Just listened to some Fostex T50RPs today... WOW! - Page 656

Quote:

Originally Posted by chinook9 

 

 

 

Did you use steps 1 thru 11 under "Simplified and Consolidated Pictorial for DBV #3" in the very middle of page 1 of the Incremental mods thread as your guide?  I followed these steps and I didn't need to open mine again to tune them.  They were vastly improved..

 

You should hear a significant improvement without any burn in.

 

First, if you're going to be working on these a bit, make your life a little easier by cutting out the four posts.  A set of side cutters does a decent job and then its easier to do a nice neat job of putting the cotton and fiberglas in and you won't have to fool with cutting so many slots in the cotton/fiberglas. 

 

You might need to cut the holes in the stiffened felt with a hole punch rather than just poking them in.  I made 4 6mm holes with a hole punch. My holes ended up being mostly over the magazine paper treble reflector but I still get plenty of low bass.  I also left the ear side bass vent open. 

 

Try a magazine paper treble reflector?  I used a 20 mm disk. It should improve the treble.

 

Other than what I have mentioned, I would suggest you try varying the thickness of the cotton/fiberglass.   

 

Keep us apprised of your progress.

 

everything chinook9 says ...  if you follow the recipe & use exactly the same materials identified in the recipe, then it's like shooting fish in a barrel ... bluemonkeyflyer's guide is literally foolproof.  if things sound muffled, my first guess would be an overindulgence of stuffing (cotton/fiberglass).

hth,

So in my own modded set, plugging the baffle port increased the 30-40Hz response by a couple dB. Hmm... 

Quote:

Originally Posted by SonicTheRetard 

So I bought a T50RP mod kit from Fraggler saving me a lot of cash. Thanks goes to him for that. And anyone thinking about doing these mods, he's your man if you want to save money on materials.

 

I tried following the DBV #3 mod exactly as possible. Don't know if I notice an improvement or not. I don't want to say it, but it actually sounds more muffled than it did stock. Perhaps I need more burn in.

 

What could possibly be holding back the treble? 

What tweaks can I make to DBV #3 to increase the bass? I poked 6 holes in the 40x40mm stiff felt over the driver, and used a piece of transpore tape as the treble reflector. But everything just sounds muddier than it did prior to attempting the mod.

 

Here's a photo of my mod in progress.

Since everyone is talking about specific steps, I'll just add another perspective you can probably consider. By no means am I saying this is the problem you are encountering, but just some food for thought.

DBV #3 is supposed to give you a very flat frequency response. This is opposed to having largely heightened bass or treble to account for the hearing curve. For that reason, flat frequency response can sound muffled if you're used to emphasized freq ranges (like just about every other headphone until the higher end). This, for many, sounds muffled or dull (yet sounding technically amazing).

This is spoken assuming you have the same, or similar, end result as DBV #3.

Quote:

Originally Posted by hemipowered007 

I've read through the entire thread and never heard of anyone giving a definitive answer to this question. Has anyone found out for sure that the new t20rp mkii is the same all around as the t50? Just with a different damping scheme? I know the drivers and cup size is the same. But is the magnet array the same as well? Obviously I'm going to mod these so if I can save 40 bucks and end up with the same end result that would be awesome. And thank you to everyone who's helped in this thread is been an awesome read through and I can't wait to start my ortho journey!

Nobody can answer this since nobody is sure of the answer. One source had been cited for saying all the drivers are the same, and indeed whatever is written on the driver seems to imply the same drivers. At least that is the case for the T40RPmkII. But is there more to it than those letters? we don't know. One could check if the (replacement) parts # for the T20RP mkII is the same as the T50RP. What we are sure of, is that they sound different.

As for damping scheme, I think it's more proper to say the lack of. Or something.

In any case, if you decide to try with the T20RPmkII, the info in this thread should still be highly useful although your results may vary. You're better off putting your own judgement and tastes into each step of the mods to best match your ideal. BMF's incremental mod thread pretty much shows what each implementation will do for you, you just have to apply that to whatever sound the T20RPmkII is actually providing you.

I got my T50RP and a mod kit. I have a few questions.

First off, I love the stock response of the T50RP. There are no spikes or dips - it seems to match my ears well, as do my absolute favorite phones, the K271mk2. However, something about the stock T50RP sounds wrong. I admit I'm not using good amplification yet. It isn't the lack of bass or anything. I think the response is a little humped in the middle and I'd like it to be slightly smiley-curved. Just about every mod, especially the DBV 3 here seems to raise the bass and raise the highs, making the phone flatter, but preserving that spike and dip which seem to match my ears just right. Am I on the right track here?

The first mod I did was taking the huge velour ear pads from my old phones and putting them on, along with a curved bow of plastic holding the back of the ear pad higher off of the head, so as to angle the driver a bit and move it away from the ear. This raised the treble relative to mids. I preferred this greatly over the stock flat pads.

Now, I've got SRH840 pads. They again place the headphone flat onto the head. I want to know if it is in line with the typical mod protocol to shove something between the ear side baffle and rear of the SRH840 pad to raise it off a bit?

The modding kit I have received includes clay, foam, stiff and soft craft felt, and cotton balls.

The clay provided is SCULPEY Bake Shop oven-bake clay. It is however listed as non-hardening (until baked). I assume this is okay based on what I'm reading. Please let me know if I should avoid it and aim for normal plasticine.

The silverstone foam, soft craft felt and stiff craft felt are all self-adhesive backed. The stiff felt is about 2mm thick. The adhesive back is also not very permeable to air; the adhesive seems to be a nice uniform layer. Blowing air through it manually produces little permeability for the stiff felt. The soft felt has much more (but of course restricted) permeability. If I stick it over the rear of the driver, won't that effectively create an airtight seal? Is this what is desired?

Is this the same type of adhesive-backed felt being used for the driver by everyone?

Edit: I see this felt isn't suitable for DBV 3 and I need regular felt with double sided tape.

Quote:

Originally Posted by k00zk0 

I got my T50RP and a mod kit. I have a few questions.

 

First off, I love the stock response of the T50RP. There are no spikes or dips - it seems to match my ears well, as do my absolute favorite phones, the K271mk2. However, something about the stock T50RP sounds wrong. I admit I'm not using good amplification yet. It isn't the lack of bass or anything. I think the response is a little humped in the middle and I'd like it to be slightly smiley-curved. Just about every mod, especially the DBV 3 here seems to raise the bass and raise the highs, making the phone flatter, but preserving that spike and dip which seem to match my ears just right. Am I on the right track here?

 

The first mod I did was taking the huge velour ear pads from my old phones and putting them on, along with a curved bow of plastic holding the back of the ear pad higher off of the head, so as to angle the driver a bit and move it away from the ear. This raised the treble relative to mids. I preferred this greatly over the stock flat pads.

 

Now, I've got SRH840 pads. They again place the headphone flat onto the head. I want to know if it is in line with the typical mod protocol to shove something between the ear side baffle and rear of the SRH840 pad to raise it off a bit?

 

The modding kit I have received includes clay, foam, stiff and soft craft felt, and cotton balls.

 

The clay provided is SCULPEY Bake Shop oven-bake clay. It is however listed as non-hardening (until baked). I assume this is okay based on what I'm reading. Please let me know if I should avoid it and aim for normal plasticine.

 

The silverstone foam, soft craft felt and stiff craft felt are all self-adhesive backed. The stiff felt is about 2mm thick. The adhesive back is also not very permeable to air; the adhesive seems to be a nice uniform layer. Blowing air through it manually produces no permeability. If I stick it over the rear of the driver, won't that effectively create an airtight seal? Is this what is desired?

 

Is this the same type of adhesive-backed felt being used for the driver by everyone?

 

Edit: I see this felt isn't suitable for DBV 3 and I need regular felt with double sided tape.

k00zk0,

mrscotchguy used non-drying bake to harden clay and it melted his cups and baffles. I'm not sure of the brand he used, but it may have been Sculpey.  Get some plasticine if you can't get Newplast.

Soft or "limp" felt does not have self-adhesive backing. Don't use any self-adhesive felt on the back of the drivers or over the internal cup vents because it's impermeable and will "choke" your driver and cup venting - killing your sound quality. Get some non-adhesive stiff felt from a craft store like Michael's, instead. You can use the self-adhesive felt on the center cup floor above the central headband hanger screw compartment and below the internal cup vents.

Silverstone is a substitute for Paxmate Plus but neither is a substitute for Acoustipack Lite.

If you're going to try DBV #3, go to Post #1 in Incremental Mods and Measurements, scroll down past Graph #55 to "Simplified and Consolidated 'Tutorial for DBV #3" and "Pictorial for DBV #3" for instructions and photos about preparing Rite Aid "First Aid Rolled Cotton" and implementing the config. "First Aid Rolled Cotton" works better than cotton balls for me and it is a good substitute for Rite Aid "Natural Absorbent Cotton" (that's no longer available). You cannot use it right out of the box because it's too dense and matted. Separating each of its 40 individual layers, re-stacking 15 layers, trimming, and cutting = 2x7x7 cm is a good starting point for your initial build. See "Tuning Rules of Thumb" that follows the DBV #3 Pictorial for suggestions about how to tweak for your desired FR.

Thank you bluemonkeyflyer!

I actually was mistaken. The felt adhesive is permeable. The soft felt has adhesive and is definitely limp, and when tested by pressing lips to the adhesive and blowing air, quite a lot of air flows through. The hard stiff one is also permeable but is very resistant to air going through it. There are visible tiny randomly spaced holes in the adhesive backing.

This specific mod pack was obtained from Mayflower Electronics and as such I assume it's somewhat safe.. He provides his own powerpoint on how to mod the phones:

What do you think of this mod?

https://docs.google.com/file/d/0B6IxqGzcxDWTT2VsTklVN2lWbFU/edit

Attribution: ODP document wouldn't open in anything but openoffice.org so I've converted to ppt and uploaded on google docs (hope you don't mind, mayflower).

Quote:

Originally Posted by k00zk0 

Thank you bluemonkeyflyer!

 

I actually was mistaken. The felt adhesive is permeable. The soft felt has adhesive and is definitely limp, and when tested by pressing lips to the adhesive and blowing air, quite a lot of air flows through. The hard stiff one is also permeable but is very resistant to air going through it. There are visible tiny randomly spaced holes in the adhesive backing.

 

 

This specific mod pack was obtained from Mayflower Electronics and as such I assume it's somewhat safe.. He provides his own powerpoint on how to mod the phones:

 

What do you think of this mod?

 

https://docs.google.com/file/d/0B6IxqGzcxDWTT2VsTklVN2lWbFU/edit

 

Attribution: ODP document wouldn't open in anything but openoffice.org so I've converted to ppt and uploaded on google docs (hope you don't mind, mayflower).

The adhesive on the felt will over-dampen the drivers and cup vents, tiny holes or not.  You could try it, though. Maybe it will work for you. Be careful of adhesives applied directly on the back of the white driver material. Some adhesives react with and "liquify" the stock adhesive that secures the white material to the back of the driver.

Quick question as I prepare to mod my T50RPs. Can you use Blu Tak instead of modeling clay? Is there any reason not to? I have a ton of Blu Tak in the house and figured I might as well put it to good use.

Quote:

Originally Posted by Vidmaven 

Quick question as I prepare to mod my T50RPs. Can you use Blu Tak instead of modeling clay? Is there any reason not to? I have a ton of Blu Tak in the house and figured I might as well put it to good use.

I don't know about the reliability of the data HERE (Corrected) so take it FWIW. Scroll down to next to last section.  If accurate, plasticine is about twice as effective as blu-tak. Newplast is about 4 times better than blu-tak and twice that of plasticine.

There is a new product for sale in this link but I've not tried it. 

Quote:

Originally Posted by Vidmaven 

Thanks for the quick response. The first link is the same as the second link.

Sorry 'bout that! LOL I corrected the link.

HERE it is.

Thanks for all the replies guys. I will make those adjustments and come back with the results.

Seems like BMF has revised some sections in the Incremental Mods post, added more pictures, and that's definitely going to help me. Cheers to you BMF.