missing link in 2 way monitors...tweeters!

[tedmich]

I have been trying to make decent 2 way monitors for a while now, the challenge being getting an accurate tweeter which is nice sounding ( I prefer soft domes) while also getting a fairly flat response and a reasonable crossover frequency.
Getting a woofer which goes to an F3 of 60hz? No problem!
With reasonable sensitivity (>92db/w)? Harder!
Getting the same with a flat response through the all important mid/high frequencies (1k->5k) where most tweeters need to be crossed over? Much harder!

High end speaker companies are able to get good tweeters which can handle 1k-3k crossover in their 2-ways, as an example the UK made ProAc Response D28
http://www.proac-loudspeakers.com/da...28_Leaflet.pdf
and D38
http://www.proac-loudspeakers.com/da...esponseD38.pdf

they cost between $6-10K per pair, and their tweeter is now available as a closeout at Partsexpress for <$20!

279-173 Vifa DX25SC17-04 1" Fabric Dome Neodymium Tweeter 4 Ohm

they have 2 other Vifa/ProAc models
279-177 Vifa BC25SG19-04 1" Textile Dome Shielded Tweeter 4 Ohm
279-175 Vifa BC25TG19-04 1" Textile Dome Tweeter 4 Ohm

I'll report back when mine are done!

[Enzo]

I think you will find in general that guitar speakers are a lot more efficient than hifi speakers, which studio speakers would be.

Parts Express has a ton of speakers to chose from, as well as crossovers and such. I have not dealt with them in years, but Madisound used to carry a selection of hifi drivers.

And they are wholesale only, but Martin Sound Products has some pretty good prices ona number of things you might want.

[tedmich]

thnx Enzo!

Vifa DX25SC17-04 are GONZO

2 other ProAc tweeters still available at PE

[Steve Conner]

Do you mean monitors as in stage monitors- "wedges"- or as in studio monitors?

I assume you meant studio monitors. Anyway, the secret of modern 2-way monitors is that the woofer isn't flat right through the crossover region. The designer uses the woofer's own rolloff as part of the crossover network.

Nowadays they use computer optimization to do this, so it's thanks to computers that 3-way speakers have become almost extinct. You measure the driver frequency response and load it into the computer, and it calculates the crossover network for you so that crossover plus driver gives the response you wanted.

Sometimes they play the same trick with the tweeter, and that's how come you can see even quite high-end speakers whose crossover consists of just a capacitor for the tweeter. The crossover response is still second- or third-order, but only one of the poles is actually in the crossover network! As far as I know this only works with tweeters that have ferrofluid in them, as well as the desired cooling effect it damps the resonance and allows you to operate right through it.

Oh and there's a law of woofers just like the "Better, faster, cheaper- choose two" thing, except it goes "Lower, louder, smaller". You can have any two of: low f3, high efficiency (= high SPL before burning out) and small physical size. They're no different to their canine namesakes in this respect: a Shih-Tzu is never going to snarl like a Rottweiler.

Usually in stereo and studio monitors, the sensitivity is compromised to get deep bass in a small cabinet. For instance, I have a pair of Dynaudio BM5s that are rated 87dB, and that's on the 2.83V standard. You just make up for it by pounding them with a big amp. My tube hi-fi struggles to drive them and sounds awful, and hooking them up to a 150Wpc solid-state amp makes a huge difference. I bought them 2nd hand years ago, and if they weren't so tube-unfriendly, they'd be my favourite speakers ever.

If you want to make your own stereo speakers, Vance Dickason's Loudspeaker Design Cookbook comes highly recommended.

[Enzo]

Since he is talking soft dome tweets, I tends to think he is into studiio monitors.

[Steve Conner]

Well, I once saw a friend make a set of wedge monitors with dome tweeters. I thought he was crazy.

[Enzo]

Oh I don;t rule anything out in this world.

[tedmich]

yes anything is possible enzo!

Congrats on 10k!

3 ways aren't extinct, check these PMC BB5-A studio monitors using the Volt radial drivers:



only $79k! I hope that's for a pair, right?