Dreadhead

Middle of February?

I should add the differences are at such low amplitudes I can't say they are trustworthy though they are repeatable.

Nope. It's a block of modeling foam with an omnidirectional measurement mic shoved through it. I would love to get a true binaural head but I've not got the money and to be honest it would be of limited use to me. In the end whatever problems this would have should show in all the measurements so the comparison is still valid. Oh and all measurements are the average of 4 sweeps.

Unfortunately not doing this with an AP system so don't have those curves. I do have the impulse responses and I'm plotting those as we speak: The first attached is the Impulse response for all 3 versions where the phones are being driven SE. The last if for all 4 and you can see that the response is slightly different for the Balanced line (the line that's been added).

Here are the THD results for a 997.6 signal for cases 1,2,3 in that order. the two SE cases it's 0.347% and for case 1 it's .351%

Well I just got done doing tests on the HD650 using my ECM8000 measurement mic and dummy head and room EQ Wizard (that some of you have seen). I kept the mic and headphones in the same spot and tried the following: HD 650 running Balanced from the GS-X (of DAC3 Balanced) HD 650 running SE from the GS-X (of DAC3 Balanced) HD 650 running SE from AE-2 plugged in with wall wart(off DAC3 SE) HD 650 running SE from AE-2 running off battery (off DAC3 SE) I attempted to volume match all 4 configurations but ended up having about .3 db (at 1kHz) variation that I could take out using the software so they all have the same value at 1kHz. Attached are the frequency response curves for the four configurations. The second one has a vertical separation introduced so you can see that there are different curves. Amazingly Identical. The most difference I can find is on the order of less than 1db.

cute kid Cool amp

:D:D:D:D Did you do it right? If so you may not be able to be included.

Well over the weekend I tried to turn the SA500s into the HD650s and the results were less than impressive: There were odd distortions and resonances going on. It turns out that at least for the SA5000 the distortion products are large at some frequencies and hence have a large effect on the sound. At 6710Hz I measured 20% distortion (though this is where there is a huge dip in response). I always said that this method needed a well behaved source to work and it appears the SA5000s are not it. On the other hand with the 650s as the base the method works great and you get the SA5000 sound beautifully and you get flat sound after the correction as well. I am pleased with the progress. I rewrote everything to work in Octave now so it's all on one machine.

Actually a lot of the peaks and lulls caused by cavity resonances are linear on the base frequency and can be captured. That said the wavelengths of audio sound waves in air are huge compared to the cavity of headphones. This is actually why they use convolutions to model reflections from walls. The harmonic distortion products as I said before I can't do anything about but 70 db is a fair amount of headroom. That said if you listen really hard for that signal it won't be there. Of course everything I've said is impossible.

Oh I know but I'm just showing that the only distortion I would be introducing is the noise in the signal and the distortion of whatever the target being modeled may be. As someone else pointed out (quite rightly) the convolution process is purely linear so harmonic distortion is not going to happen so all I can see is the noise problems and the distortion of the actual target and transducer.

Well I just checked the math some more and It works out that if I write the files at 24bit my noise floor stays below -130db. So much for "introducing shitty distortion"

So has anyone tried it? Thing that amazes me is how well all phase information is still preserved (not that it shouldn't be). This weekend I'll see if I can turn the 650s into d5000s, the 5000s into 650s and something into the ESP950s By I'll see I mean I'll see if I have time. In other news it looks like I'll be switching back to foobar2000 since they finally fixed the issue with Hi Rez WMA

He can afford anything his heart desires? How about giving your crap away for free then....

Actually on head-case I can be condescending if I want to especially if it was a joke. People take boards way to seriously, even here. I don't own this thread it's a free for all as you and I both know. If I wanted that bull crap I would have posted over at HF and you don't need to explain the rules to me (in a rather condescending manner I might add).

You're welcome.

Well here is the IRF I have for turning HD650s into SA5000s, Download the convolver pluging for Foobar and use this and you will see: foobar2000: Download foobar2000 and optional components Enjoy one and all. Convert.zip

Lets not get into that people. Yes there is distortion and yes it's very small....

You mean you don't? You poor Luddite

hmm well I will think about that, I had not thought about it that way but I can see where you're coming from. Luckily I'm into SS so I can't care about tube harmonic distortion As far as turning the phones from one to another it appears to work though.

May I ask why not?

It works muhahahahahah I am listening to HD650s that sound exactly like SA5000s. This is so freaking cool.

1) Room EQ calculates both and keeps track of phase. Rest assured it gives the IRF. 2) yes it has a convolver and it takes a wav file. If I get the mics I can use it for the HRTFs as well. I have sorted out the math and have the inverse of the IRF etc working. Good times. I will see what I end up with later. Distortion should end up as both phase and amplitude response and hence I should capture it but we shall see. The guy who built the convolver has stuff to model tubes etc on his website.

hmmm Octave looks good. I will likely use that instead since I would have to use the the Matlab from work and I would rather not.

Actually out of pure laziness I will use Room EQ Wizard to get the IRFs and then do the math in Matlab since I have all my code already written in matlab and it has a WAV reading algorithm already. I'll then use the convolver plugin already built for foobar. As far as lesser and greater headphones I've measured R10s and their frequency response is crap but they sound lovely. I don't know what their phase response is. Btw I hate mathematica, I use maple for symbolics (not that I do that much these days, mostly pencil and paper)