"Boom-box" alignment in WinISD?

[philthien]

Anyone ever build something with the "boom-box" alignment from WinISD? I guess they actually call it the "(super) boom-box."

I've been thinking on the W5-1611SAF driver and WinISD likes a .56 cubic foot enclosure and it will hit an F3 of 50-Hz. That is a little larger enclosure than I'd like for my application, though.

So WinISD has a "boom-box" alignment which reduces the box to .355 cubic feet and provides an F3 of 60-Hz and a 1db hump centered at about 100-Hz.

How boomy would that sound? A 1-db hump doesn't seem like much.

Any thoughts on reducing enclosure volume while still getting acceptable in-room bass? I'm going to use these full-range (no sub) for occasional listening. I'm not expecting a ton of bass, just want to come up with the best compromise I can.

[thekorvers]

Re: "Boom-box" alignment in WinISD?

Don't use an enclosure size because WinISD likes it. Use an enclosure size because YOU like it. There is no one perfect size or perfect alignment for a driver!

A driver will work in a variety of sizes. There are always trade-offs in any design and you pick the alignment that works best for you. Determine what are the most important factors for you and design according to that. It could be size, bass extension, flatness, efficiency, SPL, etc., etc.

A 1 dB hump is insignificant IMO and often a designer will introduce a hump in the 50-100 HZ region to increase apparent base when the low frequency extension is limited. Usually when no sub is used.

[Whitneyville1]

Re: "Boom-box" alignment in WinISD?

The T-B driver is very well behaved, not giving the "mountain" bass response curve. You're losing SPL/W in a smaller enclosure, and some F3, BUT, play with the super boom-box alignment to the maximum size enclosure you can live with and see what happens. WinISD is really quite sophisticated, especially the "Pro" version (not just the Alpha). If you can live with .375 cu. ft., you may really be surprised at the results.

[fpitas]

Re: "Boom-box" alignment in WinISD?

If the 1dB peak ends up annoying you, a little Acousta-Stuf will bring it down, albeit at the cost of some port output.

[philthien]

Re: "Boom-box" alignment in WinISD?

If the 1dB peak ends up annoying you, a little Acousta-Stuf will bring it down, albeit at the cost of some port output.

I guess I doubt it would bother me.

I'm just a bit concerned because it is called the "boom-box" alignment, I guess.

[fbov]

Re: "Boom-box" alignment in WinISD?

That concern is warranted at the outset, and is confirmed or assuaged once you see the response curve.

All ported woofer design is a matter of degree... you can dial in how much boom you want with box size and tuning frequency.

But being bass, how much is too much depends on how you'll use it. The corner of a small room is very different from the common boom-box application playing outdoors. In one outdoor application, we went for adjustable "boom"... A fixed 1" long port for +4dB with an F3 of 60Hz, with extensions that take it to flat with F3 of 50Hz.

Conversely, in a small room, I'd tune as low as I can to avoid the boominess inherent in room gain, as I'm an extension hound. You may find a little boom desirable. Look at port length effects in the simulation...

HAve fun,
Frank