well technically speaking your cd, usb, or ipod can introduce a whole new element that causes distortion or varying output as well since songs are burned or pressed at different bitrates so even if u set gains PERFECTLY you can throw in a cd with a really high bitrate and blow anything. ANYTHING CAN HAPPEN. No method is perfect, not even an oscope by itself.
Amplifiers work as a voltage gain, meaning it sets the output voltage and lets the current vary. Your output voltage is the same regardless of the impedance. Your looking at the numbers from the wrong side. I don't know of many amplifiers that can produce the same power at different impedances so your voltage examples are useless. This is how you should be looking at it.
No. You are misinformed Bubba. The voltage changes with frequency. Also the resistance changes with frequency. Current is NOT the only variable.
I understand that there are a majority of amps that the ratings double as the impedance is halved, but lower quality amps such as a Hifonics Brutus will have a similar problem to the JL because their ratings at a lower impedance change from the relationship of wattage and load in your example. In those cases the voltage output from the amp could be too high for the final load, the current could increase to a point beyond what the amplifier is capable of handling. The SMD device does not compensate for those situations, it ignores voltage output and final load completely yet claims to be a tool for setting gains. In reality it only does one thing, it looks for 1%THD. If someone buys this and doesn't understand that, they will follow the instructions and potentially damage their equipment. Without some kind of a warning or change of the instructions this is pretty useless at any price.
Yes, I agree but given the fact that your using a test tone I think we can agree the frequency is a constant here, no?
Of course it doesn't find the actual power coming it. From my understanding it just matches a 40hz sine wave to what it thinks a perfect one looks like, it doesn't go by what your amp is rated at and doing that with the DMM is pretty inaccurate. In theory when an amp cuts the resistance in half the power should double, but that's not the case with amps because of efficiency. That's why you see a 900 watt rating at 2 ohm and 1500 at 1 ohm because it is move efficient at 2 ohm. You can't magically make your amp do rated, so this finds where it's clean, and that's it, it's clean, and if your DMM says you don't have the AC voltage you should, then it's your amp's problem, not the DD-1.
Here is what you are failing to understand, I'm not talking about amps that can't even produce rated power. I'm talking about amps that can produce rated but, because of the parts used and the heat dissipation of the amp can't handle the full current of a 1Ω load. With no load on the amp the "clean" voltage will likely be higher than with a load. So using your example the amp is rated for 900W@2Ω - 42.2VAC and 1500W@1Ω - 38.7VAC. Using the DD-1 to find the "clean" unloaded output the voltage will likely be over 42.2VAC, so you have just set your gains to greater than 42.2VAC. As soon as you reconnect your 1Ω sub and complete that circuit is where you are going to have a problem, because the current is now higher, potentially higher than what the amp can handle. The amp may have no trouble doing a rated 1500W@1Ω, because the parts inside can handle the current and the amp can dissipate the heat, but now you are asking it to do over 1780W@1Ω because that is what the "clean" voltage is set for. The voltage wont suddenly drop to a safe level as soon as you reconnect the sub.
nope DMM is best you can do without an oscope. past that by ear.......
Just looking at the misinformation on this thread is enough to tell me that that's a great marketing strategy. Masses of nit-wits think he is the end-all of 12V electronics and would buy anything he sold with that pitch. They'll post their own youtube videos saying how great it is and more youtube nitwits will buy them.
I agree here.
