Just a noob question for the geniuses here

[frobroj]

Hey all - Just a dumb noob question. Picked up a umik-1 mainly just to get some real rudimentary measurements on some Open Alpha headphones I printed so I had a good idea where to start with tuning. I measured another set of headphones I have that I put together some time ago. They have some home made planar drivers in them. After measuring the fostex and some hifiman drivers I ran the home made planars through and got a very different result when it comes to phase. The other two had smooth flowing phase throughout but the home made planars were spiking to 180degrees and were all over the place. I was wondering if you all could tell me what this might indicate.

https://imgur.com/a/CzgRhWF

Appreciate any advice you can give. Note the drivers sound great so whatever the phase issue is it does not appear to be effecting the quality in any way. Would reversing polarity possibly cause readings like this?

Really appreciate your time! Thanks all!

 

[UKSPAWN]

hmm, dont think you can measure headphones with UMIK1 *properly*. headphones require a seal against the head/ears. as far as i know anyway.

 

[frobroj]

Yeah I put together a makeshift seal of several inch foam with a thinner foam stuck to it overlaid with felt. Works well enough. Like I said not looking to do super detailed measurements but just get some idea what frequencies need tuning.

 

[UKSPAWN]

hm, ok. i guess that will work comparing changes that you make. but not comparing to any other measurments not taken on that same rig, and also taking it on and off again could be problematic if its not exactly the same each time.

But i dont know if i'd trust the measurments. over ear headphones also take into account the external ears shape etc (among other things), so they are never flat and if you tried to make a headphone measure flat like as with an in-room response i believe it would sound 'bad' / harsh / sharp / no bass etc etc

So as for what to tune i wouldnt know where to start without reearching...
id start by researching why headphones and manufacturers try to follow a certain frequency response curve and that will be related to Psychoaccoustics.

Once you know why for example they put a 'dip here' and 'boost X', then you can start to follow those "rules"

But id just wear them and tune them to how you like them with songs you know.

Make a change or 2, then listen to a few songs and then repeat with say 4-5 songs on repeat. spend a few hours doing that IMO

 

[jtalden]

The measurement indicates the polarity is inverted. You can remeasure with the headphone polarity corrected, or you can just go to impulse tab controls to invert the impulse of the current measurement within REW.

As UKSPAWN noted, using a umik-1 for headphone measurement is problematic.

 

[frobroj]

Yeah sorry guess I didn't post my question well. Not really looking for help on tuning but saw a very strange Phase reading on a different pair of headphones and was curious what it meant ie what might cause that particular kind of reading. The link shows the results. I measured several pairs of headphones and all came back with very smooth phase graphs but this particular pair came back with very strange one spiking to 180 degrees. Just curious what may be the cause of that and if it is anything to be concerned with.

 

[frobroj]

Thats what I wondered. Thanks jtalden! I will take a peek. Appreciate the help and pointing me in the right direction. Yeah eventually I will get better gear but for now cant afford it. Thanks again for the help!!!