Strange problem - Phase Cancellation?

[stevem]

Thanks for all the responses everyone, I appreciate the help.

Earl, you've given me quite a lot to think about. I see what you're saying about adding delay to change the phase relationships between the drivers. It makes sense. You put a lot of effort in explaining it so I'll know how to apply the delay, and how to make some sense of the result. Thank you. Now my problem is the time to experiment with it, because I'm about to leave for a week's vacation. It might have to wait until I get back.

I also should have mentioned another feature of the BSS, but until now I didn't know what, if any, the relevance was. In addition to the ability to select "normal' and "invert" for each driver's polarity, you can also adjust the phase of drivers from 0 degrees to 180 degrees in 5 degree increments. With the unit configured as a 3-way (LMH), you can adjust the mid and the woofer's phase, but not the tweeter. In the 2-way configuration (LH) you can adjust the phase of the woofer. I assume that the tweeter is not adjustable, because the tweeter becomes your reference point, and you are always adjusting the midrange and/or woofer to it. Would you suggest using these adjustments instead of varying the delays? I haven't even tried them to see what effect they have.

I also wonder about trying to adjust phase so you don't have cancellation at the crossover. How do the different phase relationships between drivers effect the overall sound of the system? Is it better to have all the divers in phase with each other, and not worry so much about the crossover points? Is absolute phase reversal audible? I sure think I hear a difference. Am I just being a "tweak" to worry about it?

[Earl K]

I also wonder about trying to adjust phase so you don't have cancellation at the crossover.

- Then, when you're back from your holidays try my suggestions. ( Or try using the smaller increments that you mention are built into the unit )

- How do the different phase relationships between drivers effect the overall sound of the system?

- Remember that all this talk / is only about phase relationships that exist within the crossover zones. When two acoustic sections are slightly out of phase / you'll get less summation .
- Most people will say that the typical listener is unaware of phase relationships per se / they do point out that what people can hear are the overall level changes caused by phase relationships. .

Is it better to have all the divers in phase with each other, and not worry so much about the crossover points?

- Please, remember you're talking about phase relationships that occur only in the crossover zones / nowhere else ! All three of your drivers have the same polarities. Your new Cricket demonstrated that.
- Out in the pass-bands of the 3 drivers ( which is the greatest percentage of what you listen to ) there is minimal to no phase change to worry about. Your drivers are all moving in tandem / which happens to be the beauty of using crossovers that utilyze slopes that are multiples of 24 db / octave .

Is absolute phase reversal audible? I sure think I hear a difference. Am I just being a "tweak" to worry about it?

- The term is absolute polarity !
- I wish you guys would stop using these two terms as if they were interchangeable .
- Some people claim to hear reversed polarities making a difference on percussive sounds .
- I do find the entire concept of listening to a system that flips polarities in one area anathema to my concept of listening. I understand the necessity to achieve decent summations in the crossover area / but I still don't like the concept. Of course this is the "Normal" situation with just about anything you might buy & listen to, in Home HiFi. ( The whole idea, still drives me nuts which is why, I prefer to make my own DIY systems )


Anyways, Bon Voyage !

[Tom Loizeaux]

Guys, this is a great thread! It's a little hard to follow...but that's what makes it so interesting. A special thanks to Earl for sharing his amazing insight and knowledge.
I suspect we would all benifit from figuring out how to tweak the electrical alignments of our home systems.
Thanks again.

Tom