Delay set up questions

ecordeddie

Our gear is as follows:

Two JBL SRX722s (dual 12�s and horn) and two JBL MRX518s (dual 18�s) all driven by Crown amps

Stereo system…Behringer Eurodesk 24 channel mixing board, 8 channel Alto compressor/gate (to kill some ringing toms on the drums) and a Lexicon MX400 FX processor. That’s it…simple system.

Three vocal mics…. two SM58s and one Audix

No stage guitar or bass rigs….we all use floor board pedals direct to the mixer.

Two Mackie powered monitors for stage side wash.

One Xti1000 in stereo on the horns 8 ohms - 275 watts per side
One XTi4000 in stereo on the mids 4 ohms - 1200 watts per
One XTi4000 Bridge on each sub 4 ohms - 3200 watts per

...and of course the DriverackPA....

I've set the gain structure using pink, set up the limiters & input the Wizard items etc....

Now it's on to the delay....

Most of the rooms we are in are about 30 to 60 feet deep.

Can you give me a general delay set up to start with?

Thanks,

Dra

Have yo been to the JBL site and looked for the delay settings (and PEQ settings) for the 722's? FYI, the room has nothing to do with it.
I believe the delay method that Gadget recommends is (I think) in the RMF section.

DRA

Gadget

Also depends on the Xover used...I'd bet they aren't more than a few milliseconds delayed (tops)..maybe 8-9ms And no... I'd stick with the PX... set the subs up (anything below about 170hz by ear...
G

ecordeddie

Dra wrote:

Have yo been to the JBL site and looked for the delay settings (and PEQ settings) for the 722's?.....
DRA

Yea....the tunings page won't load for the SRX700 series....

ecordeddie

Dra wrote:

I believe the delay method that Gadget recommends is (I think) in the RMF section.

DRA

ahhhhhh....what's the "RMF" section???? "realy munchy fries"..."roasted marshmellow fudge"??? ...OK seriously what the heck is RMF?

Dra

READ ME FIRST. Lotsa good stuff there. It is not rules of the forum (like you might expect).

DRA

uhdinator

Delay is used to delay the output of your top cabs so your folded horns
are time aligned and you here the sub and HF at the same time.
This makes your system sound tighter.

You don't have folded horn subs. The only other reason to use delay
is to delay top and bottom equally to align with back line of stage so you
hear guitar and bass amps at the same time as the pa cabs. And that
will only help if your instruments amps are less then 10 feet or so behind
your PA cabs. (if you have the DR260 then you can delay your PA
a 1/2 mile if you have a stage that big)

Gadget

Again my young padawan you seem to be behind the curve... you see, had you read the RMFBP section you would know that the LR 24 xover creates a 7.5 ms delay from the tops to the subs...this has been proved using SMAART and we have been calculating this into the formulas since it was proved some 3 years ago... The other crossovers have yet to be determined but again... had you read the RMFBP section you would know WHY we spec the LR 24 for system HPF and up... BTW the proscribed HPF for most systems with subs is BW 18..(even those without subs... check the RMF section to find out why)
G

uhdinator

Thanks,

So I have front loaded Yamaha 215 Subs and I am using the BW18 at 35-40HZ and the L/H x over point 95-100 HZ LR24. I should delay the top
7 or 8 MS then? Thanks for your help.

The yamaha 215 drivers have been swapped for 1508-4 SPS BWX peaveys (4 Ohm) wired in series so I can have 2-215 8 ohm cabs running off a QSC bridged amp at 4 ohms 3100 watts. I'll be about 1000w under
what I would like to have but am in between the cont. and Prog rating.
Will have to save up for a bigger amp. Each 1508 is 500 c/1000 p
so I should have really have and amp that could do 4-5k bridged @ 4 Ohm

Top cabs will be 2-Peavey SP2 with 1800w bridged mono QSC PLX 1802
I have found that the peavey sub cabs (SP118) 8 ohm rated at 1000 P cannot handle hip hop sub freq's very well with 2 of them running off an RMX 2450 bridged.(1200 per cab) They blatt out a little but thats hip hop (much more sub material) than you get from a rock band.

So I hope I'll be okay with what power I have for now. It is my understanding that impedence of a sub driver is derived by lowest ohm rating in its freq range so a 30-300hz driver may be 4 ohms at 200hz
but can actually be as high as 20-30 ohms in the 60-80hz range. So in effect you are not really getting as much power as you think you are.

P.s. I got bad info I guess from training, or not enough!

Dra

If I may, I'd recommend a change in your sub wiring config.
The front speaker in a series run takes a lot of punishment becauese all the power run through it to get to the second speaker. If either speaker fails, you lose both of them. In 4 ohm bridge each of your 4 speakers gets 775w, but 2 off them are taking a beating. If you re-wire and run parallel at 2 ohms stereo, each speaker still gets 775w, but the power is now evenly distributed.

DRA

uhdinator

Thanks,

That makes more sense and the amp is getting the same load either way.

Gadget

I would further recommend moving the hi=pass up a bit. With the Peavey 118 (so sometimes you use the Yamaha's and sometimes the peavey's? or both at the same time?) the Blatting is the voice coil banging against the back plate (called the mechanical stops)...those really need a 45 hz BW 18 minimum...and maybe as high as 50 hz (especially outdoors... and with hip hop)A bit of a paradox here... the Yamaha speakers don't have a 2x15\" in the current lineup (and nothing in the \"discontinued speakers )I could find except the 'IS' series...and then the driver change would have been a BAD idea...If the driver replaced was in fact an Eminence Kapa 15 pro, then they are a fairly similar speaker (VAS 163.6 peavey, 167.7 Eminence) but they are still considered LF speakers and not sub speakers, and like the BW series I suspect don't make the best Subs, so extension to the 30 hz area is going to cause over excrusion...

Note: the Pro Rider series make excellent subs!

You have already addressed the power issue and that again, I would move the xover points..As I said, I'd start @ BW 18@ 45hz.

You might consider moving the HPF/LPF of the tops/subs xover up a bit for power reasons as well...
Gadget

uhdinator

The sp118 are installed in a club that I helped trouble shoot their system.
They do not have a DR. Maybe checking that the RMX 50hz filter is on is all I can do for them. (or tell them to get a DR)

The Yamaha cabs are sw215 4 ohm that were avail in the early 90's. Good subs but only 400w P each. I needed more power and the Peavey low rider drivers need way more power than I need. I know the 1508 is not technically a sub but its in the power range I need. The yammies original drivers are 40-2k range and the 1508's are 40-500k. (yamaha used JAY60070 15 in drivers).

The numbers I stated are for my setup with the BW1508 loaded sw215 cabs and SP2 tops. So you think 45bw18 and 110 LR24 ?
sorry I threw you a curve by mentioning the sp118.

Gadget

With your power situation I would, yes, especially with a swap out speaker in a box not designed for it. Not familiar with that driver, it doesn't cross in my speaker identification guide with any known speaker. So, chances are pretty good it's not matched to that cabinet very well...so ya... 45 hz BW 18..you understand why we spec the BW 18 right? It's because the steep slope falls off quickly and helps prevent over excrusion events...

So maybe I'm still a bit confused here, do YOU have the SP-2's? or are they with the SP118's? or do both systems have the SP-2's? and is YOUR system the one that has 900 watts going to each top? (if you can find a 100 watt stereo amp in your collection bi-amping those really free's them up) you may want to move that crossover point even higher... to even as much as 120 hz. What vintage SP-2?

As for the delay in the RMF section there is a way to determine the proper delay, but again with the DRPA it might be academic... but you could just sweep the delay till things tighten up a bit.

Those are the new generation Black widows I see. I haven't had one to test yet.. what is your impression of them? I put the Lo Riders in a OAP dual 18 \" cabinet with the same dimensions as the QW boxes by peavey and man do they sound good... I have gone on record as saying that the
new SP218 subs with the lo riders may be the best bang for the buck out there in front loaded subs...
G

uhdinator

The SP2's I have are the ones with the carpeted baltic cabs w/plastic port trim on the bottom corners and the red logo on the bottom of the grey grill. Not the latest new redesign with the grill that covers the horn and the driver and the new hammertex coated cab. Looks like spec are same on both.

My system is these and the 215 cabs that I am loading the 1508's in tonight. 1800w briged QSC PLX1802. (900w per SP2)
and the pair of 215 (2 ohm cabs with 1508-4) PLX3102 stereo 1550w ea

What effect will too small or too large of volume of the cab have on
performance of a speaker? The 215 has 2- 4in ports.
From my approx calc I think the cab is around 4.6 cu ft internal volume.

Freq/SPL spec looks like the peak area is 50-100Hz 97.5 db depending on
the volume. range is 40-2k (same range as yamaha orig drivers)

Specs says usable range is 35-2k. Though I see the SPL in the
40-50hz range is lower with a smaller volume. and the resonant freq
goes up with a smaller voume as well. (depending on port diameter and length too)

Gadget

Hey you got a name or would you prefer we call you by your username.. I'm Gary, but the Gadget is just the name I choose umteen thousand years ago and in another life, but the handle (if you will) stuck...Perhaps real names would be better here but we have assumed a certain informality, and an easy familiarity and lack of decorum between those that post regularly...You are welcome to join in as well.

Now, I have never kept up with the SP'2's and I have actually got a pair I \"built\" using peavey parts, but with my own specs ... cab wise, and they rock like crazy! I have however replaced the BW's with a JBL clone speaker that allows me to run fullrange and REALLY cranks with a bi-amp hi-power setup. I use them outdoors, in the winter primarily for ski hill functions that include snow board competitions where hip hop to heavy metal music is the norm...

I don't think I really get this:
My system is these and the 215 cabs that I am loading the 1508's in tonight. 1800w briged QSC PLX1802. (900w per SP2)
and the pair of 215 (2 ohm cabs with 1508-4) PLX3102 stereo 1550w ea
... unless you mean 2 of the SP-2's and 4? of the 215 subs?

And I'm also confused about this:
What effect will too small or too large of volume of the cab have on
performance of a speaker? The 215 has 2- 4in ports.
From my approx calc I think the cab is around 4.6 cu ft internal volume.
since I have never seen the new drivers I can't answer the question.. what are you asking? Are you asking if you use too little power what will happen? If so, they will not perform up to that ability, but if over powered they will have the clacking sound of the sp118's as the voice coil hits the back plate, or will distort and just sound bad ... and if you let that persist they will cook the voice coils and get scratchy or cease to make sound all together, or erupt in a spectacular ball of flame and if there wasn't a grill, would puke the flaming voice coil out onto the dance floor... either way, if you listen to the speakers and DO NOT have distortion, and never see a clip light except occasionally, you are probably safe...

The speaker itself may have a higher or lower resonant frequency, but the box design sets the hpf... The thing I've been trying to impress on you is that it's the BOX DESIGN that helps control the excrusion of the woofer, and if the box and the driver don't mesh properly, the driver can over excrude, and that will let the driver mash up against the mechanical stops... In a properly designed cabinet, a properly designed driver/box will have the effect of damping the cones excrusion @ the designed power and LF cutoff. So. when set up and designed properly, with the max power the driver can handle( usually 2-4 times the peak power handling of the individual driver.. that is to say if the driver is rated @ 400watts RMS 800 watts \"program\" that an amp capable of 1600 watts- 3200 watts (and this is an instantaneous ..peak.. power NOT continuous power )peak, is not unreasonable...NOTE that if you read the recent amp power redux we just did you will see that its the AVERAGE power you apply that will KILL a voice coil, that is to say that if the amp is approaching twice it's output capability, average, it WILL heat the voice coils to dangerous... even fatal levels.

Have you seen the links I provided in the RMBPosting section? In them is the PRO sound web \"study hall\" where al things pro audio are discussed...

Gadget

Gadget

:?:
is there something different here?
G

Fanman20

Greatings all

I was doing an outdoor gig on a cold winters night and after the event I was sitting on one of my Bose 502 sub's, (only one use for them, they make good steps as well, and nesting boxes for birds..........) when I felt the heat coming out of it.
With the 502's you can place your hand inside and touch the speakers magnet.
To my suprise I could not touch it as it was \"red hot\"
well too hot to touch.

So I supose speakers can be heaters as well. If you can stand the noise.


:shock: 8)

Fanman20 (Mark)

uhdinator

I'm using 2-215 cabs and 2-SP2 cabs.

Peavey spec that came with the 1508-4 says
small vented box 3 cu Ft with 4\" x 6 7/8\" port Vb box tuning freq 45hz

Since I am using 2 drivers and the 215 box is 4.6 cu ft and has
2- 4\"x 6 7/8\" ports I am guessing my volume is less than it could be and
will limit excursion. Internal approx dimentions 31.5\"h x 17.5w x 15\"D

I see on the spec sheet that a sealed box gives a freq of 87hz for the 1508 and presume that is because a sealed box would limit excursion
even more and in effect raise the resonant freq?

If these cabs don't sound okay I will just have to get into buidling a better
cab.

THanks..............Steve