| Author |
Thread: Clamp meter? |
    
Gold Member Username: Snarl2004
Digital Design 9515,
Massive Audi...
Post Number: 2373
Registered: Dec-06
|
| Posted on Monday, May 12, 2008 - 08:35 pm: |
|
Can a clamp meter tell you how many rms your amp is putting out? |
|
Relevant Product Info
|
|
Gold Member Username: Johnfiac
A-ToWn,
Bangn aint easy
....when u g...
Post Number: 4049
Registered: Mar-06
|
| Posted on Monday, May 12, 2008 - 08:36 pm: |
|
need a dmm to... |
Gold Member Username: Johnfiac
A-ToWn,
Bangn aint easy
....when u g...
Post Number: 4050
Registered: Mar-06
|
| Posted on Monday, May 12, 2008 - 08:38 pm: |
|
with both of these you can find out how much power your pulling and how much you get back in return; test incoming and outgoing power  effientcy FTW  |
Gold Member Username: Snarl2004
Digital Design 9515,
Massive Audi...
Post Number: 2374
Registered: Dec-06
|
| Posted on Monday, May 12, 2008 - 08:41 pm: |
|
so how exactly do you do it? |
Gold Member Username: Southernrebel
Monroe,
Louisiana
2 DD3515s, 2...
Post Number: 6385
Registered: Mar-04
|
| Posted on Monday, May 12, 2008 - 09:26 pm: |
|
You test both AC current and AC voltage coming from the amp at a given freq.
Voltage x Amps = Watts
You will need True RMS DMM's and Clamps. |
Gold Member Username: Snarl2004
Digital Design 9515,
Massive Audi...
Post Number: 2375
Registered: Dec-06
|
| Posted on Monday, May 12, 2008 - 09:40 pm: |
|
1)you do current with the clamp meter and voltage with a dmm correct?
2)do you do it with th sub still plugged into the amp?
3)any test tone or a particular one?
4)does the current you get = the amps? |
Gold Member Username: Southernrebel
Monroe,
Louisiana
2 DD3515s, 2...
Post Number: 6386
Registered: Mar-04
|
| Posted on Monday, May 12, 2008 - 09:49 pm: |
|
1-yes
2-no, you have to have the sub hooked up.
3-I usually use the freq I peak at for SPL.
4-yes |
Gold Member Username: Nd4spd18
Northwest PA
Post Number: 7445
Registered: Jul-06
|
| Posted on Thursday, May 15, 2008 - 12:14 am: |
|
You can't, CAN NOT, as in NOT possible, to measure amplifier output without
1) Oscilloscope
2) Very high current resistors
3) DMM
You can not do it without a scope. You can not use speakers in place of the resistors. Now, if you want to measure amplifier efficiency, then you need a clamp meter capable of measuring DC amperage (i.e. one that has a Hall effect sensor in it), in addition to all of the above items. |
Gold Member Username: Southernrebel
Monroe,
Louisiana
2 DD3515s, 2...
Post Number: 6391
Registered: Mar-04
|
| Posted on Thursday, May 15, 2008 - 03:48 pm: |
|
MS,
You can't test them based on the nominal load, but you can on the apparent load. (Box rise)
The #'s will not be exact, but you can get pretty close. You have to get Current and voltage, that way you can determine AC impedance and power. Different subs will react differently to the box, so you will not get the same power to different subs. The different sub's inductance values are different.
And yes, I would suggest the use of an O-scope (actually I do).
Here is alil test session I did last weekend:
http://forum.ecoustics.com/bbs/messages/4/483457.html |
|
|
Gold Member Username: Hdubb
Team Revolution
Post Number: 3674
Registered: Nov-04
|
| Posted on Thursday, May 15, 2008 - 08:24 pm: |
|
thats good info canaan, and its easy to understand |
Gold Member Username: Johnfiac
A-ToWn,
Bangn aint easy
....when u g...
Post Number: 4057
Registered: Mar-06
|
| Posted on Thursday, May 15, 2008 - 09:42 pm: |
|
MS thats not easy to come by tho the ossiliscope i can understand to make sure ur not clipping and all but like Canaan said its just a close number if u do it right u usually within +/-100RMS range of the actual output not considering box rise and all.. i dont really think resistors are needed for testing when u use the subs tho as its pointless becuz ur subs wont ever see that power.. only the resistors. testing with the subs is much better so u kno what they see |
Gold Member Username: Johnfiac
A-ToWn,
Bangn aint easy
....when u g...
Post Number: 4058
Registered: Mar-06
|
| Posted on Thursday, May 15, 2008 - 09:43 pm: |
|
osciliscope would still be great for tuning amps to the max b4 clipping tho.. |
Gold Member Username: Nd4spd18
Northwest PA
Post Number: 7490
Registered: Jul-06
|
| Posted on Friday, May 16, 2008 - 12:10 am: |
|
" Different subs will react differently to the box, so you will not get the same power to different subs "
Thats is the problem. Your testing will be accurate for that specific speaker and that specific box, and ONLY at the specific frequency you played. IMO not very useful for daily system which will play music.
With a resistive load (speakers are reactive) you can measure maximum amplifier output across the entire frequency spectrum. |
