Setting Limiters

[Dave Non-Zero]

This is all very interesting, but you are distracting me from my drumming practise.

[osse]

What do you think about the behringer epx series? How long have you had it? Has it ever failed on you? Ive read about it and there is some bashing especially regarding power ratings not as high as stated.. maybe it wouldn't matter with the easy driven tuba designs, the 2000 is cheap and look tempting but its no use to buy something that could die on me any minute..

How is the sq?

[Dave Non-Zero]

I've had the epx4000 for over 6 months now, driving 4 t48s. It's Done at least 150 gigs (average 5 a week, mostly 4bands a night and at least 50% metal bands.)
ocassional clip lights every now and then... I know this thread is about limiting, but hey.
never skipped a beat. Been great for me. I would and will buy more.
Do wish it had a bit more power tho.

[osse]

I've had the epx4000 for over 6 months now, driving 4 t48s. It's Done at least 150 gigs (average 5 a week, mostly 4bands a night and at least 50% metal bands.)
ocassional clip lights every now and then... I know this thread is about limiting, but hey.
never skipped a beat. Been great for me. I would and will buy more.
Do wish it had a bit more power tho.

Great to hear! Actually I meant dongas epq series.. but great with epx review too!

[osse]

I've had the epx4000 for over 6 months now, driving 4 t48s. It's Done at least 150 gigs (average 5 a week, mostly 4bands a night and at least 50% metal bands.)
ocassional clip lights every now and then... I know this thread is about limiting, but hey.
never skipped a beat. Been great for me. I would and will buy more.
Do wish it had a bit more power tho.

Now I see the epx is new version, I thought we talked ep4000, need more power you say? It's got plenty according to specs.. which has history to not be valid

Do you think its a good match with 4x tuba30 3012lf?

[Dave Non-Zero]

It claims 900w per channel at 4ohms, which is about prefect for the 30xxLF series, but taking into account the higher impedence of the BFD I would rather have a bit more headroom to keep the amps coasting. I also use a yamahap7000 for another 4 t48s and it does well. 1200wpc at 4ohm. The 3015LF have proven to be pretty rugged at full power. (I've lost a couple over the last few years, but nothing disasterous)

the epx series has been claimed to be almost identical to the old ep series, but with claimed higher power (up from 750wpc at 4ohm) so I'm would take a figure between the 2. a great amp for the price tho.

[osse]

It claims 900w per channel at 4ohms, which is about prefect for the 30xxLF series, but taking into account the higher impedence of the BFD I would rather have a bit more headroom to keep the amps coasting. I also use a yamahap7000 for another 4 t48s and it does well. 1200wpc at 4ohm. The 3015LF have proven to be pretty rugged at full power. (I've lost a couple over the last few years, but nothing disasterous)

the epx series has been claimed to be almost identical to the old ep series, but with claimed higher power (up from 750wpc at 4ohm) so I'm would take a figure between the 2. a great amp for the price tho.

The epx4000? Seem to measure 1200 at 4 ohm according to specs, have you measured voltage in bass region? in that case, how much before clipping? With its weight and price it Seem good if it deliver the goods

[Dave Non-Zero]

Sorry I've just realised I have the EP4000 not the epx.

Anyway, the claimed 1200 wpc at 4ohm is peak power. Just like the EP4000 is rated at 1400 wpc at 4ohm. Look at the manual and you'll find the RMS power rating.

[Boyd]

I chose to run off a smaller amp....320 per side into 8 ohms instead of 500.

+1

Bill quotes the excursion limit for the 3012LF at 300W, hence the 50V limit. It's not nessesary to supply the 450W thermal rating.

It seens like oversized amps are causing gain structure issues when setting limiters for quite a few people. If you've got excessive amp gain you'll just have to turn it down again somewhere.

A little headroom is a good thing for the reliability of the amplifier. A lot is just a P.I.T.A.


I'm yet to buy a DCX, but having a quick look at the software, there are gain controls in the EQ / Dyn section for each input and output band.

After setting the limiters with Amps full up, I'd match my prefered max desk level to max input on the DCX, and adjust the gains in the EQ sections for desired limiter engagement at this input level, then double check the limited output voltage.

Now you can safely adjust the amp gains to suit the room, # people etc.


Personally I'd like to see more limiters with ratios of 'greater than infinity', by which I mean that as the input gain continues to increase beyond the limit (usually after a few Db's of infinity ratio limiting) the output actually DECREASES! Great for taming unruly DJ's, but there arn't many around that I know of. Formula Sound has one but it's insanely expensive.

[CoronaOperator]

Personally I'd like to see more limiters with ratios of 'greater than infinity', by which I mean that as the input gain continues to increase beyond the limit (usually after a few Db's of infinity ratio limiting) the output actually DECREASES! Great for taming unruly DJ's, but there arn't many around that I know of. Formula Sound has one but it's insanely expensive.

This might work on the DJ's. Maybe not the first couple dozen but eventually word will get around.

[Boyd]

LMAO!

Or maybe a switch that makes the DJ mixer top plate 240V live and ungrounded beyound 6db of limiting?

I'm an occasional DJ myself, but a sound tech first and foremost. I hate to think how hany times I've tried to explain to DJ's that quality is more important than quantity alone (turn down the distorting P.A. by a few Db's and enjoy the massive increase in quality). If you turn it down slowly enough no one will ever even notice it's slightly quieter.

I've left so many gigs because it was all volume and no quality. My ears hurt, and I value them more than the DJ's ego.

[Grant Bunter]

Hugo, please, I'm not trying to shoot your down.

Many people here who use Bills cabs as systems are running completely horn loaded systems, both subs and tops.
What's your experience with such systems?
Many of the same drivers, if used in direct radiator systems would (perhaps) respond differently.
However, unlike direct radiator systems, you don't get warning signs, such as distortion.
You just get silence when horn loaded designs are run past their displacement limits.

You may have sufficient experience to prevent blown drivers from occuring without limiters, but, especially for subs of Bill's designs, limiting is a mandatory thing, because there is never anything to stop some idiot doing something to your system you wouldn't.

And we are not talking limiting as in compressor/limiter, but "brick wall" limiting to prevent blown drivers from (sometimes) modest amp outputs....

[Keryn O'Shea]

An amp has a input preamp that works in unison with the output power and you will get the most distorsion free output with it all the way up.

Excellent, along with using a berry xenyx802 between the mixer, immediate improvement to my gear, thanks man! (yes I'm a Dj, well..was)

[alexk]

This thread has been hugely useful - thank you everyone.

I'm having trouble, though, figuring out what voltage limit to use for drivers that are within spec but aren't specifically listed in the plans. My search-fu is failing me as well.

Is there a formula I can plug enclosure and thiele-small parameters into to determine voltage limits?

Thanks!

[Bruce Weldy]

This thread has been hugely useful - thank you everyone.

I'm having trouble, though, figuring out what voltage limit to use for drivers that are within spec but aren't specifically listed in the plans. My search-fu is failing me as well.

Is there a formula I can plug enclosure and thiele-small parameters into to determine voltage limits?

Thanks!

Are talking about subs or tops?

For tops, calculate the voltage for 50% of the thermal power rating of the speaker (RMS not peak).

For subs, find the listed speaker with the closest xMax to yours....use that voltage.