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Rethinking Listening Fatigue

Listening fatigue to me has always been a sure sign that something was wrong with an audio system.

It is a useful test of a system, because it is not always immediately apparent - a fact which has undoubtedly helped Dr Bose get rich.

I have always thought fatigue was mainly a product of digital, overly bright tweeters, and/or a sonic signature that puts too much emphasis on "resolution" and not enough emphasis on high quality midrange.

But lately I am wondering if I have been oversimplifying things.

As you can see in my system link, I am using a pair of ATC SCM 7's with a pair of Behringer amps used as monoblocks for my desktop and PC audio.

Recently, I have added a Hagerman Technology USB interface box, which goes into an Audio Research DAC 5.

To my ears, the ATCs have a slightly laid back, non fatiguing sound typical of many English products which suits my tastes just fine, particularly for very nearfield listening.

What is curious, however, is that I am starting to realize that this system sounds really different depending on the volume and/or the time of day.

At times, this little system sounds wonderful. I feel I can listen to it for hours, with the speakers < 3 feet away from my ears and in many ways, I enjoy it more than the big system.

Detail for both music and movies is very clear and I have especially noted that I am better able to discern dialogue with these speakers, without ever feeling like the sound is too "etched' or embossed.

At other times, however, I feel quickly fatigued and suddently overwhelmed with an unpleasant this is way too loud, the music is congested and I must be bothering my wife sensation.

No one I know has ever described ATC monitors as fatiguing, so I am starting to wonder:

1) Despite relatively high power of the Behringer amps in a monoblock configuration, is it possible that they are overdriven and distorting at not terribly loud levels?If so, would this type of distortion, rather than overly hot tweeters, be a more obvious culprit for fatigue?

2) Or could grunge in my AC also contribute to listeners fatigue? Would some of you recommend a line conditioner rather than an upgrade to the amps for this desktop system?

The fatigue I am trying to describe always manifests itself as 'this is uncomfortably loud' sensation.

Thank you for your thoughts and comments on this and the topic of listeners' fatigue.

cwlondon
cwlondon
blindjim
3,092 posts
 
to point the finger at one aspect of your system now probably isn't the most appropriate way, though for now, I'll go along with SMS' note. A decent passive filter shouldn't run much and it can translate into another rig or be sold again if it's not the solution. Even a simple system has several parts to it. Anyone of which can induce a problem.

iTuens too might be a part of the issue. Though I'd not put much money on it. I did notice a bit of a difference after installing an ASIO driver I bought online... and a far greater (mo better) difference when I switched to J River's player. Way better!

My take is from what you said initially... certain hours of the day things get wanky... regardless the music being played. Well that sounds like power gremlins are kicking up their heels now and then.

At the offidce all sorts of things can be routinely energized for a time and induce junk onto the grid. PC back up power supplies are known to be really bad for this Cell phone chargers, fax machines, etc. especially if close by aren't audio friendly items.

Some sort of good filter ought to do it for you. Like a PSA Duet or even a PSA UPC 200 should do the trick, given a decent power cord is used as the supply. you might even get away without having to buy a better one than they come with too.
atmasphere's avatar
atmasphere
12,107 posts
 
Kijanki makes a good point and worth expanding. Audio systems make distortion, and the distortions that we as humans find the most objectionable are the odd orders. In fact the human ear uses the presence of the 5th, 7th and 9th harmonics as a means of detirmining loudness.

If the structure of these harmonics is altered even by 100ths of a percent we can hear it. 'Harsh', 'brittle', 'clinical', 'bright', 'chalky', etc. are all audiophile terms that describe surprisingly small amounts of extra odd-ordered harmonic content.
rodman99999
6,206 posts
 
My first thought would be toward Intermodulation Distortion, which is a particularly annoying form unlike Harmonic Distortion. The correct definition of which is distortion created when an amplifier creates a frequency, the sum or difference of two other frequencies that it's amplifying. Of course most amps that have that propensity don't stop there. They tend to keep intermodulating the distortion with clean signal, and it's all an odd-order mess. Of course- The amp is also supplying gain to these distortion products, wasting it's power in the process and can sound "compressed" as a result. More info:(http://www.aeroflex.com/products/signalsources/signalgens/appnotes/846.pdf) (http://www.analog.com/en/content/0,2886,760%255F788%255F91329,00.html)
shadorne's avatar
shadorne
7,477 posts
 
To try and tie things to together.

We are all talking about the same thing as being fatiguing.

Higher order harmonics from intermodulation be it TIM or other forms of distortion.

This happens with a bad amp design. It also happens when an amp is overdriven. It is worse when an SS amp is overdriven.

However as Reubent pointed out it can also be on your source media (CD or iTunes). Audio compression is often overdone in the mastering process - it make all loudness levels on a CD match and give the CD an "etched" and aggressive sound. It does the same thing as clipping on an amplifier - it creates a whole bunch of higher order odd harmonics...so it sounds the same.

Try grabbing any pop/rock CD that you bought in the 80's and compare it to something you bought in the last few years. It is pretty obvious. In the last five years is it has begun to affect other genres such as jazz and classical.

Here is an explanation

And hear is a quote for you

"I listened to all the CDs submitted to NARAS for consideration in the 'Best Engineered Non-Classical' Grammy category. We listened to about 3 to 4 cuts [from the TWO HUNDRED AND SIXTY SEVEN albums submitted]. Every single CD was squashed to death with no dynamic range...the Finalizers and plug-ins were cranked to 'eleven' so that their CD would be the loudest... Not one...attempted to take advantage of the dynamic range or cleanliness of digital recording.

-Roger Nichols - Grammy winning engineer for Steely Dan, Beach Boys and more - Jan. 2002 Eq Magazine
shadorne's avatar
shadorne
7,477 posts
 
Oh and for those who like detail. Here is some sobering reading that explains how your DAC is very likely clipping due to illegally loud redbook on most recent CD's.

And CD sales are declining...and the industry wonders why?

Well they get what they deserve - if, as quoted above, 267 of the best CD's nominated for non-classical grammys are all "squashed to death" no wonder everyone agrees that digital is fatiguing! Why pay good money for a bad product -you can download it for less.

CD and iTunes quality is truely terrible these days. No wonder Vinyl is still around - you physically can't make Vinyl hard clip in the way a CD can. Vinyl phsyically cannot sound as harsh and bad as "illegal" redbook CD.
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