Subwoofer to Amp Wattage

fatalize
fatalize Posts: 12
edited November 2008 in Car Audio & Electronics
hey all im new to this site, and to car audio setups, i have a 15" sub and box and im wondering how many amp watts should i be looking at per sub watt, like 2:1 or have i got this totally wrong :confused:, please i need some advice :)
i just want really good bass :D
Post edited by fatalize on
«13

Comments

  • exalted512
    exalted512 Posts: 10,735
    edited October 2008
    10,000 watts should be about right a 15".
    -Cody
    Music is like candy, you have to get rid of the rappers to enjoy it
  • MacLeod
    MacLeod Posts: 14,358
    edited October 2008
    fatalize wrote: »
    hey all im new to this site, and to car audio setups, i have a 15" sub and box and im wondering how many amp watts should i be looking at per sub watt, like 2:1 or have i got this totally wrong :confused:, please i need some advice :)
    i just want really good bass :D

    Yeah, youre totally wrong.

    Watts is a measurement of power. Watts on an amp tell you how powerful that amp is. Watts on a sub tell you how much power that sub can withstand. If you have a sub rated at 500 watts then you need an amp that makes 500 watts.
    polkaudio sound quality competitor since 2005
    MECA SQ Rookie of the Year 06 ~ MECA State Champ 06,07,08,11 ~ MECA World Finals 2nd place 06,07,08,09
    08 Car Audio Nationals 1st ~ 07 N Georgia Nationals 1st ~ 06 Carl Casper Nationals 1st ~ USACi 05 Southeast AutumnFest 1st

    polkaudio SR6500 --- polkaudio MM1040 x2 -- Pioneer P99 -- Rockford Fosgate P1000X5D
  • only126db
    only126db Posts: 157
    edited October 2008
    Not all manufacturers tell the truth about power output capabilities or power handling capabilities.

    It is usually safe to get an amp that is rated 25-50% higher rms than the sub you plan on powering.

    Just make sure your gain levels are set to not over power the subwoofer.
  • Jstas
    Jstas Posts: 14,842
    edited October 2008
    only126db wrote: »
    Not all manufacturers tell the truth about power output capabilities or power handling capabilities.

    It is usually safe to get an amp that is rated 25-50% higher rms than the sub you plan on powering.

    Just make sure your gain levels are set to not over power the subwoofer.

    If you listen to this jackass then you deserve what you get.
    Expert Moron Extraordinaire

    You're just jealous 'cause the voices don't talk to you!
  • fatalize
    fatalize Posts: 12
    edited October 2008
    thanks for the help so far, so if i had a 15" sub with a maximum output of 2000W and Max Power of 1200W (Peak Power) what kind of wattage amp should i look for?
  • CRESCENDOPOWER
    CRESCENDOPOWER Posts: 153
    edited October 2008
  • Jstas
    Jstas Posts: 14,842
    edited October 2008
    fatalize wrote: »
    thanks for the help so far, so if i had a 15" sub with a maximum output of 2000W and Max Power of 1200W (Peak Power) what kind of wattage amp should i look for?

    How about you just tell us what subwoofer you have because you are obviously very confused and trying to straighten you out and answer your questions at the same time is frustratingly difficult.




    I would follow the advice in post #4.:D

    And people should listen to you because...???
    Expert Moron Extraordinaire

    You're just jealous 'cause the voices don't talk to you!
  • CRESCENDOPOWER
    CRESCENDOPOWER Posts: 153
    edited October 2008
    Jstas wrote: »
    And people should listen to you because...???

    Oh, come on! Can’t I have a little fun with one of the most elementary audio questions ever asked? OK, I have changed my mind. He should buy an amplifier where its continuous average power rating is 100% higher than the woofer in question continuous power handling. Are you going tell me I’m wrong again? Or, maybe you should do a search for amplifier clipping, or headroom. More power is always the answer when moving large motor structures in subwoofers.
  • Jstas
    Jstas Posts: 14,842
    edited October 2008
    Oh, come on! Can’t I have a little fun with one of the most elementary audio questions ever asked? OK, I have changed my mind. He should buy an amplifier where its continuous average power rating is 100% higher than the woofer in question continuous power handling. Are you going tell me I’m wrong again? Or, maybe you should do a search for amplifier clipping, or headroom. More power is always the answer when moving large motor structures in subwoofers.

    You came in here and your first post was supposed to be sarcasm. It was also in support of a known and self-avowed troll who has threatened to "bring all of his friends" here to show us all what's up. Usually, for most people, post number 1 is a "Hey, how ya doin'?" kind of post.
    Expert Moron Extraordinaire

    You're just jealous 'cause the voices don't talk to you!
  • Jeff Beaird
    Jeff Beaird Posts: 217
    edited October 2008
    fatalize wrote: »
    hey all im new to this site, and to car audio setups, i have a 15" sub and box and im wondering how many amp watts should i be looking at per sub watt, like 2:1 or have i got this totally wrong :confused:, please i need some advice :)
    i just want really good bass :D

    OK, before this gets out of hand....
    Fate, which model 15" sub do you have and what size box? Ported, sealed..?
    A little more info please.
    Thanks, Jeff...
  • Jstas
    Jstas Posts: 14,842
    edited October 2008
    OK, before this gets out of hand....
    Fate, which model 15" sub do you have and what size box? Ported, sealed..?
    A little more info please.

    Asked that already. He hasn't answered.

    Oh and thanks for being our savior.
    Expert Moron Extraordinaire

    You're just jealous 'cause the voices don't talk to you!
  • CRESCENDOPOWER
    CRESCENDOPOWER Posts: 153
    edited October 2008
    only126db wrote: »
    Not all manufacturers tell the truth about power output capabilities or power handling capabilities.

    This is correct! Most peak, or continuous power ratings are wishy washy at best.
    only126db wrote: »
    It is usually safe to get an amp that is rated 25-50% higher rms than the sub you plan on powering..

    This is correct! Over powering any subwoofer of any type will lower your chances of blowing the woofer.
    only126db wrote: »
    Just make sure your gain levels are set to not over power the subwoofer.

    This is the correct answer for any car audio amplifier. Good advice, even if you are a troll.
  • CRESCENDOPOWER
    CRESCENDOPOWER Posts: 153
    edited October 2008
    Jstas wrote: »
    You came in here and your first post was supposed to be sarcasm. It was also in support of a known and self-avowed troll who has threatened to "bring all of his friends" here to show us all what's up. Usually, for most people, post number 1 is a "Hey, how ya doin'?" kind of post.

    Hi everybody! My home/car audio experience runs from roughly “83” to present time. My home theater experience runs from the early “90s” to present time. My headphone experience runs from the late millennium to present. My love for music started at around age 6 listening to the radio. I am probably the most open minded individual one could possibly meet, and it was only a matter of time that I actually joined the forum of the loudspeaker manufacturer that I have recommended more of their products to people "not in the know" than any other. I believe it is very difficult to develop products to satisfy the audiophile, and the music lover at the same time. This is something Polk Audio over the years has excelled at within its price range.
  • exalted512
    exalted512 Posts: 10,735
    edited October 2008
    This is correct! Over powering any subwoofer of any type will lower your chances of blowing the woofer.

    logically, how does this make any sense at all?
    -Cody
    Music is like candy, you have to get rid of the rappers to enjoy it
  • only126db
    only126db Posts: 157
    edited October 2008
    exalted512 wrote: »
    logically, how does this make any sense at all?
    -Cody

    Not sure if he meant overpowering, more like running clean power in excess of a quality manufacturers recommendations.(this is done frequently and with great success)

    Running dirty clipped power above or below manufacturer recommendations will stress your amplifier and heat up your voice coils due to amps sending an intermitent dc current to the sub which they are not made to handle and will likely damage the speaker.(this is done frequently with terrible results)
  • only126db
    only126db Posts: 157
    edited October 2008
    Jstas wrote: »
    If you listen to this jackass then you deserve what you get.

    I'm still waiting for you to prove me wrong in anything.....

    My subs still work, sound better than they did sealed(above 30hz) they are being powered by an amplifier over manufacturer suggested power. I have had not one problem with my setup, I get no light dimming running 2600 watts of amplification off a single battery and 60 amp alternator.

    I have never had one person say the sound of my system is anything but great, from shop owners, installers, the mail man, neighbors, people at the one competition I went to, cruises, the friggin grocery store, driving next to me etc.

    Now to say if you listen to me you get what you deserve, I am going to take that as a compliment and would tell all, yes listen to me and you will get what you deserve, a quality very capable sound system with no issues that you can enjoy for years to come.
  • exalted512
    exalted512 Posts: 10,735
    edited October 2008
    Theres no way youre getting 2600w off of a 60A alternator. Its physically impossible.
    -Cody
    Music is like candy, you have to get rid of the rappers to enjoy it
  • MacLeod
    MacLeod Posts: 14,358
    edited October 2008
    only126db wrote: »
    Running dirty clipped power above or below manufacturer recommendations will stress your amplifier and heat up your voice coils due to amps sending an intermitent dc current to the sub which they are not made to handle and will likely damage the speaker.(this is done frequently with terrible results)

    OVERPOWERING is the ONLY thing that kills a speaker. You either build up more heat than the voice coil can dissipate or you push the suspension beyond its mechanical limits. The only way to do that is by overpowering. And it doesnt matter if that signal is clipped or clean.
    Most peak, or continuous power ratings are wishy washy at best.

    Peak power ratings are worthless however RMS ratings are usually pretty close to being on in terms of amplifiers. In all the test reports Ive read on amps, Id say better than 98% meet their rated power and the ones that come in under are only a few watts off. Buy a quality name brand amp and you can pretty much be rest assured youre getting the watts youre paying for.
    Over powering any subwoofer of any type will lower your chances of blowing the woofer.

    Nope. Buying a bigger amp than your speakers are rated to handle does mean youll have more headroom to play with but it also means it will be EASIER to blow your speakers.
    so if i had a 15" sub with a maximum output of 2000W and Max Power of 1200W (Peak Power) what kind of wattage amp should i look for?

    Ignore the peak/max rating of anything audio related. Subs dont have an "output rating". That is a rating of how much power the sub can handle thermally and mechanically. If your sub is rated at 500 watts RMS then you need to find an amp that makes 500 RMS.
    Not all manufacturers tell the truth about power output capabilities or power handling capabilities.

    Yeah, actually they do. Over the years Ive seen virtually every make of amp tested and reviewed in different magazines and such and Id say 99% of them easily met their rated specs. Granted there have been some like Hifonics and Alphasonik that have fell short but it wasnt by more than a few watts. So long as youre buying a quality name brand amplifier you can be rest assured that youre getting the watts you payed for and probably a little more.
    polkaudio sound quality competitor since 2005
    MECA SQ Rookie of the Year 06 ~ MECA State Champ 06,07,08,11 ~ MECA World Finals 2nd place 06,07,08,09
    08 Car Audio Nationals 1st ~ 07 N Georgia Nationals 1st ~ 06 Carl Casper Nationals 1st ~ USACi 05 Southeast AutumnFest 1st

    polkaudio SR6500 --- polkaudio MM1040 x2 -- Pioneer P99 -- Rockford Fosgate P1000X5D
  • CRESCENDOPOWER
    CRESCENDOPOWER Posts: 153
    edited October 2008
    Please use a little common sense here. No one is going to blow a woofer by having too much power unless they are trying to. The sound of a woofer being purposely pushed that hard sounds unacceptable, and your ears and a little common sense should be enough to tell one to turn down the volume.
    I have taken bookshelf speakers with a one-inch tweeter, and a 6 ½ woofer and ran 500 watt per channel mono blocks on them to the point that they were physically moving back and forth on the bookshelf with no damage. I could imagine what would happen if I had done that same thing with a 50 watt per channel receiver that was bought from Best Buy. If someone blows a woofer with too much power they deserve it.
  • eloplayspolo
    eloplayspolo Posts: 1,117
    edited October 2008
    Oh. I'm convinced.
    2013 Toyota Prius
    Audible Physics 3 Way: H6MB, AR3-A, AR2.0
    Image Dynamics iDMax 12" D2v4
    (2) Alpine PDX-V9 Bridged, Alpine PDX-M12 (500w Mid-Bass, 200w Mid, 200w Tweet, 1200w Sub)
    Mosconi 6to8 v8
  • CRESCENDOPOWER
    CRESCENDOPOWER Posts: 153
    edited October 2008
    Oh. I'm convinced.

    Are you? Well, I guess if I can’t beat ‘em I must join ‘em. One should use his CD deck to drive his, or her subwoofers. Crank ‘em up boys! :D
  • eloplayspolo
    eloplayspolo Posts: 1,117
    edited October 2008
    the problem is that u join the forum..... and ur first post ur a jackass.... and ur next few posts argue with professionals who make 1000s of posts on this site and 1 of which has a pretty damn good record wining many competitions.

    Idk how old u are but ur never going to get through life by arguing with more informed people on a topic if u can never admit that maybe they do know more than me and maybe if i just shut my mouth and learn something ill become a better informed person.

    But u run along and argue with Phill Jackson and tell him that the lakers offense is all wrong.
    2013 Toyota Prius
    Audible Physics 3 Way: H6MB, AR3-A, AR2.0
    Image Dynamics iDMax 12" D2v4
    (2) Alpine PDX-V9 Bridged, Alpine PDX-M12 (500w Mid-Bass, 200w Mid, 200w Tweet, 1200w Sub)
    Mosconi 6to8 v8
  • exalted512
    exalted512 Posts: 10,735
    edited October 2008
    Please use a little common sense here. No one is going to blow a woofer by having too much power unless they are trying to. The sound of a woofer being purposely pushed that hard sounds unacceptable, and your ears and a little common sense should be enough to tell one to turn down the volume.
    I have taken bookshelf speakers with a one-inch tweeter, and a 6 ½ woofer and ran 500 watt per channel mono blocks on them to the point that they were physically moving back and forth on the bookshelf with no damage. I could imagine what would happen if I had done that same thing with a 50 watt per channel receiver that was bought from Best Buy. If someone blows a woofer with too much power they deserve it.

    Maybe you're not understanding, so let me try to make it as clear as possible.

    OVER POWERING A SPEAKER IS THE ONLY WAY TO KILL IT.

    I've seen many speakers blow under conditions where you can not audibly hear the speaker meeting its mechanical limits, but it was getting pushed passed its thermal limits.

    Having headroom is just fine. If you have a 500 watt subwoofer and a 1000 watt amp, that is fine, if you set the gains accordingly. But then don't turn around and say I have a 1000watts going to my 500w sub and its doing fine. No, you have 500 watts going to a 500w sub and its doing fine.

    Also, its highly unlikely your bookshelf system was getting anywhere near 500w rms and it not blow unless you only played it for less than 15 seconds.

    -Cody
    Music is like candy, you have to get rid of the rappers to enjoy it
  • rdb2001
    rdb2001 Posts: 791
    edited October 2008
    I am new to polk forums but have been in home theater and car audio for years. Anybody that knows anything about car audio knows that your chances are greater to blow a speaker when you are underpowering it. Now i am not saying go hook up a 500w rms sub to 1000 watt rms speaker, but if you have a amp thats rated a little higher in watts than your sub then you should be ok as long as you keep your gain set at a nice level.
  • only126db
    only126db Posts: 157
    edited October 2008
    MacLeod wrote: »
    OVERPOWERING is the ONLY thing that kills a speaker.


    If you feel like learning something than read this entire article or just take not to this particular line.....

    "clipping with real-world (speech or music) signals creates not only the harmonics that have been described in innumerable web pages, but also generates a subsonic signal that is potentially very damaging to drivers, but is never mentioned. This signal has the capability to cause driver damage at worst, or unwanted cone modulation and additional loudspeaker distortion at best - neither can be considered a desirable outcome."

    http://sound.westhost.com/clipping.htm#s21
  • only126db
    only126db Posts: 157
    edited October 2008
    exalted512 wrote: »
    Theres no way youre getting 2600w off of a 60A alternator. Its physically impossible.
    -Cody

    It is possible, but not continuously.

    Now if running completely off of a 60 amp source, no it's not possible, but with the momentary current output of a battery a 2600 watt peak is not out of the question.
  • exalted512
    exalted512 Posts: 10,735
    edited October 2008
    rdb2001 wrote: »
    I am new to polk forums but have been in home theater and car audio for years. Anybody that knows anything about car audio knows that your chances are greater to blow a speaker when you are underpowering it. Now i am not saying go hook up a 500w rms sub to 1000 watt rms speaker, but if you have a amp thats rated a little higher in watts than your sub then you should be ok as long as you keep your gain set at a nice level.

    Are you reading what you type? How does it make sense, logically, that underpowering a speaker will kill it? That is equivalent to saying that driving your car 10 mph under the speed limit will kill it faster than putting the pedal to the floor all the time. IT MAKES NO SENSE.
    only126db wrote: »
    It is possible, but not continuously.

    Now if running completely off of a 60 amp source, no it's not possible, but with the momentary current output of a battery a 2600 watt peak is not out of the question.

    I thought you were talking about continuous. Even still, if you get 2600w spikes off a single battery, your lights will dim. If you're not getting dimming, youre not getting 2600w.
    only126db wrote: »
    If you feel like learning something than read this entire article or just take not to this particular line.....

    "clipping with real-world (speech or music) signals creates not only the harmonics that have been described in innumerable web pages, but also generates a subsonic signal that is potentially very damaging to drivers, but is never mentioned. This signal has the capability to cause driver damage at worst, or unwanted cone modulation and additional loudspeaker distortion at best - neither can be considered a desirable outcome."

    http://sound.westhost.com/clipping.htm#s21

    When an amplifier clips, it can send on average 4x the amount of power to a driver as normal. So if you have a 50w speaker and a 50w rms amplifier, and it clips, youre sending about 200w to that speaker.

    what does that mean? YOURE OVERPOWERING THE SPEAKER.

    Now lets say you have the same 50w speaker, but a 10w amplifier. You push the amplifier into clipping, its now producing 40watts. Fortunately, the speaker can handle 50w. Your speaker is going to be fine. Why? BECAUSE ITS STILL GETTING UNDERPOWERED.

    Its very simple really, I'm not sure if anyone else has said this yet, but...

    THE ONLY WAY TO KILL A SPEAKER IS BY OVERPOWERING IT.
    -Cody
    Music is like candy, you have to get rid of the rappers to enjoy it
  • rdb2001
    rdb2001 Posts: 791
    edited October 2008
    What kills me on here is that everyone on here who have a millions of post thinks they are gods gift to sound and speakers. You obviously dont know much about what you are saying. Read up on an speaker, under powering the speaker hurts that speaker more than overpowering, hence why speakers 9 times out of time have bad sound quality when being underpowered. Before you type read up on what you are saying. Just because you are on polk, that doesnt mean you know everything. I have found that all the regulars on here seem to think they know everything and try to gain up on new people who have the same or more knowledge than you might have. I compete in the car audio relm and know what I am talking about. I never said you can overpower it alot, but you can blow it easier underpowering it than overpowering it a little. So before you go telling me what I dont know what do you have to prove you even have a system and I am not talking about posting what you have. I mean pictures. Because alot of you get on here and claim to have so much but probably dont have any of what u say.
  • only126db
    only126db Posts: 157
    edited October 2008
    Ya know, its funny I run into so many conflicting theories on underpowering speakers, I'm begining to think nobody really knows...

    JBL says clipped signals will kill a speaker...

    Rane says no they wont.....

    Yet I have burnt woofers in years past by over driving the amplifier.

    I have also used many speakers well over their rms ratings with very good results.

    And exalted512, I will test my amplifier output just for you, I have a program I am wanting to test out and see for my self what my system does, of course it will be test tones, I will evaluate using a couple tones and relay the info to you and let you know what my Polks are handling in their ported boxes...