Here are a couple of links that clearly explain some of the complexity and compromise involved in speaker design. http://www.soundonsound.com/sos/oct00/articles/monitor.htm http://www.soundonsound.com/sos/nov00/articles/ustandingmons.htm |
Rlew, I am only concerned that someone reading this thread will think that a high sensitivity speaker is necessarily better than a low sensitivity speaker. Unlike the general rule about a bigger box having better bandwidth and therefore being a better speaker.....there is no simple rule of thumb for efficiency. There are indeed advantages in high sensitiivity speakers, as myself and others have pointed out, such as a better dynamic range (less compression), however speaker design requires a balance of compromises and high sensitivity is not always better. In very general terms, ultra-efficient speakers should be avoided just as ultra-inefficient speakers should be avoided. Both will have strengths but extremes are generally achieved with large compromises in other areas instead of an overall balance in performance. Let me give a couple of examples of how a manufacturer can achieve high efficiency at the expense of distortion; Long coil operating in short magnetic gap gives a low cost and highly efficient driver but it increases harmonic distortion as the voice coil operates outside the linear area of the short magnet gap. Also the heat dissapation is poor in these designs....so while they are highly sensitive they do not dissipate heat as well as a shorter coil in a longer magnet gap. Very light rigid cone diaphragms made from hard/stiff materials (magnesium,ceramic,polymers). These efficient rigid low mass cones have low internal damping and tend to have high Q resonances. This efficient choice of cone leads to higher harmonic distortion than more critically damped designs. |
Hi Shadorne, I don't know enough to discuss the relative distortion properties of low efficiency vs high efficiency designs, much less their perception (which is what really matters). I would think that some of the techniques used to get high efficiency are conducive to low distortion (such as powerful, symmetrical magnetic fields), and some are not (such as very short-throw voice coils and diffraction horns). Distortion perception is often a level-dependent phenomenon; that is, we often don't hear the distortion until the volume level is sufficiently high. Also, the ear's sensitivity to distortion does not correlate well at all with distortion measurements; the shape of the distortion envelope and type of distortion play a huge role, and simple percentage distortion figures aren't useful. On final point not to be overlooked is that it's not nearly as simple as comparing efficiencies. Box size, bandwidth, and cost also factor in. If we keep box size the same, then as efficiency goes up the bass exension is reduced. If we maintain the same bass extension, then as efficiency goes up box size and cost both go up. Duke |
Efficient speakers v. less efficient speakers If driven with the appropriate amplifier(s), meaning a higher powered amplifier for a less efficient speaker and a lower powered amplifier for a more efficent speaker, are there any difference?rlew01-18-2006 8:28amHuge difference. Like Night and day'/ Black and white like complelely opposites, Like different sound worlds. If you have a xover style speaker, its not really going to matter if you have a 50 watt amp, or a 1000 watt amp. Well it obviosuly will make *some difference* in how speaker responds, But who really needs 100 watts?? AT what db listening levels?? fact of the matter is higher sensitive speakers will perform , = RESPOND, far superior with just about any amplifer , from SETs, to EL34's to Jadis's JA800 weighing over 800 lbs, like some 500 pure class A watts. Whereas with xover low efficiency speakers,, folks keep chaging amps out thinking,,,**well maybe, just maybe if I swap out my amp, I'll get better sound from my system* Wrong. Nothing will fix the fact that lower efficient speakers will wear on your nerves after a while Its only a matter of time.. So then some figure,,,hummm, maybe i should swap out speakers,,for yet another xover low efficient speaker,,,**Yeah now THATS much better,,,** then after some years,,, hummm, just maybe,,,and so on and so forth. Like a Merry Go Round. In the end, they finally try a high efficient wide band,, WOW where have I been. = On the MerrtGoRound. |
gregm3,252 posts01-18-2006 10:47amThe most obvious differences are technical and practical -- not theoretical. In theory, all you need is twice the energy for every 3db difference. In practise however your 90db spl/1m/2,83V will need 1000W energy to reach 120db spl and will have disintegrated long before those watts reach them! That's assuming you have 1000Watts available to you, of course. So, higher sensitivity allows dynamic headroom with reasonable requirements -- say 50-100 watts amplification. Indeed, if you have REALLY sensitive speakers, you can get away with less than 50 watts energy -- much easier to find than 1000 ~~~~~~~~~~~~~~~~~ Yep, That pretty much sums it up. Low efficient speakers all hundreds of them, have major issues. And suck the life blood out of the amp's ability to voice beautiful music, I have no idea whoever started these xover designs. But I sure wish they had not. WE should have stayed with the 1929 Field Coil Full Rannge concept ONLY and no others. Xovers are nothing more than a marketing scheme. And we all took the bait, Hooked. WEll I bit the line. There is not 1 xover design that even slightly interests me. Even if FREE. No thanks. Donate the Wilsons to charity, I don't want them. |
