Focal Audiom and other stories...

[esl]

Well,

Finally I decided to take up another project of
DIY speakers. Reading different datasheets and bearing in mind
the budget for the drivers alone (1 K USD, maybe a little more),
the fact that my room is 32 sq meters and my goals (high
efficiency, alive sound with fast dynamic swings, high resolution
and fast, authoritative bass) this is what I decided:

- due to the fact that my room is 32 sq meters, only 3 way
will make do. Good midwooferes are generally to small to produce
considerable amounts of deep, dynamic dass and at the same
time to heavy (Mmd) to render midrange of high resolution.
So we have first assumption - it must be 3-way.

- lest's start from the bottom: I want bass reaching down to 30
Hz with utter controll and pretty good sensitivity... what would
be your choices for a 12" woofer?
I've been thinking about Peerless XLS 12 or maybe something
else, but the choice can be really difficult due to the fact that,
despite there's a plethora of specialized subwoofer-units (high
Xmax, low SPL), only few drivers match my criteria.
These drivers are: mentioned Peerless XLS 12, Eton 11-581
(however I don't know whether wouldn't it be to small 4 my room). Any ideas here?

- as for midrange drivers I consider using the Focal Audiom 6 WM
Sandwich-W midrange. It looks good on paper, has high SPL and
low Mmd. Anyone can comment on this driver? Anyone heard it?
The Freq charts looks strange, anyone could comment on that?

Thanks,

esl

 

[sreten]

Pure volume is dependent on m cubed not squared.

Given your m squared = floor area the first thing to ascertain
are your room modes = 1/2 wave length of dimensions.

These are critical, ideally you want ~4.5m x ~7m.

These give room modes of ~37Hz and ~24Hz.
Port tuning should be the geometric mean.

This suggests you should have bass reflex speakers
tuned to ~30Hz, in room cutoff will be the 24Hz mode.

I like overdamped reflex aligments to suit room gain, typically
detuning the port by root 2, this impliies a maximally flat port
tuning of ~42Hz, detuned to 30Hz.

I'd suggest you have loads of choice to meet this criteria.

sreten.

 

[esl]

Hello, my room modes are:
28 Hz (strongest), 34 Hz (less audible) and 46 Hz (floor - ceiling).
So I assume that I'd have to avoid tuning the BR port to 34 Hz.

Yes, there's quite a plethora of choices. Well to Eton and Peerless,
I can also add Visaton TIW 360. Strong magnet, celulosse cone,
looks promising:

http://www.visaton.de/deutsch/artikel/art_405.htm

What do you think?

esl