Please help wiring BFM Omni 15

faviobarrio · #1 10-08-2011, 12:50 PM

Would someone mind helping me?

From the BFM directions for the Omni 15 cab I've figured out which crossover is which, but I can't figure out quite how to wire it and the photo is not very clear.

So from the jack there's going to be one set of 1" wires to which the other connections will be made.

From that 1" wire there will be one length of speaker wire going to the band pass filter IN+ and one to the ground. Another set of speaker wires from the band pass filter's out W+ and one to the ground and these go to the mid range driver.

From another solder point from the 1" wires on the jack, there be one length of speaker wire going to the low pass filter IN+ and one to the ground. Another set of speaker wires from the low pass filter's out W+ and one to the ground and these go to the 15" driver.

The drivers are each connected to their respective filters then to the jack but not to each other.

Is this right? I don't want to screw this up and I've never wired cabs with crossovers or even with multiple drivers in them. And, as I said I'm just not completely getting it from the directions and the photo isn't clear enough for me to make it out.

BTW, I haven't been cleared yet for posting on BFM's site. Thanks.

cheapbasslovin · #2 10-08-2011, 05:38 PM

This sounds about right.

It sounds like you aren't putting in a high frequency section, is that right? Just a sub and mids section?

Personally I like to make my taps (tap= splice = split etc.) on fixed terminals like the input jack or a terminal block mounted in your speaker. What you are planning isn't wrong electrically, though, and if properly fastened and insulated shouldn't be a problem.

You can splice all the grounds together in the easiest place to get them to. Then just bring one back to the input jack if you find that simpler than running a pair to every location. If this paragraph confused you then ignore it and go with your original plan.

Good luck.

billfitzmaurice · #3 10-08-2011, 05:43 PM

Quote:

Originally Posted by faviobarrio

So from the jack there's going to be one set of 1" wires to which the other connections will be made.

From that 1" wire there will be one length of speaker wire going to the band pass filter IN+ and one to the ground. Another set of speaker wires from the band pass filter's out W+ and one to the ground and these go to the mid range driver.

From another solder point from the 1" wires on the jack, there be one length of speaker wire going to the low pass filter IN+ and one to the ground. Another set of speaker wires from the low pass filter's out W+ and one to the ground and these go to the 15" driver.

The drivers are each connected to their respective filters then to the jack but not to each other.

Is this right?

Correct.

faviobarrio · #4 10-08-2011, 06:00 PM

Thanks for the help. I was almost done wiring it that way so it was good to hear it was going to be OK. Be done soon...can't wait to finally hear this thing!!!

faviobarrio · #5 10-08-2011, 06:41 PM

Well I did something wrong. Mid driver works but no woofer...go back and check the connections. :-(

faviobarrio · #6 10-08-2011, 07:10 PM

Well I rechecked my connections and the woofer still doesn't work. Only thing I can think of is if I connected the band pass filter to the woofer and the low pass filter to the mid driver. That would make the woofer silent right?

I bought the crossover pre-built from Leland Crooks so I know that should be OK but the two filters didn't come labeled. But according to the diagram, the filter with the 20uf capacitor is the one that gets connected to the woofer right?

I've got to quit today, have a beer and relax. I'll come back to this tomorrow and re-wire everything from scratch. This sucks.

:-(

billfitzmaurice · #7 10-08-2011, 08:40 PM

There is no 20uF capacitor in the Omni 15 low pass filter. Even if you connected the woofer to the wrong filter it would still work, it just wouldn't work in the lows.

faviobarrio · #8 10-08-2011, 08:42 PM

I have an old version of the Omni plans, the one that uses the Alpha for the mid driver.

billfitzmaurice · #9 10-08-2011, 08:44 PM

Quote:

Originally Posted by faviobarrio

I have an old version of the Omni plans, the one that uses the Alpha for the mid driver.

It makes no difference. You'd still hear mids though the woofer.

faviobarrio · #10 10-08-2011, 08:52 PM

Quote:

Originally Posted by billfitzmaurice

There is no 20uF capacitor in the Omni 15 low pass filter. Even if you connected the woofer to the wrong filter it would still work, it just wouldn't work in the lows.

OK, so I guess my woofer is bad.

But, the filer in the attached diagram from the Omni 15 plan that I am working off, has the 20uF capacitor and it is connected to the woofer right?

billfitzmaurice · #11 10-08-2011, 09:00 PM

Quote:

Originally Posted by faviobarrio

OK, so I guess my woofer is bad.

But, the filer in the attached diagram from the Omni 15 plan that I am working off, has the 20uF capacitor and it is connected to the woofer right?

Right, though that was superceded nearly a year ago.
Test the woofer with no filter to see if it works.

faviobarrio · #12 10-08-2011, 09:09 PM

Yes, Leland told me the plan was old. I had just bought the plans for the Jack 15 but then I bought a prebuilt Omni 15 unloaded and unfinished so i went with that. Then I had already bought the Alpha when Leland realized I was working off an old plan.

Thanks for your help Bill. I'm glad I at least originally wired it right even if the woofer didn't work. I will test it straight tomorrow.

faviobarrio · #13 10-09-2011, 04:08 PM

Update:

So today I re-wired everything from scratch. Plugged it in before sealing the back of the cab to make sure that both drivers were producing sound...and yes, both we're working...for about ten seconds. That loud scratching from the mid driver, then electrical burning smell from the mid driver, then no more sound from the mid driver.

Back to the drawing board. I guess that driver is shot now.

billfitzmaurice · #14 10-09-2011, 06:50 PM

Quote:

Originally Posted by faviobarrio

That loud scratching from the mid driver, then electrical burning smell from the mid driver, then no more sound from the mid driver.
.

That would happen if you ran it with the wrong filter, an improperly wired filter, or with too much power with no filter.

faviobarrio · #15 10-10-2011, 10:45 AM

Got it all sorted. Ordered a new mid driver. Thanks again for your help.

SBsoundguy · #16 10-10-2011, 12:13 PM

It's a good thing those Alphas aren't too expensive.