DSMKilla Posted August 19, 2014 Report Share Posted August 19, 2014 I'm waiting for my SMD-AMM1 to be delivered in a few days. So today I got bored and decided to do some preliminary testing on my Kicker amp using a DMM and Amp Clamp. Here's what I'm working with...ComponentsPioneer AVIC-X920BT HeadunitKicker CX600.1 Amplifier300W x 1 RMS @ 4 ohmsKicker 40CWR102 Subwoofer600W RMS2ohm DVC wired in Series = 4ohmsBox is an EFX SE10CC 10" Sealed Box 0.75 cu.ft.Testing EquipmentFluke 117 True RMS DMM (To Measure AC Volts)Klein CL2000 True RMS DMM/Clamp (To Measure AC Amps)SMD-DD1 (To dial in the Gain)I've got door speakers wired to the deck and the deck clips at 34 according to the DD1. I've got the amp hooked up to the sub pre-amp outputs on the deck. My gain on the amp is dialed in with the volume knob at 34. So with my deck volume at 34 amp gain dialed in using a 40Hz -5dB test tone and my DD1 both DMM's zerod and set to MAX mode I burp it and let it play for like 10 seconds and this is what I get....33.53V x 2.35amps = 78.80vaSo I know that watts can't be accurately measured without the PF, I know this, however, every test I've seen people do with a clamp has always netted a VA that comes within ~15-20% of the amps actual watts output. So how the hell am I only getting 78.80va on a 300W amp??? The certificate that came in the box with the amp shows it was bench tested and put out 337watts. I mean if I would have tested and came out with something that was right around ~250watts I would have been satisfied. But 78.80?? So I'm guessing SOMETHING has to be off or I'm doing something wrong. I have even verified the measurements with two other meters and the results are always about the same. So I know it's not faulty test equipment.Any ideas? Link to comment Share on other sites More sharing options...
Ritch40 Posted August 19, 2014 Report Share Posted August 19, 2014 what is your subsonic filter set at? I just made some changes to my system tonight and clamped it again. what i see in your pics reminds me of what i saw in the area where the subsonic filter was working. Did you by chance perform the test at other frequencies? Link to comment Share on other sites More sharing options...
DSMKilla Posted August 19, 2014 Author Report Share Posted August 19, 2014 This particular amp doesn't have a subsonic filter. I've got the Low-Pass Freq set to max (200Hz) and I've got the deck set to 100Hz. I did test other frequencies 50Hz, 60Hz, and 80Hz. However, I didn't see any substantial change. I think the highest I was able to get up to was like 106VA which was with either the 50Hz or 60Hz, I can't remember exactly since I didn't really take note of them since like I said they wasn't any kinda drastic change. I was at least expecting to see something around 12amps but the max I can get is around 5amps. At 5 amps I would expect to be seeing something a lot higher on my volts but I'm not. Link to comment Share on other sites More sharing options...
EDH Posted August 19, 2014 Report Share Posted August 19, 2014 Remember impedance rise? With some simple math you will see that your amplifier is doing 78.8VA @14ohm. 33.53/2.35=14.26809 Current setup DD Z318 Extra Stiff, Kevlar cone, Double top plate x2 Banda Viking 10k x2 5 Banks of Maxwell 2.85v 3400F caps Build log Termpro Profile Link to comment Share on other sites More sharing options...
DSMKilla Posted August 19, 2014 Author Report Share Posted August 19, 2014 Right, yeah I was thinking about that earlier, I'm glad you brought it up. So why is my load only 14ohms rather than 4ohms? ----- EDIT ----- Ok I just researched it a little. I don't think this is related to impedance/box rise. I will test again tomorrow with the subwoofer OUT of the box and see what happens. Link to comment Share on other sites More sharing options...
EDH Posted August 19, 2014 Report Share Posted August 19, 2014 You will still see impedance rise as the cone moves. It dosent matter if the sub is in the box or free air. But i think you will see less rise when the sub is free air. Current setup DD Z318 Extra Stiff, Kevlar cone, Double top plate x2 Banda Viking 10k x2 5 Banks of Maxwell 2.85v 3400F caps Build log Termpro Profile Link to comment Share on other sites More sharing options...
Nightshade Posted August 19, 2014 Report Share Posted August 19, 2014 The unit that is produced when multiplying voltage and amps together is watts not VA. Which means you are making 78 watts not 78VA. It sounds ignorant saying it the way you are. 2013 VW Jetta GLI 2.0 Turbo 1 Sundown Audio SCV2000 1 Sundown Audio X15 V2 1 XS Power D3100 Audio Control LC6i Stock Deck 146.4 sealed on the dash at 37hz 2001 Focus ZX3: RETIRED Team Sundown Audio, Team XS Power, 2 time NSPL Car 3601-Up Champion, 2 time NSPL Car Hardcore ChampionHighest NSPL Scores to date:154.3db on the dash sealed at 46hz, 156.2db in the kick at 46hz155.2db unofficial on dash at 43hz Link to comment Share on other sites More sharing options...
Wicks Posted August 19, 2014 Report Share Posted August 19, 2014 ^^^ Sorry, he is using the correct method which is nice to see actually. Impedance will change with frequency and 14ohms would not be out of the question but you should see more fluctuation then that. Have you verified your nominal impedance is around 4ohms? Don't have any damaged voice coils? This post sent with 100% recycled electrons. 2004 BMW M3Mechman 280A 2 - XS Power XP30001 - XS Power D375 500F of Maxwell SuperCaps (soon to be 1000F) iPadMini2Dash mounted O-scopeAudison bitOne (Remote DRC MP) Highs Amp - PPI Art A404 Hertz HSK130 (HSK165 waiting...) DC Audio DC9.0K 2- DC Audio XL12m2LEGAL - 147.3dB @ 41Hz OUTLAW - 150.2dB @ 45Hz OUTLAW - 145.7dB @ 30Hz JUNE 2014 SOTM WINNER 2014 COLORADO PEOPLE'S CHOICE WINNER SOTM BUILD:http://www.stevemeadedesigns.com/board/topic/141656-wicks-e46-m3-build-bass-turbo-button-and-a-big-new-addition/page-68#entry2802026 Link to comment Share on other sites More sharing options...
Nightshade Posted August 19, 2014 Report Share Posted August 19, 2014 ^^^ Sorry, he is using the correct method which is nice to see actually. Impedance will change with frequency and 14ohms would not be out of the question but you should see more fluctuation then that. Have you verified your nominal impedance is around 4ohms? Don't have any damaged voice coils? No one said he wasn't using the correct method. I said that when you multiply amperage by voltage the resulted unit is watts no VA. I don't know what you are referring to but it sounds ignorant saying VA when the result is watts. 2013 VW Jetta GLI 2.0 Turbo 1 Sundown Audio SCV2000 1 Sundown Audio X15 V2 1 XS Power D3100 Audio Control LC6i Stock Deck 146.4 sealed on the dash at 37hz 2001 Focus ZX3: RETIRED Team Sundown Audio, Team XS Power, 2 time NSPL Car 3601-Up Champion, 2 time NSPL Car Hardcore ChampionHighest NSPL Scores to date:154.3db on the dash sealed at 46hz, 156.2db in the kick at 46hz155.2db unofficial on dash at 43hz Link to comment Share on other sites More sharing options...
Guest Posted August 19, 2014 Report Share Posted August 19, 2014 Right, yeah I was thinking about that earlier, I'm glad you brought it up. So why is my load only 14ohms rather than 4ohms? ----- EDIT ----- Ok I just researched it a little. I don't think this is related to impedance/box rise. I will test again tomorrow with the subwoofer OUT of the box and see what happens. yes it is impedance rise. hook an ohm meter up to the speaker terminals and play music. you'll see the number jump around like crazy. you dont even have to play music. just drop a penny on the cone and watch the ohm meter move. Link to comment Share on other sites More sharing options...
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