Dismantling a Pioneer SE-L40 Headphone

I was so lucky to buy a great Pioneer SE-L40 on the Norwegian trading site Finn.no.
These phones have a strong following among headphone addicts and command high prices on Ebay. A nice boxed example might sell for between $125 and $200 US. The main reason for buying a pair is their looks, they may be the most beautiful headset ever made!

There was only one catch with my phones, There was no sound in them, because of this I got mine for $70 including freight. I took the chance of buying a non-player because it´s usually the cable that breaks either at the headphone or at the jack plug, Otherwise there would be clearly visible trauma to the rest of the headset or cable.

I did some searches  to see if there were any dissasembly instructions anywere. The only one I found was at Audiokarma.org. The post showed that the pads  were either glued, or twist locked on.  UPDATE 2015 January: This post http://www.audiokarma.org/forums/showthread.php?t=578603 proves that there are two versions. One is glued on, the other, like mine, is bayonet locked by twisting. The photo below shows the glued version. END OF UPDATE

Photo by sweatyk at audiokarma.com

I was a little apprehensive of using force on the pads, so I decided to study the phones closely with my background as an industrial design engineer. I found the pads are made to twist of using a kind of bayonet lock. In the outer shells inside there are two small semicircular tabs that correspond to flat areas on the earpad base edge. Just twist the earpads until the base lines up and they lift out without any tearing of the fabric.

Screw driver is pointing to flat area on ear pad ring

Screw driver is pointing to tiny semicircular tabs on inside of outer shell

After dismounting the ear pads I removed a metal grill covering a speaker.  They are a loose fit over the speaker. Just lift them of.

The speaker twists out. The two spring loaded brass lugs sit under a shelf molded in the inside of the outer case. There is a hole in the top of the selves, which help you loosen the lugs by pressing them down while you twist and work them out. The plastic holding the lugs on my headphone was brittle, and two of the broke during disasembly. One was regluable with cyanoacrylate, the other crumbled into small parts.

A bit of the cloth covering on the ear pads had come of. I glued it on with a small drop of contact cement.

To keep the headphones apart I used their box and later on, a book. I measured continuity between the speaker elements. No Problems there. Then I measured between the jack plug and the headphones speakers. There was trouble. Now I had close to a 50% chance that the wire break was at the jack plug or the headphones. It is easier to solder in a new jack plug and keep the original cloth covered cable. I took a deep breath and cut of the lower 7 cm of the cable over the jack plug. Peeled back the cloth and measured continuity in the wire. No Luck. The break was either at the head phone side or some were along the wire.  I cut the wires inside the head shell leaving as long wires as possible

There is a small metal clamp that keeps the cable from sliding out. pry it open and keep it for reuse.
Now the cable is free so it can be worked out of the head shell hole.

You will need precision and a very sharp scalpel to cut the cable reasonably well. The cloth is very resilient, and you may end up with a frayed end that is difficult to rethred into the headphone casing.

 

Now its time to cut of the first 5 to 10 cm of the cable, strip it and measure continuity. Success!
I had found the break. It´s late and this is precision work, so I´ll stop for today. Tomorrow I will resolder the wires in the headphone, and mount a new jack plug.

Time for soldering and assembly
I cut 10cm of 4,6mm heat-shink and threaded the cable through. leaving 3cm of wire protruding. As things turned out I would probably leave 4 cm of wire.

Pull the heatshrinked cable through the headphone shell. Clip on the small metal cable-pull preventer, and bend the cable into the groove. This is probably the break point for the cable. The wires should protrude from the cable at the point where they can make the 90 degree bend into the speaker cavity.

solder together new and old wires, or solder directly to the speaker terminals.

Cover with heat shrink.

I use aluminum foil to protect against heat. This also speeds up heat shrinking as the heat is deflected better back at the wire.

Finally the clip is set in its place with epoxy glue since the plastic holding the clip had crumbled from age.

Audio jack plug wiring: Red is right and fit the ring of the plug. (RED-IS-RIGHT-IS-RING) The tip is the left channel and the sleeve is earth.

Picture from http://emailm8.com.au/forms/audio-jack-plug

Listening impressions: My first impression is playing Flac and mp3 files out of the headphone socket on the MacBook Pro, I tried movies, rock, jazz, heavy rock. I used Audio Hijack pro and Blue Cat Audio´s Tripple Eq plug in to explore different equalization of the music. The first thing I experienced was surprise that these phones are written of as bad sounding but great lookers. The sound was full, with plenty of bass, and a rich lower mid tone. I found that they improve by amplifying the high frequencies about 3-5 dB with a 2,5 dB/octave filter centered at 2kHz. Unfiltered they have a prominent lower mid that favors jazz, male voices and bass music but imparts a veiled blurry quality to the music. With extended listening they are comfortable and light. I like the fakt that you can open up the dual headbands so they sit better over your head, but they have rounded pads that feel like the headphones are pushing a bit to the inside of the ear. My daughter felt they tickled her in the ear.