Maximum input power

[ifsixwasnin9]

Was looking at this Pioneer bookshelf speaker and only rating it shows is Maximum Input Power = 130W. What exactly is the maker saying with this spec? The closer you approach this power the better performance you'll get from the speaker? And does this spec have any reference to an amp's Max. Dynamic Power or RMS Power rating? (Max. Dynamic Power ratings have high THC ~ 10%.) Seems it would be more helpful to give a Minimum Power Rating (instead of a Maximum) to achieve the designed speaker performance. Kind of a useless spec for the Consumer.

Speaker is very small 5.25" driver, 1" soft-dome tweeter, 6 ohm, 85 dB. Very good review.

Pioneer SP-BS41-LR loudspeaker | Stereophile.com

This Wikipedia Audio Power extract says following: "Chuck McGregor, senior technologist for Eastern Acoustic Works, wrote a guideline for professional audio purchasers...recommended a rule of thumb in which the amplifier's maximum power output rating was twice the loudspeaker's continuous (so-called "RMS") rating, give or take 20%."

Audio power - Wikipedia, the free encyclopedia

 

[j_garcia]

The maker is saying that at 130 of unclipped power is the point where something will most likely physically (electrically) fail, most likely in the crossover.

 

[ifsixwasnin9]

I understand that the Max. Power Rating is the highest wattage that the speaker is designed for but the specs do not state what the Minimum RMS Power is to drive the speakers so the manufacturer really hasn't given much useful information. Or can I calculate the minimum RMS needed using impedance, sensitivity, etc.? Thanks.

 

[jonnythan]

There's really no such thing. In that speaker, at moderate volumes the speaker won't be using more than 1-2 watts.

The speaker's sensitivity gives you an idea of this. At 1 watt you'll get 90 dB of output, which is fairly significant.

 

[gotchaforce]

There's really no such thing. In that speaker, at moderate volumes the speaker won't be using more than 1-2 watts.

The speaker's sensitivity gives you an idea of this. At 1 watt you'll get 90 dB of output, which is fairly significant.

How is that significant?? In a large room that will become 78db (or less) which is very insignificant... and then you deal with exponential power requirements for every 3 db.

 

[fuzz092888]

Because at 1 watt 1 meter = 90db then

1 watt = 90db
2 watts = 93db
4 watts = 96db
8 watts = 99db
16 watts = 102db
32 watts = 105db
64 watts = 108db
128 watts = 111db
256 watts = 114db

Stretch that out to about 4 meters and you get approx. 93db at 32 watts, add in maybe 3db of room gain and you're back up to 96db average which translates into 256 watts for 105db peaks. Since 105db peaks are cinema reference that should be more than enough assuming you have an external amp that can do that, but at 96db give or take at 32 watts, then most any AVR can handle that. Which makes 1 watt = 90db fairly significant.

I should also say that because of room reflections you probably won't even need 32 watts to reach a comfortable listening level in a real room. However when it comes to big peaks, that's when the extra headroom can come in handy, and of course, if you like to listen loud this will also influence things. In the end, for average comfortable listening levels one generally needs far less power than you might think and if you have a speaker that will do 90db at 1 watt 1 meter it becomes significant. What then becomes more of a factor is the rated power handling because of thermal compression and how much power the internal components can actually withstand for sustained periods.

 

[ifsixwasnin9]

What equation did you use for calculating loudness vs. distance (ie. 4m ~ 93dB or 32W)? That's a very helpful explanation.

Anyway, I got the speakers and they are very, very impressive for bookshelf speakers. Running a Yamaha AX596 (100W/channel amp @ 8 ohms, Dynamic Power @ 6 ohm = 170W) w/Carver preamp. The Stereophile review linked above is right on (Reviewer compared these vs. Paradigm Atom v.5 and Wharfedale Diamond 10.1).

They are lacking just a very slight tad of detail. They are very balanced, bass is very impressive and responsive, overall realistic, treble just a touch fatiguing, pleasurable at low volumes. (Not getting 100% effect of electric guitar tones I'm used to, but very close.)

I think my ADS 246ix component (100W, 4 ohm) car speakers have just a little better detail than these Pioneer. And I think my Infinity 7 did, as well (but not the greatest choice at lower volumes).

Now I have to decide if I'll keep the system the way it is or try to experiment with some more equipment. We'll see, but I would recommend these speakers. Thanks for the feedback.

 

[fuzz092888]

Damping of sound level with distance - decibel dB damping calculation calculator distance versus sound reduction drop-off free field loss sound and distance - decrease drop fall in sound over distance versus dB sound at different distances attenuatio

and my numbers were confirmed by EE's here on audioholics.

So if you input 90db for 1 watt 1 meter on the website and then put 4m in for the second distance you get 77.96db or 78db for simplicities sake.

So using our new number of 78db at 1 watt 4m

1 watt = 78db
2 watts = 81db
4 watts = 84db
8 watts = 87db
16 watts = 90db
32 watts = 93db

This is anechoic and doesn't take into account room gain or other room factors, so figure ~3db room gain and you end up with 96db at the listening position for an approximation. Again, actual numbers will differ for room to room.

 

[PENG]

Again, actual numbers will differ for room to room.

Very true, but try telling that to some self proclaimed know it all expert.

 

[Grador]

How is that significant?? In a large room that will become 78db (or less) which is very insignificant... and then you deal with exponential power requirements for every 3 db.

How is that NOT significant? Most people I know keep average volume below that.

 

[fuzz092888]

Very true, but try telling that to some self proclaimed know it all expert.

Haha, I've read enough of "those" conversations to have no desire to get involved