Scott Simonian
Screenwriter
- Joined
- Jun 20, 2001
- Messages
- 1,281
Now we're talkin'.
They'll be at CES, too! VSAC is before CES, so it will be the first public showingI'll be at both!
So cool, I can see it now....Boeing, Starbucks, Adire...
well, Starbucks and Adire anyway.
(Seattle humor)
Hey, I'm all for complicated designs, but I'd like the option to use 6dB/oct slopes with tweeters as well.Your choice. First order designs almost always have higher levels of distortion and/or lower SPL capability than those using steeper slopes. About the only way around it with first orders is to use lots of drivers and lots of crossovers, like a Dunlavy -- not exactly a "simple" system.
First off what is dopple distortion and why will it increase if the tweeter uses a little more Xmax? Higher Xmax in subs and midwoofers has never been a problem why would it be a problem in tweeters?Doppler distortion is what you hear when an emergency vehicle, sirens blaring, whizzes past you--the pitch of the siren seems to drop down a few notes as it passes. Likewise, if a tweeter dome is cycling through large midrange excursions while simultaneously whistling a high note, that note will sound warbly--higher as the dome swings forward, and lower as the dome swings back--modulated by the lower frequency. Above a certain modulation frequency, your ear may not be able to pick out the warble, but it will still tell you somethings wrong--distortion.
But there is hope if you think outside the box. A properly designed horn-loaded diaphragm has to swing much less excursion for a given freq./SPL, thereby sidestepping doppler distortion. So I would suggest thinking in that direction. Hey, I bet you could still stir XBL^2 into the mix!
Bill
Your choice. First order designs almost always have higher levels of distortion and/or lower SPL capability than those using steeper slopes. About the only way around it with first orders is to use lots of drivers and lots of crossovers, like a Dunlavy -- not exactly a "simple" system.I probably wasn't clear with my wording. I didn't intend to imply that 6dB/oct systems were in any way "simple." And of course the doppler distortion is greater in general with (a) a simpler system (2-way vs. 3/4+ way) and (b) lower order XO designs. You pointed out that 6dB/oct systems are typically SPL limited... and you're right. That's why I said it would be nice to have the option of higher Xmax drivers, thus making possible 6dB/oct systems capable of higher SPL without a 12-way design. It's always a trade-off... doppler for 6dB/oct in this case. Still nice to have more options.
How does a full range driver designed to produce frequency ranges from 100hz-15khz get away from doppler distortion? They must have extremly high distortion ratings all things considered.Yup. I like full-rangers a lot for certain things, but they do suffer from doppler distortion. That's probably why they do simple music really well (human voice, for example), but usually slip and fall on complex orchestral music, at least in my experience.
And hey guys, why the sadness at the limitations of dome tweets? Even though you may have heard some cheap ones that sounded really rotten, there's nothing at all wrong with a good treble horn. You can have dynamics, controlled directivity, extension, and low distortion served up with high-sensitivity gravy.
According to Dan XBL^2 technology can be applied to all types of drivers EXCEPT planars.Yup. All you need is twin magnetic gaps with a coil straddling them.