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JBL 4328P Phantom Center
Old 7th November 2019
Gear Maniac

JBL 4328P Phantom Center

Hi guys.

I have a weird issue with my 5.1 JBL setup.
The speakers seem to be missing phantom center.
When playing a mono sound t.ex. voice overs through both speakers I can clearly hear both speakers play separately when sitting at correct distance instead of having the illusion of the voice coming from the center.
It partially feels like there is a level problem, but I have run the room correction tool, and it didn´t really help.

I switched to another pair of speakers (Dynadio BM6A) which did not have this problem.

Is this a classic problem?
Old 7th November 2019
Gear Maniac
Farhoof's Avatar

I'm guessing the room correction tool _is_ the problem. Setting different eq's on both speakers will introduce phasing issues (depending on the eq). This is a common issue. Try setting all settings to flat or if possible try a manual eq setting both speakers exactly the same.
Old 7th November 2019
Lives for gear
In a proper 5.1 mix, dialog and v/o come from the center speaker only... not (or only very little, for special circumstances) the LR mains. That's a different issue from phantom centers.

But if you're hearing mono-on-mains as two separate LR speakers rather than centered on the screen, turn off the eq. Still bad? Check the speaker phasing. If you're still not hearing phantom, either one of the speakers or your room's acoustics is the problem. (Acoustic issues can be asymmetrical absorption/reflection, or even something as simple as sitting too close -- i.e., not in a roughly equilateral triangle with the mains).
Old 8th November 2019
Gear Maniac

Definitely could be a phase issue, if you're running analog cables I highly recommend you check to make sure the connections are right.
Old 8th November 2019
Gear Maniac

Since just switching to another pair of speakers fixed the phantom center problem I´m confident that the cables are ok. Probably the room too.
I also tried switching phase on one side without the problem going away.
Old 8th November 2019
Lives for gear
NReichman's Avatar

The 4328s have a lot of settings, including delay. There's a way to clear the memory (manual is online). I would clear the memory of all the JBLs and then re-run the room calibration.
Old 14th November 2019
Lives for gear
Sounds like a delay problem to me.
Old 5th December 2019
Gear Maniac

After flashing all 6 speakers everything is fine again.

If anyone is tempted to do the same thing, be aware that you need a pc to do it.
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