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TonyD'Amore

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Everything posted by TonyD'Amore

  1. The 1st installment of the Free Education series of videos is now up for your viewing pleasure. http://damoreengineering.com/freeeducation.html
  2. Do tell Im doing over a 56 and all the runs from my front batt to back batts are cca..... Maybe you should change it and run a 57?
  3. -Resistance is NOT Impedance. -Volts * Amps does NOT equal Watts in AC land -You can NOT use an AC voltmeter and AC current meter to get true power unless you are powering a resistor and are using a scope or clipping detection device. I don't care what your friend the "electrician" said. -You can NOT use a DMM to measure impedance -Clipping is NOT DC -There is NO SUCH THING as Watts RMS (though we use it in audio) -WTH is "Box Rise" -The word "subsonic" to describe low frequency audio is TOTALLY incorrect -CCA wire is NOT OK -Class D is not better, it's cheaper WTH is Class D? D'Amore Engineering will be launching a FREE education section on it's website in the next few days. There will be a series of videos and demonstrations to prove all of the above statements and more. This sport is more full of bad information than the gossip mags at the checkout stand. Something needs to be done. This bad information continues to get passed on, and our hobby continues to be degraded. I'm still paying on my student loans, but it doesn't mean you have to. Stop by www.DAmoreEngineering.com soon, watch some vids, buy a t-shirt.
  4. AD-1 Amplifier Dyno owner's manual has been uploaded to our website for your viewing pleas-zure http://www.damoreengineering.com/ad-1.html
  5. Reason 1) The AD-1 amplifier dyno uses resistive loads. This ensures that the power factor = 1.00 in the equation for AC power, which states Volts * Amps * Power Factor. The equation for DC power is volts * amps. People are using clamps and doing the math for DC power which is totally incorrect. Unless the power factor = 1.00 Which it will not be using subwoofers for "loads". Reason 2) The AD-1 uses our patented DD-1 distortion detection circuitry to make sure that all power that is measured is clean power. (Certified mode) If one doesn't care about distortion or has a Class D amp that always has some distortion the AD-1 can be used in Uncertifed Mode which ignores distortion completely and looks only for clipping. A scope can be used to look for clipping but not distortion. Reason 3) A DMM won't tell you about clipping, as the signal clips, a DMM will keep reading higher and higher, the more you clip the higher it will read. All the way up to 141% higher as the signal completely clips into a square wave. The current clamp will do the same. 141% times 141% = 200%. Double. Just based on that alone clamp "wattage" readings can potentially be wrong by 2x. Amp Dyno does not have this problem. The high speed analog to digital converters and high speed computer inside the AD-1 know what a actual sine wave looks like and will not count any voltage or current that is clipped.
  6. I wanted to say last night that everyone was guessing low, but I have insider info since my monkeywrench avatar is inside that amp so I had to keep quiet. This vintage of Rockford Power Series were heavily underrated.
  7. The AD-1 Amp Dyno has a special mode for amplifiers that have more than 1% distortion on the output, it is the Uncertified Dyno Mode. In this mode, it ignores distortions and only looks for clipping of the signal.
  8. In all fairness to this amplifier, I've never tested one so can't say for sure. Although, basic math would suggest it isn't possible. From their published data: 20kw @ 14.4V with 86% eff. = 20,000 / .86 = 23,255 watts input / 14.4V = 1615 Amps DC. / Three 0 AWG = 538A per 0 AWG. Maybe possible, sounds a little sketchy. But the devil is in the details. That efficency rating is at 4 ohms. At 1 ohm it will be around 65%. They don't mention that. Now doing the same math with real numbers we see that we would need 2136A at 14.4V. This isn't happening on 3 runs of 1/0.
  9. Not picking on any particular brands, though I may call attention to some to show an example. Lying about your product bugs me, but when they claim to be over 15kW things get a bit personal for me. (if you know me you know why) I stumbled on a great example this morning http://www.wooferwarehouse.com/Stetsom-14K2E-Amplifier--1-Ohm-12V_p_120.html They claim 16,200 Watts at 13.8V. I can't wait for someone to dyno one of these, I'm so tried of hearing numbers like 15k, 20k, 25k thrown around like it's no big deal. I am totally confident that there is only 1 mobile audio amplifier that can play music that makes 15k+ on 13.8V. Unfortunatly in the mobile audio world today, "innocent until proven guilty" doesn't apply. The game has changed, the tape measure is here. You are guilty until provent innocent. Dyno it. Prove it.
  10. Curious how you think these companies that grossly over rate their amps are doing their ratings. You reckon they're just making it up? Squaring maximum voltage? Simply making it up
  11. AD-1 can definitely be used to find the difference in these cables. In some testing i've performed at one of my former jobs, I tested various cables (ofc, cca, and different blends of cca) and have seen HUGE differences.
  12. The only exception I've ever seen is the T15kW because the power supply's ridiculous capabilities. The power supply can deliver over 200,000 watts for 1 second, or 2 million watts for 100 milliseconds. It would do 16,000+ clean and 26,000+ fully clipped
  13. Side note: The maximum theoretical power that an amplifier could produce at full clipping (square wave) is double the clean RMS. In the real world it is usually about 30-50% more. So an amp that does 50 watts per channel clean could put out 65-75 watts clipped and distorted to hell. However, the peak SPL wouldn't increase by this same amount, if at all.
  14. You could use clamps to calculate impedance as long as you could guarantee no clipping. Two reasons for this: 1. The number on a digital multimeter will keep increasing after clipping because it is trying to measure the average or RMS value of the sine wave. 2. Clipping produces other frequencies other than the harmonic. 50Hz clipped will generate 100Hz, 150Hz, 200Hz, 250Hz and so on. So if clipping you would be calculating some sort of average of impedances at all of those frequencies combined. As you probably know the IM-SG works well to measure your impedance at any audio frequency you desire. I measured 4.0 ohms at 40Hz on my two 12s ported box in my Jeep. Then when using clamps and burping and recording max numbers it calculated to 3.8 ohms. The difference is I was clipping when clamping. Using clamps and doing the same test but making sure no clipping resulted in 4.0 ohms, just like the IM-SG read. Gotcha that makes sense. Would it hurt the dd-1 to be reading while I am clamping so I know exactly where to stop to ensure an accurate reading for impedance? I have always used the dd-1 with no load on the amp, dont want to use it with a load and damage it. Nope, DD-1 doesn't care. You would have to use 40Hz though.
  15. I believe we are going to do another run of these real soon. We didn't predict the demand of that piece would be so good.
  16. WM-1 isn't out yet. Yes same thing but the WM-1, 2, 3 and such were going to be non-adjustable and calibrated in watts.
  17. You could use clamps to calculate impedance as long as you could guarantee no clipping. Two reasons for this: 1. The number on a digital multimeter will keep increasing after clipping because it is trying to measure the average or RMS value of the sine wave. 2. Clipping produces other frequencies other than the harmonic. 50Hz clipped will generate 100Hz, 150Hz, 200Hz, 250Hz and so on. So if clipping you would be calculating some sort of average of impedances at all of those frequencies combined. As you probably know the IM-SG works well to measure your impedance at any audio frequency you desire. I measured 4.0 ohms at 40Hz on my two 12s ported box in my Jeep. Then when using clamps and burping and recording max numbers it calculated to 3.8 ohms. The difference is I was clipping when clamping. Using clamps and doing the same test but making sure no clipping resulted in 4.0 ohms, just like the IM-SG read.
  18. TM-1 and TM-2 come with a small electronic sensor on a 18 foot long tether. The small sensor is made to be glued to any surface you would like to monitor the temperature of, or just left in mid-air to measure air temp. All you need is some cyanoacrylate glue and your are good to go.
  19. It is similar to another product we have, the VU-DIN. It gets connected to your amplifier output (speaker terminal). Once properly calibrated, it works like an indicator of how close to maximum output your amplifier is. Like a tachometer for your engine, this lets you know when your amplifier is "hitting the redline". You can use multiple units, put one on each speaker output and monitor your entire system.
  20. Not a reactive load, purely resistive. Which is the most difficult load in terms of delivering power. Reactive loads whether inductive or capacitive can be difficult for an amplifier to drive in terms of stability. These are tests that every manufacture should do during the design phase of an amplifier. Once the amplifier's design is set, these things are seldom an issue, and if they were an issue there is nothing a consumer would be able to do about it. Purely resistive loads, or 0 phase loads, tax the power delivery of the amplifier the most. Easy test to do at home, measure amplifier input current while burping some subs at a frequency that is produces a 4 ohm reactive load. Do the same thing on the amp dyno at 4 ohms, or another purely resistive load. You will see the input current to the amplifier at its maximum during the resistive load test.
  21. In fairness to the dyno, it updates the "minimum voltage" it saw WHILE the new maximum power number was found. In other words if the amp being dyno'd hits clipping the power number will stop increasing and thus the battery voltage number will lock in at that power number. Even if the voltage continues to drop. If the amp isn't making any more power, the dyno quits updating the power and voltage numbers. But with all that being said, yes the VM-1 is insanely fast!
  22. Real nice! Time to throw a rechargeable upgrade kit in it! http://damoreengineering.com/foryourtoolbox.html
  23. Hey guys, we have posted a spreadsheet that is downloadable from our website that will perform the complicated math of calculating the T/S parameters for any subwoofer or midbass / midrange you want to measure. Save it, run it, and enable macros. Hit the start button and it will prompt you. You can follow along in the IM-SG owner's manual as you go. Good luck and have fun measuring and designing your enclosure. http://damoreengineering.com/im-sg.html
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