Line array corner sub

[Hara]

This thread may very well have been dead for a while, but I feel that rather than starting a new thread, posting here would be more relevent (and to show I did at least do some reading)

It seems the original intent of the poster was to produce a cheap subwoofer by using smaller drivers 8" but in higher quantity. I agree with the argument to go with a single or double 12" instead of several 8". With my project (or more like pipe dream at the moment... until someone responds to my emails...), I feel that perhaps it might work in my case where I plan to use 4, 12" quality drivers instead of a large 18" (or 24" which is required to equal surface area) which is usually very expensive.

A possible enclosure would be similar to
http://www.ultimateavmag.com/feature...ay/index4.html

But I also thought about 2 drivers in front, and 2 drivers in the rear also facing the front while out of phase (push-pull out of phase) to cancel non-linearities in a sealed enclosure.

I looked into TL such as the sonotube for lower cutoff-frequency, but the size of the enclosure, construction complexity, output from the port creating even more complicated room interactions, and reasoning supposedly sealed has the ideal transient response has persuaded me otherwise (unless someone else has something to add in favor of a TL).

I figure that the multiple driver setupwill help get the low frequency of 20hz easily, and 15hz @ >-3db

I am not concerned with max spl, just 15hz-60hz (actually even as low as 40hz) type of output at low distortion levels and moderate listening levels 80-90db

I'm not sure how much wattage I will be needing either (regarding adding more drivers). My configuration for wiring would be 2 parallel drivers in a series, to get back to 8 ohms.

Comments and subwoofer advice please!

[Volenti]

Originally posted by Hara


I looked into TL such as the sonotube for lower cutoff-frequency, but the size of the enclosure, construction complexity, output from the port creating even more complicated room interactions, and reasoning supposedly sealed has the ideal transient response has persuaded me otherwise (unless someone else has something to add in favor of a TL).

In my exprimenting with TL's I found long straight TL's can have issues with either end exciting different room modes. I've cut said lines in two and folded them with a smooth 180 degree curve so the driver and opening are together and eliminated the weird mode issues. (normal room mode behaviour still applies though)

Though folding a sonotube based TL is easier said then done

[Hara]

What about comparing relative size? Which is larger, folded tube with 2 12" drivers? or 4" in a sealed?

[Hara]

Whops typo, I meant 2, 12" drivers in a folded tube, or 4, 12" in a sealed assuming they are the same drivers. The idea is that I'm trying to take advantage of a deal of several quality drivers.

[johninCR]

Originally posted by Volenti
Though folding a sonotube based TL is easier said then done

That's actually quite simple. Just use a larger diameter tube, cut a piece of plywood with a width the same as the tube diameter, insert the plywood and glue and screw and viola.

[Volenti]

Originally posted by Hara
Whops typo, I meant 2, 12" drivers in a folded tube, or 4, 12" in a sealed assuming they are the same drivers. The idea is that I'm trying to take advantage of a deal of several quality drivers.

A folded T-line to suit 2x 12'' drivers could be up to 20cuft, you could fit 4x 12'' sealed in about half that, depending on their vas and your alignment preference.

[Hara]

Thats what I thought, I just couldn't simulate anything... especially since I have no driver parameters at the moment, I can only get those once I get the drivers and find them out by hand. I was hoping to draw from the experience of others.

For sealed designs, I am getting in the works to learning Speaker Workshop. Any other recommended resources specifically for sealed designs?

Also any critique on the strategy? Perhaps I'll have to wait until I get the drivers...