HiVi B3S in mini transmission-line

[DocLorren]

This mini transmission-line design was published in the German journal Hobby Hifi in 2005. It seemed a fun idea to replicate this little loudspeaker (although I guess almost no-one built them concluding after searching various fora) so after reading the 3 inch full range test by John Zaph Krutke (www.zaphaudio.com) I decided to use the testwinner (the HiVi B3N not the –S- I like the looks better while the specs are more or less identical) in this enclosure. The filter design used is also John’s. I decided to internalize all small components only to mount the big inductor at the back.
Building time approximately 3 days (most of it sanding/veneering). Total cost under $100,-. So, how do they sound?
Pretty impressive taking into account the cost. Not any useful bass below 70-80 Hz but the midbass is surprsingly strong and impulsive. Compared to small Fostex drivers the mids are bit suppressed and lacking detail. Highs are clear and pleasing. This, however, is all preliminary since the drivers have been playing music for only ten hours and I have not yet fiddled with any damping behind the driver or vent.
This weekend I expect them to become completely finished with a little oil or wax on the veneer and some tweaking of positioning and damping.
Final comment, it is surprising how much juice these little drivers need: my regular AMP6 (www.41hz.com) is definitely underpowered; the alternative gainclone is a way better amp for this application. Although overall efficiency is low, the power handling is good; the gainclone drives them to sufficiently loud levels the AMP6 just cannot manage.

!Question for the guys with simulation software: how do the driver and enclosure match compared to the original Tangband W3-315SC design? I’m really interested in those sims but unfortunately have not yet the progs or experience to run them.

[DocLorren]

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[DocLorren]

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[DocLorren]

actually listening now and simultaneously drinking the brand from the previous post. Next week I'll come up with a more detailed listening impression.

[DocLorren]

last one showing internals

[Nanook]

and inexpensive too!

and juice will be required.

[gmilitano]

Nice work.

With small drivers, a chamfer behind driver should help out.

[kristleifur]

Congratulations, nice speakers! I've been looking for a similar design, it looks like. Thanks for the amping observations.

Is this the CC52 from Hobby Hi-Fi feb/march 2005? Here's lautsprechershop's kit:

http://www.lautsprechershop.de/hifi/.../tml_w3alu.htm

[DocLorren]

Yep that's the one. Thanks for the kind comments guys.