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
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....
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.

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.
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?
The only way to relieve the bass from the mains is to use a high pass filter. You can’t do that with an integrated amp if the amp does not have a preamp in and preamp out feature! The sub also needs a preamp in and preamp out feature that goes through a high pass filter!
with occasional spikes to 0db/100%

You’re correct to monitor these spikes in power output. But the fact is that peaks and transients in music are probably going higher than the meters can indicate. Even with a sub you may not be able to push this amp. If the amp is a keeper, then a sub or a sub array is the way to go.

I see that your amp has line out and one preamp output. Using an active powered sub (or two) relieves the amp from using all it's current to power the bass. The subs have internal amps that supplement the main amp.

What subwoofer? Connecting the speaker cables to the sub you are connecting to the high level input it might have a high pass filter. 
Preamp out to subwoofer. HPF and LPF would depend on the individual subwoofer, no?

Adding subwoofers is a work-a-round for the OP since he is married to this amp and speakers. 

The integrated amp has a   "pre out right and left"   it say in it's manual for hooking up a subwoofer however it does not mention the word high pass filter. 
 The Jamo c80 is a powered sub and has 1800 watts. It has the word  "Line"   and beneath the word "Line", it has  four  for lack of a better word interconnect attachments (you know a gold outside cover, white plastic interior and a hole in the center)one is marked  "Left/LFE"  next to it is a similar input marked "Right In". Directly below those two are two similar looking outputs marked "Left" and "Right Out".
  • So can my integrated amp and the sub be connected in a way to relieve the Cantons of their bass responsibilities? 
  • If I can what should I ask for to connect the two channels?
  • I know I'm sounding like a 74 yr old grade schooler but hey you got to start someplace.
Thanks for you help.

I'm still in the honeymoon phase lowrider give me a chance to get bored I've only been married a couple of months so she still looks and sounds sweet lol. 
LFE is for use with a multichannel receiver. You would use a RCA cable from preamp out to RCA LEFT, RIGHT IN on the sub. 
If no high pass filter on sub, only low frequencies will be used from the preamp. 

Check the sub for high Pass, low pass settings.
Canton, Jamo? Wow! "The best and the biggest brand you have never heard of."

I have never heard less than great Canton speaker and I have heard a decent number of them.
It looks like that Jamo does not have a high pass filter. You will have to run the Cantons full range. You can always use an external high pass filter if you want to relieve the bass duties of your amp. Years ago when I had a subwoofer I used this HSU High pass filter and it did the job quite well!!
@scott22, you may want to check out FAQ (manufacturers) and search for 'subwoofer connection type' the two ways to get a signal to the Subwoofer.
One type Pre Out (Low Level) on the Pre Amp Output Panel and a Line Level (Amplified Signal) at the Speaker Cable connection.
Some Subwoofers don't have both types.
Again refer to User Manual  / FAQ / Support by the manufacturers for information and make an effort to understand the specifics.
Since much has already been said, i’ll keep this brief.
First, Millercarbon hits the technical highlights. The exponential power relationship with volume is the primary reason though, why power ratings are overblown. This is because of the necessary corollary: if you did have, say 140 w/ch you’d only get a tiny volume increase. and at 280w a BIG amp) another small increase.
Your speakers will never play all that loud in a large room. But that may not really matter. If the room is small enough, and you listen at modest enough levels, all will be fine.
I am actually more leery about the overall quality of the Technics receiver; especially since inefficient mini monitors tend to be very equipment fussy. That said i know nothing first had about the Cantons.
As to speaker power: simply keep the amp below its level of audible distortion. The only way a modestly powered amp will damage a speaker is if you over-drive it. At the point of clipping (when the signal its the power supply rail and abruptly ends) a large % of high frequency (and awful sounding) distortion is generated, all of which goes to the tiny, fragile tweeter, which gets hot and says "later dude".
Under all other circumstances there is no issue whatsoever, except that, again, a modestly made receiver/integrated amp simply may not have the guts to sound the best.
Hope it works out well, trust your ears.
ps: sorry failed to keep it brief
When you are playing with maximum limits, here are the rough over engineered rules:

1) Use PEAK power handling value of a speaker and the RMS value of your amplifier.
2) An amplifier should typically be rated at an RMS power value at least about 1.5 times the peak handling capability of your speaker. Otherwise clipping may occur.

The general rule of thumb is that an UNDER powered amplifier is much more likely to damage a speaker than the other way round (especially if the amp does not have any clipping protection).

A 10 watt amplifier will EASILY destroy a 200 watt speaker instantly simply by clipping. The reverse is less likely to happen since you will have a bit more time to react to the sounds coming out of an overloaded speaker and turn it down before it does any damage. Clipping can destroy instantly but overpowering takes a little longer which gives you a bit more more time to react to turn your amplifier down.

The moral of the story is not to push the limits of the equipment you have.

OP, People talk about the quality of the watts, too, so there may be additional options besides high sensitivity speakers. https://trueaudiophile.com/phony-watts/
Good discussion and advise Thanks everyone for taking the time and interest to respond. 
 All "expensive" audio products(amps speakers in particular )I would hope have some form of clipping protection. In fact, I would think any manufacturer making expensive gear would do this on behalf of their consumers to do otherwise is to disrespect their consumer's investment. 
 As for me my entry system in my listening space plays reasonably loud on 90% of my music. However, on a poor recording like Led Zeppelin's (CDs) I do find myself pushing the volume up. I never really was concerned with playing loud but protection my gear and maximizing resolution. fyi I'm just 2 meters away from my speakers in a well damped room. 

Your speakers' sensitivity rating means that a mere 1 watt of input will produce 87 dB when measured from 1 meter away under test conditions (in an anechoic space). 87 dB is already pretty loud, but every doubling of distance from the loudspeaker under controlled test conditions results in a 6 dB drop in the speaker output. Let's say you sit 4 meters away, which means you've doubled the 1m distance twice with a theoretical drop-off of 12 dB.  You're still getting 75 dB from a single watt, even with those "inefficient" speakers.   

Now, for some people, with some tastes in music and volume preferences, in some rooms, even 75 dB might be loud enough ... IF we assume we don't need extra headroom for transient increases.  But we cannot assume that.  You might need (or want) an extra 15-20 dB headroom to handle those musical peaks.

Every 3dB increase in speaker output requires double the wattage. Those transient peaks (or just cranking up the volume a bit) might call for 6, 7, or 8 doublings. So if your speakers are nominally 8 ohms, then you might want an amp with a little more juice.  But it really depends on many factors. You're already ahead of the game if you like what you hear and don't notice any clipping. More watts, per se, probably won't widen/deepen the soundstage.  For that, I've found that speaker placement has the biggest impact.  The trade-off is that, if you bring them away from the walls (on stands) to deepen/widen the soundstage, then the bass impact will drop off. To compensate, you might want to try a small powered subwoofer.  Meanwhile, if you are sitting closer to the loudspeakers, that should let you get by with a little less volume.
Hi Scott22!  Will low power damage your speakers?  You do turn the system off at some point in the day, right? Everybody needs to sleep sometimes. Do you worry if your speakers are safe while the system is off? Of course, not! Low power is only a problem if you are trying to play your music louder than the amp can comfortably provide. If you ask it to provide 150 watts, and it can only do 70, it will distort badly. The music will sound bad, grimy or grainy, obviously nasty; that should alert you that there is a problem. But very few civilized people run over 20 watts on a regular basis. Under 5 watts is normal, even with less sensitive speakers. 

You will get all sorts of advice (but you asked for it) on this topic. I have driven Magnepan 1.7i speakers with 9 watt Class Amps and had perfectly lovely music. Could they have played much louder, probably not; but, I didn't ask them to. You will notice that amps are rated for so much power at a certain level of distortion: 9 watts at 10% distortion, 200 watts at 1% distortion, etc. Notice that tube amps are often rated at higher distortion levels than solid state amps. Curious, eh? All this means is that all amps can produce more power that they are rated for, but they won't sound good doing it. You have heard PA amps produce ear splitting howls or buzzes when something went wrong, right? When that kind of thing happens, the tops and bottoms of the amps output flatten off when the amp produces all the power it can. They "max out." The sharp edges of the "clipped" output are full of high frequency energy that can burn out tweeters and even melt the glue that holds the voice coil onto the speaker's inner works. But this never happens under normal listening conditions. If your system sounds wonderful, plays loudly enough, and you are happy and don't need to entertain the entire neighborhood - just sit back and enjoy the music. There are people in the world who insist that toilet paper must be folded just so in order to clean properly. Smile politely at them, thanks them for their advice and do not invite them to dinner. Keep Smiling.
Wow folks this turned into a very good discussion with good advice and insights with every post. Hilde 45 had posted an informative article on watts folks at my level need to read.rego got me to contact the manufacturer's Jamo now owned by Klipsch were accessible and helpful Technics now part of Panasonic not so much actually they suck. 
The pandemic lead me back to listening to music a  positive in these very dark times. You folks have also given me faith in my fellow man. I'm blown away by how willing everyone is to share their insights and time with me sorry if I keep repeating that but it is unique kinda like a fraternity. Well I'm gonna go play Dexter Gordon, and John Coltrain ballads and chill. Be safe be well     
You might find it fun to try a high powered amp, like a Crown class D for only about $330.   You can send it back to Amazon if it does nothing for you.  I have Klipsch Forte speakers which are highly efficient and I really dig a 200 wpc amp compared to a 30 wpc amp.  I don't listen loud at all.  But the dynamics of a high powered amp with even a flamenco guitar player is pretty awesome.