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Super Panasonic RP-HTX7

post #1 of 9
Thread Starter 

After so much talk about the RP-HTX7 it dawned one day that they might be pretty good outdoor headphones. When modified.

 

So well... The modified set is sitting on the desk next to the MIDI keyboard right now, and it's already played for a few days on the street.

 

Stock RP-HTX7 are very bass-heavy - so much so the bass gets over midrange. Plus they have that Panasonic thin/stiff character which affects the whole sound, bass, midrange, and treble. Recabled, the headphones show some harmonics which were previously dead in the midrange/treble, gain speed and liveliness, and that "Panasonic stiffness" is mostly gone (though the bass is still elastic/punchy rather than "velvety" as in Denon headphones). A problem of the RP-HTX7 is the searing, fatiguing treble. Solved also, with a little fix from the past :-P

 

Summary of the modding...

 

1. Recable to silver-plated twisted pair (AWG 24 main cable, AWG 32 headband).

2. Sunny Bear's mod (two out of three "bass holes" taped over behind the driver).

3. Extra isolation layers (just cotton with some yellow PVC "tablecloth" on top).

4. AKG K-240 cloth over driver grilles.

 

That last mod killed a bit of resolution sharpness, but made them sweeter and calmer, and removed almost all of that fatiguing harshness. So now they're slightly less efficient, but with a much more pleasant sound. Overall, it's a big change, they're not exactly a different set of headphones, but... Yeah, not like the stock set at all. Quicker, livelier, with a real midrange (though still suffering from a slight lack of definition), no boomy bass, soft treble, and a civilised Austrian tint/distance to the sound. More balanced for sure. They won't replace classic silver K-141, but they're very good outdoor headphones. Isolation is where it should be (getting closer to canalphones' when playing). "Super-RP-HTX7". ClieOS compared them to K-81, and well, there're two things that're wrong about K-81... One - they're supra; two - the driver grille tuning is towards low midrange/bass (square holes). RP-HTX7 driver grilles are tuned for high midrange/treble (circular holes). So unless the K-81 had Kramer holes, they'd never get close in sweetness, even though the drivers are good (high-excursion with good midrange dynamics). Both K-81 and RP-HTX7 are punchy, but K-81 are slamming punchy, RP-HTX7 have a more forgiving kind of bass.

 

The isolation is just some cotton glued into the cups with yellow PVC "tablecloth" on top. A secondary effect is reducing cup size, so there's less boominess to the bass. Isolation's pretty good, a construction site with excavators working 10 metres away was muted completely with IPod Touch playing at 90% volume. The cups could be larger - the RP-HTX7 are very small headphones, smaller than they seem to be in photos. They're slightly larger than K-81, DN-HP500, the cups are barely enough to fit ears in. This doesn't leave much room for modding or isolation, but the results are nice. The plastic, of course, is thinner and lower quality than on the likes of AKG K-271 Studio.

 

One pleasant surprise is sensitivity. It's declared at 99 dB/mW, but the AKG K-240 Studio, rated at 96, are way less efficient (by more than 3 dB). So real efficiency must be somewhere around 100-102 dB, and the RP-HTX7 are driven fairly easily. Most players won't have trouble making them shout. The EQ is more towards "loudness", so that helps too.

 

Musically they tend to go well with rock, metal, synth-pop, anything punchy & powerful. But, they also do saxophones and jazz fairly well. Classical music isn't that great in RP-HTX7 unmodded, but modified it's all right. As usual, a recable and general balancing of the sound makes headphones play anything well.

 

Between RP-HTX7 and K-240 Studio, the K-240 are more ambiental, the RP-HTX7 catch some microdetail better and have quicker dynamics. RP-HTX7 have a darker, more closed-in sound with a smaller soundstage, whereas the K-240 are all airy and ambiental with a huge positional soundstage. One last problem is the lack of midrange detail (midrange is not as even as AKG midrange), but the right kind of acoustic foam might fix that (dropping another bit of efficiency, but hey, with a headphone amp that's not an issue).

post #2 of 9

Hello Seidhepriest,

 I just read your 'Super Panasonic RP-HTX7 post and found it very interesting. I have got a pair which have served me well for over a year. It's my entry and only headphone.

Unfortunately, I accidentally pulled the cable while connected to PC source making the jack connector bent. Now, there's little or no sound on the left ear cup. And the ear pads has started to crack and needs replacing.

 I'm not an audiophile and lack the lingo, but I'd like your advice on how to re-cable this phone and where to buy the replacement ear pads. I live in the UK.

Thanking you in advance for advice.

post #3 of 9
Thread Starter 

All right, here's how it looks... They've been modded further, the original left Panasonic capsule broke (wire snapped off the terminal?), so now they've gotten Sennheiser 38-mm. diaphragms off PMX100 (should be the same as PX100?).

 

Click on the images for full-scale photos.

 

Franken-HTX7.jpg

Franken-RP-HTX7-3.jpg

Franken-RP-HTX7-4.jpg

 

All that remains from the original headphones is the structure. Inside the cups there's some acoustic foam, and a layer of cotton padding on the walls, covered with a kind of thin PVC kitchen cloth. The acoustic foam is from old Koss/Radio Shack headphones. The isolation's very effective - the headphones were playing at Starbucks at -10 dB (straight from the notebook) and nothing could be heard except the music. So they are pretty good as "street" closed headphones.


Edited by Seidhepriest - 6/12/11 at 2:48pm
post #4 of 9
Thread Starter 

And now the components.

 

1 set of Panasonic RP-HTX7,

1 set of Sennheiser PMX100.

Gold spiral/black Techflex jacket, which you can get here.

The wires are silver-plated copper twisted pair from Navships, AWG 24 and AWG 32. The headband cable is 4 wires (2 pairs), AWG 32.

The plug is a Neutrik NYS-231B gold/black thing. You can also get NYS-231, it's a bit cheaper - the only difference is it's nickel instead of black/gold.

A bag of cotton.

A thin PVC "kitchen cloth" (they cost pennies, a bag of three was on sale at a local dollar store).

Some glue.

Pocket knife or flat screwdriver.

Cross screwdriver.

Soldering iron, solder, smeltering paste, etc.

Acoustic or packing foam (the porous softer kind, not the thick kind).

 

Cut three equal-length pieces of cable (here it's 1.25 m., same as the original) and mark the left and right pair at both ends. Blue and red paint, or anything really, but the paint has to stay and not peel off as the wires get pushed through the sleeving.

 

Cut a length of sleeving which is slightly shorter than the wires. Braid the three pairs together, push them through the sleeving. Solder the plug first. Then you can solder the wires with a test sound playing. Here it's the left/right channel voice check.

 

From here on, you can either do the easiest fix, which is just soldering the main cable to the left capsule in place of the stock cable, or do the full mod.

 

Take the pads off the cups (they snap off easily), then take the screws out of the cups. Glue the cotton inside the cups (plaster it first, a couple small wads are enough for a cup). Cut a couple cup-shaped pieces out of the kitchen cloth. Stuff the PVC panels on top of the cotton. Put some acoustic foam (plastic foam also works) in the space between the cloth and the capsules.

 

Solder the AWG 24 pairs directly onto the left capsule's terminals. Optionally you can pull the original Panasonic wire out of the headband and replace it with AWG 32 pairs. But this is a bit tricky as to put the new wires in you'd have to cut the threads on the headband and re-sew it (or attach the new cable over the headband somehow).

 

PMX Mod

 

Pry the Panasonic diaphragms out of the enclosure rims. A small pocket knife works for this, the rim may get a bit bent, but nobody will see that.

 

Boil a bowl of water.

 

Take the Sennheiser PMX100 apart. Unscrew the cups off the band. Snip the cups off the wires. Submerge the cups in the bowl of hot water (you don't have to make headphone soup, just pour a bowl of water, don't boil the capsules on fire). Wait for a while until glue softens, then pull the cups apart. Then carefully pry the capsules off the frames with a flat screwdriver or knife. Take them out of both rims.

 

Don't trash the PMX frame - it'll be needed.

 

Now take the PMX cup front halves (the ones opposite the star-pattern lids) and break all the spokes. Make sure no spoke bits are protruding inside the rims. Now flip the capsules so the diaphragms are facing outside the rims. Mark which terminal is positive (they're not marked) with red paint or marker. Insert the diaphragms into the rims so they're facing out of the rims (backwards from how they were in PMX100).

 

Solder two AWG32 pairs onto the PMX terminals. For the right capsule, you can just throw the full headband wire. Cut two lengths of AWG 32 cable that're the same length as the original headband cable. Mark the ends of one of them. Pull the stock cable out of the headband sleeving, and put the new pairs in. Solder the main AWG 24 cable onto the wires thrown from the left and right capsule. Assemble everything.


Edited by Seidhepriest - 6/13/11 at 10:56am
post #5 of 9
Thread Starter 

No idea about replacement pads and whether they're sold by Panasonic at all, but all the parts you can get either off EBay (~2 weeks shipping, and there were some UK sellers) or from a store like Maplin.

 

The Senn PMX100 diaphragms are a lot sweeter and midrangier than Panasonic's original 40 mm. diaphragms. PMX100 cost only $19 here, in the UK they might be cheapie too. The mod is a bit more difficult though, you have to gut PMX100, then tear the spokes off the rims (the diaphragm holders) and insert the diaphragms into the rims flipped backwards, then insert the whole setup into RP-HTX7 diaphragm rims. AWG 24 cables are a bit bulky for direct soldering onto little PMX100 capsule terminals, so they were connected to AWG 32 wires soldered onto PMX100 terminals instead.

 

The sleeving (and plug) can match the headphones' colour. The thick AWG 24 cable that goes to the left cup is three pairs (six wires) - left, right, and common ground.


Edited by Seidhepriest - 6/12/11 at 2:45pm
post #6 of 9

Check this up bro, I make a modding tutorial here:

http://www.head-fi.org/t/638041/rp-htx7-mod-to-the-max

 

Comments and critics are welcomed wink.gif

post #7 of 9
Quote:
Originally Posted by Seidhepriest View Post

No idea about replacement pads and whether they're sold by Panasonic at all, but all the parts you can get either off EBay (~2 weeks shipping, and there were some UK sellers) or from a store like Maplin.

 

The Senn PMX100 diaphragms are a lot sweeter and midrangier than Panasonic's original 40 mm. diaphragms. PMX100 cost only $19 here, in the UK they might be cheapie too. The mod is a bit more difficult though, you have to gut PMX100, then tear the spokes off the rims (the diaphragm holders) and insert the diaphragms into the rims flipped backwards, then insert the whole setup into RP-HTX7 diaphragm rims. AWG 24 cables are a bit bulky for direct soldering onto little PMX100 capsule terminals, so they were connected to AWG 32 wires soldered onto PMX100 terminals instead.

 

The sleeving (and plug) can match the headphones' colour. The thick AWG 24 cable that goes to the left cup is three pairs (six wires) - left, right, and common ground.

 

Seidhepriest, would you be able to re-upload your images? The link seems to be broken and I'm keen to do this mod, but as this will be my first ever mod I think it'd be better to have some pictures to help keep me on track.

Cheers.

post #8 of 9
Thread Starter 

Sometime later, yes... Anyway, the photos only showed the headphones after modding. Nothing internal.

 

Headband wiring was 2*AWG32 twisted pairs, crammed into the original wire sheathing that goes inside the headband. Drivers were eventually replaced by Senn PMX100 drivers as one of the original drivers' soldering terminals broke. PMX100 foam glued over the grilles, too.

 

The mod itself is fairly simple, you take a 3.5 mm. plug, three AWG 24 (better 26) silver-plated copper twisted pairs or similar cable, braid everything together, colour-code the ends of each pair (e. g. blue and red for left/right), solder the plug on, wrap the resulting cable in aluminium foil for shielding, insert it into sleeving. Then connect it inside the left cup, having desoldered the original cable. The right driver is connected via the headband cable, which can be desoldered, pulled out, and then the wiring inside the sheathing replaced with two AWG32 pairs (positive/negative). Don't forget to colour the ends of those too.

 

Other fixes are padding the insides of each cup with plastic fibre and dense cotton for isolation (press it yourself to make it fairly stiff and thin), then lining the driver backs with Blu-tack (insure no holes in the drivers get covered though).

 

Be careful with original Panasonic drivers' terminals, warm up the iron so it melts solder in an instant, poking the iron around for too long can melt the plastic and apparently break some fragile wiring too. That's how one of the original drivers' terminal died.

 

A little bit of warning, the materials for this mod are more expensive than the headphones themselves. The result isn't anything too special, but they work for public transport, especially with the enhanced isolation.

post #9 of 9

I've done some modding too, but rather make it more isolated, I made it into open headphone for indoor/studio use.

 

Mod that I've done:

 

- Recabling using Canare L-2T2S, default RP-HTX7 interconnector, and Canare F-12 Plug

- "Advanced" sunnybear's mod

- Custom  DIY Earpads

- Opening and closing specific holes at cup parts.

 

IMO,  RP HTX7 blessed with good driver.

After doing recabling, I've found that the mid got stronger. Then another founding that reducing distance of driver to your ears will gaining bass and clarity.

In the end It still got bright tone but also got deep bass too!

 

Me too just curious about the modding process and some pic about your RP-HTX7.
PMX is priced about 20$ at my country. I've tried it a long time ago but a bit not sure since these portable headphone are supra aural types.

But in my experience, senn headphone has it's own characteristics: strong mid, calm high, deep bass, and bit muddy.
One thing that I didn't like about senn's low end driver is it's "grainy" sound. But there's possibilities that PMX actually good at circumaural presets....

How about some comparison with some stock headphones?


Edited by Jun Raito - 6/19/13 at 9:38am
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