[cosmopragma]

I've searched around this morning and didn't find the article about the Fraunhofer absorbers I was looking for, but I've found an animation of the effect of room modes.
OMG, that reminds me why I like headphones so much.

 

[Wodgy]

I don't think this has been mentioned before... here's an excellent presentation by Floyd Toole (one of the original NRC researchers in loudspeaker design) discussing room effects:
http://harman.com/wp/pdf/Loudspeakers&RoomsPt3.pdf
What makes this different than a lot of other discussions of room effects is that he actually works through the analysis and treatment of a couple of realistic example rooms, from start to finish. Really interesting stuff. I found it especially interesting that even without any budget constraints Dr. Toole can't manage to get even bass for both rows of seats in the example home theatre. Physics can be kind of humbling sometimes.

 

[ooheadsoo]

Bass is truly gnarly stuff in relation to rooms. Those really highly paid room treatment experts say if they can get a room to within +/-6db, they've done their job.

Headphones? Ever look at any of the headroom graphs? Hardly flat frequency response...

 

[cosmopragma]

Quote:

Originally Posted by ooheadsoo Bass is truly gnarly stuff in relation to rooms. Those really highly paid room treatment experts say if they can get a room to within +/-6db, they've done their job. Headphones? Ever look at any of the headroom graphs? Hardly flat frequency response...

In order to simulate the naturally occuring distortion due to the effects of sound coming from different angles in speaker audio vs. headphone audio and music produced for speaker audio (room distortion) headphones aren't supposed to response flat.
In theory there are free field equalization and diffuse field equalization.
In practice there is usually something in between, different companies are using different "house equalization" or are even offering differently equalized flavours of a model.

 

[Calanctus]

I thought I'd post about a room treatment I tried which makes a significant difference.

I'm just getting into dealing with room acoustics, and before investing the bigger $$$ in bass traps and diffusors, I bought a set of 'corner busters'. These are triangular pieces of rigid material which fit into the 4 upper corners of the listening room.

And...they work. Soundstage is more clear and stable, and a few recordings sound significantly different--there seems to be a resonance in my room at a certain frequency which is cancelled by the corner busters. This effect was quite unexpected. It's most noticeable on some tabla recordings, but it's not a bass frequency--more of a lower midrange, the hum that you get from the larger tabla drum.

 

[ooheadsoo]

Quote:

Originally Posted by cosmopragma In order to simulate the naturally occuring distortion due to the effects of sound coming from different angles in speaker audio vs. headphone audio and music produced for speaker audio (room distortion) headphones aren't supposed to response flat. In theory there are free field equalization and diffuse field equalization. In practice there is usually something in between, different companies are using different "house equalization" or are even offering differently equalized flavours of a model.

Good speakers are usually designed to measure flat before room interaction, not after. Who can say what effect the room and your ears will do to the sound? Speaker sound needs to pass through your ears too, no matter how well your room is treated

There's no doubt that headphones aren't even close to being flat in FR even after they hit your ears. Take sennheiser vs. grado. Night and day FR. The plots show it too