Subwoofer input connections...please help!

[jazz55]

Hi! This is my first post though I've been reading as much as I can in the various forums. Great site! My issue/problem is regarding subwoofer connections. It seems I have connected my subs (2 Paradigm DSP3100) to my preamp improperly due to impatience, poor eyesight and stupidity. Currently, I have each sub connected to my preamp's SW out via a male to 2-female Y connector. At each SW, I use a female to 2-male Y connector to the L&R input. Recently, after a year of use, I re-read the sub's instruction manual and it turns out I should have used the R (mono) channel only. With the recommended configuration the bass output is audibly diminished. I do not think the SWs are damaged as I have switched back and forth and the only difference is the change in bass output. I assume that in this new configuration I can increase the bass output by manipulating the SW controls. Can someone please explain the reason for the change in output level with the different configurations? I am curious why this is so...probably a simple explanation for some, but for me, wellllll unfortunately, I am still trying to understand the ins and outs of hometheatre! Thanks so much for reading.

 

[TLS Guy]

Hi! This is my first post though I've been reading as much as I can in the various forums. Great site! My issue/problem is regarding subwoofer connections. It seems I have connected my subs (2 Paradigm DSP3100) to my preamp improperly due to impatience, poor eyesight and stupidity. Currently, I have each sub connected to my preamp's SW out via a male to 2-female Y connector. At each SW, I use a female to 2-male Y connector to the L&R input. Recently, after a year of use, I re-read the sub's instruction manual and it turns out I should have used the R (mono) channel only. With the recommended configuration the bass output is audibly diminished. I do not think the SWs are damaged as I have switched back and forth and the only difference is the change in bass output. I assume that in this new configuration I can increase the bass output by manipulating the SW controls. Can someone please explain the reason for the change in output level with the different configurations? I am curious why this is so...probably a simple explanation for some, but for me, wellllll unfortunately, I am still trying to understand the ins and outs of hometheatre! Thanks so much for reading.

What is your pre amp?

 

[jazz55]

It is an old, Classe SSP25.

 

[MDS]

Splitting the subwoofer output and feeding both the Left and Right inputs on the sub results in a +6 dB gain in voltage. The slightly higher voltage times two because you apparently have two subs wired in parallel, results in the slight increase in output.

You can use the single input and adjust the subwoofer gain up or use the current split setup and adjust the subwoofer gain down...your choice.

 

[jazz55]

Splitting the subwoofer output and feeding both the Left and Right inputs on the sub results in a +6 dB gain in voltage. The slightly higher voltage times two because you apparently have two subs wired in parallel, results in the slight increase in output.

You can use the single input and adjust the subwoofer gain up or use the current split setup and adjust the subwoofer gain down...your choice.

Thanks for the explanation. It's a relief to find out I did not screw up the subs. Now I can do more reading of the other threads.

 

[TLS Guy]

It is an old, Classe SSP25.

It is not a modern AV unit. For that you do need to connect the left output to the left sub input and the right output to the right input. Do not connect your right and left pre outs together or you will get mono. Your sub will buffer the left and right signals, so you get the bass from the left and right channels to your sub, without the whole system becoming mono.

The instructions with your sub, do not apply to an old unit like yours.

 

[jazz55]

Hi TLS Guy,
Thanks again for your reply. Perhaps my first post wasn't very clear. My preamp has only one subwoofer-out so I am using a Y splitter from the pre-out to the subs. Because each sub has a L&R input, I assumed I needed to split the signal at the sub-in, so I used another Y splitter (at the sub-in). MDS (below) replied I can leave the connection as is, or change it to the configuration in the instruction manual. His explanation seems to make sense to me, unless I misinterpreted it. With only one subwoofer-out on the Classe, do you agree with MDS? It is obvious I need to do more research on the finer points of subwoofer connections.

 

[TLS Guy]

Hi TLS Guy,
Thanks again for your reply. Perhaps my first post wasn't very clear. My preamp has only one subwoofer-out so I am using a Y splitter from the pre-out to the subs. Because each sub has a L&R input, I assumed I needed to split the signal at the sub-in, so I used another Y splitter (at the sub-in). MDS (below) replied I can leave the connection as is, or change it to the configuration in the instruction manual. His explanation seems to make sense to me, unless I misinterpreted it. With only one subwoofer-out on the Classe, do you agree with MDS? It is obvious I need to do more research on the finer points of subwoofer connections.

You can connect it either way. Most older preamps had right and left sub outs. Yours is unusual.

 

[jazz55]

Thanks for the confirmation!