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[DIY Project] Pioneer SE-700RP: T50RP drivers --> Pioneer SE-700 (56k don't even try)

post #1 of 24
Thread Starter 

Yeah yeah, I know I'm pretty infamous for putting down all the T50RP mods and modders on this forum, and I'm probably going to get a lot of shıt for posting this. However, I have three SE-700s sitting around, one of which doesn't work at all, and I need to get rid of them. Rare as it is, I knew a non-working one wouldn't fetch much on eBay, and it'd be a shame to throw away such a nice looking shell. Then I remembered that my friend sent me a T50RP a while ago as a gift...

 

 

So, I completely disassembled the T50RP, removed the SE-700's pretty piezoelectric films, and started working.

 

 

To see if there was any potential in this endeavor, I just wanted to try the bare driver at first. I set it in horizontally and it seemed to fit well. However, I ran into an issue...

 

 

These damned round screw holes got in the way when I tried to close the headphone. So I turned it vertically...

 

 

... and it was just barely too large to fit on the piezo driver shock mounts. And the screw holes were still keeping me from closing it.

 

 

I had wanted to keep this mod reversible, but I guess that's out the door. Glad I grabbed a hack saw.

 

 

I cut away the screw hole on the top and that did the trick. Now it fits, and there's a small amount of the screwhole still there so it should fit back in the T50RP shell if need be.

 

 

However, if I close the cup the driver rattles around inside the casing. I'll need something to hold it in place.

 

 

Turns out the pieces of yellow foam used to tension the SE-700's diaphragm provide just enough pressure to hold the driver in place. So I stuck those in there and closed it all back up, and the driver stays put. Note that I've only done all this this to one side thus far. 

 

 

Sound is... well not so good. Immediately I hear a really gross-sounding resonance in the midrange, almost certainly caused by the gap between the driver and the baffle plate. Couple that with piss-poor bass, a complete absence of treble, and a very harsh sound and you get quite an unpleasant listening experience. However, it does sound considerably better than the stock RP at this point, so I'm going to continue with this mod. I'll report back on this thread as I continue to try new things. 

 

Cheers!


Edited by takato14 - 8/30/13 at 10:51am
post #2 of 24
Thread Starter 

I knew right away that the first thing I needed to fix was that disgusting resonance, so I popped the headphone back open and removed the driver. 

 

 

As mentioned before, I suspect that the resonance is caused by the gap between the front of the driver and the casing. There were these thin foam squares left from the stock RP which were on the ear side of the drivers, I assume to absorb some resonances and keep the drivers from rattling around (like I need to do). However, they're too thin to use for this shell. 

 

 

I went into my room and dug out my box of raw materials; I remembered that I had this big chunk of foam left over from an old carrying case. This should work well to dampen that resonance.

 

 

I was about to trace the shape of the foam squares onto the thicker foam when I realized that it doesn't touch the edges of the RP driver due to the plastic rim on the stock shell's baffle plate. So instead I needed to trace the ear side of the driver onto paper and make a stencil.

 

 

Hnnghh...

 

 

No worries, I just set the driver under the paper and creased the edges. 

 

 

Now I have a stencil.

 

 

Here's the foam piece cut out...

 

 

... and here it is mounted into the headphone. The driver now rests on the foam instead of the shock mounts.

 

 

The driver still rattles around since the back is plastic-on-plastic, so I need something to cushion it. The yellow foam pieces from the SE-700 are actually three separate sheets sandwiched together, so I took the thinnest one and stuck it behind the driver. 

 

 

Like so. 

 

Sound? well.. the resonance is gone... sort of :x

 

The bass is way overcooked and hot, and there's so much midbass emphasis that it's truly disorientating. I think what I did was move the resonance lower, instead of removing it. Plus, there's still no treble to speak of, making it very dark sounding and edgeless. Looks like that black foam isn't going to work well after all. 

 

Onto plan B...


Edited by takato14 - 8/29/13 at 10:45pm
post #3 of 24
Thread Starter 

Since the black foam was a bust, I took that out and pondered for a bit. What I needed was to dampen the resonances on the baffle plate without obscuring the driver so much that it muffles the sound, and without creating an air chamber for sound to bounce around in. I also needed adequate backwave dampening to keep the bass in check. The yellow foam from the SE-700 seemed to do the latter quite well before, so I started with that. 

 

 

I took the thinnest sheet and placed it over the baffle plate. This should be enough to absorb those nasty reflections from the driver.
 
 
 
The driver now sits on the shock mounts for the piezo films again.

 

 

I also stuck in a reflex dot made of blutak. Hopefully this will help get rid of that nasty dark signature by punching up the treble/upper mids. 
 
 
Sandwiched together...
 

 

...and assembled. 

 
Put them on... and one channel is completely silent. wat.
 

 

The hell did I...
 

 

wait...
 

 

... did I SERIOUSLY forget to strip the wire before I soldered it. 
 
Well, I needed to wire the headphone up properly anyways I guess. I desoldered the wires and took apart the headband.
 

 

Stuck on the strain relief for the SE-700 (which I had forgotten before) and pressed the wires into the crevices of the shell, as the design intended. 
 

 

After several attempts I managed to get the ******* wire though the headband. Stupid thing.
 
 
And now it's reassembled nice and clean. Gah. Now that that's out of the way, how do they sound?
 
The overall tonal balance is relatively neutral, with a somewhat abrupt bass rolloff. I can already tell my next priority is getting that low bass back up. The upper mids have been punched up enough, but the treble is lacking real extension, so I'll have to figure out a way to get that upper treble too. 
 
 
The SE-700 was an uncomfortable bastard before, and since this mod basically doubled the weight of the headphone due to the drivers, its gotten to the point where wearing them is unbearable. I recalled that AKG pads were about the size of the SE-700's earcups, so I grabbed my pair of pleathers from my K240 S and sandwiched them between the cups and my ears just to see if it'd be feasible to use those instead.
 

 

Dear God. Now I see what people were getting at when they said "world class" could describe a modded T50RP. Now, don't get ahead of me. This is still not world class sound by any means. It is however quite impressive. Now, with just a change of pads, they sound extremely flat and exciting, perhaps a bit tilted to bright. Great attack, good decay, wonderful treble extension, very tight imaging, and a good-sized soundstage. Very airy and sparkly. The bass, however, has been taken back down to what it was before. That is to say, lacking in extension and presence. Gotta see about getting that bass back up.  A less pressing issue with it right now is that the highs are a little bit hot and fatiguing, probably solvable with some mass loading to tame the peaks in the treble.
 
More to come!

Edited by takato14 - 8/30/13 at 10:57am
post #4 of 24
Thread Starter 

 

Before I start working on getting the bass back up, there's an... issue I need to attend to first.

 

1000

 

I need a way to mount these pads to the SE-700. I recalled a mod I performed a while ago for my Audatron SH-608Rs that let me put AKG pads on them. 

 

 

It just so happens that the top of a Philadelphia Cream Cheese container is exactly the same size as the pad mounts on AKG headphones. Who knew?

 

 

Previously, I had cut the white rings off the top of the containers and stuck them onto the sides of the Audatron's earcups.

 

 

...but as you can see, that won't exactly work here. There's no side to attach them to. 

 

 

After a bit of thinking I lined the rings up with the SE-700's cups, marked the places where the plastic was raised for the strain reliefs and yoke mounts, and cut them out with an X-Acto knife.

 

 

Then I covered the bottom edges of the rings with poster putty. Hey, I was out of epoxy, sue me.

 

 

I pressed the rings onto the SE-700's cups and "rubbed" it in until it was relatively flat and I was sure that they were securely attached.

 

 

I then wrapped black electrical tape around the white and blue area to make it look nice. Well, nicer at least.

 

 

And now the pads can be mounted to the SE-700. I'm thinking of trying velour AKGs (as seen on the K272HD) to see if it breathes better, but other than that, they're pretty comfortable now.

 

 

...But not comfortable enough for me. Plus, my brother had an old backpack lying around, just waiting to be sacrificed.

 

 

I cut one of the straps off, fit it to the inside of the SE-700's headband, and pinned it down. This will be similar to the comfort strap for the stock T50RP.

 

 

I hand-stitched it to the existing band using a two-thread technique commonly seen in modern sewing machines. No WIP shot for this because it was far too tedious and irritating.

 

 

And now it's comfortable. Please excuse the purse; its my mom's.

 

The old pads are still on, and might stay that way if I can't find a way to take them off without destroying them (this is the first SE-700 I've seen that actually has the leather on the pads in tact). However, they are covering the sides of the driver a bit, so it might be worth my while to sacrifice them. I'm going to work on that bass at a later time; it's late again.


Edited by takato14 - 8/31/13 at 6:34pm
post #5 of 24

Haha, nice. I've done a few T50rp transplants myself. I have links in my sig/profile if you want to take a look.

post #6 of 24
Thread Starter 
Quote:
Originally Posted by Armaegis View Post

Haha, nice. I've done a few T50rp transplants myself. I have links in my sig/profile if you want to take a look.

Yeah, I've seen some of them. Quite impressive what you've managed to squeeze these drivers into, they're much bigger than they look in pictures...


Edited by takato14 - 8/28/13 at 11:49pm
post #7 of 24

My first thought is to use some putty to hold the driver in place instead of that sponge. Shove a piece of felt in front of the driver, and some proper acoustic foam on the cup wall behind the driver.

post #8 of 24
Thread Starter 
Quote:
Originally Posted by Armaegis View Post

My first thought is to use some putty to hold the driver in place instead of that sponge. Shove a piece of felt in front of the driver, and some proper acoustic foam on the cup wall behind the driver.

I have a few things in mind as far as driver mounting goes, this was just a test to see if the effort was worth it. I'll work on this some more tomorrow, its past 3 AM here...


Edited by takato14 - 8/29/13 at 12:11am
post #9 of 24
Thread Starter 

More progress.

post #10 of 24
Thread Starter 

More progress. Check the first page. Bump.


Edited by takato14 - 8/29/13 at 10:52pm
post #11 of 24
Thread Starter 

Bump? :<

post #12 of 24

Wow, those are some really nice shiny shells! great job.

post #13 of 24
Thread Starter 

More progress.

post #14 of 24

Loving the animated GIFs biggrin.gif

Interesting progress.

post #15 of 24

Quite an interesting "Franken-phone" you have here! Keep at it for us.

:popcorn:

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