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Just listened to some Fostex T50RPs today... WOW! - Page 349

post #5221 of 10609
Quote:
Originally Posted by RexAeterna View Post

well seems like combination of fiberglass and polyfill works best for me. the fiberglass does all the absorption while the polyfill adds more ''space'' so to say to make the driver believe it's in a larger enclosure improving imaging,dynamics and soundstage.


I did see acoustic Earth Wool for walls at the hardware store, couldn't get a sample though, bummer, want to try it. I think it will be heaps better than cotton and it doesn't itch like fiberglass.

post #5222 of 10609

Guys, I'm confused on a few things, why do we add clay around the driver?  Wouldn't the engineers have taken driver vibration into account when designing the baffle?  Why would any engineer leave a vibrating driver in a baffle?  Invites all sorts of QC issues.

post #5223 of 10609
Quote:
Originally Posted by HDMan View Post



I did see acoustic Earth Wool for walls at the hardware store, couldn't get a sample though, bummer, want to try it. I think it will be heaps better than cotton and it doesn't itch like fiberglass.

wool will work as well as fiberglass. just cost bit more. i actually don't get itchy from touching fiberglass. i know it's bad to do so but i just wash my hands after i'm done using it and since i used it on my headphones and i was touching all over it i cleaned with some rubbing alcohol before each testing. fiberglass and mineral/rock wool usually much better absorbers than the acoustic foam people been buying and that dynamat(did i spell it right?). also don't have to worry about a permanent mess like dynamat since fiberglass and mineral/rockwool is completely reversible.
post #5224 of 10609
Quote:
Originally Posted by sphinxvc View Post

Guys, I'm confused on a few things, why do we add clay around the driver?  Wouldn't the engineers have taken driver vibration into account when designing the baffle?  Why would any engineer leave a vibrating driver in a baffle?  Invites all sorts of QC issues.

 

Got to keep the price for parts to a minimum, and maximum returns for the share holders mate.
 

 

post #5225 of 10609
Quote:
Originally Posted by sphinxvc View Post

Guys, I'm confused on a few things, why do we add clay around the driver?  Wouldn't the engineers have taken driver vibration into account when designing the baffle?  Why would any engineer leave a vibrating driver in a baffle?  Invites all sorts of QC issues.



By that logic, why didn't they put any damping in the cups?  At least something minimal like they used in the T20v2.  It boggles the mind really, why all these companies made brilliant drivers and then just through them into whatever enclosure looked kinda snazzy and would stay on their (earless) manican head without falling off. 

post #5226 of 10609

It's obvious they put some thought into the cup, what with it's bass ports and all.  Seems like a lot of disjointed good ideas from different departments patched together then approved by some incompetent person, incompetent at least as far as audio goes.  

post #5227 of 10609
Quote:
Originally Posted by kingoftown1 View Post

I'm in the same situation except with the HD600.  Not entirely sure whether or not I should be buying one.
 

 


IMHO, no.  Never use my 650s.  Still use the LCD2, but it's not often my first pick.

post #5228 of 10609

Man after applying that Response stuff, these isolate probably better than headphone I have herd, which isn't alot, but they cut alot of noise out now.

post #5229 of 10609

Quick question for this weekends mods - is there any reason to keep the posts with the rubber feet on them (which sit on back of baffle) in the cups?

 

This would make it much easier to line the cups...

post #5230 of 10609
Quote:
Originally Posted by drez View Post

Quick question for this weekends mods - is there any reason to keep the posts with the rubber feet on them (which sit on back of baffle) in the cups?

 

This would make it much easier to line the cups...



I took mine off, it was Fostex's lame attempt at controling vibration. A dynamat and foam combo should do the trick over the whole cup.

 

I found some Sound screen Acoustic fibreglass, tommorrow I will take out the old plasticine from the baffle and replace it with Response Sound Deadener, and replace the cotton wool with the fibreglass. I would have to say this will be the final mod.

 

On another note, I noticed the pad risers must be high enough to give the angle, if there not high enough you will have a harsh midrange, these are my personal findings.


Edited by HDMan - 12/2/11 at 1:53am
post #5231 of 10609

Yesterday was an early Christmas, as when I returned home from work a package sat upon my porch.  Carefully opening revealed a present from from Santa LFF - a brand new set of Paradox T50RP headphones!!!

 

I will most a more complete review in a few weeks when I've had more time to listen to the Paradox's.  However, last night I used them to listen to the Cowboy Junkies Trinity Sessions Revisited.  This is a CD I have listened to many many times.

 

I only have one thing to say about the Paradox's:  HOLY SH_T!!!!  These are without a doubt, the clearest most resolving headphones I have ever heard.  Although I've listened to this CD dozens of times with my HD580's, K701's as well as Grado RS-2 and from my speakers, I am hearing sounds I have never heard before -- the intake of breath, subtle nuances to the decay of cymbals, etc.

 

In addition to sounding crystal clear (I can think of no better way than to say the headphones simply get out of they way of the music), they are very comfortable.  Most likely due to the large suspension band, after a few minutes on my head, I forget that they are even there.

 

Fantastic job Luis, just fantastic!!  I could not be happier.

 

More to come in a few weeks. . .

 

-Tim

post #5232 of 10609

I have no company design knowledge and no mechanical engineering training, only an observation and an opinion. The 4 posts inside the cups are capped with rubber shock absorbers. The shock absorbers line up with the 4 driver "nibs" and make 'controlled' contact with one another once the baffle is re-attached to the cup.  This looks like a very clever design that minimizes vibration cross talk, so to speak, between the baffle/driver assembly and the cup assembly, both contributing to the sum total of vibration and resonance.  The stock shock absorbers may also provide structural support that further limits the amount of movement generated by low frequencies. Cutting them out is not reversible, is it?

 

It would be interesting to measure a stock set and an a modded set with and without the rubber shock absorbers in place. They can be glued back on. 

Quote:
Originally Posted by HDMan View Post



I took mine off, it was Fostex's lame attempt at controling vibration. A dynamat and foam combo should do the trick over the whole cup.

 

I found some Sound screen Acoustic fibreglass, tommorrow I will take out the old plasticine from the baffle and replace it with Response Sound Deadener, and replace the cotton wool with the fibreglass. I would have to say this will be the final mod.

 

On another note, I noticed the pad risers must be high enough to give the angle, if there not high enough you will have a harsh midrange, these are my personal findings.



 

post #5233 of 10609
Quote:
Originally Posted by HDMan View Post

I found some Sound screen Acoustic fibreglass

what? i never heard of that before. i suggest just going for plain fiberglass you can find at local home dept/hardware store. the whole ''acoustic'' thing will make you pay much more. i mean unless you have to get then of course go ahead. does the screen come in layers? so you can experiment on thickness cause it all depends on thickness on how low of frequency you want completely absorbed make sure to add other stuff as well if you want to give the driver an ''illusion'' to believe it's in a bigger enclosure. that will increase the openness of the sound and give better imaging results and micro-detail extraction.
post #5234 of 10609


@Dogwan - where did you buy the sponge material? I think I remember reading your posts. I've had a cursory look at the supermarket before but didn't really find what I was looking for.

Quote:
Originally Posted by dogwan View Post

I think I can safely say that my experience was very similar. I used a spray on sound deadener inside the cups and used some natural cellulose sponge material tight up against the driver to dampen it.



 

post #5235 of 10609

I have finished for good, at least on the insides. I could always try different pads, but this configuration is months of tweaking, adjusting, listening, testing etc. I have now come to the conclusion that I cannot go any further and sound is as good as I can get it.

 

Bass is tight, clean, thunderous, impactfull and firm.

Midrange is smooth and detailed.

Treble is crisp, very detailed and extremely pleasant on the ears.

Soundstage, details, imaging and speed are better than I have heard previously.

 

I call it the:

 

 

T50 ResPonse.

 

 

Materials required:

 

Cable

4 core Mic cable

1/4 connector

Heatshrink (2 sizes)

Soldering Iron

Resin core solder

 

Cups

Respone (super sound deadener)

or

Dynamat and Paxmate (combo layers)

Insulation fibreglass (Rockwool, mineralwool etc), the acoustic version.

Cotton wool or polyfill.

Electrical tape

Drill

 

Headband

Leather or Vinyl

Elastic string

 

Pads

Shure 840 pads

Plastic food container (100mm diameter)

 

Instructions:

 

1. Peel off the pads

 

2. Unscrew the cups (the screws on the outside rim)

 

3. Completely remove the felt on the front and the back of the drivers

 

4. Cut the headphone wires off of the drivers.

 

5. Remove the little box that had the wires soldered to it on the left cup, this is a little tricky, I used an old soldering iron to melt  the plastic away. Also remove the rubber feet on the posts.

 

6. Drill a hole big enough to tightly fit 2 of the stripped wires for the new cable, you most probably will drill this on the bottom of the cups and to the front a little.

 

7. Cut to fit Dynamat (and Paxmate) or Response and line the cups fully, pressed down tight against the back of the cups. (You may want to layer the Paxmate over the top of the Dynamt first before applying). Also be carefully not to layer it over the edge or the rim, were the baffle will press down into place (after application there should be a ring of vacant space around the edge of the cup) otherwise pressing the baffle down may prove troublesome. Also you may want to cut the bottom vent stripe open at this point, it could also be done at the end from the outside with a blunt nail file, this will allow the driver to breath and the bass to open up.

 

8. Fill all the holes/gaps around the driver on the baffle, with Response or dynamat then paxmate.

 

9. Cut an oval shape of acoustic grade fibreglass insulation, about 15mm thick, enough to fill the centre of the cups only. Also apply a very thin layer of cotton wool over the fibreglass (facing the driver). This will have to be adjusted to how you prefer, bass and midrange response.

I found that, more fibreglass equals less bass with smoother mids and treble, less fibreglass equals more bass and in your face mids and treble.

 

10. Heat the soldering gun up (20w is for PCB boards), melt some solder first, then apply to the driver to remove the old wires, using a suction gun or tape, remove the old solder.

 

11. Strip the cable down the middle about 40cm, exposing the 4 wires. Use white for Left, red for Right and use the 2 remaing wires for negative/ground. Apply heatshrink. Solder the the 1/4 connector on the other end, Left is the smallest tab, right is bigger and the 2 negative/ground wires get twisted together and soldered to the outside tab.

 

12. Pull cable through the hole of the cups and tie a knot in the cable AFTER you have pulled it through the cups, this will stop it from being pulled out once assembled, then solder to the drivers (heat solder onto the gun and dab onto the wire while holding it onto the driver).

 

13. Assembly time, place the fibreglass/cotton fill into the centre of the cups and carefully pull the cable back through the cups while moving the baffle over into position. Tighten the screws down, if the baffle isn't going to close down porperly you might thread the screw holes.

 

14. Line the earside of the cups with Response or Dynamat then Paxmate (leave holes for the outside screws and the tiny little vent hole on the corner of the driver. (optionally you can also tape the rim of the baffle for extra air tightness)

 

15. Peel back the 840 pads and roll them on. Get some electrical tape and pull the rear side of the pads out enough so they are just on the edge about to fall off, then tape them up (keep the front of the pads in the normal position), this will allow the necessary room for the plastic risers.

 

16. (I came up with this one, neat little trick) Plastic risers, cut the food container in half down the middle. With one half, cut a tapered shape, 28mm in the centre and 15mm at the ends (at the ends cut them in a circle shape so you don't have any sharp edges to cut the pads up). Line the insides of the risers with Response or dynamat then paxmate. It is essential that the risers are exactly 28-30mm, any smaller and your going to get a harsh midrange, on any T50RP with 840 pads.

 

17. Insert the risers into the back of the pads by gently pulling the pads out.

 

18. For the headband, you can cut out a shape as you desire for your head and tie it onto the bottom of the headband with elastic string.

 

 

Notes:

 

1. You may find it easier to only solder one driver, then assemble, as the other driver won't be left hanging and pulling.

 

2. The bass vent may have been covered by the fibreglass, be sure to get a blunt nail file and bore it out from the outside, so the driver can breath, this will make a huge difference to wether or not you have bass or not.

 

P.S.

 

I have also dedicated a thread (with pictures) to this configuration for easy access, nothing like weeding through 5000 posts to find it.

 

http://www.head-fi.org/t/583371/t50-response#post_7938001


Edited by HDMan - 12/3/11 at 1:36pm
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