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Channel Separation?

typericey

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#1
How important is this spec?

Is it necessary to add channel separation measurements in @amirm's DAC and amp reviews?

What would be the ideal channel separation figure (dB) for a DAC or amp to be considered high fidelity?

In terms of amplifiers, does having a monoblock setup (i.e. using 1 mono amp per channel) necessarily equate to an infinitely superior channel separation performance versus a stereo amp?

The relevance of having good channel separation is only stereo imaging right? Or does good channel separation have other benefits?

Am I asking the right questions? Just eager to learn.
 

Blumlein 88

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#2
Surprisingly 20 db is enough. Cartridges used in LP are lucky to have more than 30 db with few having more than 35 db. Many cartridges only had 25 db channel separation. Yet audiophiles ooze praise of imaging in LPs. In mixing music by the time you have 20 db difference between the channels the sound has already moved over subjectively as far as it will go. I suspect that is why Amir doesn't bother with showing that test.

Yes, yes, I've heard all the hyperbole about excellent imaging and the channel separation, about mono amps etc. etc. The main benefit of mono amps is each channel having it own power supply. Another one of those audiophile myths on the need or benefits of tremendous channel separation.
 
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typericey

typericey

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Thread Starter #3
I guess channel separation is irrelevant then, because no amp or DAC is so bad to have <20dB of separation?

To be honest, part of the reason I am asking is because I'm itching to try a dual mono amp setup for the sake of experimentation just to see (hear) if there's an audible difference. I've been running integrated amps since I was a teenager. Eager and curious to try something different.
 

solderdude

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#4
For the sake of experimentation use blind tests.

When you really want to test for separation use headphones as you hear the L and R speaker with both ears drastically reducing (and frequency dependent) channel separation , not so with headphones.
In the latter case ensure it is performed using balanced outputs.
 

Blumlein 88

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#5
I guess channel separation is irrelevant then, because no amp or DAC is so bad to have <20dB of separation?

To be honest, part of the reason I am asking is because I'm itching to try a dual mono amp setup for the sake of experimentation just to see (hear) if there's an audible difference. I've been running integrated amps since I was a teenager. Eager and curious to try something different.
Essentially yes nothing is that bad. Being eager and curious to try something different is good. But channel separation isn't going to gain you anything. Even in integrated amps separation is usually 70 db or more. Often more. What speakers are you trying to power?
 

Willem

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#6
Yet another case where electronics and digital sources are not the issue. If you want to experiment with anything, the route is to avoid analogue and make sure you have a beefy power amplifier with a hefty power supply (or two). As for listening tests, yes double blind is the rule of the game.
 
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typericey

typericey

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Thread Starter #7
What speakers are you trying to power?
My primary system is a Bowers & Wilkins 705 S2 and my secondary system is a Q Acoustics 3050. Still thinking which of these I should experiment monoblocks on. I'm thinking of experimenting on a pair of Emotiva Stealth PA-1's.
 

Willem

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#8
What are the current amplifiers? If they are remotely decent I would think the biggest sonic improvement could be from adding two small subwoofers to your main system (plus Antimode 8033 dsp or similar room eq).
 

March Audio

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#9
How important is this spec?

Is it necessary to add channel separation measurements in @amirm's DAC and amp reviews?

What would be the ideal channel separation figure (dB) for a DAC or amp to be considered high fidelity?

In terms of amplifiers, does having a monoblock setup (i.e. using 1 mono amp per channel) necessarily equate to an infinitely superior channel separation performance versus a stereo amp?

The relevance of having good channel separation is only stereo imaging right? Or does good channel separation have other benefits?

Am I asking the right questions? Just eager to learn.
In addition to the info from others when listening through speakers by definition the comparatively massive channel separation of the electronics goes out the windows. You directly hear both channels in both ears :)
 

maxxevv

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#10
On a separate note, maybe I should start a different thread but does anyone have any insights as to what affects depth perception reproduction in audio devices? Assuming that all else being equal outside of the DAC and Amp used ? ( too wide a list of possibilities if room acoustics come into play).
 

daftcombo

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#11
I've read a review once, of two amps by the same brand. The 1st had 80dB channel separation, the 2nd 90dB. It was almost the only difference between them, according to the specs.
The reviewer said that the soundstage of the 1st one wasn't wide enough, but that the soundstage of the 2nd one was great.
I don't know if he said that because he tried both of them at the same SPL or because the reading of the specs made it state so.
 

Theo

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#13
Separate amps have an advantage. They can be put close to the speakers, hence allowing thinner cables between the pré-amp - DAC or what not - and the speakers area (WAF impact!) or even no cable at all as you may have wireless communication between the pre and the amps...
As far as sonic quality, I agree to what was said, no impact...
 

RayDunzl

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#14
Separate amps have an advantage.
Absolutely.

My monoblocks heat the music room more evenly than a single amp.

No more cold spots when those trickles of arctic air make their way to Tampa.

As for movies, I don't need a third heat channel, the plasma TV takes care of that nicely.
 

Kal Rubinson

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#16
I don't know if he said that because he tried both of them at the same SPL or because the reading of the specs made it state so.
We don't know if he said that because he tried both of them at the same SPL or because his reading of the specs planted the suggestion in his head.
 
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typericey

typericey

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Thread Starter #18
What puzzles me with crosstalk is how a signal from one channel leaks to the other. Sure a typical stereo amp shares the same transformer, PCB and chassis, but aren't each channel's circuits supposed to be discrete? Why can't a stereo amp be designed to eliminate crosstalk?

Apologies, I am not an electronics engineer, just an audio hobbyist. So I am not even sure if I am asking the right questions.
 

restorer-john

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#19
...Why can't a stereo amp be designed to eliminate crosstalk?...
They can be designed to make crosstalk irrelevant, but it takes careful and considered design, something seemingly lacking in a lot of modern, single board, super-compact designs these days.

CD players in the 1980s achieved >125dB crosstalk with very careful design, so it was essentially 'nailed' in the source department 30+ years ago.

Many stereo preamplifiers achieved around 90-100dB in the early 1980s, so that was deemed done and dusted too I guess.

I'm not confident many of these currently available single PCB mini components can approach similar levels. Maybe Amir can do a few L into R and R into L tests, just for fun, to see where the current gear sits. It's easy enough to shut off one input and measure the breakthrough from the driven channel into the undriven channel.
 

amirm

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#20
I actually run crosstalk tests more than I post there. Here is an example for the recently reviewed Teac AX-501:

Teac AX-501 Integrated Amplifier Crosstalk Audio Measurements.png


One of the reasons I don't post them is that for these measurements to be very accurate, they wiring from the unit to my analyzer also needs to have high isolation. I don't have that setup right now, nor have I studied how much it is impacting the results.

But yes, the larger reason was given. I don't want to crowd the reviews with more measurements unless we have some insight from them that is important.
 
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