I mention this now and then, but here's the data.
When re-decorating our music room, I placed a sub (AR-1 about 1956) in a dozen (or so) locations. These were mostly against the far wall but also adjacent along the sides a bit. The mic location was stationary where my chair would be towards the middle of the room.
The dB scale is not calibrated.
When re-decorating our music room, I placed a sub (AR-1 about 1956) in a dozen (or so) locations. These were mostly against the far wall but also adjacent along the sides a bit. The mic location was stationary where my chair would be towards the middle of the room.
The dB scale is not calibrated.
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Can't make sense of your first sentence.
I don't use the AR-1 in my every day system. Being a small box, it was useful for these tests.
For about 50 years and several crossovers, I've used about 135 Hz, 24dB/8ave, electrostatics mostly. And all kinds of subs. With cone mids, a bit lower would make sense.
Got it.
It is fair to say speaker location influence (within my set of test locations, room, absence of furnishings except for wall to wall carpet with underlayer, and using a "bookshelf" woofer on the floor) is substantial for every freq below 500 Hz but not much below 40.
B.
So, measurements follow theory and experience well. We see room mode dips and peaks below 100Hz, and some variation in amplitude of those because of different location of sound source. Above 150Hz variations are wider spread, Schröder effect weakening. Below lowest mode response is almost constant (one measurement being exception - why?)
Listener/mic location has much more influence on the response in modal range below Schröder.
It would have been nice to see the effect of multiple subs. I have tried it and results were not good in a small room, mode dominance is so high!
Listener/mic location has much more influence on the response in modal range below Schröder.
It would have been nice to see the effect of multiple subs. I have tried it and results were not good in a small room, mode dominance is so high!
I love seeing Schroeder referenced since it gives me a chance to mention that I saw him at Bell Labs (OK, his office was just down the hallway from mine).
There's no disputing the science, I suppose. The match of theory and practice "on the ground" in my room are, as Juhazi says, seems correct (as always with Juhazi).
But if you know your Schroeder freq (which I do not... but should), so what to do*? What do you do differently as compared to not knowing it? Acoustic interventions are very blunt tools.
B.
* folks with subs in the same box as their mids and tweets face certain compromises which folks with separately housed subs (like most of us) do not
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It might have been Olive & Welti... I had three subs in a small room, 2,5x4x2.7m One sub in corner, one at midpoint of long wall, third on top of bookshelf! It helped, second had no effect.
Oh yes, and Schröder limit is difficult to see/catch with measurements, there are so many other phenomenoms too showing up in measurements with long gating.
Oh yes, and Schröder limit is difficult to see/catch with measurements, there are so many other phenomenoms too showing up in measurements with long gating.
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