***How to set the gains with a multimeter.***
09-27-2006, 08:37 PM
#12
who says that an el cheap multimeter is only good at 60Hz?
My 30 year old el cheap analog volt ohm meter is flat to over 10KHz. I tested it..
It is easy to test, just use a test tone generator on your pc and connect the voltmeter to the audio outputs..
And as long as you are measureing a good sine, you dont need a true RMS. You only need a True RMS if you want to measure the RMS voltage of a very distorted, non sine signal.
As for a 4 ohm 10Watt resistor on water? Duh?....you want to make coffee testing a 500watt sub amp?
My 30 year old el cheap analog volt ohm meter is flat to over 10KHz. I tested it..
It is easy to test, just use a test tone generator on your pc and connect the voltmeter to the audio outputs..
And as long as you are measureing a good sine, you dont need a true RMS. You only need a True RMS if you want to measure the RMS voltage of a very distorted, non sine signal.
As for a 4 ohm 10Watt resistor on water? Duh?....you want to make coffee testing a 500watt sub amp?
09-27-2006, 08:41 PM
#13
we were talking about DMM's, which are DIGITAL multimeters, analog are always true RMS, digital meters are usually built with a bit of a "cheat" factor, assuming that they will only be used on 60 Hz.
09-27-2006, 10:46 PM
#15
yea, I think sass just pointed out something very usefull!
although you still need to know impedance of your speaker or load down the amp for a good measurment...
I also assume you checked out carsound and read about 3:1 gain overlap.... and came to conclusions of where your system needs to be set......
although you still need to know impedance of your speaker or load down the amp for a good measurment...
I also assume you checked out carsound and read about 3:1 gain overlap.... and came to conclusions of where your system needs to be set......
09-27-2006, 10:51 PM
#16
Originally Posted by zoomer
who says that an el cheap multimeter is only good at 60Hz?
My 30 year old el cheap analog volt ohm meter is flat to over 10KHz. I tested it..
It is easy to test, just use a test tone generator on your pc and connect the voltmeter to the audio outputs..
And as long as you are measureing a good sine, you dont need a true RMS. You only need a True RMS if you want to measure the RMS voltage of a very distorted, non sine signal.
As for a 4 ohm 10Watt resistor on water? Duh?....you want to make coffee testing a 500watt sub amp?
My 30 year old el cheap analog volt ohm meter is flat to over 10KHz. I tested it..
It is easy to test, just use a test tone generator on your pc and connect the voltmeter to the audio outputs..
And as long as you are measureing a good sine, you dont need a true RMS. You only need a True RMS if you want to measure the RMS voltage of a very distorted, non sine signal.
As for a 4 ohm 10Watt resistor on water? Duh?....you want to make coffee testing a 500watt sub amp?
09-28-2006, 07:34 AM
#19
^maybe not bad advice... most ppl just set gains by ear/common sense...
'if it sounds distorted turn it down...'
if you think you have a clean signal but are still worried that you might overpower the speakers thermally.... then worry about checking voltage...
when setting up, I would assume a 2h power rating... so if your speakers are 30watts RMS don't give them 50 for more then an hour or so.... get the idea ?
'if it sounds distorted turn it down...'
if you think you have a clean signal but are still worried that you might overpower the speakers thermally.... then worry about checking voltage...
when setting up, I would assume a 2h power rating... so if your speakers are 30watts RMS don't give them 50 for more then an hour or so.... get the idea ?
09-28-2006, 07:54 AM
#20
Originally Posted by Sassmaster
we were talking about DMM's, which are DIGITAL multimeters, analog are always true RMS, digital meters are usually built with a bit of a "cheat" factor, assuming that they will only be used on 60 Hz.
Analog meters are not always true RMS> the movement response, frequency response of the circuitry etc will all contribute to wether it can read true RMS. If you really want to know.. go here
http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=458358&nid=-536902435.536880933.02&id=458358
as for DMM, it depends on the specs. I just tested my HP DMM and it is good to about 1Khz.
What I am getting at is that it is very very simple to test your DMM with your PC soundcard.
as for the overall issue of blowing speakers.. the first rule is to listen.. if it sounds distorted... turn down the volume. If you dont know how to listen for distortion.... learn!.
If you cant hear your tweeters and midbass distorting because of your 1000 watt sub... get a life!
