On 7 Feb 2003 00:32:43 -0800, geneticallymutant@hotmail.com (JBorg, Jr.) wrote:

>> d_ruether@hotmail.com (Neuman - Ruether) wrote in message

>> >(JBorg, Jr.) wrote:

[...]

>> >I'm just gonna have to disagree here Neil. Having the Y connector

>> >betw preamp and pwr amp, which is my current set-up, has its disadvantages.

>> >Without the Y connectors, images are sharper and much more palpable.

>> >There are many more but these are the first things that I would notice-

>> >as I have switch back n forth with n without the Y's many times before.

>> [...........]

>> I used to design, build, and sell LARGE subwoofers

>> (ones that really did what the others only promised ;-).

>> See: http://www.David-Ruether-Photography.com/Audio.html.

>> Some comments:

[....]

>> - If you "Y" off either the tape out (no volume/tone

>> control) or off the preamp line out and directly

>> combine one set of outputs to feed a mono subwoofer,

>> you will force the preamp channels to mono (and this

>> can damage the preamp, depending on its design).

>Wow! good info. Yes, I think the output sig. from preamp

>is never really meant to be split with Y to connect to

>a single subw system. I just took those Y splitters just

>now and plugged the subw to the preamp's tape out. I

>notice a better stereo separations on the main speakers

>right away.

Then the tape-outs must have larger protective resistors

in series than the line-level output does - but tying the

channels together without suitable series resistors on

each channel will likely reduce stereo separation

noticeably. These are easy to add...

>> - If there is a series resistor before the outputs

>> of the preamp, and/or at the sub (stereo) inputs,

>> the size of the resistor will determine the amount

>> of stereo lost with the connections (but even fairly

>> small values may protect the preamp).

>Ok.

>> - You can add resistors to the legs of the "Y" adapters

>> that go to the subwoofer (try 5k on each to start).

>> - If there are ANY electronics within the sub box in

>> series with the preamp-amp connectors (even a single

>> high-quality capacitor in series with the power

>> amp), the sound of the main speakers with the sub

>> turned off will change - generally for the worse

>> (even with a big enough cap to start cutting response

>> well below the speakers lower limit, even if the cap

>> is paralleled with small high-quality caps to improve

>> their high-end response...), so with very detailed

>> speakers (many electrostatics are), you can easily

>> hear the effect of the series electronics and may want

>> to avoid them.

>Thanks, I really do not wanna go this route anyway.

>I would probably just replace the preamp with one having

>(2) subw output. I heard it's better to use two identical

>subw.

Yes, this is true - but you can make a simple dual-mono

output with the needed series resistors very easily, and

still use a mono subwoofer...

>> - Sub placement is critical, though good sub output is

>> omnidirectional. Poor placement can result in very

>> uneven response and can also spoil directional info of

>> well-placed high-quality main speakers.

[...]

>> - With my sub designs, I used two methods of crossing

>> over between the sub and the main speakers: the common

>> one of building a high-quality 12db/octave low-cut

>> pair for the main speakers, combined with a soft-edged

>> 24db/octave summing/EQing/level-control crossover for

>> the sub (works well for most systems); or, a direct

>> connection of the preamp line out with the main-speaker

>> amps inputs (no crossover for these - they roll off

>> by themselves, which is why the sub is desired...;-),

>> with an adjustable angle 36db-ultimate, soft-corner-

>> start EQ/response-rotate/level-adjust "crossover" for

>> the bass, which permits blending of the sub into the

>> main speaker output without electronically disturbing

>> them.

>Sounds interesting. A subw outputs from pwr amps!

??????

No - the outputs are at line level and they parallel

the outputs to the main amps. These feed the EQing

device that feeds the subwoofer amp (and speaker),

matching up their response to blend in with the

already LF-rolled-off-on-their-own main speakers...

>> - Even with this arrangement, subtle shifts in the sub

>> output-level/response-shape can effect the audio balance

>> all the way to the highest frequencies of the main

>> speakers (I never came up with a good explanation for

>> this...), so the adjustment must be done with great

>> care (this can take several days to get it right - but

>> when you do, the original excellent sound has the

>> benefits of the addition of the lower frequencies).

>> - Done right, a sub adds subjectively higher sound

>> levels to the same levels previously used, adds

>> "solidity" and "excitement" without "boom" or

>> "bluddle-luddle" effects, and even the background

>> "air" of recordings with little real bass sounds

>> better-balanced. And, a good sub set-up NEVER makes

>> you aware of the sub as a sound source...

>> - Done wrong, adding a sub is worse than not...

>> David Ruether

>Thanks for the infos. and the website.

REAL bass can be FUN!!! ;-)