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PostPosted: Sat Nov 25, 2017 2:10 am 
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Location: Strasbourg France
Hi Guys,

Long time lurker but first post. So please tell me if I break rules. Thx.

Helping a friend with is CR. Sizes are: 5.26m x 3.51m X 2.11m. We installed everything and with the NTI the response curve is in-between 2 Hz from top to bottom. Pretty good for a start with just a few clumsy foam pads he had. Now we want to soffit his Adam's S3-A's. Has anybody done it before? Could not find info on the forum. Horizontal, vertical? He's also using an Adam Sub, 12 I guess. Attached is a quick top view. Yellow triangle is 1.66m.

Thank you all for this great forum. Really cool stuff here.

Kind Regards

JC


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PostPosted: Sun Nov 26, 2017 4:52 am 
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Hi there JC. Welcome!:)

Quote:
We installed everything and with the NTI the response curve is in-between 2 Hz from top to bottom.
I'd really like to see that. Please could you post the actual MDAT file somewhere, so I can download it and analyze it. That's some achievement for a small room like that!

Quote:
Now we want to soffit his Adam's S3-A's. Has anybody done it before?
Not the S3A, but yes I have soffit-mounted the close cousin of the S3A: The Eve SC407. Same basic design, similar performance. Here's how it worked out. viewtopic.php?f=2&t=20471

Quote:
Horizontal, vertical?
I'd have to do a full analysis of the room to be certain, but my first guess would be vertical.

Quote:
He's also using an Adam Sub, 12 I guess
For that room, I would suggest using at least two subs, bot just one. You'll end up with uneven response artifacts from just one. The second sub can fill in those gaps, and smooth out the low end response across most of the room.

Quote:
Yellow triangle is 1.66m.
I'm not sure if you are aware of this, but you do not actually need to have your geometry set up as an equilateral triangle. That's one of those numerous acoustic myths that "everybody knows is the right way to do it", and you even see it in many text books, but in reality is not necessary. Yes, you do need to have both speakers the same distance from your head, but no, they do not also have to be that same distance apart from each other. Also, the apex of the triangle should NOT be in the center of your head; it should be about 30 - 50cm BEHIND your head. If the apex is in your head, then the acoustic axis of the speaker is aimed at your EYE, not your ear. The geometry should be set up such that the acoustic axis of the speaker is pointing at your ear, or just a little but outside your ear.

Please do post the MDAT file from the acoustic tests you did: I'm intrigued to see such those results.

- Stuart -

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PostPosted: Tue Nov 28, 2017 9:55 am 
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Hi Stuart,

sorry for the long delay before answering but I'm glad you chimed in. I can't send you the MDAT file right now, but all I can say is that we were all surprised by the curve and what we heard. In reality, looking closer to the data it's more like 3 dB's and in the highs it's more. Between 4 and 20k it is way more uneven. But a second analysis from another guy with other methods and equipment confirmed the "curve". Remember there is no real room treatment nor soffit mounting, just a few foams and vinyl shelfs with foam covering the vinyls. Room sounds surprisingly good with so little treatment. Not utterly good, nor gorgeous. It's just a good starting point. Still needs lots a treatments but should be very comfy to work in the end. Listening position would be between yellow and green triangle.
I've had and used Eve SC307. Liked them. Smoother and more "balanced" than S3's from memory. I've also read your topic about the 407. Should have a listen. Anyway my friend has this S3/sub setup and he'd like to stay with that right now. Will keep you updated asap. And thanks again for answering.

(first edit)
I forgot to say that from memory between something like 3.5 to 4.5m back from the front wall there was some phase and comb filtering issues but we'll sort that out.
(second edit)
I'm also glad that my friend considers investing in acoustics, aka his room, instead of gear :-)


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PostPosted: Wed Nov 29, 2017 11:37 am 
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Quote:
I can't send you the MDAT file right now, but all I can say is that we were all surprised by the curve and what we heard. In reality, looking closer to the data it's more like 3 dB's and in the highs it's more. Between 4 and 20k it is way more uneven.
Then there's something wrong, either with the way you did the test, or with the way you are interpreting the results. It's really, really hard to believe that you got the low end flat but the high end has large swings in it. That makes no sense, and I can't even think of any acoustic situation where that could happen. Something is wrong here. I suspect a flawed testing procedure. I'd really suggest that you should repeat the testing procedure, carefully Here's how to do it right: viewtopic.php?f=3&t=21122

Quote:
there is no real room treatment nor soffit mounting, just a few foams and vinyl shelfs with foam covering the vinyls.
Then the highs should be reasonably flat, and the lows should be uneven! It makes no sense at all that you could get flat lows and messed up highs with that type of treatment. I suspect there was either an error in the test procedure, or in the equipment, or in the interpretation of the results.

Quote:
Room sounds surprisingly good with so little treatment. Not utterly good, nor gorgeous.
That's a major indication that there's something wrong with your test results: A room that has flat response does not "sound" like anything at all! It certainly does not sound "good", and even less "gorgeous". Many people don't like the way a flat-tuned room sounds, because it is absolutely neutral, and has NO sound of its own. It sounds like "nothing". So if you feel that the room sounds nice, then that's a sure sign it is not flat.

What is the overall RT-60?

Quote:
Sizes are: 5.26m x 3.51m X 2.11m.
It's a small room with a low ceiling, the floor area is less than the minimum recommended for critical listening, and even though the ratio is reasonable, it's not really that good. In a room that size with minimal treatment, there would still be modal issues at around 82 Hz, where your 0,0,1 axial and 2,1,0 tangential modes line up nearly perfectly, plus another modal issue at around 98 Hz, where your 0,2,0 and 3,0,0 modes are right on top of each other, less than 1/10th of 1 Hz apart. I would also expect to see the typical floor-bounce dip at somewhere above 100 Hz., SBIR from the front wall, plus various other issues. None of those can be fixed by the treatment you have in there right now.

So please repeat the test, carefully, following those instructions. It's real easy, and only takes a few minutes to do. Then post the MDAT file, and I'd be happy to analyze it for you.

Quote:
nor soffit mounting
Then why does your diagram show soffit mounting?

Quote:
Listening position would be between yellow and green triangle.
That would not be optimal for that room. There's a process for arriving at the optimal position, and it won't be where you are wanting to put it.

Quote:
between something like 3.5 to 4.5m back from the front wall there was some phase and comb filtering
That doesn't make much sense! If you have a phase problem at one point in the room, then you have it at all points in the room! The phase relationship might change as you move about the room, but it will still be there, at all locations in the room.

Quote:
I'm also glad that my friend considers investing in acoustics, aka his room, instead of gear
:thu: Very much! However, if you try to treat his room based on incorrect acoustic analysis data, you could end up making things worse, not better. You really need to do the testing properly, and make sure it is correct, before proceeding to the treatment stage.


- Stuart -

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PostPosted: Thu Dec 28, 2017 5:07 am 
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You know, the more I think about this thread, the more seriously I'm doubting the claims made.

It's very strange that someone would claim to have achieved essentially expert professional level results in an untreated room: the type of results that normally only happen after a very careful and extensive design and tuning process for a very large room, yet the claim is that they got even better results purely by random chance, using " just a few clumsy foam pads " in a small room!? 8) :roll:

Getting a "response curve ... in-between 2 Hz from top to bottom" is one hell of an achievement, even for an expert studio designer and acoustician. Especially when the "clarification" then claims: "looking closer to the data it's more like 3 dB's and in the highs it's more. Between 4 and 20k it is way more uneven", which is totally backwards, and inexplicable, acoustically. Its always the low end that has the major issues, with the high end being flatter and smoother. I can't even imagine a scenario where the low end is flat to within +/- 1.5 dB with resolution of 2 Hz, yet the high end swings wildly up beyond 4kHz.

Add to that: " there is no real room treatment nor soffit mounting, just a few foams and vinyl shelfs with foam covering the vinyls", and then "Room sounds surprisingly good with so little treatment. Not utterly good, nor gorgeous. It's just a good starting point. Still needs lots a treatment". Sorry, but if you have essentially flat response (+/- 1.5 dB), then the room is going to sound exceptional, fantastic, better than the best. It will be way beyond "just a starting point".

Then there's total silence following my invitation to do show the claimed results, and also do a PROPER set of acoustic tests in the room, then post the actual data. It's been a month since the initial comment of "I can't send you the MDAT file right now,...", and no further response, even though I provided a link to a set of instructions on how to do the tests correctly, validly, and accurately.

My suspicions continue to grow with each day that passes without any posting of the actual MDAT file... I can run those tests in a few minutes, maybe a beginner would take an hour or so including setup and calibration, so the fact that we are not seeing any results after a month seems rather strange, and speaks volumes . . .

:)

- Stuart -

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PostPosted: Fri Feb 02, 2018 11:21 am 
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January 27 came and went... two months to reply. Two months to provide the proof of the very literally "unbelievable" claim. Not a single peep...

So I'm calling "fake news" on this one: I'm not buying a word of it. Nothing in the OP's claims is to be believed: Not a single word. +/- 2dB on the first try, with just bits and pieces of random stuff? Nope. Didn't happen. I didn't believe it from the start, but I gave the OP the benefit of the doubt, and the opportunity to prove his outrageous claims: He didn't even bother responding, least of all providing proof... Because there isn't any.

If you want to see how the ACTUAL process goes for treating ant tuning a REAL control room, take a look at this thread, currently in progress: viewtopic.php?f=2&t=21368 . That's reality, not fantasy.

Closed.


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PostPosted: Tue Mar 27, 2018 1:28 pm 
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... and March 27 also came, so that's now four months with still no response from the original poster... no "proof" of the unbelievable claims made in the first post. No REW data, no nothing. So I'm definitely calling this one as delusional trolling. Not a shred of truth to it.

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PostPosted: Wed Jun 27, 2018 3:26 pm 
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... and April, and May, and June... ans still not a peep. Total garbage claims by OP. Pure troll.

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