David Karmeli's Natural Sound in Utah

[Audiophile Bill]

Yes, my limited understanding of excursion is out and back. But I thought there was terminology about how quickly a speaker returns to its default state. Brad or Bill may know.

Hi,

The ability of a cone to return to its starting position is basically a function of the weight of the cone itself (hence why say the vintage doped paper cones are so light versus a cone made of carbon or plastic), the force of the motor (that is the magnetic force induced by the motor on the cone) - again the vintage drivers use very powerful alnico or field coil magnets typically, the x max which is the distance that the cone is able to move in this “system” (usually very low in vintage designs) and the stiffness of the suspension of the cone - the vintage drivers often use quite stiff suspension made from impregnated / doped fabric or even leather versus a modern floppier rubber.

Best.

 

[tima]

Did you find it more coherent than what you are used to? 2-ways can be more coherent, but here there is one driver with horn loading and other with cone loading.

To tell the truth, I had no sense of coherence or incoherence. That means nothing in the sound at David's caused me to take notice of any disjointedness between the lows, mids, and highs. I take that as coherent. I conjecture that part of the ease I described was from my mind not having to work subconsciously to compensate for timing irregularites.

Wrt to the Alexias, I can tell you the Series 2 definitely sounds more coherent than the original. I did hear that almost immediately after Series 2 setup. Not having heard the Alexia since I returned, I'll wait to do that before comparing, but as I noted the speakers at David's had a sense of ease that, for now at least, I do not remember from my Wilsons.

 

[tima]

Hi,

The ability of a cone to return to its starting position is basically a function of the weight of the cone itself (hence why say the vintage doped paper cones are so light versus a cone made of carbon or plastic), the force of the motor (that is the magnetic force induced by the motor on the cone) - again the vintage drivers use very powerful alnico or field coil magnets typically, the x max which is the distance that the cone is able to move in this “system” (usually very low in vintage designs) and the stiffness of the suspension of the cone - the vintage drivers often use quite stiff suspension made from impregnated / doped fabric or even leather versus a modern floppier rubber.

Best.

Thanks Bill. That is very helpful to my understanding. Not sure but I vaguely recall the M9500s have neodymium magnets.

 

[Audiophile Bill]

Thanks Bill. That is very helpful to my understanding. Not sure but I vaguely recall the M9500s have neodymium magnets.

That is still absolutely fine because neodymium magnets are able to provide extreme force too - with appropriate poles they can achieve the maximum (theoretical) flux density of 2.4T.

 

[tima]

That is still absolutely fine because neodymium magnets are able to provide extreme force too - with appropriate poles they can achieve the maximum (theoretical) flux density of 2.4T.

Thanks again. Teslas !

This is good. Probably the weakest area of my audio knowledge is speaker technology. You and others are helping me learn how, at least, to talk about this stuff.

 

[Audiophile Bill]

I should have mentioned that woofers rarely use such extreme flux like mids do anyway. I would expect those woofers to be around 1.2-1.4T at a guess. The reason is because you will lose bass as the magnetic force is increased and Q falls.

 

[Audiophile Bill]

Thanks again. Teslas !

This is good. Probably the weakest area of my audio knowledge is speaker technology. You and others are helping me learn how, at least, to talk about this stuff.

I have been playing around a lot recently with field coil motors. It is very instructive to understand and hear how the voltage and/or current applied to the field coil circuit changes the T/S parameters and how that manifests in sound. Of particular interest is that the sensitivity is proportional to the voltage and/or current applied until you saturate the pole. Concomitant reductions in Q are occurring. You hear less and less bass output as the magnetic force climbs but the perceived speed of the driver increases. At maximum the cones can sound like a stat - this is often why you hear people say the field coil sounded stat like. It is that transient start / stop speed they are talking about.

 

[tima]

I have been playing around a lot recently with field coil motors. It is very instructive to understand and hear how the voltage and/or current applied to the field coil circuit changes the T/S parameters and how that manifests in sound. Of particular interest is that the sensitivity is proportional to the voltage and/or current applied until you saturate the pole. Concomitant reductions in Q are occurring. You hear less and less bass output as the magnetic force climbs but the perceived speed of the driver increases. At maximum the cones can sound like a stat - this is often why you hear people say the field coil sounded stat like. It is that transient start / stop speed they are talking about.

This is interesting. I have a field coil based speaker in for review. It has a power supply with adjustable current; I've only gone slightly off the default either way. For now I'll keep the name out of it. Don't want to swerve the thread too far.

 

[bonzo75]

Please play us some videos of classic audio

 

[dcathro]

This is interesting. I have a field coil based speaker in for review. It has a power supply with adjustable current; I've only gone slightly off the default either way. For now I'll keep the name out of it. Don't want to swerve the thread too far.

Very interesting Tim! Please share any insights you get from playing around with the powers supply parameters.

 

[morricab]

I should have mentioned that woofers rarely use such extreme flux like mids do anyway. I would expect those woofers to be around 1.2-1.4T at a guess. The reason is because you will lose bass as the magnetic force is increased and Q falls.

Then it’s perfect for a TQWT or exponential horn!

 

[morricab]

This is interesting. I have a field coil based speaker in for review. It has a power supply with adjustable current; I've only gone slightly off the default either way. For now I'll keep the name out of it. Don't want to swerve the thread too far.

Classic Audio?

 

[Audiophile Bill]

Very interesting Tim! Please share any insights you get from playing around with the powers supply parameters.

This is data from the excellent Supravox 285 EXC. Look at Q and SPL as voltage increases - not small!!

 

[morricab]

This is data from the excellent Supravox 285 EXC. Look at Q and SPL as voltage increases - not small!!

View attachment 92605

Yes huge range. My 215-2000s are 99 db and Qts of only around 0.2. But in a TQWT they make flat to 30Hz in room.

 

[PeterA]

To tell the truth, I had no sense of coherence or incoherence. That means nothing in the sound at David's caused me to take notice of any disjointedness between the lows, mids, and highs. I take that as coherent. I conjecture that part of the ease I described was from my mind not having to work subconsciously to compensate for timing irregularites.

Tim, I had the same experience listening at David's. There was no thinking about coherence or incoherence, nor of other sonic attributes either. The music was simply presented as such. That for me is the essence of natural sound: no awareness of the system per se, just the music, seemingly closer to how it was captured on the recording and originally performed. And this is the quality that my former system lacked to some degree, prompting me to replace it.

 

[ddk]

Tim, I had the same experience listening at David's. There was no thinking about coherence or incoherence, nor of other sonic attributes either. The music was simply presented as such. That for me is the essence of natural sound: no awareness of the system per se, just the music, seemingly closer to how it was captured on the recording and originally performed. And this is the quality that my former system lacked to some degree, prompting me to replace it.

I put a lot of time an effort to setup systems with no outstanding frequencies, the goal has been an impressive system that doesn't impress as a machine and not compete with the music. Happy to hear that you both felt that.

david

 

[matakana]

If I recall their prices used to be much higher before they went direct. Neodio is one of the best sounding players imo.

The NR 22 Dac is also very good.

 

[tima]

Very interesting Tim! Please share any insights you get from playing around with the powers supply parameters.

Thanks. I will share that in the review. Where I have difficulty is finding the better words to describe what I hear.

 

[tima]

I put a lot of time an effort to setup systems with no outstanding frequencies, the goal has been an impressive system that doesn't impress as a machine and not compete with the music. Happy to hear that you both felt that.

Yes, and from what I can tell by my visit is you are a master at it at the system level. Several times in reviews I've written I prefer to use a component that does not cause me to think about it. To be able to say that of an entire system is remarkable.

Recognition strikes me as a mental phenomenon. Sometimes I hear something that really stands out in a positive or negative way.and I have to work to not think about that. Sometimes it is like a seesaw where some music is balanced while other music causes the listening to tip over. For example I find that electronica (Kraftwerk, Trentemøller) - where there is no basis in acoustic music - usually sounds pretty good. Renaissance, Baroque, HIP groups, are a challenge - harpsichords are easy, sackbuts not so much.

Then there are systems such as we heard in Utah - like the Nothing Racks, get one in place and there it is - stalwart systems whose sound is straightforward, pure and realistic, simply there. I sat looking at those Bionors, almost as if I were in a trance -- seeing clearly but the visual was disconnected to my mind, I did not think, I was not distracted, I knew I was listening but I did not have awareness that I was actively listening. For analysis I might say a perception of the classical notion of beauty itself: proportion.

It is hard to find the right words to describe the experience of listening to music without thinking about where it comes from or how it is made. As audiophiles we bring a lot of baggage with us that just gets in the way.

edit: grammar

 

[Folsom]

I'd be cautious about some statements on QTS. For example the woofers used in the Bionors are QTS of .7

Don't get me wrong, I pay a lot of attention to it for types of drives etc but depending on the type of driver and enclosure/horn design the concerns vary.