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Speakers Nominal Power handling/Amplifier

My Canton k9  bookshelf speakers have a nominal power handling of 120/200 watts,  SPL of 87db my Technic integrated amp SU-G700 has 70 watts into 8 ohms,140 into 4 ohms.  As an aside, my source is a Marantzcd6006  CD player.
What does Nominal power mean for me in terms of music reproduction in my system? Specifically Will the speakers perform to there potential with my 70 watt amp? I read that nominal power relates to the power your amp should have to drive these speakers. So what am I missing with only 70 watts per channel besides playing louder? what would an amp with 120 to 200 watts give  the speakers that would improve the music? Am I placing my speakers at risk using less power then what the speakers can handle?
I'm a rookie with zip, zero, nada, listening experience to fall back on that is at all relevant so take this with a grain of salt I freakin love the sound detailed(decay of strings and brushes on symbols, fingers plucking guitar strings etc) soundstage( speakers vanish instruments are here there everywhere but not outside of speaker footprint and not real deep front to back )imaging ( instruments have there own place voices are in the center) not harsh or bright but detailed not warm sounding. How much better could it get with a more powerful amp? I can only imagine what a high-end system must sound like!
An observation no audio stores are within 50 miles, unless I count BestBuy so I sadly I must rely on reviews for the most part and what I read here. Regards Scott
scott22
millercarbon's avatar
millercarbon
12,531 posts
 
Forget nominal power, it is a waste and a distraction. What maters is sensitivity. 

At only 87dB those speakers are very inefficient and a bad choice for that reason alone. This is because power requirements increase exponentially with volume. A mere 3dB increase in volume, barely noticeable, requires TWICE the power! A 10 dB increase requires about ten times the power.

So if you had speakers of 95dB or greater they will require only about a tenth as much power. Buy speakers like this and you will eliminate 99% of your amplifier headaches, as you will be happy with as little as 20 to 30 watts. Buy inefficient speakers like you have and now you need 200 to 300 watts. See how quickly the situation gets out of hand?

Tekton Audio Design has a whole line of speakers across a wide range of prices all of them highly efficient and absolute screaming bargains for the money. 

This in your own words is what you like:
I freakin love the sound detailed(decay of strings and brushes on symbols, fingers plucking guitar strings etc) soundstage( speakers vanish instruments are here there everywhere but not outside of speaker footprint and not real deep front to back )imaging ( instruments have there own place voices are in the center) not harsh or bright but detailed not warm sounding.

That's exactly what you'll get with Tekton, and with high enough efficiency you can forget about watts and concentrate on finding amps with those same qualities. A good tube integrated, for example....
lowrider57's avatar
lowrider57
5,396 posts
 
Nominal power is a range provided by the manufacturer
of the average power needed to drive the speaker. I think of it more like a suggestion because sensitivity and impedance of the speaker are the most important specs.

I agree 87dB is a hard to drive load for your amp. I read in a review of the speakers that impedance stays between 4 and 8 ohms across the frequency spectrum. This also is telling that more power will be beneficial. The 4 ohm low impedance and low sensitivity would be better served with a higher power amp; low impedance requires more power, especially in the bass frequencies. As stated above, doubling the amp power would only give you 3dB more gain. So if you like these speakers I would look for a SS amp higher than 140wpc. More power drives the bass with more authority and music will sound fuller, and will reveal more from your components.

The risk you asked about is when using an underpowered amp at a high volume it can cause the amp to clip which produces distortion and possible damage to the drivers in the speakers.


elliottbnewcombjr
5,197 posts
 
I remember the first Canton's I heard, very nice, and beautifully made. Like KEF, they were one of the few inefficient speakers I would have considered having IF I wanted/needed that size.

They are high end 'stand mounted', not bookshelf, they are 15" deep, and have a rear port.

They need plenty of power to reach enough volume, especially to avoid distortion during momentary peaks of power hungry frequencies. IF you use them with a stereo pair of self-powered subs, connected to subtract the low bass requirements from the main amp, then a less powerful amp will work, and, the speakers and it's port will not need to try and make low bass.

I always recommend higher efficiency speakers (if you find some you love) because that means less power is needed, which, buying SS saves money for other equipment/content. AND, importantly, reduces the power enough to try Tubes. In this case, using a stereo pair of self powered subs, reducing the need to significantly amplify low bass, an affordable tube amp could more easily be considered.

It's not just money, the weight, size, heat, all relate to placement options.
scott22 OP
241 posts
 
Millercarbon, Lowrider 57, elliottbnewcombjr,
Thank you for your time and expertise. it was educational and insightful. The speakers could play a bit louder on occasion with certain recordings but on most of my listening, the sound level is fine. My integrated amp has analog meters called "wide range scale peak power meter" and at loud levels the needle at the -10db/10% with occasional spikes to 0db/100% which I assume means I'm at 100% of amps power which is 70 watts (I know the assumption makes asses etc.) I try to avoid any spikes going higher then that for fear of clipping and damaging my speakers and or amp. 
Since I just bought the speakers and amp and I am riveted by the music presentation noted above I won't be selling them anytime soon. I just do not want to damage my gear as it was a financial stretch. 
  • How should I hook up the sub-woofer? Paul McGowan PS Audio in his videos says to run speaker cables from your amps left and right channels to the subs left and right channels but I can't see that relieving the bass signal from the stand-mounted Cantons. There is an instruction in the amps manual that shows an illustration that says "preout right and left" to a sub's Audio in right and left". I assume( here I go again assuming) that by making that connection the amp somehow knows there is a sub and separates the signal to run the low frequencies to the sub and the mids and highs to the Cantons is this correct and would that be the proper set up in my situation?
 
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