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Thread: Setting gains volt-ohm meter like in the JL tutorial...other brands??? |
    
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| Posted on Wednesday, September 15, 2004 - 10:33 pm: |
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ok...i see in the tutorial on JL.com that you can set gains on JL amps by using a volt-ohm meter, but what about w/ other brands???
i wanna use my volt-ohm meter to set gains on my JBL BP600.1, so what would the output voltage be at 1ohm?
is there a formula to find an amps unclipped output voltage??? |
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Bronze Member Username: Fishy
Tamarac,
FL
USA
Post Number: 40
Registered: Sep-04
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| Posted on Wednesday, September 15, 2004 - 11:33 pm: |
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yep
P = V^2/Z => V = (PZ)^1/2
i.e.
Voltage = the squareroot of Power x Impedance
So 1) Figure out what impedance your gonna be running ur amp at.
2) Multiply that by what the rated power is at that load.
3) Take the squareroot of that figure and that should give you what the output voltage should be.
You can check this formula out with JL's specs for each load. I got real close to 500 watts for each load for the 500/1
[note] don't forget to measure off the bridged outputs if your bridging the amp.
-Fishy
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Bronze Member Username: Fishy
Tamarac,
FL
USA
Post Number: 42
Registered: Sep-04
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| Posted on Wednesday, September 15, 2004 - 11:57 pm: |
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Oh yeah. I think I might go try setting my gains like this. Where would one aquire one of those test tone CD's or whatever they are?
-Fishy |
Silver Member Username: Southernrebel
Louisiana
USA
Post Number: 184
Registered: Mar-04
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| Posted on Thursday, September 16, 2004 - 12:59 am: |
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you could download a sine-wave (tone) generator and create your own test CD...
here it the one i use:
www.nch.com.au/tonegen
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Bronze Member Username: Fishy
Tamarac,
FL
USA
Post Number: 49
Registered: Sep-04
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| Posted on Thursday, September 16, 2004 - 01:47 am: |
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cool, thanks |
Silver Member Username: Insearchofbass
Post Number: 570
Registered: Jun-04
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| Posted on Friday, September 17, 2004 - 10:41 pm: |
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this is cool info thanks guys |
Bronze Member Username: Fishy
Tamarac,
FL
USA
Post Number: 80
Registered: Sep-04
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| Posted on Saturday, September 18, 2004 - 05:58 am: |
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Hey sean, Jonathan said something about using a dummy resistor matching your speaker load if your amp doesn't have a regulated power supply. I still don't understand why this is necessary, but someone was doin this with a BP600.1 and apparently couldn't get the voltage high enough w/o using a 1 ohm resistor. What was strange was once he got the voltage and removed the load his voltage stayed the same.
I don't get it but it seems a dummy resistor may be necessry to use this method with amps with unregulated power supplies.
-Fishy |
Silver Member Username: Insearchofbass
Post Number: 578
Registered: Jun-04
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| Posted on Saturday, September 18, 2004 - 02:30 pm: |
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thanks fishy well have to ask jon why this happens |
Gold Member Username: Jonathan_f
GA
USA
Post Number: 1691
Registered: May-04
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| Posted on Saturday, September 18, 2004 - 02:38 pm: |
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I answered that on this thread:
http://forum.ecoustics.com/bbs/messages/4/94353.html
It'll explain to anyone curious about this. |
Silver Member Username: Insearchofbass
Post Number: 579
Registered: Jun-04
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| Posted on Saturday, September 18, 2004 - 02:41 pm: |
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thanks jon just read it |
