Selecting a subwoofer for ktp-445u

[swarb]

So I installed a alpine ktp-445u with instructions thanks to some of you here.

It sounds great and now I have the sound bug and need some more bass to go with it.

I need help selecting a sub and wiring for the amp. The amp is low power and only makes 45wx4 or 90wx2 and I have two channels free for 90x1 or 45x2.

1. Can only 1 channel be bridged? edit* manual for amp wants to be bridged front/rear signals so can't run as 3 channel, only 2/4. Maybe I will email but im not going to chance it and try.
2. Sub suggestions? I plan to use the spare tire well or a smaller box. Probably sealed.
3. I am also looking at front door speakers, probably some infinity reference. 6.5's for the doors? suggestions?

[cdrazic93]

1. I think only one channel can be bridged, yes. I was told by my installer when I got my last sound system that bridging a mutli channel amp is bad for the connections. I'm not sure on wires.

2. http://www.alpine-usa.com/product/view/sbr-s8-4 Thats what I found on alpine, seems to suit your needs and then some. Not sure if its too much, but I cant imagine a 8" woofer with a sealed box wouldn't be much different.

assuming thats #3, I had kenwood speakers in my doors, 6'5s all around. The previous speakers were infinities, but they were self installed by the previous owner and no filters were put in so it sounded like crap. http://www.alpine-usa.com/product/view/spe-6000 These look like good door speakers? hah I like alpine stuff, they're bulletproof stuff.

[Koa]

Ayo swarb, go with a true monoblock amp for your sub. Don't try and overload that ktp.. it's just too low for how much road noise and acoustic space battling the sound system in these rigs

I have a JL 500/1 monoblock paired with a 12W6V2 sub.. love it but most here probably don't need/want that type of power so I'd suggest a 250/1 and a 10W3 or W6

[cdrazic93]

Alpine makes a lovely 250w mono amp too.

[Koa]

Originally Posted by cdrazic93

Alpine makes a lovely 250w mono amp too.

Alpine TRs and swxs

not a JL fanboy but re-reading my post lool, sounds like it- I just got the package for a deal on craigslist. Cool asian guy needed to get rid of it for newborn daughter and helps try and fit the original box into the trunk, remarking "its too loud in my truck, idk how you going to stand it in there" hahaha


Woulda gone alpine, Phoenix Gold, or hertz if I started all over again if buying new, JL is a little overpriced rn

[keithr]

Originally Posted by swarb

I need help selecting a sub and wiring for the amp. The amp is low power and only makes 45wx4 or 90wx2 and I have two channels free for 90x1 or 45x2.

I wouldn't bother trying to do that. You're not going to be able to drive a sub all that well with that little power. If you want, bridge it to 90x2 for your front speakers to give you some added headroom on driving where 95% of your music comes from.

Originally Posted by swarb

2. Sub suggestions? I plan to use the spare tire well or a smaller box. Probably sealed.

The JL Audio Stealthbox for our cars is amazing. Sounds awesome, install is very clean. You can get cheaper options, but they won't be nearly as nice on the installation. There are other car-specific options, but I think this is by far the best.

If you go HERE, you can click the button under the search box and put in your email address to get a 20% coupon for your first purchase. That saved me $130 on my Stealthbox.

You can drive it with this amp:

http://www.sonicelectronix.com/item_...NVX-MVPA1.html

Originally Posted by swarb

2. I am also looking at front door speakers, probably some infinity reference. 6.5's for the doors?

6.5 / 6.75 is the correct size for the doors. You'll need some mounting adapters, like these.

Here's a couple suggestions:

http://wwv.crutchfield.com/Responsiv...86211I&g=52000


If you really want to improve the sound quality, you should do some sound deadening treatment in the doors at the very least. Check out www.sounddeadenershowdown.com. Don will hook you up.

[swarb]

I am looking for a easy solution, which is use the amp that is currently installed lol.

The manual on the alpine amp is confusing. It uses one front left wire and one rear left wire to bridge, and the other channel is front right and rear right? I thought it was supposed to be separated by front/rear channels?
I would like to bridge the two extra channels I have, but the alpine manual uses front/rear to bridge for some reason.

Not sure how Dual voice coils work either, if I can just wire the rear channel +/- left and +/- right on each voice coil? Or would the different signals muddy the sound?

Maybe a better solution is to get new front door speakers and drive the fronts 90x2 instead of the 45x2 I currently have? and decide later if I want a sub and get a amp with more power than 90watts?

[keithr]

Originally Posted by cdrazic93

1. I think only one channel can be bridged, yes. I was told by my installer when I got my last sound system that bridging a mutli channel amp is bad for the connections.

Uhhh, what?

[cdrazic93]

Originally Posted by keithr

Uhhh, what?

My memory sucks, in case im wrong (with audio im probably 90% wrong lol) then my bad!

[gramicci101]

Dual voice coil speakers are not so you can wire one voice coil to each channel. They're so you can have flexibility in wiring. A dual 2 ohm sub can be wired at 1 ohm or 4 ohms. It gets interesting when you have multiple DVC subs and some weird series/parallel wiring scheme to get the most out of your amps.

[keithr]

Originally Posted by swarb

I am looking for a easy solution, which is use the amp that is currently installed lol.

The manual on the alpine amp is confusing. It uses one front left wire and one rear left wire to bridge, and the other channel is front right and rear right? I thought it was supposed to be separated by front/rear channels?

Not sure how Dual voice coils work either, if I can just wire the rear channel +/- left and +/- right on each voice coil?

Amps bridge differently. It doesn't look like this one will bridge to 3 channels, only to 2.

With dual voice coils, the idea is to give flexibility. There are numerous ways to wire up a DVC speaker. You could, theoretically, wire one voice coil to each of the rear channels of the amp. However, incorrect wiring can cause equipment damage. The impedance of each voice coil matters -- a lot. You would need to make sure that the signal you're feeding INTO the amp is a filtered sub signal, not a full-range speaker channel because that amp does not appear to have a low pass filter.

You're really not going to get much performance out of trying to use that amp to drive a sub. It would have to be a very low-power sub in the first place, it's not common to find subs that are happy with 45W RMS. That amp is not designed to be used for subwoofers, plain and simple. Square peg, round hole. The NVX amp I suggested is about the size of a thick cell phone. That opens up a lot of options for easy installations.

My $.02 -- for better or worse.

[swarb]

I'm just being cheap/lazy. I am probably going to get some 6.5's and wire them bridged at 90x2 and then figure out the sub from there.

Anyone recommend some 6.5's for under 100?
2ways?
I have the door speakers hpf at 60hz

I would get the mounting brackets listed in this thread.
And probably a small mount of sound deadening for the doors.
Foam speaker cups? those things do anything?

[gramicci101]

Alpine type S, Kicker KS series, JL TR series, there's a lot to choose from.

Check www.onlinecarstereo.com. They usually have last year's lines at decent prices.

[Koa]

Originally Posted by swarb

I'm just being cheap/lazy. I am probably going to get some 6.5's and wire them bridged at 90x2 and then figure out the sub from there.

Anyone recommend some 6.5's for under 100?
2ways?
I have the door speakers hpf at 60hz

I would get the mounting brackets listed in this thread.
And probably a small mount of sound deadening for the doors.
Foam speaker cups? those things do anything?

For sound deadening use Damplifier Pro for deadening and Overkill Pro foam. Nothing else comes close