Deciding on a sub

[cyberspyder]

Any good plans? Want a cube, so no Sonosubs or stacks, as it'll be in a corner most likely. Looking to spend up to $300. How's this?

http://www.vikash.info/audio/xls10/

Which is better, a port or a passive radiator?

Brendan

[Bear]

A passive radiator has no port noise, but a flared port is typically cheaper. Also, depending upon the size and tuning of the port you want, you may lose less of the internal volume ("net air") in the enclosure using a PR than using a port (you subtract the port volume from the box volume to get the net enclosure volume).

[cyberspyder]

Which offers a deeper bass response?

[ThomasW]

They're both 'vented' alignments, they can have identical tunings.

[JoeAngelicchio]

How would one calculate for a passive radiator?
Joe

[ThomasW]

Use WinISD Pro or Unibox. The Fb is determined by the weight of the PR.

[Finleyville]

The Fb is determined by the weight of the PR.

You mean the weight of the moving mass and not the weight of the whole radiator, right?

[Mazeroth]

You mean the weight of the moving mass and not the weight of the whole radiator, right?

Correct.

[brent_s]

$300 Canadian or US? It makes a difference. What does that budget include...driver, PR/port, amp, cabinet material? Any size limitations? Output and extension goals?

Down firing a PR as Vikash did is usually a very bad idea. That puts a lot of stress on the suspension and will compromise the life expectancy of the PR.

For $350ish USD, you could build something resembling the Salk Songsub. Pair the Dayton RS315-HO with an AE PR15-1050 in 2 ft^3 net for a 21Hz tuning. Using the Dayton BASH-300, you're looking at an f3 of 21Hz with 105dB@20hz - 109dB@100hz according to the 1m groundplane sims in WinISD.

If you can go larger on the cabinet, I'm using a Dayton DVC15 in 6 ft^3 net tuned to 17Hz via one full length 4" PSP. With the DVC15 corner loaded in my 24x16x9 theater room, it measured essentialy flat (+/-3) down to 10Hz. Obviously, I don't have a rumble filter in the chain; the rumble filter in the BASH-300 will start rolling you off at 12dB/octave below 18ish Hz. A DVC15 and BASH-300 would fit your $300 budget.

Lots of ways to skin that cat.

-Brent