[Don Pearce[_3_]]

On Sun, 5 Jan 2020 13:24:36 -0600, Les Cargill
wrote:

Don Pearce wrote:
On Sat, 4 Jan 2020 18:21:29 -0800 (PST), nickbatz
wrote:

Happy New Year.

So I just dumpster-dived a pair of mid-'80s (guessing) RS Sierra tower speakers from a neighbor.

This is a premature question because I haven't hooked them up yet, but they have 12" rear-firing passive radiators with totally shot foam surrounds.

Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

My guess is that these are hyped speakers, because I know Rogersound Labs and other stereo stores used to compare speakers to JBL L100s in those days. But the tweeter, midrange, and woofer are outwardly in good shape. The cabinets are in reasonable shape, but because I've been doing a lot of woodworking* recently I can easily replace some of the walnut veneer if it's necessary.

TIA

* By the way, if anyone knows anyone in the market for custom studio furniture, especially a unique composer's desk, let me know and and I'll send you some pictures. This has become a serious side business - I just shipped a desk to Paris, another to Florida - and I'm truly enjoying it.

If you have the TS parameters for the main driver, you can probably
design a port that will allow you to do away with the stupid passive
radiator. They are no more than a spring and a mass, just the same as
air in a port tube, but suffer added non-linearity due to the
suspension. Any subwoofer design software will let you do this.

d


Would WinISD be a good choice for this, Don? That's where I'd go first.

WinISD is fine. You can put in the dimensions of your box, and let it
design the port.

d