2.5 way system using Vifa drivers.

Just an idea at the moment, but I am thinking of attempting to build, a 2.5 way system using some Vifa tweeters I already have (D25AG-35-06) and two 6.5" mid woofers.

Basically I would like it to be no larger than 25W x 35D x 100H (external size) so they will be floor standing speakers, with the tweeter on top, both woofers mounted as high as possible below it and a port down near the bottom.
Looking at those dimensions the max internal volume would be around 55L.

After doing various sums and calculations, I was thinking either of these woofers would work well??
http://www.datasheets.pl/SPEAKERS/VIFA/M18WO0908.pdf
http://www.tymphany.com/files/resources/dvifa/PL18WO09-08.pdf

Even though these are discontinued, I can get hold of either of these drivers quite easily so that's not an issue.

Is there any particular woofer out of these that stands out more than the other in this sort of design?

I'm guessing that both of these are decent quality woofers??
Any similar diy designs out there?

Crossover point will likely be around 2.5kHz - 3kH I'm guessing.

I've been reading up on 2.5 way past designs so I have a fair idea about how they work.

This is just a general question at this stage, no need to get too serious yet, ;) I'm just trying to get some ideas on how to tackle this. (if at all)

I'm not after the greatest speakers ever, but I wan't something with good bass response and overall good performance.

Any help appreciated :)
 
If it had to be a choice of those woofers, I would go with the PL18's. I have been using that in my reference speaker since 2006 and I really like it. Not terribly difficult to crossover either.
I would ditch the viva aluminium tweeter and go for the DX25 or XT25 if you wanted to stick to vifa.
option 1
look up EROS SPEAKER on Google or parts express diy speaker showcase and I still think it is there.

option 2
is to copy the Nebula and then run the second vifa off a 4.7mh to 2.7mh inductor.

option 3

try Troels Vifa design with series crossover and again crossover .5 woofer off a large inductor.


Vifa PL18WO-


good luck and you have come to the right place.


cheers

Jonathan.
 
If it had to be a choice of those woofers, I would go with the PL18's. I have been using that in my reference speaker since 2006 and I really like it. Not terribly difficult to crossover either.
I would ditch the viva aluminium tweeter and go for the DX25 or XT25 if you wanted to stick to vifa.
option 1
look up EROS SPEAKER on Google or parts express diy speaker showcase and I still think it is there.

option 2
is to copy the Nebula and then run the second vifa off a 4.7mh to 2.7mh inductor.also parts express showcase.

option 3

try Troels Vifa design with series crossover and again crossover .5 woofer off a large inductor.


Vifa PL18WO-


good luck and you have come to the right place.


cheers

Jonathan.
 
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Ok, I figured they are the better of the two, that could be a goer then. Although the M18 is a little easier for me to get hold of.

Thanks for the suggestions so far.

Tonally, do they both sound similar in the midrange given they are both paper based cone drivers?

Compared for example to the P17WJ-00-08 (polycone) which I have in my centre and rear speakers would either of these woofers sound very different?

Anyone done any comparasions?



Thanks :)
 
I have used both the P17 and P18 and have very similar mid range ability but the P17 is just a little bit bass shy in comparison.

If you can get the M18 then as per their FS they look identical. the P17 Has a smoother flatter response and would be easier to do a simple crossover. no nasty break up nodes and basically flat all the way.

Why not use the p17 as your top woofer handling the mid range and use the M18 as your .5 woofer and take that to about 250hz/300hz. that would be far easier to filter than the rising response of both M18 and PL18.

cheers
Jonathan
 
Interesting thought, I guess that's possible.
I would have thought however, the 2 woofers would need to be identical in a 2.5 way??

Other than this idea I was now thinking maybe a 3 way might be better idea.
As my centre channel already has a Peerless 830870 4" midrange, http://www.essentialaudio.com.au/pdf/peerless/Peerless_830870.pdf maybe that will work with two M18's. (or PL18's)

Decisions decisions. :)
 
Well, its been a while.

I ended up building these only last month, used very similar dimensions to what was in my first post.

I'm using four M18 woofers (the PL's were too costly in the end) and two D25AG tweeters. Yes, I considered the Vifa XT's but I really do like the D25's sound and I already had a spare pair of them anyway.
BTW: all the drivers are the original Danish made ones. :)

They sound very good to my ears, but the crossover is still unfinished.
After a lot of playing around, its currently:

3mH LPF on lower woofer

0.82mH LPF on upper woofer

5.6uF and 0.47mH 12db/oct HPF on tweeter, then an L-pad (1ohm in series and 12ohm in parallel)

So far so good.
 
Here's some pics, I didn't take that many :)

All panels are 32mm (1.25") MDF.

Still unfinished as you can see.
 

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