Vendor guidelines - Peerless:

Based on my respondents, all of Peerless' woofers, subwoofers, and mid/bass units - and especially the CSC and CSX lines - can be recommended. All you need to do is to check the curves and numbers to determine which units will work best in your planned project. Some drivers worthy of special consideration include:

1. The 830500 12" XLS woofer. The "XLS" designates a new series of extremely long stroke woofers. Featuring an extremely wide and compliant surround, Nomex^TM cone, and an excellent motor, these have been recommended by several people. With a quite low Qts value (0.20), it's only suited for use in small vented or PR enclosures. Most who've used it have had success using its matching 830548 12", 425 gram PR (see Section 13 for more PR information) in a 40  liter (1.41 cu.ft.) box. This yields an alignment with F3=45 Hz and F10=20 Hz.
2. The 831857 12" subwoofer. Part of the CC line, this unit offers one of the most attractive balances between price and performance in the crowded 12" subwoofer market. It's especially attractive for those who might shy away from the Swan 305 (see below) due to the latter's use of a foam surround. Used in a 6.5 cu.ft. vented enclosure, this driver can put out 15 dB more acoustic energy at 20 Hz than an NHT 1259 (see also) in a 3.3 cu.ft. sealed enclosure.  view 
3. The 830452 10" XLS woofer. With a very low Qts value (0.17), it's only suited for use in small vented or PR enclosures. Most who've used it have had success using its matching 830481 10", 400 gram PR in a 35  liter (1.24 cu.ft.) box. This yields an EBS alignment (see discussion of enclosure types in the Introduction above) with F3=78 Hz, but which is only 7 dB down at 20 Hz.
4. The 850146 10" CSX woofer. Usable in sealed or vented enclosures, this unit combines great FR with some exceptional numbers (Xmax = 9 mm., Fs = 22 Hz) for an affordable 10" woofer.
5. The 850136 8" CSX woofer. Even flatter FR than the 850146. There aren't as many good 8" woofers as there used to be - this is one of them. Obviously, not as much bass, but an even better bargain.  view 
6. The 850490 8" HDS woofer. Even smoother FR than the 850136. With its "aerodynamic" cast frame and advanced sandwich cone, this is the next step up - in both sonic quality and cost - from the 850136.  view   response 
7. The 830411 8" 8" woofer. Although it lacks the high-tech cone materials of the CSC and CSX models, this is the best value in 8" woofers - and with quite decent performance to boot. Suitable only for sealed boxes, apparently only Madisound carries this driver in North America, but it sells it for only $29.
8. The 850118 7" CSC woofer - actually a mid/bass driver. This unit features flat FR within 1 dB from 70 Hz out to 2 kHz. It's also a best buy in the crowded 7" mid/bass field.  view 
9. The 850439 6.5" HDS mid/bass looks to be a major new star in the crowded 6.5" mid/bass market. One of these has already found its way into one DIY system, mated with a Hiquphon OWI, and described as "a [Scan-Speak] killer".  front view   side view   response 
10. The 850122 6.5" CSX mid/bass. There's a lot of competition in mid/bass drivers from 5.5" to 7" diameter. The 850122 offer exceptional FR curves, good numbers, and an affordable price.  view 
11. The 850108 5.5" CSX woofer - actually a mid/bass driver. This affordable unit is flat within 2 dB from 100 Hz to beyond 3 kHz. Roll offs at either end are smooth and well-behaved. Predecessor to the 850488 driver (see below), the 850108 offers a lower Fs value, albeit with lower Xmax as well.  view   response 
12. The 850488 5.5" HDS mid/bass follows the considerable success of its pre-HDS predecessor, the 850108 - all at an even lower cost! Roll offs at either end are even smoother and well-behaved than the 850108. This unit competes head-to-head with the equally outstanding and highly regarded Vifa P13WH-00-08 for midrange applications. All 85108 comments apply.  view   response 
13. The 821615 4.5" midrange features a PP cone and an integral housing, eliminating the need for a separate midrange enclosure. On-axis response is ruler-flat from just above its 530 Hz Fs out to 5 kHz. Off-axis response isn't as good, but still looks usable out to about 3 kHz.  view 
14. The 811815 1" tweeter features a soft fabric dome and a controlled directivity faceplate (i.e. a shallow horn). On-axis response is quite flat from 2 kHz all the out to 20 kHz, albeit with a broad, shallow (~1.5 dB) dip in the 5-10 kHz range. Off-axis response is very good out to about 10 kHz. This is the same tweeter used in the well-reviewed Meadowlark Kestral system.  view   response   distortion   waterfall 
15. The 811830 1" tweeter is virtually identical to the 811815 in most respects. The difference (other than a $1 higher price) is that the 811830 uses ferrofluid and has a coil/motor assembly specially deisgned for higher power and lower power compression. Most 811815 comments also apply to the 811830, except that the 811830 has a higher value of Fs - apparently the price of the higher power handling.  view   response