So you wanna change your sub...

tallrd

Member
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03 MSP Mica #369
Got my JL 8W3V2 (2 ohm version) in last night. Short version: it's a huge difference in sound quality, but the same aprx sound *quantity* (i.e. spl). I'd say it has at least an octave better LF response than the stock Kenwood.

Long version: As I was trying to take the 8 screws out which held the Kenwood sub in, 4 of them stripped; stripped to the point that I couldn't get any screwdriver to catch. Mazda must have saved a couple pennies on those bad-compound screws--way to go Mazda! (gun) . This required me to manually drill out each stripped screw and replace the threaded insert which the screws go into. That caused me to take WAY longer than I wanted for this job (1.5 hours total), but the sound is a big difference and therefore worth it.

for those curious, I didn't invert my amp so if it blows then I guess it was meant to be. The amp kind of "blows" already anyway.
 
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i did the same thing wednesday night. i love the sound, definitely a noticeable difference. about the screws thing.. mazda decided it would be a great idea to use the screw locks on them.. most people have to drill them out. i didnt, however. looks like the sub blew on it once already and mazda replaced it without using the locks. either way, its a nice little upgrade for the money :).
 
goku4658 said:
2 ohm version? i thought we were supposed to get the 4ohm one
He probably meant the dual 2ohm coils, wired in series for 4ohm.

I just received my RF Punch stage 2 8" that will be going in hopefully tonight, I think I'm gonna have to use new screws. Considering I'm missing 4 of them, and I noticed some of the insert things are loose. I can't remember what it looks like right now, what exactly are you guys using for screws? Argh, I suck at this kind of thing.

Tallrd: you say you get another octave or something, so what do you have your NF cutoff frequency set to now? Just curious what would be considered a good setting.
 
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peepsalot said:
He probably meant the dual 2ohm coils, wired in series for 4ohm.

I just received my RF Punch stage 2 8" that will be going in hopefully tonight, I think I'm gonna have to use new screws. Considering I'm missing 4 of them, and I noticed some of the insert things are loose. I can't remember what it looks like right now, what exactly are you guys using for screws? Argh, I suck at this kind of thing.

Tallrd: you say you get another octave or something, so what do you have your NF cutoff frequency set to now? Just curious what would be considered a good setting.

Yes, you are correct that these are to be wired in series to obtain a 4 ohm load from the amp--exactly correct for the speaker. JL even encloses instructions on how to do the wiring on your own. As for he bass response, my xover point for the fronts are at 80 (12db/octave i think), my rear doors are cut at 60hz, and my sub is lpf at 80 hz. For an 8", you can get away with a 100hz/120hz xover point, but it's not as efficient imo. That said, the xover doesn't have anything to do with the speaker's frequency response. The speaker out of the box just has better LF response by design.

And I've kept my amp in the stock position; some have stated that to be safe you should turn the amp upright, or put a fan on it. I'll admit that it gets pretty hot now, but hasn't cut out once.
 
I'm going to try to keep my amp in the same position too. I removed the little Kenwood label plate on the amp because I think it obstructs airflow to the heatsink fins. Probably doesn't make that much differeence, but I just didn't like it there.

So what exactly are you using like some kind of drywall anchor type things to screw into?
 
peepsalot said:
I'm going to try to keep my amp in the same position too. I removed the little Kenwood label plate on the amp because I think it obstructs airflow to the heatsink fins. Probably doesn't make that much differeence, but I just didn't like it there.

So what exactly are you using like some kind of drywall anchor type things to screw into?

not exactly. I took out a stock one, went to my local Menards (hardware store, etc), and to my surprise they actually had the exact same thing 1 size bigger. So I just got the matching screws of the approriate length and everything went well.
 
titanium speed said:
**** that pussy 8 inch sub, i put 2 10"s in mine and just wired my amp on the rack to my box.

Wow way to go buddy. You manage to go off-topic AND be an ass at the same time. (crazy)
 
jersey_emt said:
Wow way to go buddy. You manage to go off-topic AND be an ass at the same time. (crazy)

lol. yeah, I might have been a bit more eloquent in my post if that were me. But, hey, that's just me; what do I know. Besides, this thread was intended those who WANT the 8" sub and not for those looking to run an aftermarket box with over 2X the power requirements from the stock amp.
 
BTW do you guys know what wattage is ok for the stock amp, I was gonna set the gain on it. I hear the rating kenwood gives it is a little inflated? 250rms supposedly. My sub is rated at 200Watts, you think the amp can do that? And you think I can really run 200 all day on the sub if that is the rating they gave it?
 
peepsalot said:
BTW do you guys know what wattage is ok for the stock amp, I was gonna set the gain on it. I hear the rating kenwood gives it is a little inflated? 250rms supposedly. My sub is rated at 200Watts, you think the amp can do that? And you think I can really run 200 all day on the sub if that is the rating they gave it?

It depends on what the impedence of the sub is (how many ohms). If it's 200W @ 8ohms program then no way. If that's 200W @ 4ohms program, then you are pushing your luck on blowing one, the other, or both. It's my undertstanding that the stock amp is 125W @ 4ohms bridged (which is so tiny it's almost hilarious).
Subs by nature love power, so underpowering a sub is never a good idea. The JL and Rockford-Fosgate both make replacements for the stock sub which rock and work well with the stock amp. If you want more SPL, replace both the amp and sub.
 
Well, I have the RF Punch stage 2 4ohm, and RF says it's 200watt rms.

So you think I should set the gain to pump out 125w with this amp though?
 
peepsalot said:
Well, I have the RF Punch stage 2 4ohm, and RF says it's 200watt rms.

So you think I should set the gain to pump out 125w with this amp though?

the sub might die before the amp depending on your listening levels. Either way, it's pushing it (at least that's how it looks on paper). I'd ask someone else on here who is actually using the sub you have with the stock amp. Experience is a better teacher.
 
lol. yeah, I might have been a bit more eloquent in my post if that were me. But, hey, that's just me; what do I know. Besides, this thread was intended those who WANT the 8" sub and not for those looking to run an aftermarket box with over 2X the power requirements from the stock amp.


um no actually im not running over 2x the power requirment, the amp is just fine for the subs that i am using, learn something about sound systems before u post. bud.
 
titanium speed said:
um no actually im not running over 2x the power requirment, the amp is just fine for the subs that i am using, learn something about sound systems before u post. bud.

A very well thought out post indeed. Sorry if you feel I don't anything about the subject which I have posted (check the subject of the thread "bud"). The forums are for users to *help* (key word-->"help") other users. If you are looking to make enemies, you are doing a fine job in short time. You might want to try a different approach seeing as the forums aren't made to make enemies, but help people with a common interest. Think about your next post.
 
peepsalot said:
I was gonna use this method here, set the volume to the max that I will ever play it at when setting it up:
http://www.msprotege.com/forum/showthread.php?t=103524&highlight=gain+amp

So my listening levels shouldn't matter, I'm going to set it so that it can only put out xxx watts at max volume, where xxx is whatever number I decide is safe. If you think the amp is good for 125 then I think I'll try that.

sounds like calculated odds which are more in your favor. Let me know how it works.
 
tallrd... my jl8w3v2d2 is coming tomroow... any other tips as far as the install goes? u jus removed the 8 screws? besides the bad stripped stuff any other quirks to look out for?
 
skilletrx said:
tallrd... my jl8w3v2d2 is coming tomroow... any other tips as far as the install goes? u jus removed the 8 screws? besides the bad stripped stuff any other quirks to look out for?

yeah: make sure to stretch before installing it. :rolleyes: I was super sore the next day from bein' all twisted up in the trunk for an hour. Seriously though, I'll just reitterate that you need to be careful when you take out the stock screws--it *SUCKS* to drill those out. Also, you will not be able to use the stock grill. If you want to have a grill on yer new one, JL makes one specifically for that sub. Good luck mang
 
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