Amp Ohm Ratings

[wrightie]

My Kenwood amp says it is 200W rms by 1 at 4 ohms
400W rms by 1 at 2 ohms
and 500W rms by 1 at 1 ohm.
I am confused because my amp is a mono block amp and has a set of speaker terminals for the left and the right. when i have both subs running what am I running at? how do I wire it at one ohm to take advantage of the power gain?

Help
Wrightie

[jamcllw]

What Ohms are you speakers?

[Travis99Alero]

it all depends on your subs.

[rowdygls]

a little diff type of question but along the same lines. i understand the hook ups for subs and their ohm values. my question is, taking wrightie's amp as example of 500 watts rms by 1 at 1 ohm is i'm guessing bridged. now here is my question...i hook two 4 ohm subs in parallel (300 watts rms each) so total impedence is 2 ohms. What is my watts value???

[mikegett]

The wattage value of a sub does not change. If the rms is 300 watts then you should not exceed 300 watts rms at any ohm.
Writie, your amp does not change ohms. A sub will have a ohm rating (refering to its drivers impedence). The ohm rating will change deepending on how it is wired with another driver. By wiring drivers in parallel the ohms are cut in half. If wired in series the values will be added togeather. A amplifier will rate its output at given ohms. The lower the impedence (ohms) the more amps the amplifier will pull (creating more wattage for the speakers). The problem is that the added impedence creates heat. For this reason some amps can be wired to 1 through four ohm drivers. Pay special attention to this and read up on it. Wiring a sub or speaker in a lower impedence can drasticly shorten the life of your amp.

[wrightie]

how do you wire in series? how do you wire in parallel? My subs are 4 ohm apiece and am curious if I can get more power out of my amp right now. Only 2 subs are hooked up to the amp right now and want to know if I can run all 3 with enoough power to make them hit.

Wrightie

[eag182]

My sony amp specifically says not to go under 4ohms, so check your own manual.

The manual for you sub should also include some info on resistence, specifically the parallel (Re^-1 = R^-1 + R^-1 +...) and series (Re = R1+R2+...)

[rowdygls]

here's a wiring diagram for ya.

http://www.crutchfieldadvisor.com/S-uNe8p8...&impedance=SVC4 (http://www.crutchfieldadvisor.com/S-uNe8p8x1d4m/learningcenter/car/subwoofers_wiring.html?subs=3&impedance=SVC4)

[rowdygls]

with that link it shows you how to do some other diff wiring diagrams. it also shows subs wired in parellel and series.

[bigd6983]

Originally posted by mikegett@Mar 8 2005, 05:21 PM
The wattage value of a sub does not change. If the rms is 300 watts then you should not exceed 300 watts rms at any ohm.
Writie, your amp does not change ohms. A sub will have a ohm rating (refering to its drivers impedence). The ohm rating will change deepending on how it is wired with another driver. By wiring drivers in parallel the ohms are cut in half. If wired in series the values will be added togeather. A amplifier will rate its output at given ohms. The lower the impedence (ohms) the more amps the amplifier will pull (creating more wattage for the speakers). The problem is that the added impedence creates heat. For this reason some amps can be wired to 1 through four ohm drivers. Pay special attention to this and read up on it. Wiring a sub or speaker in a lower impedence can drasticly shorten the life of your amp.
and as you decrease the impedance your amp is seeing the harder its working and the hotter its going to get........heat and electrical components go hand in hand.....the hotter something gets it loses its ability to produce a clean and clear signal regularly.....some amps are rated down to 1 ohm and some even lower.....in my opinion you are shortening the lifespan of your amp way too greatly by doing that just like mikegett said.......

heres a little something to kick at you guys......say you have a 2 channel amp, bridgable to say 800 watts rms......you got 2 subs, dual voice coiled at 4 ohms.......heres what you do......take each sub, and wire the coils in series, (you have positive going into speaker, its negative into the other positive, and the ground back to the amp....)do that to each speaker and that puts each speaker at 8 ohms........now run both of speakers bridged in parallel and you are taking full advantage of bridging your amp, its keeping your amp at a conservative 4 ohms(extending its life)......and your speakers are more than likely getting enough power.....

[mike2002]

no offense bigD, but i never take your posts seriously, because i look at your avatar and in your picture you look EXACTLY like my older brother, it looks like it could be a picture of him....lol....sorry for jacking the thread

[eag182]

Same here. Looks worried

[bigd6983]

Originally posted by mike2002@Mar 8 2005, 07:58 PM
no offense bigD, but i never take your posts seriously, because i look at your avatar and in your picture you look EXACTLY like my older brother, it looks like it could be a picture of him....lol....sorry for jacking the thread
lol dont worry man.......feel the same way, 1/2 the time it seems u dont fully know what ur talkin about......and the post a picture comment thread is in the off topic section.....just in case u were wondering.....

[mikegett]

Originally posted by bigd6983+Mar 9 2005, 06:27 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (bigd6983 @ Mar 9 2005, 06:27 AM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-mike2002@Mar 8 2005, 07:58 PM
no offense bigD, but i never take your posts seriously, because i look at your avatar and in your picture you look EXACTLY like my older brother, it looks like it could be a picture of him....lol....sorry for jacking the thread
lol dont worry man.......feel the same way, 1/2 the time it seems u dont fully know what ur talkin about......and the post a picture comment thread is in the off topic section.....just in case u were wondering..... [/b][/quote]
I think this is due to the fact that half of the time we don't know what we are talking about. And the other half we are just fooling ourselves into believing we do know what we are talking about. Or so my wife leads me to believe. B)
I liked your response about dual voice coils. It helps to show the versatility of dual voice coils.

[wrightie]

Hey rowdy thanks for the wiring diagrams they were very helpfull. I tried some different configs but it really doesnt seem to make a big difference anyway I have it. Oh well what can ya do.

Wrightie

[Travis99Alero]

get subs that can handle more power, and buy an amp that can put out more power.

[bigd6983]

lol very well put travis99.......unfortunately that usually includes breaking the bank.....

and thanks mikegett.......you can get kinda creative, use amps that most people wouldnt think to use......like my interior speakers......all 4 corners are run off of one channel utilizing what i explained up there, the amp is 80x2 or 220x1 @ 4 ohms rms.......80x2 isnt what i needed and i didnt wanna run it at 2 ohms......so i put my electronics degree to work lol......

[mike2002]

Originally posted by bigd6983+Mar 9 2005, 12:27 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (bigd6983 @ Mar 9 2005, 12:27 AM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-mike2002@Mar 8 2005, 07:58 PM
no offense bigD, but i never take your posts seriously, because i look at your avatar and in your picture you look EXACTLY like my older brother, it looks like it could be a picture of him....lol....sorry for jacking the thread
lol dont worry man.......feel the same way, 1/2 the time it seems u dont fully know what ur talkin about......and the post a picture comment thread is in the off topic section.....just in case u were wondering..... [/b][/quote]
i think i know what im talking about, but you just dont understand :P

just saying you look like my brother so it seems kind of wierd

[jamcllw]

bigd that has got to sound like poop

[bigd6983]

why would it sound like poop? the only thing im sacrificing is the abiliting to adjust left and right and front and back.......its like the amp sees one 4 ohm speaker.....the thd factor is i think a little bit higher when bridged but not really noticable until you really get high up in the power levels........trust me it works.......

[jamcllw]

There's no separation. Your sending the same frequencies to the smaller front speakers and the the larger rear speakers. The fronts cant handle some of the lower frequencies that the rears can and adversly the larger rear speakers cant handle some of the higher frequencies. There's no depth to the sound. There's no stereo sound. Your transmitting in mono 1960s style. Personally I would have wired the front speakers to 4 ohms running off of the amp with the rear speakers operating on headunit power until I could save up enough money to get another amp.

Sound is opinion based and you may like but I don't think I would. I have to have my stereo sound and have the ability to adjust the frequencies going separate speakers.

[mikegett]

It deepends on his HU. More than likely, it is sending all frequencies to every channel. Few Hu's have a built in crossover dedicated per channel. Our factory HU's do the seperation at the amplifier. As for stereo, he would still have it. The amp will have a left and right channel from the HU or he couldn't bridge it. The difference is that he won't have the frequencies flowing from left to right as heard in some songs. Not much of a deal since most artists since pink floyd have abandoned this. I would still opt for the versatility of the multi channels, but you do what your wallet will allow.

[bigd6983]

yea thats what im saying.....i have nice crossover settings on my amps........none of the door or deck speakers see any bass notes, thats what my subs are for.......and as far as high frequencies......the 6x9 handles them fine trust me, for stock speakers ud be blown away at how good it sounds, it sounds better then anyone of my friends that run their interior speakers off their decks.......granted it would sound so much better with some nice infinity's all the way around but it sounds fine for now.......i plan on getting an in dash eq for more adjustments but for now it sounds good.......

[mikegett]

Skip the indash eq. Put the money toward a 30 band parametric. They tend to be 2 channel only and will require two for fronts and back. The difference in flexibility is well worth it. It also kicks ass on any eq or dsp built into a head unit.

[mike2002]

mike, i think you misread. if you have a 2 channel amp and you bridge it to 1 channel, which he did, you dont have stereo, you have mono. all the speaks will be getting the same freq range to, but i dont know what he's runinng to say if thats good or bad. either way, i wouldn't do it...like someone said, stereo came out a long time ago for a reason

id hook the 2 left speakers to 1 output, the other 2 to the other output. that will give you more than 80x2 since its 2 ohms, and sound better too.

and no one on this board has the 10k equipment needed to properly set up a 30band eq

[sound_xtreme]

if the amp is made to handle 1 ohm it wont hurt it one bit. poop i've ran amps at 1/8th ohm that were made to handle 4 ohms for comps, it'll just shut off when it gets a bit hot. lol. but if it is actually MADE to handle 1 ohm it's all good.

[bigd6983]

Originally posted by sound_xtreme@Mar 10 2005, 08:55 PM
if the amp is made to handle 1 ohm it wont hurt it one bit. poop i've ran amps at 1/8th ohm that were made to handle 4 ohms for comps, it'll just shut off when it gets a bit hot. lol. but if it is actually MADE to handle 1 ohm it's all good.
lol thats nuts.........i know my amp isnt capable of going that low, and i dont even know about 2 ohm stable......i just dont want it getting hot......and all you guys cant talk crap if you dont know what it sounds like......for regular music it sounds good 2 me........99% of people wont know the difference.......ive had friends in the car that no there crap and when i tell them they are like really i cant hear a difference......the only time i can tell is when playing movies.......but either way its going to sound like crap until i get something that utilizing the dolby 5.1 and i get it sounding good........then i will do what i gotta do and seperate it all......

but for now its fine, most of you wouldnt know just by hearing it.........

i think running speaks off the deck is the crappiest way to do it, crappy sound, bass coming through interior speakers even 6x9's sounds like junk........

and mikegett im with you on the 30 band, i think i could spend hours messing with that thing lol....all the controls ooooooooo, but a nice indash one that gives me some more controls, especially a bass knob that my amp doesnt have so that i can adjust quickly if i wanted to.......id be happy with a nice 15 or so band.......

but that will come later

[mike2002]

any aftermarket amp will do 2 ohm stereo, alot wont do 2 ohm mono, thats the difference. it wont get any hotter than it is now. hade my last car temporarly set up as mono while waiting for my other amp, and it does sound worse

30 band eq will mess up your system. unless of course you have the ten thousand dollars in equipment to set it up, you can easily mess stuff up with that.

[mikegett]

He was merely stating how to take advantage of the amplifiers output. I agree that I would prefer to run the right and left channel to my speakers. However, this does not mean that he does not have all of his frequencies. In some cases bass frequencies are sent via the right channel. Some are broadcast in stereo (allowing the seperation from left to right) but this is seldomly used today in audio cd's. Most cd's send all frequencies to each channel. If they do have stereo, all frequencies will be merged when he bridges the amplifier. This is why bridging uses the left of one channel and the right of the other. To allow all frequencies to be used in a mono setup. (most amps have a switch for allowing stereo to be broadcast in bridging) If you think that it can't sound good then look at some of the newer HU's like my 8454. In pro mode one set of rca's can be used for highs, one set for mids and one for lows to allow a three way setup without crossovers. In this case, one amplifier could be used for all four tweeters, one for all mids and the last for your sub.
A thirty band is not much harder than a five band. A five band will have a much larger Q factor and affect a wider range. I find it way more difficult to center in on the frequencies this way. As for the equipment, a scope can be bought on ebay for fairly cheap. Otherwise, quite a few HU's are building in a mic for testing your dips. My eclipse does a pretty good job of it. The big thing to remember is that your ears are the final judge for your enviornment. What may be exceptable for one person may be wrong for someone else.

[bigd6983]

very well put mikegett......and a 30 band would be fun but maybe a bit of an overkill in an everyday vehicle lol.......i think a 15 band or around there would be perfect for what i wanna do and would allow a nice adjustability.......but like i said for right now 95% of the audio coming out of my speakers is from cd's, i dont usually have a lot of passengers or go on long trips enough to use the ps2 so for right now the left and right thing doesnt bother me too much, but once i drop money on some nice speakers, bigger amp for some 12's ill do it right and spring for a nice 4 channel amp......

and mike2002 to say something doesnt get hotter when dropping from 4 to 2 ohms is rediculous, when you do that your pulling more power, thats gonna make your transistors and what not work harder, and they are going to get hotter, heat will slowly and i stress slowly break down your amp.......i deal with amplifiers everyday trust me, i can see and feel the difference when bridging channels......

[mike2002]

Originally posted by bigd6983@Mar 11 2005, 07:45 PM
very well put mikegett......and a 30 band would be fun but maybe a bit of an overkill in an everyday vehicle lol.......i think a 15 band or around there would be perfect for what i wanna do and would allow a nice adjustability.......but like i said for right now 95% of the audio coming out of my speakers is from cd's, i dont usually have a lot of passengers or go on long trips enough to use the ps2 so for right now the left and right thing doesnt bother me too much, but once i drop money on some nice speakers, bigger amp for some 12's ill do it right and spring for a nice 4 channel amp......

and mike2002 to say something doesnt get hotter when dropping from 4 to 2 ohms is rediculous, when you do that your pulling more power, thats gonna make your transistors and what not work harder, and they are going to get hotter, heat will slowly and i stress slowly break down your amp.......i deal with amplifiers everyday trust me, i can see and feel the difference when bridging channels......
i didn't say that. your completly contridicting yourself, you say it gets hotter because it pulls more power, but you bridge it to pull more power? to say a amp doesn't get hotter when you bridge it is rediculos...they get hotter in both cases. either way you look at it, they going to put out about the same amount of power, 1 way is stereo, 1 way is mono, it was just a suggestion. you do get more power when you bridge it, thats obvious. but do you get more power bridged at 4ohms vs stereo at 2ohms? no, not really. ive worked with alot of car electronics too, i tend to hang around my brothers shop alot, bs with the venders when they come in, or with my brother who owns a shop and his own speaker line, and your not the only person with a AAS in a electrical field.... i dont know why you feel this needs to be a pissing contest


sound_xtreme : the amp will shut off when it overheats, but ive seen it a dozen times where the amp keeps shutting off and eventually wont turn on. those protections dont last forever.

[bigd6983]

what i mean was runnin a pair of speakers off one channel will get you to 2 ohms, but what im doing is bridging the left and right channel........so im keeping it at 4 ohms

everything im stressing deals with 2 ohm and 4 ohm.......it does work harder at 2 ohms than 4 ohms......when you drop down to 2 ohms the thd factor is greater because of the fact the components are working harder and getting a little warmer.......thats all im saying......and mind you your the one singling me out most of the time..........and why dont u be a lil open minded, just cuz you know something doesnt mean u cant learn more about it....

if someone does something a certain way and understands what hes doing and what hes sacrificing then let it be......aint no reason to say its stupid, or i wouldnt do it, or blah blah........

people come on here to learn, to show people new things.....

[mike2002]

Originally posted by bigd6983@Mar 12 2005, 06:10 PM
what i mean was runnin a pair of speakers off one channel will get you to 2 ohms, but what im doing is bridging the left and right channel........so im keeping it at 4 ohms

everything im stressing deals with 2 ohm and 4 ohm.......it does work harder at 2 ohms than 4 ohms......when you drop down to 2 ohms the thd factor is greater because of the fact the components are working harder and getting a little warmer.......thats all im saying......and mind you your the one singling me out most of the time..........and why dont u be a lil open minded, just cuz you know something doesnt mean u cant learn more about it....

if someone does something a certain way and understands what hes doing and what hes sacrificing then let it be......aint no reason to say its stupid, or i wouldnt do it, or blah blah........

people come on here to learn, to show people new things.....
im not singling you out, i was making a suggestion. yes when you run at 2 ohm stereo it gets hotter than 4 ohm stereo, but 4 ohm bridged also gets hotter than 4 ohm stereo. what im saying, is 2ohm stereo gets as hot as 4ohm bridged.

also, you say the distortion goes up when you go from 4 ohms to 2 ohms, it also goes up when you go from 4ohm stereo to 4ohm bridged. Both methods have the same amount of distortion. running at 4 ohms bridged is just as hard on the amp as 2 ohm stereo, both wear it more than 4ohm stereo.

all of the drawbacks and benifits of going to 2 ohms are the same as bridging and staying at 4ohms, but you can keep stereo if you wire it differently.....im not going to keep beating a dead horse, ill stop posting on this

[BLK03GXS]

Originally posted by Travis99Alero@Mar 9 2005, 11:56 PM
get subs that can handle more power, and buy an amp that can put out more power.
Screw that... haha just buy some cheep crap like MA audio thats rated (jbf) and run it at like 18.5volts... and at one ohm, then you have all the power ya need B)
lol

And for some saying that decks cant/dont have good equalzation..
my deck Alpine 9835

Quote from Performance auto and sound last month...
"Five years ago, you needed a hide-away processing box the size of a second head unit and an amplifier at least that size again, to achieve what Alpine has done with the CDA-9835"
"Up first is preamp voltage. The 9835 was capable of producing a very strong maximum unclipped output voltage of 4.80V with an output impedance of 322.5§Ù. Power output was stunningly impressive at a full 27.5WRMS. Yes folks, a real 110W head unit. "

http://www.pasmag.com/gear/testreport_article.asp?ID=378

IMO 30 band eq's are the way of the past for your average vehicle.
Get a headunit that can do it all and forget about the wireing hassles, and having to mount all that extra garbage. I have installed a few and unless your spending 1000's of dollars to get the proper speakers (componants of course) and amps and an awsome source unit, dont waste your time with an Eq.

[turtles_ride]

personally, i listen to alot of techno and electonica type music that uses the left to right speaker fading that setting up your system in stereo provides. So i always keep my shizzle seperate, except for my subs (i usually bridge those). I'm excited cuz i got a 7band EQ to hook up this spring and it has 3 sets of rca outputs for subs mids and highs, as well as having 2 rca inputs that i'll hook my ps2 into, and its also got a headphone jack input on the front to hook up my mp3 player. No need to hookup my accessories to an FM transmittor anymore, or the tape deck thingy (i'm still using my factory HU).

[bigd6983]

yea if i listened to a lot of techno id prolly have to have every channel seperate.......i have 40x4 rms alpine amp sitting in my room but i need a little more power than that running the insides otherwise id probably use it....

[mikegett]

Stereo doesn't make much of a impression on me either. Unless I am listening to Pink Floyd or David Bowie. You have to have the whole affect with dark side of the moon. :thumbsup: Otherwise I could do without it as well.
Mike2002 was right about 2 ohm stereo versus 4 ohm bridged. There is no sonic benefit or reduction in heat at 4 ohm bridge. They both pull the same amount of amps and will produce the same THD.

[bigd6983]

then how come i can bridge an amp into 4 ohms and i have no problems but if i run it at 2 ohms for too long it overloads?

[BLK03GXS]

Mike was wrong in saying that a 2ohm and 4 ohm load create the same load on the amp, they are differant, the 2 ohm load being half the load will create more heat, and more power thus more likely hood of a shutdown.
Most modren amps can handel a 2 ohm load but depends on the amp some are 4 ohm bridged 2 ohm non bridged, meaning that the total impedance accross all chanels is still no lower than 4 ohms. Bridgeing the amp down shouldnt effect the SQ of it much, but it will increase the heat output of the amp if its not designed to handle it or if its not a regulated power supply...

[mikegett]

I : current, measured in amps
V: voltage, measured in volts
R: resistance, measured in ohms
P: power, measured in watt

Ohm's law:Current = Voltage/Resistance or I = V/R
Power equation:Power = Voltage^2/Resistance or P = V^2/R

A amp bridged in four ohm or running 2 ohm stereo will pull the same amps. By bridging the channels it can now pull twice the voltage to quadrouple the theoretical wattage. In 2 ohm the amp will pull half the voltage at the same amps to produce two channels at double the theoretical wattage. The end result is the same.

[mike2002]

Originally posted by bigd6983@Mar 14 2005, 08:44 PM
then how come i can bridge an amp into 4 ohms and i have no problems but if i run it at 2 ohms for too long it overloads?
you can run your amp at 2 ohms, just not 2 ohms bridged. the load of 2ohm stereo is the same as 4 bridged, so 2ohm bridged is twice as much as 2ohm stereo basically

i couldn't imagine ozzy or metallica without stereo...but i guess it depends on what you listen to, i notice stereo more on 80's music than newer stuff. they still use stereo, but not like it use to.