help me design some speakers

[peterS]

my decisions rely heavily on Zaph audio's measurements
narrowed it down to this tweeter per the tweeter mishmash

http://www.madisound.com/cgi-bin/index.cgi?cart_id=1552150.346&pid=1325

now due to budget constraints i can either do a MTM with these vifas

http://www.madisound.com/cgi-bin/index.cgi?cart_id=1552150.346&pid=1429

or just a single scan speak revelator

http://www.madisound.com/cgi-bin/index.cgi?cart_id=1552150.346&pid=1165

i planed on a ported cabinet


the amp is a rotel 1080

opinions on which direction to take?

[cobbpa]

Chances are you will receive replies saying one of a few things:

a) Scrap the idea & build something in the Missions: Accomplished section. These designs are hard to beat. They're widely built so you get a lot of help, they've won awards, they're nearly unbeatable for the price...etc. etc.

b) If you want to really get involved, get some measuring equipment to measure in-baffle driver response. From there you or someone on here could cook up a crossover.

c) Use manufacturer's response graphs, this guide,, and go for your own crossover. Some very good designs have been made using this method. If you are lucky enough and someone is feeling gracious, they may do this for you.

In my case, I've gone with option A and the gracious helper route of C. Chances are, the Missions: Accomplished section choices will fulfill most anyone's needs. I only went the way I did with option C because I already had the drivers sitting around.

[Jonasz]

Try and contact Pete Schumacher over at the Madisound- or PE-forum. I know he has some experience with the Vifa tweeter and possibly also with the XG.

[ThomasW]

Might not be the best idea to match up a tweeter that basically dies at 2Khz

http://www.madisound.com/pdf/vifa/d26nc-55-06e.pdf

With a woofers that have their first breakup mode under 1Khz

http://www.madisound.com/pdf/scanspeak/18w_4531g00e.pdf

http://www.partsexpress.com/pdf/297-368s.pdf

[agrippa]

I agree with cobbpa. Go with a proven design. You may want to design the speakers around a purpose rather than a particular driver.

What are they for?
What kind of music do you like?
How do you like your music? A live feeling or a bit laid back?
And so forth.

[peterS]

Might not be the best idea to match up a tweeter that basically dies at 2Khz

http://www.madisound.com/pdf/vifa/d26nc-55-06e.pdf

With a woofers that have their first breakup mode under 1Khz

http://www.madisound.com/pdf/scanspeak/18w_4531g00e.pdf

http://www.partsexpress.com/pdf/297-368s.pdf

doh
thanks

probably going to go with this

http://www.zaphaudio.com/audio-speaker16.html

as the modula mtm's crossovers are too expensive for my taste

considering that i will have only a 15" sub does the ported version look worth while given its group delay or can i get by with sealed?
keeping in mind that progression towards an active set up or at least some sort of dsp is my goal

[JonMarsh]

Re the Vifa

The Vifa XG18H00 should be fairly easy to work with, but the distortion is about 10-15 dB higher than for the Dayton RS180 at playback levels around 90 dB up to 2 kHz. At least it has plenty of copper in the gap so the distortion doesn't rise too much with increasing frequency.




Vifa XG18H00 HD2

The HD3 is higher still.




RS180 HD2


Another alternative for midwoofer with very low distortion is the Peerless 830883.












The Vifa tweeter is a good choice for three ways with a midrange that can cross at 3 kHz or higher, but not for two ways. I'm preparing a center channel system design with it.

For a lower count crossover design than the Modula MTM, you might take a look at the Natalie P in either the 27TDFC or RS28a variant.

Out of Zaphauido's designs, I think the TMM with waveguide loaded Seas 27TDFC is a bit more "interesting".

[Jim Holtz]

For a lower count crossover design than the Modula MTM, you might take a look at the Natalie P in either the 27TDFC or RS28a variant.

Hi Jon,

I didn't realize there was a 27TDFC version of the Natalie P's. Is it posted?

Thanks!

Jim

[technimac]

Out of Zaphauido's designs, I think the TMM with waveguide loaded Seas 27TDFC is a bit more "interesting".

I can't remember which forum I read this on, but John Krutke did comment that his WG TMM's were currently being used as his "reference speakers".
That in itself is a testimony to the quality of their design and performance.

And, as Cobbpa noted, there are so many great, award-winning designs in the Mission Accomplished thread - something for almost every need. Jon's latest Non-BSC iteration of the Modula MT, Natalie P and Modula MTM speakers, doubles the choices with use and placement for those designs (never mind the variety of tweeters that can be used with them).

All are definitely worth a look!

Cheers, Bruce

[soho54]

I didn't realize there was a 27TDFC version of the Natalie P's. Is it posted?

It was suppose to be posted about the time he went missing. It probably hiding on some imperial server somewhere.

[technimac]

Hi Jon,
I didn't realize there was a 27TDFC version of the Natalie P's. Is it posted?
Thanks!
Jim

:yesnod: Ditto! And like Jim Holtz, I am interested in building a 27TBFC/G (H1212) version of the Natalie P's. I have that tweeter in my four Modula MT's and would like to be able to build tonal-matched Natalie P's, both with BSC and Non-BSC.

Evil Twin did talk about doing a 27TDFC Natalie P crossover here:

http://www.htguide.com/forum/showpost.php4?p=242778&postcount=198

...which was followed by a great positive response from many of those asking for one. ;x(

Jim responded then, by saying,
"Based on your previous comments, the crossover revision for the 27TDFC should also allow a 27TBFC/G (H1212) to be used without modification as well. That would be very cool and would make this superlative design even more cost effective to build. Excellent!"

:agree:

So I did look through the whole thread but couldn't find a 27TDFC version of the Natalie P...
...but then again, maybe I missed something. :huh:

I did notice that the posted Non-BSC version of the Natalie P is RS28-only as well.

Cheers, Bruce

[peterS]

jon i was not aware of the Vifa XG18's high distortion... zalph's site points to the contrary :huh:

im not comfortable using the rs28 due to the reported inconsistencies in there t/s
i liked their sound though and even more so the usher's they resemble

i would be very interested in the 27TDFC Natalie P too, but will look into the waveguide tmm in the meanwhile

i see one advantage is less lobbing... any disadvantages vs a mtm?

[morbo]

peterS, IIRC Zaph found the XG18 to have very low midrange distortion, but fairly high bass distortion. It seems best suited for a midrange or a midwoofer in a system that will be crossed over to a sub/bassbins at 100hz+ with steep slopes or 150hz+ with 'normal' reciever XOs.

I would certainly like to hear one used as a midrange sometime, here in Canada they are priced VERY attractively relative to other drivers.... If I had more funds, I would do a comparison of the XG18 vs. the CSS WR125 as a midrange in an actively crossed over 3-way... crossed over at something like 200hz 4th order to RS225s or RS315s. Both are very nice midrange drivers, that could shine if relieved of bass duty IMHO.