Woofer waveguides?

[dirkwright]

I'm building a little 2 way with an 8" B&C woofer and one of their horn tweeters. The tweeter is considerably deeper than the woofer, so I want to offset mount them front to back such that their approximate acoustical centers line up vertically (aka "time align" the drivers). I cannot find much information on recessing the woofer into a short waveguide. I found this company doing it:
DESIGN - CONSTRUCTION
They claim it smooths the crossover transition.

Anyone have any opinions or information on this idea?

[johnB23]

Im assuming this is a sealed or ported box for the woofer, so any wave guide wouldnt really have an effect on the performance of the cabinet. The only way a waveguide would actually be effective for a woofer is if you used it in a tappedhorn configuration...but you said little some im guessing not ;D.

If you want to recess the woofer, just do so, it wont really matter much.

[DSP_Geek]

Remember the woofer will have an acoustic delay because it's a lowpass system, partly mechanical and partly because Le in series with Re creates a first-order lowpass filter with its own phase lag. Merely aligning the voice coils isn't enough; most often the tweeter voice coil should be a few cm (an inch or two) behind the woofer voice coil.

[dirkwright]

Originally Posted by DSP_Geek

Remember the woofer will have an acoustic delay because it's a lowpass system, partly mechanical and partly because Le in series with Re creates a first-order lowpass filter with its own phase lag. Merely aligning the voice coils isn't enough; most often the tweeter voice coil should be a few cm (an inch or two) behind the woofer voice coil.

Wow, I did not know that. thank you! So, I was estimating a difference of 2.5", but now it seems that it's a wash. I can mount both on the same board.