Joining 2 channels together!

[fogg]

Hi, basically I have an amp running in bridge mode running 2 subs. At the moment I am just running the amp from the left side of the crossover. Is there anyway I can join the left and right low ouput from the crossover so that both sides drive the amp. The problem I have at the moment is anything in stereo the right side doesn't send any bass as all the bass is run by the left side (if you see what I mean!). Any ideas?!

 

Cheers Fogg

[dmoffat]

well if it's running out of the crossover from the left output, either the crossover or the desk may have some sort of mono-sum output.

As far as I'm aware there is no standard way to do this with a mono sub, and it depends on what crossover you are running and what desk.

 

Hope I can help

Dave

[fogg]

Hi there, there is no mono out on the desk or crossover. The only way I can think of doing this is to have a small mixer in the amp rack and run both left and righ sub outs into it and then taking one channel out into the amps. But this seems a bit to much to me! What I need is some kind of passive sum box but I can't find anything about on the net.

[dmoffat]

It would help to specify what crossover you are using. And it is the crossover that should do the mono sum, so it would be build into that.

 

Or you could send it out through a center/matrix/group output from the desk.

 

Dave

[fogg]

Hi there the x over is a cheap and cheerfull samson Link to x over. Desk I use is just a mix wiz 16:2, Id rather not use any of the auxes to feed the subs as I use all of them for monitor sends and effects sends. The desk does have a A-B output that could be used to run a mono send to a sub but I use this to record onto cd so would rather no go that route, also returns on the multicore are limited and would rather just be sending a L & R to the x over and amp rack.

 

Cheers

[dmoffat]

Ok well I guess the only options would either be, get a new crossover, don't run the sub amp in bridge just use it in stereo with one sub per side, or just be careful with panning.

 

 

Dave

[Doug Siddons]

YOu need a merge box like this http://www.ukgigstore.co.uk/pmbl-line-leve...e-box-163-p.asp

[fogg]

That would definately do the job but price is a wee bit steep! Well thanks for your help guys I shall have to just carry on as is and be carefull with the panning!

 

Cheers!

[johndenim]

I may have hold of the sh*tty end of the stick here, but can't it be simply, stereo desk out, crossover l+r in, crossover lf l+r into amp l+r,

amp switched to bridge mode?

 

Your amp will still see both signals, but basically merge them into one within bridge.

 

Or ar you using the right side of the crossover for something else?

[the soundman]

I Have Made a " Y " Cable One end F/XLR to Two M/XLR, That work's with No Problem I also use " Y " XLR Leads to run Two PA Rigs i.e. 2x 5000wt PA's ( Mine & a Mate's Rig)

 

Brian

[MarkPAman]

I Have Made a " Y " Cable One end F/XLR to Two M/XLR, That work's with No Problem I also use " Y " XLR Leads to run Two PA Rigs i.e. 2x 5000wt PA's ( Mine & a Mate's Rig)

 

Brian

That would be taking one output to two inputs, which is fine, and something we do every day. The OP wants to take two outputs into one input,which is different and may cause problems.

[Simon Lewis]

can't it be simply, stereo desk out, crossover l+r in, crossover lf l+r into amp l+r, amp switched to bridge mode? Your amp will still see both signals, but basically merge them into one within bridge.

 

John,

 

No it can't, since most amps "disconnect" one input side when running in bridge mode. The single input signal is commoned to both amplifiers, but is polarity inverted on one channel.

 

Brian,

 

I Have Made a " Y " Cable One end F/XLR to Two M/XLR, That work's with No Problem I also use " Y " XLR Leads to run Two PA Rigs i.e. 2x 5000wt PA's

 

That doesn't help here, as the OP wants to combine two outputs (crossover L&R) into one input. Splitting an output (as you do with your Y lead) is OK. Combining two outputs into one input is not OK. Either a transformer can be used (as shown above) or a small resistor network should be used. This can be soldered into the XLR shell.

 

Have a look at this rather useful article to see why this is a problem, and how to make a combining Y lead.

 

 

Simon

[MarkPAman]

Hi, basically I have an amp running in bridge mode running 2 subs..........

..........Any ideas?!

 

Is there any reason not to run the amp stereo? That would seem to solve the problem.

[fogg]

Going to have a good with a few resistors and see what happens with the Y lead option. It'll either work or not work so worth a try I think! Not running the amp in stereo just because I need the extra power availble in bridge mode. I am running an old c audio sr606 in bridge into 2 HK subs which have Fane colossus 15xbs in them (8 ohm). Sounds great but just wouldn't mind not having to worry about the panning problem!

 

Cheers

[KevinE]

This has been covered elsewhere in the forum recently, see Rane Audio's article as Simon says....