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post #676 of 1671
no
post #677 of 1671
It seems my business partner will be the last person to ever be convinced of what I can do with digital filters, insisting that getting it done using hardware is different. As far as I know, for perfect audio you just need to take care of frequency response, phase response and distortion--and good distortion figures can be had from cheap gear while frequency response and phase response can be taken care of by digital filters. But whenever I debate the topic with him he brings up a jungle of audiophile jargon, none of which I believe is relevant to the point, but I can't seem to prove that to him without acquiring a double PhD in acoustics and public speaking rolleyes.gif Help?
post #678 of 1671
Quote:
Originally Posted by Joe Bloggs View Post

It seems my business partner will be the last person to ever be convinced of what I can do with digital filters, insisting that getting it done using hardware is different. As far as I know, for perfect audio you just need to take care of frequency response, phase response and distortion--and good distortion figures can be had from cheap gear while frequency response and phase response can be taken care of by digital filters. But whenever I debate the topic with him he brings up a jungle of audiophile jargon, none of which I believe is relevant to the point, but I can't seem to prove that to him without acquiring a double PhD in acoustics and public speaking rolleyes.gif Help?


Well, there is always the blind test of some sort.  Can he tell a difference or is it all just bias in his mind?

post #679 of 1671
How do you blind test IEMs?

Well, there's a slew of CIEM demos coming our way, all with the same shape. Hmm cool.gif

What I'd love to have is some sort of reductive reasoning with scientific backing proving that frequency response, phase response and distortion are all we need to look at.
Edited by Joe Bloggs - 4/23/14 at 2:32am
post #680 of 1671
Quote:
Originally Posted by SilverEars View Post
 

I was at RWA's website checking out the Isabella Amp.  http://redwineaudio.com/components/isabella-re

 

And something perplexing I've run into.  This amp is run on a battery to elimate AC to DC conversion stage.  He writes this about how low internal resitance of the battery is better for SQ and doesn't explain why. 

 ...

He conveniently fails to mention the fact that the amp still contains AC to DC circuitry. The battery voltage has to be converted to the correct voltage for the tube filaments (6.3v) and the HT for the tubes (150v or more). This is done with a SMPS (switched mode power supply), same principle as the power supply in a PC, which converts DC to AC, steps it up in a transformer, then converts it back to DC. Worse, it does this at high frequencies (above 20 KHz) which requires careful design to prevent high frequency switching noise affecting the audio - typically causing low level buzzing or whistling sounds. 

post #681 of 1671
Quote:
Originally Posted by SilverEars View Post
 

I was at RWA's website checking out the Isabella Amp.  http://redwineaudio.com/components/isabella-re

 

And something perplexing I've run into.  This amp is run on a battery to elimate AC to DC conversion stage.  He writes this about how low internal resitance of the battery is better for SQ and doesn't explain why.

 

Low internal resistance of a battery is a good thing because it allows the battery to act more like an ideal DC source, with no voltage variations that are dependent on the load being driven. However, as long as the device has proper voltage regulation after the batteries, and the battery capability is selected intelligently based on the expected and required load (depending on what exactly it is powering), there really shouldn't be any difference at all. For a preamp, this is especially amusing, since a preamp won't have a significantly variable load or current requirement (since it's going to be hooked up to a high-impedance input to an amplifier). The demands on something like a cell phone battery or a portable headphone amp battery will be much greater due to the fact that a headphone output will have to supply significant amounts of current, unlike a preamp output.

 

Also, there's no reason at all why driving something off AC can't be just as clean and noise free as driving something off a battery, though there are a few additional considerations (especially if you have a grounded AC plug, which introduces the possibility of ground loops). It is actually true that running a component off battery can remove a lot of these concerns, but any well-designed audio component shouldn't suffer from noise introduced by the AC supply anyways.


Edited by cjl - 4/23/14 at 9:50am
post #682 of 1671
Quote:
Originally Posted by Joe Bloggs View Post

I debate the topic with him he brings up a jungle of audiophile jargon, none of which I believe is relevant to the point

That is called "obfuscation" and it is a deliberate argumentative technique used by high end stereo salesmen. Obfuscation is intended to make the customer or person asking the questions become confused, so they will shut up and just buy what they're told to buy.

If you really want to know the truth for yourself, just figure it all out for yourself. You probably won't convince your boss, because he'll just kick up more dust no matter what you say.

Test tone sweeps to determine audible frequency response would be useful to determine differences between IEMs.
post #683 of 1671
Quote:
Originally Posted by Joe Bloggs View Post

How do you blind test IEMs?

Well, there's a slew of CIEM demos coming our way, all with the same shape. Hmm cool.gif

What I'd love to have is some sort of reductive reasoning with scientific backing proving that frequency response, phase response and distortion are all we need to look at.


Okay, blind testing IEMs would be a problem. 

 

How about running two IEMs in parallel?  One goes in one ear, and one goes in the other.  If you can make them sound the same as whichever of the IEMs is the target, maybe that would begin to get through.  One ear has the preferred IEM, and one ear with a lesser phone is made to sound identical enough the stereo presentation suffers not at all.  If he is determined to never admit otherwise the truth is nothing will convince him.  If he is open to being convinced maybe this would start to get the seed planted as something he actually experiences. 

post #684 of 1671
Quote:
Originally Posted by cjl View Post
 

 

Low internal resistance of a battery is a good thing because it allows the battery to act more like an ideal DC source, with no voltage variations that are dependent on the load being driven. However, as long as the device has proper voltage regulation after the batteries, and the battery capability is selected intelligently based on the expected and required load (depending on what exactly it is powering), there really shouldn't be any difference at all. For a preamp, this is especially amusing, since a preamp won't have a significantly variable load or current requirement (since it's going to be hooked up to a high-impedance input to an amplifier). The demands on something like a cell phone battery or a portable headphone amp battery will be much greater due to the fact that a headphone output will have to supply significant amounts of current, unlike a preamp output.

 

Also, there's no reason at all why driving something off AC can't be just as clean and noise free as driving something off a battery, though there are a few additional considerations (especially if you have a grounded AC plug, which introduces the possibility of ground loops). It is actually true that running a component off battery can remove a lot of these concerns, but any well-designed audio component shouldn't suffer from noise introduced by the AC supply anyways.

I see what you mean, if the regulator comes after the battery, and if it has a very low input impedance, the drop of voltage in the internal resistance will be more significant.  The impedance of the battery should be very small, but of course the drop across the load will depend on ratio so the load should have significantly higher impedance.

post #685 of 1671
Quote:
Originally Posted by esldude View Post


Okay, blind testing IEMs would be a problem. 

How about running two IEMs in parallel?  One goes in one ear, and one goes in the other.  If you can make them sound the same as whichever of the IEMs is the target, maybe that would begin to get through.  One ear has the preferred IEM, and one ear with a lesser phone is made to sound identical enough the stereo presentation suffers not at all.  If he is determined to never admit otherwise the truth is nothing will convince him.  If he is open to being convinced maybe this would start to get the seed planted as something he actually experiences. 

That's actually a pretty tall order... Even if I had two identical DAC/amps (thus eliminating variation in interface latency), the time shift introduced by even a minimum phase EQ on the lesser phone would make hash of the stereo image, and I'm not savvy enough to measure and correct for this time shift.
post #686 of 1671
Quote:
Originally Posted by Joe Bloggs View Post


That's actually a pretty tall order... Even if I had two identical DAC/amps (thus eliminating variation in interface latency), the time shift introduced by even a minimum phase EQ on the lesser phone would make hash of the stereo image, and I'm not savvy enough to measure and correct for this time shift.

Set a delay in the music player software.

 

Depends on how the software handles it, maybe a flat EQ has the same signal delay?

post #687 of 1671
post #688 of 1671
Quote:
Originally Posted by Joe Bloggs View Post


That's actually a pretty tall order... Even if I had two identical DAC/amps (thus eliminating variation in interface latency), the time shift introduced by even a minimum phase EQ on the lesser phone would make hash of the stereo image, and I'm not savvy enough to measure and correct for this time shift.

 

The time shift wouldn't be audible anyway.

post #689 of 1671

 

Dynamic compression and hot mastering are two completely different things. One moves all of the sound into a narrower range, the other chops the whole top off in clipping.

post #690 of 1671
http://stereos.about.com/b/2014/02/26/why-audiophiles-might-be-wrong-about-the-loudness-war.htm
Quote:
Originally Posted by Brent Butterworth 
The results will surprise and probably infuriate audiophiles who've decided dynamic range compression is the greatest evil since -- well, whatever they were upset about last year.
The snark is strong with this one...
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