B&C 15CL76 15" Cabinet Build

[xbud]

Just for reference, I have built a few cabinets before, and they turned out pretty good, but there have been a few things I would change. Previous build project below.

1X12 Virus (Budget) Cabinet Build

Recently came accross a fire sale on a couple of B&C 15CL76 speakers and plan on building a couple cabinets this spring. They model well in WinISD and look excellent for a modular (2) 15/6 build.

Looking for some help on choosing a Crossover and a 6" Speaker for the build. The 15CL76 has high sensitivity at 98.5, would it matter much if I used an Eminence Alpha 6-CBMRA that has a sensitivity of 97.5? Also thinking of crossing this over at 1200 Hz with a 12db slope, does this sound right? Or should it be crossed over at a lower frequency? 800 Hz?

Any thoughts on the midrange would be appreciated, also thinking about swapping the 6" Speaker for a midrange tweeter and horn....any recommendations?

Any help is appreciated. Thanks!

 

[Redbrangus]

I don't know a lot about the B&C driver, but that mid driver could easily go an octave lower. Part of the concept of using a cone-type MF driver is to lower the crossover point to enable the use of a LF driver that has extended LF response and (typically) has traded that for reduced upper-range response. I don't think that B&C really fits that concept very well. It does look as if it would work well in a system with a 1200-Hz crossover point, and for that, a compression driver/horn combination is probably a better fit. All IMHO, of course.

 

[agedhorse]

It depends.

 

[xbud]

It depends.

Hey Andy, thanks for chiming in. Depends on my goals is what I am assuming from your comment?

I guess my goal would be to have something with a tight, but deeper low end frequency response. Tune to 50Hz? Controllable mids, not over bearing or harsh high end which seems like I am heading in the right direction by skipping the 3 way Crossover and tweeter.

 

[agedhorse]

Your goals, expectations, size, low frequency extension, sensitivity, power handling, etc.

 

[Marko 1]

a couple of B&C 15CL76 speakers

2x15

 

[xbud]

2x15

As much as this would work better for my needs, I need to keep the weight manageable due to back issues.

 

[Marko 1]

As much as this would work better for my needs, I need to keep the weight manageable due to back issues.

Forgive me, I have a sort of Tourette syndrome...

I blurt out “TORT” and “2x15” indiscriminately.

 

[agedhorse]

This is a fairly forgiving driver, models very well in a 3CF box with 2 x 4" dia. ports 2" deep.

Gives an F3 of 54Hz, F6 of 50Hz and an F10 of 44Hz, an average sensitivity of 98dB/1W/1M and a mechanical power handling of 500 watts RMS at 45hz which is darn good. Part of this is because of the somewhat limited LF extension but IMO this is not a negative.

Based on how this models and the mid extension, I might try running the woofer full range and crossing the 6" driver over at ~2kHz - 2.5khz (using a second order LR HP-filter alignment, remembering that the LR alignment uses -6dB to define the crossover point for constant power summing, not -3dB). I know this seems a little unconventional, but I think it will sound better.

You might first try this without the mid driver as well, with a little treble boost on the amp it may end up being ok (one benefit of a driver that doesn't support a lot of LF extension). I would be looking at a medium format tweeter crossed over at 2.5-3kHz myself, mainly because I think the driver compliments this approach pretty well.

 

[abarson]

The @Arjank Cyclops design will accept that speaker.
https://www.talkbass.com/threads/the-cyclops-a-tweeterless-115.1178086/page-2#post-17974490