Philips SHP2500 - The Ultimate Mod
Sep 6, 2015 at 2:09 PM Thread Starter Post #1 of 3


Headphoneus Supremus
Oct 11, 2009
I've owned 6 sets of these over the past year, and have spent many MANY hours modding them.
Firstly because they're one of the best, if not THE best headphone in it's price bracket; so why not take them further?
Secondly because modding is fun!
Most of my historical mods used too many materials, took quite a long time to mod, were slightly costly and were only OK sounding; up until just over a week ago when I came up with the latest mod that made all other attempts seem like utter failures. 
My latest mod crushes all others BY FAR in terms of sound, cost, time to mod, reversibility and ease.
As a foreword: All the sets I've owned were SLIGHTLY different. Some had flabbier bass, some had more strident treble.
Therefore I will not add ANY science to this, since what worked for ONE set of cheap headphones that most likely has a low level of QC, will almost certainly not work for all of them.
So here's what you gotta do.

Step 1:
Get Philips SHP2500 ☺
Step 2:
• Get an empty toilet or kitchen paper roll.
For hygiene reasons, I suggest kitchen roll (roughly 45mm diameter)
• Get cotton wool or similar acoustic dampening material (polyfill, twaron angel hair, synthetic pillow stuffing etc) - you only need 2 tiny pinches of the stuff anyway.
Step 3:
• Remove earpads, unscrew the 3 screws and open those cans up.
Step 4:
• Cut out two 8-9mm deep rings from the roll. Don't worry about cutting along the roll, since 45mm is too large, and you will need to overlap a small area and stick together with tape or glue.
• Cut a small 'smooth' triangle out of one side where the ring will meet the screw-thread-entry which is slightly in the way.
• Simply stick them around the circumference of the driver backs - apply small bits of sticky tape all the way around to make a proper seal.
Step 5:
• Divide the two pinches of cotton wool and spread them out THINLY.
A thick layer of acoustic damping will kill the bass. 
Then you'll have something that looks like this:

Step 6: (optional for bassheads - bass will crush skulls, but you will sacrifice clarity for 'wub-wubz' and bloom)
• As shown above: carefully punch a SINGLE hole in the stock driver vents. (I find that small/medium size screw drivers work quite well for this, just apply pressure and twist - try not to get any debris INSIDE the driver)
◘ This step is reversible if you have Microporous/Micropore tape (medical type, breathable sticky tape) - simply cover the hole with a small piece of this stuff.
Step 7:
• Put it back together and feel good about yourself.
Step 8: (optional)
• Put on some music and enjoy
So the big question is: How Does It Sound?
• First of all, it's important to know how a STOCK SHP2500 sounds like.
Comparing FR to something close to neutral... let's say, a Hifiman HE-500 for example, the stock SHP2500 can be a touch peaky/aggressive in the treble and thins out below 150Hz.
• After modding, treble is tamed very slightly. It still retains sparkle and perhaps aggression depending on the recording. 
• More critically however, the bass extends superbly and is a touch north of neutral.
• Other noteworthy improvements are clearer midrange, improved timbre and a slightly airier sound. 
As a final word, the above mod is not in it's 'final' form - I'm sure there's even more that can be done to squeeze incremental improvements out.
This is however, the simplest, cheapest way to bring these to a much higher class. 
Also my work is a little messy since it was only another 'experiment' that went unbelievably well. 
To add some perspective, I took it to work to get some 2nd opinions (these guys are accustomed to me doing a 'show n' tell' every now and then) - one colleague is considering buying one of these to mod himself, another colleague bought this headphone from me on the same day 

Happy Modding!
Jun 26, 2017 at 11:49 AM Post #2 of 3
Hi Greq

I was looking for a cheap set of headphones for watching movies at night and I was an on a tight budget. what i needed from headphones was to feel comfy for long use, sound good, haveinline volume control, not to leak too much sound out from them.

I went with these (Philips sch2500) and found that they where very comfortable and had great cable length and inline volume but they did leak sound like crazy and need to be turned way up to help get bass as the high's are very very crisp. I tried this mod on them and tried to even insulate the cups but made no difference to them at all. So I went back and got another pair the exact same as I used to have and these where the Panasonic RPHT225 . They are nice to wear and have a ood length lead and inline volume but they sound great and do not leak sound as much as the philips. I used to have these years ago and lasted me for years untll i list them so thats way I went back to them ans they where even cheaper than the philips. what do you thin of the Panasonic RPHT225 as I cant seem to find much on them but they are a great pair of budget headphones I think
Jun 26, 2017 at 1:39 PM Post #3 of 3
These Panasonics were actually one of the first headphones I ever owned, but it was the older model from around 2000.
I thought they were extremely bass light, fairly uncomfortable and way too piercing in the treble. I consider it among of the worst headphones I've ever owned.

My ears and tastes may have changed since then, but I did give the same old set another listen about 5 or 6 years ago, and thought they were pretty terrible then too.
No idea if they updated the design since 2000.

I'm surprised after modification you found there to be no difference at all.
The mod is only designed to change the sound. It has nothing to do with isolation.

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