Upgrading soundsystem

TBirdDriver

Registered User
Ok, I need a better sounding system.
After doing a search I have decided to do this.

This is what I am going to use:
Alpine CDA-9825 head unit.
Infinity Kappa 5" x 7" speakers for the front and rear.
Power for these speakers will be supplied by the head unit.
8" JL 8WO speaker mounted in the stock sub box. (I'll make it fit).

I will use a connector to hook the head unit up to the stock wiring for the speakers. I will also use a connector to bypass the stock amp for the speakers.

Questions on install:
1).When I bypass the speaker amp, will the stock sub amp now not work?
2.)Will I have to run a wire from one of the pre amps from the head unit to the sub amp?
3.)If I use the stock sub amp, should the speaker be 4 OHM?
4.)If I have to run a wire from one of the pre amps to run the sub amp, I might as well get a better sub amp. What amp will fit in the stock location of the sub amp, should it be a monoamp, how many watts will be adequate, should the amp be 4 OHM or 8 OHM? (I am not looking for the top af the line amp, just one that would be adequate).

I want to connect the components listed above, and utilized the separate bass control that comes with the head unit.
 
system

does any one have experience on this..?? I have heard of best buy kits,,,, but it would be nice to use the facoty amp... can some one thought out a line?
 
not sure if you're going to be able to use the stock sub amp. i have the sinking suspision that you can't. but in any case, that amp doesn't really put out enough power for a modern 8" sub. it'll work, just not well. IMHO

as far as your other plans. . .
alpine - way to go :)
infinity - eh. . . you can do better. i'm quite partial to my eclipse point source intergrated components. a little extra $ but well worth it.

if your going to get a new sub amp, which i recommend, you'll want to match it to the sub. the amp can change the ohm output to fit the sub. if the sub is 4 ohm you should set the amp to 4 ohm. note- you'll get more power from the amp if your powering a 2 ohm sub.
as far as mono vs 2 channel, it doesn't matter, as long as you can bridge the amp.
as far as how many watts are appropriate, that all depends on how many watts the sub is rated for.

this other thread goes into a lot of the same things. <a href="http://www.sccoa.com/forums/showthread.php?t=44993">click me</a>
 
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Wait a minute I just looked at the specs for the 8WO-4 subwoofer.
It is rated at a Max Continuous Power Handling of 75 Watts.
I would need an amp that is capable of providing the recommended continuous (RMS) power range of only 35W to 40W X 1 @ 4 OHM.
The stock amp should be able to handle that shouldn't it?

Also: For people wondering if it will fit in the stock sub box.
Mounting depth is 4.063"
Hole diameter 7"
 
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TBirdDriver said:
Wait a minute I just looked at the specs for the 8WO-4 subwoofer.
It is rated at a Continuous Power Handling of 75 Watts.
I would need an amp that is capable of providing the recommended continuous (RMS) power range of only 35W to 40W X 1 @ 4 OHM.
The stock amp should be able to handle that shouldn't it?

Also: For people wondering if it will fit in the stock sub box.
Mounting depth is 4.063"
Hole diameter 7"


30W is the minimum amount of power it takes to get the woofer moving and producing sound. according to the chart, 70-80w is optimal. and that's continuous power.
but music isn't continuous. the levels go up and down. just because the amp is rated for 80w rms, doesn't mean it's always putting out that much power. and another thing is that the specs on amps are usually rounded up by the manufacturer.
so if you have a 80w rms amp, most of the time it would only be putting out like 50w, or something like that, and underpowering the sub.
my sub is rated for 200w rms. while my amp is rated at 300w rms. it's a perfect match.
one more thing is that if you're pushing your amp to it's max capacity, it'll burn out quicker.
buy a bigger amp. you can always turn down the power from the amp if you're worried about the speaker distorting.
 
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TBirdDriver said:
According to the spec sheet, this speaker does need 75W.
Here's the spec sheet.
http://www.jlaudio.com/subwoofers/pdfs/6_8W0_MAN.pdf

So I guess I do need a new amp.
And I know nothing about amps.
What would you recommend? 150W, 200W?

for that sub? 125w. 150w would be more then enough.
if you've come to the conclusion that you are going to need an amp anyway, are you still thinking of using the stock enclosure? i think you should just rip it all out and start fresh. it'll be a hell of a lot easier then trying to make it fit into that stock box. then you can have more options. i hear that 8" subs have a great sound quality. but it wouldn't be enough for me.
if you want to stay with that size, i recomend a Bazooka Tube with an external amp. Bazooka's are very efficient subs.
***note*** when choosing subs, look at the sensitivity rating. i think it's abreviated as SPL #. <b>it's very important.</b> "The higher the number, the more efficient the speaker and the louder it will play with the same input power." -Crutchfied definition
as far as placement, i ripped out everything and screwed the amp to the back of the larger rear seat section. perfect fit, and makes for easy access if you want to tune it a little on the fly.
 
vivisex666 said:
for that sub? 125w. 150w would be more then enough.
if you've come to the conclusion that you are going to need an amp anyway, are you still thinking of using the stock enclosure? i think you should just rip it all out and start fresh. it'll be a hell of a lot easier then trying to make it fit into that stock box. then you can have more options. i hear that 8" subs have a great sound quality. but it wouldn't be enough for me.
if you want to stay with that size, i recomend a Bazooka Tube with an external amp. Bazooka's are very efficient subs.
***note*** when choosing subs, look at the sensitivity rating. i think it's abreviated as SPL #. <b>it's very important.</b> "The higher the number, the more efficient the speaker and the louder it will play with the same input power." -Crutchfied definition
as far as placement, i ripped out everything and screwed the amp to the back of the larger rear seat section. perfect fit, and makes for easy access if you want to tune it a little on the fly.

The sensitivity/efficiency rating is based on 1 watt at 1 meter. For example, Mirage speakers are 91db efficient. Meaning with 1 watt of power, the speaker's volume will be 91 db if you measure 1 meter away.

Also, power must double to achieve a 3db increase in volume. So a 94db speaker requires half the power to achieve the same volume.

Power DB
1 91
2 94
4 97
8 100 (this starts to be uncomfortable to me at sustained intervals)
16 103
32 106
64 109
128 112
256 115
512 118
1024 121 (rock concerts I think)

So starting with a higher efficiency can greatly reduce power needs at the top end. Not sure how efficient car subs though.

Also, more power = better. Making a weak amp push it's max power can cause clipping of the signal which can kill a speaker. Get extra power so you don't push the amp too hard.
 
I would definately replace the stock amp. Compare the output of the stock amp to it's size with another amp from Rockford Fosgate, Alpine, Pheonix Gold, etc. of the same output and it's size. Without getting into all the technical information behind all of this, the latter amplifiers are way bigger. Which provide much better quality/cleaner sound. I have one 3 channel amplifier from Xtant powering 10 total speakers. 8 of those speakers are mid/tweeter separates from Diamond Audio and the other two are JLW6's (10's) mounted where the shelf used to be. I remember when I owned two Rockford Fosgate Punch 45 amplifiers. The output was supposed to be 22.5 watts per channel continuous (RMS). I (stupidly) bought another amplifier (Jenson) I believe that claimed it was 25 watts (RMS) x 4 channels. The whole system sounded better off of the Rockford amps vs one Rockford and one Jensen. The Jensen amp just happened to be the same size as the Rockford (pretty close). If I were you, I would seek the help of someone that you feel pretty good with at a local high end car stereo place. Have them recommend components (of course they will be the ones that they sell) and find out the stats on them. Then do a little research about them and their competitor's components. Wait for sales and buy each part when money allows and put them to the side and wait to have them installed all at the same time. And don't forget the alarm! It won't stop theives, but it sure will deter them! Try to go for a stealthy install too. I have installed myself over the years and have owned many components, and after doing what I told you, I have been the happiest with this. Good luck.
 
Well I got the Head Unit put in. All 4 front speakers are working great running off the head unit, however as I suspected, after bypassing the amp, the stock subwoofer does not work.
Is there a way to get the stock amp and subwoofer to work until I get a new amp and sub?
 
there are 3 wires running into the stock sub amp. 1 is the turn on, the other 2 are the signal. to find out what is what, grab a multimeter, unplug the bypass harness and plug back up the factory amp, then splice open the gray casing of the cable going into the sub amp splice each wire back, and probe em to find which is the 4.5-12v turn on for the sub. Once you do this, get an rca y adapter, 1m2f, and cut off the male end, then wire what is left of the rca's onto the other 2 wires from the gray cable. be shure to cut the gray cable in half before the factory 4 channel amp, so there will be no backfeeding. After this has been done, run a set of rca's from the sub out on the radio into the newly spliced y adapter, and you've got a working sub.
 
Thanks a million pearl95sc!
It sounds pretty easy.
Questions:
I understand by your explanation how to splice the y cable up to the woofer. (And hook them up to the back of the head unit)
I will now know which wire is the 4.5 12V turn on and I will also know which ones are for signal.
You say to cut the grey cable in half before the factory 4 channel amp. In doing so, would I not cut through the 4.5 12V turn on? Should I not just cut through the two signal wires, and leave the 4.5 12V alone so that the sub can turn on? (I still want to have the 4 channel bypassed but be able to use the stock sub).
Also: Do I reinstall the bypass?
(I would think that I would have to splice the 4.5 12V to one of the wire in the bypass harness.)
Here's someones picture of the (3)wire harness that goes from the 4 channel amp to the sub amp. (On the left)
 

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Lets simplify this:
As I understand it, in the JBL system, when you turn on the radio it sends a signal to the 4 channel amp to turn on. When the 4 channel amp turns on, it then sends a 4.5V signal to the sub amp to turn on.
Because I have bypassed the 4 channel, it can no longer send a signal to the sub amp to turn on.

Couldn't I just get a 12V to 4.5V converter and wire it up to a spot on the fuse block that supplies power only when the key is on? That way, as soon as I start the car, it sends 4.5V to the sub amp and the amp turns on?

(I would still be bypassing the 4 channel and I would still need to connect the sub with the y connector, but the sub would now be powered.)
 
owww, my brain hurts.

is it going to be a long time before you can get a new sub and amp? you may just want to wait and forgo this nightmare waiting to happen.
just my 2cents.
 
I'm going on a 7 hour road trip next week and I would like to have some bottom end in my car for the ride. Anything is better than nothing. Once I come back I'll have time to install a good amp and speakers.

It's not a "nightmare waiting to happen".
It's actually simple. The amp works just like any other amp except it needs a little different signal to turn on.
I may just take the amp apart, hotwire it so it's always on, and mount a big Frankenstein switch between the amp and the battery to manually turn it on and off.
I can hardly wait to hear the pop when I throw the switch :D
 
TBirdDriver said:
I'm going on a 7 hour road trip next week and I would like to have some bottom end in my car for the ride. Anything is better than nothing. Once I come back I'll have time to install a good amp and speakers.

It's not a "nightmare waiting to happen".
It's actually simple. The amp works just like any other amp except it needs a little different signal to turn on.
I may just take the amp apart, hotwire it so it's always on, and mount a big Frankenstein switch between the amp and the battery to manually turn it on and off.
I can hardly wait to hear the pop when I throw the switch :D


LOL thats too funny. go for it dude. just make sure to have the volume turned down before you throw that switch.
 
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