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Thread: Jl Audio 500/1 at 8 ohms |
    
Bronze Member Username: Nutshmeg
Post Number: 17
Registered: Mar-05
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| Posted on Friday, April 01, 2005 - 12:05 pm: |
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This amp is stated to deliver it's 500w output between 1.5 and 4 ohms, any idea what would happen at 8 ohms? Would it ramp the current draw out of sight? |
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Silver Member Username: Tragedy
San Jose,
CA
Post Number: 173
Registered: Feb-05
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| Posted on Friday, April 01, 2005 - 02:21 pm: |
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at 8ohms i would expect around 250watts. |
Silver Member Username: Tragedy
San Jose,
CA
Post Number: 174
Registered: Feb-05
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| Posted on Friday, April 01, 2005 - 02:22 pm: |
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ramp the current draw out of sight? not sure if you mean more or less but 8ohms would require less of a current draw. |
Gold Member Username: Jonathan_f
GA
USA
Post Number: 3573
Registered: May-04
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| Posted on Friday, April 01, 2005 - 03:17 pm: |
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It would draw less current as stated. The 500/1 works via voltage rails and has different rails depending on the load presented and voltage present to the amplifier. At 8 ohms, the amplifier would remain on the same voltage rail (highest) as it would for 4 ohms, power output would be similar to other amplifiers in that regard, you can expect a little more than 250W due to the efficiency/headroom of an amp with a higher impedance. I'd say closer to 300ish with that load, especially since the amp is underrated. |
Silver Member Username: Fishy
Tamarac Ft.Laud,
FL
USA
Post Number: 805
Registered: Sep-04
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| Posted on Friday, April 01, 2005 - 04:03 pm: |
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Long Answer
Besides tube amps all of today's car amplifiers can be viewed as simple voltage sources which are limited in output by the maximum amount of voltage they can produce. Given an adequate power supply this max voltage is determined by the amplifier's "voltage rail".
If I understand the way those slash series amps work they have three voltage rails, the highest being utilized at 4 ohms. When you hook up lower impedance loads the amp automatically switches to a lower voltage rail to limit power. However, with any higher impedance your stuck utilizing the "4 ohm rail" and the maximum amount of voltage the output circuitry using this rail can produce, call it V4ohm.
When utilizing this voltage rail the maximum amount of power that can be produced is given by
Pmax=V4ohm^2/R
so doubling the impedance essentially halves your potential power output just like it would on any "single rail" amplifier.
Short Answer
About 250 watts @ 8 ohms
-Fishy |
Silver Member Username: Fishy
Tamarac Ft.Laud,
FL
USA
Post Number: 806
Registered: Sep-04
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| Posted on Friday, April 01, 2005 - 04:04 pm: |
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Dayum, guess I shouda finished that post quicker. Jonathan beat me to the punch.
:P
-Fishy |
Silver Member Username: Tragedy
San Jose,
CA
Post Number: 175
Registered: Feb-05
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| Posted on Friday, April 01, 2005 - 04:13 pm: |
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lol fishy |
Silver Member Username: Fishy
Tamarac Ft.Laud,
FL
USA
Post Number: 807
Registered: Sep-04
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| Posted on Friday, April 01, 2005 - 04:42 pm: |
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Oh well, hehe.
At least I figured out how to use subscripts. Still like Jonathan's answer better.
-Fishy |
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| Posted on Friday, April 01, 2005 - 05:55 pm: |
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I have a question, firstly let me start off my saying, i recently bought 2 brand new 1600 w/max amplifiers and 4 12" 600w/max new subwoofers. the Brand is CUSPID, i never heared of it before, but for the price i thought i would give it a try. Are these CUSPID things any good? please leave me some first or second hand accounts you had with this equipment.
PS- the amplifier is a 4-channel but is 2x80wt RMS, does that make any sense? |
