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[Timmahh]

ok heres the situation.
outdoors festival in a tent. 100x60. large stage at one end.
running 4 Lab Subs v3. powered with EWIs HS3600s 1800w@2ohms/side/cab.
running 4 Viking Audio X215 tops with EWI PS2000s 1000w@4ohms/side/cab (dual 15s) and EWI ES1000 350w@8 ohm/side/2in driver.
managed with DBX 260.  
Any thing i should be aware of besides the normal delay times?

also have a question on burn in times and techniques.
what have you guys done as far as burning in the drivers and getting your Labs ready to work?

I ve been through the board as much as possible and these were a few questions i still was wondering about.

thanx in advance.

[Too Tall (Curtis H. List)]

Timmahh wrote on Sat, 26 March 2005 22:25

also have a question on burn in times and techniques. what have you guys done as far as burning in the drivers and getting your Labs ready to work? I ve been through the board as much as possible and these were a few questions i still was wondering about. thanx in advance.

The idea that you need to or can "burn in" a driver is disputed. That said the only time I can see where it might make a difference is if you were measuring the T/S of a new driver and then based a design on those numbers. In your case the design is done so you not only don't care, there is nothing you can do about it.

   Personally when I get a new driver I run a 10Hz sine wave a ways below Xmax through the raw driver for a few hours and check to see if the Fs has gone down some. I also catch any "infant failures" right out of the box.

   In some cases the Fs moves down a couple of dB. Sometimes I believe I get better bass out of a system after I have run it for a couple of months, but when I measure there is no change.

Anyway, as I said, in this case it does not matter. The driver is not like a car engine that needs to be "broken in" before you can push it to its limit. Cone speakers are large tolerance parts when you look how big the gap is compared to the voice coil.

[Timmahh]

well we hooked up the four labs we have done tonight for about 20 minutes and just ran some stuff thru them with the dbx 260 vaguely set up for the sub channel. high passes at 40hz, and low passes at 99hz.  set the LR at 24 db slope at 40 and 99 respectively.  Coupled all 4 together shooting out the garage, and ran them 1 cab / 1 side of an amp.  EWI HS 3600 giving 1800w/side@2ohms, and only ran material at a moderate level ( as it was midnight when we did it, didnt want to push the envilope to much ).  all i can say is WOW, i wish these were available 6 yrs ago. will run some more test tomorrow for a few, and put it into play friday and saturday. will report back more l8r.

[TonyPybus]

Let us know how they perform. I've been eyeing that version for awhile now and hoping with the changes they'll go up to 120hz.

[Brad Litz]

I'm using my v3.0 LABsubs with td-2's crossed over at 120Hz.
Plenty of headroom here.

[Timmahh]

well.  after last night all i can say is NICE...

heres the layout.
Large tent, 150x80, the stage (err flat bed trailer) is at one of the 80 foot sides about 18 feet from tent to stagefront.   we ground stacked 2 Lab V3s per side with 2 Viking X215 cabs per side for tops ( X215 has 2 15 drivers and 2 in horn in ea.) just in front of the stage area at each corner.  With the 260, we crossed over near 90, hpf at 40 with about 9.8 seconds of delay to the tops.  the stage was set left of center in the tent, so the left stack was 2 feet from the edge of tent and the right stack was just right of center in the tent.

you could stand pretty much anywhere from one stack to the other the coverage and presance were nice. the lows were full and punchy. there did seem to be some beaming going on, as when you would position yourself at center between the stacks it was very full and rich sounding but did taper off toward the edges.

when i went to the far back right side of the tent, pretty much opposited corner from stage/FOH layout, the lows were still there but just not as much.  considering it was 3/4s into the night and there were about 350-400 people maybe, and you could still make out the bass in a defineing mannor, i was pleased
i am going to do a quick 260 change and adjust the crossover point up to 110 to 140 area, just to see how the Labs do considering they are capible, and do some comparrision, that is if time allows us to do so, and will give a report as to any differances.  

I have Smaart on my laptop, but not sure if my mic input is stereo or not, dont think it is but. so my question here is what are you peeps useing to go from xlr for the RTA mic, to your laptops.  i ve looked at the m audio and the VX pcmcia card, but was wondering if there is anything else out there i should consider using befor making my final purchase. the Digigram VX card looks pretty nice.  i also see creative labs have made a pcmcia soundblaster card with a spdif and rca connections, anyone use this, it s price range is good at 130.00 or 80 for the usb breakout style box with a few extra connections.

Anyways thats a bit of the deal for the first time out, i m very happy with the results considering it would of taken 8 - 12 dual 18 cabs to get even close to the coverage we had, but would really like to get some good smaart readouts with a screenie or 2 to post. talk more l8r.

[Ivan Beaver]

I am using the USBPRE from sound devices.  This in on the upper end price wise, but is very robust and I have not had any problems.

Ivan Beaver

[Michael_Elliston¶]

Those vikings use all JBL components  
Are you going to ever let the HPF drop down to ~32hz someday?Risky?

[Timmahh]

well IF you buy them from the Viking Factory loaded, then they are loaded with JBL 2226Hs on the 15s and JBL 2445Js 2in compressions.
Mine are loaded with different drivers.  2 pair area loaded with JBL 2225Hs, and 2 other 2 pair are loaded with the Zomax 2225H 15s. all the 2 inch drivers in my cabs are the Zomax 2445Hs.

imo. the Zomax 2in compression drivers are a bit smoother and not quite as Brashy sounding as the JBLs. They are rated 100/150 peak.  As far as the 15s, imo, the Zomax 2225s ( rated 500/1000) seem to carry a little more mid range honkyness, but with a lil eqing, they sound very nice.  and im sure we are all familiar with the JBL 2225s line of drivers (of course rated at 400/800).

everything sounded very nice, didnt notice any major problems (we ran the jbs on one side the Zomax on the other) with phaseing or any cancellations, but we didnt get a chance to get the set up smaarted this time either, with the exception of the power alley we had going on with the Labs. but giving the way the tent was set up n how we had to set up do to the configuration, i would of been surprised if we DIDNT get some power ally effects goin on with the Labs.  

is all for now.

[Timmahh]

actually we discussed setting the labs in a center cluster to get all 4 coupled together  so we could set the hpf at 35, but did not have the xtra time to refigure it all out. but im sure it is something we ll end up doing in the future.  our next outing is in 2 weeks, where we ll only be using one stack per side, and maybe we ll try to center cluster 2 labs, depends on time and the set up of this show, another large tent show.
when we have a chance to use all 4 Labs again, which should be soon, maybe 3 or 4 weeks, i would like to give this a try, i feel it could give us better coverage and ofcourse better coupleing with 4 LABs centered, which should allow us to get down to 35 to 37 at least without much risk?.?.  i guess time and a possible trip to the reconer will tell.

p.s.  i think im going to throw my hat into the reconeing business.  although the reconer i use is priced very humbly, money is money, and its not being tossed my way everyday becuase i am me..heh.

[Ivan Beaver]

All sub will exhibt a "power alley" effect.  This is due to the omni direction of those freq and the combining effect going on.  Try this to tame it down a bit.  Turn down 1 side 3-6db.  Only the people directly in front of one side may notice anything.  This will tame it quite a bit and give a much smoother lowend response overall the listening area.

Ivan Beaver

[Too Tall (Curtis H. List)]

Timmahh wrote on Sat, 02 April 2005 12:03

snip- I have Smaart on my laptop, but not sure if my mic input is stereo or not, dont think it is but. so my question here is what are you peeps useing to go from xlr for the RTA mic, to your laptops.  i ve looked at the m audio and the VX pcmcia card, but was wondering if there is anything else out there i should consider using befor making my final purchase. the Digigram VX card looks pretty nice.  i also see creative labs have made a pcmcia soundblaster card with a spdif and rca connections, anyone use this, it s price range is good at 130.00 or 80 for the usb breakout style box with a few extra connections. Snip-

Your on board sound chip needs to pass several tests.
First you need a stereo input.
If your laptop only has a "mic" input you need that to be true stereo. If it also has a "line" input you can ignore the mic input. It is unlikely you will use a mic that would work properly into it and many laptop mic preamps are garbage.

To tests for true stereo for either the mic or line input all you have to do is record a wav file and make sure you are only feeding one channel. Then play it back and see if the sound shows up on one or both channels or only the one you had the microphone hooked up to. Do the test for all inputs.

Next you need to be able to shut off any monitor signal at the output since this will cause a feedback loop.

To do this feed a signal into the input and record it to a wav file and while you are recording listen to the output. There should be nothing there. If there is you need to go into the windows mixer and choose "playback" under properties, then look for something that can shut off the monitor signal to the output. The wav output still has to stay on and turned up. If there is a master volume out that has to stay turned up. Everything else needs to be muted or turned down all the way.

Is your on board sound chip good enough for what you are doing?
If you bring it down to Bridgeport I can hook up a ESI U24 usb soundcard and compare it to the on board chip. I did that with the chip on my Thinkpad and it was very close to both my U24 and my Echo Gina pro card in my desktop tower. If drops off on the low end and I believe it has little more noise overall. For EQing a PA I would not hesitate to use it.

That said you can buy usb sound cards for cheap. I stay with usb soundcards because I don't like to tie up the pcmcia input. You can stack lots of usb on a hub.

In any case odds are you will have to use an external because the chip will not be Stereo full duplex.

You need to look at the mic you will buy, the mic preamp it needs and the external (or internal if you use it) soundcard all at the same time.

If you only spend $30.00 on a Behringer ECM8000 measurement mic it is foolish to spend the money for an expensive USBpre soundcard. You could buy a cheap USB card (if you need it) and a stand alone mic preamp for just over $100.

I'm including a zip file showing the comparison test I did comparing my Echo Gina 2x8 PCI sound card with the crystal fusion chip in my laptop and a iMIC that works with both Macintosh and PC (It is VERY cheap).

[John Roberts {JR}]

Ivan Beaver wrote on Sun, 10 April 2005 09:36

All sub will exhibt a "power alley" effect.  This is due to the omni direction of those freq and the combining effect going on.  Try this to tame it down a bit.  Turn down 1 side 3-6db.  Only the people directly in front of one side may notice anything.  This will tame it quite a bit and give a much smoother lowend response overall the listening area. Ivan Beaver

I don't have specific experience in this so I will phrase this as a question... Wouldn't that just skew "where" the power alley occurs? Unless you turn the second sub down so far it is not a significant sound source it seems it will have the capability to interfere.

What do you think about putting multiple subs together so their summation can be constructive?

JR

[Ivan Beaver]

Not so that I have noticed-the wave lengths are so large. I have gotten nothing but positive results.  By the time you get a small distance away, it starts making larger and larger changes in distance to notice anything. Think of it as using a single sub on 1 side to try to fill the room.  It will because it is generally omni.  However on the far side the level will be a little lower, due to the distance away from the "main" sub.  The one on the other side then acts as "fill" to overcome this loss of level.  Since the main sub is generating a decent level the extra sub just needs a lower level.  The problem does not go away, BUT is greatly minimized to the point of it-most of the time- not being a noticable problem.

In regards to the coupling.  That is always the best idea-espically for cabinets like the labs that really need it to achieve max low freq response.  The problem then begins where to put it.  If it is in the center of the stage, the seats in the middle suffer from an unbalancing of the mains/sub level ratio.  In the install world I like (if possible) to fly the subs.  This takes away the distance/level issue-however you no longer have the coupling to the floor to help.  It is all a series of compromises.  In the install world, even coverage is more important than punch factor.  Just make sure you have enough subs to do the job.

Ivan Beaver

[Timmahh]

Curtis, it only has a mic input, and according to the manufacturer it is only mono.  so it looks like pcmcia or usb. i ve been looking into the preusb from MAudio, as well as the Digigram VX440. both nice units. I see that Creative has also made a pcmcia soundblaster card but has no xlr availabilities, so i ll prolly stick with the preUSB or the Digigram card.

As far as mic, i ll be useing the DBX RTA mic. i bought one when i picked up the 260. so i ll want to stay near the top end for audio interface.

it has a realtek onboard so it is only so so.

I know Ken and I have been wanting to bring down the 4 v3s we have and stack them next to Al's and see what if any differances there really is. but now its getting to be the busy season, so hopefully we can itch out a few hrs one day to compare.
talk l8r.

[Too Tall (Curtis H. List)]

Timmahh wrote on Sun, 10 April 2005 16:39

Curtis, it only has a mic input, and according to the manufacturer it is only mono.  so it looks like pcmcia or usb. i ve been looking into the preusb from MAudio, as well as the Digigram VX440. both nice units. I see that Creative has also made a pcmcia soundblaster card but has no xlr availabilities, so i ll prolly stick with the preUSB or the Digigram card. As far as mic, i ll be useing the DBX RTA mic. i bought one when i picked up the 260. so i ll want to stay near the top end for audio interface. it has a realtek onboard so it is only so so. I know Ken and I have been wanting to bring down the 4 v3s we have and stack them next to Al's and see what if any differences there really is. but now its getting to be the busy season, so hopefully we can itch out a few hrs one day to compare. talk l8r.

The weather has been teasing us. I thought you might bring some of the top boxes too.

Just for the fun of it I looked for a suitable mic preamp on ebay. After about 5 minutes I found this-
M-Audio Audio Buddy Dual Mic Preamp W / Phantom Power

Item number: 7314426100

I bought a DBX 2-channel off ebay for about $75 to use with my laptop.
The DBX mic isn’t bad, but is most likely not a high end mic. It could be very close to the response of a B&K or Earthworks and STILL be the limiting factor in performance when comparing a USBpre to a less expensive external soundcard.

Take a look at the The M-Audio Transit

http://www.libinst.com/ESI_AUDIOTRAK%20CARDS.htm

With the audio buddy preamp and usb soundcard you have less then $200 invested that will do anything Smaart will ask of it while the USBpre costs THREE TIMES as much.

The big advantage for your purposes with the USBpre is that you have only one box to haul around instead of two. That and the fact that it is expensive gives it a high “toy factor”.


PS- Another reason I dislike PCMCIA cards is on some the cable harness attached to it stresses the card making a mechanical stress point for cable failure and torque on the card itself as opposed to a simple usb cable plugged in for a usb soundcard.