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View Full Version : Question on Adding a Subwoofer Newbie Here..



DjChubbzz
04-04-2012, 05:10 PM
I am presently running IDJ3 to Behringer AMP 2 Channel to 2 Large Passive JBL Speakers. Now I want to add 1 Powered SubWoofer. Is Correct that BOTH OUTS of the IDJ3 go to the Powered Sub then < back too the input of AMP, than to the JBL's... Any suggestions will be greatly appreciated, I Have not yet purchased the sub. so I have time.

DJ Riddims
04-04-2012, 06:27 PM
That is correct.

jayhwk
04-04-2012, 06:57 PM
No, it isn't correct.

The OP is trying to add a single sub, so the signal coming from his IDJ3 must be summed to mono.

Here's what I would do:

Buy two of these: http://www.amazon.com/RiteAV-RCA-Splitter-Male-Female/dp/B000V1JUJU

And one of these: http://www.fullcompass.com/product/260830.html (Or, if you have some soldering skills, build the Unbalanced Summing Box: http://www.rane.com/note109.html)

Plug the splitter cable into your mixer. Take one half of the split to the amp like usual, then take the other half to the line level summing box. Do the same with the other half. Then, take a microphone cable (cable with XLR connectors), then run it from the summing box into the subwoofer.

Here's a one-line diagram showing how to connect the pieces:

321

DjChubbzz
04-04-2012, 07:25 PM
jayhwk
First and foremost Thank you, I cant tell you how much research I have done on this and could not get an intelligent answer. You laid it out great. Thank you for your time ...........and PS Great Sketch.

Gjhowe1
04-04-2012, 07:36 PM
Depending on the sub you may not need a mono sum box, some subs can take R and L signals and sum them internally. It really depends on your sub.

My sub takes the L and R signal, sums them and sends a filtered (above 85 hz) L and R to the tops, all built into the sub.

If your getting something like a ELX-118p that only has one input then you need the setup jayhwk described.

Do some research on your sub, ask questions here.

Synaxis
04-04-2012, 07:45 PM
Buy two of these: http://www.amazon.com/RiteAV-RCA-Splitter-Male-Female/dp/B000V1JUJU


Don't Y-splitters lower impedance and deteriorate sound quality?

Wouldn't a distribution amplifier work better?

http://www.amazon.com/AV-400-Composite-Distribution-Amplifiers/dp/B000BLJE8W

windspeed36
04-04-2012, 08:25 PM
What subwoofer are you planning to use? Most active subwoofers have 2 line ins and 2 out with an inbuilt crossover so you would take the LR out of your mixer into the sub then the LR out to the amplifier.

jayhwk
04-04-2012, 08:35 PM
Don't Y-splitters lower impedance and deteriorate sound quality?

Wouldn't a distribution amplifier work better?

http://www.amazon.com/AV-400-Composite-Distribution-Amplifiers/dp/B000BLJE8W

For audio, one split should be no problem from an OUTPUT at line level. From this Rane note: http://www.rane.com/note109.html

"A wye-connector used to split a signal into two lines is being used properly"

You can't use Y-Cables to audio combine signals, which is the subject of the note.

Video has problems splitting with Y-Cables, which might be the location of the confusion.


What subwoofer are you planning to use? Most active subwoofers have 2 line ins and 2 out with an inbuilt crossover so you would take the LR out of your mixer into the sub then the LR out to the amplifier.

This is also true if the subs have built in RCA inputs. Most subs I deal with just have a single XLR input. I'd use the splitter and summing box anyway - you'll run a lot less unbalanced cable (unbalanced runs >20 feet (8m) can cause hum and buzz).

DJ Riddims
04-04-2012, 08:55 PM
No, it isn't correct.

The OP is trying to add a single sub, so the signal coming from his IDJ3 must be summed to mono.



I assumed the sub had left and right xlr inputs, most subs today have that feature.

DYM
04-04-2012, 09:14 PM
What if you get an external crossover (I use the DBX 324) which you can SET "Low Freq. Summing" Which puts your sub in mono but your tops in stereo, AND gives your frequency controls... So cables would come out of your mixer into the crossover, then from crossover to sub with one cable, crossover to amp with two cables, and then amp to tops.

jayhwk
04-04-2012, 09:21 PM
I assumed the sub had left and right xlr inputs, most subs today have that feature.

True, for some manufacturers. EV doesn't do it, and I work with Meyer speakers regularly that simply have an XLR input on the back and no other controls. I doubt the OP is looking to buy a Meyer 650-P, though. Still, I'd reccomend the mono sum to a balanced signal just to cut down on the amount of unbalanced cable.


What if you get an external crossover (I use the DBX 324) which you can SET "Low Freq. Summing" Which puts your sub in mono but your tops in stereo, AND gives your frequency controls... So cables would come out of your mixer into the crossover, then from crossover to sub with one cable, crossover to amp with two cables, and then amp to tops.

I would rate that as the most ideal solution, however, it'd cost more money. Good crossovers are a couple hundred bucks.

DYM
04-04-2012, 09:51 PM
Yea about $250 total... Here is the one I use, it's great, actually the DBX 234XS (http://www.proaudiostar.com/dbx-234xs-crossover.html)

ampnation
04-06-2012, 09:06 PM
Don't Y-splitters lower impedance and deteriorate sound quality?

Wouldn't a distribution amplifier work better?

http://www.amazon.com/AV-400-Composite-Distribution-Amplifiers/dp/B000BLJE8W

Nothing one would notice unless you're splitting a whole bunch of times. A simple 1 to 2 split... no big.

ampnation
04-06-2012, 09:13 PM
I would vote for an external crossover and put a ART DTI between the IDJ3 and the crossover to convert to balanced. The Galaxy linked to in Post 2 would work as well but I'm programmed to avoid Galaxy.