Hi-Vi M6a with Vifa XT25TG30.

[DrDyna]

Howdy folks!

I've got a pair of little 2 ways that I've made quite some time ago (recently remade the cabinets with leftover wood from a tqwt project), using Vifa XT25TG30-04 tweets and Hi-Vi M6a midbass units. Up until now, I haven't put much effort into the crossover, it's been a simple 6db at around 2500hz. I figured it would do for a little while until I had a chance to fuss with figuring out a better one.

I'd be curious to know what some opinions might be on a good crossover point and type. Any input and suggestions are appreciated!

[Einric]

You could try this crossover network.
The 2500hz looks ok for that tweeter. A 6" should still be able to produce upper vocals and instruments well.
There is a basic rule of thumb, Fs of Tweeter x3 = lowest recommended crossover point.
That being said I might be interested in trying a 2k or 2.2k X-over.

[DrDyna]

Originally Posted by Einric

You could try this crossover network.
The 2500hz looks ok for that tweeter. A 6" should still be able to produce upper vocals and instruments well.
There is a basic rule of thumb, Fs of Tweeter x3 = lowest recommended crossover point.
That being said I might be interested in trying a 2k or 2.2k X-over.

Thanks Einric, that looks a lot like what I was thinking about trying first.

Quick question though, does anyone have FRD or ZMA files for either of these drivers so they can be fussed with in Jeff Bagby's spreadsheet?

[jerome69]

frd/zma
David Ralph's Speaker Pages - Raw Measurements - Tweeters for the XT25.
For the M6A, not found on the internet, see this project : ZX Spectrum - undefinition

I have an idea, not easy to do, hope this could help

[DrDyna]

Originally Posted by jerome69

frd/zma
David Ralph's Speaker Pages - Raw Measurements - Tweeters for the XT25.
For the M6A, not found on the internet, see this project : ZX Spectrum - undefinition

I have an idea, not easy to do, hope this could help

Yeah, I couldn't find the M6a either. Perhaps I'll fire off an e-mail to HiVi and see if they've got one.

That looks like a decent crossover too, I might have to order some extra parts to try that one though, but not out of the question.

[jerome69]

I forgot a component to suppress the 9kHz peak, add a 0.15uF capacitor in parallel of L1 (2.2mH)
Just a word about the crossover, it is a LR2 @ 2.2kHz. For the XT25 nothing special. But the M6A have 2 peaks, one near 3kHz and an other at 9kHz.
Let us know, how it works

[DrDyna]

Originally Posted by jerome69

I forgot a component to suppress the 9kHz peak, add a 0.15uF capacitor in parallel of L1 (2.2mH)
Just a word about the crossover, it is a LR2 @ 2.2kHz. For the XT25 nothing special. But the M6A have 2 peaks, one near 3kHz and an other at 9kHz.
Let us know, how it works

Absolutely, I can hear those peaks too and was planning on asking if anyone had corrected them and what they used. This looks like a solid plan, thank you very much!

I'll see how much of this stuff I have in my parts bin already and what I've gotta grab from madisound. I'll let you know how it works out.

[wolf_teeth]

That 10 ohm resistor across the XT25 is a GOOD thing. You will damp the Fs enough where it will no longer be any issue at all. If the XT still buzzes on James Taylor, you'll know it.

WRT the M6a, I think the LCR may take care of the dual-peaks on its own if you reduce the resistor value, and/or decrease the cap size. You'll effectively notch out most everything above the xover point.

Looks like a decent sim.
Later,
Wolf

[chlorofille]

Originally Posted by DrDyna

Absolutely, I can hear those peaks too and was planning on asking if anyone had corrected them and what they used. This looks like a solid plan, thank you very much!

I'll see how much of this stuff I have in my parts bin already and what I've gotta grab from madisound. I'll let you know how it works out.

DrDyna, I use a similar crossover on my Vifa tweeter as well and found that it is a lot smoother and silkier with a 4.7uF series cap instead of a 10uF.

[jerome69]

Yes the XT25 will have a better sound, the crossover frequency will be 4kHz but the Hivi cannot goes so high