[WoodyLuvr]

I recently decided to “freshen up” my old pair of Sony MDR-570LP. They are nothing special, sound wise, but I always like their “retro” look and lightweight design.


Out of the box, they sound muffled, mostly because of pad's design.
The foam ring is connected to the baffle by double-sided adhesive tape and then coated with perforated faux leather.



Here we can see stock tuning. It's very simple, in a good way of course

MDR-570LP's are labeled as closed back headphones, but still they have large rear vents behind black foam filters.
I noticed they are lucking a bit of bass, and I was planning to try GRADO pads, so I made two small filters with a 2 mm hole to reduce airflow.
Also to reduce parallel reflection of back sound wave, I placed a little piece of “sandpaper tape” right behind the driver bass port which has the role of a diffuser.


Next, the fun part. This is the basic acoustic treatment of the cup.
First, I filled big pockets of the shell with TRULEX cloth.
Also, I replaced the black foam filter on baffle vents with porous foam and add mass loading on the back of the driver.


The rest of the exposed plastic area is covered with felt, and I sealed the small cable hole with Teflon tape.
BTW ... cable is nice and soft and I decided to leave it as it is.


These are some tuning filters which I tried.
At the end, I combined several filters into one “sandwich” filter.


The sound without filters is too bright, with “thin” sounding vocals and no bass.
For “sandwich” filter, I used foam pads, added a piece of perforated fabric and felt which also symbolize left and right side.
White tuning paper (Y3) covers center hole on driver grill.


And this is the final look.

A stellar mod, well done!!! Really good to see that you salvaged this meh sounding headphone model... probably improving the sound immensely I am betting.

How does it sound? Was the bass issue solved? If not quite what you wanted sound wise please do consider reducing/increasing mass loading and/or repositioning the dampening material into different positions/patterns as that sometimes can have a dramatic effect on the sound signature (tuning) especially the lows (bass) and lower mids (midrange).

FYI - MimiMamo makes some interesting stretchable slip covers that will fit the 570 here. I know some modders like to use them for their projects, especially for quickly testing different filters.

The 2009 Sony MDR-570LP is a pseudo re-release of the 1994 Sony MDR-CD570 which used quite a powerful neodymium magnet back in the day (perhaps a N55 or earlier variant of). I hadn't realized that the 2009 Sony MDR-570LP was a beast in the input power department... capable of handling 1W! Very good for a middle tier headphone at this price range.

Sony MDR-570LP
■ Released ~November 2009
■ Model Sealed Dynamic Type (closed; supra-aural)
■ Diaphragm 30mm Dome type
■ Impedance 24Ω
■ Reproduction Frequency Band 12-22,000Hz
■ Allowable Input 1,000mW
■ Sensitivity 105dB/mW


Sony MDR-CD570

■ Released ~November 1994
■ Model Sealed Dynamic Type (closed; supra-aural)
■ Diaphragm 40mm Dome type
■ Impedance 40Ω
■ Reproduction Frequency Band 5-30,000Hz
■ Allowable Input 500mW
■ Sensitivity 106dB/mW

 

[furyossa]

A stellar mod, well done!!! Really good to see that you salvaged this meh sounding headphone model... probably improving the sound immensely I am betting.

How does it sound? Was the bass issue solved? If not quite what you wanted sound wise please do consider reducing/increasing mass loading and/or repositioning the dampening material into different positions/patterns as that sometimes can have a dramatic effect on the sound signature (tuning) especially the lows (bass) and lower mids (midrange).

FYI - MimiMamo makes some interesting stretchable slip covers that will fit the 570 here. I know some modders like to use them for their projects, especially for quickly testing different filters.

The 2009 Sony MDR-570LP is a pseudo re-release of the 1994 Sony MDR-CD570 which used quite a powerful neodymium magnet back in the day (perhaps a N55 or earlier variant of). I hadn't realized that the 2009 Sony MDR-570LP was a beast in the input power department... capable of handling 1W! Very good for a middle tier headphone at this price range.

Sony MDR-570LP
■ Released ~November 2009
■ Model Sealed Dynamic Type (closed; supra-aural)
■ Diaphragm 30mm Dome type
■ Impedance 24Ω
■ Reproduction Frequency Band 12-22,000Hz
■ Allowable Input 1,000mW
■ Sensitivity 105dB/mW


Sony MDR-CD570

■ Released ~November 1994
■ Model Sealed Dynamic Type (closed; supra-aural)
■ Diaphragm 40mm Dome type
■ Impedance 40Ω
■ Reproduction Frequency Band 5-30,000Hz
■ Allowable Input 500mW
■ Sensitivity 106dB/mW

Thanks Mr Woody.
The stock sound is balanced with narrow stage, with 30% of clarity.
As I mentioned earlier, the problem causes bad designed pads. I also tried to replicate similar concept (3rd example) on other on-ear model and I got the same result—muffled sound.

I also tried several combos with different type of filters. The best result I achieved by adding just pads foam and blue perforated cloth. The worst case was with KN95 mask, which surprised me the most. This mask has 3-4 different layers with different density, and they very little affect the sound. When I combine them all, sound is too thin and harsh.
Mass Loading don't have any significant impact on the sound here.

I managed to return the quantity of the bass like on stock, with 99% of clarity and zero resonance.
Also, overall sound is more spacious because Grado Pads, but at the end of the day, Koss KPH30i is far away superior.

 

[WoodyLuvr]

Thanks Mr Woody.

Mass Loading don't have any significant impact on the sound here.

Interesting, must be a weak-ass driver to be so unresponsive like that in regards to loading and dampening. Happy that the filtering worked!
Nonetheless, awesome mod... enjoy! Cheers,

 

[dougms3]

I recently received the k99 540 ohm 40mm blue empress driver.

It sounds pretty good but is lacking in bass.

Any recommendations on how to increase bass and warmth?

 

[Roderick]

What kind of housing you use? It might be better to work with the housing instead of the driver.

If you want to mod the driver try lifting the white paper around the magnet. Should be doable with a surgical knive. Expose just enough to some air to pass through. Few millimeters should be enough. If it sounds better you can poke a small hole on the paper. If it sounds worse just put the paper you lifted back in place. For holes you can start with large needle. Then make more or larger holes until you've reached preferred bass quantity. If you make several holes try to make them parallel. All holes on one side might make the driver rock unevenly because of uneven airflow.

If you made holes and changed your mind you can close the holes with tape or something. However depending on material you use on sealing the hole you might not get exactly back where you started and you might also have to repeat the operation with untouched driver to get optimal channel balance.

 

[PolloLoco]

I previously wrote about a Koss ESP6 mod I'd done - in it's own forum thread. It involved making the Koss ESP6 fully open and rewiring them to run off a Stax pro bias amp.

A short while ago - someone contacted me asking me to do the same with his Koss ESP9. I did it to learn about the differences between the two - and to see if there were tweaks I could do to increase bass on my ESP6. I'm now pretty sure that the ESP9 and 6 drivers are identical, but there's definitely wiring improvements in the ESP9 model I received.

The problem with my Koss ESP6 was that they had next to no bass. I'd removed all damping from the headphones in the process of making them open. The result was fairly fast, micro-detailed headphones - but the extension on both ends was lacking. Treble was not exciting either, cymbals didn't splash properly.

By experimenting with this ESP9 - I realized that having at least 1 piece of the felt on the outside stators (the same felt that came with the headphones) - was absolutely critical to improving the sound. The end result was strong bass and intimate mids, a small soundstage. Before adding the felt - I couldn't hear bass below 50 hz, the drivers would actually rattle. Afterwards, using a tone generator I could hear bass down to 30 hz at my regular listening volume. I may experiment again by adding TWO pieces of felt outboard - the way the headphones were originally damped.

Here are some pics of the project. No part of it was difficult, it's just painstaking work - it takes a lot of time to assemble them correctly. The end result sounds surprisingly great to my ears - I'll be using my ESP6 more often. These are a good complement to the Koss ESP95X which have a bigger soundstage, less bass, but more airy treble. My Stax L700 are definitely better though. The bass is similar, though it's more dominant in the mix with these. The L700 is faster, more detailed - better treble and has a larger soundstage.

 

[GREQ]

100% reversible over-ear mod for vintage Pioneer SE-11 (eleven)

• Carefully remove old pads (and of course store them safely)


• Acquire donor baffles (in this case from cheap faulty headset)


• Begin torture session


• Good enough


• Acquire double sided adhesive 'foam' and HyperX Cloud velour pads


• Apply


• Stick it on

Overall tuning is almost unchanged by this mod.
Comfort is off the charts, as it's already an ultra-light headphone.
These pads might slightly reduce the sub-bass, but it sounds fine. Other pads might perform better.

 

[kopczas]

Hi,
has any of you tried to open or semi-open Yamaha HPH-MT5`s?

 

[kopczas]

At the end, I combined several filters into one “sandwich” filter.

May I ask other materials you used during tuning? I`m creating sandwich filter for Yamaha HPH-MT5.
By far I`ve tried cotton medical pads (full thickness and split in half), some cloth from watch I bought on aliexpress and interfacing.
At this moment sandwich contains full thickness cotton pad and interfacing.
I would not look further but there still too much 4,5-5khz. There is kind of spike which is not pleasant. I`m looking for material to dump HF at this region.

 

[quisxx]

Hi,
has any of you tried to open or semi-open Yamaha HPH-MT5`s?

If you search, you will find modding those was quite popular a while back.

 

[THEYiftah]

Lots of great ideas here.