REL vs JL AUDIO

manelus, I hate to be a stick in the mud (ya right) but, speed has nothing to do with it. When a driver can not move fast enough it's high frequency response rolls off. Look at the frequency response of the 18" Dayton I mention above, 20 to 500 Hz. It has no trouble putting out 500 Hz so 80 to 100 Hz is not a problem. Most 12" drivers make it to 1000 Hz without issue. It is usually not speed that cuts the drivers off either but cone breakup. So, then what are you hearing? Transients and detail are being smeared because either the subs were not well match to the main speakers or the amp driving the subwoofer was not able to control it well.
Driving big powerful subwoofers is not easy. There is a lot of back EMF.
This is a problem we noted way back in the late 70's when subwoofers were a brand new deal. Some amps made great bass others not so much. Basically you need a lot of power (big power supply) and an output stage with extremely low impedance. The class D amps that most of the Subwoofer manufacturers are using usually do an admirable job but IMHO not as good as a big class A/AB amp. But, in a small enclosed space you can't have a big amp that generates a lot of heat.
By the way, if vibration affects electronics why are we sticking amplifiers in subwoofers? Just a thought. I prefer passive subwoofers and outboard amplifiers. With outboard digital bass management there is no need to place electronics in the subs. You can then pick the amp you think makes the best bass.  As far as matching subs to main speakers is concerned, the vast majority of sub owners are not able to do it correctly because they do not have the tools. Doing it by ear is folly. It's like pinning the tail on the donkey. It is easy to do if you take off the blindfold. Using a measurement mic/program along with digital bass management allows you to dial it in perfectly every time regardless of where you place the subwoofers and boy do you get big smiles when everything is working right. 

Subwoofers are neither fast nor slow. They are either driven and integrated correctly or they are not.

Don't get me started on enclosures.

2 for the REL CARBON SPECIAL!!! Thats where I'm leaning!! one to start, they aren't cheap. REL for the win!!! 

I was never interested in adding subs to my 2-channel system. However, I decided to try some REL T5i’s to complement some stand mount speakers I was trying. I was really impressed with how they filled in the low end, improved the soundstage and integral easily. I recently moved and my room is a bit bigger so I decided to try a JL F110 v1, with the goal of likely getting another. I really just moved two weeks ago and just set up the JL and haven’t dialed it in at all. It obviously goes deeper than the T5i’s but other than that it is too hard to tell yet if I like it more. I’ll report back as I dial it in more. I’m still just dialing in the whole system so it might be a few weeks. 

mijostyn5,059 postsSome of the information I agree with you but when it comes to speed and accuracy with the subwoofers, I don’t. It has to do with time alignment with the speaker of choice. You want everything to be in tune, exactly how it is produced. If the sub is ported, it doesn’t require as much power as a sealed subwoofer. If it is a push-pull subwoofer with 2 active or 1 active and 1 passive, it reacts a bit faster and requires less power. I will agree from experience that a class A/B amplifier subwoofer sounds a little better but that does depend on the build. JL, REL, M & K, etc have been in the game a long time and have mastered the Class D amplification. JL started in the car world and now dabs in both home and auto. The subwoofer that’s in the Fathom subs which are my favorite are W7 10”, 12”, & 13”. During the time when a JL representative was on a video chat at HIFI Buy I asked if they have considered utilizing their W7 8” in a single or dual  for their Fathom or their Gotham. He answered that it wouldn’t be cost effective to build but he does understand the want for it. The 8” W7 is their best seller in the car audio world. I’m not a fan of Bose but think about how they figured it out utilizing 5” subwoofers. The cabinet design also plays a huge part. 

I have had 2 JL Audio F112 v1 for a long time now, they are pair with Wilson Sophia v1, I use a Trinnov AL16 to do bass management, they are brilliant and build quality is tops. I have used them with multiple setups, tube and SS preamps. If you take the time to do the setup with location and built in room correction, they are solid addition to any setup.