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Old 27th September 2012, 10:59 AM   #1681
djk is offline djk
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Half gain means nothing in terms of output power, even with the gain turned down to half you can still drive the amplifier into clipping.

You would need a limiter between the crossover and the amplifier to set a power limit.
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Old 27th September 2012, 11:05 AM   #1682
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heres my setup. i run the mixer just under the red on the output side, the EQ is set to boost the signal 6db, and from there, the sub amp (EP4000) is set just under half.

so whatever that is, thats what it is. it has a ton of power in reserve for what i do. so im well and truly happy with that. especially as i add more subs to it. im pretty confident it will easily handle another four. because its not even running bridged. just left/right outputs.

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Old 27th September 2012, 11:32 AM   #1683
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Quote:
Originally Posted by AndrewT View Post
What does this mean?
Quote:
Originally Posted by djk View Post
Half gain means nothing in terms of output power, even with the gain turned down to half you can still drive the amplifier into clipping.

You would need a limiter between the crossover and the amplifier to set a power limit.
What they're saying is it's possible your amp could start clipping after one more "click' of the knob. The position of the knob doesn't always determine how much power/voltage you're sending the drivers/speakers.

"Got it on half" might mean something if you also know that it clips only when "turned all the way up", or better yet, if you had a processor that allowed you to raise & lower gain by a certain dB amount t have a better understanding of how much headroom you have available.

"Got it on half" could be 20+dB away from clipping and then again, could be 1dB away from clipping. It not only depends on how your EQ and mixer are set up, but also the material/music/audio energy you're feeding the amplifier. All of these things must be taken into account. And before the clip point is determined (should do this first, speaker unplugged) you won't have a relative point to what "half way" really is, other than a physical position.
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Old 27th September 2012, 11:35 AM   #1684
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ok, well how's this for reference then.

the party i did when i blew up my first drivers in the SS15 horns, i had the amp a bit over 3/4 of which it was just starting to flicker the clip light.

so as far as im concerned, its on half.
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Old 27th September 2012, 11:39 AM   #1685
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Were the same drivers used? Do they have the same Re? Was the mixer & EQ set up exactly the same? Did the clip light flicker brighter/lighter during different songs?
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Old 27th September 2012, 11:45 AM   #1686
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next time i have access to a volt meter and have the subs going as hard as they need to, ill measure it.

i still refer to it as half. and yes, im well aware of the variables. generally, i refer to my mixer as the constant. for the fact that it controls the volume. because once set, the EQ and the amps tend not to get adjusted once set for each venue. the EQ output gain has never moved in the time ive owned it, and the bass freqencies are all flat up to 80hz. so, i keep the input signal (output on mixer) at approximately the same maximum level regardless of music being played. its always levelled out to just under the clip light.

beyond that, who knows. maybe its not half... maybe its more, maybe its less. i know it runs hard, and sounds absolutely incredible.
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Old 27th September 2012, 11:56 AM   #1687
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Originally Posted by klampykixx View Post
i keep the input signal (output on mixer) at approximately the same maximum level regardless of music being played. its always levelled out to just under the clip light.
Well, that's good for DJ purposes, for a few reasons.

Quote:
Originally Posted by klampykixx View Post
next time i have access to a volt meter and have the subs going as hard as they need to, ill measure it.

...beyond that, who knows. maybe its not half... maybe its more, maybe its less. i know it runs hard, and sounds absolutely incredible.
Well, 1) you could turn the amp up to the clip flicker and back it off a notch or two (note the spot where the clip light illuminated)

and 2) where it flickered last time at "3/4," I would typically call that 9/10. I don't like sending any of my drivers a clipped signal from the amp.

Do you have the limiter on your amplifier engaged?
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Old 27th September 2012, 11:57 AM   #1688
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yep. limiter engaged. i never drive amplifiers past clipping point. 1, its pointless. 2, its deadly for the speaker.
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Old 27th September 2012, 12:22 PM   #1689
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Seeing as you have your limiter engaged, you might be able to worry less. If it works anything like the limiter on my PLX3402, you'd have to drive it so hard into the (now) limit light to get near voltage at actual clipping level. When you get that volt meter, check it out - you might find interesting results with the limiter on & off (subs disconnected), as the limiter reduces voltage quite a bit as the light gets flickering... And now that light is your indicator of the limiter being active opposed to your amp clipping.
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Old 27th September 2012, 12:37 PM   #1690
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As far as control goes where in the signal cnain is the "volume" knob?

It seems that depending on setup its different.

In car audio theres a lot of potential for ground loops and other chassis noise to creep into. Signal cables so we used line drivers to boost signals to 15-20 volts.

As long as low level pre driver cables were short, 6" from source to driver, noise was less a problem.

As far as clipping the amp we could close down the gains completely and so never clip the input to the amp.

Now sometimes we would optimize the gain structure, zero clipping, right up to the amps and let them clip just a hair so it"sounded louder". Some guys thought that a completely clean system was a little too reserved.

These days head units have 6 volt outputs so its not so necessary for a line driver.

Just my thoughts. Thx for reading.
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