Driver Baffle Spacing

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Hello All,

Question about the spacing of drivers on a baffle. What are the rules, if any, for placing drivers on a front baffle? I remember reading tweeters and woofer should be seperated by at least 1" or 25.xmm. I have also read that they should be seperated by less than 1 wavelength. What this means, I'm not sure. The author wasn't clear in th DIY article. Does it mean 1 HZ? I don't think so. Does it mean <1 wavelength of the crossover freq? Maybe? Could someone clear this up for me? How is this calculated?

In terms of spacing, is the requirement for spacing center to center or the edge to edge of the drivers?

I have seen some designs where the drives sort of overlap or truncate. Is this a design choice based on the <1 wavelenth requirement or an attempt at point source alignment?

Thanks for any advice you can give.

Vince
 
Hi

here's what I know, and if I am wrong, please correct me.


The distance you have between the tweeter and the midrange will create lobing; hence the further away the tweeter is from the center of the mid range, the higher the cancellation. So, ideally the coaxial prevents this problem. So, no matter where you place the tweeter, the phase will chnage.

Also, the tweeter "should" be time aligned, that is aligned with the voice coil of the mid range.

Trying to eleviate lobing, many use aggressif xovers to cutoff off the frequency response very quickly and make the other driver begin precisely where the cutoff was done. Coherently though, this is to me a nightmare. You hear each and every driver sing its space of frequncy response.


So, hope this helps.
 
The voice coil isn't necessarily the acoustic center of the radiator- it's more likely just a little bit above the dustcap for most cone constructions.

"The higher the cancellation" doesn't really make much sense. The further the acoustic centers of the sources (drivers) are from each other, the lower the frequency that lobing problems begin (and they continue until the lower frequency driver cuts off sufficiently).
 
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