What kind of competition? DB drag?
I have really great sound from my OB's. Deep bass also. Built a pair of Lampizator P17. Skipped the greencones and used something quite different. Yamaha 12" organ speakers for mids and Phillips silk domes. 15" bass drivers comes from CW V15F if I remember correct.
All passive x over. No biamping.
I have really great sound from my OB's. Deep bass also. Built a pair of Lampizator P17. Skipped the greencones and used something quite different. Yamaha 12" organ speakers for mids and Phillips silk domes. 15" bass drivers comes from CW V15F if I remember correct.
All passive x over. No biamping.
-it's a "sliding-scale", the lower the better. Probably .5 as a starting point.
Drivers typically used in horns have particularly low Qe, often close to .2. ("..oh my horn is SOOOO dynamic!" ..um, it's not the horn providing that subjective effect.)
Of course it's a problem as far as roll-off is concerned: you net a decreasing spl result the lower in freq. as Qe drops.
BTW, to preserve "punch" make sure your low-pass/eq.-comp. large value steel core inductor has as low a resistance as possible, and you are always best-off lower in freq. if you linearize/flatten the impedance at Fs.
(..while not spec.ing for "punch", I'll typically use a driver higher eff. pro driver with a Qe around .6-.7 and then an inductor with a high resistance to get a decent freq. response for the upper-bass.)
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Thank-you, for the response. This is really good news for me ! The driver I am considering using for a mid-bass application has a Qes of 0.52 No worries on the type of inductor, as I don't use any passive crossover parts. Now as far as the impedance peak at fc (a sealed system) are you saying to still use a zobel to flatten the impedance peak ? If so, that's an idea I would have never thought about, so thanks for that as well.
Again, though: less "punch" effect for something near .5, more "punch" effect for something near .25.
Not a Zobel, a series RLC to flatten the peak at Fs (..and it's still Fs considering that it's open-baffle):
The Crossover Design Cookbook Chapter 3: Speaker Motors and Crossovers
Note: you would NOT use this if you had the driver connected to a high-output impedance amplifier, and in fact a high-output impedance amplifier (aka: Current Amplifier) would offer benefits over a traditional low-output impedance amp (..lower distortion and a natural "lift" in freq. response relative to the impedance.) Still, almost no one does this.
Not a Zobel, a series RLC to flatten the peak at Fs (..and it's still Fs considering that it's open-baffle):
The Crossover Design Cookbook Chapter 3: Speaker Motors and Crossovers
Note: you would NOT use this if you had the driver connected to a high-output impedance amplifier, and in fact a high-output impedance amplifier (aka: Current Amplifier) would offer benefits over a traditional low-output impedance amp (..lower distortion and a natural "lift" in freq. response relative to the impedance.) Still, almost no one does this.