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Author Topic: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass  (Read 13830 times)

Mac Kerr

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #10 on: July 06, 2014, 02:40:17 pm »

I do have some experience with the DJ's that play for this gig.  The majority have been educated about the pitfalls of compression and keep their files at 320kbs or high quality variable.  I know one DJ specifically that has used the system, experienced the problem, and keeps their music files at 320.

Johannes was not talking about data compression, he was talking about dynamic range compression. Data compression effects the quality of the signal, dynamic range compression raises the average power required.

Mac
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shawn swanson

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #11 on: July 06, 2014, 02:41:44 pm »

A Honda EU6500 is a great genny with lots of power, so the problem is likely in your power distro. The 200 ft run of 6 ga is probably OK. But if you're using 12-gauge to link from speaker to speaker in a daisy chain fashion, then the first run of 12 ga is being forced to carry the amperage of all speakers downstream. How exactly are you splitting the 6 ga / 240-volt end into 120-volt feeds?

Since you're doing everything else correctly, I would suggest you get a real power distro on the end of your 200 ft of 6 gauge run. Called a spider box, it splits your 6 gauge / 240-volt feed into multiple 20-amp / 120-volt outputs, each with their own circuit breaker and GFCI. You'll want to do single "home runs" of 12-gauge wire from each powered speaker back to the spider box distro. That should minimize voltage drop under heavy bass conditions. 

giving each speaker it's own cord off the spider box makes perfect sense Mike, and I will see that gets done (though it won't be a Whirlwind).  I'm still wondering about the single neutral caring the whole load though.  I know that on a 240v circuit a balanced load would send return current down the opposite leg.  With the 240v circuit split into (2) 120v circuits wouldn't the neutral have to carry the whole load back?  Since this whole system runs on a genny and does not get connected to an earth ground could I use the green conductor as a second neutral?  Or does the ground still provide protection against shock on a genny without a grounding rod?  Or at least I would bet they are not grounding the genny...
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shawn swanson

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #12 on: July 06, 2014, 02:45:59 pm »

Assuming the distro is wired correctly, the neutral is carrying the DIFFERENCE between the load on each hot wire.  Example,  12 amps on one and 10 amps on the other, the neutral will carry 2 amps.  I agree that  the 200 ft #6 is not the problem.  A plug in volt meter would be useful to trouble shoot this.

Missed this earlier - Thanks Frank.  Would it be too much to ask how to wire the distro correctly?  I would just pigtail the nuetrals from each 120 circuit together at the #6 coming from the genny.  Would it be done differently?
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Johannes Halvorsen

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #13 on: July 06, 2014, 02:46:34 pm »

I do have some experience with the DJ's that play for this gig.  The majority have been educated about the pitfalls of compression and keep their files at 320kbs or high quality variable.  I know one DJ specifically that has used the system, experienced the problem, and keeps their music files at 320.

As for the Monster Cable box - I would say your probably right Dick.  I think some M.C. gear is pretty good, but all of it has more marketing than substance in it. 

I looked up the Whirlwind distro gear - Sweet!  I would love to play with that stuff but it looks like it's beyond the budget of this group.  This set up is used at Burning Man, a non-commercial festival.  They don't make any money with it, they just do it for fun.  I think I'm going to grab a pile of good quality hardware and rebuild the cord and distribution as I am going to the festival this year and will get my hands on the rig then.
"Compression" in this context has nothing to do with mp3 or kb/s. It's dynamic compression. In short: The difference between the loudest and the quietest part of the music is reduced to make the track sound louder. Roughly speaking it's the same thing that happens when you drive a powered speaker so hard that the limiter light starts to flash, but of course the effect of the protective limiter is much more audible.

Many users of this forum are so sawy they don't remember the time in their life when they didn't know what a compressor was. But some of us still haven't learned all the magic of audio yet. ;)

I'm not saying that compression at mastering is the real problem here, you're getting sound advice about power and max spl from knowledgable people. But it won't hurt you to read up on dynamic compression and what it's used, and misused, for.
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shawn swanson

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #14 on: July 06, 2014, 02:49:17 pm »

Johannes was not talking about data compression, he was talking about dynamic range compression. Data compression effects the quality of the signal, dynamic range compression raises the average power required.

Thanks Mac.  I sit corrected ;-}  If they are not using a compressor/limiter I will assume this is not the cause of the problem.  Please correct me if I'm wrong.
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Johannes Halvorsen

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #15 on: July 06, 2014, 02:52:37 pm »

Thanks Mac.  I sit corrected ;-}  If they are not using a compressor/limiter I will assume this is not the cause of the problem.  Please correct me if I'm wrong.
As I said: I have heard tracks that was so heavily compressed AT MASTERING that they produced the effect you described WITHOUT an active compressor in the signal chain.
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shawn swanson

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #16 on: July 06, 2014, 03:00:12 pm »

As I said: I have heard tracks that was so heavily compressed AT MASTERING that they produced the effect you described WITHOUT an active compressor in the signal chain.

I was just typing a question on this, and the system alerted me to your new response.  Neat system ;-}.  It is the music itself you are referring too.  I know modern electronica can be pushed so hard that the visual representation of the track can show as pretty much a solid bar instead of a bunch of peaks and valleys.  Maybe Mike is right and though the system can benifit from better power distribution, it still might not be enough to produce the sound they want....
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g'bye, Dick Rees

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #17 on: July 06, 2014, 03:19:48 pm »

I do have some experience with the DJ's that play for this gig.  The majority have been educated about the pitfalls of compression and keep their files at 320kbs or high quality variable.  I know one DJ specifically that has used the system, experienced the problem, and keeps their music files at 320.

As for the Monster Cable box - I would say your probably right Dick.  I think some M.C. gear is pretty good, but all of it has more marketing than substance in it. 

I looked up the Whirlwind distro gear - Sweet!  I would love to play with that stuff but it looks like it's beyond the budget of this group.  This set up is used at Burning Man, a non-commercial festival.  They don't make any money with it, they just do it for fun.  I think I'm going to grab a pile of good quality hardware and rebuild the cord and distribution as I am going to the festival this year and will get my hands on the rig then.

Shawn...

Regarding compression, we're not talking about data/file compression.  We're talking about the dynamically compressed CONTENT of the files.

Live music will have a pretty fair dynamic range, often in excess of 20dB while recorded music...especially DJ tracks these days...may have only 4dB of dynamic range due to severe and repeated application of dynamic compression to make them SEEM as loud as possible.  Heck, 4dB may be a liberal estimate at that.

So the speakers, amps and system ad a whole get no "rest" and are being supplied with what is pretty much maximum voltage constantly.  Not a pretty picture.

Edit:

I see we were all posting the sma info at the same time...
« Last Edit: July 06, 2014, 03:42:15 pm by dick rees »
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Tim McCulloch

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #18 on: July 06, 2014, 03:48:54 pm »

Shawn...

Regarding compression, we're not talking about data/file compression.  We're talking about the dynamically compressed CONTENT of the files.

Live music will have a pretty fair dynamic range, often in excess of 20dB while recorded music...especially DJ tracks these days...may have only 4dB of dynamic range due to severe and repeated application of dynamic compression to make them SEEM as loud as possible.  Heck, 4dB may be a liberal estimate at that.

So the speakers, amps and system ad a whole get no "rest" and are being supplied with what is pretty much maximum voltage constantly.  Not a pretty picture.

Edit:

I see we were all posting the sma info at the same time...

And this leads to "power compression", where the continual application of barely varying voltage to the voice coil results in significant heat rise, which raises the DC resistance of the coil, leading to less voltage getting converted into linear movement of the transducer piston.  You can turn it up, but it doesn't get correspondingly louder.  The isn't likely to be the PRIMARY cause of the trouble presented, it is a factor.

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g'bye, Dick Rees

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Re: EU-6500 running 3500 watts of sound - Volume lowers during heavy bass
« Reply #19 on: July 06, 2014, 03:56:29 pm »

And this leads to "power compression", where the continual application of barely varying voltage to the voice coil results in significant heat rise, which raises the DC resistance of the coil, leading to less voltage getting converted into linear movement of the transducer piston.  You can turn it up, but it doesn't get correspondingly louder.  The isn't likely to be the PRIMARY cause of the trouble presented, it is a factor.

Thanks, Tim.  I was going to include that but the cat urped up a hairball while I was posting and I had to take a housekeeping break...
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