[IA64]

I've always wondered if I am supposed to use an equalizer with a top tier IEM or Headphone. 
 
No matter how good my source and headphones are, I always find the need to EQ this thing. WIth Shure SE535 I had to boost the 30-50 Hz 3dB. With JH16 I had to boost the 4 and 8KHz 2dB . With other headphones I demoed it's the same story.
 
With JH16 things are even more complex...boosting high mids and treble works well with Jazz and Blues whatsoever but ruins other genres like bass tracks or techno.
 
 
Isn't a good phone supposed to work without the need of equalization ? And what are the downsides of using one ?  I don't like the idea of tuning the sound and messing with the sound signature but I feel the need to do it everytime.

 

[El_Doug]

A "good phone" can still respond very well to EQ.  Something with low distortion, great speed, and amazing comfort may still not have the frequency response you'd like... nothing wrong with tweaking it to suit your tastes

 

[IA64]

Quote:

A "good phone" can still respond very well to EQ.  Something with low distortion, great speed, and amazing comfort may still not have the frequency response you'd like... nothing wrong with tweaking it to suit your tastes

 
Isn't the source distortion the major issue ? 
 
Another question, does what you say imply that any 3 way 6 driver IEM will sound the same if properly tuned with an equalizer  ? 

 

[jaddie]

Remember that all of this audio stuff is really an illusion requiring a certain willingness to accept it.  Sometimes a bit of EQ can help make the illusion more acceptable. Even if you could precisely reproduce the original sound field you may desire, say, a bit more bass.  Sometimes reality isn't perfect either.

 

[stv014]

Quote:

Isn't the source distortion the major issue ?

 
It is not likely to be much of an issue if you avoid clipping by using the EQ correctly.

 

[anetode]

If the expensive headphone possesses notably lower levels of distortion then it will respond better to EQ than a cheaper headphone with less favorable distortion characteristics.
 
If this is something you are seriously considering, look up http://diyaudioheaven.wordpress.com/schematics/headphone/ - Solderdude has put a respectable amount of work into setting up custom EQ boards for a range of headphones. Alternately there are quite a few threads in head-fi about software-based solutions where users have shared their preferred correction settings.

 

[xnor]

I don't think equalization is blasphemy at all, even with the most expensive headphones. Imo, almost any headphone needs equalization, some more, others less. The better ones need less and produce cleaner (less distorted) sound.
 
Yeah, if you use software to EQ make sure to pull the pre-gain down to a level where there's no clipping and turn the volume on your amp up a bit to compensate.

 

[PleasantSounds]

Quote:

 
Isn't the source distortion the major issue ? 
 
Another question, does what you say imply that any 3 way 6 driver IEM will sound the same if properly tuned with an equalizer  ? 

 
You should be able to get pretty close with the tonal characteristics, but there are other important properties that equalizer will not correct, for example distortions.
 
Regarding the source distortions - equalizers may cause some phase shifting of the modified frequency bands, which would be heard as a change of the sound source location or more likely reduced precision of that location. The key however is to avoid clipping as others already said.

 

[streetdragon]

Eq fine tuning for optimization is good since it allows you to maximize your enjoyment to your equipment. (and you can change the tuning depending on your mood too)
Clipping however... is blasphemy.

 

[xnor]

The location of a sound source would only change if you equalize left/right independently, which is only needed if the headphone has channel imbalance (and therefore inaccurate localization) to begin with. So you'd actually improve localization.
 
The precision of localization is problematic with headphones anyway, due to the strong stereo separation and almost completely disabled HRTFs. Also, phase shift is usually only audible with special signals (not music) and crazy amounts of phase shift. Else nobody would listen to loudspeakers or multi-driver headphones, both of which produce huge amounts of phase shifts. Even single driver speakers/headphones produce larger phase shift than smooth equalization and you can actually correct those shifts (partly) with an EQ.

 

[mikeaj]

In my opinion, you never really get the "intended" sound of any headphone or IEM, as it depends on fit, ear shape, etc.
 
Even if there were a recognized and known optimal response and some expensive model were to nail it perfectly for your ears, it's not really a big deal to change things if you want.  Who cares what others think.  Do what sounds right to you.
 
And even that's assuming your goal is to best reproduce the source material.  That needn't necessarily be the objective, considering how many records are "produced" these days.

 

[jaddie]

Quote:

Regarding the source distortions - equalizers may cause some phase shifting of the modified frequency bands, which would be heard as a change of the sound source location or more likely reduced precision of that location. The key however is to avoid clipping as others already said.

The mechanisms, acoustic and electrical that cause response anomalies in headphones also cause phase shift as well.  If an equalizer were to compensate for a response (and therefore phase) anomaly in a headphone, it would compensate at pretty well for the phase response too.  
 
Research into the audibility of group delay was done in the 1980s in response to the rather wicked multi-pole analog anti-aliasing filters of the time.  The key papers aren't at my fingertips, but the results mainly were that it isn't the total amount of group delay but the rate of change with frequency that becomes audible, and only when there is a rather surprising amount of it, much more than found in a typical 1/3 octave band equalizer.  Where phase shift around equalizer bands becomes an issue is when one stereo channel doesn't precisely match the other, otherwise it's a non-issue.