convo with crutchfield about hu's builit in amp

[billybrown66 10+ year member]

i've been looking at purchasing a new hu for a while now and seeing that the kenwood XXV-01D is now on sale at crutchfield i'm looking to pull the trigger. the problem i have is that i'm using an raa4200 for my components up front (running passive) and was looking to use the built in amp on the kenwood for my rear speakers. when talking to a crutchfield employee they said...

"The problem is that you will be tempted to turn the system up to match the output of the amplifiers. This might cause the internal amplifier to clip. You will have to use the internal amplifier as the defining output level. ...using the Kenwood internal power may limit how loudly you can play your system, and the solution is adding an amplifier"

i already have two big mb quart amps in my car i dont have room for another amp nor do i want to run one. does anyone foresee a big problem with using the built in amp on the hu for rear speakers while using an external amp for my fronts? also if anyone has used this this kenwood, was there a noticeable difference with the internal amp turned off as opposed to on?

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[MrSector9 10+ year member]

I had done this for a while since my rears are just rear fill....

The logic that they have is not very good. As you turn up the volume to get your rear speakers to match the fronts.. well the front speakers are going to turn up too.. think about that for a second. No matter how fast you turned the dial the rears would not be able to even come close to the volume of a front amped stage since the front is going to increase in volume too.

 

[lilmaniac2 5,000+ posts]

just leave your rears un hooked..... when u go to a concert u dont turn ur back to the music do ya?

thats just what a sq guy on our team told me

 

[squeak9798 5,000+ posts]

No. Just fade to the front, so that the output level to the rears is decreased further. Should keep the internal amplifier from clipping and distorting, while improving your imaging by decreasing the output from the rear speakers.

Another thing you can do is simply set the gains of the amplifiers with the volume set to the highest level possible without distorting the rears. You will not loose any output by doing this.

 

[Vincent9515 10+ year member]

The HU internal amp will usually start to clip at around 75%-90% of the volume range. Set the component amp to max out around this area. The only way the internal amp would define the maximum output level is if you want the front and back speakers to be at the same volume, which is not needed if it's rear fill.

 

[billybrown66 10+ year member]

thanks guys, i thought their responses seemed a bit fishy. squeak, when i asked them about using the fader they said that it would still result in the rear speakers distorting...thanks for clearing all of that up.

awesome.

 

[bri487 5,000+ posts]

just leave your rears un hooked..... when u go to a concert u dont turn ur back to the music do ya?
thats just what a sq guy on our team told me

thats why they have time delay and what not.

 

[FoxPro5 5,000+ posts]

...
"The problem is that you will be tempted to turn the system up to match the output of the amplifiers. This might cause the internal amplifier to clip. You will have to use the internal amplifier as the defining output level. ...using the Kenwood internal power may limit how loudly you can play your system, and the solution is adding an amplifier"

I completely agree with their logic. That is exactly how I ruined my rear fill coaxials back in the day....which is a blessing in disguise because my system sounded better as a result //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[billybrown66 10+ year member]

yeah, im pretty set on having rear speakers though.

 

[cyantist 10+ year member]

Listen to squeak, for he is wise.. Use the deck power for the rears and fade to the front. OR, match the gains on your front amp to the maximum undistorted output from the rears. This is what the Crutchfield dude was trying to say in a roundabout way.. There's no way the internal amp on your deck is going to keep up to an amplified front stage. (And it shouldn't. Rear fill is exactly that, FILL. It's not supposed to be as loud as the fronts anyways.) Again, just go with my first suggestion and fade to the front (with some gain adjustments if necessary to get everything well balanced) and you should be just fine. Good luck...