Perusing Parts Express
So I'm looking over P.E.'s Buyout/Clearance section, just seeing what's available and what could actually be considered worthwhile. (Natch, who doesn't like to get the most bang for their buck?) In their Midrange / Midbass / Full Range drivers section, I sorted by price, low to high, and Show All. Skipping over the really tiny TV buyouts, I get to the somewhat larger units, ~4" or so. I check out a few for their specs, mostly they are Meh.
Then I get to this: 4" Treated Paper Cone Woofer 16 Ohm, PN 299-320
I have my good old QuickBasic programs running and it seems to be a decent enough unit for Bass-Reflex. Acoustic Suspension, Nah. But, starting at $5.80 it would be okay for seriously low budget build or "give-aways".
Okay, file that one away for consideration.
On that same (4 across line) is the RESTOCKED Wavecor WF146WA01 5-3/4" Paper Cone Mid-Woofer 4 Ohm, PN 88-298-1164 ( you can see the driver parameters on PN 298-1164). A much more solid unit, but at almost 10x's the price ($50) and new ($69). I ran the same programs for this driver and it is good for both Bass-Reflex and Acoustic Suspension, although I'd go with different designs than supplied on the product page.
Thing is, it's hard to resist the temptation of trying the cheap units, simply because they are so cheap. Here's a screen cap of what I ran:
The top row is the $5.80 no-name with Acoustic Suspension followed by Bass-Reflex while the bottom row is the WaveCor, same order as above. I kept all possible differences the same (box Q for A.S. and port size for B.R.) Now this is just using FO, VAS, and QTS. I could do a Bandpass box or Transmission Line too, but I think those would be better suited to different drivers.
So who else goes through the "catalogs" and does similar research?
I'm guilty and spend way to much time on their website, lol. Some of the buyouts are great, others...not so much. Have to look closely at all of the parameters as theirs usually something about the drivers that makes them less then desirable and therefore so cheap. For instance, the 299-320 has a nice looking response according to the measurements posted on their page. But with only 1mm of Xmax, it's gonna run out of steam fast. With such a limited Xmax, probably best to use it in a sealed enclosure and use another driver to handle the lower octaves.
If you're looking for a great budget 4" to play around with, the TCP115's are hard to beat for the price. $12 each and available in both 4ohm and 8ohm versions.
I saw that it only had 1mm XMax, but it was fun to model it anyway. But something like that in a Line Array would where the load is so spread out that the cones barely move, it would be suitable. Plus, I like the fact that the surround is treated cloth, not foam.
(Just so you guys know, I'm a fan of the old style AlNiCo pincushion speakers. Might explain my weird choices. Maybe. lol!)
I'm on parts express almost daily. I purchased 4 of the 299-320. I'm not trying to get bass out of them simply because of the 1mm xmax. I have them high passed @ 100 hz. I purchased a classic Dayton 8" to handle the lows that only cost me 20$ (open box). One of the reasons I'm on there almost daily for the kind of deals you have to jump on.
I'm powering them with the Dayton 2.1 mini amplifier so not giving them much power. They sound great for what they are. They're no wavecors lol but they are great for a budget project imo.
I have some wavecor drivers too and they are very nice and easy to work with.
I've been eyeballing the hsu sub amplifiers. Their subwoofers don't look too bad either. I modeled the 80$ 12. Didn't look bad at all. Iirr 4 or 4.5 ported would get a fairly flat response tuned to the low 20s.
I've used the 299-609 6.5" woofers. they sound great in a small sealed box too.
Of course, this would be a cool retro build with some of these closeouts.