Just listened to some Fostex T50RPs today... WOW!

[HDMan]

Quote:

I never really had an issue with balance. What you should do is rip out 3.5mm adapter in the left ear cup, fill that area up and top it dynomat and plaxmate. Make sure the amount is as close to each other as possible on both ear cups. Then do a re-cable and your L/R balance should be fixed.
I know this is not a reversible mod, but the T50RP is only $74 and I plan on keeping it. If you plan on keeping yours and the L/R balance issue bothers you that much, you might as well try it.
 

After sealing them properly, I still occasionaly experience a dull left side, so I switched them around so they were facing backwards, left is now on the right side. I was still experiencing a dull left sound, I think my left hearing has been damaged or something, headphones are renouned for causing long term loss of hearing. Bad news for me, as I was just about to outlay on some nice gear. Might see a specialist first, speakers may be the only (noisy) option.
 

 

[thune]

Hopefully it's nothing permanent. My hearing gets wonky in one ear, sometimes. Usually it's just occluded with wax buildup, and also rarely I have "water on the ear". Definitely consult your doctor/specialist.
 
Quote:

After sealing them properly, I still occasionaly experience a dull left side, so I switched them around so they were facing backwards, left is now on the right side. I was still experiencing a dull left sound, I think my left hearing has been damaged or something, headphones are renouned for causing long term loss of hearing. Bad news for me, as I was just about to outlay on some nice gear. Might see a specialist first, speakers may be the only (noisy) option.
 

 

 

[HDMan]

Yeh I cleaned them both out, now the right one seems dull, LOL. Wax is a likely culprit, hope its nothing major, probably just need to rest for a bit.

 

[sphinxvc]

Actually my issue fixed itself, not sure why or how, but I think it may have been some kind of interference issue with some other equipment nearby.  But thanks all you guys who responded. 

 

[symphonic]

Hey guys,
 
I've also been doing measurements as I build my Thunderpants knockoffs. I'm taking a slightly different approach in that I want my cups to be hot swappable, so that I can have different damping schemes for mood/isolation/weight. And just to have fun with different enclosure types. So I'm attaching the baffles to a DT880 type swivel headband and using a strap for cups.
 
I highly recommend that you guys get a hold of Room EQ Wizard (freeware) and a Panasonic WM-61a mic capsule ($3) to perform measurements. You just solder the capsule to the end of some beaten up earbud cord, short the ring and tip on the plug, and you have an adequate microphone for measurements that will also fit in your ear (inside an ear plug). REW does the measurement sweep and deconvolution for you, and you get to see the impulse response etc. I'm able to get good repeatability with these in ear measurements, and each measurement only takes a few seconds. 
 
I want to get a damping scheme that is as close as possible to flat, according to the in ear mic, to use with binaural reproduction, and at least one more for diffuse field EQ. Maybe many more! My dad is a wood turning so I can order up different cup types and sizes.
 
As I get further along I'll post some pics.
 
I actually have a couple of technical questions for you guys as well. First up - what's a good PC oscilloscope? I want to check my square waves. At the moment I'm generating in REW, recording in Audacity, and looking at the waveform...but Audacity keeps crashing. So far I can't get the square wave to look totally flat at 30 Hz like the Thunderpants measurements at Inner Fidelity, but I can get a waveform similar to to measurement of LFFs pair. (Step rise and roughly linear fall to zero.) I'm wondering about the bass vent. In this case, the bass vent does not work like that of speaker system, right (constructive interference)? It's more like a pressure valve? In that case does the shape matter at all? Thunderpants have a single hole. What happens if that is replaced by a line with the same area (e.g. a thin circumference of felt)? And then the mathematical limit of a slightly porous cup?
 

 

[RexAeterna]

Less is more   Why don't you describe more in detail?

what is there explain? hard explaining in detail cause there is not much detail really. i opened cups up, ripped few pieces of mineral wool i took out of old speakers,stuffed it in and then about 5-6 cotton balls over the mineral wool. the bass ports are obviously covered from the mineral wool over top of it. the driver itself has it's original dampening over. nothing changed or modified. i basically just stuffed the crap out of it. i had to man handle the cover and squeeze it shut with force and try to screw it in from there and had to make sure nothing was falling out the sides. i know there is felt over the driver on the outside already but i decided to use pair of foam discs from my 240 and put them over the felt and pads i also had from spare sextetts on them and just stuffed the pads with cotton underneath it to give it more fluffiness.

i got it sounding perfect for me and very natural sounding i personally think(natural sound is very subjective though since everyone hears different). lot people will probably think my pair sounds bass light but if you ever heard the 240DF's,it provides you with very tight bass with great extension. hooked up to speaker outputs i can get good impact if the track has it but it will not accentuate the ''impact'' like how most people like or use to. it just ''presents'' the impact and lets you know it's there,while it will give a good rumble in the sub-bass vibrating your ears. i basically used my 240DF's as a reference tuning my fostex and seems going simple route worked for me. these also have no problem reaching 20khz no sweat if your ears can still hear that high.

 

[sphinxvc]

I tried cotton balls today, did not like it one bit.

 

[RexAeterna]

that's cool. worked out pretty well for me.

 

[HDMan]

Yep me too

 

[drexman]

me three. cotton works well when it's a thin layer. bluemonkey i eagerly wait for your BMF 7. i need sub-bass out of these. also, i know how dynamat/fatmat works in theory, but did you (or anyone else who reads this) expirience real and noticable sound quality effect? i want to be sure before i buy it.

 

[CafeRocker]

This is a follow up from a post from a couple of days ago about the differences between Shure 840 and 940 pads.
 
I find that the 840 pads give tighter more accentuated bass.
 
The 940 pads bloat the bass a little and add some sparkle to the highs.
 
I tried them by themselves, and piggybacked with the stock pads. In both cases, I found the sound to be much much better when piggybacked with the stock pads; sound stage and instrument separation were much improved. (FYI: the inner felt had been removed from both pads)
 
 
I also tried the 840 pads with the 940 pads on top. I found this to be my favorite. The sound is similar to the 940 pads piggybacked on the stock pads, but with more bass quantity (although still slightly bloated). The slight sparkle the 940 pads bring makes listening much engaging to me - it's just a funner sound. 
 
Oh, and the 940 pads win in the comfort category, hands down.
 
What I need advice on, is how to permanently attach the two pads together. Is there an adhesive that would be good for this? How has everyone else been doing it?

 

[Arleus]

This is an interesting approach, symphonic. I was thinking of doing something similar before, but with the Roland Binaural mics (I forget the model name now). Unfortunately, I ran into the problem that they require plug-in power, which my audio interface can't provide (and the full beans 48V phantom I'm sure would fry them), so I never ended up buying them. Have you tried your measurement method with any stock headphones that someone like Tyll has already done measurements for? Then we can get some idea of how well the Panasonic capsule performs.
 
Quote:

Hey guys,
 
I've also been doing measurements as I build my Thunderpants knockoffs. I'm taking a slightly different approach in that I want my cups to be hot swappable, so that I can have different damping schemes for mood/isolation/weight. And just to have fun with different enclosure types. So I'm attaching the baffles to a DT880 type swivel headband and using a strap for cups.
 
I highly recommend that you guys get a hold of Room EQ Wizard (freeware) and a Panasonic WM-61a mic capsule ($3) to perform measurements. You just solder the capsule to the end of some beaten up earbud cord, short the ring and tip on the plug, and you have an adequate microphone for measurements that will also fit in your ear (inside an ear plug). REW does the measurement sweep and deconvolution for you, and you get to see the impulse response etc. I'm able to get good repeatability with these in ear measurements, and each measurement only takes a few seconds. 
 
I want to get a damping scheme that is as close as possible to flat, according to the in ear mic, to use with binaural reproduction, and at least one more for diffuse field EQ. Maybe many more! My dad is a wood turning so I can order up different cup types and sizes.
 
As I get further along I'll post some pics.
 
I actually have a couple of technical questions for you guys as well. First up - what's a good PC oscilloscope? I want to check my square waves. At the moment I'm generating in REW, recording in Audacity, and looking at the waveform...but Audacity keeps crashing. So far I can't get the square wave to look totally flat at 30 Hz like the Thunderpants measurements at Inner Fidelity, but I can get a waveform similar to to measurement of LFFs pair. (Step rise and roughly linear fall to zero.) I'm wondering about the bass vent. In this case, the bass vent does not work like that of speaker system, right (constructive interference)? It's more like a pressure valve? In that case does the shape matter at all? Thunderpants have a single hole. What happens if that is replaced by a line with the same area (e.g. a thin circumference of felt)? And then the mathematical limit of a slightly porous cup?
 

 

 

[Twinster]

I take from your description that you take measurements with the headphone on you head and the mic inside one of the cup? That is genius. 

 That way it take your ear and seal in the equation.
 
 
 
 
 
Quote:

Hey guys,
 
I've also been doing measurements as I build my Thunderpants knockoffs. I'm taking a slightly different approach in that I want my cups to be hot swappable, so that I can have different damping schemes for mood/isolation/weight. And just to have fun with different enclosure types. So I'm attaching the baffles to a DT880 type swivel headband and using a strap for cups.
 
I highly recommend that you guys get a hold of Room EQ Wizard (freeware) and a Panasonic WM-61a mic capsule ($3) to perform measurements. You just solder the capsule to the end of some beaten up earbud cord, short the ring and tip on the plug, and you have an adequate microphone for measurements that will also fit in your ear (inside an ear plug). REW does the measurement sweep and deconvolution for you, and you get to see the impulse response etc. I'm able to get good repeatability with these in ear measurements, and each measurement only takes a few seconds. 
 
I want to get a damping scheme that is as close as possible to flat, according to the in ear mic, to use with binaural reproduction, and at least one more for diffuse field EQ. Maybe many more! My dad is a wood turning so I can order up different cup types and sizes.
 
As I get further along I'll post some pics.
 
I actually have a couple of technical questions for you guys as well. First up - what's a good PC oscilloscope? I want to check my square waves. At the moment I'm generating in REW, recording in Audacity, and looking at the waveform...but Audacity keeps crashing. So far I can't get the square wave to look totally flat at 30 Hz like the Thunderpants measurements at Inner Fidelity, but I can get a waveform similar to to measurement of LFFs pair. (Step rise and roughly linear fall to zero.) I'm wondering about the bass vent. In this case, the bass vent does not work like that of speaker system, right (constructive interference)? It's more like a pressure valve? In that case does the shape matter at all? Thunderpants have a single hole. What happens if that is replaced by a line with the same area (e.g. a thin circumference of felt)? And then the mathematical limit of a slightly porous cup?
 

 
 

 

[bluemonkeyflyer]

I'm still tweaking and testing BMF 7.  I'm making progress and what I hear is very good. I will post the configuration when it's "ready."
 
Ear side Dynamat seems to tighten the bass, improve the top end, and make the background blacker.  I don't hear any graininess. I'm using ear side Dynamat with a number of other mod components. Consequently, the sound quality and sonic signature results from the synergy of some, or all, of the mod components I have in place. Ideally, I'd like to be able to determine the relative contribution of each component. One or more might be eliminated if they add little to no benefit to the configuration.
 
As for being sure of the SQ benefit (of any mod), I don't think is really possible. I'm just one guy plodding along by trial-and-error with a unique set of ears, preferences/biases, and an audio chain different from others'. In other words, you'll never know until you try any mod component or mod configuration for yourself.
 
Quote:

me three. cotton works well when it's a thin layer. bluemonkey i eagerly wait for your BMF 7. i need sub-bass out of these. also, i know how dynamat/fatmat works in theory, but did you (or anyone else who reads this) expirience real and noticable sound quality effect? i want to be sure before i buy it.

 

 

[Twinster]

+1 for your last paragraph. Everyone has to try & tweak to their ears but obviously we all appreciate the fact that you share your researches & results with all of us.