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Title: house system opinions/advice requested...
Post by: Steve Matthews on October 11, 2008, 09:07:39 pm
Hi folks,

I have an opportunity to act as house engineer at a new club opening here... Before I came along, the owner had already installed a large PA that consists of a combination of stuff he'd brought in and some gear that came with the room...

The room is about 65' wide and 110' long, with ~20' clear to ~4' of duct work, lighting and steel truss ceiling. No treatment as of yet. There is a stage about 3' high and ~20'x12' centered at one end, facing a long bar at the far end. There is a dance floor that's stage width and ~30' long...

I took a day inventorying everything; opening up cabs to check drivers and testing it out then, another day on Google getting the specs on what I could.

The owner wants to split the PA use between house/guest DJ's on weekends and bands, every couple of weeks. I am posting the system below and requesting constructive comments/opinions/advice on improvements/configuration, etc. So, without further ado...



- 4 bi-amp cabs (custom built by "Woods", whoever they are...)

They have a 90 deg. horn w/Emilar EC320a 8ohm comp. driver and a ????? 12" mid driver

- 4 Transparence TR15H2 m

Which are 8ohms and rated 700w rms

That's it for tops. They are currently flown ~15' high pointing down around the dance floor. Only one pair of the 'Woods' cabs, flown on either side of the stage, face down room. We can (and likely will) move some of these...

Subs: (holy cow!)

- 4 Cerwin Vega B36-A 18" horn loaded w/orig. drivers, ~10yrs. old

- 6 18" K151 'W' bins, loaded with JBL 2240H (600w prog.)

- 2 smaller 15" 'W' bins, loaded with JBL E140-8 (400w prog.)

- 6 unknown make, dual 15" (horizontally mounted, vented reflex. They look like these: m but there's no badge...)

These are placed as follows:

       -the 3 18" W bins and 1 15" W bin are stacked on either side of the stage.

       -the 6 dual 15" cabs are lined up side-by-each and built into a platform butted against the front of the stage

       -the 4 CV B36's are lined up in a row and built into a dance platform at the 'down-room' end of the dance floor and FACING the stage. Thus, demarcating the dance floor area...

All of this is powered by:

Power Amps:

-QSC EX4000 on 3 18" 'W' bins/ch. Therefore, only ~500w/cab

-QSC EX4000 on 2 cerwin vega B36A 18"/ch. Therefore, only ~600w/cab

-QSC MX1500 on 'Woods' high freq. 2/ch. Therefore, ~300w/driver

-QSC MX1500 on 'Woods' mid freq. 2/ch. Therefore, ~300w/driver

-Audiopro MOS 500 - on one 15" JBL 'W' bin/ch. It is 250w/ch. into 4 ohms. Therefore, well less than that on these 8 ohm cabs...

-Crest CA12 on 3 dual 15" subs/ch. Don't see how this even works, unless the cabs are an 8 ohm version, in which case, only ~500w/cab, for a sub (assuming it's the one linked) rated at 1500w rms...

-Behringer EP2500 on 2 Transparance tr15h2/ch. Therefore, only ~325w/cab

All of this has only a Furman X-424 crossover in 3-way mode and an Ultragraph Pro dual 31 band EQ for processing...

So, I'm going to refrain from commenting, or sharing my opinion for now, as I'd like to use this thread to provide the owner with an unbiased critique of this system. Then, based on your input, I hope to discuss some ideas with you guys, so I can begin the process of getting the most out of this system...

Also, there's been some discussion about selling part (or all) of this stuff and starting from scratch. So, feel free to suggest upgrades, reconfiguations, etc.


Title: Re: house system opinions/advice requested...
Post by: Tom Young on October 12, 2008, 03:29:14 pm

It's not a great PA by any stretch.

Aside from the question of how well the Woods fullrange ldspkrs are designed (including crossover) *and* how well they are aimed (to cover where they need to and not overlap, etc)..... you have a real hodge-podge of LF devices. Not sure they all qualify as "subs".

The dual 15 boxes you provided the URL for are basic, 'meat & potatoes' bass-reflex direct radiators.

The W's were (more than likely) designed by JBL and even though the K151's were the orginal driver and sounded sweet, higher power JBL 18's that were introdcued later were preferred by most endusers back when these cabinets were a hot commodity. 3 stacked per side would net you pretty solid response down to about 40 (maybe 36) Hz.

The Cerwin Vegas were loud but not otherwise very good.

So having this hodge-podge means you have questionable phase relationships going on between the different "sub" devices and their different locations. Having the CV's firing back towards the stage means you may have a null at some frequencies somewhere on the dance floor but they may also couple and add together (all the bass devices) around the dance foor (as well) at other bass frequencies.

Processing these for maximum response would be a nightmare(*): you would need different high-pass filters for each model of "sub", different bands of parametric EQ and different delay settings and different limiter settings (or limiting set for the weakest component in this combined group). So you need a DSP processor with X-many inputs by X-many outputs, partly determined by whether the system is in stereo (probably is ?) or mono.

If you got someone in with a good ("modern day", aka: complex) measurement system, plenty of exerience and a willingness to tackle such a beast...... this system could be made to work far better than it ever has. The starting point would be to test each driver for condition and polarity. Then aim them as they should be. Then combine them properly.

This system will never behave like an intelligently designed modern day loudspeaker system can. But it could work OK.
Title: Re: house system opinions/advice requested...
Post by: Dick Rees on October 12, 2008, 04:33:31 pm
I think the operative term is "collection" rather than "system".
Title: Re: house system opinions/advice requested...
Post by: Steve Matthews on October 13, 2008, 12:11:30 am
Thank you Tom and Dick. I was hoping for at least one objective response before replying, so that I could approach the owner with it and Tom, you have delivered...

It's obvious that this 'system' needs much work, or replaced completely. I've talked to the owner about both options, but since he's gone to so much work getting this thing set up and the opening is this Friday, I can really use some back-up to help convince him that his success may hinge at least partly on the quality of his PA.

I whole heartedly agree with Tom's assessment. Mine was essentially: massively bottom-end heavy, grossly underpowered, under(no)processed, 'dog's breakfast' of a PA. When he fired everything up at once for a listen, my opinion was not improved. That's not to say parts of it couldn't be whipped into a passable system for the opening and improved after that. But, it's gonna be scary with quest DJ's on it until proper processing/protection can be added.

So, since I wrote the OP, I've jotted down a plan for next week. I'd like to share it here for comment...

-Tues. (Mon. is Cdn. Thankgiving)(days are short because I'm working my day job on afternoons this week):

-check x-over settings and wiring, amp wiring and polarity

-patch my o1v96 into house system using aux sends to feed various parts of the system for A/B tests

-with existing amp/cab config., compare Transparence tr15h2 with 'Woods' cabs alone to assess tops

-'Woods' are flown at stage for now, so run them with 'W' bins, then dual 15"s to compare FOH subs

-listen to CV's with tr15h2 and/or 'Woods' tops just to show the owner how 'bad' these subs sound compared to the FOH subs


-if listening tests justify it, move pair of tr15h2 to front and power with bridged PLX3002 (this is my amp)

-bring in my Unity PA and try U15P with best sounding FOH subs and compare against his tops
-if time, compare one pair of 'W' bins and/or 1 dual 15" sub against pair of Unity UCS1P subs


-assuming I have owner on board by now, re-assign amps as follows:

- 2 QSC EX4000       (try on 4 18" 'W' bins, 1/ch = 800w/cab, or ~1600w/cab bridged)

- Crest CA12       (try on 2 18" 'W' bins, 1/ch = 650w/cab, or ~1100w/cab bridged)

I can then swap these 6 amp channels to the 6 dual 15" front cabs (I'll have to check DC ohms first to determine nom. imp. to determine power delivered)

- Audiopro AP3000   (try on 2 15" 'W' bins, 1/ch = 475w/cab)

- QSC PLX3002       (try on 2 tr15h2, 1/ch = 550w/cab, or ~1500w/cab bridged)

- Behringer EP2500   (try on 2 tr15h2, 1/ch = 450w/cab, or ~1200w/cab bridged)

- 2 QSC MX1500      (leave on 4 'Woods' for now, maybe try 2 cabs with 12" drivers on bridged amp, which would be 750w/driver)

- Audiopro MOS 500    (relegate to booth monitor only for now)

This config. should get everything but the CVs (which go unused) driven with closer to appropriate power. Few of the available amps are good matches to any cabs; 1 cab/ch. is a bit underpowered in most cases and 2 cabs/amp bridged seems a bit high. But, I'll run the best sounding FOH subs bridged for the listening tests and maybe convince the owner that he can forego the others. Then, I'll repatch for 1 cab/ch. for safety with quest DJ's until proper processing/protection can be aquired.


- choose config, rewire to DJ booth, test

- move 'Woods' tops to dance floor if using tr15h2 for stage

- load Unity PA out in time for grand opening

Potential Issues
- impedance of front dual 15" subs: note power into each cab is dependant on nom. imp.

- crossovers: need 2-way channel for subs/tr15h2 and 3-way channel for subs/'Woods'. Maybe daisy chain?

- 90deg. horns in all mid/high cabs: comb filtering if arrayed.

- short on amps if want to run more than one type of sub at once (not recommended)...

So, there's the plan. Does it look reasonable? Particularily the amp assignments? If anyone can suggest improvements, it could really help me out seeing as time is so short...

With any luck, he'll be blown away with the Yorkville stuff and I can get him to sell off this rig and put in powered stuff...

Title: Re: house system opinions/advice requested...
Post by: Dick Rees on October 13, 2008, 02:31:34 pm
You've got a pretty thorough plan worked up.  The problem I see is the varying response of the mis-matched cabinets.  It seems as if you'd have to run several different system EQ's on them to get any kind of overall smooth response.  If they are in fact covering seperate areas with minimal overlap it shouldn't be as much of an issue, but overlapping  coverage from the different cabinets would seem to be the primary problem.  Then there's the problem of power.......

Keep us posted.
Title: Re: house system opinions/advice requested...
Post by: Chuck Fudge on October 13, 2008, 06:18:04 pm
When you see the words "club owner" and "purchased system" in the same sentence you know you are in trouble.
Title: Re: house system opinions/advice requested...
Post by: Steve Matthews on October 13, 2008, 10:06:09 pm
Dick Rees wrote on Mon, 13 October 2008 14:31

You've got a pretty thorough plan worked up.  The problem I see is the varying response of the mis-matched cabinets.  It seems as if you'd have to run several different system EQ's on them to get any kind of overall smooth response.  If they are in fact covering seperate areas with minimal overlap it shouldn't be as much of an issue, but overlapping  coverage from the different cabinets would seem to be the primary problem.  Then there's the problem of power.......

Keep us posted.

Thanks... As for all the mismatched cabs, my wish, for bands at least, would be to never run anything other than the best sounding set of subs, with the best sounding set of tops at the stage, as determined during the listening tests.

I think, for the size of room, either the 'w' bins (btw, they have that classic "JBL W Series" badge on them, so I assume they are built to spec. just with the 2240's instead of the K151's...), or the dual 15s, should be more than sufficient... (I'm trying to ignore the CV B36's). As for tops, I had never heard of the Transparence 2-ways before, but what little I could find out, seems to be positive. It's just a matter of whether they can keep up with the subs.

But, I have this owner who brought all this in and he may balk at not using it all. That's why I'm hoping that getting each group of cabs fired up with proper power, as well as comparing them to the weaker choices and also, my (relatively) tiny Unity system, will provide him with some perspective on sound quality and coherence, while also helping me familiarize myself to everything. Thing is, I'm thinking in terms of live band SR only and he wants tons of SPL on the dance floor for the DJs.

What do you think of the idea of using something like an o1v96 for processing this system? With the addition of an ADA8000, you could divide the system into 'zones' using the buses. Then, program different scenes for DJ use, or live SR.

With 12 outs, the DJ scenes could feed additional drivers on the dance floor and have the PEQ's adjusted for that sonic mess. The DJ would have a single (or stereo, or surround, for that matter) tie-in, via a patch bay, to the v96 for his rig and the actual PA settings (especially max. output) would be locked out. Then, it should be easy - even between sets, during a live show - to swap scenes back into band SR mode, using only a FOH system...

I already use the PEQs and ch. delays for x-over filters on the v96. It would take time to dial everything in initially, but it should be possible to fore-go any other DSP, except maybe a couple of 31 band EQs for guests engineers...

Just a couple more questions for those in the know;

Does anyone know anything about these Emilar drivers? I can't find any specs on them.

Also, the Transparence 2-ways; anymore feedback on them? Or, Belisle Acoustics in general?

Also, I've been talking to the owner about slowly selling and swapping this system out for a Yorkville system. When we're talking about getting the amount of bass this guy would like (that being based on 10 18" and 14 15" drivers!! albeit, currently, all underpowered). What would you recommend; could 4 to 6 LS800P per side, or a somewhat smaller number of LS1208's, or 4 to 6 UCS1P's per side keep up to any given group of subs, as described above? Which cabs and how many would you use?

For tops, I was thinking U215's, but I'm wondering if a pair would give me the coverage required. However, I'm wondering if a pair clustered per side might be overkill. So, I was thinking about 6 U15P; a pair per side, flown at the stage and another pair on the far corners of the dance floor that could be pointed down and in for DJ's, or rotated and delayed for bands... Any thoughts, keeping in mind the room size? Maybe 6 wouldn't cut it?

Title: Re: house system opinions/advice requested...
Post by: Art Welter on October 14, 2008, 03:56:57 am

Lots of questions, here’s a few answers:
Though none of the bass cabs are powered to death, doubling the power probably will not  result in 3 dB more output due to thermal compression, and if the system is left unattended, much more power may be an invitation to a coil barbecue.

Doing a mix of bass for recorded music, some pointed back on the dance floor may not be bad, though I would agree in trying to keep the majority similar if not the same for live music.

The Emilar drivers are probably OK if they have survived, they made some good sounding units that had less midrange than JBL or Altec, so sounded a bit more reserved, or “hi-fi” than others. Opinions on all the range of speakers you have in the club are somewhat irrelevant, since the speakers are old, it is how they measure up that is important, and it looks like you’re the man that’s going to do the measuring.

You could probably make the room sound better with all matched Yorkville or other stuff, but if you array and eq the present pile correctly you could come up with a good sounding system, or not.

If not, hopefully you did your best and got paid for your time. If you get it to sound good with the present aggregation, the owner may have more money to hire better entertainment, which can make a hell of a lot more improvement in sound than a system change will, and if you continue working there, you will appreciate it.

Can be a chicken and egg deal, but you may be better off getting it flying with what is there than pushing for more than can be afforded.

Good Luck!