Scratching my head thinking about the best way to make a phase plug for a 12" midbass FLH. I need clean linear response from 150 to 800 hz and plan on using a tractrix profile for the low distortion to mate with a 2" coax CD crossed at 500 hz. The midbass driver is a B&C 12MH32.
Any thoughts on a simple method of making a good phase plug mold or using other method of construction?
Any thoughts on a simple method of making a good phase plug mold or using other method of construction?
@AllenB - Your probably right about not needing one for that little BW, but I may try to use this as a modular midbass cab to use with other smaller horn drivers, say up to maybe 1k with a shallow slope.
I was playing around with hornresp and found that with Ah=200cm2 and Am=4000cm2, it creates a larger front chamber volume with common construction methods and without a phase plug it may hurt the desired top end extension. Hornresp doesn't always predict the upper cutoff limit very well, so I'd rather be safe than sorry.
I was playing around with hornresp and found that with Ah=200cm2 and Am=4000cm2, it creates a larger front chamber volume with common construction methods and without a phase plug it may hurt the desired top end extension. Hornresp doesn't always predict the upper cutoff limit very well, so I'd rather be safe than sorry.
Some say that exponentials are better with a throat chamber but the tractrix isn't your average exponential.
There's more to a phase plug than what frequency you want to go to. One phase plug won't fit all horns. What is your compression ratio?
There's more to a phase plug than what frequency you want to go to. One phase plug won't fit all horns. What is your compression ratio?
Last edited:
I wouldn't want more than about 3:1 ratio. The higher ratios usually sound worse in a cone mid horn driver setup. The 12MH32 has a fairly sturdy cone but its a bit on the lighter side. I dont think it will sound good with higher comp ratios. Exponential horn would have the size advantage but I like the sound of a tractrix when run into the low end rollof area. Passive time alignment is also important to me, so I'd rather go with a horn length / size that plays nice with the mid driver + WG length of less than 12 inches. Not sure how a 500 hz xover dictates which alignment to get phase right without delay and at which slope.