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Headphone EQ - Done.

post #1 of 13
Thread Starter 

For everyone who ever wanted to EQ his headphones, but got daunted by all the discussion here of the hows, whys, how-nots, why-nots, and what-nots posted in other threads:  How would you like high precision headphone EQ for your specific model, based on lab-grade measurements... for $.99?

 

Here's a review of the new Audyssey "amp Media Player" app for IOS devices.  

 

Headphone EQ done right - for the rest of us.

 

Have fun, go nuts, and enjoy the great headphone EQ. 

post #2 of 13

I got this one for my iPad mini. I felt it did a decent job for the price:

https://itunes.apple.com/us/app/accudio-pro/id553759905?mt=8


Edited by ultrabike - 12/21/12 at 8:17pm
post #3 of 13
Thread Starter 
Nice app, though it looks like the simulation function is the exact opposite of classic headphone EQ. Nice it handles FLAC, something I suggested to Audyssey for a future update too. It's also 5X the price of amp.
post #4 of 13

It allows you to shoot for flat given a headphone. It also simulates other headphones (not just flat). Additionally, it includes my HD558 and KSC-75s, which the Audyssey didn't seem to have.

 

I still bought the Audyssey app biggrin.gif... Did improve my HD202s smily_headphones1.gif

post #5 of 13
Thread Starter 

How would you compare the results from both apps?  Are they similar?

 

From the Accudio website, such as it is, they imply a flat target curve, which is probably not what they really do.  Their measurement technique is different than what Audyssey does.  

post #6 of 13

I think Accudio goes for calibrated flat (check http://en.goldenears.net/451 under question "So you have random, arbitrary standards?".) I believe this is similar to what Audyssey claims: Striving for a "target curve" that is not flat in the absolute sense (according to your blog biggrin.gif)

 

I don't know what Audyssey's target curve is. Accudio seems to use Diffuse Sound Field as target curve. Whether this is correct or not is another matter.

 

Unfortunately I cannot compare their performance head to head because Accudio does not support my HD202s, but does my HD558s and KSC-75s, and Audyssey does not support my HD558s and KSC-75s, but does support my HD202s.

 

With Accudio, using flat, I felt my HD558s sounded less mids forward, a little better extended in the bass (less punchy too), and overall more balanced. My KSC-75 became less punchy and bright and the mids came forward. Again, IMHO more balanced. With Audyssey, my HD202 went from severely bloated, dark and a little weird, to more detailed and balanced. In all cases, the improvement was fairly obvious and didn't seem to amplify distortion (at least not too much.) So life is good!

 

Besides FLAC support, one thing that Accudio currently has over Audyssey is that you can emulate other headphones as well. I really like both apps though. They do make a difference for $5 and $1 respectively. I also do not expect miracles, just improvements.

 

From your blog, it seems interesting that Audyssey somehow factors loudness contours to the equalizer, and the tilt control seems pretty slick smile.gif.


Edited by ultrabike - 12/22/12 at 1:01am
post #7 of 13
Thread Starter 

You can hear the effect of Dynamic EQ if you turn Audyssey on and off at different volume settings or at different points in music dynamics.  The thing to know about it is it's not a fixed loudness curve that changes with volume setting only, it's volume setting plus instantaneous signal level. Because it's dynamic, it can stay calibrated to human hearing loudness contour on a moment by moment basis, getting around the Fletcher-Munson-based loudness control's problem of being usually too much compensation, partly because they were based on knob position only.

 

Couldn't get him to talk about the exact target curves, though he did admit to there being different targets for different basic styles.  In the past, Audyssey's research has been done at USC's Immersive Audio Lab, so I'd expect the same in this case. 

 

These guys talk about why there's a need for a non-flat target curve (though they don't call it that). They describe a general target curve for headphones.

http://www.headphone.com/learning-center/about-headphone-measurements.php

post #8 of 13
Quote:
Originally Posted by jaddie View Post

You can hear the effect of Dynamic EQ if you turn Audyssey on and off at different volume settings or at different points in music dynamics.  The thing to know about it is it's not a fixed loudness curve that changes with volume setting only, it's volume setting plus instantaneous signal level. Because it's dynamic, it can stay calibrated to human hearing loudness contour on a moment by moment basis, getting around the Fletcher-Munson-based loudness control's problem of being usually too much compensation, partly because they were based on knob position only.

 

Couldn't get him to talk about the exact target curves, though he did admit to there being different targets for different basic styles.  In the past, Audyssey's research has been done at USC's Immersive Audio Lab, so I'd expect the same in this case. 

 

These guys talk about why there's a need for a non-flat target curve (though they don't call it that). They describe a general target curve for headphones.

http://www.headphone.com/learning-center/about-headphone-measurements.php

 

They are not doing some real-time dynamic range compression deal, right? From the little I know, I would rather not compensate using loudness contours... at least not dynamically. Speakers don't do that AFAIK, and neither will you get that effect in a live performance... I think...

 

It would be nice to turn the loudness curve compensation on and off, while keeping the frequency response target compensation on...

 

Also, I'm not sure what target curves Tyll used to shoot for when at HeadRoom, but these days he is shooting for Independent of Direction: http://www.innerfidelity.com/content/headphone-measurement-proceedures-frequency-response


Edited by ultrabike - 12/22/12 at 12:02pm
post #9 of 13
Thread Starter 

It's not dynamic range compression at all.  I'd HATE that. 

 

My short explanation is, your hearing becomes progressively less sensitive to bass as the sound intensity drops.  If you listen to music at the exact level it was mixed at, no problem, everything is in balance.  If you drop your play level by 20 or 30 dB, what you hear will sound thin.  A fixed "loudness contour" adjustment takes a step closer to repair, but since music varies in level constantly, a fixed curve would only be the right correction at one level, in other words, wrong a lot of the time.  And a traditional loudness control's action is coupled to a volume control position, and knows nothing of the actual sound level at your ears.

 

Dynamic EQ knows the exact sound level at your ear, so its applying the exact compensation for a play level offset.  Since that exact level changes, and the exact correction is frequency dependent, it's not just an EQ curve, but dynamic correction.  It's an exact compensation for what your hearing is doing at low levels, with the goal being to present the original mix balance at all play levels.  If you turn up your play level to something like the original mix level, Dynamic EQ does nothing, it doesn't need to do anything.  Dynamic EQ is level-aware, frequency-aware, and hearing response aware.  Because of all of that, if you weren't aware that it was on, you wouldn't be able to tell except for the rather normal sounding spectrum at low levels.  There's no side-effect, and no compression artifact. You'll hear the difference when you turn it off, though. 

 

Remember, no compensation is actually wrong in this case, it's just that there's be no good way to do loudness comp until DSP came along, so it was always wrong, usually worse than nothing.  Dyamic EQ is not "compensate using loudness contours" because loudness contours cannot ever be applied as a whole fixed curve.  They are intended to show hearing response given a fixed level stimulus.  Music isn't fixed in level or frequency, so the curves never really did apply.

 

Dynamic EQ is also not dynamic compression. which is level-blind above threshold, frequency-blind, hearing response blind, and under subjective control of whoever set it up.  Dynamic compression is almost always audible, and could never be considered any sort of compensation, though very useful in mixing and processing for specific purposes, like broadcast.

 

That's at least how I would describe it. Here's their description:

http://www.audyssey.com/audio-technology/dynamic-eq

 

Some people freak out about changing anything in their audio dynamically.  The problem is, your hearing has already done the damage that way, Dynamic EQ is simply the correct compensation.  Turning it off actually imposes the rather significant error curve of your low level hearing response.


Edited by jaddie - 12/22/12 at 2:43pm
post #10 of 13

I think I get what you are saying.

 

But say you go to a classical music live concert. Passages from the performance might go from very loud to levels you could barely hear. Your perception of frequency response will change at the live performance from passage to passage because of this. These changes in loudness may impose a desired effect in frequency response perception (desired by the author of the score and/or the director of the orchestra.) Alternatively, loudness dependent frequency perception may be already compensated by the director of the orchestra by asking different instrument players to play at different levels relative to one another.

 

If we recorded this performance, and reproduced it using loudness contour compensation, wouldn't we alter the performance original desired effects?


Edited by ultrabike - 12/22/12 at 3:37pm
post #11 of 13
Thread Starter 

Yes, I understand the concern.  I think where it ends up working, though, is that above a certain level you can forget about compensation.  A fair amount of the live performance happens at or above that.  As you move below that point, like in PPP passages, the conductor has to present his best live mix, so if recorded, his "compensation" is built-in, and we don't need to think about it.

 

The amount of correction isn't all that huge until you get to significant play level skews.  You really need it at a level 20 or 30dB below "live", for example, and when that same PPP passage happens at that volume setting, the need for comp is great.  But the difference between no comp and what's applied 20dB below live reference isn't big anyway.  If there were an error, it would be small, especially since it's dynamic, and not there all the time.  Besides, who could argue with a few extra dB of bottom end in, say the opening quiet parts of "The Appian Way" from Pines of Rome?  I wouldn't mind a tad more bass drum there, would you?

 

I would say, give it a listen, give it the acid test.  Try it at all levels and types of music, see what you think.  Try not to think about what's going on behind the screen, just see what you think of the result. 

post #12 of 13

Got Accudio today.  I have owned equ and equalizer since they came out.  Equalizer was always my faveorite.

 

Accudio blows them both out of water.  Its a really incredible app.   Aside from the fact that it is designed exctremely well, and never crashes, and does EVERYTHING i've ever wanted in an app,  its ability to bring headphones to true neutral is ASTOUNDING.

 

i am a bit of a neutrality nut, and have spent months/years chasing neutrality on whatever headphonnes i've owned.   I have had my westone es-5 customs dialed into pretty darn close to neutral for a long time but always though it could probably be done better by someone who actually knew what they were doing or had good equipment...   well actually i thought it may never be done because who the heck has the ability to do this except a very select few, and especially on customs!?!?!??!   Wel i have to say they NAILED IT!  its actually similar to my eq curve (pats self on back biggrin.gif)   but i am not ashamed to say this app has one upped me and my es-5's have never sounded better.

post #13 of 13

Nice!!! I also feel that the Accudio app does a very good job.

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