Can I obtain the best phase response without performing measurements? If so, how to achieve it?
Also, how did the speaker manufacturers in the 70s and 80s (pre-1985) manipulate the phase response at that moment?
Also, how did the speaker manufacturers in the 70s and 80s (pre-1985) manipulate the phase response at that moment?
No, you can not.
What is so hard about performing measurements? If you have computer, software is free and umic is cheap.
There is no excuse not to measure. Unless you want to keep posting nonsense.
What is so hard about performing measurements? If you have computer, software is free and umic is cheap.
There is no excuse not to measure. Unless you want to keep posting nonsense.
I could do some pretty good guessing if forced to. It would take more work to do well than measuring would.
It IS possible to measure-by-ear, moving one driver while playing a tone or even music. I'm sure the ancients did.
wchang, yes that's probably your best bet. If you can find 180 degrees then you can estimate others. Getting the slope right may take some more guessing. You can't test for a null as easily when the levels are not the same, as they would be away from the cross.
How would you know if you had it without measurement?
Can you draw a straight line that's exactly 100 mm long without a ruler? I don't understand the opposition to measurements either.
Tom
Tom
"Best" ? No chance. (unless it's a full ranger LoL)
Close? Maybe, but only if we are talking about the very simplest of two-ways)
Multi-way speakers in general...forget it.
The better manufacturers? They measured in anechoic chambers, plotting sine wave responses by hand, then applied Fourier analysis again mostly by hand, or maybe used Time Delay Spectrometry if they were advanced / had the resources...
I didn’t oppose the measurements but I was just curious how did the speaker builders do it in those days without computer/software aided?
I used to hear someone suggesting they used Laplace Transform but I’ve never heard the use of Fourier Transform with loudspeaker indeed. This is my confusion. Please help clarify.
FFT is used to derive the impulse response using the inverse of the measured frequency response amongst other things.
Computer based acoustical measurement techniques have been around since the 1960s, before that I suppose they would have used discrete amplitude and phase measurements at a number of frequencies and used math to graph FR /phase (basically a bode plot) and derive impulse response.
I second the recommendation to use UMIK-1 mic and recommend REW as a primary measurement tool. A cheap USB stereo dac is the other bit of kit required although some laptops have decent dacs and headphone outputs.
Computer based acoustical measurement techniques have been around since the 1960s, before that I suppose they would have used discrete amplitude and phase measurements at a number of frequencies and used math to graph FR /phase (basically a bode plot) and derive impulse response.
I second the recommendation to use UMIK-1 mic and recommend REW as a primary measurement tool. A cheap USB stereo dac is the other bit of kit required although some laptops have decent dacs and headphone outputs.
I believe the Laplace transform can be associated with loudspeaker transient response.