TruPlaya26

Ok heres the situation, my front door speakers are infinity kappa 63.7i 3-ways, rms is 75 watts they peak at 225 watts, my rear deck speakers are MB quart reference rce269 components, rms is 80-150 and peak at 150-200, not sure, lol. i have an alpine stereo receiver that gives rms 18x4 and peak 50x4 watts. so if i put in my amp which is an infinity reference 7541a, rms 111x4 watts, do you think i might blow my speakers? thats a total of approx. 130x4 rms and god knos how much for peak, lol. but i just dont want to blow my speakers, so do you guys think i should put in that amp or maybe get a slightly smaller one?

Jahntassa

That amp is fine for those speakers. This is why there are gain controls on the amplifier. Once everything is in, you need to tune the amplifier to get it working right.

75 watt peak on Kappa components? That seems kinda low to me.. But either way, you should be fine with that combination, just tune the amp properly.

TruPlaya26

nah man my components are the MB Quarts and their rms is 80-150, i think their peak is like 200-250, not sure, the kappas are the 3-ways in the front doors and peak at 225, rms is 75. but someone told me i might blow the speakers with that amp, so i just want to make sure they will be ok before i put the amp, also there is additional wattage going to the speakers from the alpine receiver, about 18x4 watts rms and 50x4 peak.

IntellaWorks

I want to say by reading some of the audio-geeks posts around here that I read somewhere that its harder to blow your speakers by overpowering them as opposed to underpowering them. I think you're going to be all set..

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TruPlaya26

Really? how can you blow them by underpowering them? I have never heard of that before.

Jahntassa

If you underpower them you introduce distortion. Distortion is a much bigger killer of speakers than practically anything else.

By overpowering, you can turn DOWN the amplifier, and you just happen to have power in reserve. As long as you don't turn it up too high, and physically destroy the speaker itself, it will be fine.

TruPlaya26

so if i power them with the factory radio that would be bad for them then right? then i run the risk of blowing them?

Jahntassa

Yup, pretty much. If you don't turn the headunit volume up to the point of distortion, though, then it'll be fine, you just won't be getting anywhere near the clarity or volume you could be getting out of them.

The problem comes when you have an underpowered amplifier that's turned up all the way, and distortion goes through the speakers.

TruPlaya26

o ok, damn i never knew that, lol, and you would know if your speakers are blown cuz there would be a lot of distortion right?

Jahntassa

Usually you'd hear a lot of crackling with the music / sound, or just crackling, a very kind of tinny sound. At least in my experience.

bbfoto

TruPlaya26,

I hope that I am understanding you correctly, so if not, I apologize.

You should NEVER connect the Infinity Amp AND the CD Stereo/Head Unit's speaker outputs to the speakers together!!! If you connect the Infinity Amp to any of the speakers, you should NOT CONNECT the head unit's speaker outputs to any of them at the same time!

Therefor, if you connect Channels 1 & 2 of the Infinity Amp to your Front Kappa Components, and Channels 3 & 4 to the Rear MB Quarts, you should NOT be using the Head Unit's Internal Amplifier AT ALL! You will damage the HU, Amp, and possibly the speakers if they are connected together.

Again, if I misunderstood what you are planning to do, please disregard the above.

The Infinity 4-channel amp will be fine for both the Kappa 3-ways and the MB Quarts. As mentioned previously, you do not want to turn the Gain Control all the way up on the amp.

Here is a guide to setting up the GAINs on your amplifier:

Select a CD that you are familiar with and one that has excellent, clean and clear sound quality.

Start by connecting only One set of speakers to the Infinity Amp at a time (e.g. If you start with the Kappas in front, you should have the Quarts in the rear disconnected. Then when you want to set the gain for the rear Quarts, you should disconnect the Kappa's in front so you aren't straining to hear one set of speakers over the other.) It will be much easier to hear the distortion this way. Distortion will sound like gritty, tinny, or rough/harsh sound, or you will hear the speakers crackle or pop which is dangerous.

The Gain Controls for both the Front (usually channels 1 & 2) and the Rear (usually Channels 3 & 4) on the Infinity Amp should be set at their minimum settings, which is usually all the way Counter-Clockwise or to the let.

Second, set your CD Stereo/Head Unit's Volume knob to about 75%-80% of full or maximum volume. Any higher than that and Most stereos start to send out a distorted signal which is not a good thing.

While you have the Stereo set at that volume, slowly turn up the Gain Setting on the Infinity amp until it starts distorting your speakers, or at the loudest point that you will listen to them, whichever comes first, then quickly back off or reduce the gain setting slightly to ensure you will not have distortion and risk the chance of blowing your speakers. Do all of this while the car is running at an idle so that there is full power going to the amp. Do this independently for both the Kappas in the front (Channels 1 & 2) and the MB Quarts in the Rear (channels 3 & 4.)

Those Kappas and MB Quarts are pretty efficient speakers, meaning they usually don't need that much power to get loud, so you may find that you don't need to turn up the Gains on the Amp much at all. This is a good thing. Setting your gains in this manner will ensure that you can play your system at it's loudest without risk of distortion and damage to the speakers.

The only thing you will have to remember is that you Should NEVER turn your Stereo Volume knob OVER the 75% or 80% mark!

Here is a link to a much more accurate way to set your Amplifier Gains, but you will need a Test Tone CD (you can find these on the Internet to download) and a Digital Multi-Meter/Volt Meter which you can get at Radio Shack or on eBay if you don't already have one:

http://mobile.jlaudio.com/support_pages.php?page_id=143

Browse this site for many more Tutorials under the "Support" section.

Hope this helps.

Jahntassa

Good catch bbfoto. I did miss the post where he stated:

"also there is additional wattage going to the speakers from the alpine receiver,"

If you have the amplifier connected, then you do NOT connect the outputs from the reciever itself.

TruPlaya26

ok, thanks a lot guys this really helps a lot, lol. im going to have all this stuff installed professionally at a shop near my house, but ill try setting the gains myself unless they already do it for me. if anyone else has any opinions please let me know. o and one more thing, im going to be installing the alpine stereo tomorrow and its going to be connected directly to the speakers, they will be running of the internal amp for now. when i go to install the amp, do i need to tell the people at the shop to disconnect the stereo from the speakers? and if i disconnect the stereo and only have them hooked up to the amp, then how do they get sound? does the stereo also get hooked up to the amp so that the speakers will get the sound? im really new at this so i really need some advice, thx in advance for anyone who helps out.

Damon

Just ask the installers to set your gains for you. If they are true professionals they should have an oscilloscope and the proper test CDs to set you up right.

TruPlaya26

ok yea ill ask them, but just in case ill check it myself afterwards, lol.