Generic Sub Crossover Suggestions?

[Dominick22]

I tried finding the specs for the Martin Logan subwoofers used in the Descent, but no luck. I even called the company and of course, they said all the info was proprietary.

Anyway, I have already built an amp (although it is only pushing around 100 watts) and now, I am just looking to build a crossover that will cut off around 80 hz.
Since I dont have the speaker specs, I just need a generic crossover to start with and then I can tune it by ear. Since I am new to crossovers, I am not sure which values would be on the safer side of experimentation.

Some ideas or even schematics would be great...

Thanks,
Dominick

 

[Dominick22]

Bump

Some help please!

Dominick

 

[mikee55]

Hello

Hi there, Take it you asked the Google, and searched as hard as you can? Its not easy, is it?

The Elliott Sound Products site has shed loads of info on all things hi-fi.Did you go there? He's got a great article on xovers.

Others, chime in please....

http://sound.westhost.com/index.html

 

[Cal Weldon]

If you want an 80Hz XO can you not build that into the amp?

The size of the components needed for a 24 dB passive will be cost prohibitive.

 

[Dominick22]

Cost prohibitive--how so? I cant imagine costing more than $50, but I would be willing to spend up to $100.

Dominick

 

[Dominick22]

OK,

Check out what I found. This calulator works pretty good I think. I wanted to see what others thought.

Anyway, I am not actually using a tweeter. I am trying to build a filter for just a sub. Would the adjustment in the case be as easy as removing the tweeter from the digragm? Or would that change the values of the resistor and capacitor?

http://www.lalena.com/audio/calculator/xover/

Thanks,
Dominick

 

[Dominick22]

If I wire these in series:

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=255-840

Will I effectively arrive at a 24mH Inductor?

Dominick

By the way, I appreciate the help offered by my fellow DIYer's!

 

[Ken L]

I just need a generic crossover to start with and then I can tune it by ear

To get it right, will take quite a bit of time money and energy.

IMHO, Cal is right in trying to point you in a different direction


80hz is pretty low and hard to hit with accuracy, gonna be expensive and big,

Most people crossing that low use some form of passive, line level crossing and bi-amp.

You might do well to consider that approach.

Marchand, I know offers passive line-level crossovers - should be some where around $100 ro $150 IIRC.

Generally, it has been my experience that when you get beneath 100 hz, the steeper the slopes the better.

 

[pinkmouse]

Have a look at in car active crossovers. They are pretty cheap, and well sound much better than anything passive you could make up.

 

[Dominick22]

Thanks guys...I will have a look!

Dominick