Peerless 830843 sub as a woofer in 3 way

[Francec]

Being very much a learner in this game, I looke at the specs of many woofers for use in an active 3 way system. The bass for most seemed lacking and while looking at sub-woofers, the question came up; why not use a sub-woofer in lieu.

The drivers I am interested in are;
Peerless 830843
Datasheet Used with a 54-55 litre closed box, there is good bass according to WinISD.

Vifa PL11MH-09-08 bass / midrange
Datasheet

Current VIFA tweeter until something strikes my fancy.

The 830843 seems to have enough response for a crossover at 300-320 HZ which the mid-range is comfortable with. High pass will be 3000-3200Hz. Being active, matching sensitivities isn't an issue.
My question; is my logic sound or is there something that won't make it work?

Frank

[sreten]

Hi,

There is nothing stopping it working with the corrrect active c/o
that produce the correct acoustic responses and roll-offs for
each driver, these will not be "standard" active filter functions.

/sreten.

http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spk...esigningXO.htm

http://www.zaphaudio.com/
http://www.rjbaudio.com/projects.html
http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm
http://www.humblehomemadehifi.com/
http://htguide.com/forum/forumdisplay.php4?f=39

http://www.linkwitzlab.com/
http://www.geocities.com/kreskovs/John1.html

[Francec]

I should have been clearer. The active cross-over is 24 dB per octave.

Frank

[sreten]

Originally posted by Francec
I should have been clearer. The active cross-over is 24 dB per octave.
Frank

Hi,

It does not work like that. Standard filter functions with no EQ
rarely work well. Proper active filters are the target filter minus
the acoustic irregularities and roll offs such that the acoustic
response meets the wanted target, e.g. 4th order L/R.

You can include standard filters in modelling but your results
will not follow the standard filter functions. Minimum "extra"
to add would likely be some passive line level EQ for shaping.

Using 4th order L/R electronic and matching drivers levels
is a short cut to some form of adequate, it is not "correct".

/sreten.

[Francec]

Hi sreten and thanks,
This is the crossover I will be using; Rod Elliott's L/R crossover which is, I believe, fourth order, has an adjustable output buffer.

Having looked around a bit more, I'm now tending to the Visaton TIW 250 XS 8 OHM Data page in a 55 litre vented box as per the web page. All the design work is done .

Frank

[tinitus]

Regarding you first suggestion, a peerless sub
I would look closer at XXLS 12" 830952, that one hits 20hz with ease, but needs a big box
Fore higher midbass your Visaton choice probably works better

[Francec]

Thanks tinitus,
12" is too big for the size box in a fairly small room. I don't think that I could get it past my wife either.

Frank

[sreten]

Originally posted by Francec
Hi sreten and thanks,
This is the crossover I will be using; Rod Elliott's L/R crossover
which is, I believe, fourth order, has an adjustable output buffer.
Frank

Hi,

It is not the proper way to do it.
See Linkwitz's and Kreskovsky's stuff on
active XO's in the links I previously posted.

/sreten.

[qwad]

the other alternative is trade the wife in for something more agreeable
cheers chutzpah

[Francec]

It is not the proper way to do it.

It may not be but, nonetheless, it works extremely well!!!!.
The current setup is:
Tweeter Vifa D25TG-55 1" dome
Midrange Peerless 832873 5 1/4"
Woofer Peerless 830868 8"

The difference over the passive setup is chalk and cheese.

Frank