Confused about car audio
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=78224
Printed Date: April 29, 2024 at 2:41 AM
Topic: Confused about car audio
Posted By: allthotslost
Subject: Confused about car audio
Date Posted: May 23, 2006 at 11:37 PM
I am new to this and trying to learn the best I can but i have a few questions: 1. How can you bridge a mono amp? 2. If you wire 2 subs parallel, does it cut the output in half? (I dont think it does) 3. If you have 2 single 4 ohm subs, and a 2 channel 4 ohm amp, can you put 1 channel to each sub? This is all the questions i can think of now. Thanks for any help.
Replies:
Posted By: aznboi3644
Date Posted: May 23, 2006 at 11:43 PM
1. You cannot bridge a mono amp because there are not multiple channels to bridge. A mono amp is what it is...MONO meaning ONE.
2. Wireing 2 subs in parallel does not cut output in half. It only cuts the impedance in half.
3. Yes. Easiest and simplist way to wire 2 4 ohm subs to a 2 channel 4 ohm amp would be each sub to a channel. You could wire the subs in series and bridge the amp but it will be the same output if wired to each channel.
Glad to help.
Posted By: mustangfoo
Date Posted: May 23, 2006 at 11:44 PM
1. You cannot bridge a mono amp, remember in school, mono is one, bi is two, tri is three, well in our case mono is one and stereo can be two or more. 2.It depends on the ohms your are working with, if you are working with (2) 4 ohm speakers than the ohms halve, if you are working with a 4 ohm and an 8 ohm speaker, then they don't halve, they equal themselves out to 6. 3. Yes you could, but that doesn't mean you are going to get the most out of your amp, you should read the HOW TO CHOOSE AN AMPLIFIER thread. Read things on this site, read things posted in the forums, just read and then after that read, and when you are done with that read some more, trust me you will learn a whole lot just by reading the things on this site.
Posted By: allthotslost
Date Posted: May 24, 2006 at 8:54 AM
mustangfoo wrote:
1. You cannot bridge a mono amp, remember in school, mono is one, bi is two, tri is three, well in our case mono is one and stereo can be two or more.
I was about 99% sure of this, but this following "specification" off cardomain screwed me up: RMS Power @ 4 Ohms: 300W x 1 @ 4 ohms THD at 4-Ohm RMS Power: <1 % Bridged RMS Power @ 4 Ohms: 600W x 1 @ 2 ohms And also: 4.If an amp is 2 ohm stable and the RMS values are say "600W @ 4 ohms" is it the same output at 2 ohms? 5. If you are making a sealed enclosure and your subs need 2 cu ft, and you are putting two subs in one box, would you make a 4 cu ft or a 2 cu ft box. (Im almost positive it is just a 2) sorry for all the questions, these are just things I couldnt find on my own.
Posted By: bassplayer24_7
Date Posted: May 24, 2006 at 9:44 AM
you would make the enclosure 4 cu ft if both subs are in one chamber, if they are in separate chambers each chamber will be 2 cu ft.
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Phoenix Gold Octane R 2.0:1
Phoenix Gold Octane R 5.0:4
Clarion Crossover
JVC Head Unit
Posted By: stevdart
Date Posted: May 24, 2006 at 10:31 AM
4. There is more output at the lower (2 ohm) impedance load. Basic Ohm's Law: voltage = current X resistance, and power = current X voltage. A specific variation on these base formulae, as an answer to your question, is this one: P = E^2/R, or Power = Voltage squared divided by impedance. Keep in mind that output is rated per channel. A mono amp is one channel, a two-channel amp is rated per each channel. Bridging a two-channel amp is splitting the impedance load across both channels. That's why you'll see ratings for bridged output equal to the two channels at half the impedance each. BTW, if those specs you listed were referring to a mono amp, it is an error to use the term "bridged". Instead, they could have correctly said, "Using both sets of amplifier output terminals into 4 ohms". The reason is that this amp has dual terminal sets for convenience, which you may use or not. Using both of them parallels the connecting wires so that a 4 ohm load becomes 2 ohm. In most cases, the wiring is done on the subs themselves instead, and only one set of terminals is used. 
(BCAE1.com) ------------- 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: haemphyst
Date Posted: May 24, 2006 at 11:19 AM
mustangfoo wrote:
2.It depends on the ohms your are working with, if you are working with (2) 4 ohm speakers than the ohms halve, if you are working with a 4 ohm and an 8 ohm speaker, then they don't halve, they equal themselves out to 6.
ANY time you parallel resistances, the NET resistance (or in this case, impedance) will ALWAYS be lower than the lowest individual resistance, in your example 4 ohms. They don't "average", as your math suggests... Actually an 8 ohm load in parallel with a 4 ohm load will yield a net 3 ohm load, not 6 ohms. ------------- 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: allthotslost
Date Posted: May 24, 2006 at 12:11 PM
So if i have an amp that is stable at "1 ohm stereo 2 ohm mono" does this mean that if i bridge the connections (mono) it can handle 2 ohms, but if i use the channels seperately, they are 1 ohm stable? and if i have an amp that is 2 ohm stable, and the output is 600w, how much is the output at 2 ohms? stupid question: If the amp is 2 ohm stable is that no matter what? thanks guys so much for the help, i know these sound like dumb questions to you.
Posted By: DYohn
Date Posted: May 24, 2006 at 1:00 PM
allthotslost wrote:
So if i have an amp that is stable at "1 ohm stereo 2 ohm mono" does this mean that if i bridge the connections (mono) it can handle 2 ohms, but if i use the channels seperately, they are 1 ohm stable?
Yes allthotslost wrote:
and if i have an amp that is 2 ohm stable, and the output is 600w, how much is the output at 2 ohms? stupid question: If the amp is 2 ohm stable is that no matter what?
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Posted By: saturnsubohio
Date Posted: May 24, 2006 at 1:23 PM
allthotslost wrote:
So if i have an amp that is stable at "1 ohm stereo 2 ohm mono" does this mean that if i bridge the connections (mono) it can handle 2 ohms, but if i use the channels seperately, they are 1 ohm stable?
and if i have an amp that is 2 ohm stable, and the output is 600w, how much is the output at 2 ohms?
stupid question: If the amp is 2 ohm stable is that no matter what?
thanks guys so much for the help, i know these sound like dumb questions to you.
to take shakespeare into car audio.
a Rose is a Rose is a Rose
well 2 ohms is 2 ohms is 2ohms.
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Electrical Engineer
Ohio University Alumni
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