Thanks for your reply!

I just did a search at the 'high efficiency' forum that hit a message from Bruce Edgar (see below) that may be the one you refer to - at least it corresponds quite well with your memory!

http://www.audioasylum.com/forums/HUG/messages/24987.html

(I hope it's o.k. to refer to other peoples post in this way - if not please let me know)

Here Bruce Edgar claims that only misalignments larger than 1 foot can be heard and primarily at higher frequences.

In a related post Bruce Edgar states that using 1. order crossovers minimizes the errors even further.

Have you any idea whether 4th. order crossovers would makes potential alignment problems worse - and if yes why?

Regards
Peter K.

Thanks for your reply. Yes, there is a lot of good information in your archives (a lot for me to read and learn!)

Regards
Peter K.

This incident was one of the things that spurred Hilliard to get his boss at MGM to finance the development of an improved theater playback speaker, the famous Shearer Horn. Hilliard went on to be the big Kahuna of engineering at Altec and is the Zeus of The Horn Gods.

• Chicago Horn Club

Thanks for bringing up this nice and illustrative piece of history!

Regards
Peter

P.S.: Nice Chicago Horn Club website!

The apparent offset of the driver is proportional to phase shift divided by frequency. Phase shift is proportional to the arctan of the measurement frequency divided by the crossover frequency. When this ratio is small (i.e., when f

It isn't so much that there is an abstract concept of time and that capacitors cause a "time warp." But it is that current leads voltage in a capacitor, and that voltage leads current in an inductor. Current and voltage rise at the same rate in a resistor. That's why the delays are described as they are in a reactive device, and the issues that are represented by phase are actual, measurable and identifiable properties in the time domain.

Now, change the input signal to a 1600Hz toneburst. Whereas the output of the low-pass filter will begin to change just as soon as the leading edge of the toneburst arrives (ignoring propagation delay, i.e., the speed of light), absolutely nothing will come out of the second filter until 156.25uS have passed. So, while both filters have a delay, in some qualifiable way, the nature of the delays is different. I suppose you could say, sT compared to 1 / (1 + sT).

Anyway, I guess I'm getting a bit too esoteric. It's just something I started thinking about after reading your article. Again, sorry if this is inappropriate material for the forum.