HELP! with amplifier one easy quik question

[FSTRDNU]

i have this amplifier

http://hififorless.com/showProduct.php?productid=57572&PHPSESSID=f1cfd2145cdc73e4dbb3b24787d23959

it says if it runs at 2 ohms instead of 4, it mkaes more power 125x2, instead of 100x2

how do i switch this
thnaks

 

[fwd-turd]

the ohm load is determined by you speakers (subwoofers) if you have two 4 ohm single voice coil subs it can easily be wired to 2 ohm
pos neg pos neg
+ - -------- + -
| |
| |
| |
to positive to neg
on amp on amp
then take this pos and then take this neg
hook to positive on left and hook to neg on
channel right channel

and this will be bridged
beacuse if you have two 4 ohm speakers you cant
make them 2 ohm on one channel each

you shouldnt post this here though it should be in the
section for audio and apperance it should be around 240 rms bridged
like that the forum slides everthing over so take the middle one neg and one pos hook them together then from the outsides one pos goes to pos on the left channel and the neg one the right channel

 

[FSTRDNU]

thnaks for the reply, i really appreciate it, but can someone tell me what i ahev to do, i am running it to 2 6x9's, but from the way they sound, it sounds liek they need more power, what to do?

 

[leet]

Moved to correct forum.

 

[styx]

no point in moving it then most people can't answer, the only way to lower your impedance with the stuff you have is hook the speakers up in parrallal (not recommended but many people do it), which means you lose left and right (can only run one channel bridged), but gain more power, depending on the amp you will probably have to bridge it in order to split the load amongest each channel for positive and negative parts of the cycle, with respect to where you would measure the zero reference, depending on the amp you have, it could have 2 rails or it could just be a single supply with the audio filtered by cap to eliminate the dc, and many other ways. look at your instructions cuz i am lazy like you and don't want to

 

[DGajre777]

no point in moving it then most people can't answer, the only way to lower your impedance with the stuff you have is hook the speakers up in parrallal (not recommended but many people do it), which means you lose left and right (can only run one channel bridged), but gain more power, depending on the amp you will probably have to bridge it in order to split the load amongest each channel for positive and negative parts of the cycle, with respect to where you would measure the zero reference, depending on the amp you have, it could have 2 rails or it could just be a single supply with the audio filtered by cap to eliminate the dc, and many other ways. look at your instructions cuz i am lazy like you and don't want to

WHY is running in parallel is not recommended? WTF You run a brigded channel to reduce the impedence on the amplifier which puts out more output. HOW do you lose your left and right? You don't lose it, you still have it, you just don't use it.

The only thing is that by running a 2 ohm load instead of a 4 ohm load on full range speakers you get a slight increase in distortion depending on the specs of the amplifier.

The point of having a thread is so that people can answer it, that's why it needs to be in the right forum. I don't want to see a audio thread in a tuning section now, do I?!

FSTRDNU - There is no 2 ohm or 4 ohm switch on the amplifier, it is how you wire it. You can wire it bridged in a 2ohm load like this...

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[styx]

WHY is running in parallel is not recommended? WTF You run a brigded channel to reduce the impedence on the amplifier which puts out more output. HOW do you lose your left and right? You don't lose it, you still have it, you just don't use it.

The only thing is that by running a 2 ohm load instead of a 4 ohm load on full range speakers you get a slight increase in distortion depending on the specs of the amplifier.

The point of having a thread is so that people can answer it, that's why it needs to be in the right forum. I don't want to see a audio thread in a tuning section now, do I?!

FSTRDNU - There is no 2 ohm or 4 ohm switch on the amplifier, it is how you wire it.

ok lets say you have a class ab amp becuase there is no such thing as a class b by itself, for those who know how to design audio amps you need to have the brain to go with pinky (its a process control that has a smaller faster more accurate amp tell much more power amps that draw all the juice (wich are dumber and slower) put the power out). when you bridge you divided the load amongest the mosfets of both channels. so its a 50-50 split of power dissipation on the channels of the amp to drive one load thats why you move one wire to the other channel typically but that depends on the design of the amp

there is much more of a science about not hooking up in parrallal and signal lose is one of them, but there can be power issues, don't remember what it was cuz i hate audio stuff but know to much about it

 

[styx]

ok lets say you have a class ab amp becuase there is no such thing as a class b by itself, for those who know how to design audio amps you need to have the brain to go with pinky (its a process control that has a smaller faster more accurate amp tell much more power amps that draw all the juice (wich are dumber and slower) put the power out). when you bridge you divided the load amongest the mosfets of both channels. so its a 50-50 split of power dissipation on the channels of the amp to drive one load thats why you move one wire to the other channel typically but that depends on the design of the amp

there is much more of a science about not hooking up in parrallal and signal lose is one of them, but there can be power issues, don't remember what it was cuz i hate audio stuff but know to much about it

point me to the audio forum here

 

[styx]

now your pic comes up don't you see that you are running both speakers from the same source assuming where it says 2ohms is the source so 2 speakers are running from one channel when you bridge that is what you are doing, turning a dual channel amp into one channel at a higher power becuase you are splitting the power dissipation on the mosfets

 

[styx]

and if you work the equations out with home audio you typically multiply your power by a factor of 4 (with bridging). but then again it all depends on the design of the amp

 

[DGajre777]

when you bridge you divided the load amongest the mosfets of both channels. so its a 50-50 split of power dissipation on the channels of the amp to drive one load thats why you move one wire to the other channel typically but that depends on the design of the amp

there is much more of a science about not hooking up in parrallal and signal lose is one of them, but there can be power issues, don't remember what it was cuz i hate audio stuff but know to much about it

Since you said hooking up in parallel is not recommended, can you explain what power issues there are with hooking in parallel? and it's parallel not 'parrallal'

 

[DGajre777]

now your pic comes up don't you see that you are running both speakers from the same source assuming where it says 2ohms is the source so 2 speakers are running from one channel when you bridge that is what you are doing, turning a dual channel amp into one channel at a higher power becuase you are splitting the power dissipation on the mosfets

And that how you can decrease impedance and bridge an amp!

 

[DGajre777]

point me to the audio forum here

Audio goes in the interior of the car, so that would be the Appearance/Interior/Exterior forum.

 

[styx]

Since you said hooking up in parallel is not recommended, can you explain what power issues there are with hooking in parallel? and it's parallel not 'parrallal'

thanks for the spelling suggestion but i am not looking for website on it again for the effect on the speakers, but it cause the amps power supply to heat up much more. when ever you drop your impedance you loose audio quality. since the speakers were ment to dissipate such and such power at the 4ohms they were designed to be driven at, in terms of heat dissipation, dropping the resistance by half drives the current up by 2. this is where you will see the more expensive amps start to stand out. because they won't hit thermal shutdown as early or never will. i never had to design speakers but the buys who did can tell plenty on why not to, people who just hook the stuff say yep it works people who really get down in speakers will be able to tell you why not to (this is where they cheap stuff gets weeded out from the good stuff)

also if you crack open an amp and look at the characteristics of the op-amps used you will see on the data sheet how the frequency roll of will change for response, and thd will sky rocket

 

[styx]

as for effect on speakers aside from worse sound talk to a guy who has designed speaker look around on the web there is plenty of webpages arguing this topic. parrallel or not to parrallel, i am a fan of not to, becuase of my decision when i actually cared about this stuff and researched it

 

[DGajre777]

thanks for the spelling suggestion but i am not looking for website on it again for the effect on the speakers, but it cause the amps power supply to heat up much more. when ever you drop your impedance you loose audio quality. since the speakers were ment to dissipate such and such power at the 4ohms they were designed to be driven at, in terms of heat dissipation, dropping the resistance by half drives the current up by 2. this is where you will see the more expensive amps start to stand out. because they won't hit thermal shutdown as early or never will. i never had to design speakers but the buys who did can tell plenty on why not to, people who just hook the stuff say yep it works people who really get down in speakers will be able to tell you why not to (this is where they cheap stuff gets weeded out from the good stuff)

also if you crack open an amp and look at the characteristics of the op-amps used you will see on the data sheet how the frequency roll of will change for response, and thd will sky rocket

Good point! BUT if you buy an amplifier that is designed to put out lets say 300 x 2 @ 4 ohms, 500 x 2 @ 2 ohms and 900 x 1 @ 1 ohm it won't heat the amplifier and cause thermal overload. If you buy a cheap amp that is only designed to run at 4 ohms and hook it up at 2 ohms, yeah you'll heat it up and if it doesn't have overload and thermal protection probably burn it up.

The distortion increases under a 2 ohm load compared to a 4 ohm load but when you are running subwoofers the 1% increase in THD is not really noticible unless you are a SQ guy. People who hook up amps and subs in parallel do it to get more power output for SPL, not SQ.

 

[styx]

Good point! BUT if you buy an amplifier that is designed to put out lets say 300 x 2 @ 4 ohms, 500 x 2 @ 2 ohms and 900 x 1 @ 1 ohm it won't heat the amplifier and cause thermal overload. If you buy a cheap amp that is only designed to run at 4 ohms and hook it up at 2 ohms, yeah you'll heat it up and if it doesn't have overload and thermal protection probably burn it up.

The distortion increases under a 2 ohm load compared to a 4 ohm load but when you are running subwoofers the 1% increase in THD is not really noticible unless you are a SQ guy. People who hook up amps and subs in parallel do it to get more power output for SPL, not SQ.

exactly why i hate car audio its all about dbspl, and not signal to noise ratio, damnit i love my classical music and the sounds of the instruments. but the distortion will increase more than that, and it depends on the dampening of the filter used to get out the high, there is so much to take into consideration. but more current through the same boost regulator will definitely produce way more heat becuase of the fixed values of the physical components used

more current same resistances means more heat when looking at the amp

 

[DGajre777]

I'm a SPL guy, so if a little distortion gives me more power, so be it

On my 92 eclipse I had 1 Rockford Fosgate 12" dual voice coil speaker in a sealed box hooked up to 2 bridged amps for each voice coil. That thing was loud! Did I get more distortion? yeah, but the windows vibrating made more noise that the distortion.

 

[styx]

I'm a SPL guy, so if a little distortion gives me more power, so be it

On my 92 eclipse I had 1 Rockford Fosgate 12" dual voice coil speaker in a sealed box hooked up to 2 bridged amps for each voice coil. That thing was loud! Did I get more distortion? yeah, but the windows vibrating made more noise that the distortion.

at that point your not even listening to music, you are just feeling your internals vibrate against each other.

now if they were each 2 channel amps and you had it wired right, you would be dissipatting the heat across 4 channels using 2 amps. each channel uses its own mosfets. so yes you will produce a ton of bass as you youngins put it

also class ab amps are very very inefficient and are supposed to get very hot thats why people say they are not effiecient most of the power gets dissipated as heat and doesn't get to your subs.

 

[styx]

i also want to make a proposal that we boycott 1st order audio filters thats 6db/decade, show those audio companies we are not stupid by being over charged for filters

if your filter uses a cap the equation is f-3db= 1/(2pi(F)(L))

1/((2(pi)(F)(C))=f-3db if remember those days right, well the secret is out thats all there is to it, next is how high qaulity of an inductor or cap do you want. more advanced filters have to deal with poles and then the calculus looks really cool if you produce a 3d plot in matlab

 

[styx]

DGajre777

nice talking with you, you are pretty knowledgeable with car audio, but i have to pack for the damn Indy race in Nashville, because i have testing to do with the cars, some one want to trade shit jobs traveling sucks.

 

[DGajre777]

DGajre777

nice talking with you, you are pretty knowledgeable with car audio, but i have to pack for the damn Indy race in Nashville, because i have testing to do with the cars, some one want to trade shit jobs traveling sucks.

Have fun

 

[FSTRDNU]

link to my amp is on 1st post
it is actually a 2 channel amp
i am running 4 speakers of of it
2 6x9's running off of the (r) ( right) channel
2 5 1/4's running off of the (l) (left) channel

what do i have to do, so i can give the speakers more power, leaving all 4 connected?
this is what they look like now, but the rear speakers get distorted at high bass, at high volume, and i know it's not the limit of the speaker, they just need a little more power.

BTW theese are eclipse audio speakers, they are not cheap speakers, they will have way better sound with more amps, please show me how to do this, while leaving all 4 connected, thnaks

this is what it looks like now

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[DGajre777]

Hook it up like this:

1) Amp left channel
2) wire + of amp to + of 5 1/4 left speaker
3) wire - of 5 1/4 speaker to + of 6x9 left speaker
4) wire - of 6x9 speaker to - of left channel on amp

repeat same for the right channel. Doing this will drop your load to 2 ohms on each channel giving you 125 watts instead of 100 watts. The way you have wired them in your picture, you are running it in series, but splitting the power and your speakers are getting 50 watts each. If you do them the way I mentioned above, you'll get 75 watts each AND your channels with be routed correctly.

 

[RedTurboEclipse]

i have a mtx class d mono amp
and a 12" kicker 4 ohm sub

i dont have the official numbers but the mtx amp is rated at putting out ~300 with a 2ohm load.. and ~200 with 4ohm.. the sub max watt is 300.. theres no way to get the most power from the amp/sub unless i get a new sub at 2 ohms correct? i hear these things about bridging but ive read with mono class d amps its bridged internally so this doesnt apply..