will also be different at the crossover point. I assume the physical time alignment between the horn and LF driver will be the same for both drivers ... but it may not be.

It’s a compromise to get the LF and HF to sum nicely, but I suspect B&C have found quite a good one.
 

Uwe Riemer

Freshman
Mar 3, 2011
93
1
8
Germany
Re: B&C coaxials

To see why one is positive and the other negative you probably need to model or measure everything, but it will be to do with the different phase response of the components; in particular the crossover.

The crossovers while fundamentally similar have quite different component values and as such will have different phase responses. The phase response of the 12” and 15” will also be different at the crossover point. I assume the physical time alignment between the horn and LF driver will be the same for both drivers ... but it may not be.

It’s a compromise to get the LF and HF to sum nicely, but I suspect B&C have found quite a good one.
After closer inspection you may be right.

What I learned from my systech work is, that manufacturers with system aproach - means speakers of the same series have very similar phase response - make my work much easier.

After finishing my design of the 14CXN crossover, I needed to redo the 12CXN crossovers to fullfill above criteria.
This is one of the benefits, if one can seperate the Phase design from the FR response design by using the DSP for the latter.

I wonder how nice the B&C suggested design ( 12" and 15" ) will play together.

Uwe
 

Riley Casey

Sophomore
Jan 12, 2011
206
8
18
WDC in the USA
www.espsound.com
Hey, lets resurrect an old thread! Not sure how I missed this thread ( especially since I commented in it ) in my searches for info on the B&C 14CXN88s. I've got one in the shop right now ( thanks Bennett ) running a little monitor wedge shoot out with my existing wedges ( I have four different brands and models in stock, time to get rational here ). I've installed the 1488 in an existing single 15 wedge on an adaptor board mainly to evaluate the mid to high performance and coverage pattern. LF performance will be addressed when I design some boxes, compared to the performance in the voice range thats a second tier consideration . Doing a round robin of filter tweeks, Smaart TF curves and listening with a variety of tracks. So far the 1488 sounds quite good. Certainly better than two out of the four wedges I'm testing against and on a par with the other two. Testing has been with a pair of Lab Gruppen IPD amps using the internal DSP all with LR 24db / oct filters. As part of my testing I've also tried some second and third order filters trying to emulate possible passive crossovers as having at least a few wedges with internal crossovers would be handy. My tests with the lower order filters thus far have not turned out nearly as well. Use, would you be interested in sharing what sort of box and passive filter design you went with?
 

Max Warasila

Graduate
Feb 20, 2013
1,131
34
48
Richmond, VA
Hey, lets resurrect an old thread! Not sure how I missed this thread ( especially since I commented in it ) in my searches for info on the B&C 14CXN88s. I've got one in the shop right now ( thanks Bennett ) running a little monitor wedge shoot out with my existing wedges ( I have four different brands and models in stock, time to get rational here ). I've installed the 1488 in an existing single 15 wedge on an adaptor board mainly to evaluate the mid to high performance and coverage pattern. LF performance will be addressed when I design some boxes, compared to the performance in the voice range thats a second tier consideration . Doing a round robin of filter tweeks, Smaart TF curves and listening with a variety of tracks. So far the 1488 sounds quite good. Certainly better than two out of the four wedges I'm testing against and on a par with the other two. Testing has been with a pair of Lab Gruppen IPD amps using the internal DSP all with LR 24db / oct filters. As part of my testing I've also tried some second and third order filters trying to emulate possible passive crossovers as having at least a few wedges with internal crossovers would be handy. My tests with the lower order filters thus far have not turned out nearly as well. Use, would you be interested in sharing what sort of box and passive filter design you went with?
Hey, Riley. I've been eyeing the 14CXN88 for a wedge design for a few years now. I'd love to compare notes and or take a listen to what you have. I'll be in town Friday and Saturday this week if you're interested.