DIY speakers using 32-liter cabinets

[phibes]

Hi Smurfette,
On the audax web site go to Produits, Prestige, Boomers/Medium and then Aerogel and you'll find the stats for the HM210Z12.
Cheers,
Keith
[PS] I'd consider upgrading the tweeter in this design as well. Have a look at the TWO25A16.........I've used it in a couple of other designs and it is a better performer than the TWO25MO.

[smurfette]

Thanks all for advice but now I have a better (?) idea. I'll build two subwoofers using my 32-liter cabinets. Then I shall put the subfoofers under my present 12-liter bass reflex speakers and make use of my unused active Sinus crossover which operates at 80 Hz. But what are the best 8'' woofers for subwoofer purposes?

[smurfette]

No, on second thoughts not a good idea...
If I can upgrade the tweeter from TW025M0 to TWO25A16,
why not upgrade to Morel MDT-37? Is there a reason for sticking to strictly Audax tweeters in KLS9?
Another idea: if I tweak the condensator value from 4 uF to 3.3 uF and the inductor value from 1.2 mH to 1 mH, the KLS9 xover cutoff frequency goes up from 3000 Hz to about 3700 Hz which will protect the tweeter better from low freqs at high power levels.

[sreten]

Curves for the new driver,

Port tuning of the 72 litre case appears to be critical.

For such a simple design as this the basic principle is :

The bass unit inductor is a compromise between reducing
baffle step and a reasonable crossover frequency, its a fine
line to tread, but high crossover frequencies are out.

Replacing the tweeter is possible but it must be carefully chosen,
its not as case of fitting the best tweeter you can find.
The series resistor needs adjusting to set levels and then the
capacitor possibly adjusting.

Good phase matching is claimed for the original crossover, you
don't want to mess about with this too much in a simple crossover.
You need a tweeter with a very similar impedance curve and
sensitivity if you want to maintain this.


sreten.

[smurfette]

I see. But is there still the following problem: at 3000 Hz or so the woofer has a narrow dispersion and the tweeter has a very wide dispersion which results in a mismatch - or is this something that the first order xover is capable of handling?

[sreten]

So called "off axis flaring" is an issue in many designs.

The general priniciple is that the on axis response is
reduced somewhat to compensate, to give a flatter
overall room response.

Dual concentrics suffer less from this problem, as do
tweeters placed in a flare. Lowering the c/o frequency
also tends to reduce the problem.

Simply put - for simple designs it cannot be fixed -
only compensated for - but simple designs can have
other advantages over more complex designs where
off axis flaring is less of a problem.

sreten.

[smurfette]

Hmmm...
I have also another pair of cabinets, with drivers and all, built in the 70's but no longer in working order. These cabinets are huge in volume and the front baffle is quite wide . They were originally used in a closed 4-way system that sounded awesome at the time but the drivers have deteriorated.
Is someone aware of a design, perhaps closed-box 3-way, that I could succesfully copy? Must come down to about 23 Hz since I have quite a few organ records.
The 12'' Peerless XLS woofer would sound nice in these cabinets.

[sreten]

suggest a new thread with more details for this,
size, what works, what doesn't, crossover details etc.
(The XLS is designed for compact cabinets)

sreten.