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Sony MH1 R&D Story ...and discussion. - Page 16

post #226 of 232
Quote:
Originally Posted by luisdent View Post
 
Look on the bright side.  Now you can mod one! :-P  

I have lots of nice colourful tips too. :-) I even got this one for €10 new, which is the cheapest I've seen.

post #227 of 232
Quote:
Originally Posted by luisdent View Post
 

 

Could you draw roughly what sort of eq curve this mod would mimick?  How much bass cut at what frequencies, etc.?  Really curious.

 

On another note... I'm so on the mh1 bandwagon! haha.  I got a pair for $20 just to check them out.  Completely blown away!  These things are up there with the er4s to me.  They are more bassy, but that isn't always a bad thing.  First, I simply eq the bass down with ONE single eq point.  Second, sometimes it is kind of relaxing and the bass doesn't interfere with the rest of the spectrum as much as on most other iems.


...


I'll have to check these forums more often.

 

The frequency response of my "mod" should be similar to that of a dedicated front vent. There are graphs of its effect on Rin Choi's blog. Basically, he drilled a front hole and controlled the leakage with various Knowles dampers. I didn't have a bunch of disposable MH1 samples, so I went with the micro-punctured sleeve instead (this was well before Rin's analysis). It's not perfect because the deep bass response is the first to go. If you make the vent large enough for the mid-bass to be flat (around -10 dB at 100 Hz), you'll hear a very audible roll-off in the bottom octave. It'll graph even worse if you go by Sean Olive's compensation or believe in the missing 6 dB effect. I found a good compromise by keeping the vent small. But I'm the kind of person who insists on getting the mid-range and mid-bass right, even if it means that the response is down a few dB at 30 Hz. To me that's less musical damage than the other way around. Sins of omission vs. commission.

 

It seems that Rin found a pretty good solution to the excessive bass problem: he decreased the volume of the rear air chamber. Air is a compressible fluid, and if there's less of it behind the driver, the harder it is to move the diaphragm. Since you need more excursion for those really low bass notes, reducing the volume (and thus the acoustic compliance) means that you'll get less bass as well. I'll have to try that trick on some other cheapo IEMs, e.g., Philips 3580.

 

The way I'm hearing it, the presentation in the upper midrange is different from the ER4S. It's actually closer to the ER4P here. I'm hearing the ER4S pretty much the same as Linkwitz; there's a peak near 2.5 kHz compared to my various sets of speakers. Linkwitz also notes the half-wavelength resonance at 7-10 kHz, which can be addressed by very deep insertion or an absorbent tip like a TX-100. I don't hear that on the MH1 at any insertion depth, even though you can see something that looks like it on Sead's graph in post #211. BTW, the Apple IEM has a sound that's in the same ballpark as a bass-reduced MH1 if you add series resistance with a passive inline volume control and Comply Whoomp tips. I don't listen loud enough for the distortion to be a problem.

post #228 of 232
Quote:
Originally Posted by yuriv View Post
 
Quote:
Originally Posted by luisdent View Post
 

 

Could you draw roughly what sort of eq curve this mod would mimick?  How much bass cut at what frequencies, etc.?  Really curious.

 

On another note... I'm so on the mh1 bandwagon! haha.  I got a pair for $20 just to check them out.  Completely blown away!  These things are up there with the er4s to me.  They are more bassy, but that isn't always a bad thing.  First, I simply eq the bass down with ONE single eq point.  Second, sometimes it is kind of relaxing and the bass doesn't interfere with the rest of the spectrum as much as on most other iems.


...


I'll have to check these forums more often.

 

The frequency response of my "mod" should be similar to that of a dedicated front vent. There are graphs of its effect on Rin Choi's blog. Basically, he drilled a front hole and controlled the leakage with various Knowles dampers. I didn't have a bunch of disposable MH1 samples, so I went with the micro-punctured sleeve instead (this was well before Rin's analysis). It's not perfect because the deep bass response is the first to go. If you make the vent large enough for the mid-bass to be flat (around -10 dB at 100 Hz), you'll hear a very audible roll-off in the bottom octave. It'll graph even worse if you go by Sean Olive's compensation or believe in the missing 6 dB effect. I found a good compromise by keeping the vent small. But I'm the kind of person who insists on getting the mid-range and mid-bass right, even if it means that the response is down a few dB at 30 Hz. To me that's less musical damage than the other way around. Sins of omission vs. commission.

 

It seems that Rin found a pretty good solution to the excessive bass problem: he decreased the volume of the rear air chamber. Air is a compressible fluid, and if there's less of it behind the driver, the harder it is to move the diaphragm. Since you need more excursion for those really low bass notes, reducing the volume (and thus the acoustic compliance) means that you'll get less bass as well. I'll have to try that trick on some other cheapo IEMs, e.g., Philips 3580.

 

The way I'm hearing it, the presentation in the upper midrange is different from the ER4S. It's actually closer to the ER4P here. I'm hearing the ER4S pretty much the same as Linkwitz; there's a peak near 2.5 kHz compared to my various sets of speakers. Linkwitz also notes the half-wavelength resonance at 7-10 kHz, which can be addressed by very deep insertion or an absorbent tip like a TX-100. I don't hear that on the MH1 at any insertion depth, even though you can see something that looks like it on Sead's graph in post #211. BTW, the Apple IEM has a sound that's in the same ballpark as a bass-reduced MH1 if you add series resistance with a passive inline volume control and Comply Whoomp tips. I don't listen loud enough for the distortion to be a problem.

 

I tried the earpods and while I was impressed for a while, once I started hearing the distortion of my pfe112 and knew what to look for, I can't really listen to the earpods anymore.  The irony is that I located where the distortion was before even looking at graphs.  I always felt the treble of the earpods was distortion free and better than the pfe (distortion wise), but that the sounds was funky somehow.  I came to the conclusion that the bass just didn't sound good for some reason.  I checked a graph and the bass is where all of the distortion is with the earpods.  Interesting.

 

Anyhow, the mh1 sounds a lot flatter to me than the earpods without modification, although they aren't bad.  The mh1 is just smoother and more level end to end.  But they do have excess bass.  However, you need a lot more eq to really flatten the earpods without resistance, etc.

 

I insert the mh1 mid ear now, so it reduces treble peaks well and I just eq the bass down.  This is a very flat result for me.  I'm hesitant to do any mods, because I don't see any that modify only the area of the bass that is problematic...

post #229 of 232
Quote:
Originally Posted by luisdent View Post
 

 

I tried the earpods and while I was impressed for a while, once I started hearing the distortion of my pfe112 and knew what to look for, I can't really listen to the earpods anymore.  The irony is that I located where the distortion was before even looking at graphs.  I always felt the treble of the earpods was distortion free and better than the pfe (distortion wise), but that the sounds was funky somehow.  I came to the conclusion that the bass just didn't sound good for some reason.  I checked a graph and the bass is where all of the distortion is with the earpods.  Interesting.

 

Anyhow, the mh1 sounds a lot flatter to me than the earpods without modification, although they aren't bad.  The mh1 is just smoother and more level end to end.  But they do have excess bass.  However, you need a lot more eq to really flatten the earpods without resistance, etc.

 

I insert the mh1 mid ear now, so it reduces treble peaks well and I just eq the bass down.  This is a very flat result for me.  I'm hesitant to do any mods, because I don't see any that modify only the area of the bass that is problematic...

 

I wasn't comparing the MH1 to the Earpods, which really are closer to earbuds than IEMs. I was referring to the newest revision of the Apple In-Ear Headphones, model ME186LL/A. I use a Monoprice inline volume control to add an equivalent series resistance while retaining the use of the pause, play, track advance, and volume up/down buttons.

 

As for the Earpods, you can get a ton of bass out of them, even down to the bottom octave, when you shove them in your ears and get a partial seal. Unfortunately, if you pull them out far enough to get them flat at 100 Hz, the bass response rolls off very quickly. The effect is similar to a front vent on the MH1. The genius of the design is that the listener can adjust the fit to taste. For me a good compromise is to tolerate a small mid-bass hump in order to preserves some output below 40 Hz. The HD600 has something like this. The ME186LL/A + series resistance doesn't make this compromise. BTW, you can get a good idea of the front vent's effect on the MH1 by wearing  sleeves that are one size smaller than the one you use to get a good seal. Or you can try very shallow insertion so that you get a just little leakage. Fiddle with it until the bass sounds best.

 

Unlike the MH1, the Earpods have a peak somewhere between 1 kHz and 2 kHz, and a resonance (a spike in the response) around 6 kHz. Many listeners (including me) like the sound a lot better when you put earbud foam covers around them. I suspect that the foam acts as an acoustic damper that blunts the spikes in the frequency response. I'll have to run a tone sweep to verify this, or wait for measurements. Like the MH1, the Earpods' frequency response also doesn't change when you add series resistance; the impedance vs. frequency plot is practically flat. You can mess with the Earpods' tuning is with the fit, partial blocking of the various acoustic vents, and acoustic dampers.

 

Of course, if you have a good parametric EQ, just use that. It's just too bad that non-jailbroken iOS and Android don't have system-wide EQ. These various work-arounds are really only for apps that don't have EQ.


Edited by yuriv - 11/14/13 at 12:23am
post #230 of 232

Anyone any links to people with a photo/video blog of re-cabling these?

post #231 of 232

Is mod 2 reversible?

post #232 of 232
If u take out the whole foam cylinder.. don't cut it in half n keep it safe.. Then yeah..! You could put it back anytime u want.
Edited by Aakash - 11/26/13 at 4:59am
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