How to attach a sub woofer

flatbutt · 10-19-2022, 08:28 AM

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?

rattlsnak · rattlsnak's Garage

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?

flipper35 · flipper35's Garage

Which model receiver is it?

flatbutt · 10-19-2022, 10:33 AM

back of the Sony STR DH 590

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

Gogar · 10-19-2022, 10:43 AM

Does your subwoofer have a built in amplifier

masraum · 10-19-2022, 10:49 AM

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

flatbutt · 10-19-2022, 10:50 AM

Quote:

Originally Posted by Gogar

Does your subwoofer have a built in amplifier

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

flatbutt · 10-19-2022, 11:04 AM

Quote:

Originally Posted by masraum

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

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

hbueno · hbueno's Garage

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

stevej37 · 10-19-2022, 11:08 AM

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.

flatbutt · 10-19-2022, 11:19 AM

Quote:

Originally Posted by stevej37

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.

flatbutt · 10-19-2022, 11:20 AM

Quote:

Originally Posted by hbueno

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

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.

stevej37 · 10-19-2022, 11:21 AM

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)

Bill Douglas · 10-19-2022, 11:23 AM

Someone had to.

greglepore · 10-19-2022, 02:32 PM

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.

Gogar · 10-19-2022, 02:50 PM

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

flatbutt · 10-19-2022, 02:51 PM

Quote:

Originally Posted by greglepore

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.

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

stevej37 · 10-19-2022, 03:10 PM

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.

flatbutt · 10-19-2022, 03:13 PM

Quote:

Originally Posted by stevej37

. 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."

.

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

stevej37 · 03:26 PM

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