Thor/Viva/XO question

[w.gruenewald]

I've completed the Thor cabinets as per plans provided by Seas. However, I plan on using the following drivers: VifaXT25TG30-04 tweeter, and PL18WO-09-08 mid/woofers (2), due to cost. I've offset the tweeter,so as to "mirror image" this design. I am in need of a cross-over design for this project, as well as opinions from those who have build this design, and from those who have experience with these drivers. Anything is appreciated.

 

[FrankDIY]

Well, you have to start from scratch. There a lot of steps to design a good crossover. In short, you have to measure the drivers impedence with a software, determine a good impedance compensation network and remeasure the system. With the new impedence curve, you can determine the impedence at the crossover point and then design the crossover from this number. You will probably need an L-Pad for the tweeter and maybe a notch filter if your crossover point is too low. Nobody can pretend design a crossover for you without having the real number for your drivers.

search on google and here for crossover design and you will find usefull reading.


Good luck!

 

[bacworth]

I don't know if I would be using those speakers in those cabinets, I thought they were designed for the Excel range. Anyways, I have used the Vifa driver you talking about, don't know exactly the specs on those seas drivers but i would cross them @ 3000hz - 4000hz 18db. It is a tought call without the specs as Francois suggests.

Brent

 

[BrianGT]

I am not so sure that those driver will work very well in that enclosure. The excel/millennium seas drivers were crossover at 2.5khz. The article on the design is at:
http://brian.prohosting.com/nancy/thor.pdf

The driver parameters are different, so I don't think that the cabinet would be optimal. I would save your money and buy the excel drivers. I love the sound of the Thor TL speakers.

Here are pictures of mine:
http://brian.darg.net/thor

--
Brian

 

[BrianGT]

Here are the specs from the respective websites:

--
Brian

 

[BrianGT]

tweeters:

--
Brian

 

[jgwinner]

I agree with everyone. I haven't heard my Thor's yet (still working on the cabinet) but I agree, I think with a different driver you'll have to rethink everything.

The Transmission line length is based on the Fs, and the two drivers have a different Fs.

When I built my sub I finally realized there were 'no magic numbers'. If I made my sealed enclosure a few cubic inches too big or small, it only moved the sound toward or away more Q.

However, with a TLine you are working on a 1/4 wavelength, and that wavelength is different.

Or at least, I think. I think you should sit down with some modeling spreadsheets (i.e. Martin's mathcad models) and fiddle with it.

A cheaper TL like Thor is a very worthwhile project, however, I think it's an excellent idea.

Also, Martin and Dave weren't convinced that the Thors were an optimal design, so there is some additional work on the design that could be done anyway. I'm 1/2 way thorugh this, but I quit armchair quarter backing and just BUILT the things as is to get something going SO it wouldn't hurt if there was more work done on the basic Thor design.