NDMstang65

Why do you people do this? Make stupid comments to humor yourselves. Some subs will work well with say 500 watts, but they can handle quite a bit more...like 1000rms. Will the Fi Q perform well with 500-600 watts rms in a sealed enclosure. No need to tell you the power ratings of the Linear Power 8002SW. The amp is a monster and if you have never heard of it, you haven't been in car audio very long. It's a legend. Linear Power are pretty much top of the line when it comes to car amplifiers and are the most under rated of any I have used in the past 20 years. I do not know what kind of power a 15 year old amp does. I have heard of linear power..I have had some of the stuff years ago...we've wound custom coils for a guy who has a bunch of old linear power amps. I do not know how much power that amp does...which is why I asked. Again, How much power does it do? At what impedance?

I guess a 'minimum' would be 1 watt What kind of power does that amp do?

Is he loosing the back window? Or is he just cutting the bed?

You do not have to use that glue. Go to home depot and get loctite 15 minute epoxy...works fantastic. All you do is put the epoxy on the spider landing and surround landing and put a little bit of weight on the cone to hold everything down. Put the gasket back around the edge of the surround so it is held down. I've built many many many recones with that epoxy

What is your email address???

No shims...we're probably going to add glue to the website shortly and you can only purchase it when you get a recone kit.

Might change something 18 times in the next 2 minutes... We never say when we are going to change something...it just 'appears'.

Put it back in a magnetizer and charge it again..so you are good for another 300 years or so

You can put it in a .00000001 cf sealed box if you can get it to fit...it doesn't mean that it is going to sound right. We highly recommend sticking within the guidelines that are in the 'Tech' section of the forum and the website.

You've got another 298 years before it will start loosing force...

No there is not any signature required.

Lord no not getting upset by any means . It's not just the JBL amp. The reason I am bringing up the JBL amp is because it does the same power no matter what resistance is thrown at it. I simply do not have an answer for it...or as to 'why'..but I know what the end result is . The stetsom amps and the SounDigital amps do it as well. I've seen the Hifonics Maxximus do the exact same thing... Even going back 8 years or so with the old EQ PHD2 Shredders...I wired them to .25 ohm with the Quad 1ohm coils that I had on a pair of HC's and shot holes completely through the formers on a burp...wasn't clipping anything either, it just popped the coil windings like fuses...

Exactly what I meant. Modelling the stock BTL shows me that I'd never even think about using it for HT without a BFD or other extreme equalization. It'll swallow that 2500w though If I were building a box for it I'd shoot for a lower tuning, you don't lose much output as that sub has excursion to give and you will get something that will thunder the lows. You'll have to roll it off up top though. 12Hz should be fine. *Caveat is that the rec'd/model I did was for the T/S on the site Which is why I'm dead set against modeling things and taking them as the second coming of Christ. It would give you an idea..but it doesn't sound anything like it 'should'...sounds quite good actually.

It wasn't only the back EMF...it was the sheer fact that all of the parameters were shifting because they were only using 1/2 of the sub at any given time. Hence the clamp to short the coil so the parameters stay within spec. Dead mass hanging out there...changing the Fs..Qts..Qes..Qms..etc etc etc....you go from having a midbass driver on crack to something that has no motor strength and sounds dead/lifeless like an old H2... If it did not matter to the sub explain the crown amps that we tested/used in Mike's van... It is the EXACT same power. 4ohms..never hurt a coil..ever. We did testing at 1ohm in the 'High Current' mode with the crown amp and the voltage and current flopped positions...and effectively shot holes 1/8" diameter through either the top or the center of the coil. The power supply is by no means 'weak' and of course they can handle it. The coil is what can not handle it. The motor controlled H-bridge amps I think are running into taxing issues on the rails and possibly the camps aren't filtering all of the ripple of the power supply out...possibly kicking some DC into the coils when they start wiring them down below 1ohm. We've got a couple guys running the stetsom and sound digital amps and they are starting to do the exact same thing as the crown amps did in 'High Current' mode... I ran the amps like you have like that as well...as Loyd and I had the original prototype 20.1...we could run it like that. The rise was also well above 1ohm. The lay people do not need to know that. It is like giving a 7 year old a can of gas and a pack of matches and telling them to not let anything on fire. If you do not give them the gas and matches and just a brick..odds are they won't set anything on fire in the first place. They might break a window..but at least they won't have an arson charge on their record :-P. When you get the new vehicle going you may have a different impedance rise than in the van...and you may not be able to run those amps like that...you may start shooting holes in coils. I've seen it one too many times, i'm not about to condone people to wire things like that....the majority does not know what a subsonic filter is anyhow and that is bad enough as it is

Right...but the problem in this instance is not that. It is that people are using 'motor controller' style setups that are nothing short of nasty...Kicker is an exception for doing that by shorting a coil when things reverse... They're slamming back and forth on the H-bridge and having all kinds of problems... Your math is without a doubt right...no doubt about that at all. But that is simply not how it works..read below. Put an A6000GTi in 'High Current' mode and shoot the windings straight off of the former. (More current than voltage...causing more heat and the coil to fail) Put it in "High voltage" mode...and it makes 8643 watts of clean power...and never ever hurt a sub. Never..EVER EVER run a sub below 1ohm with a high current amp. You'll shoot holes through the coils either at the top of the winding or right in the middle of the coil. I've been there and done it one too many times...but I do not have an answer as to 'why', given power is power and the current stays 'constant' throughout 1 coil.... We're seeing the same thing with many of the H bridge amps... The math is correct...but in reality it isn't how it works

It was at one time...i get curious and flop things out from time to time

The * is with the Hixmax coil... http://www.hometheatershack.com/forums/fi-audio/16903-built-new-box-house.html I've got a down firing power port that polk has a patent on that I built for it..works great. Join the community..they have a great bit of information there.

The BTL is most definitely not in there. Not on Fi's site either which is exactly why I said what I did. Understandably though because if noobs had them it would create more confusion than it would solve. The parameters are on the site... BTL18 DUAL 1 | DUAL 2 Fs: 31.9 Hz | 31.1 Hz Re: 0.7 Ohms/coil | 1.4 Ohms/coil Qms: 6.26 | 6.42 Qes: .26 | .24 Qts: .24 | .023 Mms: 313g | 329g Sd: 1210cm^2 | 1210cm^2 Vas: 163.1 l | 163.1 l Spl: 94.9dB 1W/1m | 94.9dB 1W/1m Bl: 18.3 N/A | 27.2 N/A Xmax: 28mm * | 28mm * Rms: 2000W * | 2000W * Sealed box: N/A cuft | N/A cuft Ported box: 5-10cuft | 5-10cuft Sub OD: 18.500” | 18.500” Cut ID: 16.750” | 16.750” Mounting depth: 10.250” | 10.250” Displacement: 0.26cuft | 0.26cuft Standard 3-7 business day build time. Product code: 00218 Price: $ 414.00

Do not run them at .5ohm...BAD idea. Many people think "Well i can wire it at .5ohm and get way more power"...which is only partially true. Yes less resistance = more power. However, below 1 ohm you are attempting to put out more current than voltage. More current = more heat. More heat = broken sub(s). Don't do it. It is WAY too hard on stuff.

D2's are the universal gap... D1 gap is specific for the D1 if otherwise not ordered like that.. Generally best to get the universal.

In a car you really do not have to follow the 10 x vas rule that is 'typical' for an IB install in a house/home theater. If you can physically mount a pair of 18's then go for it 550w is enough power to get one to full stroke @ 20Hz. You do not have to vent them or anything as far as to the outside...I haven't ran across a car that can fit a true IB manifold for a pair of 18's behind the back seat that is sealed off from the front wave. Also take note that if your goals are for something to be 'loud' an IB install is not for you. They blend great and sound great..but output is FAR less than another sub in a regular ported or even sealed enclosure. Of course you would have to bump power up as well if you were planning on running a pair...~1 kw would be ample. Some people buy IB woofers and simply do not know what they truly are and throw them in a box because they are cheap. I just want to make sure you know exactly what they are, they are not as overbuilt as the other woofers and they are more delicate.

So what would the issue be? We've got a cult over at home theater shack that use a bunch of them in various HT installs..as well as quite a few guys that run them in IB installs in SQ cars... Most of them do not come on any forums..

You also have the T/S parameters which I would never recommend designing a HT sub without. Balancing LFE, power handling and cone excursion isn't so easy otherwise and you'll end up with a compromise that could be rather detrimental. But obviously considering the OP now has an answer 15cubes at 15Hz. How much power? Bash 500..couldn't afford the 1kw at the time. Some of our OEM work is in the HT field..and gets rave reviews from big names...

Overdriving and clipping the amp...and the subsonic filter on that amp isn't much count either...

If it has been that long..probably didn't get the second one. Sorry about that..shoot me an email [email protected] Odds are every question that you have is already answered in the tech section on here...