[Mitchell4500]

So I have a pair of Shure SE315 that I love...  Trouble is they lack Bass unless boosted properly - what I mean is they are super flat when plugged into a generic source like my laptop where when plugged into my sansa with proper EQ the bass comes alive and is rather impressive while maintaining the highs and mids that the 315s are known for. 
 
Recently at a head-fi meetup in the Philadelphia area (oct 26) I had the opportunity to try my headphones with some portable amps and not so portable Tube amps. I noticed a difference in the "aliveness" of all the frequencies/bands/ect .... (basically it sounded nice. I wanna do now)
 
---
 
So I was looking at various diy headphone amps and Ive been wanting to learn all the electrical stuff for awhile now... I wanted to make a 3 opamp design ... a left, right, and bass channel. Each channel having its own op amp... The bass channel would be sourced from the pre-opamp left and right -> mixed together -> apply low pas filter -> amp -> mix back out into the post-opamp...  Put it all in a neat little container... Maybe some modular boards using 8pin headers and pcbs for each channel / mix.   
 
I thought of this idea while using my sound board - Id create channels for specific frequencies and route them to appreciate speakers/amps.
 
Is this a waste of time? Am I over doing it? Am I plain wrong? I was thinking of using these op amps. http://www.ebay.com/itm/261269062286?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

[Avro_Arrow]

What you are think of isn't really practical.
Just add some bass boost in your feedback loop.

 

[jcx]

you can build passive EQ, for the high sensitivity of the 315 you really want attenuation anyway - amplification is not needed with typical DAP, laptop headphone out - you have plenty of amplitude for >12 dB bass boost
 
http://www.linkwitzlab.com/reference_earphones.htm
 
 
Quote:

The SE315 was announced in August 2010, with a U.S. retail price of $250. It is available in clear or black.
 
The detachable 64 inch (163 cm) cable has a wire-form fit that can be molded to a specific outer ear shape. The single driver is a balanced armature type with a tuned bass port. The attenuation of outside noise is rated up to 37 dB depending upon the seal between the earphone sleeve and the ear canal.
 
The SE315 sensitivity is 116 dBSPL/mW; 5 dB greater than the SE310.
 
The SE315 impedance is 27 ohms; 1 ohm less than the SE310.
 
The SE315 frequency response is 22 Hz to 18,500 Hz.

 

[Mitchell4500]

So a passive amp would be one inline with the source? un- Powered?    source (headphone out amped) ->  passive eq -> headphones? 

 

[jcx]

yes