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Will Bi-amping improve SQ on low SPL ?

qguy

qguy

Super Member
Will Bi-amping improve SQ on low SPL ?

Speakers Acarian Alon IV, 3 ways with 12 inch woofers, 87dB, 3 ohms min
Amplifier: Parasound HCA 1200ii 205 wpc

This setup provides all the SPL I need, I am curious is adding a second amp to drive the tweeters and mids will help SQ.

The goal is NOT to increase SPL but to improve SQ even at low volumes
 
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Depends on how you are defining bi-amp. If you are referring to the popular passive bi-amp scheme, then I'd agree with 62caddy. If you are referring to the more "legit" format of bi-amp where you rip out the passive crossovers inside the speakers and put an active crossover unit in front of the power amps, then yes there is a good chance that the sound quality will improve regardless of the SPL you listen at. To fully realize this idea with your speakers, I'd recommend a tri-amp setup. Nothing at all between the amps and the drivers but cables.
 
qguy said:
Will Bi-amping improve SQ on low SPL ?
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Most likely not as Carl uses nice crossovers. Typically he demonstrates his speakers at shows using a single Audio Research amp.

Years ago when I heard Grand Exoticas at Sea Cliff only the sub towers used a separate amplifier.
 
The best thing, IMO and IME for outstanding performance at very low sound levels is very high sensitivity and very dynamic loudspeakers (e.g., theaterhorns, Altec Duplexes, that sort tof thing ) with low or fleapower single-ended direct-heated triode amplification. The audible quality, e.g., on a recorded track fadeout still astonishes me. It was revelatory when I first heard it,and it still amazes me.

No idea how to get there with 87 dB sensitive loudspeakers, I'm afraid. I am not sure you can, frankly.
 
mhardy6647 said:
No idea how to get there with 87 dB sensitive loudspeakers, I'm afraid. I am not sure you can, frankly.
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Naturally, Carl Marchisotto (and I) would disagree. :)

The answer is using low noise source and amplification stages. He and I both prefer those using balanced operation.

There is definitely more than one approach to using "theater horns" from the second world war for high resolution music reproduction. Our understanding and technology really have advanced since FDR was in office.
 
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Many passive crossovers have EQ networks in them to voice the speaker. Bypassing such a crossover and using an active crossover will change the intended voice of the speaker unless the EQ is taken into account. Changing the filter slope and type can change the intended voice too. I think active crossovers are best left to DIY builders or to turnkey speakers that make provision for actives.

To answer the OP: I doubt it. Especially if using that dubious practice where each leg of a passive crossover is fed a full range signal from its own amplifier and commonly known as “passive bi-amping”, a practice often known to fans of active crossovers as “fool’s bi-amping”.
 
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Tom Brennan said:
To answer the OP: I doubt it. Especially if using that dubious practice commonly known as “passive bi-amping”, a practice often known to fans of active crossovers as “fool’s bi-amping”.
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The designer of the speaker in question would most certainly disagree since he promotes using that approach. Those who have heard his designs understand the nature of who is the fool in this case.

And unlike speaker designers from the 1940s, he's still alive and can be contacted for advice!
 
E-Stat said:
The designer of the speaker in question would most certainly disagree since he promotes using that approach. Those who have heard his designs understand the nature of who is the fool in this case.

And unlike speaker designers from the 1940s, he's still alive and can be contacted for advice!
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Unless I'm missing something, the only difference is that the speaker crossover is external of the main speaker cabinet, ostensibly, to eliminate vibrations to the crossover network. Leaving the presumed virtues of that aside for the moment, it is unlike "true" multi-amplification in which active crossover processing is used from the preamplifier outputs before the signal is passed onto the amplifiers for each frequency band - which would mean the elimination of the outboard crossover. Are you suggesting the original designer would recommend that?
 
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What preamp are you using? Some preamps (and amps) are better than others at low-volume resolution. Some potentiometers have increased noise and poorer channel balance at low volumes (high attenuation). The signal goes through more of the carbon track, or more resistors, increasing noise. Magnetic (autoformer or transformer) volume controls have only wire in the signal path, and the signal goes through less wire at lower volume settings.

http://audiokarma.org/forums/index.php?threads/transformer-volume-controls.649914/

mhardy6647 said:
No idea how to get there with 87 dB sensitive loudspeakers, I'm afraid. I am not sure you can, frankly.
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Have you forgotten electrostatic speakers? ;)
 
62caddy said:
My opinion - no.
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Agree x2.

E-Stat said:
The answer is using low noise source and amplification stages. He and I both prefer those using balanced operation.
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Agree w/this ^^^^ too,,,QFT for sure...

And I tend to disagree it cant be done w/low sensitivity speakers,as I'm sure it can,just see above comment.

Heck The Canton GL-260 I'm listening to right now dont even have a listed sensitivity spec I can find anywhere,and they sound great @ low SPL.
At best I'd say they're maybe 90db,so definitely not what most would consider to be high sensitivity speakers,ask me odds are they're < 90db.
That excellent SQ @ low SPL's largely due to the NAD 106 preamp using it's XLR outs to feed an EV 7100 power amp.
The background noise (or I should say the lack there-of) of this rig is a bottomless pit of blackness.

And clean sources are important part too IMO,I feed that rig from my PC via a Parasound D/AC-1000,and what a sweet sounding DAC that is.

So really it's all about the rig as a whole if you ask me.
Some rigs just do low SPL's waaayyy better than others do.

JMO ~ FWIW

Bret P.
 
sqlsavior said:
What preamp are you using? Some preamps (and amps) are better than others at low-volume resolution. Some potentiometers have increased noise and poorer channel balance at low volumes (high attenuation). The signal goes through more of the carbon track, or more resistors, increasing noise. Magnetic (autoformer or transformer) volume controls have only wire in the signal path, and the signal goes through less wire at lower volume settings.

http://audiokarma.org/forums/index.php?threads/transformer-volume-controls.649914/

Have you forgotten electrostatic speakers? ;)
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The ESL-57s are pretty good at low low volumes, but they're not in the same league as the Duplexes. There're a pair of each here (well... two pairs of Duplexes, actually, but only one pair in enclosures).
 
qguy said:
Will Bi-amping improve SQ on low SPL ?

Speakers Acarian Alon IV, 3 ways with 12 inch woofers, 87dB, 3 ohms min
Amplifier: Parasound HCA 1200ii 205 wpc

This setup provides all the SPL I need, I am curious is adding a second amp to drive the tweeters and mids will help SQ.

The goal is NOT to increase SPL but to improve SQ even at low volumes
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No. Some speakers simply need a bit of volume to "open up", others are just fine playing flea farts.

Look at the fletcher munson curve to understand loudness and frequency perception at low listening levels. https://en.wikipedia.org/wiki/Fletcher–Munson_curves
 
Since the speaker designer/mfr is available, contact him. I wonder if the XO might have a component failure.

Also, just for shits and grins, double check your polarity. I know, it'll prolly be a triple check, but... :)
 
Get a better amplifier/preamplifier than your Parasound. And audition it at a wide range of volume settings. The best keep the sound quality over a wider range of volume. Many otherwise fine amplifiers/preamplifiers have sound which is less good unless the volume is turned up.
 
62caddy said:
You haven't answered my question.
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Ever heard of Google? Do any research yourself?

Click here for Richard Vandersteen's answer found in his FAQs. Use CTRL-F on page to locate quickly with text "bi-wiring". Some text from the explanation:

"The benefits of bi-wiring are most obvious in the midrange and treble. The low-current signal to the midrange and tweeter drivers does not have to travel on the same wire as the high-current woofer signal. The field fluctuations and signal regeneration of the high-current low-frequencies are prevented from distorting or masking the low-current high-frequencies. The back EMF (Electro-Mechanical Force) from the large woofer cannot affect the small-signal upper frequencies since they do not share the same wires.

The effects of bi-wiring are not subtle. The improvements are large enough that a bi-wire set of moderately priced cable will usually sound better than a single run of more expensive cable."

Perhaps you might send this company an email as why they offer tri-wiring on their flagship product.
 
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