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Old 14th December 2007, 02:32 AM   #11
jol50 is offline jol50  United States
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Means there is not enough room to put much capacitor inside the amp, so they get worked hard....get worked less with an external capacitor, a big cap. This would be a bigger problem for bass guys and running tones.
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Old 14th December 2007, 05:43 AM   #12
Rigs64 is offline Rigs64  Canada
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The way I was told is that a car battery releases it's power at a steady state and doesn't deal with power surge demands from a power hungry amp very well.A 1 farad cap mounted close to the amp after the fuse releases the needed short bursts of power that the amp wants during hard play.The power cap is said to improve the dynamic headroom of the amp by supplying very fast power bursts.

Another take on this is where I work...we use very large capacitor banks to compliment the power supply to all of the d.c. motor drives in the plant.
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Old 14th December 2007, 09:47 AM   #13
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Quote:
Originally posted by 17DoubleE
I believe an external capacitor will off load some the work being done from these internal caps and therefore reduce their temperature rise, extending their life.
Sorry but that is incorrect. The caps inside an amps are in the secondary side and smooth the rectified current from the switch mode converter. So putting caps on the primary side which is where they will be if they are outside the amp, is not going to add to the secondary capacitance.

The reason caps stop dimming is because they average the current, i.e. drag the system down so that the lights don't get back up to full brightness so it appears they don't fluctuate as much.

As I said before, "the big three" wiring upgrade is the way to go.
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Old 14th December 2007, 12:48 PM   #14
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[QUOTE]Originally posted by richie00boy
[B]

Sorry but that is incorrect. The caps inside an amps are in the secondary side and smooth the rectified current from the switch mode converter. So putting caps on the primary side which is where they will be if they are outside the amp, is not going to add to the secondary capacitance.

richie00boy,

I'm refering to the caps on the primary side of the power supply, not those on the secondary....... Perhaps those amps you're familar with didn't have primary side aluminum electrolytics?
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Old 14th December 2007, 01:15 PM   #15
Flyin11 is offline Flyin11  United States
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Well, I'm not sure what I'm going to do yet. First thing first is to look into a new headunit and get that straight as the higher voltage on the preamps completely rocks my system. I was just looking into my RMS wattage on my subs (which is why I was asking about the output on my amp cause I was thinking about getting another amp of the same kind, 1 for each sub, cause some reviewrs said that the amp hits harder on 1 sub than 2 so they would not recommend it on 2 subs) and I thought they were 300w max but they are only 150w. So, 2 subs=300w max power and I have a Alpine putting out 400w. So that's 50w over per sub. I'm not hurting anything because the gain is still down a bit but I was beginning to look into a higher wattage amp to get me more power but that doesn't make any sense now being as I'm already have a bit too much power. Might look into another brand amp to get me the power I want and need cause this one might not be cutting it, or by tax return time, get the next level up JL Audio subs that handle more power and upgrade that way. I know they say to match your RMS range of your subs with your amp and I thought I had done that but it's just not hard enough so I'm thinking the reviewrs might have been right about this amp with 2 subs. First though, I'm waiting to decide on what to do about a new headunit first. A lower wattage amp, maybe 2 channel instead of mono, would work a whole lot better sound wise and efficient wise than what I have.

What works better? A mono class D or a stereo 2 channel amp? I always thought the 2 channel mode was the best way to go and am believing that now...
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Old 14th December 2007, 07:39 PM   #16
shagone is offline shagone  United States
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Quote:
Originally posted by Flyin11
Well, I'm not sure what I'm going to do yet. First thing first is to look into a new headunit and get that straight as the higher voltage on the preamps completely rocks my system. I was just looking into my RMS wattage on my subs (which is why I was asking about the output on my amp cause I was thinking about getting another amp of the same kind, 1 for each sub, cause some reviewrs said that the amp hits harder on 1 sub than 2 so they would not recommend it on 2 subs) and I thought they were 300w max but they are only 150w. So, 2 subs=300w max power and I have a Alpine putting out 400w. So that's 50w over per sub. I'm not hurting anything because the gain is still down a bit but I was beginning to look into a higher wattage amp to get me more power but that doesn't make any sense now being as I'm already have a bit too much power. Might look into another brand amp to get me the power I want and need cause this one might not be cutting it, or by tax return time, get the next level up JL Audio subs that handle more power and upgrade that way. I know they say to match your RMS range of your subs with your amp and I thought I had done that but it's just not hard enough so I'm thinking the reviewrs might have been right about this amp with 2 subs. First though, I'm waiting to decide on what to do about a new headunit first. A lower wattage amp, maybe 2 channel instead of mono, would work a whole lot better sound wise and efficient wise than what I have.

What works better? A mono class D or a stereo 2 channel amp? I always thought the 2 channel mode was the best way to go and am believing that now...

it all depend on your power requirments and the subs you are trying to push. sound quality wise, I tend to prefer a standard class A/B amp with bipolar outputs over a class D amp or even a class A/B with mosfet outputs. there are exceptions of coarse. shop around and listen to a few different systems first. make sure the output gain from your head unit is compatible with the amp you choose and that you have the correct crossover options available as well. your sub enclosure and positioning will have a big influence on sound as well. are your subs in the recommended enclosure size?
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Old 14th December 2007, 07:46 PM   #17
Flyin11 is offline Flyin11  United States
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Sub type, enclosure, sub size are all no problems...I love my subs...Just trying to get everything else straight. Made adjustments to the inside of the box a few weeks ago and knocked the internal cubic footage down from 1.37 to 1.27 per chamber...JL recommends 1.25 cu ft. so I'm about right on with no worries...
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Old 14th December 2007, 07:50 PM   #18
jol50 is offline jol50  United States
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You will need a fairly expensive single sub for 400wrms if you beat it hard. That amp should hit pretty hard for a daily driver. What kind of box makes more difference how they work than the sub for the most part.
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Old 14th December 2007, 08:31 PM   #19
Flyin11 is offline Flyin11  United States
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I just find it pretty hard to believe that the amp is really hitting that hard you know? I mean, if I'm sitting there with +50 watts more that the peak of the sub and my gain is 1 notch from max...It's not really mving me that much...It's just doesn't sound like it's doing it's job. I mean, if it was really hitting it hard then the gain would be say halfway...not almost full. So, maybe I need to try another amp. Or, heck...maybe I need to go to 15" speakers for my rock music...I mean, I thought 12's were suppose to be very loud These are the answers I'm trying to find out about my system...If Alpines are such good amps, why isn't it driving it hard enough?
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Old 14th December 2007, 08:42 PM   #20
jol50 is offline jol50  United States
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If it has some kind of problem, I guess you would need to describe what you have like wire sizes, box size/wood thickness/porting, how it is in what type of vehicle, HU and output voltage, any processors, using RCA input?, all that stuff. You should feel 400wrms no problem, I sure do and mine are less efficient IB that like to hit 30Hz not 50 as much. So they are not as 'loud', but they have the thunder and I can feel the thunder and the punch when they are cranked up. In fact my high side just gets blown away by the subs its ridiculous....and why I am dumping the big kicker because it does not have any power at 4 ohms as 4ch. Unless you mistakenly have it wired at 8 ohms or something, that will chop the power down.
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