Connecting Receiver to Logitech Subwoofer

[JamesHenry]

Hey guys, 

Have a Denon receiver, and Logitech Z-906 speakers. I'm trying to bypass the dac/amp in the sub woofer. 

I hooked up all the speakers to the receiver, and they work perfectly. But I'm at a loss as to how I should connect the subwoofer. There's a pre-amp out on the receiver, but with a single out slot, and the only appropriate "in" in the sub is rca (l/r red white cable). Can't find the proper cable.

So far, I've tried with a S/PDIF cable from the receiver to two different subs (one had a single in, the logitech I plugged into one of the two RCA entrances) Neither of them produced any sound. (one of them might be dead, the logitech works 100%) Any suggestions on how to hook this up properly. 

[Norwegiantweaker]

you "cant". you could probably try sub signal cable to jack and use the black input. but i dont think its gonna work .

[Lauen]

theoretically a mono RCA to 3.5mm jack should work, but I can't find any info from Logitech on which input on the sub is for center + sub. you could get one of those cables, plug from sub preamp output and then just try all 3 inputs on the sub one after another until you get something. I can't guarantee you WILL get something because prepackaged cheap surround systems don't always work well in a DIY setting. you can probably get one of those cables I linked for like 5 bucks so it won't be a too expensive way to test it out. 

 

personally I'd get a standalone sub, for example this bestseller on amazon (maybe not a great one but certainly pretty nice value) or from a decent brand with a very simple setup with just power, volume, and a single mono RCA connector.

[Danioki]

i have something similar and connected the pre sub to the left input, in your case it the left or right of the input 2.

 

another alternative is to connect from any output to the L-R input, or optical if you have, and then remove the low frequency cutoff from the receiver and do the cutoff in the subwoofer.

[ShearMe]

I don't think you can bypass the amplifier in the subwoofer with the built-in connectors, but that shouldn't matter. Connect the "pre-out" black RCA to either of the L/R RCA inputs on the amplifier. If you're not connecting the satellite speakers to the sub, having only one RCA connected wont make a difference.

 

The pre-out port bybasses the reciever's amp, and is specifically intended for subwoofers. They do this because they know the little amp they shove into the reciever will be underpowered for anyone wanting to add a subwoofer! 

[JamesHenry]

Thanks! I've tried a bunch of those solutions. So far the best I can do is use the receiver out and connect it to the subwoofer in, via RCA. It works if I turn on the logitech console. But I'm wondering whether the pre-amp out makes any difference for a normal out?

In any case, it works fine for now. Thank you for all the answers :)

[Norwegiantweaker]

8 hours ago, JamesHenry said:

Thanks! I've tried a bunch of those solutions. So far the best I can do is use the receiver out and connect it to the subwoofer in, via RCA. It works if I turn on the logitech console. But I'm wondering whether the pre-amp out makes any difference for a normal out?

In any case, it works fine for now. Thank you for all the answers

what you could do ( better off selling the logi system) is you could remove the screws for the sub housing and remove the cables to the built in sub and get a dedicated mono to hook up to ur system and power the sob that way. to be pair tho i would either use the logi as a music sys somewhere else get some quality JBL's or any other brand for that matter and a dedicated sub that allows you to natively hook up a sub signal cable. i have the same system you are asking about and its "OK" unless you want something that actually punches the music boxes.. ( have not tried to hook it up to a different receiver but i don't think it will push much more than natively) 

[jedylan]

I know this post is old, but I am wondering how well it worked?

I am thinking of buying a new 5.1 system + 9.2 receiver.

But I don't want to just throw out my logitech kit or even sell it at a stupidly low price.

So I would use the 4 logitech speakers as my 4 height speakers and use the Subwoofer as a 2nd sub.
I am not worried for the speakers, and I am sure its going to work for the sub I'm just not sure how best to make it work.

[ShearMe]

16 hours ago, jedylan said:

I know this post is old, but I am wondering how well it worked?

I am thinking of buying a new 5.1 system + 9.2 receiver.

But I don't want to just throw out my logitech kit or even sell it at a stupidly low price.

So I would use the 4 logitech speakers as my 4 height speakers and use the Subwoofer as a 2nd sub.
I am not worried for the speakers, and I am sure its going to work for the sub I'm just not sure how best to make it work.

I would avoid using the Logitech as a 2nd subwoofer. It probably will match poorly with your newer kit.

Can definitely use the satellites as height channels, however. Should be able to set them up on the receiver as "small" or "medium" speakers and tune their levels separately. Get some RCA to banana plug adapters if you don't want to cut and strip the existing connections: https://www.amazon.com/CESS-023-6i-Speaker-Banana-Adapter-Receiver/dp/B07SQB7BD3/

[Skip]

I agree that the Logitech sub will sound bad next to real audio gear. You will get raped selling the Logitech speaker set, so why not put them on another system? It would also make a great gift to a struggling friend or relative. Compared to cheap headphones, that Logitech system will sound gorgeous.