Hi,
A friend just built himself a big DIY 10W/ch low distortion tube amp, and I've been tasked with designing a pair of small speakers for him. No floorstander, let alone horn. And as you can guess, the focus is on sensitivity. He wants to fill his modest room with the 10W/ch amp without turning up the volume much. And other than sensitivity, he's okay if the speakers are not the world's best. These will be in his "other room", his "main room" has horns and KlangFilm (?) amps.
I thought I'll build him a modest-sized 2-way, tune it for near-rear-wall placement, and let him fill his room with sound. I thought 93 dB/W/m ratings should be my cut-off for the drivers. And as always, it would be nice if the crossover design was not some Herculean task of cutting down monstrous cone-breakup nasties or other problems.
Well, I started by looking at the usual midbass suspects, and landed up examining FR drivers because of sensitivity issues. I'm now looking for any driver which will do the following:
I've come down to:
What do you think? Is my direction ok? If yes, then which of these drivers should I go for? Is the Audio Nirvana worth the extra dollars? I am nervous about "The Classic line has enhanced midrange detail compared to the Super Series" -- the FR curve shows the bump.
(You may be wondering why I'm talking about a 2-way, specially in the FR forum. This is because I am quite comfortable with crossovers (which FR devotees probably disapprove of) but I don't like the colouration in upper octaves which most FR drivers generate because of uneven SPL, so I prefer to mate with a dedicated tweeter. In this case, I'm using the G2Si because of its high sensitivity, and because I don't have to cross over very low (I hope!) Perhaps a decade ago, I've lived with the Jordan JX92S for a couple years, and I know its outstanding sound quality specially for voices, and somewhat harsh treble on-axis.)
Any thoughts greatly appreciated. Haven't played with any of these modern FR drivers ever.
A friend just built himself a big DIY 10W/ch low distortion tube amp, and I've been tasked with designing a pair of small speakers for him. No floorstander, let alone horn. And as you can guess, the focus is on sensitivity. He wants to fill his modest room with the 10W/ch amp without turning up the volume much. And other than sensitivity, he's okay if the speakers are not the world's best. These will be in his "other room", his "main room" has horns and KlangFilm (?) amps.
I thought I'll build him a modest-sized 2-way, tune it for near-rear-wall placement, and let him fill his room with sound. I thought 93 dB/W/m ratings should be my cut-off for the drivers. And as always, it would be nice if the crossover design was not some Herculean task of cutting down monstrous cone-breakup nasties or other problems.
Well, I started by looking at the usual midbass suspects, and landed up examining FR drivers because of sensitivity issues. I'm now looking for any driver which will do the following:
- Rated sensitivity: 94 dB/W/m or more
- At least 6.5" dia
- Fs lower than, say, 49 Hz
- T/S parameters roughly suitable for a bass reflex
- SPL curve in the passband should be reasonably flat, so that I don't get too much colouration at random places. Terms like "greater midrange detail" scare me -- I can only interpret this as a big bump in the SPL, giving an unrealistic amplified midrange.
- Will play from the bottom to about 2-2.5KHz, where a G2Si ribbon will take over.
- Price ideally within USD 100/driver
I've come down to:
- Betsy K
- Dayton Audio PS220-8
- Audio Nirvana Classic 8"
What do you think? Is my direction ok? If yes, then which of these drivers should I go for? Is the Audio Nirvana worth the extra dollars? I am nervous about "The Classic line has enhanced midrange detail compared to the Super Series" -- the FR curve shows the bump.
(You may be wondering why I'm talking about a 2-way, specially in the FR forum. This is because I am quite comfortable with crossovers (which FR devotees probably disapprove of) but I don't like the colouration in upper octaves which most FR drivers generate because of uneven SPL, so I prefer to mate with a dedicated tweeter. In this case, I'm using the G2Si because of its high sensitivity, and because I don't have to cross over very low (I hope!) Perhaps a decade ago, I've lived with the Jordan JX92S for a couple years, and I know its outstanding sound quality specially for voices, and somewhat harsh treble on-axis.)
Any thoughts greatly appreciated. Haven't played with any of these modern FR drivers ever.
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I agree that with an Fc of 2+ KHz, 8" seems too big -- it'll beam. But I don't seem to be able to get either the bass extension nor the sensitivity unless I go to 8". At 6.5", I'm getting the sensitivity but not the last two octaves. So, I was thinking of telling my friend to sit and listen on-axis, and just live with it. 
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I just discovered one more driver, so there's a fourth member in the race:
Good sensitivity: 93 dB. Low Fs: 44 Hz. T/S parameters good for a reasonable sized bass reflex box. The SPL curve is flat enough for crossover design to not be a real pain, I hope.
Maybe I'll just go with this one.
- The Fostex FF225WK 8" driver
Good sensitivity: 93 dB. Low Fs: 44 Hz. T/S parameters good for a reasonable sized bass reflex box. The SPL curve is flat enough for crossover design to not be a real pain, I hope.
Maybe I'll just go with this one.
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