For anyone stumbling across this ancient thread and looking for information on Sapphire speakers, I have some experience of my own to convey, just in case you are looking at a purchase of used equipment like mine.
From Craigslist I purchased a set of 'The Speaker Company' TST3s with a TC2 center speaker and a pair of TSS surrounds plus T250 sub for $300.
Sapphire got sold to D&M and was milked as a cash cow along with a few other spun-off speaker lines from Polk and Energy apparently for a couple of years with a couple D&M in-house designs added to the lines.
I picked Sapphire/TSC based on my listening test and the price that was IMO nearly unbeatable at today's used prices.
The original design/marketing of Sapphire was done by Cary Christy, a founder of Infinity, and Tom DeVesto of Cambridge Audio. Tweeter Etc. invested heavily and sold the line as a sort of in-house model until they folded and D&M took over with TSC rebadged line.
Overall the Sapphire sound is good, especially at current used prices (resale value is the pits) so if you only care about sound they are a great value but there are some caveats, especially with budget lines like Primus competing, with more modern technology and world labor markets driving prices down.
Compared to the very forward-sounding midrange of Primus 3-way towers, the Sapphires are very laid-back almost to a fault but very smooth with none of the (minor) Primus fatigue factor I experienced. The bass of the Sapphires is superior to Primus IMO. The Sapphire center speaker is a dog compared to the Primus, and even compared to the Sapphire towers, so you might need to get creative for optimal surround sound.
Also, these Sapphire speakers were manufactured 5-10 years ago but so far the rubber surrounds and plastic domes seem OK. The plastic grommets that the metal grill posts sit in have loosened up but a single layer of cellophane tape on the posts seems to fix it. Crossovers may have issues from perhaps capacitor plague (rumors of reliability issues with the original Sapphire line pre-MKII models maybe). Many used Sapphire towers are missing the (broken) plastic outriggers and spikes with ball tip so you might have to construct something or buy aftermarket. I used a single 12" length of 1"x3/16" flat steel bar with chrome screw-in chair gliders in tapped holes. You will need two such outriggers, or as I used, one outrigger plus a spike, per cabinet for adjusting the height of the rear and may have to order scarce 7mm metric bolts to hold the bar on the front. I also recommend a drill press since hand drilling was exhausting.
The rear ported TST3 towers (Sapphire model ST3) have an airy clear laid-back sound to them and plenty of bass down to at least 30Hz when positioned for stereo (surround crossover could vary up to 100Hz depending on placement and subwoofer). Rated bass extension is 20Hz but IMO that is an exaggeration.
The 8" soft aluminum woofers might go into breakup near crossover at high volume esp. the 5.25" mids in the vertical MTM array too but I have not noticed any such tendency at the modest levels I use.
Since I am older and have brick-wall hearing loss at 12KHz I really cannot comment on the 1" polycell tweeters except to state that I notice no issues and neither has anyone else who listened to mine including my adult children with better ears. Infinity used the same tweeters in some of their popular older designs. The cabinets are minimally braced but I notice no resonances so apparently the crossovers keep the drivers from stimulating any residual resonances from shorter unbraced portions of the side panels.
The ST2/TST2 also sound great and are very similar design with one coated 10" paper woofer instead of 2 8" metal woofers and the identical 5.25"/1" vertical MTM array. Usable bass extension to ~35Hz. I am now using a pair of them as my front l/r.
The ST1/TST1 are similar to the ST2/TST2 except for the removal of one midrange and the use of a single coated paper 8" woofer. Usable bass extension to ~40Hz. Removing one M from the MTM array means the vertical dispersion is not so controlled so these are better suited to smallish room but they still sound very good. I installed a set of 4 for my son to use with his gaming along with an SC center speaker. ~$500 for the set of 5 in nearly new condition and they are small enough to not dominate the room. Added a used Mirage Omni S12 sub to go with them for $100 plus one more SC for $40 as the rear in a 6.1.
The T250 subwoofer that came with my first 5.1 set of TSC is adds little bass extension to these towers but works great for smaller setup in bedroom. I have no idea if there is an equivalent Sapphire subwoofer model or not but I can state that for a tiny 10" ported sub it sounds really really smooth and not boomy at all. The custom plate amp failed on first use so I had to replace it with a similar BASH and that meant adding adapter shims since the dimensions changed slightly.
The sealed enclosure wall-hanging TSS dipoles (Sapphire model SS) have only one woofer and as such are not exactly traditional nor do they enhance ambiance much for someone with my hearing loss. They are also a pain to bungee onto stands and topple off shelves or tables quite easily unless secured. They only have two teardrop screw slots one above the other for mounting. I tried an additional set of Sapphire SS rear surrounds for 7.1 and noticed the surround sound stage was open but muddled in the rear. One of the SS dipoles has a bright-sounding woofer so I suppose that it may have a failed capacitor in the crossover. The dipoles are out of the system now and replaced with 4 ST3/TST3's.
The TC2 center speaker has a poor design IMO with widely spaced horizontal WTW array (the waveguide on the tweeter is huge), large boomy rear ported cabinet with no bracing and tweeter equalization completely wrong, padded way down with no 'snap' on the calibration sweeps. The mismatch between the center and the rest of the system is stunning. I compared it to the original Sapphire SC in my son's system and found that 'The Speaker Company' shortened the depth of the TC2 cabinet by 2 inches (is that where the '2' came from?) as well as maybe tweaked the crossover to reduce the tweeter output. I did not look at the crossover to confirm but the tweeter definitely sounds quieter so it could be a failed component too I suppose but I did swap tweeters and the tweeter is good. The smaller TC2 rear ported cabinet seems even more boomy than the original SC and dialog is terrible. IMO the complaints on the sound of the Sapphire/TSC line can be attributed to the IMO markedly inferior center speaker design.
Regardless, the original SC design also matches the towers poorly and both SC/TC2 designs sound boomy in a cabinet or between shelves plus they exhibit prominent sound of combing and lobing in horizontal axis. My recommendation: forget the Sapphire center speaker models and use an SB (5.25" woofer) or SBL (6" woofer) bookshelf model or a tower for your center. If that fails you, use a SAT1500/TSAT2000 WTW center speaker instead but be aware the efficiency and power handling are low plus it still sounds slightly boomy and thin compared to the towers. I used one for months and it sounded OK if not great.
I contemplated a custom horizontal WMTMW design (similar to the Primus) using the 5.25" woofer, the 3" woofer/mid from the line of satellites, and the .75" tweeter from the satellites, but due to cost/complexity of constructing a cabinet and tuning the crossover have not done so for such a budget endeavor.
I subsequently upgraded to 11.1 and used the SB for wides and center plus the SBS for heights. The SB sounds great and is occasionally advertised for ~$100 a pair, very similar sound to the ST1 towers.
The SBS with paper woofer and smaller/lighter enclosure sounds less great but OK and has the same 3/4" tweeter as the on-wall satellite speakers SAT1000/TSAT1000 and SAT1500/TSAT2000 that sound great for what they are, again especially at today's used pricing.
I bought full 7 speaker set with 3 of the 3"/.75" WTW SAT1500 and 4 of the WT SAT1000 for $200 plus shipping and installed them in the bedroom with the T250. Much less combing and lobing in these smaller WTW plus they are small enough to orient vertically.
OK that is everything people, if you stumble across Sapphire/TSC and get bitten by the audiophile bug but have to do it on a budget, now you know what the trailblazer found out along the way.