How to attach a sub woofer
 

I had to replace my receiver and bought another 5.1. However, the sub woofer output is only a standard L/R RCA plug and no power outlet.

The lead coming out of the speaker (RCA RT 2870) is only a single pair (purple black).

Is there a way to attach that single pair lead to the RCA terminals?

That’s strange.. usually the newer receivers have a separate subwoofer output lead that is the single pair lead. I would think there might be an adapter but can you post a pic of the back of your receiver and the speaker leads?

Which model receiver is it?

back of the Sony STR DH 590

http://forums.pelicanparts.com/uploa...1666204402.jpg

The speaker lead is a simple wire pair such as you'd use in a pinch terminal.

Does your subwoofer have a built in amplifier

I think you need an adapter like this. You would only use the top RCA jack. The bottom is if you have 2 subs.

https://www.newegg.com/p/2BY-0004-00032

It does but I don't see a power out jack for it.

Oh. You think the book would have said that. Thanks masry! (That's your hockey nick name) :D

Found this discussion from 2009. Nothing definitive though. https://www.hometheatershack.com/threads/help-with-using-an-rca-rt2870-subwoofer.23351/

With my powered sub...I found that using the sub-out connections did not allow some dvd's to pass the bass through.
I changed my wiring to connect the sub by running wires from the front main speakers to the wire terminals on the back of the subwoofer. (eliminating the sub-out wires)

Works great for all dvd's now.

Why you tricky dude. I'll keep that in mind.

Thanks hb, I did see that. Most of those threads deal with the entire RCA system. Mine is a bit of a dog's breakfast except for impedance matching.

A pic of the back of my subwoofer.
I replaced the LFE in wire with wires using the speaker inputs. (which can be done either at the speaker or the amp)

http://forums.pelicanparts.com/uploa...1666207228.jpg

Someone had to.

http://forums.pelicanparts.com/uploa...1666207350.jpg

Its complicated. Subs usually have a choice between line level input and preamp level input, like the expensive sunfire sub above. Even the cheap ones. Yours was probably part of a set, so you don't know which. The outputs of your receiver labeled sub are preamp level.
If you power a pre level input with speaker output, you might damage the preamp in the sub if it has one.
The speaker you have likely has a line level input, which means it may not produce any volume with the above adaptor-your sub out is pre level and the power would be too low. . However, if the sub input is pre level, that adaptor would work.
Safest course would be to try the adaptor and if no volume, assume the sub input is line level. Bass at sub frequency is non directional, so just drive it off of one speaker channel.

Perhaps you should plug a rca cable from the subwoofer out of the receiver into the rca input of the subwoofer.you can use one or two if you like. Bless your heart

So, split the receiver output line off of the center speaker for example?

I bought a Chronos Special Edition Blu-Ray a few years back. Playing it, I immediately noticed that my sub was not working. Tried other discs...working fine.
I was upset after paying $30 for the disc and getting no bass thru my subwoofer.

I looked closely at the print on the disc package and came up with a website for the production. At the website was a phone number...so I called.
The guy that answered the phone asked me to email a pic of the back of my sub...which is the same pic as above. He said that the rca output on my amp can't pass the digital audio encoding on some newer discs. He said "throw that cable away and run wires from the front main speakers to the audio ins on the sub."

I did that and it works great on all discs.


As an interesting side note...
He said he is an audio engineer and has worked for Alan Parsons and now works for R&B Films.

That implies that you're feeding the signal going into the Fronts back to the amp?

No...from the front main speakers to the powered subwoofer.
Just leave the original speaker wires on (the ones from the amp to the fronts)

You will end up with double wires on the front main speakers...one pair from the amp and one pair to the sub.


Amp to front main speakers to subwoofer using speaker wire

Oh. However, my amp doesn't have a power out for the subwoofer.

Don't need it...if your subwoofer is powered. (your subwoofer plugs into the wall?)

(If it doesn't....disregard all of the above...lol)

No, b/c the center for 5.1 likely is voice without bass. I'd use one of the channels, after you determine that the sub input is line.

its complicated , lol

If you give up and feel like spending money, I highly recommend the RSL Speedwoofer 10S.

One thing for certain is that with any surround sound system...the powered subwoofer is the most important part.
I have my 5.1 set-up so that it is on with all tv watching...movies, news, Jeop..all.
The subwoofer is awesome...I will never part with it.

PLUG A RCA CABLE FROM THE RECEiVER INTO THE POWERED SUB.

Good lord You boyz are turning me into nota

PS here's the manual for your receiver, pay special attention to pages 33-36.

There's no RCA jack on his sub...

The photo of the back of a sub that's above is not the OP's sub, but someone elses.

all of this talk about subs and speakers is so confusing

https://res.cloudinary.com/jerrick/i...001ebabb00.jpg

Oh whoops nevermind Sorry

So OP is saying you had the RCA receiver and 5 speaker SET, and you're replacing the broken RCA receiver but you want to use the RCA speakers and the sub doesn't have an amp, it was powered by the RCA receiver?

You will need an amp to power the rca sub or you will need a powered sub like the sun fire or similar. You can buy a crossover and feed off the main L/R as suggested but youre not gonna be very happy.

OP made a comment about "no power outlet" so I presumed the sub had a power cord, and thus its own amp...but who knows?
If all else fails, Dayton has a nice sub with pre in, line in, and adj gain and xover for under 150. I have a few of these and they're very nice for the money. https://www.parts-express.com/Dayton-Audio-SUB-1000-10-100-Watt-Powered-Subwoofer-300-628?utm_source=google&utm_medium=cpc&utm_campaign= 18197889536&utm_content=&utm_term=&gadid=&gclid=Cj 0KCQjw48OaBhDWARIsAMd966CabPo0_kqKwQQBR-Z-Ihs2GU_oNN8GvwMF8K4AidrEIMxjNWWsCxEaAvA7EALw_wcB

^^^ Nice subs....at incredible low prices!
Plus free shipping. It can't be cheap to ship a 15" sub and enclosure.

The SW does have a power cord but my new receiver has no port for it. I'm just going to fool around with running the SW off of another channel just for balance.

I did a google. I found the following which shows pics of the sub
https://www.ebay.com/itm/234696485145?hash=item36a5002919:g:ZiwAAOSwJzxjIC7 R

The back of the sub has 4 wires coming out, red/black for input, and purple black for "control" which I think is where the power comes from (via the stereo?)

I also found the following.
https://www.hometheatershack.com/att...rca-jpg.17563/

Here's another person on the 'Net trying to do the same thing. I haven't read the whole thread, but maybe they solve the problem.

https://www.hometheatershack.com/threads/help-with-using-an-rca-rt2870-subwoofer.23351/

I saw that thread and read it through. It seems that w/out the appropriate Power out port from the receiver I can't power up the SW. Matching components from other systems is just a pita.

thanks all.

Usually matching components between systems isn't hard. Usually, I believe, it's either a single pair of speaker wire and driven by the amp by speaker level inputs, or a power cord and an RCA connection with line level input and self powered/amplified.

What you're dealing with is an odd/unusual setup. I've never seen anything like it. Granted, I wasn't in the business, but I've never seen a sub that didn't fit into one of the two styles of connections that I listed above, and yours is different.

looks like a passive subwoofer that probably has the amp built into the old reciever. This is not customary. You can use something like this if you want https://www.amazon.com/Nobsound-Hi-Fi-Subwoofer-Channel-Amplifier/dp/B08D6G9CB7/ref=sr_1_2?crid=17GD5JBQU5713&keywords=subwoofer+a mplifier+home+audio&qid=1666289904&qu=eyJxc2MiOiI1 Ljc4IiwicXNhIjoiNC43NSIsInFzcCI6IjMuNjgifQ%3D%3D&s prefix=subwoofer+ampli%2Caps%2C103&sr=8-2&ufe=app_do%3Aamzn1.fos.18ed3cb5-28d5-4975-8bc7-93deae8f9840

it is a chipamp so its not really 300w but is probably plenty.


I would be more inclined to just spend a bit more on an actual decent powerd sub however:

even this super cheap monoprice unit is probably better than the rca one and would hook right up to your receiver
https://www.amazon.com/Monoprice-108248-60-Watt-Powered-Subwoofer/dp/B009GUTJ34/ref=sr_1_2?crid=348W469MZIGAF&keywords=powered+sub woofer&qid=1666290175&qu=eyJxc2MiOiI2Ljc3IiwicXNhI joiNi4wOSIsInFzcCI6IjQuNzUifQ%3D%3D&sprefix=powere d+subwoofer%2Caps%2C114&sr=8-2

people like these cheap klipsch as well which will be like 10x better than what you had I would think

https://www.amazon.com/Klipsch-Reference-R-10SW-Powered-Subwoofer/dp/B00MH42BBI/ref=sr_1_1?crid=348W469MZIGAF&keywords=powered+sub woofer&qid=1666290292&qu=eyJxc2MiOiI2Ljc3IiwicXNhI joiNi4wOSIsInFzcCI6IjQuNzUifQ%3D%3D&sprefix=powere d+subwoofer%2Caps%2C114&sr=8-1&ufe=app_do%3Aamzn1.fos.18ed3cb5-28d5-4975-8bc7-93deae8f9840

The key wording on the RT-2870 is "Home Theater Powered"
Different than a regular 'powered subwoofer'

Flatbutt, You would be better off dumping the RCA sub and getting a real powered sub that
will have an Ac cord to go to the wall and usually a RCA cable that will connect directly to your
reciever. If price is a concern go to Costco and they have a lower level Klipsh sub that will
more than likely totally out perform the RCA. Most good subs are going to be in the $350.00
to $1000.00 range. A good sub will also have a gain/volume knob on the back so you can dial
it in to seamlessly match with your other speakers. The cheap subs will not have an array of
connections on the back which limits there functionally. I've seen better subs at Goodwill than
the RCA sub you are trying to use, respectfully.