Speaker or Amplifier - which should be more powerful?

[Shivam]

Another simple thing that needs to be cleared is that 'gain' is different from 'power'.

How loud two different integrated amps drive a speaker model is different from how easily these amps drive the drivers present in that speaker !

(This is something that I recently understood after reading up on what Siva from AP had indicated in a telephonic discussion some weeks back.)

 

[jayants]

Everywhere they mentioned that when you drive it loud it will fry the driver. That is true BUT you have take care of that. You will reach the loudness you want within the 50% of the powerful amp. Let me site an example -

- If you use 100W pc amp for a speaker with max handling capacity of 120W
You would reach say x dB at 90% of volume setting and that is your desirable volume. The amp is driven at 90W pc.

- If you use 150W pc amp for the same speaker with max handling capacity of 120W
You would reach the same x dB at 60% of volume setting. The amp is driven at 90W pc.

In the first case, you are pushing the amp to the limit and hence the distortions comes in but not for the 2nd amp at only 60% of the rated power. Why would you again pump up the control when you have already reached your desired volume level! In any case you can't pump it up more than 10% in the low powered amp.

That is my 2 paisa!

So Koushik that means its always desirable to have an AMP with a much higher W compared to the Speaker.

 

[arj]

So Koushik that means its always desirable to have an AMP with a much higher W compared to the Speaker.

Definitely..and with most speakers, unless you are playing them in a open area and not in a room, your ears drums will be destroyed before the speaker

 

[Thad E Ginathom]

your ears drums will be destroyed before the speaker

Take care of your ears and you take care of the equipment too.

But people, especially young people, are foolish sometimes. Why else would they go to concerts where the sound level is at or above that which damages hearing?

 

[skdas]

Great discussion ! It seems for lower volume listening(In Room) we should prefer more powerful Amps at our risk !

 

[manoj.p]

Well, if you want definitive answer on power ratings, better goto the industry standards. Google IEC 268-5 which deals with power ratings of speakers.

Another good reading - from JBL Pro. http://www.jblpro.com/pub/technote/spkpwfaq.pdf

In a gist, IEC 268-5 standard recommends that the speaker be tested continuously for 8 hrs, at a crest value of +6db than the rated power of speaker. That means, the speaker should be able to take 4 times its rated power for 8 hrs. So, a 100 watt rated speaker should be able to take 400 watts power for 8 hrs. So, it is safe to go for amp more than rated power, but stay less than 4 times of that.

 

[skdas]

Thanks ! We are safe !

 

[jls001]

Some reality check: let's say someone wants to buy a decent stereo setup and had decided on a bookshelf and looked at hifimart on this forum. Some of the speaker choices are:

Wharfedale Diamond 10.2 BS (power rating 100W)
SONODYNE SONUS 1501 V3 BS (80W)
BOSTON ACOUSTICS A 25 BS (150W)

It is more than likely that this buyer will look for entry level amplifiers like:

Marantz PM6005: 45W
NAD C 316BEE: 40W
Cambridge Audio Azur 340A: 45W

If one were to go by the accepted wisdom, the ideal amp needed to drive the three speakers listed above would be rated at 150, 120, and 225W, respectively. But amps of these ratings will be in an entirely different league in terms of performance and cost. The next step up (in power rating) from the entry level amps is in the 70-85W class. But that comes at a substantial jump in cost.

My point being: feel free to use lower powered amp with higher rated speakers (I've done that all my audio life). Just don't push your amps beyond its linear operating range. Use it at sane levels (which is probably staying at or below 2 O'Clock at all times) and you will not blow up your speakers.

 

[skdas]

So finally, feel free to use your powered amp with your prefered speaker and enjoy the audio image !

 

[Santy]

Some reality check:
BOSTON ACOUSTICS A 25 BS (150W)

It is more than likely that this buyer will look for entry level amplifiers like:
Marantz PM6005: 45W

My point being: feel free to use lower powered amp with higher rated speakers

Agreed. I do not understand the funda behind these warnings. I think they are referring to extremes possibly.

I bought 2 pairs of Boston A26 (bigger than what you mentioned) and PM5004 (smaller than what you mentioned) for our office library (due to budget constraints) but they played beautifully during testing - even at high volumes. No frying or cooking or burning happened, may be I was fortunate.

 

[pupupuchi28]

Use it at sane levels (which is probably staying at or below 2 O'Clock at all times) and you will not blow up your speakers.

Interesting discussion. How do you identify 2 o'clock in a avr?

I have a 70w rms speaker and 95 w rms amp

 

[spirovious]

I will say like others that marginal more power is better for speakers.The reason can be that when amp sends a signal to a speaker,the driver sends a reverse one to amp during rest and amp has to cancel it to pass next signal to work smoothly.
HowStuffWorks "How Speakers Work"

Also more power can give better fidelity.Not necessary that you play amp at very loud levels so that the speaker gets damaged and eardrums.Also it depends on sensitivity of speaker too.More power also may ensure that you get good output at average listening level as amplifier is yet to distort.Also damping factor can be checked for better speaker control.
Simple calculation for average listening level can be that amplifier power can be more than continuous power handling of speaker,not necessarily more than peak/max power handling.My simple way.

 

[jls001]

How do you identify 2 o'clock in a avr?

No idea. But the same advice applies - operate it below clipping.

 

[elangoas]

Interesting discussion. How do you identify 2 o'clock in a avr?

I have a 70w rms speaker and 95 w rms amp

Roughly 70% of the volume before you hit the maximum volume on your AVR...

 

[manoj.p]

Ideally, the AVR should be run through auto calibration. That sets the correct levels and shows the db accurately. Some AVR's set 0 at 75 db and that becomes the reference. Some do set 75 db at 75 db and it shows correct audio level.

The movies are supposed to have a normal volume at 75 db and dynamic range of 20 db above that. So, normally an AVR should do 75 db and burst of 95 db comfortably. If you have a subwoofer crossed at 80Hz, it helps since most power needed is for low frequencies.

In any case, more power does not mean you should go louder. That just means you have more power when its needed for during loud sounds. This helps in better dynamics. An amp may have lower rated power, but it also does have higher rating for burst power and that serves the purpose.

 

[elangoas]

Ideally, the AVR should be run through auto calibration. That sets the correct levels and shows the db accurately. Some AVR's set 0 at 75 db and that becomes the reference. Some do set 75 db at 75 db and it shows correct audio level.

The movies are supposed to have a normal volume at 75 db and dynamic range of 20 db above that. So, normally an AVR should do 75 db and burst of 95 db comfortably. If you have a subwoofer crossed at 80Hz, it helps since most power needed is for low frequencies.

In any case, more power does not mean you should go louder. That just means you have more power when its needed for during loud sounds. This helps in better dynamics. An amp may have lower rated power, but it also does have higher rating for burst power and that serves the purpose.

What you have said hold's good for the modern AVR which come with room calibration....

What abt old AVR which don't have any room correction?

 

[manoj.p]

Then one should use an SPL meter to set the levels correctly. Without that, the speakers can run at different levels and one wouldn't know true db level. Then the guesstimate is the way to go.

 

[elangoas]

Then one should use an SPL meter to set the levels correctly. Without that, the speakers can run at different levels and one wouldn't know true db level. Then the guesstimate is the way to go.

We had Onkyo HTIB's approx 9 years back... They didn't have any room correction software...We were never aware abt the SPL meter... All we did was set the induvidual speaker db & distance manually with our own discretion...

 

[pupupuchi28]

Roughly 70% of the volume before you hit the maximum volume on your AVR...

Assuming 70% is the 70% of the total reference range, then I'm even more confused on how it will work. In Yamaha RX 371, from -65dbl to -45dbl (I'm refering to reference range), there is no 'significant' change in volume, but the main change starts from -40dbl onwards. It goes till +16dbl. Now given that there is no change in the lower levels, 70% of which range should be considered?

 

[pupupuchi28]

Ideally, the AVR should be run through auto calibration. That sets the correct levels and shows the db accurately. Some AVR's set 0 at 75 db and that becomes the reference. Some do set 75 db at 75 db and it shows correct audio level.

Not sure if this holds good...YPAO on my AVR does not change overall levels per se but at times levels of individual speakers, depending on the reflection on oneside of the speaker. Even then the changes are hardly one or two dbl reference levels ?