Settings for older JBL MR Series and Yamaha PS4500 amps

Phuketian

Hi, I have searched the past posts and read the FAQ's etc, but as I run several forums myself I understand that I may have missed a post that answers my request so please forgive me and go easy on the flaming.

I have inherited a system comprising of:

4 JBL MR838 Speakers
2 JBL MR 818 Subs

Powered by
2 Yamaha P4500S (Speakers)
1 Yamaha P5000S (Subs)

Only the P5000S is covered on the built in set up wizards on the DR PA.

Has anyone set up a similar system or set up each bit of kit individually and have the settings at hand?

Thanks in anticipation,

Dennis

The JBL website has absolutely no information on the MR800 series. There is a users manual for the MR900 series which was the model that followed the MR800 series and was basically the same but with a couple of bells and whistles. Check out:

http://www.jblpro.com/catalog/support/g ... &doctype=3

The manual has only basic specs but may help some with processor settings. I haven't had time to check out the amps yet.

Dennis

Dra

Welcome, about the only way to get flamed here it to present with ignorence AND apathy, so I wouldn't worry too much.

This is a relatively small community with only a small handfull of contributors. The rest mostly \"lurk\" about. You might get lucky on finding a user with your set-up, but don't hold your breathe.

Have you tried PSW or Harmony? There are a lot more users there, since they are geared towards all topics. We do a lot of custom work based on \"tuning\" sessions that I'm sure you saw in the Read me first section (start here).

We are glad to help, any way we can. How much have you used the DRPA previously?

DRA

Gadget

Interesting username... :?:

There will be no flaming done here...We run a pretty \"anything goes\" open minded forum here...unless you get belligerent...it's pretty hard to even get unless you start spamming and selling things...

As for your speakers....I don't think your going to find anyone here using those dinosaurs ... sorry... as I said, we try and keep it lite and informal here.

I always find JBL's specs amusing, Of course all I found was an old spec sheet for each. What exactly are you asking for? In the Read me first section, \"start here\"
http://www.dbxpro.com/forum/viewtopic.php?t=959
we delineate a pretty easy \"gain structure\" method that will set the sensitivity of any speaker/amp combo...This comes in handy when dealing with real world gear...like yours. Of course you also have the xover gain controls for further flexibility, but since the \"specs\" :roll: clearly indicate that the speakers are both 100db @ 1 watt 1 meter sensitive...

Depending on the setup...
Fact, the speakers can handle 250/500 watts with a peak (instantaneous) 1000 watts, you have 520/1440 @ 1Khz...so basically your kind of ok power wise, but you have no real headroom, Therefore I would adjust the LPF/HPF of the tops/subs @ 100 hz or over...this will give them more gas...if they don't have to reproduce the really low stuff.

As for the subs....the P5000 gives a spec of 2600 watts bridged @ 1khz (burst frequency) BTW their way of trying to \"discourage\" this practice, but not outright saying it...

The way to get the most out of the system then would be set an HPF of 40hz BW18 (since the 8-18's are older and 10db down @ 35 hz...) LPF of 100 hz LR24, or BW48 (BW48 if you intend to overlap the crossover points at all...) Some experimentation here is expected, and simple to find what works best...

Set up a 2X3 and set the subs together if at all possible, this would give you 3db of free power on the sub end...Bridge all the amps, (***NOTE in bridged mode the amps will draw much more current... so if it's questionable....****) and run the tops 2 per amp and the subs the same way... this will give you the most power and headroom. Since the tops are only ~ quasi trapezoidal, and (I have to assume a 90x40 pattern...?( not specified ) judging by the horn...which properly deployed would give you 180 degree coverage deployed in a stereo setup... I would flip one upside down on top of the other per side and in this fashion the horns would be in near proximity and hopefully couple, and limit the interactions...I say this because the horn will actually be on top of the 10\" with this setup???Hmmm

Welcome to the forum...

Gadget'
Moderator...and head goofball here

Dennis

The MR900 specs indicate a 100* X 80* pattern.

Dennis

Gadget

Looks like a whole different animal to me...well.. actually the MR926 looks very similar though...either way that spells even MORE possibility for interaction...and a ridiculous horizontal coverage for side by side deployment... what do you think Dennis?

Dennis

First of all, I am assuming the MR838 is the same pattern as the MR938 since that is all I have specs for. They were not designed for side by side and there is no good way to run two per side of the stage. Stacking them on top of each other might suck a little less but still has lots of problems. If you stack them horn to horn, they interact with each other less but but certain frequencies do not get full pattern coverage and tend to \"beam\" out in a narrower pattern, not covering all of the listening area (this isn't caused by horn to horn stacking, it is noticeable with a single horn as well). If they are stacked woofer to woofer, the horns will cover a wider pattern (vertical). That is the way a lot of larger systems are arrayed. Of course they are not using boxes with 80* vertical coverage and they are flying them as well. So the short answer is...I don't know.

Dennis

Gadget

That's what I was afraid of...no real good solutions here... what is the intended use for the system? Perhaps a single speaker a side and delay towers? Or in the case of a Disco application, perhaps a surround sound type app...

:roll:

Dra

What about horn to horn on their sides? 160* horizontal 100* vertical?
What about disconnecting one horn and rebalancing with the PEQ?
What about...?

DRA

Dra

What about a flown center cluster of 4 (or 3)?
What about a flown center cluster of 2 and then 1 L&R?
What about...?

DRA

Gadget

well there you go... a ton of possibilities to try...I can shoot holes in some of that though...bet those (being non flying types would benefit from the old adage...\"Jack up the radiator cap and drive a new car under it\" because flying hdwr to do it properly would be spendy...the horizontal placement sports the same problems Dennis listed, and that leaves flown center cluster of...2 (since 300 degrees is seldom useful... at least for me...) and or CTR/L/R deployment...
:? :shock: :shock: :shock: OOPS... guess the no flyware kind of negates that as well... :roll:

Phuketian

Hi guys I am impressed, what a nice bunch you are. Thanks a million for the answers so far.

I'll answer some of your questions:

The system was installed for a disco but the venue is being changed into a live music venue. I have bought stage monitors guitar and bass amps but the budget does not stretch to changing the main PA, so I've gotta work with what I've got for now.

We have bought a Yamaha MG24 MG24/14FX mixer, which has all the features I need and enough inputs, outputs and routing options.

I have not used a DRPA before, but am familiar with all it's component parts as separates. So I am competent enough to go through the set up as suggested in your excellent tutorial. I was just hoping that someone had set up something similar, so I guess I was being a bit lazy. (Put that down to me having the complete joy of living on the paradise island of Phuket in Thailand, hence the user name, that answers another question).

I will be getting down and dirty withe system today and will keep you posted on my attempts to tame this here beast and post my findings.

Dennis

And how might one pronounce \"Phuket\"?

Dennis

Gadget

There is a pill that \"may or may not\" help when you absolutely HAVE to perform... no matter HOW BAD you feel.. you take a \"Phuket\" all!! or see (NOT POSTED) alternative spellings....
And why DID Yamaha put out that *((#!)$)(^!#_!#&%+)@!#&_+)%@#^&_ mixer? hmmm did \"I\" actually say that? well if I did I have a good reason.. I assure you...I don't have a lot of good feelings about that system either... the subs will be ... well... less than sub like, the tops will be less than stellar, and the system as a whole will be only maybe... acceptable in nature... Good luck...we have given you as much pre-info as possible... we are usually not so disparaging, but it's going to be a difficult setup... use 2 tops whenever possible, 4 will elicit unpredictable results from side to side...
G

Phuketian

Dennis wrote:

And how might one pronounce "Phuket"?

Dennis

Phuket is pronounced Poo-Khet Dennis

Trev

Phuketian

Went into battle fully armed yesterday with the system and am still wrestling the beasty. Managed to track down manuals for the 818's and the MR838's too.
As the 838's are practically full range I have EQ'd them in isolation and used initially my imagination and then my ears for where I would like the subs to take over, still fiddling, just broke for lunch but it's sounding semi sexy.
Once again thanks a million chaps.

Gadget

I often do that very thing, then I can use the tops full range if the job calls for it...Then I can just set an HPF/LPF and run with subs...I figured you'd have to wrestle with them...

G

Phuketian

Well it ain't a conventional solution but I will update for future reference on how we tamed the beast in the next few days. Got the band coming in today for their first thrash, top tip for you all, I always find it's best to get the drummer in on his own and feed him first. (Also tell him to be there two hours before you actually need him).