moh.vze.com
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Posts posted by moh.vze.com
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Are you using your scope just to read voltage? Or are you using it for that AND to see clipping as well? Thought thats why you had a scope?
Only power that matter is clean power..... no?
Or am i lost?
Well I originally used the oscope for setting the gain without the speaker wires hooked in and it had a clean curve. But when I hook up the speaker wires to the amp and play the tone at that exact same volume, I'm getting dirty power.
That's where I'm a bit confused. People say to set the gains without the subs hooked up. Maybe someone can chime in on this.
By the way, I don't bump my music with the voltage going below 12.5V.
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I couldn't post all of the media links in the first post so here's Clamp run 5
Here is a video of the resistance reading for the subs nominal load:
40 Hz @0dB test tone was used on all of the tests.
I would like to note that my box is tuned to 30hz and I have the SSF set to 25Hz.
Was I suppose to burp at different frequencies? (Ie: Burp at 30hz, 35hz, 40hz, 45hz, and 50hz)
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Can you guys lock this thread please?
I've created a new one here:
I created a new thread because the results in this video were not accurate due to a faulty function on the clamp meter. A new thread will help keep everything clear and organized.
Thanks!
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Alright. I've recorded 5 different clamp tests. The second video uses the Pmax function on the clamp meter and the rest doesn't use that function for more accurate results.
40Hz test tone @ 0dB was used.
Here is a video showing you guys the setup.
What I've done differently this time was plugged my leads into the amplifier speaker terminals.
The final ohm resistance actually read 1.1ohms (not 0.7 ohms like I had thought).
DC5k Clamp Test - Run 1:
Clamp Meter Max AC Current: 61.4A
Oscope Max AC Voltage: 66.8V
DMM Max AC Voltage: 63.6V
Results:
Equation: AC Current * Ac Voltage:
Using Oscope Voltage:
61.4A*66.8V = ~4101Watts
Using DMM Voltage:
61.4A*63.6V = ~3905Watts
DC5k Clamp Test - Run 2 - Used Pmax Function:
Note: Using Pmax function on Clamp Meter
Clamp Meter Max AC Current: 76.6A
Oscope Max AC Voltage: 69.3V
DMM Max AC Voltage: 65.8V
Results:
Power = Current * Voltage
Power = 76.6A* 69.3V = 5308 Watts (Using the oscope voltage reading)
Power = 76.6A * 65.8V = 5040 Watts (Using DMM Voltage Reading)
DC5K Amplifier Clamp Test - Run3
Note: I rolled the volume up and down a bit. Might have skewed the results.
Clamp Meter Max AC Current: 60.6A
Oscope Max AC Voltage: 66.8V
DMM Max AC Voltage: 63.3V
Results:
POwer = 60.6A * 66.8V = 4048 Watts (Using oscope volt reading)
Power = 60.6A * 63.3V = 3836 Watts (Using DMM volt reading)
DC5K Amplifier Clamp Test - Run4
Clamp Meter Max AC Current: 53.6A
Oscope Max AC Voltage: 69.3V
DMM Max AC Voltage: N/A
Results:
Power = 53.6A * 69.3V = 3714 Watts
DC5K Amplifier Clamp Test - Run5
Video: See Post #3
Note: This was my final Clamp Run
Clamp Meter Max AC Current: 59.3A
Oscope Max AC Voltage: 68.1V
DMM Max AC Voltage: 64.2V
Results:
Power = 59.3A * 68.1V = 3741 Watts
Power = 59.3A * 64.2V = 3809 Watts
Any thoughts? I was hoping it would be more power than this. Would it make a difference if I go back and reset my gains to the point of clipping and go down a little? I left a pretty big gap when I was setting my gains.
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I've recorded new videos. I'm going to post them here after I've uploaded. Apparently the Pmax function on my clamp meter is indeed not working correctly; as a result, I will be driving to Sears today to exchange it for a different one.
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So when I clamp the amp do I want my DC Voltage to be above 12.5V? Someone above was asking if I clipped it during the clamp. Would it affect the results if the DC Voltage drops below 12V?
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Just shot these real quick tonight while I was testing 2 of my Level 6 15s free air.
acA- 5.45a
acV- 38.1v
= 207.645w @ 6.99 ohms
This was done with the 5k turned up just under half volume.
This test was not done to show power output, but to show how to properly clamp an amplifier.
Thanks. I will check this out tomorrow.
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Ah power factors and phase angels. I remember solving homework problems like those in my electronic classes but never understood what those numbers ment until now.
Multiplying by that power factor number gives the rms?
Anyways, back to using the oscope, I don't think my Velleman can give me a current graph and the voltage graph like that lunchbox scope.
So should I just clamp it to the point of clipping even if I have to stop the volume knob 2 volume notches before my max tuned?
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I will see if I can get my hands on a friends 5k tomorrow and hook it up to my truck and burp it a few times and video everything.
Thanks.
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Use an o-scope
Check your jumper leads, its not uncommon that they can have poor connections internally (not where the alligator end grabs but where the alligator end is crimped inside the plastic sheathing).
I have a Velleman Oscope HSP10.
I'll hook that up on my next test tomorrow after I charge the batteries over night.
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Interesting. How can we figure out what is going wrong? My DC voltage does go from ~14.3V to ~11.4V is this bad for clamp testing?
I am wondering if my AC Current Pmax on the clamp meter is messed up.
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these results dont matter anyway because according to tony your doing it all wrong.
How can I do this properly?
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I have never done a clamp test where the AC Voltage was lower than the Amperage.
Even in my first clamp run with the bassknob not all the way up, the ac voltage was lower than the ac amperage. And during that run, I didn't go over my max tuned volume.
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You sure you weren't clipping during the test?
I probably was clipping during the test because I accidentally went to volume 28 instead of my max tuned 27 at one point. Should I redo the test without going over my max volume?
What hz tone was used for the test?
40Hz @0dB (the test tone I used to set my gains with. There was no clipping when I set the gains without a load. Should I connect the oscope to the speaker wires while running the clamp test to see if it's clipping?
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I am clueless with this one. I have never done a clamp test where the AC Voltage was lower than the Amperage.
Since I cant see where the meters are hooked in, I just want to make sure that the DMM went into the positive and negative speaker wires and the clamp went around the positive speaker wire.
The Positive lead of the DMM was connected to a jumper wire that is connected to the positive speaker input into the DC5K
Vice-versa for the Negative lead to the negative speaker wire input.
Pics of the jumper cable I used:
The clamp meter was clamped around the positive speaker wire.
Should I touch the two jumper wire ends together to see if there were any resistance with the jumper cables?
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Touch the leads together on your multi meter. If it reads anything other than zero, subtract that from what you measure
I did it last night and it read 0.1ohms
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Here is a video of my first DC 5K clamp run. This one I forgot to turn the bassknob all the way up so the output power will be lower.
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It's puzzling... It means you have zero box rise.
Did you measure .8 ohms with your DMM?
What's weird is when I measure closest to the DC5K speaker inputs it oscillates from 0.8ohms to 0.9ohms
When I measure close to my speaker box output terminals it oscillates between 0.7ohms to 0.8ohms.
I will make a video of the measurements when I get home later.
Is 0 box rise even possible? All I know is my DC Audio system sounds like crap with the sub box that I have now compared to my old sub setup.
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At .77 ohms reactive. Damn son, what are you wired to?
Any idea what your DC voltage drop was?
DC Voltage went down to 11.5
Nominal resistance with the subs inside the box is 0.8ohms.
0.77 reactive bad or good?
Actually the DC Voltage is probably 11.3V because I haven't recalibrate the Stinger Meter yet. Stinger Meter is .2V too high than what my DMM reads.
When we do this we only care for the max results right? Because it looks like the AC Voltage was more steady around 63V.
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Update: I just rewatch the video and I saw 66.2 for the max voltage.
So,
66.2V*85.8A = 5680Watts!
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Update: These videos are not accurate because the Pmax function on my clamp meter was not working properly. See new thread here:
_______ (I will post thread link later once I've uploaded all of the clamp runs).
The only mistake I made during the clamp test was I went 1 volume over the max tuned volume on my headunit. I don't think this will effect the results except the fact that I probably sent dirty power for that 1/2 second. I rolled the volume up and down a little bit at one point so that is why you will see the voltage go up and down at one point.My DMM didn't have peakhold so I had to record it.Results:65.3V AC * 85.8A AC5602.74 Watts MaxDC Voltage dropped down to about 11.5V during the clamp.My DC Audio system doesn't sound as loud as my old 1200W eD system so I really hope getting a new box built by CJ will help the output. I still have to find a new place to put the XP3000 if I want to do this just to make space inside the trunk. Maybe put the XP3000 behind the passenger seat? Who knows. I wish I had more room to work with. -
I need more batteries for my DC5K then?
I'd get more batteries for my car but the trunk is so limited in space and my rear is already sagging
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Got all of my gains setup.
Apparently I've only been powering each sub with about 950W RMS because my stock alternator can't handle anything more.
50hz @0dB tone was used to set gains on the DC5K. I am way under powering these subs.
Next up, I will install the Singer Alternator and retune my gains for a higher and more proper power.
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When you set the gain on your amp, turn the sub sonic all the way down and the lpf all the way up. Once the gain is set, then you can set your filters.
Alright I'll do it the correct way so that I don't have to go back and retune everything in the future. The last thing I want is to have some weird slope from the filter settings affecting my tuning.
DC5K Clamp Test - Second Try with oscope hooked up
in DC Sound Lab - Big Bass on ANOTHER LEVEL!
Posted · Edited by moh.vze.com
How do I know which AC Voltage reading is correct? There seems to be a ~3Volt difference between the Oscope and the DMM reading.
I'll probably do another run on all of those different frequencies again tomorrow once someone confirms if it's ok to be somewhat clipping when doing this just for the sake of results -.-
I will also use the DMM for DC Current readings. When I ran these tests, I think the lowest voltage I saw was 11.5V. Average was more around 12V though.