Looking at some readily available speakers and some have been fairly received. Looking at the offerings from Dayton, the T652s ($157-$170) and the MK442T ($268), I was already thinking of what was available to work for a TMM design.
I was thinking of a slim style tower design, so whatever driver was chosen would mean the tower would be at least 1″ (2.54 cm) on either side, so driver + 2″ (5.08 cm). I had already looked at those 6-1/2″ drivers, but the box needed would be too big. Most 4″ drivers didn’t go low enough or have enough SPL in the useful range. Then I split the difference and started with 5″ drivers.
Came up with the Visaton W130S-4 and W130S-8 5″ drivers. The -4 WAS on sale for $19, but is no longer available. The -8 goes for $30.59 and is in stock. Ran rough #’s in my Qbasic and I get about a 1.5 CuFt box for the drivers in a compound configuration with FB of 43Hz and F3 of 39 Hz. Not a bad size for a tower with decent bottom and SPL.
Threw them both in WinISD and worked a 1.75 CuFt box with a 1.1″ x 7″ port tuned to 39 Hz and an F3 of 35 Hz for both the -4 and -8.
Thing is, the 5″ will start beaming at about 2700 Hz, and most tweeters have a hard time hitting that for a crossover point. Enter the Peerless by Tymphany XT25TG30-04 1″ Dual Ring Radiator Tweeter going for $28.47. FS is 436 Hz, so a crossover at 900-1000 Hz is quite comfortable for both.
I would have liked the -4’s since putting them in Series would have pumped the SPL up to about the level of the tweeter, ~ 89 dB, whereas the -8’s in parallel will drop down to ~ 84 dB. Hmm, wonder if I go through the #’s and put the drivers in as 1 total at 16 ohm, what that’d do… HexiBase’s video helps explain all that.
Anyway, keeping my mind active. Have lots of other things going still. What do you all think?