RMS and Peak Power...

maverickzCar · 23rd January 2008, 17:40

A slightly technical question:

How does RMS Power output and Peak power output affects the Sound Quality with same set of speakers?? I have 6" front components and rear 6x9 on tray and going to change my HU. There are no amps or subwoofer and no plans to add one sometime soon.

The current one, Pioneer 7950 has RMS PO as 22 W and Peak PO as 50 W.
The new one that am aiming for, Alpine 9887 OR Blau MP57, has following specs:

Alpine 9887--
RMS - 18 W
Peak - 50 W

Blau Hamburg MP57--
RMS- 25 W
Peak- 45 W

Does this mean that due to lower Peak power output, Blau MP57 will not be able to drive the current set of speakers that well?
Or, in another case, due to lower RMS PO, Alpine 9887 will face same problem?

Can anyone show some light on importance of these factors (RMS and Peak PO) on the sound quality and how does it affects the overall audio feel (for 2 compos and 2 tray oval speakers and nothing else to drive)...

s0uljah · 23rd January 2008, 18:01

RMS power rating is basically the true measure of the continuous power delivered by the amp/head.

Peak on the other hand is just the amount of power that can be generated for a very very very short negligible time.

A simple test is to run the 50 watts peak from your head and the 50watt RMS from a cheap reliable amp. You will know. On the Head amplification the speakers will start distorting at higher volumes.

Hope this helps! Otherwise the guru's will clear it up for you.

Blue Thunder · 23rd January 2008, 18:06

RMS (Root Mean Square) power is a better indicator of the power output of the amplifier than the Peak music power. Generally, the RMS power value can be used to compare different amps. Do not use Peak music power to compare, since these values can be exaggerated by the manufacturers. You have not mentioned the ratings of the speakers. If the speakers mention 2 power ratings, then make sure that the lower of these values is equal to or greater than the RMS power output of the amp. Hope this helps !

Gill · 23rd January 2008, 18:37

Why only these to HU's Alpine 9887 OR Blau MP57??

maverickzCar · 23rd January 2008, 18:50

Quote:

Originally Posted by Gill

Why only these to HU's Alpine 9887 OR Blau MP57??

Am considering these two because...Alpine 9887 is the *best*, as everyone here says (though frankly I havent listened to it). And Blau MP57, well, its giving me Bluetooth and USB along with a nice display...so it looks like a good VFM....sound quality should be quite good also as Blaupunkt ain't bad...hence shortlisted these two only...but when i checked the power outputs, my mind gave birth to some apprehensions...

DerAlte · 23rd January 2008, 19:51

Quote:

Originally Posted by maverickzCar

Am considering these two because...Alpine 9887 is the *best*, as everyone here says (though frankly I havent listened to it). And Blau MP57, well, its giving me Bluetooth and USB along with a nice display...so it looks like a good VFM....

How much are you getting them for?

Gill · 23rd January 2008, 21:24

Get a HU,taking into consideration your current setup n future upgrades.Listen before you buy....

low_bass_makker · 23rd January 2008, 23:19

Quote:

Originally Posted by maverickzCar

Alpine 9887--
RMS - 18 W
Peak - 50 W

Blau Hamburg MP57--
RMS- 25 W
Peak- 45 W

The alpine will be at 1 % thd and the blau might be at 5 or 10 % thd.

Raxx · 24th January 2008, 07:18

Quote:

Originally Posted by low_bass_makker

The alpine will be at 1 % thd and the blau might be at 5 or 10 % thd.

LBM sir what is 1% thd and what is continuous program power?

navin · 24th January 2008, 10:01

Quote:

Originally Posted by maverickzCar

A slightly technical question

Alpine 9887--
RMS - 18 W
Blau Hamburg MP57--
RMS- 25 W...

1. we love technical questions
2. for the wattage figures RMS is what you should use. Beisdes you need to know % of distortion and freq. range over which the wattage can be delivered.

wattage figures should read as:
10W rms, , 0.1% distortion, 20-20kHz, all 4 channels driven. this would mean that the amp will deliver 10W into each of 4 channels over the entire audible spectrum at distortions low enough to be un-noticeable.

Of course even such figures wont tell you the sonic characteristic of the amp, for that you need that set of SPECIAL measuring devices God gave you (your ears AND what between them).

low_bass_makker · 24th January 2008, 12:05

Quote:

Originally Posted by Raxx

LBM sir what is 1% thd and what is continuous program power?

In few words 1 % thd is 99 % music and 1 % noise.

Blue Thunder · 24th January 2008, 14:31

And in case you are wondering what the acronym stands for, THD is Total Harmonic Distortion. The one-liner by low_bass_makker explains it beautifully.

DRAGONLORD · 24th January 2008, 17:26

You havent mentioned what speakers you have or why you are changing your HU. I have a pio 7950 and it has USB as well as AUX input for mp3/phone.

I suggest you add a good 4 channel amp and you will see a vast difference.

Raxx · 24th January 2008, 20:13

Thanks LBM and Blue Thunder, and what is the difference between continuous program power and RMS?

low_bass_makker · 25th January 2008, 00:15

Quote:

Originally Posted by Raxx

Thanks LBM and Blue Thunder, and what is the difference between continuous program power and RMS?

I would consider them as same.

23rd January 2008, 17:40	#1
maverickzCar BHPian Join Date: Dec 2007 Location: Noida Posts: 55 Thanked: 3 Times	RMS and Peak Power... A slightly technical question: How does RMS Power output and Peak power output affects the Sound Quality with same set of speakers?? I have 6" front components and rear 6x9 on tray and going to change my HU. There are no amps or subwoofer and no plans to add one sometime soon. The current one, Pioneer 7950 has RMS PO as 22 W and Peak PO as 50 W. The new one that am aiming for, Alpine 9887 OR Blau MP57, has following specs: Alpine 9887-- RMS - 18 W Peak - 50 W Blau Hamburg MP57-- RMS- 25 W Peak- 45 W Does this mean that due to lower Peak power output, Blau MP57 will not be able to drive the current set of speakers that well? Or, in another case, due to lower RMS PO, Alpine 9887 will face same problem? Can anyone show some light on importance of these factors (RMS and Peak PO) on the sound quality and how does it affects the overall audio feel (for 2 compos and 2 tray oval speakers and nothing else to drive)...
	() Thanks

23rd January 2008, 18:01	#2
s0uljah Senior - BHPian Join Date: Feb 2006 Location: BLR Posts: 2,222 Thanked: 26 Times View My Garage	RMS power rating is basically the true measure of the continuous power delivered by the amp/head. Peak on the other hand is just the amount of power that can be generated for a very very very short negligible time. A simple test is to run the 50 watts peak from your head and the 50watt RMS from a cheap reliable amp. You will know. On the Head amplification the speakers will start distorting at higher volumes. Hope this helps! Otherwise the guru's will clear it up for you. Last edited by s0uljah : 23rd January 2008 at 18:02. Reason: Also take those head rms/peak ratings with a pinch of salt !!
	() Thanks

23rd January 2008, 18:06	#3
Blue Thunder Senior - BHPian Join Date: Jul 2007 Location: Right here . Posts: 1,657 Thanked: 386 Times View My Garage	RMS (Root Mean Square) power is a better indicator of the power output of the amplifier than the Peak music power. Generally, the RMS power value can be used to compare different amps. Do not use Peak music power to compare, since these values can be exaggerated by the manufacturers. You have not mentioned the ratings of the speakers. If the speakers mention 2 power ratings, then make sure that the lower of these values is equal to or greater than the RMS power output of the amp. Hope this helps !
	() Thanks

23rd January 2008, 18:37	#4
Gill BHPian Join Date: Aug 2007 Location: Mohali Posts: 701 Thanked: 16 Times	Why only these to HU's Alpine 9887 OR Blau MP57??
	() Thanks

23rd January 2008, 21:24	#7
Gill BHPian Join Date: Aug 2007 Location: Mohali Posts: 701 Thanked: 16 Times	Get a HU,taking into consideration your current setup n future upgrades.Listen before you buy....
	() Thanks

24th January 2008, 14:31	#12
Blue Thunder Senior - BHPian Join Date: Jul 2007 Location: Right here . Posts: 1,657 Thanked: 386 Times View My Garage	And in case you are wondering what the acronym stands for, THD is Total Harmonic Distortion. The one-liner by low_bass_makker explains it beautifully.
	() Thanks

24th January 2008, 17:26	#13
DRAGONLORD BHPian Join Date: Oct 2007 Location: bangalore Posts: 85 Thanked: 0 Times	You havent mentioned what speakers you have or why you are changing your HU. I have a pio 7950 and it has USB as well as AUX input for mp3/phone. I suggest you add a good 4 channel amp and you will see a vast difference.
	() Thanks

24th January 2008, 20:13	#14
Raxx BHPian Join Date: Oct 2007 Location: chennai Posts: 56 Thanked: 3 Times	Thanks LBM and Blue Thunder, and what is the difference between continuous program power and RMS?
	() Thanks