modest cost FR = best bowed bass & cello reproduction?

[freddi]

which enclosures (including OB) and drivers have given good success with well-recorded bowed bass viola and cello?

[v-bro]

I think you won't be disappointed with these...
http://www.visaton.de/de/testberichte/nobox/731.html

[freddi]

looks good - on ebay US, there were a pair of B200 with vastly different Re perhaps one was a 16 ohm version? - seller seemed (?) to imply poor quality control

with 2'x4' baffle and 12" wings for starters, briefly ran a 21" woofer biamped to 12" Eminence coax and wideband with 100hz highpass on 12" and 50hz lowpass on 21 - seemed like addition of a rear firing tweeter might be good. These Beta 12CX were out of spec with Qts higher than normal so would play on baffle all by theirselves. tried passive network too.

I've got some weak out of spec 50Hz 18" with Qts near 0.7 - maybe could be a start of a new 2-way baffle

http://img245.imageshack.us/img245/5923/obnwbe2.jpg

[v-bro]

That looks very good! Won't need much eq. probably...

Any idea of the sensitivity? Maybe still interesting with Visaton B200, but the difference in Re can hardly be very different due to quality control. I also suspect a 16 ohm version, but maybe there IS poor copper quality or a poor conducting part in the wiring. I wouldn't recommend them eitherway.

I've listened to the Nobox design once and it was mighty impressive live like sound coming from them! Very smooth, very low distortion, very realistic timbre to each instrument, very high efficiency...

Combined with good class D they must be really impressive...

[v-bro]

Originally posted by freddi
with 2'x4' baffle and 12" wings for starters, briefly ran a 21" woofer biamped to 12" Eminence coax and wideband with 100hz highpass on 12" and 50hz lowpass on 21 - seemed like addition of a rear firing tweeter might be good. These Beta 12CX were out of spec with Qts higher than normal so would play on baffle all by theirselves. tried passive network too.

Would seem like a good idea to give the 21" it's own amp with an R/C filter on the input, saves a lot on filter component cost and torture (as they will be in the line-level cable on the amp input the amp output will be connected to the driver by mere cable....)

Theory to calculate such a filter:
http://www.t-linespeakers.org/tech/f...ssiveHLxo.html

[freddi]

hi v-bro - - the 21" had 250W amp, 12" ~40W with 12dB slopes x21 seems ok

regarding x21 sensitivity - heres a rough indciator on the 2'x4' baffle outdoors without wings vs a small Karlson-coupler running a ~5% efficient 12 (and a nasty low Z LC "boost" network)

freddy

http://img451.imageshack.us/img451/8320/x21vk12aez8.jpg

[v-bro]

500uF? That's insane!

A good quality in this value must cost enough to get a mortgage on!

To filter this freq. with R/C I guess a 1uF cap with a 10K resistor would suffice...(guesstimated values...) Look up the price on that!

(That would give a 6db/oct. slope...).

I also guess the curve would show much better LF with a larger baffle.

Are you intending to use it outdoors, or is this your way of creating dead room for measuring...?

[v-bro]

Actually quite funny that 21" design is quite similar to the Nobox design
I posted right away (didn't have a clue..), don't you think?