The Different impedance taps allow a user to get the most wattage possible in a given situation. A 16 ohm speaker into the 16 ohm taps on my amp will get you 50 watts. A 16 ohm speaker into the 4 ohm taps will get you better amplifier performance, but with way less wattage. A 4 ohm speaker into the 4 ohm taps will get you 50 watts, but a 4 ohm speaker into 16 ohm taps will get you pure unadulterated crap..If your lucky.. So, in my case, 50 purely resistive ohms into the 4 ohm taps should get a relatively tiny amount of wattage, but excellent performance, and by the sound of the Neo 3's, I am..
Here is an example. Not my amp, but somewhat similar in that it is an ultralinear. Look at figures 6 through 8..
http://www.stereophile.com/content/primaluna-dialogue-seven-power-amplifier-measurements
Here is an example. Not my amp, but somewhat similar in that it is an ultralinear. Look at figures 6 through 8..
http://www.stereophile.com/content/primaluna-dialogue-seven-power-amplifier-measurements
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I can't wait to see where this goes. Are you able to measure the in-ear response? I've had great success with Panasonic capsules when it comes to tuning my Fostex T50rps. If you can get the FR flat to a bit above 1 kHz you can start manipulating the high frequencies on the ear side with various fabrics etc.
I am going to tape off the vents, and file down the corners. The vinyl will probably rip if I don't. I am going to go naked with the phones, mainly to keep the weight as low as possible. I ordered 4 tiny rectangular aluminum bars that are 2" x 1/2" x 1/4". They will be attached with superglue to each side of the Neo's right next to the vents where it is flat. Holes will centered in the middle of each bar's 1/2" width to connect to the yoke. As far as the headband goes, It is very narrow, but also very flexible. No pressure when I wore them..
I will probably send them to Tyll Herstens of Innerfidelity for testing. He has a $20,000 dummy head with all the gear.
Resources | InnerFidelity
Where can I get those capsules? It would be nice to do some preliminary testing before I embarrass myself..
I bought mine from ebay for about $2 each. Panasonic WM61a. They are very flat up to about 10 kHz, which is about where the positioning error becomes significant anyway.
You can get great results from these without a preamp, even. Headphones are easier to measure than speakers because you have the mic so close and you very easily get a good SNR. Tyll's setup has a lot going for it. But the limited factor is the same in both cases - placing the headphones on the head consistently.
Here's an example of my AD700s measured in ear using REW without any preamp in the chain and without bothering to average out measurements/deal with ambient noise.
You don't need better precision than this, in my opinion. Besides, you want to know how it behaves on your head, not the dummy head.
I'm symphonic over at HeadFi, btw. I'd be happy to help you get setup, esp. if you're in Europe.
You can get great results from these without a preamp, even. Headphones are easier to measure than speakers because you have the mic so close and you very easily get a good SNR. Tyll's setup has a lot going for it. But the limited factor is the same in both cases - placing the headphones on the head consistently.
Here's an example of my AD700s measured in ear using REW without any preamp in the chain and without bothering to average out measurements/deal with ambient noise.
An externally hosted image should be here but it was not working when we last tested it.
You don't need better precision than this, in my opinion. Besides, you want to know how it behaves on your head, not the dummy head.
I'm symphonic over at HeadFi, btw. I'd be happy to help you get setup, esp. if you're in Europe.
I agree with your "accuracy" statement. Once you attain a certain tolerance, It becomes a purely subjective experience. I do think that square wave and hd perfomance is very important though.
I have to include that my only experience with high end phones is with Ety er4p's( Also Grado SR125's). A drastically different subjective experience than with over the ear, open backed phones.
One of the things I have noticed is that the air volume between the cups and your head has a profound effect on the the tuning of the planar magnetic diaphragm. A large air mass makes the diaphragm too loose and resonant and a smaller air mass makes it too tight and restricted, like it would in an acoustic suspension speaker, but in this case, your head is inside of the "speaker cabinet" instead of on the outside.. This is starting to get complicated...
One of the things I have noticed is that the air volume between the cups and your head has a profound effect on the the tuning of the planar magnetic diaphragm. A large air mass makes the diaphragm too loose and resonant and a smaller air mass makes it too tight and restricted, like it would in an acoustic suspension speaker, but in this case, your head is inside of the "speaker cabinet" instead of on the outside.. This is starting to get complicated...
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Here are the Innerfidelity measurements of the AD700s. Interesting comparison..
http://www.innerfidelity.com/images/AudioTechnicaATHAD700.pdf
Here are the Innerfidelity measurements of the AD700s. Interesting comparison..
http://www.innerfidelity.com/images/AudioTechnicaATHAD700.pdf
Open style headphones can be VERY sensitive to placement on the head and proximity to the ears.
I heard these Sony MDR-F1 years ago and wanted to like them, but tonality and bass response was very touchy depending on the fit to your head. Too bad, because they were very light and comfortable on the head. No pressure at all.
Greg
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Greg
I think that there is something else going on here. I'm not sure, but I think that the the qualities that make electrostatic and planar magnetic headphones so appealing, are also the qualities that make them very sensitive to factors that conventional drive units are way more immune to. Somewhat analogous to a Ferrari compared to a Lexus..
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By no means am I comparing this BG Neo headphone experiment to a Ferrari (HA!). But it is very temperamental and needs a lot more fine tuning to be optimized. It's not just a matter of sealing one side to your head and having the other side open. I'm finding that it is much more delicate a process than that..
After screwing around with a lot of different things to try to get the frequencies above 700hz more pronounced and elevated, I have decided to end this experiment on the grounds that the the Neo 3s I own are the wrong ones for the job. The "progressive drive radiation technology" that makes this particular driver so good for tweeter use, seems to be the one thing holding it back for use as a headphone transducer. It's kind of ironic that this tweeter, measured as a full range dipole on a baffle at 1m, starts rolling off the "lows" below 700 hz. Using it close up to the ears with semi airtight headphone cushions attached, it does exactly the opposite. It starts rolling off the highs above 700hz. When I initially measured them with my crude arrangement, I thought the above 700hz rolloff was just an artifact of that crude measurement(Turned out that it wasn't) I think the non PDR Neo 3s would not have done this because there are no fibers damping or covering any part of the diaphragm. Oh well, maybe someone else with regular Neo 3s can take the ball and run with it...
Seth
Seth
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RE: the AD700s measurements on my head vs Tyll's - there is an important difference that I'm using blocked ear canal measurements so don't see the same gain around 2-4 KHz range. I could actually use the difference between the curves as a calibration to see how headphones he has measured would look in my setup, assuming linearity.
Before you give up completely, can you try them in a closed back config? Fostex T50rps have a very decided step down around the same 800-1000 Hz range when they are totally open backed. I have a curve on my home PC that I can post later.
You will be able to reduce the lows by choking the driver at back.
The LCD-2 step at 1 kHz would probably be worse with less damping.
Before you give up completely, can you try them in a closed back config? Fostex T50rps have a very decided step down around the same 800-1000 Hz range when they are totally open backed. I have a curve on my home PC that I can post later.
You will be able to reduce the lows by choking the driver at back.
The LCD-2 step at 1 kHz would probably be worse with less damping.
Thanks a lot for the help, I'll try it.
As an aside to all of this, When I ordered the Monoprice full sized sealed back phones(for the Neo 3 experiment) I also decided to try their in ear phones to compare with my er4p's. They were under $10.00 so it wasn't a risky purchase. After comparing them, I would have to say that they are an unbelievable bargain! They are shockingly good! The "enhanced bass" is extended but not bloated. The mids and highs are a touch grainy compared to the ER4P's but at 1/25th the cost, who cares?
http://www.monoprice.com/products/p...=10823&cs_id=1082303&p_id=8320&seq=1&format=2
Seth
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Here's the example of the T50rps with the back of the cup open - this big 10 dB drop off can be removed by damping. You can actually get the thing flat up to about 10 kHz but that wouldn't be a good match for HRTFs. Hopefully some stuffing can do the same for your tweeters.
Interesting RE: the Monoprice IEMs. I have a friend going to the US in June, I'll probably ask him to bring back some Monoprice cables. Maybe I'll throw in a couple of these.
Interesting RE: the Monoprice IEMs. I have a friend going to the US in June, I'll probably ask him to bring back some Monoprice cables. Maybe I'll throw in a couple of these.
An externally hosted image should be here but it was not working when we last tested it.
That curve looks almost identical to the neo 3 measurements I made. This gives me hope! Like you said though, "flat" is still not even close to the ideal HRTF curve, but at least it would be somewhat enjoyable to listen to. The HRTF curve is about 10 db up at 2khz which sounds "flat" to our ears. So a flat response is going to sound like a 10db dip to our ears. That is a huge difference. The uncupped fostex is going to sound like a 20 db dip at 2khz. That's what I'm hearing in the Neo 3s current state. Ouch!
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