so when you are testing your tweets by ear do you only listen to the tweets? Same for the mids and subs?
Wait, aren't amplitude and SPL the same? Loudness is a subjective measurement, but amplitude and SPL are scientific, and are a measure of the same thing (wave pressure).npdang said:...our ears are less sensitive to bass frequencies, so when recording a low frequency and a higher frequency tone of the same spl, the low frequency tone is going to have much higher amplitude.
Npdang said:What the "gain knob" does is matches the amplifier's input sensitivity to the maximum output of your source.
noob here.. how to listen each pair of speakers separately?? do i have to remove all the connections from the amp?npdang said:Step by step?
1. Find a heavily compressed cd. Pop music with heavy basslines and blaring instruments is good.
2. Set headunit to max unclipped volume.
3. Make sure no eq is set and that your crossovers are set to protect the drivers from damage. Also all level controls should be set to max.
4. Listen to each pair of speakers (tweeters, mids, sub) separately. Turn the gain up until it's either too loud to stand, or you hear signs of distortion, then back off a bit until it sounds ok.
5. Now go back to your headunit/processor/amp and level match all the speakers by reducing the output of drivers that are too loud.
amprage (sp?) is the measure of electrical current.Casedot said:amplitude is a measure of electrical current, and sound pressure level is a measure of acustical energy. completely different.
A typical clipping indicator can do the trick. But the easiest way would probably be to use a relatively wideband notch filter and a single test frequency. Then measurement of power content would be an approximation to harmonic distortion levels. In other words, a makeshift distortion analyzer to detect the onset of clipping.thechris said:amprage (sp?) is the measure of electrical current.
amplitude is the peak of a wave.
SPL is a measure of acoustic intensity.
setting gains by ear seems like a good idea.
there are issues with the DMM method. i'm working on improving the DMM method by allowing for clipping detection without the need for an OScope.
You don't want to set a ceiling. If you do, then you don't have the extra swing for low-volume tracks. Unless you use the lowest volume track you'll ever use to determine the ceiling, but how would anyone be able to know that?SQ_Bronco said:The only real use a clipping indicator has it to either verify after the fact that your gains are set properly so as not to clip, or to set a ceiling before the fact to prevent clipping. Once you establish the ceiling, you still have to set your actual gain levels by ear during the tuning process.
oddly enough, that's what i've been working on. it seems even a simple twin-t can give sufficient contrast to determine the point of clipping. alternatively you can use unfiltered square waves and the digital volume controls on the HU and just take sucessive measurements. if the amp clips, the ratio between volume settings will change, and quickly end up being 1.MarkZ said:A typical clipping indicator can do the trick. But the easiest way would probably be to use a relatively wideband notch filter and a single test frequency. Then measurement of power content would be an approximation to harmonic distortion levels. In other words, a makeshift distortion analyzer to detect the onset of clipping.
I just can't see where a DMM, OScope, or any other form of equipment would have any application in setting gains. The gain control is basically there for tuning purposes, to set the relative levels of all your channels if you don't have an outboard processor doing the work. There's really no other reason for adjusting it. You set it initially to be roughly where you want the volume knob to be when you clip a "typical" signal. And that's about it.