I really need some help with my system I'm new

[mizar]

Hi!

Well at finally I have installed my sound:

Kenwood Z828 HU
Kenwood KAC-728S 100 Watts X 2 at 4 Ohms
Kenwood KAC-749S 40 Watts X 4 at 4 Ohms
Kenwood KGC-4042A EQ


1 pair of Polk EX369 6X9 100 watts RMS (continous) 300 Peak
1 Pair of Polk GXR69 6X9 70 watts RMS (continous) 175 Peak
1 Pair of Polk EX3500 1 inch tweeter 60 watts RMS (continous) 160 Peak
1 Pair of Polk GXR12 12 inch Subs 165 watts RMS (continous) 365 Peak


All that installed in a Dodge stratus 2002 SE



I have the 4 channel amp at high filter. front and rear. I Have the tweeters and the GXR69 in front. And the EX369 alone in the back of the car. And the 2 channel amp with the 2 subs.


In the Manual of the amps says in the speaker slection:

The rated input power of the speakers that are going to be connected should be greater than the maximun output power (in watts) of the amplifier.


What is the rated input power? the peak power or the continous?
What is the maximun power of the amps?
the 40 x 4 at 4 ohms or what?

I'm not sure if my system will handle well the power of the 2 amps. Or I'll crash the speakers or subs. If my system can handle it. Also need to know If I can put at max power the 2 amps? and the speakers will be fine.


maybe those are kind of stupid questions. But I'm not a pro.

I really apreciate the help! Thanks :D

[Kim]

Mizar,
The continuous power rating for the speakers is the smaller of the two power ratings which is what the speaker can handle without damage. The peak power rating is the maximum amout of power that the speaker can handle for a short term time period.
More damage is done to speakers by playing them at louder listening levels when driven by smaller power amplifiers. If you hear a "hard" or "steely" sounding midrange and high frequencies, then the amp is being driven into clipping. When this occurs turn it down. Then you will not be over driving the system and risking damage to the amplifiers or speakers.
Set the low pass and high pass crossover frequecies at 80 Hertz.
Because Kenwood uses a 12 db per octave crossover slope in the active crossover, you may have to invert the polarity ( the positive and negative wires coming from the amplifier ) on the woofer to get the best bass response.
Regarding the amplifier output power... you might want to check some of the older car audio magazines to see if you can find a review of these models.

Thanks,
Kim

[DAlba]

Kim, can you elaborate more on why you should reverse polarity b/c of x-over slope?

[Kim]

First and third order slopes are phase correct. Second and fourth order slopes invert phase.

[mizar]

Hi thanks 4 the answer. I have put eh xovers of the 4 channel amp at 80 as u told me.

But I have some more questions.

Acording to the manual of the polk 6x9. It says that If u r using subs. U may want to cancel the bass on the speakers by using a bass bloker or a specific capacitor. It says that by doing that u'll have a better mid-range detail and an increased power handling.
Or if u have an electronic x over. by setting it below the 100 Hz or so.



The main point here is that I don't want to crash the speakers and that I want to use them with the most power I can do so.
If I put all the power of the 4 channel amp at max. The speakers will be OK?


And that polarity thing Is not very clear. I Just have to change the cables that are goint out of the amp and to the subs?

Thanks

[Kim]

I would not recommend setting the gain to the maximum position.
If you do this then you will not have much control over the volume settings. It will get very loud at a much lower setting. You have to remember that the amplifier is only capable of producing a fixed amount of power. Increasing the gain does not give you any more power, it just causes you to use it up prematurely and if driven too hard clipping and distortion occurs which then can cause the speakers to fail.
Since these amplifiers have built in crossovers for the high pass and low pass frequencies, there is no need to install a high pass passive filter or " bass blocker" .
By using the active filters in the amplifier the speakers will blend better with the subs and the front and rear speaker 4 channel amplifier will not have to work as hard because it does not have to reproduce low bass frequencies. The amplifier will run cooler and the voltage and current demand from the charging system is greatly reduced.
Regarding the phase of the subs... if you notice the bass response is sounding weak or thin , then reverse the speaker wires that are connecting the sub to the amplifier.
This will get the subs acoustically in phase with the rest of the system and produce better and stronger bass. Hope this helps.

Kim