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Amp for running 6x Oberton XB1500
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Power=V^2/R

so for a 1500w driver with 5.3 ohms RE  sqrt (1500x5.3) will give you the RMS voltage the driver was tested at.  
James Secker          facebook.com/soundgearuk
James@soundgear.co.uk               www.soundgear.co.uk
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My other question is this: while the original setup in qeustion was obertons, having read this it is making me question the limiting settings of the other components in my rig. I have two ES18s with PD186s in them running from a Proline and using the funktion one limiter calculator (http://www.funktion-one.com/settings/) it told me to set my DP limiter to -2dbu. However, I suspect that is the value needed to reach full RMS power so was wondering how I would calculate it to conform with what you guys have said about powering drivers in horns?
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For peak limiters i tend to limit at about 1-2dB over the AES rating for bass and 3-4dB for mid high.
James Secker          facebook.com/soundgearuk
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Am really sorry if I'm picking your brains too much haha but if you don't mind I have another question! Is a peak limiter going to be enough to protect my drivers ? And if the limit is set above the AES rating then how exactly is that going to stop it killing drivers as you stated that even half of the AES rating is enough to kill them?
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in rough terms, peak limiters will protect your drivers from physical damage ( pole plating, hitting X-mech etc), RMS limiters will protect from thermal damage.

using peak limiters alone will not stop you during voice coils, and if used poorly can actually significantly increase the long term average power sent to your drivers.

without top of the range limiting, you have to think old skool - good driver / amplifier matching and listening to your rig when it is running - if it sounds happy it usually is...
“The fact is this is about identifying what we do best and finding more ways of doing less of it better”
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If you use a peak limiter set at just above the AES rating then you will still be safe as long as your music crest factor is reasonably high, which is normally is,  having an RMS limiter as well ensures that if you do have low crest factor signal then you will also be safe in that situation, imo this extra level of safety can allow you to use a bigger amp and squeeze a little more out of your speaker safely.  

Peak limiters are fine though,  i have run systems for many years on peak limiters, shortest attack and longest release for maximum and very very rarely blown anything, i tended to set the peak limiters lower though, with an RMS limiter in place so you are thermally safe you can open up the peak limiter to just deal with over excursion or clip prevention.
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Points: 298 		Post Options Post Options   Thanks (0) Thanks(0)   Quote junoprobelaunch Quote  Post ReplyReply Direct Link To This Post Posted: 11 October 2018 at 10:34pm
Thank you for that mate, had me worried that I would have to buy a new DSP with an RMS limiter so i didn't risk my equiptment haha. Think after all of this I'm gonna grab myself an FFA 10K, hang two Obertons per channel to start with and then splash out on an RMS limiter and then run 6 of it. 
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Originally posted by csg csg wrote:

in rough terms, peak limiters will protect your drivers from physical damage ( pole plating, hitting X-mech etc), RMS limiters will protect from thermal damage.

using peak limiters alone will not stop you during voice coils, and if used poorly can actually significantly increase the long term average power sent to your drivers.

without top of the range limiting, you have to think old skool - good driver / amplifier matching and listening to your rig when it is running - if it sounds happy it usually is...


And a good manufacturer does testing to set peak, RMS and also thermal, Xmax and power limiters to handle all situations, ideally with frequency shaped filtering too so that it can vary with signal content like a real speaker does.

This is currently an area I’m doing a lot of work on Timebomb - been a long time since we met, perhaps we should have coffee soon?
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As per the other Chris's comment, in the absence of very expensive power measurement and/or processing, the best way to avoid blowing your system up is to use your eyes, ears and common sense.

I use clip limiters set slightly above the maximum output of the amplifier so it can achieve maximum Voltage swing but stops it the signal turning into a complete square wave!  However ultimately the limiter is me.  If I'm just tickling the limit lights occasionally then I take that to be the system running at maximum level. If I start seeing more than a brief flash every few seconds then it's time to turn it down.  The only difference is if I do leave a system unattended then I'll normally wind the limiters back a few dB to a more conservative level and probably increase the release time too.

As for the question of how much headroom, well it depends of course!  Mainly on the style of music.  I do a lot of live work and for that I like lots of headroom because of the high crest factor, especially on mids and highs.
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No need for 3x pages on this topic.

Just get K20, or PL380, or 2x Void Inf8MK2.

I've heard FFA10s, E90s, Crown ITECH 8s.

IMHO, None of them provide the lows AND SPL, Like the above.

All done.
Global Depopulation - Alive and Killing.
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Originally posted by toastyghost toastyghost wrote:

Originally posted by csg csg wrote:

in rough terms, peak limiters will protect your drivers from physical damage ( pole plating, hitting X-mech etc), RMS limiters will protect from thermal damage.

using peak limiters alone will not stop you during voice coils, and if used poorly can actually significantly increase the long term average power sent to your drivers.

without top of the range limiting, you have to think old skool - good driver / amplifier matching and listening to your rig when it is running - if it sounds happy it usually is...


And a good manufacturer does testing to set peak, RMS and also thermal, Xmax and power limiters to handle all situations, ideally with frequency shaped filtering too so that it can vary with signal content like a real speaker does.

This is currently an area I’m doing a lot of work on Timebomb - been a long time since we met, perhaps we should have coffee soon?

Yeah bob in if your up this way, im normally about,  i will do some more refined presets for my systems when the new processors are ready but its looking like the new year now... 
James Secker          facebook.com/soundgearuk
James@soundgear.co.uk               www.soundgear.co.uk
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very interessting - after reading this thread i guess running 4 xb1500 in scoops with inf8v2 (4ohm= +-2500w) is quite a perfect match. I always thought it is not enough for handling 2 1500w drivers per channel in theory ,despite the fact that they sound like earthquake allready with +-5 ampere each channel (like +-500w per driver) - now I can sleep better. ClapLOL btw never burnt a driver with that setup in 4 years only using shit behringer dsp limiter which never kicks in on sub anyway


Edited by Miles - 12 October 2018 at 1:42pm
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