Need Help - Don’t Understand Ohms

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=18834
Printed Date: May 18, 2024 at 4:19 AM

Topic: Need Help - Don’t Understand Ohms

Posted By: CyberSlip
Subject: Need Help - Don’t Understand Ohms
Date Posted: September 12, 2003 at 1:37 PM

I knew I should've paid more attention in math class!! The more I research my problem, the more confused I seem to become. I recently traded in my 10s and installed a pair of 12" Kicker Solo-Baric L5s, both 2 Ohm, Dual Voice Coils. The amp that I have is an Alpine MRD-M500 (which was previously pushing 2 tens). The owner's manual for the amp lists speaker impedance at 4 or 2 Ohms. Anyway, since this amp is only 500 Watts, and each Solo-Baric will handle 600 Watts, I wanted to add a second MRD-M500, and have one amp pushing each woofer. The guys at the local radio shop said I cannot do this because of the Ohms. I'm not sure if they're wired in series or parallel (they were already in an enclosure when I bought them). I would much rather spend $300 on a second M500, but they're telling me I would need to upgrade to the much more expensive M1000. This Ohm stuff is really confusing me. Can anyone shed some light on this to help me better understand it? Thank you so much.

Replies:

Posted By: DYohn
Date Posted: September 12, 2003 at 2:37 PM

Ohms are a measure of resistance to current flow. The lower the total resistance the higher the current flow. Amps are rated for the maximum safe amount of current they can deliver.

Your amp is a 2-ohm amp, which means it will safely deliver power into any load 2 ohms or greater.

Your subs (assuming they are model S12L52) have two voice coils, each with 2 ohms resistance. If you wire them in series, this adds the two resistances giving a 4 ohm load. If you wire them in parallel, it cuts the resistance in half, giving 1 ohm.

Your Alpine amp could be used to power both speakers if wired this way:

posted_image

This will give the amp a safe 2-ohm load, and deliver about 400 watts at 12V (500 watts at 14.4 volts) so your really do not need another amp, nor do you need the more expensive one... unless this is not enough power for your tastes.

Posted By: CyberSlip
Date Posted: September 12, 2003 at 3:16 PM

Thank You.......that's the easiest to understand explanation I've seen yet. It is pushing both of them now (and doing a pretty good job of it)......I just have the Tim Taylor Syndrome......More Power!!! I'm looking through some tech pages for the amp now to see if I can make any fine tuning adjustments. Back in the day, we didn't have all this Hi-Tech stuff.......we just bought it and hooked it up. Sure has gotten confusing over the years......thanks again for the help. Oh, can anyone tell me how to get and sustain 14.4 Volts to the amp?

Posted By: flatulatta
Date Posted: September 12, 2003 at 7:50 PM

i think u have to get eiter a better alternator or a differnet kind of battery not sure exactally which 1