I am talking about the av. The people who had problems (2 of them at least) are very knowledgeable. Certainly more knowledgeable than me. There was a ton of debate over at CAF, nothing solved the issues. Even John couldn't fix the issue, he just kept sticking to the fact that the box was wrong although that was the exact spec box that he had recommended. It made John seem very shady.
IIRC all of John's driver's are designed for both home/car use. Some are optimized for one or the other. The subs in question that were used were supposedly good for car use.
Nothing can be wrong with a box to make it not play high. 60hz and up is all driver effeciency the AV's are over 90db/1w/1m and have super low inductance they WILL play high, up to 2k with that effeciency lol. If someone had an issue with them not playing high, or seeming like they didnt' is because they had ALOT of cabin gain down low and it makes their top end seem quiter. One person who had an issue IIRC, was using 3 cubes+ tuned at like 33hz and didnt' use a subsonic. Yeah, that is going to be a sorta boomy on the low end, especially if your car has alot of gain near 30hz. No car has massive gain up at 80hz, most vehciles have a suckout somewhere between 60 and 90 actually. The guy bitchign about a lack of ouput at 60hz also faced the woofers toward him and didnt' block off the backwave. That's also generally going to cause a suckout somewhere up in that region too. The problem wasn't the subs I can promise you that.
Anyway I've used subs that **** up top. My last sub was an AA avalanche, known for ******* up top and it did. Even a single adire koda 10 had more output from 50hz and up. My current subs are actually 2 AV15h's. Box is 4.7 cubes net tuned at 25hz. Same car as my lowish effeciency Ava with no shorting rings was in The subs are are currently passed at 125hz at 24db's/octave. They play easily to 20hz, 20hz moves my rear deck and back seats 2 inches. They also play 125hz loud enough to keep up with my 97db/1w1m midranges and horns, my fronstage is FAR louder than almost anyone on this forum in the midbass and my AV's keep up fine. Above 125 the subs drop off hard and fast. Why? Because the rear deck holes are only big enough to let in 125hz and below without acting as a lpf. Also I have a good amount of gain at 125hz in my car and actually EQ it down on my fronts.
Anyway john never insisted the box was the issue. He insisted people are looking for something that doesn't exist. If you build a ported box tuned low in a car you WILL NOT get flat response up until 80z. Cabin gain makes that an impossibilty. I have to cut 4-5db's to get a flat response in my vehicle and I dont' have the world sbest gain by any means. If you want a somewhat flat response out of the box an AV15h sealed actually does a good job. It begins rolling off by 65hz so it will counter cabin gain, that plus it's high effeciency up top lead to flatish response with no EQ.
If you know how to work around cabin gain then the AV's are fine for car use. They do great in smaller ported boxes as you can port them, tune low and not end up beign super boomy with cabin gain included. Yeah they'll have a strong low end, but not a 15db peak like you get with say a DD sub or AQ. They still have a slowly falling response even ported, ideal for car use, either H or X. People seem to think car audio drivers are actually designed to sound good in a car, they aren't. Car audio branded speakers are designed to do one thing, take abuse because most car audio fans are dumb and run 2x rated power and no filters on everything. If you run t/s specs and model most "car audio" subs, they shoudl sound like **** in a car and most of them do. "Ideal" boxes are really just boom boxes that will slam between 34-45 and then pretty much die. At least in the boomer crowd category, the "SQ" subs are the exact opposite. Small sealed box with a terribly high Q so all sorts of ringing and even cabin gain won't fix the lack of low end. However, the coils can stil handle 2x what they claim thermally and you can't bottom it out in a box that size.
Anyway not trying to come off as a **** on any of this, it's just frustrating to hear misinformation about this whole thing. There is no magic trick to make a sub play up high. It's simplyit's baseline effeciency and how much power the coil can handle. Other than that you just have to balance out how much low end the box gives you with how much cabin gain you have. Cabin gain is mostly down from 50 and down, so that's where you don't need as much bass from the box. AV's are actually very good at giving this response assumign you face your box either towards the tail of the trunk to prevent 60hz cancellation (true of ANY sub) or face it forward and seal off the back. (SPl competitors do this alot). This is basic car acoustics that has pretty much been shown to be true 99% of the time. The AV woofers have T/S parameters that make themselves very good for car usage, both for SPL or SQ.
Anyway thermally the AV's will take alot fo power. 1200 watts if you keep excuriosn under control is fine. Mechanically they have soft spiders, most car audio companies use stiffer spiders because they know most PPl dont' set gains properly or SSF's properly and will overpower/bottom them out. That's Nicks general trick as far as I know. Build the suspension hard enough it takes alot to bottom it, make it soft bottom when it finally does and his fans are destructive and he knows it. Also make sure it can take 2x whatever you rate it it without melting.
