Subwoofer RMS question

[BigWill]

Allright people. I'm Looking to get a Vibe subwoofer with 1000 watts RMS
the amplifier I'm lookin to get is 1200 RMS at 4 Ohms.

If I ran the sub with 1200 RMS with there be any repercussions e.g. blowing a new sub
if there are any problems, I'll upgrade to the 15" 1200 RMS sub
Thanks for any help

 

[Icecavern]

Nope it'll be fine, just turn the amp down a bit if you hear distortion.

 

[Adam R]

1200 W RMS... you serious / are your sure its RMS? why on earth do you want all of that power.

Anywho back on question. look at the sub and amps rated 'peak power' which is always what they say.. your peak power for your amp would be around 1700w depending on its efficiency.

what you need to do is look at the specs for the sub and see if it can handle thast peak power and for how long as that is what kills a sub.

also if you only have your gain half way up on your amp you wont be running the full 1200wrms so you could be running a 800wrms if you never turned the amp up fully.

Also, sometimes big and powerfull wont give you the best out of your sound system.


as a little off topic in my ibiza i have a crappy 12" sub (350wrms) and an amp supplying it (250wrms) and to be honest with you i have the gain turned up to about 1/4 - 1/3.

 

[BigWill]

Cheers for the help lads

 

[Poverty]

Gain settings are dependant on your headunit voltage output. To set the gains properly you need to get it scoped. The vibe sub will take more than 1000rms. Just make sure you dont turn the amp up so high it will distort. Also you might have to uprgarde your vehicles powersupply to cope with the 1200rms demand.

 

[BigWill]

Also you might have to uprgarde your vehicles powersupply to cope with the 1200rms demand.

Just so I'm completely clear on it,what exactly would I have to upgrade, like a higher performance battery or what? Cheers for the help

 

[Adam R]

asking for 1200RMS from a standard car battery is a bit stupid if your running this sub at high power. in no expert at this but im sure you would need a few more supporting batteries aswell as a couple of capacitors to help smooth the power delivery.

 

[BigWill]

Maybe I'll stick to a lower power sub for now then. Till i get some more cash eh

 

[Adam R]

im going to a question i asked earlier.... what do you want from your sound system ? clear clean sound ? or massive bass that a whole city will be able to hear.

1200RMS subs are pretty intense, why do you need something like that ? my sub peaks is 250w rms and to be honest it sounds pretty good, haveing something thats nearing the 1200wrms is show level stuff .. isnt it ?

 

[BigWill]

to be honest, the music I listen to is more Dancey than 3 second 20hz bass so a nice loud punch than a wailing everlasting bass note would be more to my liking.... But then again I'm undecisve in music and listen to everything so sometimes I'd ike my eardrums to bleed

Edit: sorry I didn't answer you first time

 

[Icecavern]

1200 W RMS... you serious / are your sure its RMS? why on earth do you want all of that power.

Anywho back on question. look at the sub and amps rated 'peak power' which is always what they say.. your peak power for your amp would be around 1700w depending on its efficiency.

what you need to do is look at the specs for the sub and see if it can handle thast peak power and for how long as that is what kills a sub.

also if you only have your gain half way up on your amp you wont be running the full 1200wrms so you could be running a 800wrms if you never turned the amp up fully.

Also, sometimes big and powerfull wont give you the best out of your sound system.


as a little off topic in my ibiza i have a crappy 12" sub (350wrms) and an amp supplying it (250wrms) and to be honest with you i have the gain turned up to about 1/4 - 1/3.

Complete rubbish, compare RMS to RMS. Every manufacturer measures 'peak' in a different way. RMS has to be calculated in the same way. Also gain does is not a power selector, it sets the amp to the input signal, so half way could be 1200rms if the signal voltage is right. I have an amp that is measured at 1200wrms, and its a pure sound quality amp not just loud.

Gain settings are dependant on your headunit voltage output. To set the gains properly you need to get it scoped. The vibe sub will take more than 1000rms. Just make sure you dont turn the amp up so high it will distort. Also you might have to uprgarde your vehicles powersupply to cope with the 1200rms demand.

True, but you can safely turn gain down once setup to the input voltage.

im going to a question i asked earlier.... what do you want from your sound system ? clear clean sound ? or massive bass that a whole city will be able to hear.

1200RMS subs are pretty intense, why do you need something like that ? my sub peaks is 250w rms and to be honest it sounds pretty good, haveing something thats nearing the 1200wrms is show level stuff .. isnt it ?

Just because your amp is a 1200wrms amp doesn't mean you use all 1200wrms. But it does mean it'll handle transients better

 

[Adam R]

Complete rubbish, compare RMS to RMS. Every manufacturer measures 'peak' in a different way. RMS has to be calculated in the same way. Also gain does is not a power selector, it sets the amp to the input signal, so half way could be 1200rms if the signal voltage is right. I have an amp that is measured at 1200wrms, and its a pure sound quality amp not just loud.



True, but you can safely turn gain down once setup to the input voltage.



Just because your amp is a 1200wrms amp doesn't mean you use all 1200wrms. But it does mean it'll handle transients better

as i said im no expert at this stuff so trying to pull stuff out my brain is hard sometimes

did not realise that manufacturers measured peak in different ways, thought it was a standard measurment of how much power could be put in to the steaker for a pulse without it blowing. then multiply that number by 0.707 to get the RMS value.

 

[Icecavern]

Nope to measure peak you pick a number between 1 and 100000000000000, halve it, then add 4 and multiply by 4. Then subtract your age, and the age of your oldest child, then multiply by 2 again.

I might have missed the odd step...

RMS is a very specific measurement that is much more standard.

 

[Adam R]

RMS = Root Mean Square.

if you want to find peak power of a speaker then divide the manufacturers rms power.
if you want to find RMS power of a speaker then multiply the manufacturers peak power.

thats very very standard stuff.

even then RMS does not mean much now due to the fact that this does not take in to account the heating effects from an amplifier or speaker.

 

[Icecavern]

The problem is you're assuming there is a relationship between the peak values a company quote and RMS. But there isn't.

 

[Adam R]

The problem is you're assuming there is a relationship between the peak values a company quote and RMS. But there isn't.

well a company has to quote a particular value. and to be honest most good brands dont 'make up' figures. so if you stick to a good brand that isnt cheap. they will / should give you a reputable figure of either rms or peak.

its the ones that say 250 peak power but really have a value of around 80w rms. (mutant is a good example of doing this).

 

[Poverty]

well a company has to quote a particular value. and to be honest most good brands dont 'make up' figures. so if you stick to a good brand that isnt cheap. they will / should give you a reputable figure of either rms or peak.

Not quite true, you will be amazed how much influence company marketing men have over the engineers, and alot of the amps dont actually do the power as stated when independantly tested, and most amps wont make their peak power in the environment that they are intended to be used.

asking for 1200RMS from a standard car battery is a bit stupid if your running this sub at high power. in no expert at this but im sure you would need a few more supporting batteries aswell as a couple of capacitors to help smooth the power delivery.

Well im still running the standard battery without too many issues. the thing you have to watch out for is voltage drop when having the system turned up. If the voltage drops too low most amps will just go into protection mode for a little while untill the voltage is at a decent enough level again.

Power caps just make matters worse. Complete waste of money.

Ideally when running 1200rms you want a upgraded battery in the front, 0 gauge cabling running to the amp, and the big three being done under the hood of the vehicle.Doing this alone would cost roughly £300.

1200RMS subs are pretty intense, why do you need something like that ? my sub peaks is 250w rms and to be honest it sounds pretty good, haveing something thats nearing the 1200wrms is show level stuff .. isnt it ?

1200RMS is more roughly about double what most people are running, however for people who do this as a hobby 1200rms is baby power. Yes at times 1200rms can be a bit overkill, but once you have tasted 1000rms + you wont want to go back to 500rms etc. I used to think my 300rms sub/amp package was good

to be honest, the music I listen to is more Dancey than 3 second 20hz bass so a nice loud punch than a wailing everlasting bass note would be more to my liking.... But then again I'm undecisve in music and listen to everything so sometimes I'd ike my eardrums to bleed

What amp you looking at? I have found the easiest way to get nice thumping is to have 2 lower rated subs than just one big sub. Reasoning behind that being is that there is more cone area, and one big sub usually requires a custom made box before it will sound good.

 

[BigWill]

What amp you looking at? I have found the easiest way to get nice thumping is to have 2 lower rated subs than just one big sub. Reasoning behind that being is that there is more cone area, and one big sub usually requires a custom made box before it will sound good.

I'll give you the specs of both sub and amp ( do remember I'm brand new to this so I'm bound to get it wrong )

The Amp

The Sub

P.S : I cannot believe a small question turned into a nice little debate on RMS etc. How cool is that !
And!! Would it be possible to run two lower power subs off that one amp? ( I'm trying to ask as much as possible, sorry for all the questions)
I have a bit of spending money for the system, but not a massive amount, so buying two subs may be out of the question

 

[Adam R]

Not quite true, you will be amazed how much influence company marketing men have over the engineers, and alot of the amps dont actually do the power as stated when independantly tested, and most amps wont make their peak power in the environment that they are intended to be used.



Well im still running the standard battery without too many issues. the thing you have to watch out for is voltage drop when having the system turned up. If the voltage drops too low most amps will just go into protection mode for a little while untill the voltage is at a decent enough level again.

Power caps just make matters worse. Complete waste of money.

Ideally when running 1200rms you want a upgraded battery in the front, 0 gauge cabling running to the amp, and the big three being done under the hood of the vehicle.Doing this alone would cost roughly £300.



1200RMS is more roughly about double what most people are running, however for people who do this as a hobby 1200rms is baby power. Yes at times 1200rms can be a bit overkill, but once you have tasted 1000rms + you wont want to go back to 500rms etc. I used to think my 300rms sub/amp package was good



What amp you looking at? I have found the easiest way to get nice thumping is to have 2 lower rated subs than just one big sub. Reasoning behind that being is that there is more cone area, and one big sub usually requires a custom made box before it will sound good.

ok cool. any info is good info.

reason why i say good manufacturers is when im talkign about these:
http://www.bostonacoustics.com/car/default.aspx
bose
or focals..

they are the higher end of car audio and they tend not to BS so much about their figures.

 

[Poverty]

I'll give you the specs of both sub and amp ( do remember I'm brand new to this so I'm bound to get it wrong )

The Amp

The Sub

P.S : I cannot believe a small question turned into a nice little debate on RMS etc. How cool is that !
And!! Would it be possible to run two lower power subs off that one amp? ( I'm trying to ask as much as possible, sorry for all the questions)
I have a bit of spending money for the system, but not a massive amount, so buying two subs may be out of the question

Thats the amp I have

What car is it going into? I ask this as then we can get a rough idea on the strength of your vehicles electrics (alternator, battery size)

The sub is ok, nothing special, what seems to be the falvour of the month at the moment is the ascendant audio stuff. Theres a video of 1 fitted in a polo making the panels flex and the doors trying to open lol.

For best value of money however 2nd hand is the way. Just the other day a guy was selling 2 alpine type r subs for £100.