el pipe-o

[mantisory]

Hi all,
I am just wondering whether anyone has done an el pipe-o or similar with the adire extremis...I have a couple kicking around that i'd like to use for a sub and am unsure which way to go...
thanks,
byron

[GM]

No, but should work OK. Personally, I prefer to put low Vas drivers in a TQWT (reverse tapered) or better yet, a tapped TQWT now that we can sim them.

GM

[nuconz]

Originally posted by GM
No, but should work OK. Personally, I prefer to put low Vas drivers in a TQWT (reverse tapered) or better yet, a tapped TQWT now that we can sim them.

GM

ok, i'll bite - how is low Vas determined?

[Moondog55]

I'll bite too, for a different reason, what exactly is a tapped QWTL and how does it differ from a tapped horn??
So far none of my in stock drivers seems to be suitable for a tapped horn so I have not paid much attention to that series of threads.

[GM]

Originally posted by nuconz

ok, i'll bite - how is low Vas determined?

If a T/S max flat alignment requires a vent that's large/long enough to have vent harmonics low enough in frequency (i.e. high amplitude/Q peak) to comb filter with the main's BW and meet the 5% mach vent peak speed limit (~56.5 ft/s (17.22 m/s)) at whatever the predicted power required, then Vas is low, which means many (most?) current drivers fall into this category to minimize box size at the expense of acoustic efficiency. Or you can just arbitrarily use the old rule-of-thumb of ~13.78"/35 cm at rated amp power.

GM

[GM]

Originally posted by Moondog55
I'll bite too, for a different reason, what exactly is a tapped QWTL and how does it differ from a tapped horn??

It's a reverse tapered TL (TQWT) except tapped whereas the typical posted TH is a positive tapered tapped TL (horn).

Recently, me and bjorn have suggested tapped TQWTs in some apps and he's since designed/built a couple, so do a search of him to find the various posts.

GM