Question About Settings Gains With Volt Meter
09-29-2009, 11:53 AM
#1
0 Watt CAFz'r
Thread Starter
Join Date: Sep 2009
Posts: 11
Question About Settings Gains With Volt Meter
Have an Alpine SWE-1043 powered by and Alpine MRP M500.
Alpine MRP M500
mono subwoofer car amplifier
300 watts RMS x 1 at 4 ohms (500 watts RMS x 1 at 2 ohms)
variable low-pass filter (50-200 Hz, 24 dB/octave)
variable bass boost (0-12 dB at 50 Hz)
subsonic filter (15 Hz, 24 dB/octave)
Alpine SWE-1043
frequency response: 29-1,000 Hz
power range: 100-250 watts RMS
peak power: 700 watts
sensitivity: 84 dB
After some research into regards to setting the gains for my amp, I came across Sparky’s (top contributor) Guide. http://www.datafilehost.com/download.php?file=6d26c621
It says that the Volt Meter should read around 31.62 V in regards to my setup’s 250 watt (lowest of the sub/amp combo) to my 4 ohm Impedance.
1) My question is in regards to tone and frequency settings. He offers a 60hz 0db, but other videos use a 50 Hz 0db tone. Which is better or should I stick with the tone that he uses with his excel file where all his calculation are?
Secondly my amp has 3 controls Gain, Bass EQ [0db-12db], an the LP Filter [50 Hz-200Hz].
2) Should I set all these level to the minimum and just adjust the Gain. I read since I’m just powering the sub with the amp, to leave the LP Filter to the Hz I’m using at the deck is this true? If so what’s the best to use (80Hz?) and what should I do the Bass EQ Filter setting.
My Head unit has these options
Bass Control:
Bass Centre Frequency: 60Hz, 80Hz (default), 100Hz, or 200Hz
Bass Band Width: 1 (narrow) to 4 (wide)
Bass Level: -7 to +7 (+/-14dB in 2dB steps)
Treble Control:
Treble Centre Frequency: 10kHz (default), 12.5kHz, 15kHz, or 17.5kHz
Treble Level: -7 to +7 (+/-14dB in 2dB steps)
Which setting would be recommended>? Thanks In Advance!
Alpine MRP M500
mono subwoofer car amplifier
300 watts RMS x 1 at 4 ohms (500 watts RMS x 1 at 2 ohms)
variable low-pass filter (50-200 Hz, 24 dB/octave)
variable bass boost (0-12 dB at 50 Hz)
subsonic filter (15 Hz, 24 dB/octave)
Alpine SWE-1043
frequency response: 29-1,000 Hz
power range: 100-250 watts RMS
peak power: 700 watts
sensitivity: 84 dB
After some research into regards to setting the gains for my amp, I came across Sparky’s (top contributor) Guide. http://www.datafilehost.com/download.php?file=6d26c621
It says that the Volt Meter should read around 31.62 V in regards to my setup’s 250 watt (lowest of the sub/amp combo) to my 4 ohm Impedance.
1) My question is in regards to tone and frequency settings. He offers a 60hz 0db, but other videos use a 50 Hz 0db tone. Which is better or should I stick with the tone that he uses with his excel file where all his calculation are?
Secondly my amp has 3 controls Gain, Bass EQ [0db-12db], an the LP Filter [50 Hz-200Hz].
2) Should I set all these level to the minimum and just adjust the Gain. I read since I’m just powering the sub with the amp, to leave the LP Filter to the Hz I’m using at the deck is this true? If so what’s the best to use (80Hz?) and what should I do the Bass EQ Filter setting.
My Head unit has these options
Bass Control:
Bass Centre Frequency: 60Hz, 80Hz (default), 100Hz, or 200Hz
Bass Band Width: 1 (narrow) to 4 (wide)
Bass Level: -7 to +7 (+/-14dB in 2dB steps)
Treble Control:
Treble Centre Frequency: 10kHz (default), 12.5kHz, 15kHz, or 17.5kHz
Treble Level: -7 to +7 (+/-14dB in 2dB steps)
Which setting would be recommended>? Thanks In Advance!
09-29-2009, 12:50 PM
#2
first thing is in regards to which frequency to test with, I would say try the 60. I used 50 when I hooked up my DMM because with the same gains at 60 the voltage dropped, so try the 60, then after your gains are set, test the 50, if your volts at the amp go up, then use the 50. Even better would be to try a bunch of different tones to see how the voltage changes. Personally I think 50 is the best, but like I said, tune with 60, then run a 50 and see what the reading is.
as for the amp, first thing I would do is set the LPF around 80 hz, as that is typically the standard for amps that don't give you a choice on where to set it. I would then say that to get the 31 volts you should try and find a combo of gain and bass eq, but personally I like to make sure that my gain is higher than bass boosts in an attempt to use the least amount of bass boost as possible.
The head unit stuff I would say use what sounds best, just remember those bass options will affect the voltage at your amp
as for the amp, first thing I would do is set the LPF around 80 hz, as that is typically the standard for amps that don't give you a choice on where to set it. I would then say that to get the 31 volts you should try and find a combo of gain and bass eq, but personally I like to make sure that my gain is higher than bass boosts in an attempt to use the least amount of bass boost as possible.
The head unit stuff I would say use what sounds best, just remember those bass options will affect the voltage at your amp
09-29-2009, 03:22 PM
#4
the equation used to calculate power will change based on the frquency so the calculator will not be accurate if you use a different frequency, (look up calculating impedance with a inductor) (impedance is like resistance) (AC has phase angles)
Nick
Nick
09-29-2009, 03:24 PM
#5
Administrator
Join Date: Feb 2006
Posts: 16,855
This exercise is futile - well, unless you are doing it just to fiddle and waste your time..
The problem is right here:
While the sticker on the magnet says 4 ohms, the driver isn't 4 ohms. And once the driver is in a box, in your car, it FOR SURE isn't 4 ohms. And should you find yourself able to measure the impedance of the driver, in a box, in a car, at a specific frequency; once that frequency changes, the impedance will too so then what do you do?
Set your gain by ear - it's the most sophisticated tool you own and coincidentally it's what you are going to use to listen to your system as well...
People spend way too much time overthinking things. I have told people the following for 20 years now and it will help you set your gains and it will save your speakers:
If it sounds bad, turn it down.
The problem is right here:
It says that the Volt Meter should read around 31.62 V in regards to my setup’s 250 watt (lowest of the sub/amp combo) to my 4 ohm Impedance.
Set your gain by ear - it's the most sophisticated tool you own and coincidentally it's what you are going to use to listen to your system as well...
People spend way too much time overthinking things. I have told people the following for 20 years now and it will help you set your gains and it will save your speakers:
If it sounds bad, turn it down.
09-29-2009, 05:12 PM
#6
This exercise is futile - well, unless you are doing it just to fiddle and waste your time..
While the sticker on the magnet says 4 ohms, the driver isn't 4 ohms. And once the driver is in a box, in your car, it FOR SURE isn't 4 ohms. And should you find yourself able to measure the impedance of the driver, in a box, in a car, at a specific frequency; once that frequency changes, the impedance will too so then what do you do?
Set your gain by ear - it's the most sophisticated tool you own and coincidentally it's what you are going to use to listen to your system as well...
People spend way too much time overthinking things. I have told people the following for 20 years now and it will help you set your gains and it will save your speakers:
If it sounds bad, turn it down.
While the sticker on the magnet says 4 ohms, the driver isn't 4 ohms. And once the driver is in a box, in your car, it FOR SURE isn't 4 ohms. And should you find yourself able to measure the impedance of the driver, in a box, in a car, at a specific frequency; once that frequency changes, the impedance will too so then what do you do?
Set your gain by ear - it's the most sophisticated tool you own and coincidentally it's what you are going to use to listen to your system as well...
People spend way too much time overthinking things. I have told people the following for 20 years now and it will help you set your gains and it will save your speakers:
If it sounds bad, turn it down.
I love this forum. 
09-30-2009, 08:34 AM
#7
0 Watt CAFz'r
Thread Starter
Join Date: Sep 2009
Posts: 11
Yea it seems like a lot of effort for every average person putting in a sub to go through when installing. But hey, if it prevents me from blowing my new sub and or amp ill do it,(I’m a very tedious person who likes to get perfect and I’m new to the audio department) & since I did purchase it from an American retailer (brokerage fees are a joke) I really don’t want to send it back for repair. I'm just looking for a starting point.
In regards to the above comment about it being hard on the speakers, I had a question about that. Would the tone (60Hz) that I haft to play off the cd not hurt the other speakers that I have plugged in to the stock speaker spots (Polk Db651’s). They say that I should do the test with the sub woofer disconnected and have the volume to up high ¾ of the way. Should the speakers be disconnected as well?
Basically the only reason I’m going through this much trouble is to show a couple buddies of mine that my setup is decent, went through a lot of work picking out the best entry level items, so I hope I’m right. Their rocking those mtx’s with the gain cranked and the music completely washed out by the bass. I’m looking for nice clean bass to accompany the music as I’m not listening to rap all the time. Thanks for the advice everyone.
In regards to the above comment about it being hard on the speakers, I had a question about that. Would the tone (60Hz) that I haft to play off the cd not hurt the other speakers that I have plugged in to the stock speaker spots (Polk Db651’s). They say that I should do the test with the sub woofer disconnected and have the volume to up high ¾ of the way. Should the speakers be disconnected as well?
Basically the only reason I’m going through this much trouble is to show a couple buddies of mine that my setup is decent, went through a lot of work picking out the best entry level items, so I hope I’m right. Their rocking those mtx’s with the gain cranked and the music completely washed out by the bass. I’m looking for nice clean bass to accompany the music as I’m not listening to rap all the time. Thanks for the advice everyone.
11-11-2009, 01:06 AM
#9
0 Watt CAFz'r
Join Date: Dec 2008
Posts: 18
to set your amps with a dmm UNPLUG ALL SPEAKERS, your deck should be at 3/4 volume and all your bass, mid ,treble should be set to flat(or zero).
I used to be able to set my amps gains by ear, but now my ears are starting to fail me (getting old I guess) I just tried this meathod with my PG MS275 and it plays flawless at all volumes, no clipping at all, try both methods and see how good your ears are!!!
I used to be able to set my amps gains by ear, but now my ears are starting to fail me (getting old I guess) I just tried this meathod with my PG MS275 and it plays flawless at all volumes, no clipping at all, try both methods and see how good your ears are!!!
11-17-2009, 09:43 PM
#10
This exercise is futile - well, unless you are doing it just to fiddle and waste your time..
The problem is right here:
While the sticker on the magnet says 4 ohms, the driver isn't 4 ohms. And once the driver is in a box, in your car, it FOR SURE isn't 4 ohms. And should you find yourself able to measure the impedance of the driver, in a box, in a car, at a specific frequency; once that frequency changes, the impedance will too so then what do you do?
Set your gain by ear - it's the most sophisticated tool you own and coincidentally it's what you are going to use to listen to your system as well...
People spend way too much time overthinking things. I have told people the following for 20 years now and it will help you set your gains and it will save your speakers:
If it sounds bad, turn it down.
The problem is right here:
While the sticker on the magnet says 4 ohms, the driver isn't 4 ohms. And once the driver is in a box, in your car, it FOR SURE isn't 4 ohms. And should you find yourself able to measure the impedance of the driver, in a box, in a car, at a specific frequency; once that frequency changes, the impedance will too so then what do you do?
Set your gain by ear - it's the most sophisticated tool you own and coincidentally it's what you are going to use to listen to your system as well...
People spend way too much time overthinking things. I have told people the following for 20 years now and it will help you set your gains and it will save your speakers:
If it sounds bad, turn it down.
I agree 100%! The only time i use a DMM to set gains is when i have a DVC subwoofer and am using one amp per coil, this isn't ideal but i've never had a problem with it. An o-scope would be best when using multiple amps on one sub.
I once ran 4 RF monoblocks on a Mmats Juggernaut with great results all done with a meter.
