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Horizontal bi-amp with different amps

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Anonymous
April 19, 2004 7:44:20 PM

Archived from groups: rec.audio.high-end (More info?)

Audio freaks,

First; pardon my ignorance in the field of high-end audio. I was
hoping someone could provide some advice/information regarding a
planned system.

A few years ago I bought a pair of KEF Reference speakers (think the
type is 3031(?), a couple of matching (passive) KEF subs (don't know
what the type is), and an amp (Onkyo, can't remember the type for
this, but I know it was about $1000-1500 at the time of purchase).

Anyway, I've started to collect a few necessities in order to upgrade
to a home theatre system; I've got hold of a REL Storm ;)  and a KEF
Reference Model 90 Centre. I'm thinking about getting a Yamaha DSP-A2
Surround Sound Amplifier and a couple of KEF sourround speakers as
well.

I'm thinking about bi-amping (horizontal(?)) the KEF References (they
are bi-wired) and use them as fronts, i.e. let the Onkyo feed the
woofer and the Yamaha mid-range/tweeters. I've read throuhg a few
discussions about bi-amping, and it seems like the amps must have
synchronized "gain" in order to provide an optimized sound quality.
I'm not sure what gain is, other than that the gain controls for my
car amps adjusts the volume. None of the amps have a specific gain
control (as far as I know). How do I go about synchronizing gain
between the amps? Is it any point in doing the bi-amp'ing at all, or
am I better off ditching the Onkyo amp?

Also, the system is (still) going to be primarily used for music
(about 80%), so I'm not sure wether to buy some "proper" speakers as
rears as opposed to specialized surround speakers. Would a pair of
e.g. KEF Coda or even Q-series be better, or will this be "too much"?
I'm not planning to set the system up in a very large room (I'm about
to start looking for a new property, so not sure about the specific
size yet).

Up till now I've been using wires you guys will categorize as
lamp-cord. In my upgraded system I'm going to spend 10% of the value
of the system on cables. Any recommendations?

Any input would be much appreciated.

Thanks,

--

Thomas

More about : horizontal amp amps

Anonymous
April 20, 2004 8:27:10 PM

Archived from groups: rec.audio.high-end (More info?)

"Thomas Muller" <ttm@online.no> wrote in message
news:c60s4k01hbl@news4.newsguy.com...
> Audio freaks,

> Up till now I've been using wires you guys will categorize as
> lamp-cord. In my upgraded system I'm going to spend 10% of the value
> of the system on cables. Any recommendations?

I'll comment only on this question. the 10% number that's bruited
about so often was originally a retrospective number, obtained by
averaging the amount spent by high-enders on wires. It's been
repeated so often that many people have the idea that they should take
10% of their expenditure and somehow find wires that cost that much.
The correct approach to all expenditures is to spend as little as
possible to get results you're happy with. And that goes for every
component, not just wires.

Norm Strong
Anonymous
May 16, 2004 6:46:53 PM

Archived from groups: rec.audio.high-end (More info?)

ttm@online.no (Thomas Muller) wrote in message news:<c60s4k01hbl@news4.newsguy.com>...

> I'm thinking about bi-amping (horizontal(?)) the KEF References (they
> are bi-wired) and use them as fronts, i.e. let the Onkyo feed the
> woofer and the Yamaha mid-range/tweeters. I've read throuhg a few
> discussions about bi-amping, and it seems like the amps must have
> synchronized "gain" in order to provide an optimized sound quality.
> I'm not sure what gain is, other than that the gain controls for my
> car amps adjusts the volume. None of the amps have a specific gain
> control (as far as I know). How do I go about synchronizing gain
> between the amps? Is it any point in doing the bi-amp'ing at all, or
> am I better off ditching the Onkyo amp?
>

I was thinking about a similar project last year... what I understand
to be the case is that you have 2 options: 1) buy an active external
crossover which would allow you to independently adjust the gain
levels of each amp as well as the crossover points for high and low
frequencies. This option would be best with amps that are hard wired
directly to the speaker drivers, bypassing the speaker crossovers: 2)
modify one of the amps (preferably the higher powered one) with a
volume pot and measure down to within a narrow margin of the output of
the first amp.

Although a potentially entertaining project, there is little or no
guarantee that your efforts will pay off with significantly better (or
even noticeably different) sound. Since either option 'done properly'
may greatly screw up the equipment, I came to the conclusion that the
risks far outweighed the benefits. I ended up selling off the extras,
investing in a really nice solid state amp, and satisfying the 'mod'
bug by vastly upgrading an albeit already nice tube preamp - its a
dead quite system and sounds great, and without the extra clutter.

> Any input would be much appreciated.

As for cables, unless your system has mega resolution (which means its
mega expensive), any well put together cable between $25 - $100 for
interconnects and $100 - $250 for speaker cable will give you as much
as you are going to get over twisted lamp cord cable in an average
'good' system. How much that could be resides somewhere between your
tympanic membrane and the depths of your brain - Its our compulsions
that drive us towards garden hose cables not our ears... but the are
very satifying compulsions to indulge, so enjoy!


> Thanks,
Related resources
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Anonymous
May 16, 2004 8:14:20 PM

Archived from groups: rec.audio.high-end (More info?)

On 16 May 2004 14:46:53 GMT, dourmaj@optonline.com (dourmaj) wrote:

>Although a potentially entertaining project, there is little or no
>guarantee that your efforts will pay off with significantly better (or
>even noticeably different) sound. Since either option 'done properly'
>may greatly screw up the equipment, I came to the conclusion that the
>risks far outweighed the benefits. I ended up selling off the extras,
>investing in a really nice solid state amp, and satisfying the 'mod'
>bug by vastly upgrading an albeit already nice tube preamp - its a
>dead quite system and sounds great, and without the extra clutter.

Agreed. Any off-th-shelf crossover, even an adjustable one, cannot
replace any eq or voicing elements in the original. Drivers are not
resistors.

Kal
Anonymous
May 17, 2004 2:11:11 AM

Archived from groups: rec.audio.high-end (More info?)

On 5/16/04 10:46 AM, in article c87ust0s75@news3.newsguy.com, "dourmaj"
<dourmaj@optonline.com> wrote:

> any well put together cable between $25 - $100 for
> interconnects and $100 - $250 for speaker cable will give you as much
> as you are going to get over twisted lamp cord cable in an average
> 'good' system.

You could relegate the cable debate to the dust bin and buy monoblocks and
make the cable length to 3' or less to the speakers! :-)
Anonymous
May 17, 2004 3:58:51 AM

Archived from groups: rec.audio.high-end (More info?)

On 5/16/04 10:46 AM, in article c87ust0s75@news3.newsguy.com, "dourmaj"
<dourmaj@optonline.com> wrote:

> I ended up selling off the extras,
> investing in a really nice solid state amp, and satisfying the 'mod'
> bug by vastly upgrading an albeit already nice tube preamp - its a
> dead quite system and sounds great, and without the extra clutter.

I would agree - but the speakers I bought can't be bi-amped - the slightly
apologetic items in the manual said that you should invest in a better
single set of cables and a good amplifier rather than several lesser ones.
Even with to ability to bi and tri amp or wire, I think the advice is good
advice.
Anonymous
May 17, 2004 4:10:02 AM

Archived from groups: rec.audio.high-end (More info?)

Kalman Rubinson kr4@nyu.edu wrote:

>On 16 May 2004 14:46:53 GMT, dourmaj@optonline.com (dourmaj) wrote:
>
>>Although a potentially entertaining project, there is little or no
>>guarantee that your efforts will pay off with significantly better (or
>>even noticeably different) sound. Since either option 'done properly'
>>may greatly screw up the equipment, I came to the conclusion that the
>>risks far outweighed the benefits. I ended up selling off the extras,
>>investing in a really nice solid state amp, and satisfying the 'mod'
>>bug by vastly upgrading an albeit already nice tube preamp - its a
>>dead quite system and sounds great, and without the extra clutter.
>
>Agreed. Any off-th-shelf crossover, even an adjustable one, cannot
>replace any eq or voicing elements in the original. Drivers are not
>resistors.
>
>Kal

IMO this idea greatly oversimplifies the issues. It is true that one should
begin the reproduction process with equipment that is as transparent as
possible but it is not true that an equalizer or other adjustment cannot "fix"
errors in process. While it might be impossible to give a woofer with
insufficient displacement true 20 Hz capability it should not be overlooked
that one CAN fix too much 100 Hz and other similar problems.

I agree that bi-amping is seldom likely to result in sonic benefit in
practically all situations but that has nothing to with whether drivers are
"resistors" and whether EQ isn't a useful tool at the acoustical end.
Anonymous
May 17, 2004 5:16:06 AM

Archived from groups: rec.audio.high-end (More info?)

What does that mean that drivers are not resistors? And would biamping
be the same waste of time as biwiring
in term of sharing the woofer duties? One last question. What exists
inside a Dali Grand Coupe as a crossover
that is being contradicted by biwiring and/or biamping? Thanks for
helping a BA understand an EE. :>)

Kalman Rubinson wrote:

> On 16 May 2004 14:46:53 GMT, dourmaj@optonline.com (dourmaj) wrote:
>
>
>>Although a potentially entertaining project, there is little or no
>>guarantee that your efforts will pay off with significantly better (or
>>even noticeably different) sound. Since either option 'done properly'
>>may greatly screw up the equipment, I came to the conclusion that the
>>risks far outweighed the benefits. I ended up selling off the extras,
>>investing in a really nice solid state amp, and satisfying the 'mod'
>>bug by vastly upgrading an albeit already nice tube preamp - its a
>>dead quite system and sounds great, and without the extra clutter.
>
>
> Agreed. Any off-th-shelf crossover, even an adjustable one, cannot
> replace any eq or voicing elements in the original. Drivers are not
> resistors.
>
> Kal
Anonymous
May 17, 2004 7:16:38 AM

Archived from groups: rec.audio.high-end (More info?)

On Mon, 17 May 2004 00:10:02 GMT, nousaine@aol.com (Nousaine) wrote:

>IMO this idea greatly oversimplifies the issues.

Of course. Intentional.

> It is true that one should
>begin the reproduction process with equipment that is as transparent as
>possible but it is not true that an equalizer or other adjustment cannot "fix"
>errors in process.

I never said anything about that, one way or the other.

>While it might be impossible to give a woofer with
>insufficient displacement true 20 Hz capability it should not be overlooked
>that one CAN fix too much 100 Hz and other similar problems.

Sure.

>I agree that bi-amping is seldom likely to result in sonic benefit in
>practically all situations but that has nothing to with whether drivers are
>"resistors" and whether EQ isn't a useful tool at the acoustical end.

No: It has to do with the fact that the crossover, active or passive,
high level or line level, must be designed specifically for the
drivers, the enclosure and the application.

Kal
May 17, 2004 7:49:51 PM

Archived from groups: rec.audio.high-end (More info?)

Kalman Rubinson wrote:
>
> No: It has to do with the fact that the crossover, active or passive,
> high level or line level, must be designed specifically for the
> drivers, the enclosure and the application.
>
> Kal

Just at the moment I'm designing an active crossover usable for a single or
double subwoofer. It is possible to compensate the lower resonance frequency
and Q and the upper frequency limit of the sub and the lower frequency limit
and Q of the satellites (by means of pluggable resistor arrays). The
crossover can be configured with a zero degree (additional)phase-shift for
the overall sound. The satellites and the sub should have closed
enclosures.
A unique feature(apart from the 0-phaseshift) is an adjustable lower pole
frequency(20Hz...60Hz) and independent Q(0.5...1). The slopes are 12dB/oct.
and symmetrical, but they overlap more. It comes in a small aluminum
enclosure(2in 4out RCA receptacles) with a wall-wart power supply. If
anyone is interested please drop me a mail. This is not a commercial project
but a favor for a few audiophile friends.
--
ciao Ban
Bordighera, Italy
Anonymous
May 17, 2004 7:52:17 PM

Archived from groups: rec.audio.high-end (More info?)

On Mon, 17 May 2004 01:16:06 GMT, Philip Meech <macmeech@adelphia.net>
wrote:

>What does that mean that drivers are not resistors?

It means that top-quality speakers often have complex crossovers which
compensate for frequency irregularities in the driver, and are much
more than simple frequency dividers such as you find in 'off the
shelf' active crossovers.

> And would biamping
>be the same waste of time as biwiring
>in term of sharing the woofer duties?

No, active biamping does indeed increase the potential dynamic rannge
if the system. Note that 'passive' biamping using the speaker
crossover does absolutely nothing.

> One last question. What exists
>inside a Dali Grand Coupe as a crossover
>that is being contradicted by biwiring and/or biamping?

You'd have to examine the response of the crossover *at the driver
terminals* to discover whether it does more than simple frequency
disvision. Biwiring is of course utterly pointless.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
Anonymous
May 22, 2004 6:38:02 PM

Archived from groups: rec.audio.high-end (More info?)

Yeah, sure, its "utterly pointless" that i heard a distinct improvement in
clarity with my Martin Logan Aerius i's bi-wired as opposed to using the cheesy
supplied metal bridge that came with it. Well, why don't we let the consumer
TRY it and decide? Afterall, its reversable. Stating that bi-wiring is
"utterly pointless" is wrong. -Bob Bernstein.
!