Subwoofer failings and their use-related reasons

+1 geoffkait

jon_5912 raises a great point. I went from a single 18 inch to dual 12 inch
subs. I am not unhappy with the 12's mind you, but I do miss the 18 for the very reasons jon_5912 pointed out, If I could do it again, I would have opted for a 15 or 18 inch pair. As brutal as a sub environment is,
I think generally speaking they are highly reliable.        

I've owned my pair of ACI Titan subs (12" driver; plate amp) for many years, continuously powered on, and have not had any issues (knock on wood). However: I am no bass freak, their freq. response are set with intent of being flat; I don't use them for HT, only 2-channel music; peak volume rarely exceeds 95 db; and while I play most all music genres I rarely spin any rap, electronica, or other bass-heavy type music. In other words, never abused or pushed to their limits.

All things fail most commercial offerings are designed for up to 10 years use. I design and work with many types of transducer including some of the largest and most powerful ones. Placing a amplifier and massive transducer in same cabinet is sub-optimal design and the main reason  is the vibration stress on electrical parts. Quality manufacturers address this issue to some degree but it is all about cost cutting subwoofers are hi profit items. We can sell you a MDF cube with one driver and cheap amp for a good amount of $.  The smaller the transducer and cube the more power and excursion required to produce low frequency thus more chance to fail..

I must be doing something wrong, I’ve never had a sub fail on me. Home audio, car audio, in almost 20 years of owning different models. I can see if subs are continually pushed close to their limits, or abused, then I’m sure the failure rate would go up. But that’s pretty much true of most consumer rated gear.

My strategy is typically to buy more sub(or amp, etc) than I need. Those that buy the lessor option and then overdrive it to compensate get what they deserve.

In a direct comparison the JL f113 appeared to be very nicely constructed and subjectively and very impressive close second to my DD-18 in its sonic presentation at that time. I think its important to point out JL Audio's almost instant periodical and boutique audio popularity may be responsible for a large population of the brand in our community along with an increased instance of failure discussions. The actual failure percentage may be nearer to many other brands. Your failure may have been addressed as an updated part or in JLs newer version. 

An observation I made when replacing my Velodyne DD-18 with two irregularly placed DD-12 Plus. I ran the Auto EQ program through all three units. The amount of cone travel between a single 12 appeared greater than the 18. After the Auto EQ procedure for the two 12s combined their cone travel was now less than the single 18. The amount of gain equalization was also much less with the two 12s. Most of the room nodes were eliminated giving a sense of improved room loading and an overall more enjoyable presentation. I would assume two 18s would decrease driver excursion further.

JohnK makes a huge point regarding internally mounted electronics, the idea simply flies in the face of fundamental audiophilia isolation.