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ncdrawl
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Small Room acoustics
Freako
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Re: Small Room acoustics

Very interesting! These facts tell me that I have been either rather good, or rather lucky in achieving a more than fairly good imaging, and depth/width of the soundstage due to the hard work I have done to make this happen. I have a 16' by 13' by 8' room, medium damped, and my speakers are "bookshelf" size, carefully tuned in the port because they are way to close to the back wall, and a good sub right between the side speakers. The side speakers have felt on the front, and are isolated from the furniture on which they stand, as are the sub from the floor. This good soundstage and imaging shouldn't really be achievable because the side speakers are so close to the back wall (5"-6", and the port pointing backwards) even though they are rather small monitors.

Thanks for the post!

ncdrawl
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Re: Small Room acoustics

http://www.diffractionbegone.com/

these work wonders too. (although I dont use them on my Audiokinesis Speakers because they are already correct in that regard) I do use them on my others(b+w 801s, etc)

Johnny2Bad
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Re: Small Room acoustics

Not a criticism of your post, just a heads-up.

I would like to suggest that when you include a link that does not go to a webpage, and in particular if it goes directly to a download, please say so. Also, mention what kind of file it is, and the size.

Not everyone has proprietary applications, some people are still on dialup, and there's the poor phone users who pay by the megabyte to think of.

Of course, I can see that it's a link to a PowerPoint presentation from the url which ends .ppt
But, not everyone is as well versed in file extensions.

Something like:
[Your Link]
Microsoft Powerpoint presentation, 384 Kb
... would have been perfect.

Thanks for the informative post.

Buddha
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Re: Small Room acoustics

Freako, do you notice any difference with the guitar in or out of the room?

How about your halogen lamps along the ceiling or the lamp in front of the couch having any impact when on or off?

Freako
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Re: Small Room acoustics


Quote:
Freako, do you notice any difference with the guitar in or out of the room?

How about your halogen lamps along the ceiling or the lamp in front of the couch having any impact when on or off?

Hehe, good question! Well, I don't often play loud, since my upstairs neighbours are total music/hifi-ignorants. Last time I played a terrific track (Safri Duo "Samb-Adagio" http://www.youtube.com/watch?v=b2hteWScCek&feature=related) rather loud, they knocked on my door withing 2 minutes, and complained that they "..could only hear bass"! What a shame, cuz it sounded awesome in MY apartment!

So in order to show a little bit of consideration, I don't play that loud too often, but when I occasionally do, the guitar is happy to sing along. Otherwise I don't notice anything but minor vibrations from it. Nothing I hear anyway.

I have wondered about the halogen lamps myself, but oddly enough, it makes no difference whether connected or not. I have tried to turn them off, and also to disconnect the transformer totally. No change. The lamp next to my coffee table is connected to a whole different group in the breaker box.

Grounding your equipment is a great thing

geoffkait
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Re: Small Room acoustics


Quote:
Grounding your equipment is a great thing

Well, not necessarily.

However, lifting the ground might be considered too, uh, advanced for this class.

Elk
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Re: Small Room acoustics


Quote:
However, lifting the ground might be considered too, uh, advanced for this class.

DUP's typing fingers must be trembling. One of his favorite topics; the idiots that lift grounds.

geoffkait
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Re: Small Room acoustics


Quote:

Quote:
However, lifting the ground might be considered too, uh, advanced for this class.

DUP's typing fingers must be trembling. One of his favorite topics; the idiots that lift grounds.

Geez, I'm kinda sorry I missed that.

Elk
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Re: Small Room acoustics


Quote:
DUP's typing fingers must be trembling. One of his favorite topics; the idiots that lift grounds.

Geez, I'm kinda sorry I missed that.

Trust me, you are lucky you missed it. The signal to noise ratio was low.

Orb
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Re: Small Room acoustics

Hey ncdrawl thanks for that mate, some of it Gedlee has mentioned before, but there is definitely some intereting new comments and expansion of information in others.

One area of psychoacoustic that stood out was his mention of recent work relating to time considerations and diffraction/reflections.
Very interesting that the new work (of course it needs to be seen though) suggests that we are definitely sensitive down to 1ms beyond most assumptions made for the case of masking in general and measurements from spectral analysis.
Page 8 of presentation.
Maybe that has already been released as I cannot tell when that was added to the presentation.

While the new ear model study at MIT/Peabody Laboratory of Auditory Physiology scope did not include this, I do wonder if their investigation/modelling could tie in with the greater sensitivity than spectral analysis indicates (if the work commented upon by Geldee is validated with regards to his comment about psychoacustic masking in the time domain being poorer to an important threshold).

Part of the proposal from MIT/Peabody Laboratory of Auditory Physiology includes;

Quote:
The contribution of TM waves to amplification is expected to be significant only in the region where the two waves have comparable velocities and are likely to be out of phase with respect to each other.

Just to recap their conclusion (bear in mind that there is still a lot of work to do with further studies)


Quote:
We have demonstrated that radial displacements of an isolated TM excite waves of motion that propagate longitudinally with velocities similar to those of the BM traveling wave.
Analysis of physiological loading effects of the hair bundles, the limbal attachment of the TM, and fluid viscosity in the subtectorial space suggests thatTMwaves also can propagate in vivo.
Because these waves can stimulate hair cells and interact with the BM traveling wave, they constitute a distinct mode of motion (10, 45) that can have a significant effect on cochlear tuning and sensitivity, thereby fundamentally changing the way we think about cochlear mechanisms.

Thanks
Orb

geoffkait
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Re: Small Room acoustics


Quote:
Hey ncdrawl thanks for that mate, some of it Gedlee has mentioned before, but there is definitely some intereting new comments and expansion of information in others.

One area of psychoacoustic that stood out was his mention of recent work relating to time considerations and diffraction/reflections.
Very interesting that the new work (of course it needs to be seen though) suggests that we are definitely sensitive down to 1ms beyond most assumptions made for the case of masking in general and measurements from spectral analysis.
Page 8 of presentation.
Maybe that has already been released as I cannot tell when that was added to the presentation.

While the new ear model study at MIT/Peabody Laboratory of Auditory Physiology scope did not include this, I do wonder if their investigation/modelling could tie in with the greater sensitivity than spectral analysis indicates (if the work commented upon by Geldee is validated with regards to his comment about psychoacustic masking in the time domain being poorer to an important threshold).

Part of the proposal from MIT/Peabody Laboratory of Auditory Physiology includes;

Quote:
The contribution of TM waves to amplification is expected to be significant only in the region where the two waves have comparable velocities and are likely to be out of phase with respect to each other.

Just to recap their conclusion (bear in mind that there is still a lot of work to do with further studies)


Quote:
We have demonstrated that radial displacements of an isolated TM excite waves of motion that propagate longitudinally with velocities similar to those of the BM traveling wave.
Analysis of physiological loading effects of the hair bundles, the limbal attachment of the TM, and fluid viscosity in the subtectorial space suggests thatTMwaves also can propagate in vivo.
Because these waves can stimulate hair cells and interact with the BM traveling wave, they constitute a distinct mode of motion (10, 45) that can have a significant effect on cochlear tuning and sensitivity, thereby fundamentally changing the way we think about cochlear mechanisms.

Thanks
Orb

Geez, that's some pretty heavy duty jargon. Hmmmm....I wonder if all this technical analysis actually hides the truth. I can't help thinking this is the revenge of the nerds, audiophile style.

Drtrey3
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Re: Small Room acoustics

Keld, it is the hats that make it sound so spacious. It must be the hats! 8)

Trey

Orb
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Re: Small Room acoustics

You could be right

Cheers
Orb

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