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SAM Profiling ourselves...
#1
Suggestion for future update / tweaks... Perhaps we could acquire the SAM profile of our own speakers ourselves?

I'm guessing it's not as simple as plugging in a USB microphone to a PC that sits next to the speakers woofer and running some software to do the mapping but it can't be that far off the mark. And it's how all room correction is done if I'm not mistaken.

Doing it to our own speakers would negate any differences within the manufacturing process (no 2 speakers will truly sound the same as each other based on manufacturing, room temperature, life span, air pressure etc etc...)

You would also get a wealth of data from the community and the ability to share results and SAM profiles to mix and match.

And could be a fun toy to play with!

Just a thought.
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#2
I believe it involves more than using a microphone. Mathieu told me at the OAC that measuring everything they need takes a group of engineers 3 full days in the lab.
If I understood correctly it would be unlikely that any owner would have the correct instrumentation or expertise to do the work.
Devialet Original d'Atelier 44 Core, Job Pre/225, Goldmund PH2, Goldmund Reference/T3f /Ortofon A90, Goldmund Mimesis 36+ & Chord Blu, iMac/Air, Lynx Theta, Tune Audio Anima, Goldmund Epilog 1&2, REL Studio. Dialog, Silver Phantoms, Branch stands, copper cables (mainly).
Oxfordshire

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#3
(30-Jul-2014, 15:17)f1eng Wrote: I believe it involves more than using a microphone. Mathieu told me at the OAC that measuring everything they need takes a group of engineers 3 full days in the lab.
If I understood correctly it would be unlikely that any owner would have the correct instrumentation or expertise to do the work.

I recall hearing similar from Mathieu. (Possibly when ear-wigging Mr F1eng’s conversation at OAC) Now, I do have an old microphone somewhere, but laser scanning kit to measure real time driver movement etc? I'll have a rummage 'round my garage to see what's lying around.....

It's very clever stuff, and well out of my league for sure.
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#4
Thinking about it, I did have a Technics graphic equaliser back in the 90's that did exactly this (frequency wise, not SAM obviously). This was used as part of a 3kw active PA system, with separate fan cooled Peavey power amps, 18" horn loaded bass bins etc. Now this was "professional" DJ'ing kit, not hifi (the word professional is in quotes for a reason, we did get paid for gigs but the term professional is stretching it a bit...)

Anyway, you could plug a decent quality Sure microphone into the graphic equaliser, it ran through a white noise / frequency sweep, and hay presto! it set itself up perfectly. The trouble is, it did not do this very well. The mid band frequencies were about right, but bass and treble were audibly miles out, so we then re-set up everything manually, by ear.

The point being, that the old Technics equaliser was indeed just a graphic equaliser, not capable of the phase correction, time correction and other trick stuff that SAM can do. So setting up something as simple as the Technics via microphone etc. should have worked quite well, but it still didn't. Getting something as sophisticated as SAM set up correctly, outside of dedicated custom designed and equipped facilities, would be at best, very, very difficult. I do wonder if SAM could be provided with some home configurable tweaks though (say, to slightly reduce bass at the speaker port frequency for example), to maybe address some of the boom issues that "large" speaker SAM users have reported? Just a thought.
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#5
(30-Jul-2014, 21:12)Confused Wrote: Thinking about it, I did have a Technics graphic equaliser back in the 90's that did exactly this (frequency wise, not SAM obviously). This was used as part of a 3kw active PA system, with separate fan cooled Peavey power amps, 18" horn loaded bass bins etc. Now this was "professional" DJ'ing kit, not hifi (the word professional is in quotes for a reason, we did get paid for gigs but the term professional is stretching it a bit...)

Anyway, you could plug a decent quality Sure microphone into the graphic equaliser, it ran through a white noise / frequency sweep, and hay presto! it set itself up perfectly. The trouble is, it did not do this very well. The mid band frequencies were about right, but bass and treble were audibly miles out, so we then re-set up everything manually, by ear.

The point being, that the old Technics equaliser was indeed just a graphic equaliser, not capable of the phase correction, time correction and other trick stuff that SAM can do. So setting up something as simple as the Technics via microphone etc. should have worked quite well, but it still didn't. Getting something as sophisticated as SAM set up correctly, outside of dedicated custom designed and equipped facilities, would be at best, very, very difficult. I do wonder if SAM could be provided with some home configurable tweaks though (say, to slightly reduce bass at the speaker port frequency for example), to maybe address some of the boom issues that "large" speaker SAM users have reported? Just a thought.

Nowadays in room frequency response even-ness computation for the bass is readily available in pretty well all home theatre processors and some hifi ones too.
I hesitate to use the word correction, since that is very difficult/impossible. Certainly impossible with a single subwoofer to do much other than approximate at 1 listener position. With 4 subwoofers it should be OK but I only have 1 and only use it for films. I have yet to hear such a "correction" device sound good to me here in my listening room.

SAM does not attempt room correction, as we know, for which I am grateful...
Devialet Original d'Atelier 44 Core, Job Pre/225, Goldmund PH2, Goldmund Reference/T3f /Ortofon A90, Goldmund Mimesis 36+ & Chord Blu, iMac/Air, Lynx Theta, Tune Audio Anima, Goldmund Epilog 1&2, REL Studio. Dialog, Silver Phantoms, Branch stands, copper cables (mainly).
Oxfordshire

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