a little in depth explaination please.

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=54966
Printed Date: May 14, 2025 at 4:56 AM

Topic: a little in depth explaination please.

Posted By: mi_what
Subject: a little in depth explaination please.
Date Posted: May 02, 2005 at 9:34 AM

I am new to sub systems in car audio, so I figured I would look like an ass and ask these questions before I mess something up.
1. What exactly are the gains for, and what is thier potential? Why is it bad for them to be at 90-95%?
2. Can somebody please explain what "channels" are on an amp and what they are used for?
3. What kind of amps are ideal for components and what kind are ideal for subwoofers?
4. What is a passive crossover and how do they help?

I appreciate any help, I just want to know so I know what to look for when picking out a system.

Replies:

Posted By: stevdart
Date Posted: May 02, 2005 at 9:51 AM

1. A gain is a level-setting device. It matches an amplifiers output to the voltage of the input. Read through this forum SEARCH on the subject of setting gains. There is no such thing as percentage in determining gain setting. You are assuming that full to the right is okay to do when you use a percentage to describe where you turned the screw. Depending on the voltage inputted from the head unit, the amp's gain screw may be set anywhere along it's rotation. Normally, the gain will be properly set more towards the beginning of the rotation...or more to the left side. Here is a good in-depth explanation of gains - www.bcae1.com

2. A two-channel amp was devised to produce stereo sound. It consists of two amplifiers, one labelled "left channel" and the other labelled "right channel". The two mono amps (channels) are packaged into one unit and is called an amplifier, or a 2-channel amp. Each channel is fed a signal, one being left stereo, the other being right stereo, and the amplifier amplifies those signals, then outputs to the speakers.

3. Two channel amps are ideal for components because of the need for stereo sound. It will provide power for a set of components or two individual components. A four channel amp consists of 2 two-channel amps combined and will provide for either two sets of components or four individual components. Mono (one channel) amps are ideal for the mono output of subwoofers.

4. Passive crossovers consist of a combination of inductors, capacitors and resistors....chosen and wired together in such a way as to provide limits to the frequency range or relative decibel level any individual speaker is allowed to play.

Crossovers in your home audio speakers may look something like these:

posted_image

The tweeter and midrange of a component set are separated by a crossover. More info here: https://www.the12volt.com/caraudio/cross.asp

In fact, take some time to read through all the help listed in the left column of this page, as well as bookmarking the link I showed you for many days and nights of reading and education. The search results for gain setting should adequately answer your questions in that regard.

Cheers!

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: mi_what
Date Posted: May 02, 2005 at 10:42 AM

Your input has brightened my day. You were extremely helpful. Thanks posted_image

Posted By: Paradigm
Date Posted: May 03, 2005 at 9:24 AM

stevdart wrote:

2. A two-channel amp was devised to produce stereo sound. It consists of two amplifiers, one labelled "left channel" and the other labelled "right channel". The two mono amps (channels) are packaged into one unit and is called an amplifier, or a 2-channel amp. Each channel is fed a signal, one being left stereo, the other being right stereo, and the amplifier amplifies those signals, then outputs to the speakers.

Shouldn't this be "mono?" It's not stereo until the two channels are used in tandem. Might be some confusion there...

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VEHICLE: 2002 GMC Sonoma ZR2
Alpine CDA-7940
AudioControl EQT x2
JL Audio 1000/1
JL Audio 10W6 (originals) x3
Kicker ZR120
Kicker ZR460
Polk GXR-6 x4
Polk GXR-4 x2

Posted By: haemphyst
Date Posted: May 03, 2005 at 10:27 AM

Actually, unless the individual amplifier channels SHARE the power supply, it is technically a dual mono amplifier, which CAN be used for amplifying stereo signals. Stereo means nothing, except that the signal being amplified has stereophonic information contained. Dictionary.com defined stereo as this:

stereo

adj : designating sound transmission from two sources through two channels [syn: stereophonic, two-channel] n 1: reproducer in which two microphones feed two or more loudspeakers to give a three-dimensional effect to the sound [syn: stereo system, stereophonic system] 2: two photographs taken from slightly different angles that appear three-dimensional when viewed together [syn: stereoscopic picture, stereoscopic photograph]

So you see, stereo does NOT mean, exclusively, "two channels in one chassis". Stereo actually refers to the SIGNAL being amplified. There's MY two cents... Sorry, as you can see, if you ask me the time, I'll teach you how to build a clock...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Posted By: Paradigm
Date Posted: May 03, 2005 at 11:20 AM

What time is it? posted_image

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VEHICLE: 2002 GMC Sonoma ZR2
Alpine CDA-7940
AudioControl EQT x2
JL Audio 1000/1
JL Audio 10W6 (originals) x3
Kicker ZR120
Kicker ZR460
Polk GXR-6 x4
Polk GXR-4 x2