Gary Dahl, can you do some off axis responses out to 90 degrees? I've wanted to see that on those drivers for a long time.
That looks extremely impressive not only for a 15 inch speaker but for any speaker on axis. My own experience with these larger drivers has been that the smoother the on axis, the smoother the off axis. I don't know if that's necessarily the case however.
This:
went to this after a few rounds of cone damping:
Anyway, I am exceedingly interested in seeing what this speaker can do off axis.
Dan
That looks extremely impressive not only for a 15 inch speaker but for any speaker on axis. My own experience with these larger drivers has been that the smoother the on axis, the smoother the off axis. I don't know if that's necessarily the case however.
This:
went to this after a few rounds of cone damping:
Anyway, I am exceedingly interested in seeing what this speaker can do off axis.
Dan
Hello Lynn,
Some thoughts about high sensitivity and things involved therein.
One can think how high sensitivity is usually obtained: using big horns, for example. They have the additional property for having very high directivity, and thus having less room reflections. Lack of listening room reflections leads to more perceived "detail".
However the level independent 'tonal character' is something unexplainable taking into account human level dependent loudness perception. Well, loudness is integrated in the brain and if there is less reflections integration does not yield and mostly direct sound defines the loudness. Still it's unknown how it could be level independent ??
Can it be simply the fact that at low levels there is nothing small detail left for the ear to hear? The ear has a minimum sensitivity level and if listening at low level most of the small amplitude signals are under the threshold.
- Elias
Some thoughts about high sensitivity and things involved therein.
One can think how high sensitivity is usually obtained: using big horns, for example. They have the additional property for having very high directivity, and thus having less room reflections. Lack of listening room reflections leads to more perceived "detail".
However the level independent 'tonal character' is something unexplainable taking into account human level dependent loudness perception. Well, loudness is integrated in the brain and if there is less reflections integration does not yield and mostly direct sound defines the loudness. Still it's unknown how it could be level independent ??
Can it be simply the fact that at low levels there is nothing small detail left for the ear to hear? The ear has a minimum sensitivity level and if listening at low level most of the small amplitude signals are under the threshold.
- Elias
I agree with Badman. Intelligibility of song lyrics is a pretty simple criteria: either they're easy to understand or not. Some speakers do well at low levels, and others do not.
Electrostats and horns do well at intelligibility at low levels, and other types vary. I don't want to step into the swamp of capacitor audibility, but I've found that swapping capacitors can make more of a difference here than might be expected - to that extent that any capacitor has a "sound", it's in audibility and clarity of low-level sounds.
The only reason I even bring this up was that I found that swapping caps in the Ariel project - Brand Z for Brand A - was that I sometimes had to the adjust the HF crossover by 1/2 dB to retain subjective flatness, as well as encountering the difference in low-level detail. I'd be the first to agree that capacitor audibility is much subtler than chasing out driver and cabinet coloration, and is more evident after a speaker is corrected to flat response than before.
In a similar way, efficiency of the driver plays a role in capacitor audibility. There are plenty of drivers and complete loudspeaker systems where swapping any cap, including the notorious "non-polarized" electrolytic, is essentially inaudible. There are other - typically high-efficiency - drivers where cap swaps are fairly noticeable on direct A/B/A changeover.
What's going to help on the overall parts count in the crossover is the TD15M and AH425 & large-format compression driver have well-behaved responses in the 680 to 850 Hz crossover region. No need for notch filters, no need for shelf equalization, and the system is designed so the AH425 is freestanding and easily slid back and forth for phase matching in the crossover region. The first target filter will be 2nd-order lowpass for the woofer, and 3rd-order highpass for the HF horn.
What simplifies the system design is that large-format studio monitors are a well-trodden path going back to the Lansing Iconic - and the crossover frequency, dictated by the bandwidth of the horn and the performance of the 15" paper-cone woofer, is similar. Should work very well sitting on the left and right sides of Gary's 120" projection screen. Plenty of tradition there - large-format studio monitors are pretty close to what were used in the private screening rooms of Hollywood producers, directors and movie stars. Use a reasonably powerful PP tube amp, and you have a historically correct playback system for movies made from the Thirties through the mid-Seventies.
Electrostats and horns do well at intelligibility at low levels, and other types vary. I don't want to step into the swamp of capacitor audibility, but I've found that swapping capacitors can make more of a difference here than might be expected - to that extent that any capacitor has a "sound", it's in audibility and clarity of low-level sounds.
The only reason I even bring this up was that I found that swapping caps in the Ariel project - Brand Z for Brand A - was that I sometimes had to the adjust the HF crossover by 1/2 dB to retain subjective flatness, as well as encountering the difference in low-level detail. I'd be the first to agree that capacitor audibility is much subtler than chasing out driver and cabinet coloration, and is more evident after a speaker is corrected to flat response than before.
In a similar way, efficiency of the driver plays a role in capacitor audibility. There are plenty of drivers and complete loudspeaker systems where swapping any cap, including the notorious "non-polarized" electrolytic, is essentially inaudible. There are other - typically high-efficiency - drivers where cap swaps are fairly noticeable on direct A/B/A changeover.
What's going to help on the overall parts count in the crossover is the TD15M and AH425 & large-format compression driver have well-behaved responses in the 680 to 850 Hz crossover region. No need for notch filters, no need for shelf equalization, and the system is designed so the AH425 is freestanding and easily slid back and forth for phase matching in the crossover region. The first target filter will be 2nd-order lowpass for the woofer, and 3rd-order highpass for the HF horn.
What simplifies the system design is that large-format studio monitors are a well-trodden path going back to the Lansing Iconic - and the crossover frequency, dictated by the bandwidth of the horn and the performance of the 15" paper-cone woofer, is similar. Should work very well sitting on the left and right sides of Gary's 120" projection screen. Plenty of tradition there - large-format studio monitors are pretty close to what were used in the private screening rooms of Hollywood producers, directors and movie stars. Use a reasonably powerful PP tube amp, and you have a historically correct playback system for movies made from the Thirties through the mid-Seventies.
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I agree. Maybe it is possible that caps in the crossover are the bad actors here, along with subtle aspects of driver construction.
For example, (correctly restored) vintage table radios sound remarkably good at speech reproduction at moderate levels, while a modern multiway low-efficiency high-end loudspeaker can sound muffled, dull, and unintelligible at the same levels. Culprits? Class AB transistor amps, arcane differences in glues, voice-coil formers, spiders, surrounds, low-efficiency drivers, and complex crossovers that use certain varieties of crossover caps. Mostly guesswork, to be honest, but that's been my experience.
You shouldn't have to turn a hifi system up to U-571 depth charge levels to get the speakers to "turn on". That's ridiculous. If the system is muffled at low levels, something is wrong.
For example, (correctly restored) vintage table radios sound remarkably good at speech reproduction at moderate levels, while a modern multiway low-efficiency high-end loudspeaker can sound muffled, dull, and unintelligible at the same levels. Culprits? Class AB transistor amps, arcane differences in glues, voice-coil formers, spiders, surrounds, low-efficiency drivers, and complex crossovers that use certain varieties of crossover caps. Mostly guesswork, to be honest, but that's been my experience.
You shouldn't have to turn a hifi system up to U-571 depth charge levels to get the speakers to "turn on". That's ridiculous. If the system is muffled at low levels, something is wrong.
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But not nearly as well as a vintage vacuum-tube radio. Compare them sometime. You'll be surprised just how much worse the modern product sounds. I'd put a Zenith AM-FM radio from the Fifties against any of the modern table radios.
But then again, when you compare prices in inflation-corrected dollars, those table radios were very expensive compared to any modern equivalents. Not that table radios had any pretensions to hifi, even back in the day - but if table radios were not cheap, enthusiast hifi was truly expensive at a time when a nice house here in the USA could be bought for $10,000. Think about it: what would seem like a basic system comprised of a Garrard record-changer, Shure cartridge, Dynaco preamp, Dynaco power amp, and AR or KLH speakers would be about 1/20th the price of a house. A system centered around Marantz or McIntosh would be 1/5 to 1/10th the price of a house.
Not cheap at all. Makes you realize that exotic home-theater or all-triode audiophile systems have essentially stayed constant in price.
But then again, when you compare prices in inflation-corrected dollars, those table radios were very expensive compared to any modern equivalents. Not that table radios had any pretensions to hifi, even back in the day - but if table radios were not cheap, enthusiast hifi was truly expensive at a time when a nice house here in the USA could be bought for $10,000. Think about it: what would seem like a basic system comprised of a Garrard record-changer, Shure cartridge, Dynaco preamp, Dynaco power amp, and AR or KLH speakers would be about 1/20th the price of a house. A system centered around Marantz or McIntosh would be 1/5 to 1/10th the price of a house.
Not cheap at all. Makes you realize that exotic home-theater or all-triode audiophile systems have essentially stayed constant in price.
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Of course, there are SE valve amps in there too. I have had the experience of several salvaged and restored Saba. I mentioned Tivoli in contrast to the modern favorite speakers since its available and most have listened to one. Still a small FR in a small box.
