Vifa & Scanspeak drivers in a TL

[Dalinebuilder]

In the past 55 years I have built all my speakers, including Atkinson state of the art and Webbs daline (=superb).

I had bought P13WH, 9500, D27TG and crossover parts to build 2 Ariels (for music) and 3 Esquires for HT. I am now limited by health (routing is a bit dangerous now) and space (her inside thinks the Ariels are too tall!) to do this.

I am designing smaller TL alternatives.

Assuming 60Hz for Fs on the P13 and an MTM, do I double the Sd area on the P13 and keep 60Hz for the calculations? For the crossover, as I am using a 65w amp at 8 ohms, I think I can still use the Ariel XO but is the low pass "impedance correction network" to allow for a tube amp and so can I ignore it, and should I increase the resistor wattages to allow for the extra power?

The HT speakers will now be smaller TLs keeping the Esquire XO, but with a yet to be decided centre.

All help and info gratefully received. Tks in antic.

Pat S

[martinbls]

Where did you buy those Vifa 13WH, since they're no longer in production?

Martin

[simon dart]

You can buy brand new P13's from Falcon Acoustics in the UK. Scanspeak made from original tooling.

[martinbls]

Really! Amazing...
But, indeed quite expensive units! That's a bit disappointing. It would be much cheaper to buy some P17WH's from madisound.

Oddly, it seems that no european supllier sells those classic line Vifa drivers, even though these are made in Denmark!

Pat, do you really think the Ariels are too tall? With some nicely rounded edges and a decent veneer I think these are nice looking speakers. And perhaps, if you listen to them for a couple of days you'll forget about the size...

[chrisb]

For one of my early DIY speaker projects over 10yrs ago I'd considered the Ariel, but dumbed it down a little bit (cost/complexity of the XO mainly) , and ended up with the following ( TM only)


Transmission Line Speakers



"so let's not fix it"? - well as I said, it was an early project, and gently retired after about 5 yrs.

[GM]

Originally Posted by Dalinebuilder

In the past 55 years I have built all my speakers.............

I am now limited by health (routing is a bit dangerous now) and space (her inside thinks the Ariels are too tall!) to do this.

Assuming 60Hz for Fs on the P13 and an MTM, do I double the Sd area on the P13 and keep 60Hz for the calculations?

For the crossover.............

My kind of DIYer!

Know the feeling.......... though none of the women in my life ever voiced any 'issues' WRT any of my large speaker systems. They were too busy enjoying their music emanating from them too much to care about how they impacted room decor.

Don't know how you design TLs, but doubling Sd isn't a valid way to do it unless you already have a successful single driver design based on it. Normally, one doubles Vas, but typically folks design a single driver alignment using T/S, then double its net box volume [Vb] and if vented, double the number of vents, though of course with a TL one just doubles the cross sectional area [CSA] of the entire TL's length.

Dunno, ask Lynn, he posts here: http://www.diyaudio.com/forums/members/lynn-olson.html

GM

[TerryO]

I always felt Lynn Olson's Me2 speaker was better sounding, it can be stand mounted and uses the same drivers (and crossover, IIRC). You could augment them with a sub, if you'd like more bass.

Best Regards,
TerryO

[simon dart]

Taking nothing away from Lynn's superb design skills, as Scottmoose pointed out; the mathematical modelling of TL's has come a long way since Lynn designed the Ariels.

See...

Ariel construction

...onwards. Wish I saw this before spending 5 months building mine! :-D

[Dalinebuilder]

Many thanks for all your replies and info - greatly appreciated.

The Vifa and Scanspeak were bought in from abroad Spaion and UISA).

We have recently moved house and downsized so a pair of Webbs were a little large for the lounge anyway - even if the 20Hz, smoothness and clarity (I could go on!) was nice!!

Thanks Chris, has seen the MT on the web.

I understood that once one had the Fs, Sd that was all one needed to find the line length etc. A 2-M would still have a Fs of one if the same Fs. Two would not lower the resonance frequency and give a lower bass? So if one had an Fs of 60Hz you could allow for 2 by doubling the cone size.

This gave me a line length of about 63 inches, but the 2-M version was a little deeper. (Compare PMCs Fb1 with MT and their OB1 with WMT and is only slightly larger than FB1).

I will investigate scotchmoose version soon an will post again.

Did anyone have an answer for the XO wattage problem? THe XO is designed for, say, a 6 watt tube amp not my 65 watt tranny.

Thanks to all again

Pat S

[Scottmoose]

The driver's piston area is essentially irrelevant to the line dimensions. Pipe frequency is a function of length & taper; the line cross section (or total pipe volume if you prefer) is no different in general principle to any other vented box, being dominated by Vas and Qt.

Re the Ariel, I have revised my views (and learned) considerably in the 5 years since the thread linked to above (which I'd clean forgotten about); enough that I would say for the most part, ignore it, and my often inaccurate pontificating. An excess of zeal is no excuse, & I tender my sincere apologies.