recommended way and benefits...

[Aris A]

Hello guys...first off I need opinions from fellow members who added a sub thru their audio link to enhance bass response. I have 2 sketches attached for visuals. On the sketches, the preamp has no subout just a single output. Sub has gain & x-over to play with. Thanks for the replies if any.

 

[Tube60]

Avoid the speaker level setup if you can. Many subwoofers have speaker level ins & outs, so if you go that route, use the high pass output to your main speakers. That'll work better than what you've sketched.
Best solution is run your tube preamp's main outputs to the sub's inputs, then use the sub's high pass output (line level) to the main amplifier's input.
Technically speaking, here's why the line level setup is the best application:
By using the subwoofer's on-board crossover, you're limiting the low frequencies the main amplifier is receiving, since low frequencies would now be handled by the subwoofer, via the on-board crossover, typically adjustable by the user to best suit the equipment and the listening environment. Thus the main amplifier won't be working as hard. Speaker level ins / outs have the amplifier running unrestricted, and thus is not as efficient for many reasons.
HTH!

 

[Aris A]

Tube60,

"run your tube preamp's main outputs to the sub's inputs"
When you said "sub's inputs", you meant the line level inputs, right. I forgot to mention that it is a powered sub. Would that differ from the solution you recommended?

 

[Tube60]

Tube60,

"run your tube preamp's main outputs to the sub's inputs"
When you said "sub's inputs", you meant the line level inputs, right. I forgot to mention that it is a powered sub. Would that differ from the solution you recommended?

I went on the assumption you have a powered sub, since a passive one will only have speaker level connections. Most powered subs have the capability of both types of connections, but my emphasis is on line level connections. So to answer your question, yes, I meant the line level connections.

 

[risabet]

Actually there are differences of opinion regarding the use of speaker level inputs vs. line level inputs. One school says that the speaker level ins and outs will give the best integration between the sub and main speakers. School two says that line level ins give the most transparent sound but integration is more difficult.

Personally I like the line ins with the mains driven full range as IMS this gives the best integration and transparency. I don't run the IC from the sub to the amps because that totally F's up my transparency and sound stage (cheap x-over components I think). Try both setups and choose the one that sounds best, many people I know swear by the speaker lever setup (your diagram two), though it doesn't work for me.

 

[Aris A]

Thanks so much. That clears up everything, will try it tonight. Thanks again.

 

[amey01]

Avoid the speaker level setup if you can. Many subwoofers have speaker level ins & outs, so if you go that route, use the high pass output to your main speakers. That'll work better than what you've sketched.
Best solution is run your tube preamp's main outputs to the sub's inputs, then use the sub's high pass output (line level) to the main amplifier's input.
Technically speaking, here's why the line level setup is the best application:
By using the subwoofer's on-board crossover, you're limiting the low frequencies the main amplifier is receiving, since low frequencies would now be handled by the subwoofer, via the on-board crossover, typically adjustable by the user to best suit the equipment and the listening environment. Thus the main amplifier won't be working as hard. Speaker level ins / outs have the amplifier running unrestricted, and thus is not as efficient for many reasons.
HTH!

Personally, I have to disagree. I've found the speaker level inputs give better integration as the sub then takes on the tonal character of the main amplifier and therefore speakers. I guess it depends on the sub in question as well. In any event, try to avoid running anything through the sub - the amplifier or the speakers as this will compromise the signal by running it through an extra set of connectors and the sub itself.

How I'd do it? - run the sub and speakers directly from the main amplifier (or preamp), then adjust the sub to blend in using its crossover and level controls. I've just recently purchased a Behringer DSP1124P subwoofer equaliser and will be posting my thoughts on this shortly - am still in the process of setting it up. Good luck.

 

[Tube60]

Personally, I have to disagree. I've found the speaker level inputs give better integration as the sub then takes on the tonal character of the main amplifier and therefore speakers. I guess it depends on the sub in question as well. In any event, try to avoid running anything through the sub - the amplifier or the speakers as this will compromise the signal by running it through an extra set of connectors and the sub itself.

I agree that you disagree! I've been very fortunate in my luck with running a pass-through setup. I had an Ace powered sub, that I eventually blew up, whose crossover didn't alter the sound characteristics to any extent that I could feel or hear. That's entirely subjective in general, and can be very specific to the crossover and those who designed it, and the choices made of components. In my den I've got an MCM powered sub that I use with an ancient Trio (now Kenwood) receiver, and I'm forced to use the speaker level connections because I've got no choice. That's what I watch movies with, and it's okay, but I don't like the difficulty in getting a good blend from the main speakers to the sub, and IMO it's the speaker level setup. That of course is subjective, but my instincts are telling me this. If I had a powered sub with a remote volume control, I'd hook it up to the Record Out jacks, and I think that would work out best. However, once I have a powered sub I'm happy with, and it has a remote volume control, I'm going to try all possible connections to figure out what works best, and who knows, I might like the speaker level connections the most! However I'll probably stay with line level hookups, probably not with a pass-through connection. As a DIYer, I can play with the tonal characteristics of my gear, and I tend to make the amplifier as neutral as possible, while the preamp I'll do the most playing with to arrive at what sound I find pleasing. In that light I'd rather have the sub connected directly to the preamp.

 

[amey01]

That is exactly why we all have DIFFERENT systems and different setups. Isn't this a great hobby?