How to clamp an amplifier - Car Audio Classifieds!
Car Audio Classifieds!  

Go Back   Car Audio Classifieds! > Car Audio Help & Discussion > Tutorials & Quick References

Tutorials & Quick References This section is for how-to's and quick references for car audio.


Notices

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 05-19-2011, 10:49 PM
oslouie's Avatar
Elite Member
 
Activity Longevity
0/20 17/20
Today Posts
0/11 sssss5073
Location: minnesota
Thanks: 41
Thanked 278 Times in 211 Posts
iTrader: (69)
Feedback Score: 69 reviews
Default How to clamp an amplifier

Don't give me all the credit as this has been copied and pasted.

You'll need a good digital multimeter.

you'll need a good digital clamp meter.

a pen and paper

and a buddy.


you hook up your amp, sub, etc... get it all connected.

then you clamp the clamp meter on the positive speaker wire. ONLY on the positive wire.. and clamp it as close to the amp as possible. (i clamp about 2" from the amp terminal)

then you connect your dmm to the positive and negative speaker wires. pos to pos and neg to neg.

set your clamp meter to 100 or 200 ac amp range. whichever is the lowest your clamp offers.

set your dmm to 200 ac volts.

now, get ready to play some test tones...

as you play your tones.. you want to play them long enough for the meters to stabilize thier readings.

you and your buddy should each be in charge of reading one meter. because it can be difficult to try and remember the peak you saw on each of them. (if you have a higher dollar clamp with PEAK hold (not data hold) then you can set it to hold the peak amperage it sees, then you only need to remember the ac volts)

after each tone, you should write down the peak ac amps and the peak ac volts.

now is the fun part.. the math...

acvolts X acamps = real watts used (this is the actual amount of watts your amp produced at that frequency and volume control)

acvolts / acamps = reactive ohm load (this is your REAL ohm load when playing that frequency.)


so.. lets look at some real world examples....


joe dirt has a 4000 watt amp.

it's rated for :
1000 @ 4-Ohms
2000 @ 2-Ohms
4000 @ 1-Ohm

he has read that it only does around 3000 watts @ 1ohm, on forums (mostly from people who have no clue and have never used or tested that amp) so everyone says that amp is waaaay overrated, by at least 1000 watts.

so, joe goes and gets one. he hooks it up in his car on his super duper fancy beefy competition sub with giant motor and super cool dustcap, this is a competition sub so it has dual 1 ohm coils, so he wires the coils together and hooks it up to the amp at 1/2 ohm because at 1/2 ohm it should put out superunbelievableginormous amounts of power.

he hooks up his clamp meter and his dmm.

he gets out his pad and paper, and starts going through his bass cd's test tones, playing each tone looking to find out what his peak frequency is, and then playing that peak frequency at every volume level until he thinks its distorting so he stops there.

at the end of it all, he looks to see which volume level and frequency gave the msot power..

low and behold, he's in for a few surprises.

first of all, he thought his peak frequency was 35 hz, because thats what his enclosure is built to.. but hediscovers that with in car gain.. his peak is actually 53 hz .

then he discovers that even though his sub is connected to his amp at 1/2 ohm.. he's actually waaaay above that.

he figures it out with the math.

we'll say that his peak frequency gave him the following readings...


71.4 ac volts

31.8 ac amps

so...

71.4v X 31.8a = 2270 real watts

so dangit.. they were right on those forums.. his 3000 watt amp hooked up at 1/2 ohm only does 2270 watts.

man, now he hates that manufacturer and slams them on every forum because his amp is overrated by almost twice as much...

but....

had he done the REST of the math....

71.4v / 31.8a = 2.24 ohms

he would have realized that his sub, while hooked up at 1/2 ohm.. was actually playing at 2.24 ohms because he has such a huge box rise.

so now... is his amp still overrated?

it claims to do 2000 at 2 ohms... and he is doing 2270 at 2.24 ohms.

looks to me like his amp is actually UNDERated.. and worthy of some praise instead of being slammed all the time.


so, joe takes this newfound knowledge and builds himself a new enclosure, he has no idea if it will be better or worse, but hes prepared to find out...

his new box, with the same amp and the same sub, gives him the following result....

70.1 ac volts

59.5 ac amps

so...

70.1v X 59.5a = 4170.95 watts

and

70.1v / 59.5a = 1.17 ohms

holy moley joe is making 4170.95 watts @ 1.17 ohms from an amp thats only rated for 4000w at 1 ohm !!! looks to me like his amp is UNDERrated even more than he thought it was.

and look at that, he went from 2.24 ohms down to 1.17 ohms just from building a more effecient box.

AND... the best part.. he gained 1900.95 REAL watts... and didnt buy any new equipment to do it... all he did was build a new box.

Now joe will go out onto forums with REAL WORLD numbers, and actual tests that he hs done, and instead of jumping on a hate bashing bandwagon, with a bunch of people that dont have real world experience wit hthat particular amplifier, and he'l lgive them real results and a real opinion, based on real experience, not based on something he read on a forum that was posted from peole without said real experience.


and this is the reason that people that dont know what they are doing tend to claim that certain amps are overrated or underrated, when in fact they have never clamped the amp to see what thier box rise, ohm load, or power was.


and of course.. lets not forget that joe saw these results on a burp, with his peak frequency, ie: the most perfect note for his car, on the most perfect volume for his car.

but can you guess what happens when he pops in a music cd.... you got it.. the music is dynamic. the volumes and the notes are ever changing. so the reactive load is going to change CONSTANTLY, as is the overall power output.
Reply With Quote Quick reply to this message
The Following 21 Users Say Thank You to oslouie For This Useful Post:
727Designs (07-24-2011), BanginGMC (06-13-2011), bgrapids (03-01-2012), cf2004 (08-16-2011), chrishova (07-25-2011), ControlFreak (09-21-2013), Dirtbikerrob (07-24-2011), Dirtrider4eva (07-24-2011), getonerd (08-02-2011), Homernuts (07-24-2011), imlouder (06-18-2011), KNOTDUDE (03-26-2012), LEN671 (05-20-2011), [email protected] (05-19-2011), LowBassOver (07-30-2011), MitchtheTwitch4 (01-20-2013), More spl (05-19-2011), naughtyca (09-19-2012), Positive P (07-20-2011), quaddropper (07-24-2011), Spudy1 (07-16-2012)
Sponsored Links
Advertisement
 
  #2  
Old 07-24-2011, 07:06 PM
Burkem_10's Avatar
CACO Member
 
Activity Longevity
0/20 15/20
Today Posts
0/11 ssssss469
Location: Kalamazoo, MI
Thanks: 68
Thanked 30 Times in 24 Posts
iTrader: (7)
Feedback Score: 7 reviews
Default

So how does joe dirt go about making a more efficient box?
Reply With Quote Quick reply to this message
  #3  
Old 07-24-2011, 07:32 PM
me neither
 
Activity Longevity
0/20 19/20
Today Posts
0/11 ssssss894
Location: In front of my monitor
Age: 44
Thanks: 16
Thanked 6 Times in 6 Posts
iTrader: (12)
Feedback Score: 12 reviews
Default

How many test tones and what freqs.

How do you arrive at the peak freq.??

tim
__________________
Tim Strong

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

X-Box Live gamertag: quad drpr

"Once I have made a hasty, uninformed decision it cannot be changed." -Doofensmirtz

REFS:
SUBW123, splvictim20, ellocojorge, slamnride, Hellbound Train, Jstang2003, Basebalz13, CrownVic97, EpicenterDesigns, Extremechevyman67, spy, xseveredveganx
Reply With Quote Quick reply to this message
 
  #4  
Old 07-24-2011, 07:49 PM
DC98hoe's Avatar
Doing 156s below the seat
 
Activity Longevity
0/20 17/20
Today Posts
0/11 sssss1372
Location: stockton ca
Thanks: 92
Thanked 111 Times in 93 Posts
iTrader: (1)
Feedback Score: 1 reviews
Default

make sure you use a true rms clamp meter otherwise you will get a false ready. pretty sure the regular ones only read a/c voltage at 60hz
__________________
98 tahoe 4-team ascendant 18s ,2-Flatline 9.5s 18 v --singer 320 hairpins-4th order 160dbs
Reply With Quote Quick reply to this message
  #5  
Old 07-24-2011, 07:53 PM
Audio Enthusiast
 
Activity Longevity
0/20 15/20
Today Posts
0/11 ssssss733
Location: Milwaukee
Thanks: 34
Thanked 18 Times in 14 Posts
iTrader: (4)
Feedback Score: 4 reviews
Default

Quote:
Originally Posted by Burkem_10 View Post
So how does joe dirt go about making a more efficient box?
X2
Reply With Quote Quick reply to this message
  #6  
Old 07-24-2011, 07:55 PM
Audio Enthusiast
 
Activity Longevity
0/20 15/20
Today Posts
0/11 ssssss733
Location: Milwaukee
Thanks: 34
Thanked 18 Times in 14 Posts
iTrader: (4)
Feedback Score: 4 reviews
Default

and what brand/ price range would a decent clamp meter fall in to.
Reply With Quote Quick reply to this message
  #7  
Old 07-24-2011, 07:59 PM
SPL Distribution Owner
 
Activity Longevity
0/20 18/20
Today Posts
0/11 sssss2983
Location: Louisville, KY
Thanks: 54
Thanked 467 Times in 352 Posts
iTrader: (0)
Feedback Score: 0 reviews
Default

make sure to NEVER use peak hold on either meter!
Waiting for their readings to stabilize is crucial too.

This should only take between 0.1-2sec.
Reply With Quote Quick reply to this message
  #8  
Old 07-24-2011, 08:12 PM
CACO Member
 
Activity Longevity
0/20 15/20
Today Posts
0/11 ssssss172
Location: Bama
Thanks: 6
Thanked 2 Times in 2 Posts
iTrader: (6)
Feedback Score: 6 reviews
Default

Good read
Reply With Quote Quick reply to this message
  #9  
Old 07-24-2011, 08:46 PM
Novicaine's Avatar
CACO Late Night Crew
 
Activity Longevity
0/20 17/20
Today Posts
0/11 sssss6135
Location: Porterville, CA
Thanks: 728
Thanked 192 Times in 161 Posts
iTrader: (27)
Feedback Score: 27 reviews
Default

Didn't steve write this at DD forum??
Reply With Quote Quick reply to this message
  #10  
Old 07-25-2011, 06:00 AM
CACO Member
 
Activity Longevity
0/20 15/20
Today Posts
0/11 ssssss172
Location: Bama
Thanks: 6
Thanked 2 Times in 2 Posts
iTrader: (6)
Feedback Score: 6 reviews
Default

Quote:
Originally Posted by Huricain3 View Post
Didn't steve write this at DD forum??
I've seen this same post on multiple forums, but i couldn't tell you where or who it originated from.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Car Audio Classifieds! forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Location
Where you live
Level of Car Audio Knowledge
What's your level of car audio?

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Clamp Testing???? [email protected] General Car Audio Discussion & Questions 54 05-20-2011 07:38 PM
SAX-100.4d Clamp? thisistiny (Sundown Audio) 6 12-02-2010 08:29 AM
clamp more then 2 amps? noknok General Car Audio Discussion & Questions 3 11-05-2010 03:46 AM
Clamp meter TurdFergueson2 General Car Audio Discussion & Questions 2 06-07-2010 01:25 PM
Clamp Meter mazda6i07 General Car Audio Discussion & Questions 11 07-09-2009 07:38 AM

» Amps
A/d/s/
Advent
Alphasonik
Alpine
American Bass
ARC Audio
Atomic
Audio Art
Audio Gods
Audiobahn
Audiocontrol
Audiopipe
Audison
Aura
Autotek
Avionixx
Bazooka
Beyma
Blaupunkt
Boss
Boston Acoustics
Bravox
Cadence
Cascade (CAE)
CDT Audio
Cerwin Vega
Clarion
Clif Designs
Concept
Coustic
Critical Mass
Crossfire
Crunch
DB Drive
DC Audio
DC Power
DEI
Denon
Diabolo
Diamond
Digital Designs
Directed
DLS
Dual
DYnamat
Dynaudio
Earthquake
Eclipse
Elemental Designs
ESX
Eton
Farenheit
Fi Car Audio
Fix My Speaker
Focal
Fusion
Genesis
Ground Zero
Hafler
Helix
Hertz
Hifonics
Hushmat
Image Dynamics
Infinity
Interfire
JBL
Jensen
JL Audio
JVC
Kenwood
Kicker
Knu Konceptz
Kole Audio
Kove Audio
Lanzar
Lightning Audio
Linear Power
MA Audio
Magnat
Marantz
Massive Audio
MB Quart
McIntosh
Memphis
Metra
MMATS
Mobile Authority
Morel
MTX
Nakamichi
Niche Audio
O2 Audio
Ohio Generator
Optima
Orion
Oxygen Audio
OZ Audio
PG Audio
Phase Linear
Phoenix Gold
Pioneer
Polk
Power Acoustik
Powerbass
Powermaster
Precision Power
Profile
Pyle
Pyramid
RadioShack
Rainbow
Rampage
RE AUdio
Rockford Fosgate
Scanspeak
Scosche
Seas
Sony
soundstream
Sparkomatic
SPL Dynamics
Stinger
Sundown Audio
Swiss Audio
Targa
TC Sounds
TREO Engineering
TRU
Tsunami
Ultimate
US Acoustics
US Amps
Velodyne
Vifa
Viper
Visonik
Xtant
Zapco
Zed Audio
Powered by vBadvanced CMPS v3.2.3
Links
Amp Guts
amplifier, amp guts, ampguts, car audio classifieds, speakers and subs for sale with listings of 12 volt sound systems. Security systems for sale for aftermarket car audio equipment with amplifier and amps for sale
Car Audio Forum
car audio forum, moble audio, car stereo, wholesale car audio, 12 volt, with, amplifier, amp, subwoofer, sound quality, buy car audio, and sell automotive stereo systems for cars
Car Audio Sound Quality Forum
Sound QUality science based car audio forum, amplifier, subs and speaker design, fabrication help, sound systems forum, aftermarket car audio website for sound quality.
Car Stereo Forum
DIYMA car audio stereo forum for 12 volt car audio subwoofer and amplifier systems that have sound quality with wholesale car audio products.


All times are GMT -5. The time now is 06:42 PM.


Powered by vBulletin
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.6.0
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.