I have seen quite a few of the old Advents (several models) with the orange tweeters with mesh metal grill over them on Ebay. They seem to go for around $250 a pair; sometimes more. They seem to be very popular.
The Nova's are in Walnut veneer cabinets. Radio Shack specs the woofer out at 12" but I believe it's more like 10". They have an old cone type tweeter top and centered and in between the woofer and the tweeter are a couple of "midranges" which don't look any different than the tweeter. The tweeter and the midranges are set up in a triangular pattern. I guess that they are just set at a different crossover point than the tweeter.
The woofer is actually recessed into the front baffle. It's almost as if they time aligned the speakers, but I don't know if they were that technical about that sort of thing back then.
On the back of the cabinet they provide an RCA type speaker connection and two old screw type connections much like the early 70's type reciever. They are slotted for a flat head screw driver. Also on the back are a couple of switches to adjust the mids and highs. The mids cover 1-7 Khz and the tweeter adjustment is for 7K up. The settings are High, Normal, and Low.
The person who owned these bought them for $77 each. The cabinets are easily worth $40-50. The front grill is similar to pegboard without the wholes or smooth finish and are finished with cloth and a wooden tapestry over that. They are a lot like some of the old Pioneers and Sansui speaker cabinets.
By the way, the link you requested is
http://www.walmart.com/catalog/product.gsp?product_id=3172825&cat=5036&type=4&dept=4104&path=0:4104:4110:5036:164637
They have a sweep of 200 to 2 Hz. They are MP3 @ 64bit recordings that you can streem. They also have some techno and rap that will definetly go down to 20 Hz and probably lower.
Some bonus links are:
http://www.linkwitzlab.com/burst-cd.htm - has a tone burst CD for $20 that includes shipping. Does 20 - 20.
http://www.amusicdirect.com/products/detail.asp?sku=CSTP002 - here's a test cd for $10.
http://www.amusicdirect.com/products/detail.asp?sku=CSTP004
http://www.stryke.com/basszone/testcd.html - this one is ~$12 and goes down to 10Hz
By the way, these are sealed, acoustic suspension. I use to think that porting everything was the answer to deeper bass but I then found that well-defined, articulate, acurate bass is more likely to be found in an sealed enclosure. This is one of those occasions where the proof is in the pudding of sweet, smooth, mmm-mmm good - sound.
Every once in a while I get a good deal on something and this was definitely one of those times. The other half of the time I get something I'm really disappointed with, or it's not as good as I had imagined it to be.
Most of the vintage equipment I own has deepened my understanding of what good audio can be. Combining old and new technology together has put excitement back into my love for music and sound. By the way anybody have a house I can borrow? I need a place to setup myhome theater!
Chris