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View Full Version : New system. Questions about speakers and amp. "Underpowering"



Suggin
12-05-2013, 03:55 PM
Hey guys, I have a few questions about my system. So this is my first time changing out a stock audio system in a car with brand new parts, yes noobie here . The parts I have alrdy ordered are a set of Alpine type R 100 RMS (coaxial)6x8 for the front two speakers. For the back I have Alpine type S which are 75 W RMS(coaxial 6x8). I ordered a Sound Ordnance M-4075 amp which delivers 75 w rms to 4 channels. I also use an alpine cde 141 head unit.

So, im starting to question my choice of purchasing an amp with only 75 W rms, when i will be installing speakers that have a 100 rms rating. I have read that this can cause my amp to clip the tweeters heating them up and eventually blowing them out ("underpowering" them). Is this true even if I don't crank up my amp at all? In other words, if I just keep my amp at the normal settings (gains ect..) then my amp will not be sending any more power than it would be to my alpine type s's; which is why i bought the amp in the first place due to them being 75 W RMS.

Now, could I use 2 channels of the amp for my two rear 75 w rms speakers and then bridge the other 2 channels for higher wattage for my front 100 w rms speakers? I need to research more on bridging, but won't this make the impedance 2 ohms for the front speakers? Not sure how I would go about doing this with parallel and series. Any help here would be appreciated .

Lastly, since i alrdy purchased the amp I will be using it assuming it won't harm my type r's, would the sound really be that much worse when only 25 W under the speaker's RMS? Does anybody have experience with underpowering their speakers by 25 W rms?

I know I have many questions, just trying not to screw up my first audio installation and want to learn as much as possible before I start wiring. Thanks guys!

trumpet
12-05-2013, 04:31 PM
Speaker power ratings are very commonly misunderstood. RMS power ratings on speakers are basically how much heat the speaker can handle continuously. Unless you're abusing the system with the amplifier dialed in completely wrong with the gain set far too high, the speakers you chose will be completely fine on that amplifier. You also have to be careful about the quality of music you listen to, plus you need to have a high pass filter on. Generally that is going to be around 80-100Hz, and it's a feature of your amplifier. The most important concern is how you use the volume knob on the radio. If it sounds bad, turn it down.

Suggin
12-05-2013, 05:00 PM
Ok thanks! Im not one to ride around blaring music i just enjoy pure sounding music, so if im just keeping it around 80 hz then i should be fine. I know these speakers will not be pushed to their full potential, but they will still sound good correct? changing over from 2001 stock toyota tacoma speakers I would think they will be a huge improvement.

trumpet
12-05-2013, 05:26 PM
I know these speakers will not be pushed to their full potential

When you've gone beyond the dinky chip amplifier built into head units, amplifier power has a minor role with speakers going to their full potential. Please, it will be easier if you try to forget about the power ratings.

For the money you have done ok with your selections, but beyond that you also need to install the speakers well, tune the amplifier gain for good sound, and there is even more to be done to get the speakers sounding their best.

Yes, you should hear a big improvement over the factory speakers.

Suggin
12-06-2013, 08:24 PM
Im going to start installing in the next week or so, i have another question about RCA wiring. The wiring kit i bought which has good reviews is this http://www.crutchfield.com/p_142PA10/EFX-10-gauge-Amplifier-Wiring-Kit.html . I know it's not the best out there but it fits my budget and seems to have everything i need besides my speaker wiring. I believe it only comes with one set of RCA cables and I am wondering if I need two sets so I can control the fade and what not ( I may be way completely wrong). Still learning here, but my HU and amp can handle two sets so is it necessary to install two?

Just a re-cap, I am not installing a sub but 4 speakers to each of the 4 channels of my amp.

Dimwit
12-06-2013, 08:36 PM
I personally am not a fan of amp wiring kits. I recommend this site https://www.knukonceptz.com
Take a look and see if you can find the stuff you need to wire up your amp. There are a lot of options and in my experience the wire is great, very easy to work with.

Suggin
12-06-2013, 08:42 PM
Ill check that out and may spend a few more dollars on some different wiring. I am still stumped on if I need 2 sets of RCA cables or not.. if I only installed one instead of two would that only affect me being able to change the balance and fade?

trumpet
12-06-2013, 09:20 PM
I personally am not a fan of amp wiring kits. I recommend this site https://www.knukonceptz.com
Take a look and see if you can find the stuff you need to wire up your amp. There are a lot of options and in my experience the wire is great, very easy to work with.

For someone who doesn't really know what they're doing, piecing together their own amp wiring kit is an unnecessary extra step that might not even save the person any money.

trumpet
12-06-2013, 09:21 PM
Ill check that out and may spend a few more dollars on some different wiring. I am still stumped on if I need 2 sets of RCA cables or not.. if I only installed one instead of two would that only affect me being able to change the balance and fade?

Use one RCA cable per pair of channels.

whitedragon551
12-06-2013, 09:23 PM
No speaker in history has ever blown due to being underpowered. If they are blown from "being underpowered" its due to improper tuning and/or clipping.