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PhilNYC
2005-10-27, 10:14
Sorry if this question has already been asked, but I'm sure there are a lot of folks here that would like to know. Sean, do you consider yourself an audiophile? And if so, what kind of gear do you run at home?

sleepysurf
2005-10-27, 10:33
GREAT question! And, perhaps more importantly, are *any* of the actual Slimserver software development team "audiophiles"? If not, we need to arrange demos for them!

pfarrell
2005-10-27, 10:40
PhilNYC said:
> Sorry if this question has already been asked, but I'm sure there are a
> lot of folks here that would like to know. Sean, do you consider
> yourself an audiophile? And if so, what kind of gear do you run at
> home?

I'm not Sean, but he is an engineer. Most of the engineers that I know,
and many like music and put big bucks into audio gear, don't like the term
"audiophile" because some of the stuff out there being flacked, like ink
to color the edges of a CD, or $100 blocks of wood to hold your speaker
wire in alignment, tend to cause engineers to skoff.

And don't all real audiophiles wax endlessly about how vinyl is better?


Pat
http://www.pfarrell.com

seanadams
2005-10-27, 10:47
Sorry if this question has already been asked, but I'm sure there are a lot of folks here that would like to know. Sean, do you consider yourself an audiophile?

Absolutely!


And if so, what kind of gear do you run at home?

Mostly I listen in my bed room to a wall-mounted B&O 9000 with SB2 on the AUX input, an Adcom amp on the line outs, and a set of Energy floor standing speakers. The speakers are pretty and match my furniture, but they sound horrible (muddy one-note bass), so they're going soon - problem is I can't find a good full-range speaker that will fit in the space I need them to, so I may end up building my own sealed sub box to go somewhere else in the room, and putting Vienna Acoustics up on the wall. Next on the list is to swap out the Adcom for a McIntosh and set the SB3 right on top of it.

In the living room I have big Infinity studio monitors which have incredibly good bass, running off a Rotel receiver for the A/V system.

In the past I've been really into car audio - fun stuff because in such a small space there's really a lot that you have to tweak to get it right. Active crossovers, passive crossovers, sub enclosure geometry, tweeter angles... tiny tweaks make a huge difference in the car.

kjg
2005-10-27, 11:20
$100 blocks of wood? No self respecting audiophile would use something
so cheap ;-)

Pat Farrell wrote:

>PhilNYC said:
>
>
>>Sorry if this question has already been asked, but I'm sure there are a
>>lot of folks here that would like to know. Sean, do you consider
>>yourself an audiophile? And if so, what kind of gear do you run at
>>home?
>>
>>
>
>I'm not Sean, but he is an engineer. Most of the engineers that I know,
>and many like music and put big bucks into audio gear, don't like the term
>"audiophile" because some of the stuff out there being flacked, like ink
>to color the edges of a CD, or $100 blocks of wood to hold your speaker
>wire in alignment, tend to cause engineers to skoff.
>
>And don't all real audiophiles wax endlessly about how vinyl is better?
>
>
>Pat
>http://www.pfarrell.com
>
>

PhilNYC
2005-10-27, 12:00
$100 blocks of wood? No self respecting audiophile would use something
so cheap ;-)

Darn, you beat me to it... ;-)

Sean, nice to hear that you are afflicted just like the rest of us. However, I noticed that you didn't discuss the cables and power conditioning used, so at the moment, you only qualify as a "newbie audiophile"... ;-)

seanadams
2005-10-27, 12:50
Darn, you beat me to it... ;-)

Sean, nice to hear that you are afflicted just like the rest of us. However, I noticed that you didn't discuss the cables and power conditioning used, so at the moment, you only qualify as a "newbie audiophile"... ;-)

I'm using 12 AWG romex for the speakers, CAT5 for the RCA cables, and twinax for the AC power. Can I get my membership card now?

seanadams
2005-10-27, 12:51
I'm using 12 AWG romex for the speakers, CAT5 for the RCA cables, and twinax for the AC power. Can I get my membership card now?

( kidding )

CardinalFang
2005-10-27, 14:43
( kidding )

Ah - it was a test to see if the true audiophile would spot that you had failed to mention the direction of the cable and its orientation with repect to magnetic North.

Does anyone remember the HiFi show in the UK where Linn removed all the telephones to stop the handset speakers vibrating in response to the other HiFi speakers and so muddying the sound? I do.

No, I'm not kidding.

I gave up on the more lunatic fringes of HiFi when I realised that (a) most of the practitioners never went to live concerts and (b) they were past their 20's so their hearing was on its way down the slippery slope to ear trumpets anyway!

Now if you'll excuse me, I have to refill the treacle dampers on the tonearm on my totally non-resonant and non-magnetic entirely made of styrofoam turntable and pass the ultra rare caesium/cobalt magnets over my speaker leads to re-align all the electrons. If I don't do that, they will all all over the place and quantum effects will distort the cymbals on my Ramones CD.

Hello nurse - time for my medication already?

Paul

dwc
2005-10-27, 20:34
And have you placed "feet" under your speaker cable such that the cables do not come into contact with the floor?

-Dan

(whose speaker cable is made out of 14g computer power cords with the ends cut off)

pfarrell
2005-10-27, 20:44
On Thu, 2005-10-27 at 20:34 -0700, dwc wrote:
> (whose speaker cable is made out of 14g computer power cords with the
> ends cut off)

Last time I checked, 14 gauge wire was good for like 15 amps.
How loud do you listen? and how many watts of power does your amp put
out?

--
Pat
http://www.pfarrell.com/music/slimserver/slimsoftware.html

jhwilliams
2005-10-27, 21:24
Last time I checked, 14 gauge wire was good for like 15 amps.
How loud do you listen? and how many watts of power does your amp put
out?


A mere 1800 watts!

Of course, 14 gauge is important for resistance characteristics, esp with long runs... Also there is skin effect, bright colouring and branding to consider!

CardinalFang
2005-10-28, 01:28
Also there is skin effect

I used to develop software for a crack inspection system that used the skin effect. In essence, the higher frequencies travel close to the surface of the metal, so if there is a crack they have to go a further distance (down one side and back up the other of the crack). It was very reliable and just goes to show that the higher freqencies in a signal can travel further than the lower ones if the cables have cracks in the surface...now of course whether it has audable affects is a different matter.

Paul

seanadams
2005-10-28, 19:28
on a bit of a tangent here... (not a joke)

There is another kind of "skin effect" which supposes that the geometry of the face and ears play a huge role in how we resolve the source of a sound in space. Specifically, components above a couple KHz like to stick to the surface of your head, resulting in low frequencies hitting the ears mostly directly, but with increasing frequency there is a very complex mix of phase shift and reflections created by the outside of your noggin that the brain needs in order create the sense that we call "soundstage". The intricacy of the outer ear suggests there's a whole lot of "mechanical" processing going on there, way beyond just scooping the waves into the ear canal. This is why headphones, althgouh they can have extremely _clear_ sound, are not real good at putting the sounds all around you in space.

Some guys are working to model this phenomenon and create filters for headphones that go way beyond simply mixing in a little sound from the other channel:

http://www.headphone.com/products/faqs/about-headroom-crossfeed/fixing-headphones-with-electronics/

Robin Bowes
2005-10-29, 14:14
seanadams said the following on 29/10/2005 03:28:
> on a bit of a tangent here... (not a joke)
>
> There is another kind of "skin effect" which supposes that the geometry
> of the face and ears play a huge role in how we resolve the source of a
> sound in space. Specifically, components above a couple KHz like to
> stick to the surface of your head, resulting in low frequencies hitting
> the ears mostly directly, but with increasing frequency there is a very
> complex mix of phase shift and reflections created by the outside of
> your noggin that the brain needs in order create the sense that we call
> "soundstage". Just looking at the funny shape of the outer ear indicates
> there's a whole lot of "mechanical" processing going on there. This is
> why headphones, althgouh they can have extremely _clear_ sound, are not
> real good at putting the sounds all around you in space.
>
> Some guys are working to model this phenomenon and create filters for
> headphones that go way beyond simply mixing in a little sound from the
> other channel:
>
> http://www.headphone.com/products/faqs/about-headroom-crossfeed/fixing-headphones-with-electronics/

This technology is basically artifically emulating the HRTF
(Head-Related Transfer function).

If you have access to the appropriate equipment (anechoic chamber,
in-ear measurement mics, analyser, sound sources, etc.) you can have
your own HRTF measured and, in theory (maybe even in practise) create a
filter with the same response which can be applied to music that is
being listened to through headphones to add the spatial content.

slimserver could support this by having the capability of applying any
arbitrary digital filter function to its output.

Of course, you'd still need to get your HRTF measured!

R.
--
http://robinbowes.com

If a man speaks in a forest,
and his wife's not there,
is he still wrong?

CardinalFang
2005-10-30, 01:34
This technology is basically artifically emulating the HRTF (Head-Related Transfer function)

I've tried this kind of technology out for game development as it's pretty good for special effects, well good enough for "there's a car coming up behind" or "there's a bad guy breathing in the shadows to your left". It alters sounds to place them, so I'm not too keen on it for music that was originally mixed for 2 channels. If the sound was recorded for this purpose, then that's different.

The BBC did do some plays on the radio for headphones using similar technology and it was very effective - very atmospheric and great placement of charecters in a scene, but it was fairly simple sound staging.

Paul

Mike Anderson
2005-10-30, 08:32
So my friend comes over an' says "Your stereo sounds like crap" an' I say "Maybe its 'cause your protudin' nose is diffusin' the hi frequencies, the mids are bouncin' off your bald head and the bass is gettin' lost in your double chins" so he punches me in the face and flattens my nose.

Now it sounds even better.

dwc
2005-10-30, 21:36
Tyll Hertsens of Headroom touches on "skin effect" and other related concepts in a nice posting on crossfeed:

link to post at head-fi (http://www6.head-fi.org/forums/showpost.php?p=1675900&postcount=30)

-Dan

Robin Bowes
2005-10-31, 00:13
dwc said the following on 31/10/2005 04:36:
> Tyll Hertsens of Headroom touches on "skin effect" and other related
> concepts in a nice posting on crossfeed:
>
> 'link to post at head-fi'
> (http://www6.head-fi.org/forums/showpost.php?p=1675900&postcount=30)

Actually, thinking about this a little further, if we could get hold of
pretty much *anyone's* HRTF it would be possible to apply it digitally
to the signal before streaming it to the SB. Or it might even be
possible to do it in firmware? Dean?

R.
--
http://robinbowes.com

If a man speaks in a forest,
and his wife's not there,
is he still wrong?

Fifer
2005-10-31, 01:19
So my friend comes over an' says "Your stereo sounds like crap" an' I say "Maybe its 'cause your protudin' nose is diffusin' the hi frequencies, the mids are bouncin' off your bald head and the bass is gettin' lost in your double chins" so he punches me in the face and flattens my nose.

Some guys are working to model this phenomenon and create filters for headphones that go way beyond simply mixing in a little sound from the other channel:
I wonder if such a filter could be switched between 'pretty' and 'ugly' settings?

dean
2005-10-31, 13:02
On Oct 30, 2005, at 11:13 PM, Robin Bowes wrote:

> dwc said the following on 31/10/2005 04:36:
>
>> Tyll Hertsens of Headroom touches on "skin effect" and other related
>> concepts in a nice posting on crossfeed:
>> 'link to post at head-fi'
>> (http://www6.head-fi.org/forums/showpost.php?p=1675900&postcount=30)
>>
>
> Actually, thinking about this a little further, if we could get
> hold of pretty much *anyone's* HRTF it would be possible to apply
> it digitally to the signal before streaming it to the SB. Or it
> might even be possible to do it in firmware? Dean?
I'd assume that the calculated filter would have a fairly large
number of coefficients and while the CPU in SB2/3 is fast, it
probably wouldn't be able to handle that much additional DSP. Better
to do it in the server.

CardinalFang
2005-10-31, 14:22
I'd assume that the calculated filter would have a fairly large
number of coefficients and while the CPU in SB2/3 is fast, it
probably wouldn't be able to handle that much additional DSP. Better
to do it in the server.

I've seen it done on a cellphone (ARM9, 100Mhz), since most of the work is done upfront processing the audio before transmission. It's the same old story, you can take your time pre-processing the signal so that it's quick to decode. If I remember correctly, it was under 10MIPS to decode a spatialised stereo signal, no filtering like reverb or doppler though. I don't know the DSP on the SB that well, does it do floating point calculations, or is it all integer maths?

Whether there is enough spare processor bandwidth is another question, as is whether it's a useful feature or a novelty. My gut feeling is that it's the latter, it makes a cool demo, but tiring experience long term.


Paul
Paul