What happens to preamp output using "Y" adapters?

[Daddy Dee]

I'd like to use a preamp line out to power a subwoofer, but only have only a L and R output on my preamp.

If I use "Y" adapters to get additional line outs sending one pair to the power amp and the other to the sub... what happens to the signal. Any downside to doing this?

Thanks in advance for any help here.

[Q-Man]

No down side, it will work fine.

[michael hurd]

The voltage produced by the preamp, will be the same as what each component gets. If you think of a lighting system, no matter if you hook up 3 light bulbs in parallel, they each receive the same voltage. As long as the input impedance is high enough on both the amplifier, and the subwoofer, you won't have any problems. Most modern amplifiers typically have a large enough input impedance, to allow running two or more off of one output source.

I have run 3 power amplifiers off of one mixer, without any problems at all for several years.

[Daddy Dee]

Thanks guys.

[D-MAN]

I always thought that the impedance would be adversely effected, and the result less satisfactory than a single connect.

But the guys say otherwise, so I bow to first hand experience over my theory...

DM

[Q-Man]

D-Man,

Your thinking about adding speakers or speaker wire from an amp. Here impedance will change depending if you wire the additional speakers in series or parallel.

Pre amp outputs or pre-outs on a receiver are line level and the best way to add speakers or channels. But, you need another amp.

I split my rear channels from the pre-outs then to another amp so I can have 4

rear surrounds. I am also going to split my main channel outputs and send one pair to my main channel amp and the other to a separate processor then to an amp for front effect channels like the higher end Yamaha receivers. I'm experimenting with this now while I search for a AV/pre-amp controller. I'm leaning towards an Anthem right now.

[D-MAN]

Q-man, well, uh, no - I was thinking about the impedance of the pre-outs... (although apparently badly)

But I don't have any experience there, I was confused by the IN side of things on the PREAMP where impedance does matter.

As always, thanks,

DM

[Q-Man]

You know what they say when you assume something. I guess I did it again.

[DrWho]

well technically, splitting the output with the y-adapters does affect the impedance that the two seperate amps are seeing...it's just that this difference doesn't usually become an issue until you've split the signal 8 or 16 ways (depends on the individual impedances). but by the time you've got that many splits, there are probably better ways of routing the signal. that said, there should never be an issue using y-adapters to split the source as long as you're not being crazy.

[dubai2000]

Dee,

you way of connecting a sub was exactly what I was doing until recently. Then it was pointed out in another thread that it might be advantageous to use the sub's inbuilt crossover to separate bass frequencies (in my case below 70hz) from the rest which is then fed into the main amp. I was told that like this the amp might perform a bit 'better' as it has been relieved of some of it's work.

Well, I tried this way of connecting the sub and found bass performance superior. It seems to be more focused, so try sending the signal from your preamp to the sub and then to your power amp. You might actually like what you hear .

Wolfram

[garymd]

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On 6/28/2004 9:35:12 AM dubai2000 wrote:

Dee,

you way of connecting a sub was exactly what I was doing until recently. Then it was pointed out in another thread that it might be advantageous to use the sub's inbuilt crossover to separate bass frequencies (in my case below 70hz) from the rest which is then fed into the main amp. I was told that like this the amp might perform a bit 'better' as it has been relieved of some of it's work.

Well, I tried this way of connecting the sub and found bass performance superior. It seems to be more focused, so try sending the signal from your preamp to the sub and then to your power amp. You might actually like what you hear

.

Wolfram

----------------

Wolfram,

I don't quite understand what you're saying. I was planning to eventually try out my RSW12 with my MkIIIs and Blueberry using Y-Adaptors. Can you explain exactly how to hook it up using the inbuilt crossover of the RSW12?

Thanks. I'm a little confused.

[dougdrake]

Wolfram - Interesting. I thought a sub amp's cross-over only worked on high-level (speaker-level) inputs, not on the line inputs...DD

[Colin]

I have tried using the loudspeaker outputs on my KSW sub, which sends only mid and lower bass to the subwoofers and everything else to the satellites (in this case, super-sensitive walnut-oiled Cornwall 1s, with B2 crossovers). I did NOT like the sound, even though something like only 40Hz and below was missing from the Corns, the sub seem to mess up the clarity of the mid-range. Instead, I sometimes (I am always changing configurations due to my EnjoyTheMusic.com reviews) split the signal from the pre-amplifier outputs to the subwoofers and send full signals to both satellites and subwoofers.

[dubai2000]

Sorry for being unclear. My current (and preferred) sub connection is as follows: Preamp out....sub in (using what SVS calls low level input - i.e. not the speaker input)...sub out to poweramp.

Before I used a Y-adapter from the preamp (i.e. running a full signal parallel from pream to sub and power amp). With my former REL sub I hooked it up parallel to the power amp's speaker signals.

Of all those connections I like the one mentioned first best. As written before, the bass seems to be a bit more controlled and mids seem actually a bit clearer. Okay, I am not talking about huge differences, but to my ears they were/are discernable.....and I am not only talking about my 1.5 watts OTL amp, but tried it first on my MC30s. I might also add that first I was reluctant to put the sub (ss amp) between my tube amps, but I really cannot report anything negative...but remember: according to my ears.

Wolfram

[Mitch Lee]

Yes, I have spit signals this way with no audible effect. I think the problem may come in if one reverses the process and Ys two outputs together to get a mono mixed center channel or subwoofer output. In this case my experience is that bad things happen like all the signals going to mono or the circuits becoming unstable, noisey, or cancelling each other. So in that case one would need some resistors to keep the R and L preamp outputs from seeing each other. But I have also done this with resistors in place and its seems to work fine.the details for this are all over the web.

 

[OO1]

7 minutes ago, Mitch Lee said:

Yes, I have spit signals this way with no audible effect. I think the problem may come in if one reverses the process and Ys two outputs together to get a mono mixed center channel or subwoofer output. In this case my experience is that bad things happen like all the signals going to mono or the circuits becoming unstable, noisey, or cancelling each other. So in that case one would need some resistors to keep the R and L preamp outputs from seeing each other. But I have also done this with resistors in place and its seems to work fine.the details for this are all over the web.

 

pictures , we need pictures 

[wuzzzer]

15 minutes ago, Mitch Lee said:

Yes, I have spit signals this way with no audible effect. I think the problem may come in if one reverses the process and Ys two outputs together to get a mono mixed center channel or subwoofer output. In this case my experience is that bad things happen like all the signals going to mono or the circuits becoming unstable, noisey, or cancelling each other. So in that case one would need some resistors to keep the R and L preamp outputs from seeing each other. But I have also done this with resistors in place and its seems to work fine.the details for this are all over the web.

 

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