Any one use Variovents ? (1 Viewer)

[Fred Seger]

I've just finished another sub. This one is a sealed tempest in a 130L box, with a 100 watt plate amp. I'm happy with the results but was wondering how variovents would affect the performance.
Thanks

 

[Greg Monfort]

If the VCs are wired in parallel, then you'll lose a bunch of bass; if only one is driven and the other one is open, then it will flatten the midbass hump.
GM
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Loud is beautiful, if it's clean

 

[Jack Gilvey]

Fred, tell us more about yer sub, we like details...

 

[Fred Seger]

Box ouside dimensions are 21.5x21.5x21.5. Made of 3/4"
MDF. Two internal cross braces. Stuffed with about 2 pounds of acousta-stuff. Has black chrome metal spike legs. The plate amp is PE 300-792 which puts out 110 watts RMS into 8 ohms or 156 watts RMS into 4 ohms. It also has a 5db boost at 35hz.(which I might change to get a bit more extension) The tempest has the VC's hooked up in parallel.
If I could find my digital camera I would take a picture of it, along with my other subs, a dual Shiva EBS, sealed Titanic, and Dayton DVC 15" bandpass.
I did some 1 meter measurements in my 30x30 basement, using the NCH tone generator and a RS SPL meter.
It was flat ( +/- 1.5 db) to 30 hz then it dropped of quickly and was -10 db at 20 hz. It's final home will be in the family room at my sister's house, which is bigger than my basement. It will be used 50/50 for HT and music. Size was a big issue to her, as was price. For under $300 (minus labor ) I'm happy with the results, but am always looking for a way to squeeze more performance out.
I have ZERO experience with variovents and am not really sure exactly how or why they work.
Thanks for your help Greg and Jack and everyone else.