It was my wife's idea originally. I was describing how I wanted to position and move the mic during measurements, and she suggested her camera tripod might work...
Member
Joined 2003
I'm a bit puzzle on this phase adjustment or delay on active crossover. I agree it works correctly on axis.
But it adds delay also off axis where it should probably not be added.
We can clearly see on the pic that that at 90 it is already align (I never done the exercise to make a measurment taught)
I fully agree that it is better to time align on axis rather than 90deg
But it's not obvious that making a steped baffle is worse than having off axis to be not time align ...
By the way, having a Umik all those questions of phase and time alignment bother me.
Jeff bagby method works quite well on axis. But when it comes to take off-axis measurement I'm not sure to do it correctly ...
And I even don't know if we NEED to make measurement mooving mic on Y axis to always be at driver hight. Or we just can keep it at same height. (especially for vertical measurement) ?
Member
Joined 2003
Ditch the USB mic, use standard XLR mic with USB audio Interface. Loopback (ie dual channel measurement) captures timing information with every measurement, skip "Jeff Bagby method" (he didn't invent it), follow measurement guide for VituixCAD for correct process.
Member
Joined 2003
The problem I had when looking at camera tripods is that the centre column for vertical height adjustment is limited in length, shorter than what I'd want for measuring a 3-way speaker. So when you need more adjustment beyond that you have to adjust all 3 legs individually, a lot more involved than the single adjustment required on a normal mic stand.
The key when shopping for mic stands is to get a good base support. This type is good and sturdy:
This type is bad and floppy:
Besides this, when measuring individual drivers, in order to maximize the window length measuring indoors, it is actually better to keep the mic situated in it's ideal location 1/2 way between floor and ceiling, and elevate the speaker to be in line with the mic if possible. I understand this is not as easily accomplished and may not be possible in some situations.
The key when shopping for mic stands is to get a good base support. This type is good and sturdy:
This type is bad and floppy:
Besides this, when measuring individual drivers, in order to maximize the window length measuring indoors, it is actually better to keep the mic situated in it's ideal location 1/2 way between floor and ceiling, and elevate the speaker to be in line with the mic if possible. I understand this is not as easily accomplished and may not be possible in some situations.
This is one of the reasons why I initially looked for a height adjustment solution for my measuring turret.
Interestingly, this is something I’ve been thinking about just recently too. The approach I’ve decided to take consists of fixing the baffle to microphone distance. The drive units will be mounted on sub-baffles of equal thickness. Calculating the relative offsets should then be an easy task.
