Originally Posted by R Smood
A friend of mine had some thoughts on this discussion and would appreciate your insights.
He recommends against 2 bigger subs vs 4-8 smaller subs arguing that.
1. Bigger subs have bigger moving masses and thus their voice coils tend to overheat more causing more distortion.
2. Bigger drivers (18 inch) will not be as stiff as a smaller driver (10 inch) and thus more susceptible to distortion.
3. The cone area of 6x 10 inch drivers would be similar to dual 18s thus it should extend as low and have as much impact as dual 18s (although of course we are talking quad 18s or maybe even 8x 18s in the case of S72 Ipal).
One counter to point 2 that comes to mind is that a larger driver would move less to generate the same SPL as a smaller driver so that may mitigate any potential distortion of the bigger driver.
Your friend is wrong, as simple as that. The Ipal 18's have lower distortion than just about any other subwoofer driver made, regardless of size. They also have much lower distortion at much higher SPL. They are better in every way. And their voice coils are designed to be able to handle extremely high power for long periods of time without overheating. That's why the JL Audio E110, a $1500 10" subwoofer, had terrible thermal build up after a few frequency response sweeps that showed up in a repeat low level sweep that varied significantly from the cold sweep due to the massive heat build up. The pro audio drivers on the other hand, since they are better in every way, perform flawlessly when repeating a low level sweep after pounding them with much higher maximum output compression sweeps.
Also, just basic measuremetns, i.e. facts, prove your "friend" wrong. Plenty of pro audio drivers have been extensively tested on data-bass. They have incredibly low distortion. You have to accept the fact that old audiophile myths that aren't based on facts are just that....myths. People believed for a really really long time that the world was flat. Doesn't mean it was true. Nowadays, the truth is out there and pretty easy to find. You just have to stay away from the subjective audiophile hangouts that spout a bunch of fairy tales.
A real world example. The BMS18n862 18" driver has distortion less than 1% at a 110 dB drive level. It is one of the lowest distortion drivers ever tested on data-bass, which includes some very high end 10 and 12" designs. Lower distortion than the $1500 JL Audio E110. The 18" BMS driver has 20 dB more output with *lower distortion*. So even if you stacked up 8 of the $1500/each JL Audio E110's, you would have less output and higher distortion than a single 18" driver.
Again, the facts are out there. Smaller drivers are not better. In any way other than being smaller. However, if you ignore evidence, further evidence will continue to make no difference. Go with JL Audio, you will get less performance, lower sound quality, higher distortion for more money.