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-   -   JBL 4328P Phantom Center (https://www.gearslutz.com/board/post-production-forum/1286357-jbl-4328p-phantom-center.html)

tha_lode 7th November 2019 08:20 AM

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?

Farhoof 7th November 2019 09:15 AM

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.

Jay Rose 7th November 2019 04:31 PM

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).

TheMuffinMan01 8th November 2019 05:14 AM

Definitely could be a phase issue, if you're running analog cables I highly recommend you check to make sure the connections are right.

tha_lode 8th November 2019 07:33 AM

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.

NReichman 8th November 2019 02:13 PM

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.

mrc 14th November 2019 09:33 AM

Sounds like a delay problem to me.

tha_lode 5th December 2019 01:38 PM

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.