Using full range with natural rolloff to avoid warble tone?

Destroyer OS

Member
2005-11-14 11:09 pm
PNW
If you use a fullrange, and you want to listen to complicated rock, etc...

How low must you rolloff the lower frequencies in order to avoid compictaions from warble tone? The Alpair 5 looks nice because ported it naturally falls pretty steep at 100hz... I'd probably use 4X of them to achieve efficiency for crest factor, and even consider a tweeter. What I'd like to avoid is a capacitor inline with them. Tweeter probably wouldn't cross until well after 3khz.

This is just an idea I've been playing with, but I'm new to speaker design.
 

Destroyer OS

Member
2005-11-14 11:09 pm
PNW
I want to avoid combing... that's why I thought a tweeter might be the ticket.

The idea is to keep the 300-3000hz sweet spot.

Bob Brines talks about warble tone problem on his website.

The problem with the driver is it's just about useless by itself. At the efficiency it has, and it can only take 15w, it's nearly impossible to get good crest factor. And it won't do bass frequencies. Forgoing the tweeter is fine, I just was worried the distance between drivers would be too great for the much higher frequencies and it would do combing (and hopefully be close enough to avoid it for the range they play).
 
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zman01

Member
Paid Member
2011-02-04 11:35 am
Dhaka
Destroyer OS,

Maybe it will be better to go for a design that will meet your objectives of building the speaker. If a particular wide-band driver or wide-band units as a category do not satisfy your goals (like testing your amplifier), trying to fit them into certain usage models will create additional complexities.
 

Destroyer OS

Member
2005-11-14 11:09 pm
PNW
My objective is 3-3 with no series capacitor, crest factor above 100db at listening position, and very very good quality of sound.....

The problem with that is I don't like the sound of say Fostex FE126en so much... There's not a lot of fullrange driver units that can achieve an acceptable crest factor. Very few, mostly Fostex that aren't really what I want.

4x 5.2's seems pretty darn ideal. 60w power handling, crest factor above 100db at listening position, high efficiency for easy amplifier pairing. They easily can do 3-3. And the quality may be outstanding.

What I don't know is how high the frequency must be to avoid warble, or how low it must be to eliminate significant comb filter. (I know some guys want a truncated version of the MA's face so they can get cones closer)

If warble isn't a concern below 100hz, I'm set. Then I just need to know how bad comb filter is running no tweeter, and how bad it is at just above 3khz so I can use a tweeter.
 
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Alpairs are quite power limited and don't like to get hit with high power peaks. Maybe you can look into pro audio single mid/full range that can generate higher SPL and handle power with a single driver. Avoids warble or comb filter effects of multiple drivers.

Check out PRV 5MR450-NDY. 95dB sensitive and handles 225w with 275Hz high pass filter. Works up to 15kHz so low passing at 4kHz is no problem to cross over to a tweeter. It's a very low distortion nice sounding driver.

I have not used it but Galaxy 5in full range with Nd motor also looks like it is worth a try.

Faital Pro 3FE22 or 4FE32 also high sensitivity and smooth sound.
 
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You're slowly selling me on the PVR. I am a little worried it won't be as good as the very advanced MA or AT.

I don't personally listen loud, but I think dynamics matter.

The AT doesn't roll off well until maybe 150hz. It does however have a striking good acceleration factor, and a vented dust cap.
 
The PRV 5MR450NDY is absolutely incapable of bass due to its stiff suspension so intermodulation distortion would be a rare thing as the cone just can't move appreciable. The AT on the other hand looks like a softer more compliant suspension (55Hz fs) and 6mm of motion so if not high passed it can move. In a way, the PRV is mechanically high passed as the fs is 175Hz and the cone barely moves as it is mounted to a spider and surround that could support a small baby.
 
That's fairly appealing really. My plan would be to control the box very well to try and minimize reflections in box so that it could be a very refined sound.

The Xmas, sensitivity, etc, makes it ideal for fighting warble tone. I could pass it rather high too. I just hope it's a stiff enough cone and fast enough for crossing to a tweeter that's not soft sort. (No RAAL)

Also I may have to time align it if I crossover high... Which should work better with a tighter driver that's not flopping around.