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TonyD'Amore

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Everything posted by TonyD'Amore

  1. You aren't too far off, but in your example of 40Hz, everything that is in the signal that ISN'T 40Hz isn't harmonic distortion, it is just noise. So removing the 40Hz signal and measuring what is left over isn't measuring harmonic distortion, it is measuring noise. Harmonic distortions happen at precise frequencies, so in the case of the DD-1 it has to measure the fundamental frequenices, and the harmonic frequencies (at the same damn time), then compare the ratio of the amplitude of these things.
  2. The difference between when the DD-1 reads distortion and when it is visible by a human eye on a scope is fairly negligible, IF it is distortion caused by clipping. In terms of dB it would be within a couple of tenths, not 6.5dB, not even 1dB. If the distortion is caused by something other than clipping, there will be a huge difference between the DD-1 and a scope because scopes don't display distortion in a manner that a human eye would be able to read. If I had to make a guess about what happened here, assuming that everything was done correctly and everyone is being honest, I'd guess that the amplifier in question is dirty to the point that it is over 1% THD wayyyy before clipping. This is what the DD-1 saw, thus it said "hey I see excessive distortion". It is up to the operator of the device to determine the source of said distortion. When used to set gain, if you start with the gain down and the correct overlap track and the DD-1 reads the signal as clean, and then one proceeds to turn up the gain until the distortion LED illuminates you are pretty guaranteed that the distortion it is reading is due to clipping and you have now set the gain properly. HOWEVER, there are some seriously dirty noisy ass class D amplifiers on the market these days, and the DD-1 will call them out every time. The DD-1 is pretty amazing, but it's not magic or psychic. If this were happening in my install, I would check the signal from the front to the rear making sure everything stays distortion free throughout the entire range of the volume control (up until the point where we know the source distorts). If that the signal is clean all the way through the volume range, but distorted at the amplifier intermittently or continuously throughout the volume range, then we know exactly where the problem lies. Without seeing any of what happened first hand, this is my best guess.
  3. The rubber boot at the end can be removed, it is only cosmetic really. The strain relief for the cable is inside the barrel. This might help, or we can offer 90 degree adapters.
  4. The AD-1 was designed to NOT NEED a bench or any lab equipment. It contains everything you need already. Put it on a cart, wheel it over to the vehicle that needs to be dyno'd, connect it to the amp. Done. Real in car dynos is what it is about. This provides the dealers a route to sell upgraded alternators, batteries, and wiring....as well as real amplifiers.
  5. 10 X LOG (.46/10) = 11% power difference. 11% power difference = 11% impedance difference. So from 1.00 ohm to 1.11 ohms. Totally possible with very little heat.
  6. These are shipping now!! Black Friday Sale time!! http://www.stevemeadedesigns.com/board/topic/155948-damore-engineering-subwoofers-released-black-fri-sale/page__hl__%2Bd%26%2339%3Bamore+%2Bengineering
  7. The D'Amore Engineering AF subwoofer line is shipping now! Just in time for the holiday. We are running Black Friday Week starting tonight at 8pm. These are single 4 ohm coil, LOW Bass in a small enclosure, very low distortion, VERY musical subwoofers. The coils are around 3.5 ohms making them great for a single woofer on a single Class A/B amp bridged, or a 3 or 4 subwoofer system on a 1 ohm stable mono amplifier. EVERY single one of these is fully tested before they leave here and come with the ACTUAL T/S parameters for that specific woofer!!! An industry first? Take a look at them here: http://www.damoreengineering.com/subwoofers.html For the sale, here is what we are doing: Buy 1, get 1 at 50% off Buy 2, get 1 free!
  8. That looks fantastic actually! The numbers should be the same whether parallel or series. With the exception of the impedance numbers obviously. Nice work! Very consistent
  9. All components are now at D'Amore Engineering HQ. They will be in pre - production while we are at SEMA (owner's manuals, boxes, harnesses, ect), and full assembly promptly when we return from SEMA. We will be shipping by the 8th I'm sure. We might setup a webcam on the production of these starting on the 5th
  10. One minor problem here. Lets assume a 300 Amp alt at 14V = 4200 watts output. Assume 80% efficiency to convert the energy: so input to the electric motor = 5250 watts. So at 110V that would be 48 amps (not gonna happen). You would need a 30 Amp 220V setup with a 7 horsepower motor. Cool idea though
  11. Here is the link, feel free to leave feeback. I'm sure there may be a typo or two, please let us know. Follow the link to the IM-SG page. direct download of entire manual here: http://damoreengineering.com/im-sg.html
  12. I don't know CJ, we are talking 0.46dB. If the voice coil temperature changed between runs you might see this. Can you get those results consistantly?
  13. The RCA output voltage will not drop with B+ voltage dropping. The RCA outputs are fed from a mini-amplifier inside the headunit that has feedback. Think of it as regulated
  14. I noticed this personaly on my own ride. I have Chrysler 300 with the stock HU that has a Rockford BLD (3Sixty Line Driver) for the added sub stage . My sub stage is a fully upgraded single 10" DC XL m2 running off a DC 2.0k. The line driver has 2 modes Balanced and Unbalanaced. In Balanced mode it produces 22 Vrms and 11 Vrms in Unbalanced mode. When setting my gains (line driver hace a gain as well) with the DD-1 , I noticed that in balanced mode I get full time distortion on 0db 40hz track. But in balanced mode I can addjust the gains slightly (if at all). Also when I set the amp if I use the -5bdb track on Unbalanced mode I'll get full time distortion decteted on my DD-1. The reason the BLD is 11 Vrms unbalanced and 22 Vrms balanced is because in unbalanced mode it puts up to 11 Vrms on the center pin of the RCA and grounds the shield. In "balanced" mode it puts 11 Vrms on the center pin of the RCA AND 11 Vrms on the shield!! If your amplifier doesn't have balanced or differential inputs, you are shorting the BLD out in balanced mode. Take a digial meter, set it to ohms, with the amplifier not turned on and the RCAs disconnected measure the resistance from battery ground connection to RCA shield. Let me know
  15. RCA voltage will have no affect on efficency. Every amplifier reguardless of class has some internal gain. Lets say than an amplifier puts out 50 Vac RMS before clipping. Lets also say that the internal gain on this amplifier is 10. That means that it will take 5Vac of input to drive the amplifier to clippling. ( 5Vac X gain of 10 = 50Vac ) The "gain" control on the amplifier is to "gain up" whatever signal is coming in, up to the 5Vac that is required to drive the amplifier to clipping. Example A: There is only 1Vac input to the amp. We adjust the external gain control to have a gain of 5 to drive the amp to clipping. So the 1Vac coming in goes through the "preamp section" of the amplifier where the gain control gains it up to 5Vac. The signal then goes to the "amplifier" section of the amplifier where it internal gain is 10 so now our amplifier puts out 50Vac. The gain pot on this amp is probably 1/2 way up or so Example B: There is 5Vac input to the amp. We adjust the external gain control to have a gain of 1 to drive the amp to clipping. So the 5Vac coming in goes through the "preamp section" of the amplifier where the gain control does nothing so the signal is still 5Vac. The signal then goes to the "amplifier" section of the amplifier where it internal gain is 10 so now our amplifier puts out 50Vac. The gain pot on this amp is all the way down. Same result, no affect on efficency or power output. The only possible difference between example A and example B would be that B could potentially have a slightly "cleaner" signal since the signal would have less chance of picking up alternator whine or other noises as the signal travels from source unit to amplifier.
  16. We are talking about input voltage on the RCAs correct? Battery voltage is not part of this question?
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