I am lookinh to buy a 15" Alpine type r (Alpine SWR-1542D (TYPE R) and want to power it with a Kicker 08zk750.1 amp. I have read in several reviews though that the amp has a Variable low-pass filter (50-200 Hz, 24 dB/octave). Would this defeat the purpose of having a 15 because of the frequencies it cuts out, or would it sound good?

 

Absolutely not. If you don't turn on the low pass filter (IIRC you can turn it on/off on that amp) then the subs will sound muddled. Even though the subs are rated to play at a frequency beyond what the amp's LPF maximum, usually it won't sound as clean if you leave the LPF off. Try it for yourself.... you have to tune the amp's LPF crossover to a point to where it sounds great at any point - at which beyond that it sounds distorted. Then what I usually do is set it just a tad bit higher (about 10hz higher) so it doesn't cut of right before the highest frequency.

You don't need to worry about higher frequencies than that.... your mids and tweeters should take care of the higher frequencies, and besides, they'll sound better while doing it than your sub will.

 

The purpose of a sub is for bass, sub bass. Subs shouldn't be played much higher than 80Hz. Since you are asking this question, do you even need a 15? You'd probably be better off with a 12 at most.

 

i thought they were lower notes not higher im a noob when it comes to technical stuff about car stereo. I do like the sound of 15's i just read the only bad review there was for the amp and it talked about how that affected his lows. Thanks for the help guys, im going to go with this amp then. It is between this setup or a 08zxkicker1000.1 and two 12" 2ohm type r's which one would you guys choose. People say the 15 will be sloppy, but i listen to mostly rap and i like deep bass. Is it going to sound very sloppy with a 15?

 

personally, i don't like the type r subs at all... i think they sound muddy period. I would look into a smaller sub and just go ported if you want the big boomy bass of a 15... I can give you plenty of ridiculously loud smaller subs... plus most of the way a system sounds is the install, not the sub... My 10 is louder than a lot of people's 2 12's and it can get quite a bit louder if I chose to port the box, rather than running it sealed for music with double bass.

as for the amp, i think you're mistaking the low pass for a high pass... the LPF is the top cut-off for signal. you're going to want to play around with this. Mine's at 80Hz with my T110, and it sounds great.

 

why not a ported 15 though i think they should sound pretty good what do u think of the boston acoustic g-5

 

I would look away from the mainstream names... check out caraudioclassifieds.org for some advise... My next woofer will be an Ascendant Audio Havoc 12". Some other (pricier) brands are DC audio, RE audio, AA, etc. Just check out what guys are running on there, and if you need help, there's tons of info...

As for a ported 15, that box is going to have to be huge... especially if you're wanting to actually let the sub breathe... you're basically going to give up your whole trunk for a ported 15, plus you'll lose a ton of sound quality... it'll be loud as hell (if the box is built right) but it'll sound like sh*t in my opinion... it's your cash, do what you will, but just my recommendation: I wouldn't go bigger than a 12, just spend a little extra and get a really nice one...

 

I forgot about Digital Designs... There's a DD 9510, which is a monster of a sub, in the BM right now... https://acurazine.com/forums/car-parts-sale-361/fs-cl-rl-misc-audio-389089/

Also, there's a Rockford 1500 in there:https://acurazine.com/forums/car-parts-sale-361/new-fosgate-amps-705008/

I know you were looking at a 15, but this 10 will move... and it'd probably get damn low as well... check youtube for some vids, and i think you'll see what I mean...