JBL LSR4300 auto adjust to room?

[DaveH]

JBL LSR4300 auto adjust to room?????

Has anyone seen these in person?
Is this hype or a new trend?
Wonderful that they "adjust" but do they
sound any good to start with.

(Is this already old news? Couldn't find any threads.)


October 7, 2005
Bringing new capabilities to computer-based project studios, post-production and broadcast facilities, JBL Professional has introduced the LSR4300 Series studio monitors. With network intelligence, and a new automated version of JBL Professional's RMC Room Mode Correction system, the LSR4300 Series adds functionality to computer production systems while overcoming room-related problems that have plagued engineers and project studios.

[tubehead]

I'm interested in these too!

[Ethan Winer]

Dave,

> Is this hype or a new trend? <

I have to say Hype. There's no way to counter a room's influence because what a room does changes drastically over distances as small as an inch. EQ such as what's built into those speakers can reduce some of the most blatant low frequency peaks a little, but it does nothing for nulls or ringing, and those are at least as important as the peaks. Maybe even more so. The text below from my Acoustics FAQ explains the main limitations of active room correction.

--Ethan

Another common misconception is that equalization can be used to counter the effects of acoustic problems. But since every location in the room responds differently, no single EQ curve can give a flat response everywhere. Over a physical span of just a few inches the frequency response can vary significantly. Even if you aim to correct the response only where you sit, there's a bigger problem: It's impossible to counter very large cancellations. If acoustic interference causes a 25 dB dip at 60 Hz, adding that much boost with an equalizer to compensate will reduce the available volume (headroom) by the same amount. Such an extreme boost will increase low frequency distortion in the loudspeakers too. And at other room locations where 60 Hz is already too loud, applying EQ boost will make the problem much worse. Even if EQ could successfully raise a null, the large high-Q boost needed will create electrical ringing at that frequency. Likewise, EQ cut to reduce a peak will not reduce the peak's acoustic ringing. EQ cannot always help at higher frequencies either. If a room has ringing tones that continue after the sound source stops, EQ might make the ringing a little softer but it will still be present. However, equalization can help a little to tame low frequency peaks (only) caused by natural room resonance, as opposed to peaks and nulls due to acoustic interference, if used in moderation.

[brucegel]

Really just more marketing voodoo.By the way Ethan, I spent many holidays in Danbury.

[jayman]

I personally don't think it's marketing hype. I just got a pair of JBL LSR6328's which have a more primitive version of this room compensation thing. Basically it's just compensating for the main mode in your room, it's not creating an entire curve. It really does work for me, and I have to say, these monitors rock! Granted these are not the ones in this discussion, they're kind of the big brother, but I had to say something when you all were saying it was just hype and marketing. It isn't for me. Read the reviews on the 6328's, everyone agrees that it really does tighten up the bass in the mix position. For me it did.

j

[azwun25]

just heard these yesterday and i must say..i thought it was hype but these monitors sound great..i heard the 6" version by the way.

[brucegel]

Really no need for the value added eq since it really cant do what it purports to do.They are just trying to come up with a way to steer you in their direction.No problemo with that if what they are doing is sound physics but it aint. Shame on jbl marketing tutt

[jayman]

There are MANY pro rooms that eq their monitors. The feature on the JBL's is doing much the same thing, only it's just taking care of the most prominent room mode; and it happens to work. Have you listened to these monitors and found the feature NOT to work? I think you should give them a listen and try the room mode correction before you shame on them.

j

[brucegel]

The technique is bass ackwards.Design or augment your room not fix it in the monitor.When the room is right lots of monitors will sound fantastic...particularly in the mid and far field which is where the final analysis is done.

[azwun25]

this feature is not designed as a substitute for a properly treated control room nor is marketed that way. there's alot of guys doing pro-level work out of much less than perfect rooms, this feature is designed for those that maybe unable to treat there workspace properly. i spent some time with jbl reps last week, i heard the monitors demoed before and after the feature was used and it does do what it says it does, its not an end all solution as it only corrects the worst mode in the space effectively. example..they put the monitors on and they sounded a little muddy in the low mids and i wasn't that impressed...they used the sweep and sure enough it corrected the mud in the 400hz-500hz region and everything seemed to be in its proper place. they are by no means equivalent or a substitute for a well treated room. they definitely good sound in a good price range IMHO.

[brucegel]

But you do see how with cart before horse marketing the world inexhorably inches away from reality don't you?And no one wants to take responsibility for the twists.Sell it first, check for accuracy later.

[brucegel]

If that statement appears at the begining of their literature and in ther ads then I apologize for my statements.Buried on page twenty will not count.

[azwun25]

Originally Posted by brucegel

If that statement appears at the begining of their literature and in ther ads then I apologize for my statements.Buried on page twenty will not count.

agreed

[DaveH]

Thanks for responses.

First because of 20 days to first response
I though this was a “dead” thread.

Next I’ve been doing 18 hour days for awhile now.

Originally Posted by Ethan Winer

Dave,
> Is this hype or a new trend? <
I have to say Hype. There's no way to counter a room's influence because what a room does changes drastically over distances as small as an inch. EQ such as what's built into those speakers can reduce some of the most blatant low frequency peaks a little, but it does nothing for nulls or ringing, and those are at least as important as the peaks. Maybe even more so. --Ethan

Ethan, thanks for detailed information and link. Yes
this does make sense. I have an electronics lab here as well
and have “seen” nulls in a room on a scope.

Because I am an “electronics” type I don’t know what you call it
but I have also “seen”/heard the results of what I would a “beat frequency”
which is the result of two interrelated frequencies at certain spots
in a room peaking and null-ing at a slow rate. (I don’t know the name
of this acoustic phenomenon).

Anyway at first I got excited about the idea of this new speaker system
actually working. But could quick see that it would only take care of
“blatant” issues. (At least from an intellectual standpoint).