Originally Posted by
Ian Mackenzie
I agree it is odd.
I did a simulation in bass box .
After you subtract the bracing , drivers and horn then allow for fibreglass the net value is around 130 L.
Just start off bigger and reduce if you feel you need to.[/QUOTE
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Thanks for your comments. So I guess you are advocating that I assume the s-4700 and the M2 are both "about" 130 liter. In one case (s-4700) the vent is tuned to 32Hz and the other ( M2) tuned to mid 20's.
This may partially explain why the s-4700 has about 2 dB more sensitivity, but I am only guessing. I need to check against a winISD simulation to see how much the sensitivity could change went the vent is tuned lower.
I re-read the massive M2 threads and it looks like no one has taken a volt meter and power resistor and actually measured the vent tuning.
Thanks,
-Tom