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Thread: The Amplifier doesn't put out more volume when i use more than half its real volume .... What is clipping and how can i arange it ?? |
    
SPLtesting Unregistered guest |
| Posted on Saturday, May 08, 2004 - 07:29 pm: |
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I have an amplifier with a 12" sub in a custom 40Hz bassbox ... I took it for an SPL test and i reached only 142.7DB... The problem is that i did that with half the volume on the amp cause the amp doesn't put out more volume when i turn the nobe... My friend said that it could be clipping... I used an exide maxxima battery and the volume went as low as 11.3V .... What must i do to make my amp use all the power from the sub ??? Change my alternator and add a battery ???? |
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| Posted on Saturday, May 08, 2004 - 07:35 pm: |
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i think you'l find that 142db's is quite a lot for 1 12" sub, what amp+sub do you use? |
SPLtesting Unregistered guest |
| Posted on Saturday, May 08, 2004 - 07:56 pm: |
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Boss pd-4000 and a power aqoustik mofo 12"
No its not enough....
The amp is only putting 600-700Watts at the voltage as low as 11.3volts... |
SPLtesting Unregistered guest |
| Posted on Saturday, May 08, 2004 - 07:58 pm: |
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I need to do at least 149DB's to be a goos SPL competitor with one 12" subwoofer...
Any help ?????? |
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| Posted on Saturday, May 08, 2004 - 08:33 pm: |
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JL audio 12w7 +JL1000.1 amp, you'l push well over 149db with it set properly |
Gold Member Username: Glasswolf
NorthWest,
Michigan
USA
Post Number: 2770
Registered: Dec-03
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| Posted on Sunday, May 09, 2004 - 02:55 am: |
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your problem, honestly, is that you need to learn more about car audio and electronics.
the gains on your amp have no effect on the power output. they are only to balance the line voltage to the input stage of teh amp.
if you have them turned up more than half way, the amp is almost surely clipping and causing damage to the sub.
what you need is a high output alternator, and probably another 12" sub, or ideally, better subs, and a better amp.
you're using products from low quality companies, and with that in mind you won't win any competitions.
Money is a big part of competing.
Get used to that.
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SPLtesting Unregistered guest |
| Posted on Sunday, May 09, 2004 - 03:10 am: |
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So will the alternator effect when the car engine is not running ???? Will 150amp be enough for 1200 RMS ??? I have a 70A stock alternator and i did 142.7DB  - with 600-700watts RMS .. So if i change the alternator i will make over 142.7DB..? Do i need to change the battery ?? if it went down as 11.3V ... I have a Maxxima Exide Battery 900Ca ... Do i Need Another Battery ?? Please Help i need kick kick my friends a$$ .... |
SPLtesting Unregistered guest |
| Posted on Sunday, May 09, 2004 - 05:29 am: |
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Does the alternator effect the sound if the ENGINE IS NOT RUNNING ???? |
Gold Member Username: Glasswolf
NorthWest,
Michigan
USA
Post Number: 2781
Registered: Dec-03
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| Posted on Sunday, May 09, 2004 - 11:55 am: |
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ok one thing at a time here..
1: no, the alternator will not have any real noticeable effect on the engine. There will be a very slight increase in drag on the belts, but at most, it'd be maybe a couple horsepower? Nothing you'd even come close to feeling, but from a purely physics standpoint, you can't pull energy out of thin air, so yeah the engine still has to work just a little bit more to spin the bigger alternator. I had a 150A in a Festiva though and couldn't feel the difference in how the motor ran, so it's nothing that bad.
2: a 1200w amp will draw ~114A continuous at full output. The 50A alternator should work well enough for that amp. Especially for SPL comps, since burping only draws peak power for a brief moment.
3: I don't know that the alternator will increase SPL for sure, but it will prevent clipping in the amp, which in turn will prevent blowing the subs.
There are amny things to do for increasing SPL, such as dynamatting the car, designing a better 6th order bandpass box for the subs, and so forth.
4: the battery should be alright, although deep cycles with an isolator would help when the motor is shut off in competitions.
5: 11.3VDC indicates sagging voltage rails because the batteries can't handle the load when the motor is off, or the alternator can't cope when the engine is running.
Ideally, compete with the motor running and above idle for a good voltage.
6: the alternator only helps when the engine is running, that is correct.
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SPLtesting Unregistered guest |
| Posted on Sunday, May 09, 2004 - 12:28 pm: |
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thanks glasswolf, would you accept head from me? |
Gold Member Username: Glasswolf
NorthWest,
Michigan
USA
Post Number: 2787
Registered: Dec-03
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| Posted on Sunday, May 09, 2004 - 10:37 pm: |
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heh
sorry, job's already filled.
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