BillFitzmaurice.info

DJPhatman wrote:Using your Mackies at full range, and using your T39s below say 100Hz, is wrong, wrong, wrong! Having multiple sources of the same frequencies, in my example everything below 100Hz, will cause lots of cancellation nodes. Basically, you will be doing more "harm" to the sound than good. Run from the mixer into the crossover. Split the signal 100Hz and up to the Mackies, 100Hz and down to the T39s amp. Run both T39 on the same channel of the amp. Use the highest slope of crossover you have, 24dB/oct or 48dB/oct. Linkwitz/Riley is the preferred crossover type, and 48dB/octave is the preferred slope.

I don't see why running them on the one channel is a good idea otherwise you got almost everything you need right there.

Billy beat me to it but yeah, you can't do it without a voltmeter. Relying on the clip lights of the amp is dodgy. Especially with no limiter. The amp is certainly powerful enough to blow your speakers if you let it.

If you trust the amp to put out the rated power at clipping and then wind on the limiting so a full noise sine signal out of your crossover won't light up the clip it's better than no limiting. It won't be near as loud as it could be.

Far be it for me to be educating anyone on how to set any limiter. However, I'm getting a little more familiar with the analog limiter that's coming my way soon and nobody else wants to stick their oar in so here's 5c worth: Presumably the same paramters are there in the dcx. Select hard knee, max (infinity) ratio (aka slope), fast attack and release, ie small numbers of milliseconds.

BTW. You can play with the limiter to your hearts content with the amp set to full power and no speakers plugged in. Get a voltmeter, RTFM, and then make some noise. You should be overrunning your tops easily and have to turn down the subs.

Gregory East wrote:I don't see why running them on the one channel is a good idea otherwise you got almost everything you need right there.

Running on 1 channel will be a 5 Ohm nominal load to the amp. This will give decently close to specified power for the EP-2500 @ 4 Ohm. Running one on each channel would be a 10 Ohm nominal load at each channel, and most likely will not provide enough power to push 3012LF to full power.

And, I said it is not a good idea to run the Mackies at the same frequencies as the T39s, as you will get nulls and voids of bass due to frequency cancellations. The the subs do what they are designed to do, 45Hz to 100-120Hz. Play around with the high pass frequency to the Mackies until they sound the best to your ears. 100 Hz is a good starting point. I have used mine as high as 125Hz, with no issues, and liked it. But, I ride the faders, EQ and crossover frequency for each song playing. What sounds good for one song, might not sound so good on the next song.

http://www.musiciansbuy.com/BEHRINGER_EP2500_AMP.html says 450W @ 8 Ohm, 650w @ 4 ohm

ok...i have my ep2500 amp set up this way b/c this is what i was told:

I have from my crossover output 1 (1 connection into input 1 of the ep2500 amp) input 2 of my ep2500 is not being used...

then from output 1 of my ep2500 i have a speakon cable going into one of my t39s and from output 2 of my ep2500 i have speakon cable going into the other T39...is this not correct??? is this giving me the full potential of my t39 (loaded with 3012lfs) or not???

and as of now i have no limiter settins its on (0) b/c i have no volt meter...and im really not understanding still how to set the limiter...i was just trying to play it safe but its making no sense...and i take it there is nothing i can do to protect myself tonite in short notice time with the limiter settings...

also...i was told to use the butterworth setting?? so the LR is better???

Order this. Do it yesterday.
http://www.partsexpress.com/pe/showdetl ... er=500-342

If you're going to use sound gear you have to know how it works.

<smacks head on ground for not getting Leland to source me one of those along with all my bits>
The limiter needs a point of reference. The amp clip lights aren't to be recommended but if that's all you've got......and you've got a computer that you can make a test tone CD with......cough, you didn't get that from me, cough.

You need to RTFM on the amp as well. You don't want it to be in bridge mode as it seems to gain a LOT more welly.

Did you get sound coming out of both subs last time out? If so then I guess you got it switched ok.

All in all it's probably safer not shooting for full output of the subs. Both on the one channel nets 650W, cough, cough, before clipping. Very dangerous ground, don't complain if your milage varies and they fry.

A voltmeter can be had for 30 bucks that will give you a rough and ready RMS reading. The signal is pure A/C sine wave so there's no excuse for a cheap meter to be very different from an expensive one that computes RMS from any A/c source.

I'm using both channel outputs for my t39s...in stereo mode...i did use them already for one event...did fine...just needs tweaking and limiter set...

do most people use l/r48 or butterworth 24?? just seeing what people tend to like

and once again im confused...people are telling me different things...should i use the 35 hz high pass or the 45 hz setting ?? i play mainly mainstream and hip/hop club type of music...whats the real difference and the preference of most?

You can play 35Hz if you really have to but there's a very much lower power capacity. I forget what it is. Very unwise to try that on without limiting.

For your hiphop that gets played on the radio your 45Hz should be fine and dandy. The Mackies hardly make a dent down at 45Hz.

thanks man appreciate the feedback ill go with 45 hz and 100 hz...and i guess l/r 48 for both?

hollywd901 wrote:thanks man appreciate the feedback ill go with 45 hz and 100 hz...and i guess l/r 48 for both?

Yes, use Linkwitz/Riley 48dB/octave. This provides a smoother transition at the crossover point.

Invest in a good quality voltmeter, and a good quality SPL meter, or the reference mic for the DCX for SPL readings.

Ok going to purchase voltmeter today...to finally set the limiter on my dcx2496 before the weekend...can someone tell me what to look for in a voltmeter...where do i get this sine wave?? and how long should it be?? and finally when i set up my equipment in the morning do i need the t39s attached to do all this or my mackies attached??? ive read the setting the limiter thread but its a lot of confusing jargon that is making this hard to understand...anyone tell me in laymans terms how to do this exactly?? thank you!!

Sine wave comes from your PC running "Audacity", free software.

Solid state amp so no speakers attached, you may have to open the amp case to get alligator clips on, or else make up a speakon with bare wire. (Unlikely you have phono outs to clip onto the end of a jack cable and blowed if I'm loooking up your amp again to see)

Best bet on voltmeter is to borrow one off an electrician. In your situation I might invest in a cheap A/C meter and go to an appliance repairman with a real deal RMS Fluke. Spend a half hour calibrating the PC/mixer/processor/amp with both meters. That way if you expand the system you'll know if your cheapo is accurate enough. Heaps cheaper than buying a RMS one yourself.

ok so sine wave?? i do have audacity what is a sine wave and how do i get it...is this similar to the 30hz tone i used when building my t39s??

I have noone to borrow a voltmeter from...was going to walmart or true value to find a cheap one...any suggestions anyone??

and I use an ep2500 amp by behringer...Im totally lost on how to even start this process of setting my limiter...ive read the manual and the articles...i need simple terms from anyone please...

and am i setting this for the t39s and the mackies(since they are self powered and have contained amps)
thank you!

afaik Audacity spits a sine wave when you ask it to.

True RMS means it averages any alternating +/- voltage into a reliable average voltage.

With a cheapo you are relying on the fact that you already fed a true RMS signal ( pure sine wave start with!) into the mixer. So long as it's an A/C meter Bob's your hairy arsed Aunty.

EDIT, yep opened Audacity hit "generate" and wadayaknow? sine wave option pops up top of the table.