| rdrysdale wrote:|
| I mean that with a horn loaded compression driver, a strong motor, and a very light diaphragm, the attack and transients are more life like. Because the diaphragm can more precisely follow the recorded signal, the reproduction is more accurate than you would get from a weaker motor and a larger, heavier diaphragm, which describes most direct radiators. |
Well, yes and no. At least it is how I feel, or at least to continue to play the devil advocate.
The idea of “a stronger motor and a lighter diaphragm” is intellectually and logically sound rational but it is not necessarily correlates with what I call “Applied Sound”. The motor should not be “stronger” it should be strong enough to create a saturated flux within the entire run of voice coil. Should it be stronger? I think, saturation is a binary state and since it reached it the further enlarging of the magnetic force become pointless. Someone might say that the excessive magnetic force is necessary to combat the flax modulations… one again… yes and no. You see, with bass everything is kind of twisted. I detected that slightly discharged drivers, although they do not hit the nominal sensitively, but they produce better quality sound if to pay attention only at the low frequencies. Furthermore, while I made many experiments field-coil drivers I learned that lowering the DC voltage that supplied to the magnetizing coil made bass way more interesting and natural. So, the idea of “stronger motor” is not necessary an absolute truth as far as I can see/hear it.
Now about the “light diaphragm”. Yes, there is nothing wrong to pursue the lighter mass of diaphragms but, once again, I do not know if this rule is absolute truth for midbass drivers. The bass transducer by nature has larger excursion and therefore larger inertia. We can minimize the inertia by lowering mass but it not necessary successful because the inertia itself is not a problem but the suspension that cares the inertia. We could cancel out the suspension’s influence (by implementing an infinite damping via negative output impedance for instance) by we pay for it by introducing other aggravations (burning a lot of power and forcing the amp to switch into “AB” for instance). So, why people think that the lower mass diaphragms would necessary is more responsive if the permeability of diaphragm is mostly the property of the diaphragm’s suspension? I kind of approach the vision about drivers “as a whole” and I feel that as much as diaphragm should be aware about magnet as much as magnet and entire driver should be aware about the diaphragms and it’s suspension.
Pretend that you play tennis. If you have your rocket too heavy with too strong strings then you could shot the ball faster, however you loss control over the ball and loose your ability to spin the ball. The minute satellites of your hand is feeling and reacting to the ball will be lost and you send to the opposite side of the court juts very fast, very heavy BUT very identical blasts. Dose this keyword “identical” or “generic” make you to wonder? I feel that very same happens with a driver when it has too light diaphragm, too strong motor and too irrational suspension. Now is the key: there is no such a thing as too light diaphragm, too strong motor and too irrational suspension – they are all connected. Not only they but many-many other things: elasticity of the diaphragm, it’s ability to propagate different frequency with different speed, the late reported by Bud boundary effect, the cone’s ability to bend at different frequency with different rate, the type shape, material, winding techniques of the voice coil, the numerous aspects of suspension and many-many other things, to many to name. The problem is that there is not universal formula where all those ingredients could be described - all of them work in conjunction. We, everyone (!), still make drivers completely blindly and receive better sound mostly by chance. Certainly there are some ideas: which direction might bring better luck, but still it is hardly manageable process. We could make out driver to hit some specific characteristics but we can’t not predictably to make them to do sound in a way we would like to. Furthermore, when we stick a driver into a horn and then place the midbass horn into a room then we introduce so many others conditions that…. to simplify everything juts by suggesting the “strong motor and lighter diaphragm” would be similar to believe that a healthier life-stile would prevent a person from being killed in a car crash. :-)
I’m having now a number of people who build horns for themselves and they keep asking me to give them fixed recommendations how to get the specific sound. I always hesitant to reply unless I know the exact driver, the exact horn, the exact amps and if I personally was in their specific room. Still, my confidence in the case of me perfectly family with all those conditions will be not my real ability to predict the things but only my self-mockering arrogants. I always suggest to my guys to do the specific experiments and to see how their specific installations will comply with specific sonic characteristics - It never possible to predict what will happen, and practically if a listener has the real honesty with him/herself and objectivism with the results. BTW, your pal Bruce Edgar, if to strip out of him his explainable tendency to shove 1/16 of truth into the asses of the semi-Moronic customers of his and if to dig him slightly deeper then the pop-intelligence of the AA’s idiocy then he indicates the very truthful behavior toward the midbass horns. He does not believes that any rules exist and the practice of a given inhalations is always unique and exclusive exprence.
I think what we do with midbass horns is we build the best we can, using the best of our knowledge and exercising the best out ability to react to the results… and then we (including me) begin to build the speculations and justifications why our way was the “way to go”. I think this behavior has nothing to do with real altruism to the subject but rather it portrays our egos and our desire to see our semi- pathetic accomplishments as a part of immortal efforts…
Sorry, but the “stronger motor and lighter diaphragm” does not sound to me as an inclusive explanation….
Romy the Cat
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche