JBL Synthesis - Something BIG is on its way...

[Mr. Widget]

Interesting filters.


I'm curious what the phase response of that band pass looks like...

My thoughts as well...

I guess the proof is in the pudding.


Widget

[JBL 4645]

If all frequencies within the narrow LFE.1 range can be displayed with minimal loss as possible wouldn’t the amplifier then need less to produce those frequencies under excessive amounts of power?

I’d stack the other sub up front and see what the trade-offs are or place it above the other sub with a reinforced bit of timber and place it or the two subs in-between the left/centre and centre/right kinder like a Baby Boom sub bass channel of the 1970’s.

Why not lift but one of the subs and place it on blanket outside in the garden and test its frequency response with lesser boundary effect to curse cancellations.

Is the sub not following this plotted curve response?

grumpy

Was pink noise used for the outputting of the two subs and do they each have there own EQ or maybe that’s a question for Dome?

I’m sure the issue will be resolved before the end of the month with flying colours of uncoloured frequency response that is smooth like a baby’s silky bottom.

[grumpy]

Sounded more like an MLS type signal. My guess, trying all these other things... ain't gonna happen. I believe the deviation from the curve was
intentional based on Chris' experience, the room, and TD's prefs. I don't recall if there was separate EQ per sub... seemed there -could- be from
the L.A. configuration diagram and individual drives to each sub amp.

[JBL 4645]

Doesn’t JBL have room where they can place false walls up and conduct simulated tests to see how the problems can be addressed with some difficult home/rooms?

[grumpy]

Simulated, Schmimulated... I offered to do a long-term burn-in test of the Everest
Synthesis system in a real home environment (mine) ...
which was responded to with a well-practiced eye roll.
(apparently, there are lots of volunteers)

[jblsound]

Doesn’t JBL have room where they can place false walls up and conduct simulated tests to see how the problems can be addressed with some difficult home/rooms?

The various Harman listening rooms (Northridge, Michigan, Europe) can be adjusted to simulate any possible home enviroment, according to Sean Olive.

[JBL 4645]

The various Harman listening rooms (Northridge, Michigan, Europe) can be adjusted to simulate any possible home enviroment, according to Sean Olive.

Is that so are there pictures of this room at Harman?

So there must be computer model that can also work this out or is that early days?

Simulated, Schmimulated... I offered to do a long-term burn-in test of the Everest
Synthesis system in a real home environment (mine) ...
which was responded to with a well-practiced eye roll.
(apparently, there are lots of volunteers)

What do you mean by volunteers? Dedicated people who don’t mind?.. because I know a few that would be board to tears within a few minutes.

Me I don’t mind I can play sound over and over if its an interesting sound that doesn’t boar you!?

[boputnam]

There's another possibility... these are all JBL-Synthesis components... whose responses may very well already be preset somewhere in the software of the measurement system.

Yeah, I'm betting that is correct. But, even with my wonderful VP7212MDP's, which are astonishingly flat right-out-of-the-box, they are improved with some modest (and very few) filters we now use as a preset.

The one thing I recall is that each of the system components and the system itself had to be identified to the DACS before the process was initiated. For example, it was important to identify S1S-EX rather than simply S1S, or, worse, "subwoofer," etc. I suppose the DACS could read/identify the SDP-5 and SDEC-4000P/X units via the network interface, but not the loudspeakers or amps. It needed to be told in order to access the right profiles for the compiler.

Yeah, Doug - I'm sure that was a crucial part of the processing.

I guess the proof is in the pudding.

And, this pudding seems a good batch!

My guess, trying all these other things... ain't gonna happen.

:dont-know

Thanks, guys for sharing this - it's all hella interesting and very new to me, Mr. 2.0 Man. Keep the reports coming!

[JBL 4645]

Wouldn’t you also test frequency response from decoder AVR/AVP to analyzer to see if there is any loss because it should be flat before being presented to the amplifiers?

[grumpy]

If it was in a test/certification lab, or there was something measurably or audibly amiss...
perhaps.

[JBL 4645]

There’s chart that shows how the Dolby process goes though the many stages from dubbing theatre to soundtrack to cinema from an optical process the evolution of the soundtrack to what an audience finally hears in the cinema.

I can’t seem to find the white paper that I have that shows the frequency response. There are others? Mind you its dated back to around late/early 1980’s 90’s.

http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/53_EvolutionOfSound.pdf

[jblsound]

Is that so are there pictures of this room at Harman?

http://seanolive.blogspot.com/2009/0...reference.html

http://docs.google.com/Present?docid...7p2_85fxbrc4d7

[nlsteele]

Is that so are there pictures of this room at Harman?

http://seanolive.blogspot.com/2009/0...reference.html

http://docs.google.com/Present?docid...7p2_85fxbrc4d7

[/quote]


Thank you so much for these links! This will go a long way toward showing the wife my vision...

[JBL 4645]

Thank you so much for these links! This will go a long way toward showing the wife my vision...

Well the first link is dodgy I mean dodgy. It starts snowballing the pc with the same link over and over and its pain! Its fanging me to the teeth.

[Hoerninger]

... dodgy...

Try this one:
http://docs.google.com/Present?docid...&skipauth=true
or Download-link (12.2 MByte)

A new Reference Listening Room for
Consumer, Professional & Automotiv Audio
Research

by
Dr.Sean Olive
Director of Acoustic Research
Harman International R&D Group

presented at AES Munich Convention May 2009.
___________
Peter