Alpha TL spreadsheet revised........


Attached is v2. Steve Erickson (aka 'dumbass') pointed out a discrepency in Rick's article that I missed. At the time I did the SS for myself I just inputted the formulas without really reading the article or paying any attention to the example, which shows a somewhat different formula for 'a' (alpha) that in most cases yields a considerably smaller pipe area (CSA).

This damps the system better, lowering the Q of the roll off slope, but you lose some gain, so depending on the driver/app it can be a bit too 'lean' IMO. As always though YMMV.

Rick also points out what tuning to use for a max flat impedance alignment so I added it in the 'conversion' window just in case it's high on your performance parameter list, but with typical Qts drivers it will severely limit LF output and requires so much stuffing you can't ~accurately model it in MJK's WS. Not to mention it will probably 'suck the life' out of a 'fullrange' driver's performance (overdamped transients due to excessive acoustic mass loading). Great for lowering the Q of a high Qts driver though.



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I loaded a few numbers in your spreadsheet and well, they matched vent tuning from WinISD (see pic). Your spreadsheet appears to have enough info to build a BLH with exception of the horn mouth. Will you be expanding the calculations to peform BLH results. PS... may need instructions should you expand on this.

I haven't figured out how to use Mathcad BLH spreadsheet yet.

I'm building a folded BLH using HiVi A2S driver, compression chamber is 1 liter, 44" tappered vent for horn at 1/16" per 1", tuned 70hz.

This is a small driver and my first try at any BLH. This experiment is just that an experiment to hear a minature horn. I can't tune lower without increasing enclosure horn size.



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