12" full range. help needed

[superfunk]

Hi all. That's my first post here, so be nice please.
I won an auction on e-pay for a pair of 12" Visaton


now i need to put them into some nice shaped boxes...

i wish on a good performance from around 35Hz to 20KHz (if it can go lower, i surely won't moan).
I'm not worried about WAF, i live alone in a tiny
High SPL are not needed, but they're always welcome.
The tiny room is 3,5 x 5,5 metres x 2,60 tall.

Last weekend i went to an audio convention (if that's the right word) and had the chance to listen at different systems.
I was very impressed by two Systems: one with "Avantgarde Solo" and the other with two set from "Horn Manufaktur"
the models were these two:
A90 - diffusori a tromba audiophile
A100 - diffusori a tromba audiophile
As you know, the Avantgarde has a bass reflex on it's back and uses a specifically designed built-in amplifier, with a moulded frequency responce, so this is not possible for me to build
The other two speakers are backloaded horns, but they use their own drivers.
Do you think it's possible doing something similar with the 12" Visaton?
I like the Dallas 2 design a lot, but they're for 8".
Is there a nice folded horn to accomodate a 12" driver? any suggestions?
I would also consider Onken as second choice, but i don't know much about them. Bass reflex is simply not my cup of tea.
Thanks in advance.

[mashaffer]

Will need to know the specs (fs, Qts, Vas at a minimum)

[superfunk]

Hi, this is what the seller wrote on the auction page:

30 cm in diameter
8 ohms
100 watts RMS
40 Hz Resonant Freq.
Eq. Volume 180 VAS (liters)
0.68 Qts

this is from the visaton website:

fs Qms Qes Qts Vas Sd Mms B xl L
40Hz 3.59 0.84 0.68 180l 511cm ² 33g 8.2Tm 1mH

[Glowbug]

With a Qts that high, open baffle might be something to look into

[superfunk]

Originally Posted by Glowbug

With a Qts that high, open baffle might be something to look into

Oh no, so i bought the wrong stuff...
There is something unconvincing (to me) about open baffles...
and, if not said before, i prefere avoiding the bass reflex boxes. i just don't like them too much and wish to try something different.
If a "classic" backloaded horn is not a good thing with these, what about a "vott-style" or even a "tannoy wannabe" onken enclousure.
The problem is i don't know much about both.
If the high frequencies won't be convincing, i will play with a supertweeter, just to add some fun and learn something new.
Any suggestions on something to make them sound good?

[mashaffer]

Hmm... Qts like that could be used for a largish sealed box but with a 6.4 ft^3 Vas it would be a substantially largish box. You might be able to go aperiodic. On the other hand since you were thinking horns then a big box is apparently not a deal breaker.

Hear is another thought. Maybe you can try a transmission line. The Vas again will probably rule out really small but maybe...

What bothers you about OB? That Q is actually on the bottom end of what I consider appropriate for FR OB but the fairly low fs probably makes up for it to some degree.

[GM]

Originally Posted by superfunk

i wish on a good performance from around 35Hz to 20KHz (if it can go lower, i surely won't moan).

Is there a nice folded horn to accomodate a 12" driver? any suggestions?
I would also consider Onken as second choice, but i don't know much about them. Bass reflex is simply not my cup of tea.

Greets!

For my records, which model Visaton is this?

Anyway, getting ~flat down to 35 Hz with a 40 Hz Fs, relatively high Vas, Qts driver = huge, like ~540 L for an Onken, which BTW is a bass reflex.

BLHs are designed to load the BW below the driver's mass corner (~2*Fs/Qes), so it wants a horn that only loads below ~95 Hz, i.e. your room isn't big enough for two horns that start with a throat area the size of a 15" driver. Even a relatively 'small' TL is 340+ L.

Really, to get a theoretically good performance out of them in a relatively small cab (< Vas) requires a well damped bass reflex, but it will have a relatively high F3.

GM

[superfunk]

thanks for the replies.

For my records, which model Visaton is this?

Visaton FR31NG 8ohm.
Don't know if it's a good driver or not... i just bought it to start experimenting this stuff. I paid 70euro for the pair, shipping included. nothing so painful.

i wish on a good performance from around 35Hz to 20KHz

Forgot to say: on the box it's wrote f^3-15KHz, so i may add up a supertweeter in the future. (or change the whole thing)

Really, to get a theoretically good performance out of them in a relatively small cab (< Vas) requires a well damped bass reflex, but it will have a relatively high F3.

Do you consider the onken a good idea? it really temptes me, because if i like it, i could think to get a 12" coax tannoy for the future, or something more hifi.

What bothers you about OB?

I have the suspect that they sound "light". i'd like that pounchy feel out from a kick drum... i've only heard a OB in my life, it was lovely, but nothing special (to my ears).

Anyway, i've discovered last night the sigle PA on the box.
Maybe this thing is not going to sound any magic, but my initial thoughts were to find a good enclousure, taste it and then see if it's worth getting a great driver.
If you think a onken can be used with good results, can you put me in the direction of the design? does exists a calculator to draw the litres needed and things?
should i completely discard the idea of a BLH?

[superfunk]

up... i need help.
am i better to discard the idea of a BLH?
is it a good idea a onken?

[freddi]

if it has a clear midrange and treble then it should play reasonably well in the original Karlson 15" enclosure with the driver centered on an adapter board. I've used EV SP15B in K15 and their Q was >1.