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DIY FB1i anyone?

PigletsDad said:
I don't think you do, he has downloadable software (Mathcad workbooks) that he sells that contain all his formulas and design tools.

Also, he has published lots of documents with useful stuff, and these are available without charge.
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Thats great. I have no idea what a Mathcad work book is though (I know what auto cad is)! Can anyone enlighten me?

Cheers, Mike
 
Congratulations on the new arrival Mike! One good thing with tall speakers is that the drivers will be out of reach of questing little fingers ..... at least for a while!

Dan
 
The M17WH-09-08 have pros and cons in my RTL's. Midrange is too forward and bass level is too low, although it is nice bass. I like the sound of them and I reckon in the right box and on a carefully designed xo they could sound really good. Anyway, I'll be selling them on, or swapping for a pair of WG's if I can.
 
mikesnowdon said:
Thats great. I have no idea what a Mathcad work book is though (I know what auto cad is)! Can anyone enlighten me?

Cheers, Mike
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It is a bit like a spreadsheet on steroids; you type a few numbers about your driver and box in, and masses of calculations happen, graphs are drawn and so on.

Mathcad is a mathematics and graphing package. A workbook is file for Mathcad with some calculations and so in it.

There is a free viewer for the workbooks that MJK links to, which lets you use his design tools, but wouldn't allow you to develop new workbooks.
 
Sounds good.

My freind is drawing up the Cabinet plans as I write this. It should be ready by tomorrow. I will have individual drawings of each panel also. If anyone is interested dont hesitate to PM me your email address.

Mike
 
Sparts155 said:
Congratulations on the new arrival Mike! One good thing with tall speakers is that the drivers will be out of reach of questing little fingers ..... at least for a while!

Dan
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Thanks Dan.

Im thinking of having wire mesh behind the grille cloth and maybe attatching the grille with some nice brass 'top hat' nuts (I might have some 'thumbwheel' type screws made up, or use brass allen heads, epos style). That way it will add a nice aesthetic feature and keep the drivers protected. Of course its not ideal for sound but it shouldnt effect it too much, and I can take them off when the nippers in bed.

Need to find out about crossovers now, its probably wise to have one designed from scratch, that leaves tweeter options open, and the possibility of asymetrical placement. Audio-conponents.co.uk have a measurement service which is well priced, and thye're not that far from me so I'll probably do that. Of course there might allready be some proven crossovers out there based on the Vifa midbass and a simmilar baffle profile. If anyone knows, please let me know.

Thanks for reading,

Mike
 
Mike,

Madisound offers a crossover-designing service, which is based on data they have collected from drivers they sell. Just tell them the dimensions of your cabs, and the drivers you intend to use, and they can put a design together for you. That would be cheaper and less frustrating than taking measurements separately from the designing.

James
 
James said:
Mike,

Madisound offers a crossover-designing service, which is based on data they have collected from drivers they sell. Just tell them the dimensions of your cabs, and the drivers you intend to use, and they can put a design together for you. That would be cheaper and less frustrating than taking measurements separately from the designing.

James
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Sound like a good soloution, thanks. I guess it would make sense to have a working crossover to start with, then I can make small tweaks to fine tune it if necessary.
 
I'd just try a 1.2 to 1.5 mH coil 18 g on the woofer see how it sound 18 to20 uf cap with a 6.8 ohm resister across the pos and neg of the woofer.

Steve
PS no computer was used to model this.

And I may even work my way down to a smaller coil .7mH on the woofer
 
hi fi fo fum said:
I'd just try a 1.2 to 1.5 mH coil 18 g on the woofer see how it sound 18 to20 uf cap with a 6.8 ohm resister across the pos and neg of the woofer.

Steve
PS no computer was used to model this.

And I may even work my way down to a smaller coil .7mH on the woofer
Click to expand...

Steve.

I think you meant tweeter, didn't you?

Dave.
 
No ...Coil in line with the pos of woofer /cap and resistor across pos and ground of the woofer... (impedance correction) but you might not need it with this type of enclosure
 
Drawings available now.

Cross section and individual panels available.

Please pm me if you interested, I will send to your email.

Mike


l_4df910c51e95b8f55b75f1902992bfea.jpg
 
Mike,

Textbook XO formulas don't work in the real work. Save yourself time and the cost of parts, and get the XO designed for you by Madisound.

James
 
I think I might have got lucky with a pair of blown FB1+ crossovers. Im not sure exactly the damage but I suspect its just blown resistors. If I cant repair then at least I can copy the circuit and build new ones. (the guys daughter had a party and overdid it a little with dads system)

I dont have them yet, the guy is waiting for replacements to arrive. Fingers crosse he dosent forget me!
 
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