woofer placement near floor in a 3 way

tajanes

Thoughts on floor pickup effect outweighing separation btwn mid and woofer?
While Tw to Mid close spacing is critical, not so much for Mid to Woofer?

Haven't seen where Magico has set the Xover (maybe quite low for a mid) but at 360Hz (or a bit higher for many 3 ways) the ½ wavelength is ~ 1.6ft, which these speakers' center-to-center (Woofer - Mid) may be pushing.

tktran

You can model the effects in a good baffle diffraction simulator; also helps you select crossover frequency to good effect.

hifiside

If you do bigger woofers you can get the best of both worlds. My .02

DrewsBrews

@hifiside said:
If you do bigger woofers you can get the best of both worlds. My .02

I like how this guy thinks!

If frequency allows the c2c spacing to drop them down, then keeping them higher up is probably more cosmetic choice. We are creatures of habit.

Also if woofers have much cone mass (such as heavy subwoofer cones) then having them lower down would help reduce the rocking motion.

a4eaudio

@tajanes said:
Thoughts on floor pickup effect outweighing separation btwn mid and woofer?>

Have you seen this recent thread? Starting at the comment below, the conversation turns to several interesting takes on floor bounce.

https://diy.midwestaudio.club/discussion/comment/36712/#Comment_36712

And PWRRYD's comment on Jan 8 I think addresses your point about separation between mid and woofer.

tajanes

Thx for the link - I’ll take a look

rjj45

thanks - that actually explains a lot. For my "als compact 3 way", I was considering putting the UM12 near the floor for a bit of gain, and sure enough, it would have worked. (But that design has been abandoned)

tajanes

Addressing timing (path lengths) issues in an example and doing some guesstimates: say seating 12 feet from base of speaker with ear height 44 inches, with a speaker coaxial mid/tweeter center height at 33 inches and woofer center height at 9 inches from floor > creates a difference of about 5 inches ear to drivers (coaxial vs. woofer).

Tilting the speaker baffle back by ~ 9 degrees would get the path lengths in line, but best (?) IMO to hold tilt to ~ 4 degrees to keep coaxial mid/tweeter directed in line to ear, which still would narrow the difference to approx 2 inches. Build and measure...