Miracles in Audio, by luck, by good choices,by design or by tweaking...


I owned a low cost headphone for many years, the Fostex TH7B, first version( a new one close version exist Fostex TH7BK), semi-open headphone...I was never completely satisfied by any headphones I ever owned: Hifiman 400, Stax basic lamda, Stax 5 gold,Akg 340,Akg 701, beyerdynamic 990, and T150... Because in each of them with all their qualities I never listen to at the same times, a confortable headphone with natural timbre and voicing, with a good imaging and a realistic soundstage(not too close to my ears)...


For the last days I tweaked this Fostex, to damp his internal resonance I used sorbothane, I put some shungite stones at the exterior part of the cups and I use some Herkimer diamond in the interior pads( 3 at 120 degree) … Now this low cost headphones crush all my others if I sum all his qualities... For example his mids and voicing cannot beat the AKG 340 but among all my other headphones it is the best that is near that mids and it is more confortable, and with longer cable than the 340...His imaging is better and more realistic than the 340 etc etc...It is the same if I compare with the others...


His most important qualities is natural timbre and clear imaging,very precise pinned point accuracy and natural, so clear it crush for that ALL the others to dust...In the French audio circle the reviews were more than very positive few years ago...Diapason d’or and choc Classica...I am not the only one impressed buy the ratio quality/price... But remember that thesae reviewers dont tweak their headphone...The difference between before and after the tweaks are staggering...


Yes Miracles happens in Audio: cost is under 100 American dollars... Few years ago they cost me 50 bucks new... I never dreamed that I will go back to headphones...


I will enjoy your miracles stories of any kind ….My best to all...
128x128mahgister

Showing 1 response by edstrelow

I can certainly see why you would like the effects of adding sorbothane to headphones.  I have been pointing this out for some time.   https://www.head-fi.org/threads/damping-mechanical-energy-distortion-of-stax-and-other-phones-with-sorbothane-and-other-materials.744839/

If you check my later posts in that thread you will find that I report that the type of sorbothane, size and manner of fastening make a large difference. In brief,   you want to use small pieces of dense (70 duro) sorb. Fastening is tricky, my best results are using a Lord commercial glue recommended by Sorbothane but which is expensive, and has a short shelf life after being opened.  

The theory of sorbothane is that it gets rid of vibrational energy by converting it to heat.  Probably all the vibrational energy  in your phones or speakers  ends up as heat in a fairly short period of time (milliseconds possibly.) The problem  for audio, I suspect is that this doesn't normally happen quickly enough,  so that this energy sits around in your headphone or speakers system long enough to end up back in the drivers, messing up the sound.    I see many suggestions that this energy causes the walls earcups etc to vibrate making audible sound.  I find this unlikely for most frequencies because wooden/plastic/metal cabinets or earcups  are going to need a massive amount of energy to start behaving like speakers themselves so as I say I think the problem is the energy messing up the drivers. 

 The discussion in this thread quickly shifted to the use of crystals which I have never tried.  But I do not understand what the physical principles are supposed to be operating here.