Rational Acoustics



Kip Conner
January 24th, 2009, 08:06 PM
I have a client. I tune his P.A., we sound check, we begin show, I leave. Each time I have come back with some time for the closing of said show to find he's engaged that pesky sonic maximizer. First off I think to myself that I'm not tuning the PA the way he wants it with extreme high and low shelving that they the BBE provides. Then it occurs to me that he's changing the sound of the PA due to fatigue of his ears and just wants to hear something different. The end result is always a great sounding band, but buried vocals because of the altered eq of the PA.

I just don't trust a device that adds harmonic distortion to the PA. I put the device under test to what it actually does the Phase and Frequency response of the signal.

What do you guys think about this piece of gear? I don't get it.

Arthur Skudra
January 25th, 2009, 01:57 PM
I don't think much of devices like this, though years back I used it sparingly as an effects return to try to improve worn out tape tracks.

Harry Brill Jr.
January 25th, 2009, 09:32 PM
I don't think the BBE unit adds harmonic distortion at all. That's the Aphex Aurel Exciter you are thinking of. The Sonic Maximizer is supposed to correct for phase shifts and such. How it can accomplish this I have no idea so it's still snake oil as far as I can tell. In regards to the Aphex, the effect is real. I certainly wouldn't apply it to the entire PA though. Just like any effect it should be applied sparingly to a particular instrument. There is an effect out now (can't remember the name but someone will chime in) that adds harmonic distortion in the lows/ low mids that would indicate a fundamental that isn't actually there. It tricks the brain into thinking there is very deep bass present even if the speakers can't reproduce it. The old Ampeg SVT rigs worked in a similar way. The 10" drivers don't (re)produce the fundamental but the notes are clearly heard and recognized.

Lee Richard
May 5th, 2009, 09:37 AM
That's the Maxx Bass product. Gives that percieved deep bass that makes us think we hear it, without it actually being there. Great for movie theaters and places with multiple sound systems separated by only a wall, so no deep bass vibrations get through.

PaulTucci
May 5th, 2009, 11:36 PM
Kip,

I happen to have an Aphex Aural Exciter laying around so I tested it. As one would expect, an analog device showed no latency. The Impulse Response showed 0mSec of throughput time even when engaged. The first harmonic, twice the frequency of the test tone was generated as were others. I imagine they would be even order/pleasant sounding harmonics of the fundamental. 4x, 6x, 8x, etc.

The BBE takes a different approach as I recall researching that one. It assumes that your PA has a problem that the BBE can solve by its processing. Of course, if your PA does not suffer from that set of issues, you have introduced a new set of problems. Some folks, like your customer, may find the new irregularities pleasing though. It worked for Hendrix. The phase distortion of the BBE would be curious to see, I agree.

Tucci

phasetransitions
May 7th, 2009, 03:14 PM
The BBE takes a different approach as I recall researching that one. It assumes that your PA has a problem that the BBE can solve by its processing. Of course, if your PA does not suffer from that set of issues, you have introduced a new set of problems. Some folks, like your customer, may find the new irregularities pleasing though. It worked for Hendrix. The phase distortion of the BBE would be curious to see, I agree.

Tucci

I recall BBE asserting the high are lagging the lows, to boot! I don't think anyone here with smaart experience would agree with that!

99% of loudspeakers accrue group delay at low frequencies!

PaulTucci
May 7th, 2009, 09:09 PM
Dr. Phil,

Because the high frequency driver is physically located behind the voice coil of a direct radiating box, doesn't that mean the highs are lagging?

Once again, the physical characteristics are overidden by unseen parameters that are measurable by Smaart and other such programs.
I am in agreement with your disagreement.

Defend well!

Tucci