the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
icon

multimeters


Post ReplyPost New Topic
< Prev Topic Next Topic >
xTimx 
Copper - Posts: 354
Copper spacespace
Joined: September 13, 2002
Location: Canada
Posted: May 15, 2004 at 1:27 PM / IP Logged  
ok two Q's here. how do you use one and what type of one should i buy!?
xTimx
kgerry 
Platinum - Posts: 3,455
Platinum spaceThis member consistently provides reliable informationspace
Joined: February 07, 2004
Location: Saskatchewan, Canada
Posted: May 15, 2004 at 1:36 PM / IP Logged  
depends on what you are using it for..... what are you planning to test?????
Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
DYohn 
Moderator - Posts: 10,741
Moderator spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: April 22, 2003
Location: Arizona, United States
Posted: May 15, 2004 at 1:41 PM / IP Logged  

I use a Fluke model 70 or 77 for basic ohms and voltage tests and a model 85 for more sophisticated tests.  I am reluctant to try and describe a "how to", but you could start with a web-based tutorial like this one: http://www.multimeterwarehouse.com/usingamultimeter.htm

The best suggestion I could probably give is for you to seek out a basic electricity or introduction to electronics course at a local community college or high school.

Support the12volt.com
xTimx 
Copper - Posts: 354
Copper spacespace
Joined: September 13, 2002
Location: Canada
Posted: May 15, 2004 at 8:27 PM / IP Logged  
well i was wondering how to set up the amplifiers gain setting with a multimeter. but since i dont know the volts for each ohm and such. i was referring to the tutorial off of JL's website to do the gain setting. does that only work with the JL amps? or can they work with all amps?
also when doing this..do i use AC or DC for determining the output of volts!?
my system is:
1= 301x RF amp 4 channel running front and rear speakers at 4 ohms
1= 400S RF amp 2 channel running subs at 6ohms
xTimx
casedeez 
Copper - Posts: 160
Copper spacespace
Joined: April 21, 2004
Location: United States
Posted: May 15, 2004 at 10:50 PM / IP Logged  

Unless you know what your doing, its a pain in the arse. If however you want to play with it by all means go ahead. When your using the meter on the amp you'll want to use the AC setting. If you want to get a whole lot of information you could check out my latest post. Theres about 4 pages of information on there. Personally the only thing I woudl suggest about using a multimeter and setting your gains is if you have two amps just use the meter to make sure both amps are set at the same level. Other than that its really not worth your time. (my opinion) Plus you'd have to get a test cd and if you buy one theyre generally aroiund the 25 dollar range. Anyway IO hope this helps and if your honest about doing it check out my post so everyone doesnt have to repeat everything they just typed to me!!!

Cheers

DYohn 
Moderator - Posts: 10,741
Moderator spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: April 22, 2003
Location: Arizona, United States
Posted: May 16, 2004 at 9:10 AM / IP Logged  
casedeez, I know the process seemed to escape you, but saying somethng like "it's really not worth your time" is just wrong.  Using a meter is one of the ways a professional sets up equipment.  But yes, to do it correctly assumes the installer knows how to use a meter properly and understands electrical theory.  It is NOT a simple step-by-step cookbook answer suitable for a beginner, but in most cases it is the BEST answer.
Support the12volt.com
casedeez 
Copper - Posts: 160
Copper spacespace
Joined: April 21, 2004
Location: United States
Posted: May 16, 2004 at 1:49 PM / IP Logged  

I realize your a professional and using a multimeter for yourself is not a problem what so ever. However for this post I believe it is suitable to say "its really not worth your time:" Reason, as you stated it is not a simple step by step process. Its not something a "beginner" should mess with. I am trying to be helpful and contribute to this forum on topics I think I know at least somewhat or have dealt with. It appears xTimx is in the same relative spot as me when it comes to using a multimeter for setting  gains. Since that is the case does it not seem appropriate to say MY opinion. On the other hand when I spoke to another professinal he stated simply that setting gains with a multimeter and being accurate is nearly impossible due to the fact that at different freqeuncies the amplifier will send different voltages and in turn your have different impedance levels. In other words you can set gains according to the meter at one specific frequency, however at different frequencies the amp will produce different, unmatched voltages. As a side note id like to think of myself as more of an amateur rather than a beginner. I dont play with stereos as a proffesional but it is more of a hobby. I have been playing with stereos since I was about 15. Im 22 now. 7 years may not be a lifetime, and I may not have went to school for it, but it certainly doesnt mean I am a beginner. (a novice, or one who is just beginning)

By no means am I trying to be sarcastic, degrading, or rude. I am simply stating my opinion and my thoughts in regards to the preceding post.

DYohn, I dont want to be looked at as a fool who shouldnt be playing with this stuff, rather a person trying to obtain knowledge. If you feel as though the process escaped me, tell me where I went wrong.

xTimx 
Copper - Posts: 354
Copper spacespace
Joined: September 13, 2002
Location: Canada
Posted: May 16, 2004 at 2:10 PM / IP Logged  
well your both right on your terms. and casedeez, your opinion should go for everyone else on the site too! anyways. back to my Q's
on the JL audio tutorial there is a flash movie that tells you how to set up your gains on your amp using a multimeter, preferrably using a digital one, in which i DO have one. there is also a chart for getting the amp volts at diff ohms, i think i already have my 4 channel amp for volts and that is 17.3 v's for the fronts and rears but i cant quit seem to get my sub amp. keep in mind its wired in 6ohms. and it is also bridged.
xTimx
DYohn 
Moderator - Posts: 10,741
Moderator spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: April 22, 2003
Location: Arizona, United States
Posted: May 16, 2004 at 2:19 PM / IP Logged  

casedeez, I stand by my comments 100%, and judging from the problems you had trying to use a multimeter I also stand by my evaluation that you are indeed a beginner in this area.  This is not a slam, it is an observation.  Please refer to my earlier post in this thread as it may help you in the future as well:

DYohn wrote:
  I use a Fluke model 70 or 77 for basic ohms and voltage tests and a model 85 for more sophisticated tests.  I am reluctant to try and describe a "how to", but you could start with a web-based tutorial like this one: http://www.multimeterwarehouse.com/usingamultimeter.htm

The best suggestion I could probably give is for you to seek out a basic electricity or introduction to electronics course at a local community college or high school.

Please look at the tutorial I referenced.  ANYONE who thinks that learning how to do things the correct way is "not worth the time" is, in my opinion, just being lazy.

Support the12volt.com
DYohn 
Moderator - Posts: 10,741
Moderator spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: April 22, 2003
Location: Arizona, United States
Posted: May 16, 2004 at 3:27 PM / IP Logged  
Timx, to answer your question, Ohm's law says that voltage = the square root of power times resistance.  So, multiply the RMS wattage of your amplifer times the net resistance of your subs (6 ohms.)  Then take the square root of this number, and you end up with the voltage required to produce the RMS power.  For example, if your amplifier produces 300 watts RMS, then 300X6=1800.  Square root of 1800=42.42 volts.  To set up your amp, turn the gain all the way down, disconnect your speakers, set your head to it's maximum non-clipping output (usually around 75 to 80% volume), play a tone (for subs, 50 to 80 Hz,) connect your AC volt meter to the amp (using the same connections the speakers will use) and slowly increase the input gain until the voltage reads 42.42 (or 42) volts.  This will set your amp to produce max output when the head is sending it max input.
Support the12volt.com
Page of 2

  Printable version Printable version Post ReplyPost New Topic
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

  •  
Search the12volt.com
Follow the12volt.com Follow the12volt.com on Facebook
Wednesday, May 8, 2024 • Copyright © 1999-2024 the12volt.com, All Rights Reserved Privacy Policy & Use of Cookies
Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

Secured by Sectigo
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
Support the12volt.com
Top
the12volt.com spacer
the12volt.com spacer