Seas Exotic in a TQWT

[talaerts]

Hi all,

FYI

Udo Wohlgemuth of Intertechnik, the German distributor of Seas and others, regularly publishes DIY designs. I just found out that he recently did one featuring the highly regarded SEAS F8 full range driver. For this design he used the 4 ohm variant. He wanted a box of reasonable size with better bass than the closed box design proposal by SEAS, smaller than the optimal 200 litres BR, and less complex and big than a horn. Hence the TQWT.
Full write up in German, plenty of construction pics and plan are at:

Simply Exotic | Lautsprecherbau

I like the visual style resulting from using nice wooden (or veneered) side panels and black MDF in the middle.

He also applied various corrections to the speaker's response, to get it more flat. Unfortunately the R L C values are not published, you get them if you order the full kit from them - I can understand that but it's a pity if you live outside Germany.

[GM]

Looks nice, but being a vented TQWT [ML-TQWT], I would personally just use a ~99 L MLTL tuned to Fs to keep damping to a minimum.

GM

[von.ah]

That is quite a filter they employ...

[talaerts]

Well, they flatten the upwards slope of the response and tackle the 3 biggest remaining peaks.
Personally I wonder if flattening the response isn't good enough.

[MiiB]

Sucktion always sucks, as the posistion of the resonance peaks wanders with amplitude. So what you target at 90 dB is totally differnt at 93 dB. The gentile rise you'll have to target, the resonances are there regardless. Those you'll have to live with, thing is that the unit will generate them under transient load regardless of the filter trying to notch them out or not....

[Bob Brines]

Originally Posted by von.ah

That is quite a filter they employ...

It's just a BSC, three traps and a zobel. How simple can you get?

Seriously, with a peak in the middle of the sibilance range, at least one of the traps is probably a good idea.

Bob