Need new mid/highs, narrowed it down to 3,but shich are best?

[DJ Teknovibe]

I've been looking at some new mid/highs and have now finally, narrowed it down to 3 different ones, but which do you guys think have the best sound quality as well being loud as possible out of these :

 

1. JBL PRX-512M

http://www.jblpro.com/catalog/general/Product.aspx?PId=45&MId=3

 

2. DB Technologies Arena Pro 12 (not to be confused with the standard arena series, and now loaded with all rcf drivers)

http://www.dbtechnologies.com/mod_produkte.cfm?pgid=11&pugid=59&psugid=0&pid=202

 

powered by a

Crown XTi4000 amplifier

http://crownaudio.com/amp_htm/xti.htm

 

3. RCF Acustica C5121L

http://www.rcfaudio.com/vediMacro.phtml/sLang/EN/IDMacro/2522/menuAttivo/2366/m1/0/CompactSeriesC5212-CW5212/product.htm

powered by a

Lab Gruppen FP3400 amplifier

http://www.labgruppen.com/index.php/produc..._3400_features/

 

What do you guys think?

[TonyMitchell]

The RCFs and the dbTechs give you an extra 20 degrees dispertion, which is not to be sniffed at if you find yourself setting up on the long side of a rectangular room, as is the case with lots of hotel ballrooms.

 

Out of interest, what have you got on bottom end duty? I don't like mixing brands of box at FOH, just a personal preference.

 

Tony

[Trunker]

What are they for?

 

Be too loud for your bedroom, but would never fill the 02 Arena wuld they?

[DJ Teknovibe]

Well at present I've not got any subs, but using the the subs at the venue which are Wharfedale at the moment, but I'm going to be buying either 2 JBL SRX728S dual 18" subs or 4 DB Technologies Arena Pro SW18 single 18" subs. And using a TC Electronic XO24 loudspeaker management system, and powering the subs with either a Camco Vortex 6 if I buy the DB Technologies subs, and a Crown MA-5002VZ if I buy the JBL subs. Then venues are a pub and a village hall. The village hall is 35ft wide by 60ft long, and the pub's main floor where the system will be is 18ft wide by 55ft long.

[Dmills]

I've been looking at some new mid/highs and have now finally, narrowed it down to 3 different ones, but which do you guys think have the best sound quality as well being loud as possible out of these :

 

For what purpose and in what space?

 

The JBL is a 70 * 70 degree box, which is probably fine in some rooms, but would seem to be sending an awful lot of sound to bounce off the ceiling in others.

The DB is a 90 * 40 degree box, and is also 4Kg heavier then the JBL even without the amp (which may or may not be a consideration, depending on application).

The third is a 60 *40 box, that judging by that web page is designed for installed sound.

 

These are three totally different boxes, aimed at different applications, so we need to know about the room (how much dispersion do you need in each axis) and the application (installed, touring, pub band?), can you get the boxes above the audience tipped down? Do you need suspension points? Will you ever need to array?

 

May I ask how you narrowed the field to three such different loudspeakers?

 

We need more information!

 

Regards, Dan.

[TonyMitchell]

I'm going to be buying either 2 JBL SRX728S dual 18" subs or 4 DB Technologies Arena Pro SW18 single 18" subs...........

Then venues are a pub and a village hall. The village hall is 35ft wide by 60ft long, and the pub's main floor where the system will be is 18ft wide by 55ft long.

 

SRX728 boxes are not very portable. Do you really need 4 x 18" drivers (albeit not the most efficient drivers in the world) on bottom end in that small a space? My office is larger than that pub! What music will you be playing? Most village halls and pubs are close to residential buildings and there are environmental constraints, often enforced by sound limiters. Have you considered this?

 

Tony

 

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The third is a 60 *40 box

 

there appears to be a "W" (wide?) variant of that box that does 90H, Dan

 

Tony

[DJ Teknovibe]

Its dj music, vinyl, and I'll be playing oldskool hardcore rave with a lot of sub bass below 40hz so decided on the JBL or DB subs, and also I'll be playing hard dance music like techno etc....I wanted to get as loud a sound as possible because of the system I use to have and had to sell so now I'm building up my system again. I had 8k of JBL in the same village hall years ago with 4 JBL MP-418S subs and the sound was excellent. We cracked the village hall's wall though due to the severe sub bass in that tiny hall. Pulled the speakers away in the morning and found a crack in the brick wall and brick dust everywhere. The wall had to be rebuilt due to structural damage. So now I wanna go for some better, more gutsy, more powerful subs so (even though I won't have it was loud due to not wanting to crack the wall again) I've got enough poiwer to do very large halls if I want. I'm not at all worried about size or weight of a sub cos my mates are gonna help me, plus I'll be putting 3" castors on the back as well with very short bolts inside the cabinet, then air sealing the holes I drilled with silicon sealent. I did that with my older JBL subs and it worked a treat. Just lift them onto their back and roll them. We got no stars to go up ever so thatrs ok.

 

 

 

I picked the 3 mid/high vabs because they're the ones that seem to give out the most spl according to their data sheets. The mid/highs will be ground stacked on top of the subs. If I go for the JBL subs, I might even get 4 of them in total so I can stand all 4 mid/highs on top of them, one on top of each sub. I made the choice of the C5212L RCF cab because of the 1db extra ouput (not that I'll notice that litle amount) and the slightly narrower dispersion.

[Dmills]

True, I only skimmed the data sheets.

 

How much ceiling height do these places have, and can you get the boxes up on stands and angled down (it really makes a difference)?

 

I am sort of leaning towards the DB box (as much as you ever can without getting loaners to compare (Your dealer should be able to help with this)), as IMHO 70V is far too wide for most such applications, and the other box looks like an install unit more then a touring one.

The XTi 4000 is however too small IMHO given these are 8 ohm boxes rated for 500W cont. 1KW programme, the XTi4000 into 8 ohms is only good for 650W/channel. Stick the FP3400 on there instead!

 

The only way to really know however is to talk your dealer into getting you a demo of each (With music of YOUR choice, if you let the manufacturer pick they will all sound wonderful).

 

Note that once you go wider then 60 degrees, the ability to array in anything like a reasonable way tends to go to pot quickly, and with 90 degree boxes, you would probably benefit from some delays back up those rooms if you are on the short side. 60 feet with reasonably even coverage is a big ask if the ceiling is low and you are running any kind of volume.

 

 

 

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That is a lousy way to pick boxes!

Now you say you are using 4 boxes? Are you doing this as an array (which points toward wanting 60 degree units) or as a couple of delays further back up the hall (where 90 degree boxes might be a better fit)?

Something else you will want to consider is the implications of the noise at work regulations, you as the DJ are classed as being at work while playing a party, so you might want to do the math on that.

 

Very big halls will need something else or multiple delays if they are to sound any good, a ground stack at one end will be dangerously loud close to, and will fall off far too quickly with distance to really work in a large hall with any of those boxes. Additionally the critical distance will be fairly close to the boxes due to the wide pattern (The distance at which the reverberant field exceeds the direct sound).

 

Now, If I was building an obnoxious loud rig, I would pick up a pile of second hand KF850Z on top of suitable subs, and run maybe two a side (they array well and are very respectable, but you will need more amps).

 

Incidentally, subs either side is generally a bad plan, it creates a summing zone down the middle of the space that tends to boom, much better to line the subs up under the stage in the middle (you might get some coupling that way as well).

 

Regards, Dan.

[DJ Teknovibe]

The ceiling in the pub is only about 8ft high and the village hall's ceiling is about 15ft high. The Crown does give out 1,200 watts per channeel into 4 ohms though. Though I tried out a Lab Gruppen LAB1600 a while ago with my Celestion cabinets I have at the moment and they sounded amazing, better than they had ever sounded before. I can get a Lab Gruppen FP3400 for £900 used, in excellent conditon and saw they sell for about £2,450 new so £900 is a bargain for a used one.

 

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I was intending of putting the whole stack on the floor, in the middle of one end of the hall because nearly everyone who attends my events (ravers) want to be near the stack and hear it as loud as can be. And there's always only about 200 people who come but we have good events anyway. I'd prefer to go with EAW KF850 cabs, I wanted that in the first place but the amps ro drive them would just cost way too much money, and it would be pointless running them off cheaper amplifiers. I'd need 3 amps to run a pair of KF850 cabs because they're biamped, and using the minimum quality that I would go for (QSC RMX series amplifiers) would still cost me in total, about £1,500-£2,000 using used amps.

[Dmills]

I'd need 3 amps to run a pair of KF850 cabs because they're biamped, and using the minimum quality that I would go for (QSC RMX series amplifiers) would still cost me in total, about £1,500-£2,000 using used amps.

 

I think you mean triamped!

 

But there is an easy way to cheat:

Wire them in parallel and run in mono, then something like a MA3600 on the top and mid drivers and a MA5000 on the bass and sub (The sub being the other cab in the stack).

Job done, and only two amps involved (Use something more modern, that combination weighs a ton)!

 

Two stacks will give you around 4 ohms, if you are prepared to run at 2, then you could run 4 stacks off the two amps (Make sure the air filters are clean and the fans in good order, and that the stacks are all 8 ohms or greater, I cannot be bothered to look it up).

 

That would stomp all over anything using small boxes like the stuff you suggested.

 

I would reiterate the real hearing damage risk inherent in letting the punters get up close to a system like this, we put crowd barriers a few meters away from our stacks for a reason (it tames the worst of the inverse square law). You do have a duty of care to your audience (And a legal duty to anyone working in the venue).

 

Regards, Dan.

[mervaka]

I'd be careful buying all those MH boxes. if you dont array them carefully, you're liable to get some nasty diffraction patterns. arraying is a black art to me, so its best left for someone else to answer the question of "how" ;)

[DJ Teknovibe]

Yeah sorry I meant triamped. But even running them in parallel I'd need 3 amps because there's low, mid and high. How would I run them off 2 amps?

[Rob_Beech]

I might have read this on a bad night.

 

 

What you want is a pair of High SPL and high quality boxes, with some form of yoke and massive stands. Simply put them up in the air really high and point them at the audience.

It's all to do with the inverse square law and right angled triangles and stuff.

Whether they're powered or not doesn't matter, if you go for powered subs, its sensible to go for powered tops too. unpowered subs unpowered tops makes sense.

 

Let's face it. This is a system that is going to be put into a venue, turn up as loud as it can possibly go and is quite frankly going to sound pretty rubbish close up due to the excess volume.

 

Stacking them on the subs will not work. You wont hear it past the first 3 people and it'll be too loud for the first 6.

 

Some other useful truths.

1000 watts, 650watts, just over 2dB. Not noticeable.

 

KF850 are a TRI-amp box, you'd need 3 amps as you say to run them. but then more amps to run the subs,

They're COMPLETELY unsuitable for your application, listeners are not designed to be within several metres of these boxes, not to mention if they are and you are there to turn it up as loud as you can, you'll cause serious and potentially INSTANT hearing damage and loss.

 

And finally, a pair of any of the subs mentioned in your other thread are not going to give you true sound reproduction below 40Hz.

4 Will struggle.

 

Rob

[DJ Teknovibe]

How about this :

 

Running the 2 low frequency drivers on 1 channel in parallel off the Crown MA5002VZ amp, then running the mid off the left channel of a Crown K2 amp, running at 800 watts into 4 ohms, and the high frequency off the right channel of the Crown K2 amp running the volume down a bit so the high frequency gets about 400-500 watts into 4 ohms. By the way if I did use the KF850 cabs then I wouldn't run them at full cos that would be silly. I've heard them before and a rave I went to only used 6 in the main arena which was about a 8-10,000sq ft arena, and the sound was f**king amazingly loud. Just from 6 of them KF850 cabs. And they were suspended about 15ft in the air on gurders.

 

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Ok, I've come up with what seems to be the best idea. Power both low frequency sections off a bridged Crown XTi-2000 amplifier giving the low frequency, 2,000 watts rms into 4 ohms bridged which leaves me headroom.

 

Then powering the midrange sections off the left channel of a Crown XTi-4000 amplifier giving the midrange section 1,200 watts rms into 4 ohms which gives me 400 watts of headroom

 

Then lastly, powering the high frequency sections of the right channel of the Crown XTi-4000 amplifier mentioned above, giving the hgih frequency section 1,200 watts rms into 4 ohms, which gives me 800 watts of headroom.

 

How does that sound guys?

[Dmills]

In the context of a ground stack without the audience at a safe distance, I would shy away from the 850 as well, but if working in a more sane way was acceptable....

2 amps gives you 4 channels to play with, so (1 for the tops, 1 for the mid) = one amp, (1 for the bass and one for the sub) = the other amp, but as Rob says, not without some crowd barriers (and/or a flown array, probably ruled out in your pub with its 8 foot ceilings).

 

Getting the boxes way up in the air is indeed the key to covering a long room with only a few boxes, ground stack really will not do it.

Granted that a KW is only 2db more then 650W, but I was not thinking about louder so much as reducing the amount of clipping going on (and thus extending the life of the tweeters).

 

You might get better input on one of the DJ forums, this place is mostly theatre types (Hence all the worry about comb filtering), I get the feeling that speech intelligibility and a natural sounding rig is not the objective for your application?

 

Ref 40Hz subs, the only way you will get there is either some sort of bandpass box (but then you need something else below the 12), or just possibly horns, but you will need a lot of mouth area.

 

Do give the crowd safety issue due consideration, tinnitus is not nice, and you can do a lot of damage very, very quickly with these sorts of rigs. Just because the crowd want it loud does not imply that they have a understanding of the dangers, so it probably is not informed consent. You as the system operator do have a duty of care here. I would also advise that you google for the term "Temporary threshold shift", for some interesting reading on loud gigs.

 

Regards, Dan.