I made a pair of headphones when I was at school, and a rather nicer pair when I was at university. Both were fairly dangerous as I was not aware of the difference between resistance measured using an AVO and resistance measured with 500V applied. Still, apart from one pair catching fire whilst I was listening (saw a little orange glow out of the corner of my eye), there weren't any serious safety issues. They were, of course, electrostatic, and the second pair sounded superb.
I made 4" diameter drivers using clingfilm as the diaphragm, 0.04" polystyrene spacers and perforated stainless steel as the stators. The audio on the stators was nominally insulated from me by 1/2" acoustically transparent foam, and a frame was made out of acrylic. Headband was a rectangle of old jeans with a circular hole cut in it similar to the Jecklin Floats. They were very comfortable. The headphones were connected directly to the anodes of a Quad II valve amplifier.
There are loads of safety issues in building/using electrostatics and it's really difficult to make the diaphragm conductive and keep the spacers from being leaky.
I made 4" diameter drivers using clingfilm as the diaphragm, 0.04" polystyrene spacers and perforated stainless steel as the stators. The audio on the stators was nominally insulated from me by 1/2" acoustically transparent foam, and a frame was made out of acrylic. Headband was a rectangle of old jeans with a circular hole cut in it similar to the Jecklin Floats. They were very comfortable. The headphones were connected directly to the anodes of a Quad II valve amplifier.
There are loads of safety issues in building/using electrostatics and it's really difficult to make the diaphragm conductive and keep the spacers from being leaky.
Thanks for the informative post phidauex. The Hi-Vi 3" is great-sounding (especially with my passive equalization), but now I'm using the Aura 2" and it sounds just as amazing but much lighter!
DIY headphones are indeed tough, but only because speaker drivers tend to be very heavy. But the advantage is low end performace and upper treble (frequency extremes) over commercial headphones that I've heard. Headphones seem to get the mids very well, but compared to my speakers have poor performance in the frequency extremes, like bright treble (Sony SA5000, Grados, Etymotics) which I think comes from nonlinear distortion. I never heard the K1000's, but I've heard most of the other expensive hi-end headphones. The AKG701's that I recently heard sound incredibly good, but low-end performance still not as good as speakers. My goal is to make something that sounds just as good but for far cheaper and better low-end. I'll make some for everyone I know!
I agree that the back chamber is hard to DIY and not very accessible to DIyers, but this only applies to closed headphones. Yeah closed headphones would be really hard to DIY... but open headphones... are easy! I use a 2" inch diameter PVC pipe for the back, sort of like Grado RS1 but slightly longer. Open has more open-sounding midbass (100-300Hz) but less low-end. But with 6mm p-p xmax who cares! It's like a mini-subwoofer!
I need to try that HTRF filter! Then comparisions against speakers would be more fair. My preamp/headphone amp is a Gilmore Dynamic V2, and I think I'll add a circuit for the HTRF filters. Hmmm... but I also think the alternative is also a good option, which is to have some space between the headphones and ears to simulate speakers. Not everyone has an amp with HTRF filters after all.
I'm thinking people can experience great sound for cheap by going for something like:
Source -> 6W Tripath Amp (like AMP3/AMP6/Charlize) -> $20 DIY headphones
And skip the headphone amp altogether in favor of dual-mono speaker drivers. But I think headphone amps can still power them just fine, they just cost too much. My prototypes sound great out of my T-amp (no preamp other than buffer from sound card), except the T-amp has nonexistant bass. But with a modded T-amp it sounded just great. Very neutral and with electrostatic-like "speed" and transparency. Bass is also excellent and the music was very palpable. I'm using the Aura 2" now as the drivers, with passive equalization. Do I think it can compete with the AKG701's? YES! Not in comfort though...
EC8010 - and that's why i'm aiming for dynamic headphones... =)
i've had my fair share of high-voltage explosions...
DIY headphones are indeed tough, but only because speaker drivers tend to be very heavy. But the advantage is low end performace and upper treble (frequency extremes) over commercial headphones that I've heard. Headphones seem to get the mids very well, but compared to my speakers have poor performance in the frequency extremes, like bright treble (Sony SA5000, Grados, Etymotics) which I think comes from nonlinear distortion. I never heard the K1000's, but I've heard most of the other expensive hi-end headphones. The AKG701's that I recently heard sound incredibly good, but low-end performance still not as good as speakers. My goal is to make something that sounds just as good but for far cheaper and better low-end. I'll make some for everyone I know!
I agree that the back chamber is hard to DIY and not very accessible to DIyers, but this only applies to closed headphones. Yeah closed headphones would be really hard to DIY... but open headphones... are easy! I use a 2" inch diameter PVC pipe for the back, sort of like Grado RS1 but slightly longer. Open has more open-sounding midbass (100-300Hz) but less low-end. But with 6mm p-p xmax who cares! It's like a mini-subwoofer!
I need to try that HTRF filter! Then comparisions against speakers would be more fair. My preamp/headphone amp is a Gilmore Dynamic V2, and I think I'll add a circuit for the HTRF filters. Hmmm... but I also think the alternative is also a good option, which is to have some space between the headphones and ears to simulate speakers. Not everyone has an amp with HTRF filters after all.
I'm thinking people can experience great sound for cheap by going for something like:
Source -> 6W Tripath Amp (like AMP3/AMP6/Charlize) -> $20 DIY headphones
And skip the headphone amp altogether in favor of dual-mono speaker drivers. But I think headphone amps can still power them just fine, they just cost too much. My prototypes sound great out of my T-amp (no preamp other than buffer from sound card), except the T-amp has nonexistant bass. But with a modded T-amp it sounded just great. Very neutral and with electrostatic-like "speed" and transparency. Bass is also excellent and the music was very palpable. I'm using the Aura 2" now as the drivers, with passive equalization. Do I think it can compete with the AKG701's? YES! Not in comfort though...
EC8010 - and that's why i'm aiming for dynamic headphones... =)
i've had my fair share of high-voltage explosions...
A lot of headphones respond well to being lifted off your ears by a small amount. I've got a pair of Sony MDR-7506 (a nice closed headphone) that is wearing the earpads from a pair of Beyerdynamic DT250s, which pushes the driver about a half inch farther away from my ear. It helped the sound out quite a bit, as well as adding a more comfortable velour pad, instead of the vinyl pad from before.
Grados are notoriously bright, but I wouldn't say that most headphones are. I've always been impressed with the low end performance of Sennheiser's larger offerings. The HD600 was a long standing champion in solid bass, especially through a serious headphone amp, like the headroom Blockhead. The Orpheus, on the other hand, had pretty unfortunate low end response. But the mids were so delicious I could forgive it.
Basically you are designing and open baffle speaker for near-near-near field use.
You should look over the on-axis response graphs for the speakers you are using, a lot of full range drivers still need a notch filter of some sort. You can probably forget baffle step compensation filters, but you might consider one of the open baffle bass compensation filters, which could affect you, even at ultra-near field positions.
Keep us up with your progress!
peace,
sam
Grados are notoriously bright, but I wouldn't say that most headphones are. I've always been impressed with the low end performance of Sennheiser's larger offerings. The HD600 was a long standing champion in solid bass, especially through a serious headphone amp, like the headroom Blockhead. The Orpheus, on the other hand, had pretty unfortunate low end response. But the mids were so delicious I could forgive it.
Basically you are designing and open baffle speaker for near-near-near field use.
You should look over the on-axis response graphs for the speakers you are using, a lot of full range drivers still need a notch filter of some sort. You can probably forget baffle step compensation filters, but you might consider one of the open baffle bass compensation filters, which could affect you, even at ultra-near field positions.
Keep us up with your progress!
peace,
sam
Regarding Grado headphones and brightness... I suppose brightness is in the ears that listen.
ES headphones are easy and rewarding to build. They require little in the way of special tools or skills to construct. The drivers are easily sized by the builder and will be thin and light. As for safety, this is a valid issue--not just for ES headphones, but for any headphone. Extended listening, even at moderate levels will have a noticeable impact on your hearing in terms of sensitivity, frequency range and tinnitus. The effects of exposure to B-fields or E-fields is not well known, but is a frequent topic of discussion. I have never received an electric shock from an ESL during my 30+ years of owning them. That is not to say that the potential (sic) is not there.
Bottom line is stick with near field monitors if you are worried about the health risks associated with headphones. Otherwise I recommend building a set of ES headphones with a layer of grounded dummy stators and 20 MOhm series resistance in the polarizing supply for (electrical) safety.
...j
As an aside... I wonder how many lawsuits have been filed over the years against Quad, Acoustat, Martin-Logan, Audiostatic, KLH, Dayton-Wright, Koss, Janzen, Infinity, Stax, Jecklin-Float, Beveridge, etc. for consumer liability issues related to electrostsic transducers? Not many I guess as these boutique companies could not survive multiple litigations, I suppose.
ES headphones are easy and rewarding to build. They require little in the way of special tools or skills to construct. The drivers are easily sized by the builder and will be thin and light. As for safety, this is a valid issue--not just for ES headphones, but for any headphone. Extended listening, even at moderate levels will have a noticeable impact on your hearing in terms of sensitivity, frequency range and tinnitus. The effects of exposure to B-fields or E-fields is not well known, but is a frequent topic of discussion. I have never received an electric shock from an ESL during my 30+ years of owning them. That is not to say that the potential (sic) is not there.
Bottom line is stick with near field monitors if you are worried about the health risks associated with headphones. Otherwise I recommend building a set of ES headphones with a layer of grounded dummy stators and 20 MOhm series resistance in the polarizing supply for (electrical) safety.
...j
As an aside... I wonder how many lawsuits have been filed over the years against Quad, Acoustat, Martin-Logan, Audiostatic, KLH, Dayton-Wright, Koss, Janzen, Infinity, Stax, Jecklin-Float, Beveridge, etc. for consumer liability issues related to electrostsic transducers? Not many I guess as these boutique companies could not survive multiple litigations, I suppose.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.