I've just seen the pdf; other than needing a minor text change on the sketches (somebody changed what I wrote without realising they changed it to something incorrect) it's good to go.
Re sealed box, as ever, it depends on what alignment you want. Assuming about 1/4 ohm series R for wire, connectors &c. and a voltage source amplifier, Butterworth is about 12.5 litres, Fb 75Hz [nearly]. With 0.5ohm series R, which is probably more representative for the majority of people with wideband drivers who don't go to extremes with wire and have a regular voltage source amplifier, call it 13.5 litres for Butterworth with Fb dropping about 2Hz. If you use single-strand 24ga as Dave favours for e.g., then a loop length of 6m / 19.68ft provides about 1ohm [nearly] series R, and assuming same voltage source amplifier Butterworth is about 17.5 litres, Fb 69Hz [nearly].
I don't necessarily favour maximally flat Butterworth alignments, but it serves as a standard baseline.
Alpair 5.2/3, 7/11ms are the spiderless drivers. The original 5/Jordan J6T is also spiderless but have ferrofluid.
dave
Scott sent me the preliminary spec sheet (and i have some drawing work to do before its release) but preliminary models indicate the the optimum Mar-Ken will be 25-30 litres (with est (F6 in high 30s, F10 in th elow 30s). That puts extention in the same sort of range as the A12pw, really quite good. And as small as 9 litres should be doable, maybe smaller.
I’ll have to get Scott to see how well it goes into Joan instead of FHXL.
dave
I’ll have to get Scott to see how well it goes into Joan instead of FHXL.
dave
Extension and gain, basically, since the CHN110 tends to give its best when it has room to breath. Joan F6 = about 34Hz (anechoic). FHXL F6 = about 44Hz (anechoic). The latter alignment is fine, it's just that you can get more out of it if you have the volume. FHXL does have a slightly faster acoustic low pass though. Not a massive deal, they're both decent, it's just got a slight edge in this regard. Swings & roundabouts.
The larger enclosure has a slightly wider operating BW with this driver, so consequently GD will be a little greater in the 300Hz region (the audibility of GD being a function of time & frequency). It is still reasonably effective (more so than some), so this should be a non issue for most people interested in building them. You pays your money, you takes your choice.
