Hi all ...
A quick question .. might be a dump question .. hope u all dun mind ...

If my speaker is stating that the max power handling is 100w, Nominal impedance = 8ohm, can i use an amplifier that is having 125W per channel to drive this? Since the power delivered by the amp is higher than the power the speaker can handle, will it damage the speaker?

Thanks and hope to hear from you all ...

Regards,
JS

Yes you can, in fact its better to have a stronger amp. Just dont crank too loud and your speaker wont pecah.

what is the advantage of having higher power amp with lower power speaker ?

Some article did provide the following guideline:
"In general, the amplifier power needs to be larger than the speaker's rated power. This is because an amplifier only delivers its rated output power with sinewave signal, and delivers much less with a real signal with dynamics. As ageneral guideline, it is recommended to use an amplifier delivering 50% more power than the speaker's average ("RMS") power. For example, for a speaker with 450W average power, an amplifier with an output of 700W may be used. If a small amplifier is used, sufficient level will not be reached, nor the perception that it is attained, so the signal will tend to be clipped to compensate, thus endangering the integrity of the speaker."

But assuming an amplier is claiming that it will be able to deliver constant 125w and the max power that the speaker can handle is 100w, do you think this works fine?

Before we go further, can you let us know what the speaker and the amp is. The reason I ask,is if it is an AVR and you are driving more than 2 channels, chances are it will be much lower output.

Also is the 125w RMS or peak?

The speaker that i am using is the B&W DM602, rated as max power handling = 100W (RMS) and Norminal Impendence = 8ohm.
I am trying to get the Onkyo TX-SR706 or 606, which is having a 7*125w (RMS), so i am just worried that it may not match. A bit lazy to bring this heavy stuff to the shop .. hence ask some of you guys here and hopefully can get some good advise

jsng,

Are you planning to use the Onkyo for 2 channel music or for 7 channel movies? Or is it for both?

For both
but mainly for movie ..

The B&W DM602 shd be ok up till 120W I believe. Also the Onkyo definately does less than that shd u drive more speakers. Unless u r playing 2 channel speakers at high volumes (and distortion), u shd be ok. However, pls check with someone at the store.

Add: Again, it is safer if the amplifier max is within the speaker range for safety reasons. If u overdrive the speakers, ie, high volumes, then the risk is higher. Check the power rating of the amp if only 2 channels are driven at 8ohms, it would be higher, so don't blast 2 channel. If more channels, then shd be more than ok.

This post has been edited by anfieldude: Oct 21 2009, 04:02 PM

Quick answer...

Sure can, no probs..

muahahaha u r quick as well
Thanks anyway ...

As long as the max RMS Watt of the speaker and the power amp is not a big difference there should be no probs..

But check also the power amp impedance handling.

The problem comes when you have a 20W power amp and powering a 200W speaker at full blast..
Since the power amp has so little watts, what comes out of it is distortion rather than clean signals.
Distortion breaks speakers

or

Using a 200W poweramp to a 20W speaker at full blast...

Err... How about a pair of ancient JBL northridge series speaker with Max power 175 watt @ 8ohm impedence pair with Onkyo 674.

Will it cause clipping with 5 channel?

Bro care to elaborate a bit between RMS and peak power. For example my RF52 is 100W RMS / 400W peak. What's the difference? Thanks.

OK .... thanks all .. i believe i got the answer now :-)
Again .. thanks ..

I believe RMS is constant power, whereas peak power is instantaneous power (spikes). Thus most of the time it can handle up till 100W but it allows for maybe microseconds of very high power fed to it (high dB scenes).

The Onkyo 674 is rated at?

I doubt it can cause clipping.

cool. thanks for the info

Below is he info I get from Onkyo website:
Power Output
Front L/R .......................... 185 W + 185 W (6 Ω, 1 kHz, 1 channel driven, JEITA)
Center ............................... 185 W (6 Ω, 1 kHz, 1 channel driven, JEITA)
Surround L/R.................... 185 W + 185 W (6 Ω, 1 kHz, 1 channel driven, JEITA)
Surround Back L/R ........... 185 W + 185 W (6 Ω, 1 kHz, 1 channel driven, JEITA)
Dynamic Power................................... 225 W + 225 W (3 Ω, Front)
170 W + 170 W (4 Ω, Front)
105 W + 105 W (8 Ω, Front)

Based on this info, there shd be no problems.

let's work backwards for a bit...

you want your system to do 85db SPL (that is reference level, normal listening is usually some way below that, like 75db SPL)

so 85db SPL output, and you are sitting what, 3m away from the front.

now, JBL Northridges are fairly efficient, about 90db/w/m

then we plug these figures into this calculator (http://www.crownaudio.com/apps_htm/designt...ect-pwr-req.htm) and give it 3db headroom,

it turns out you only need about 6W steady output, really.

Even if you up the headroom to 9db (meaning when there's a explosion or something, it goes to 94db SPL) you will only need 23W per channel.

So the Onkyo, rating at 185 W (6Ω, 1 kHz, 1 channel driven, JEITA) probably translates to max 60W 6Ω 20Hz - 20kHz all channels driven has more than enough power.

This post has been edited by SiriuslyCold: Oct 23 2009, 09:50 AM

Excellent explanation...Most speakers that are of high efficiency are easy to drive...

Actually, a lot of japanese AVRs overstate their power quite a bit.

Its more like testing with limited parameters and publishing the results of that. I'm sure Onkyo and JEITA can verify 185W per channel but the fine print says its 1kHz one channel driven.

so, feed a 1kHz signal to one channel of the amp and test output, sure can get 185W. But a video / music programme is never a steady 1kHz, and never 1 channel only.

So its 20Hz - 20kHz to 8 channels ... nobody publishes those results.

Sirius and anfiel, thanks for the explanation.

YOu sure had brighten up my doubt.

Yup, I had search high and low thru the web, never found anyone publish the power rating of 8ohm impedence with all channel driven for Onkyo older model...

Onkyo seems likes to play trick with their rating figure to the novice user

This post has been edited by Vinceyang: Oct 23 2009, 12:17 PM

to be fair, all manufacturers do this with the AV receivers. Partly because consumers WHAT to see a lot of power output even when they don't really need it. For example, people have had good sound from stereo integrated amplifiers putting out only 20W or 40W maciimum

(I also forgot to mention that into 8Ω the output will be even lower..

That's a useful tool you found. Thanks.

Just one note about what you wrote on reference level. The 75 dB level for reference is just average volume. U need to also factor in the power requirements for the peaks, which can reach +30 dB above the average volume (up to 105 dB per Dolby standards).

So using the same calculator, you will need 285W for peaks (assuming you listen at reference level).

105db is for the LFE channel, IIRC so you need a sub with >300W (if all other things remain the same)

The subwoofer normally has its out power amp to cater for this. So 85dB calculation for front speakers are more than loud enuf.

For music, the recordings do not need the +30dB headroom. Its mainly a movie thingy (Dolby IIRC)

Actually LFE channel peak is 115dB (+10 more than the mains).

---

Added on October 23, 2009, 7:58 pmYeah, the +30dB headroom is more for movies.

This post has been edited by jchong: Oct 23 2009, 07:58 PM

to all sifu...i have a noobie question :-

Me now using Pioneer A400x amplifier with this spec

Power Rating : 60 Watts per channel (8 Ohms)
Total Harmonic Distortion: 0.03% at 20Hz-20kHz
Frequency Response: 5Hz-100 kHz (CD, Tuner, Aux, Tape)
Signal to Noise: 88 db
Power Consumption: 520 watts
Dimensions (WxDxH) : 42 x 35.2 x 12.6 cm
Weight: 8.0 kg
and i would like to match with the speaker that TS using right now
B&W DM602, Is it should be ok? I try to understand the meaning of all discussion but i seriously i not understand still..

I use to worry about this then but now my tube amp is only 15wpc and driving my 125w rms speaker without any problem but I usually never listen past 10 o'clock on the dial.

Basic rule is if you only listen at normal to moderate volume you dont have to worry about this stuff

yup...that is so truth but the problem is i using mixer tu turn the volume up n down because i am mixing song. should be no problem?

no idea bro. im a simple guy. i dont use blender

LOL

On another note, our friend Saprozeldo MIA. Kiam also hilang. Wonder what system that they are using now

talked to sapro a while back. still using same stuff

What should be the appropriate headroom value for music?