Sub connection Question?

[Moonlight]

Hi

I had 2 Jensen subs connected through an F connector into the 1 sub input on my Denon 2105 receiver and found that one sub drew much more of the signal.
I thought this may have been due to that sub being the closer connection, so I purchased a Y adaptor which I thought would distribute evenly, but it didn't.

Just wondering whether to solve this problem, can the 2 B speaker outputs on the 7 channel receiver be used to plug in the powered subs?
If I can, is this a good idea or would I be losing a better surround sound by not having the rear speakers?


I am replacing the Denon 90w/ch 2105 with a Denon 110w/ch 3802 shortly.

Also…can the rears on the 3802 be set to 'large'..or only 'small' like the 2105?
It would be nice to have a bit of bass coming from behind if the subs are not using these channels?

Cheers

 

[j_garcia]

A sub cannot draw "more signal" on a line level connection. They are both receiving the same thing signal, regardless of the Y adapter or distance from the splitter (unless we were talking about a very long distance).

The B speaker outputs are typically full range on most receivers and are not affected by the bass management of the system so it probably isn't a good idea. As for being able to set them to large or small for the rears on the 3802, I am certain you can.

The power of your receiver doesn't affect the subs at all.

 

[MDS]

Also…can the rears on the 3802 be set to 'large'..or only 'small' like the 2105?
It would be nice to have a bit of bass coming from behind if the subs are not using these channels?

No channels can be set to Large unless the front channels are set to Large. If you set the front channels to Small so that the bass is directed to the subs (the preferred setup) then you cannot set any other channels to Large.

The subs will get any bass below the xover of any channel set to Small. So if the rears are set to Small, the subs will get any bass for those channels. But, there is rarely any substantial low frequency content in the surround or rear surround channels.

 

[j_garcia]

No channels can be set to Large unless the front channels are set to Large. If you set the front channels to Small so that the bass is directed to the subs (the preferred setup) then you cannot set any other channels to Large.

That's interesting. Is this the case specifically for the 3802 or all Denons? I am able to set speaker size independently for fronts, center, side and rear surrounds and have been able to on each of my last 4 receivers (all Marantz). I have never owned a Denon receiver.

 

[MDS]

That's interesting. Is this the case specifically for the 3802 or all Denons? I am able to set speaker size independently for fronts, center, side and rear surrounds and have been able to on each of my last 4 receivers (all Marantz). I have never owned a Denon receiver.

It certainly used to be the case with all brands but things change over time so I don't know if it's a universal rule anymore. Every Onkyo I've ever owned requires the fronts to be set to Large if you want any other channel set to Large.

 

[TLS Guy]

A sub cannot draw "more signal" on a line level connection. They are both receiving the same thing signal, regardless of the Y adapter or distance from the splitter (unless we were talking about a very long distance).

The B speaker outputs are typically full range on most receivers and are not affected by the bass management of the system so it probably isn't a good idea. As for being able to set them to large or small for the rears on the 3802, I am certain you can.

The power of your receiver doesn't affect the subs at all.

Two subs certainly will and can draw different powers form the sub output. If the subs are not the same model, then the input impedance may be different.

Say one sub has an input impedance of 10 k ohms and the other 100 K ohms. The lower impedance sub may well drop the voltage lower that the rated input sensitivity on the higher impedance sub.

It is wrong to think that a Y connector is the ultimate solution for this situation. There is no agreed standard for input impedance or voltage sensitivity. Most of the time a Y connector will work, but a purist would use zero sum buffer amps between LFE and amps as I do.

If the subs are different then he needs to buffer. If they are the same then one of the two subs likely has a problem with the input stage of the sub amp.

 

[j_garcia]

Two subs certainly will and can draw different powers form the sub output. If the subs are not the same model, then the input impedance may be different.

Say one sub has an input impedance of 10 k ohms and the other 100 K ohms. The lower impedance sub may well drop the voltage lower that the rated input sensitivity on the higher impedance sub.

It is wrong to think that a Y connector is the ultimate solution for this situation. There is no agreed standard for input impedance or voltage sensitivity. Most of the time a Y connector will work, but a purist would use zero sum buffer amps between LFE and amps as I do.

If the subs are different then he needs to buffer. If they are the same then one of the two subs likely has a problem with the input stage of the sub amp.

I was under the impression they were two of the same sub, but didn't consider that they may not be

 

[clouso]

No channels can be set to Large unless the front channels are set to Large. If you set the front channels to Small so that the bass is directed to the subs (the preferred setup) then you cannot set any other channels to Large.

The subs will get any bass below the xover of any channel set to Small. So if the rears are set to Small, the subs will get any bass for those channels. But, there is rarely any substantial low frequency content in the surround or rear surround channels.

Right...i cannot set my surrounds to large neither because my fronts are set to small!.

 

[Moonlight]

Hi
Thanks for the replies.

Both subs are the same model, yet one is considerably louder when the volumes are set to the same level. This has been the case with the Denon 2105 model which only has the one sub input, which is why I used an adaptor.

The 3802 has both L & R inputs so can I connect one into left and the other right? I take it that they are for left and right cables going into one sub only, but afaik mono is all that is required and the left rca is usually used.

If the listener had their fronts as 'small' why would they want any other speakers set to large..so it makes sense to me (not that I'm an expert as you would already know) that you cannot have surrounds as large if your fronts aren't set to large.

When I set my fronts to large on my Denon 2105, I only had the option of small for the rears.

 

[TLS Guy]

Hi
Thanks for the replies.

Both subs are the same model, yet one is considerably louder when the volumes are set to the same level. This has been the case with the Denon 2105 model which only has the one sub input, which is why I used an adaptor.

The 3802 has both L & R inputs so can I connect one into left and the other right? I take it that they are for left and right cables going into one sub only, but afaik mono is all that is required and the left rca is usually used.

If the listener had their fronts as 'small' why would they want any other speakers set to large..so it makes sense to me (not that I'm an expert as you would already know) that you cannot have surrounds as large if your fronts aren't set to large.

When I set my fronts to large on my Denon 2105, I only had the option of small for the rears.

Your correct connection is with one Y cable from your LFE out. The subs should both be connected using the left inputs on the subs. If one sub is still quieter, then it is defective.