QuestionQUESTION: I have bought jbl608 components for front and polk db690 for the rear..My car is swift(hatch back type).. yet to buy an head unit.. I want to gain the maximum without an amplifier. So i need your suggestion regarding head unit.. Will alpine 101em(4*18 rms) do the job? You can suggest any head unit which you feel will do justice to my speakers...
ANSWER: Hi,
Sorry about the late response to your question.
The fact is, there's really not a significant difference between the amplifiers built into most modern head units. You're not likely to find a deck with an output power significantly higher than 20 watts per channel RMS. The Alpine head unit you've chosen should do as good a job as any. You've picked speakers with a relatively high sensitivity rating, which means they can deliver a decent output with a limited amount of power.
To help get the most out of your speaker system, you might want to consider applying a stick-on damping material like Dynamat to your door panels and rear deck metal. The purpose of damping material is to prevent the speaker from inducing a vibration in the mounting surface. If the speaker mounting surface starts to resonate, it's like robbing the speaker of power--any energy expended in making the metal vibrate isn't being used to produce sound.
Hope this helps!
Brian
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QUESTION: 1.The head units come with 1 preout,2 preout and so on. Is it possible to add an amplifier to a headunit with 1 preout?..
2.And regarding the damping material, this is the first time iam hearing about this.As you said my doors are vibrating when i tested wit a demo headunit, so i ve to do this for sure. can you explain little more, like how to do it, the cost..
do i have to place this material only near the speaker or wat? some photos will be very helpful.eagerly waiting for ur reply..
thx in advance....
ANSWER: Hi,
You can add an amplifier to a head unit with a single pre-out, but it involves a compromise. The pre-amp outputs are usually designated as rear outputs, front output, or subwoofer outputs. When you see a single pre-out specification, it means there's a single pair (left and right), and will usually be designated as a rear pre-out. If you connect a 4-channel amplifier for the front and rear speakers, but it's sourced from a single rear pre-out, that means you won't be able to use the head unit's fader control. Because all the sound is coming from a "rear" output, there won't be any sound if you adjust the fader all the way to the front.
More expensive head units will add a second pre-out so that they have separate front and rear outputs. This is the minimum necessary if you want to retain the fader control with an external 4-channel amplifier. Finally, some head units add a third output designated as "subwoofer" or "non-fader". This is useful if you're adding a subwoofer amplifier, because it will allow you to adjust the subwoofer volume independently, and ensure that the subwoofer's output won't be affected by the front/rear fader setting.
As for the damping material: the best-known of these is Dynamat, and their web site does a very good job of illustrating and explaining the product. The item you would be using would be the Dynamat Extreme speaker kit:
http://www.dynamat.com/technical_installation_basic_installation.html
The basic product comes with small squares that simply cover the area around the speaker, and would be applied to the surface before mounting the speakers. You can get larger sheets that let you cover the entire door panel or rear deck. This is useful if there are gaps or openings in the mounting surface. Speakers work best if the rear of the speaker is completely isolated from the front, and damping mat can be used to seal any gaps. However, the basic kit should be enough to prevent the speaker vibration from causing a resonance in the mounting surface.
There are other manufacturers that offer similar damping products, such as Second Skin Audio and Fatmat; but Dynamat is the only one I know of that should be available in your area. Your local car audio suppliers may be able to tell you of others.
Hope this helps!
Brian
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QUESTION: hi brian,
I already have jbl 608c and polk db690.. if i buy the head unit alpine 101 em having 1 preout. And later based on the performance of the front component speakers i may add 2 way amplifier for it. and the rear polk will be supported by the head units.I wont have sub woofers in my car..
Is dis setup ok??? Or do i have to go for headunit having 2 preout.
Since im planning to bye the head unit very soon, i need ur suggestion.
u can also suggest head units. I need crispy clear music without noise..
thanks a lot 4 ur kind replies.. awaiting ur reply..
AnswerHi,
You can certainly run your front speakers from an amplifier, and the rear speakers from the head unit. There's nothing wrong with such a setup. Even if you decide to run both speaker pairs from an amplifier, later, you don't really need a deck with a second set of pre-outs; you'd just lose the ability to "fade" from front to rear, and that's something that most people don't use very often in any case.
Unfortunately, I can't really advise you on a head unit, because the models sold in the North American market aren't the same as the ones sold in your area. I'm not familiar with the models sold overseas, so I can't make a recommendation there. However, I think Alpine in general is an excellent brand.
Brian
