Passive Crossover for Passive Subwoofer?

[Toast_Master]

Hey

Is it possible to design a passive crossover to a subwoofer that has a different orders in it...for example I want to make a passive crossover that has a 2nd order highpass @ 18hz and a 4th order low pass @ 80hz

I know its possible to make them the same for example a 2nd order bandpass at 18hz and 80hz?

If any more info in required just ask

any responce to this would be appreciated or even a referal as this is a complicated subject

Thanks

 

[pinkmouse]

It is possible, but the cost, size and weight of the huge inductors and caps required would be very large, possibly more than the cost of the rest of the driver and cabinet put together. It may seem complicated, but active is the way to go with subs.

 

[sreten]

Hi,

I'll second PM, the inductor for a 18Hz highpass will be extraordinarily expensive,
if you could even find one, the 80Hz components will also be expensive.

Active highpass (and lowpass) is the only sensible option.

There is no problem with 2nd order highpass and 4th order lowpass.

/sreten.

 

[Toast_Master]

as in active crossover or active subwoofer?

 

[Toast_Master]

I know how active crossovers work and that they are more efficent and make the amp more efficent which makes less distortion but i dont know how to make them.

Can any of you direct me to a book or site or even a store bought one that could me make them or buy them

thanks

 

[Toast_Master]

sorry for all the mis aligned posts due to me reading your answers before youve seen my "under moderation post"

 

[Toast_Master]

Well...? any info at all?

 

[Khron]

http://sound.westhost.com/project09.htm

I'm in the process of building a couple of active crossovers as seen in the link above. If you're interested, i might even attach the schematic and PCB as i drew them up in Eagle 4.03.

 

[Toast_Master]

Could I pay possibly pay you to design and/or make one for me

(with my predetermined specs that ill tell you if you accept),

or could you direct me something that can

please!

nothing comes up on google anywhere that I can use

and I cant use yours cause there for speakers and 2/3 way ones..I want a 1 way bandpass if that possible

Thanks

 

[rabbitz]

Have a look at Jaycar sub processor kit KA1814 or Altronics sub controller K5562 and should cover your needs.

A plate amp is still be easiest option but if you want to use an existing power amp, then use either of the above kits.

 

[lndm]

There used to be a kit for use with Electronics Australia's Playmaster series. IIRC, it had three op amps and gave stereo hp outputs, a mono sub output, and came with instructions for adjusting crossover frequencies. Jaycar don't seem to have it, must be Dick Smith.

 

[Khron]

I guess i could draw up something you could use, just tell me exactly what you need...

E-mail me, i think it's gonna be a bit easier than through here

 

[David Gatti]

Here's my active subwoofer using Marchand low pass filters,

http://www.gattiweb.com/samson_design.html

http://www.marchandelec.com/

I can also give you a hand if needed.

 

[Toast_Master]

If I were to get one of these: which would be better? IF

http://www.altronics.com.au/index.asp?area=item&id=K5562

http://www.jaycar.com.au/productVie...d2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

I feel that the altronics one is better..but it dosent specify what its high pass is

also does bypassable mean that you can turn it on and off?

 

[Khron]

I'm not sure whether the altronics HAS a high-pass rumble filter. But, apart from that, it does look better than the Jaycar kit (except you need an extra PSU of some sort).

 

[Toast_Master]

yes the altronics looks way better and I like it more but...the jaycar one has a rumble filter at 20hz 2nd order, could I change a certain thing on it to make it 18hz? cause if so then my search is over

 

[Toast_Master]

David Gatti could you please give me your email so I can contact you about active corssover help as well?

thanks

 

[lndm]

could I change a certain thing on it to make it 18hz? cause if so then my search is over

Yes you could. This is a silicon chip design and AFAIK such kits come with the original article which means you will get a schematic and detailed explaination and instructions. Even if it does not tell you how to make the exact change you want, you should have plenty of info with which to work it out.

 

[Toast_Master]

thanks for help

would it be an easy change though? would I have to change many things because changing one value would change the effects all the other components have on the crossover

so the actual kit may come with an instruction book saying other modifactions that you can do?

 

[Toast_Master]

Also..should siganl to noise ratio be taken into account?....is higher better?...because the altronics one is -84 Db @ 300mV

when i normally see it written like this...for eg Z-5500:

95 Db (100 typical)

can someone say somthing on this?

thanks