Capt'n Corrupt | # 21 | 2007-12-02, 20:42 | Report

This would be AMAZING. I'm very eager to find out what can be done with the N810. Keep us posted!

I wish I had information to contribute, but alas, I'm N810-less...


}:^)~
YARR!

Capt'n Corrupt

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Last edited by Capt'n Corrupt; 2007-12-02 at 20:46.

Capt'n Corrupt | # 22 | 2007-12-02, 21:24 | Report

For those interested in wireless streaming from a computer check this out:

http://labs.morpheuz.eng.br/blog/24/...g-with-netcat/

It would just as easily work in reverse, to digitally (and wirelessly) stream audio/video to a media server.

It needs a nice interface, though. Hopefully Canola can handle this!


}:^)~
YARR!

Capt'n Corrupt

ArnimS | # 23 | 2007-12-03, 11:57 | Report

Beat frequencies are generated by two overlaid waves at different frequencies. If for e.g. you play back a 400hz wave and a 406hz wave, your ear will hear a wave at 6 hz.

For the ear to hear a beat frequency does not require a playback mechanism capable of reproducing a carrier at that frequency. Specifically, to hear a 6hz (cycles per second) frequency using ~400hz carrier waves, any speaker or headphone will suffice. Here, i show yuu.

http://pupnik.de/beat_frequency_6hz_at_400hz.mp3

dsmudger | # 24 | 2007-12-03, 12:34 | Report

Sure - just someone who knows what they're doing let me know what to do, e.g. "buy this cable from here (or better buy one for me ), run this command/post this log file output" etc and I'll be happy to oblige


Incidentally - the low-end in-ear earphones by Sennheiser (about £30-40 high street price, the ones with the black rubber domes) are a great match for the N810.

If you haven't already replaced the total-waste-of-time Nokia freebies, I'd recommends these as the ones to go for as to my taste, this combo sounds great at all volumes with no need for any EQ (which is good because none is available in any of the maemo media players AFAIK?)

(fair enough, including throwaway headphones increases the manufacture cost by only a few cents, so you might as well, but why-oh-why didn't they make them interchangeable at the mic/remote?? what a waste... )

Just like the 770 though, plug in something a bit more serious like a Shure e5c and the sound all goes into the midrange with harsh/overly bright treble - much like a clock-radio kind of speaker - but the Senn's fat/quite uncontrolled bass-iness offsets the tight-but-light bass of the N810, and kind of reigns in the harsh treble - end result is very nicely balanced sound IMO, especially for the price (better than the same phones driven by for example iTunes+iMac internal sound card, which sounds excessively boom-y to me).

Been listening to a lot of last.fm in Vagalume at work with this setup - very happy with it this way - and so much easier to untangle myself (than something like the e5c) when someone comes over with a question or something

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Last edited by dsmudger; 2007-12-03 at 12:41.

Capt'n Corrupt | # 25 | 2007-12-03, 13:37 | Report

The insight is much appreciated! However, it is the carrier frequencies are in question. With certain binaurals, the carriers themselves can drop to the sub 10Hz level (6Hz with beats at ~0.2, I've read). I would imagine that regular headphones would butcher sound at this level especially given the standard amplifiers in most (not excluding the N810) portable listening devices. Though the beat frequencies are likely inaudible, there is apparently a very real psychological effect that the recordings have. I would imagine, that at this ultra-low level, its likely that special binaural headphones would have to be purchased.

For the time being, though, it doesn't hurt to have a good pair of headphones to take advantage of a wider and more consistent frequency spectrum for normal listening! The ability to use the N810 for this task further broadens its usefulness.


}:^)~
YARR!

Capt'n Corrupt

Capt'n Corrupt | # 26 | 2007-12-03, 13:47 | Report

I wish I could help, but I don't know enough, and would hate for you to waste money on equipment for something that may work.

Does anyone have any ideas/experience that could lend a hand?


Good recommend! I'll look into this, as I'd like a nice (almost dispensable) pair of headphones to take with me on the road when I'm walking about. I could stand to lose ~$60 headphones, but losing/damaging $200+ would be devastating. Additionally, carrying an additional 4"x3" amp to take advantage of the headphones whilst out and about, is less than appealing.

I'll take a closer look at the 'casual' Sennheiser headphones! Thanks!


}:^)~
YARR!

Capt'n Corrupt

Mara | # 27 | 2007-12-03, 13:56 | Report

I just ordered myself Shure e2c in-ear headphones. Those go now around $60-70 in the US... and should be relatively decent in sound quality. (And do block background noise quite effectively.)

I'll post back about my experience once I receive them.

Mara | # 28 | 2007-12-04, 00:11 | Report

Just got them today. Overall I'm very pleased with them.

Sound quality is very good. (That shouldn't be a surprise... since we are talking Shure... ) The volume, while can not be adjusted to insane levels, is loud enough, especially when you know that background noise is almost completely sealed outside.

Some reviews I read some people said that these may not be comfortable to wear for everybody. I didn't wear them very long yet, but initially they do not feel bad at all. Much better than my other cheap earplugs I bought few months back...

So, if you are thinking about spending about $50-$100 range in headphones you should not forget to try these...

speculatrix | # 29 | 2007-12-05, 00:00 | Report

one issue with really low frequencies will be how the output from the A-D converters is coupled - chances are it's capacitively coupled and will thus effectively be a high-pass filter.

Benson | # 30 | 2007-12-05, 01:11 | Report

Well, as an EE, or at least a recent EE graduate, I think it's something I can really do well at home.
I have a couple scopes, signal generator, counter, and the like sitting around, and know how to use them.

Output some pure sine waves at various frequencies from the N800, into some appropriate load, and measure the voltage across the load. 20 log10(v/v0) is your friend!

That comment from speculatrix is dead on, of course. The low frequency reproduction of a DAC is perfect. But it is no doubt capacitively coupled, so it will roll off (probably 20dB/dec, not that it matters) at low frequency. I can hook up, say, the comes-with phones, and take some measurements to find the corner frequency.

Regarding the comes-with phones. They killed my ears! Until I took the rubber rings off. Now they fit OK, though the sound is still poor. But having the mic on there means I get to keep them for VoIP, and I'm not going to swap headphones all day. (Does that switch do anything, anyway?) I think, when I have too much time, I shall hack in a 1/8 jack in the mic unit, allowing me to use my Rio earbuds.