Add a subwoofer output to a 2 channel amp? NEWB ALERT!

[kenrhodes]

I have 2 old school 2 channel amplifiers in my man cave and neither of them have a subwoofer output. They both have pre-outs but nothing else. I could swap a bottom of the line Sony 5.1 in their but that is a step back in quality.
What I wish I could do is add a subwoofer out but I don't have a clue where to start. I have never seen a mini dsp and all of the crossover networks I could but are not adjustable untill you spend a lot of money.
I looked into adding a sound card and that seems like a lot of cables and adapters just to get a sub out.
Thanks for helping on such a boring question.

[DannyG]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

You can use a RCA jack splitter two go back to pre-amp in on your amp,the other two go to a sub amp with you would need with a 5.1 receiver anyway.The only other way I can think of would be through a sub x-over board and then into the other amp but that would be fixed at about 130hz.

[NickS]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

You could use a 2 way crossover like this : http://www.parts-express.com/pe/show...umber=245-1182

[Chris Roemer]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

Not exactly sure what you're shooting for there, but MY sub is running off pre-outs. One set to the sub, the other set back to the power amp. No filtering, but the sub tracks the volume control, and it's got its own LP filter (on the plate amp). Circa 1972.

Also, if I DIDN'T have a pair of pre-outs, I'm pretty sure I could daisy the power amp off the plate amp's line out.

[DannyG]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

If you traded one amp for a receiver that had LFE you could use the other amp to power your sub since LFE receiver has low pass controls.

[Mark65]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

Or, you could use the high level inputs that are on most plate amps. Run the speaker outs to the plate amp high level ins, and the plate amp outs to the speakers.

Easy peasy.


Mark

[DannyG]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

I think he wanted to power a sub without having to buy a plate amp

[DannyG]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

I think the best way without buying a plate amp would be PE #260-221.You can run your speaker output strait through it then it has outputs that go to your main speakers high passed and to your sub low passed and is rated at 200 watt rms power handling.

[kenrhodes]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

Wow, I left out some important details about the amp I am using for my subwoofer it is a P.A. amp that does not have a LP filter on it.
The Rolls SX21 that was linked would work but that is almost the price of a good used 2 channel receiver that would have a sub out.

Would this work?http://www.parts-express.com/pe/show...number=266-444 even though it is not adjustable it should work.
Since the pa amp is only doing low frequency should I filter it on the input side instead?

[DannyG]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

That would only low pass one channel I believe so you would need two and a dual voice coil sub.Did you check out #260-221 on page 166 in the catalog.

[bkeane1259]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

How about a Fmod?

http://www.parts-express.com/pe/showdetl.cfm?partnumber=266-252

[AJ]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

You could use a Behringer CX2310. It's a basic pro audio two way crossover. They can be had for $40-$50 on ebay.

[DannyG]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

Input low pass or output low pass will both work but you will need a dual voice coil sub,do you have a sub already

[pnoneal...]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

The Crown XLS series had HP and LP 4th order filters. Just get one of those and put the LFE from your receiver or AVR and put a HP filter on the Crown as a HP filter. Since the LFE has all bass I use a 20 Hz HP filter to help cone excursion issues. I think Harma Kardon sells a 2.1 receiver with LFE out IiRC.

Paul

[stan]

Re: Add a subwoofer output to a 2 channel amp? NEWB ALERT!

Just use a pair of RCA splitter "Y" cables, with one leg going back into the old school amp input, and the other leg going into an inexpensive car audio subwoofer crossover like this http://www.allaudioexpo.com/nav/deta...=110&tran=fgle Power the car audio xo with a 12 vdc wallwart, you probably have one laying around. The output from the car xo goes into the input of the amp you want to use as your sub amp.