General Discussion General discussion about all things car audio, from pioneer, orion, alpine and eclipse.

Matching RMS

Old 09-21-2007, 08:52 AM
  #1  
50 Watt CAFz'r
Thread Starter
iTrader: (1)
 
Join Date: Aug 2007
Posts: 115
Matching RMS

I'm just curious to see how much power everyone usually feeds to their speakers. I always thought it was best to match your amps RMS with the speaker RMS but then I heard that you should be powering your speakers with around 1.5x their recommended RMS.

True? False?

Different for components, 2-way, or 3-way?
n0rad is offline  
Old 09-21-2007, 09:11 AM
  #2  
1000 Watt CAFz'r
iTrader: (10)
 
Sasha's Avatar
 
Join Date: Oct 2005
Posts: 1,418
1.5x all over for me.
Sasha is offline  
Old 09-21-2007, 09:14 AM
  #3  
MTT
--SPECIAL ED--
iTrader: (17)
 
Join Date: Jul 2006
Posts: 1,325
IMO, underpowering them is where the problem lies, as well as INPROPERLY overpowering them.

Underpowering them tends to lead to user abuse where you know they should be louder and we tend to turn the gains up too far and/or the volume and making the amp send a clipped signal dammiging the speakers and shortening the life of the amp from over working.

Over powering them is your best option but you absolutely must set the gains properly, this way you get the maximum performance from both your speakers and your amp.

I don't think there is a real formula as in your 1.5x suggestion, but headroom is always a good thing, you could easily run an amp with 4x the RMS of the speakers but the gains need to be set way down and user abuse of this power kept to a minimum.
MTT is offline  
Old 09-21-2007, 09:33 AM
  #4  
2000 Watt CAFz'r
iTrader: (11)
 
avidedtr's Avatar
 
Join Date: Dec 2006
Posts: 2,544
Smile

Originally Posted by n0rad
I'm just curious to see how much power everyone usually feeds to their speakers. I always thought it was best to match your amps RMS with the speaker RMS but then I heard that you should be powering your speakers with around 1.5x their recommended RMS.

True? False?

Different for components, 2-way, or 3-way?
True

my subs are seeing 600 and they ask for 300(150rms each) but gains are at the lowest and NF control is at 0.

I usually match the amp with a 20-50 more then the rms ratings. The key is not to go under the RMS ratings and use atleast a 4Volt+ preout head unit!

This formula has worked for me for years and still hasn't failed yet!
avidedtr is offline  
Old 09-21-2007, 10:15 AM
  #5  
50 Watt CAFz'r
Thread Starter
iTrader: (1)
 
Join Date: Aug 2007
Posts: 115
That makes sense.

The amp I think I am going to use is JBL's GTO 75.4II which is rated at 104W RMS x 4 @ 4 ohms. My rear speakers are rated at 100W RMS and I haven't decided on a front setup but most likely the speakers I am buying are rated at 90W RMS.

What do you guys think?
n0rad is offline  
Old 09-21-2007, 10:17 AM
  #6  
MTT
--SPECIAL ED--
iTrader: (17)
 
Join Date: Jul 2006
Posts: 1,325
Originally Posted by n0rad
That makes sense.

The amp I think I am going to use is JBL's GTO 75.4II which is rated at 104W RMS x 4 @ 4 ohms. My rear speakers are rated at 100W RMS and I haven't decided on a front setup but most likely the speakers I am buying are rated at 90W RMS.

What do you guys think?
it will power those nicely.
MTT is offline  
Old 09-21-2007, 10:25 AM
  #7  
2000 Watt CAFz'r
iTrader: (11)
 
avidedtr's Avatar
 
Join Date: Dec 2006
Posts: 2,544
Originally Posted by MTT
it will power those nicely.
I agree↑
avidedtr is offline  
Old 09-21-2007, 11:02 AM
  #8  
Moderator

iTrader: (2)
 
wasted911's Avatar
 
Join Date: Nov 2005
Posts: 1,285
I'm feeding 180 to each speaker.. and they're rated at... I dont even know. But they do like the power.
wasted911 is offline  
Old 09-21-2007, 11:43 AM
  #9  
50 Watt CAFz'r
iTrader: (1)
 
Ligeia's Avatar
 
Join Date: Mar 2007
Posts: 190
What is the difference between overpowering something the right way and overpowering something the wrong way?

I mean, if you turn the gain way down on a 1kW amplifier, the speaker isn't seeing 1kW and you're not "overpowering" the speaker. This thread reads as if we're assuming that using a 1kW amplifier will produce 1kW at all times, and using a 500W amplifier will produce 500W at all times. Neither of those is true. If you have the power necessary to reach a given level of output without inducing clipping, then it should be good enough. Matching your amplifier's RMS rating to the speaker's RMS rating really isn't that big of a concern...to me, anyways.

Last edited by Ligeia; 09-21-2007 at 11:51 AM.
Ligeia is offline  
Old 09-21-2007, 12:03 PM
  #10  
MTT
--SPECIAL ED--
iTrader: (17)
 
Join Date: Jul 2006
Posts: 1,325
Originally Posted by Ligeia
What is the difference between overpowering something the right way and overpowering something the wrong way?

I mean, if you turn the gain way down on a 1kW amplifier, the speaker isn't seeing 1kW and you're not "overpowering" the speaker. This thread reads as if we're assuming that using a 1kW amplifier will produce 1kW at all times, and using a 500W amplifier will produce 500W at all times. Neither of those is true. If you have the power necessary to reach a given level of output without inducing clipping, then it should be good enough. Matching your amplifier's RMS rating to the speaker's RMS rating really isn't that big of a concern...to me, anyways.
You'll have to forgive my misuse of the term "Overpowering them"....but i did explain myself with the "headroom" comment....

...I just reread the whole post and I'm not getting out of it what you are .....I think we're all saying the same thing, your grasp of the English language is just Superior to mine
MTT is offline  

Thread Tools
Search this Thread
Quick Reply: Matching RMS


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.