# Underpowered



## Repatilian (Mar 5, 2010)

Hi i was wondering if anybody thinks I should get a new reciever. I have two Cerwin Vega VE-12's and a Klipse Sub-12. The model number of my reciever is RX-V363. I got the receiver in christmas 2008. It was about 235 dollars at best buy. It was the cheapest Yamaha reciever there. I need to know if my reciever is underpowered for my speakers. Thanks


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## recruit (May 9, 2009)

Hello Shane, from looking at the specs of the amp and speakers, I would say you are probably not getting the best out of them with that receiver and more power is always better than less, you potentially may well damage the speakers more so with an under powered amp.


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## chadnliz (Feb 12, 2010)

I dunno if I would exactly say you are underpowered as those CV's are 93db so they are pretty easy to drive but as noted you can do better and far more speakers are blown from too little power or an amp pushed too hard than from a robust amp with gobs of extra power or "headroom" but alos know that increased power doesnt mean much till you double it so 125 or 150w is not going to be a real gain, 200 and watts above is where your really upgrading. Have you ever heard gross distortion or got the feeling the amp was stressed (many audio geeks will use the term "clipping")........thats what happens to an amp pushed to its limits, then the amp looses ability to control the driver and poof you blew something up. I would say if you going from a Home theater side of use your probably ok but if you drive a constant music signal at high levels you may have an issue at some point.


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## lsiberian (Mar 24, 2009)

It is always too much power that blows a surround. Xmax must be exceeded for a driver to blow. There is no way underpowering it will exceed xmax.

Still you can probably do better. If your receiver has external outs check out the Yamaha P2500


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## Jungle Jack (Jul 28, 2009)

Hello,
I never realized that clipping was solely in the lexicon of "geeks". I will have to remember that.
I actually do think that driving an underpowered AVR to high levels can produce distortion which can damage Speakers. Too much power can and will damage Speakers as well.

Repatilian, are you happy with the performance of your HT? If you are, there is no real need to upgrade AVR's. Thankfully, you choose efficient, easy to drive Speakers with your Yamaha and are using a Subwoofer. I would make sure all Speakers are set to Small so your Subwoofer can handle Bass and relieve stress off of the amplifiers in your AVR.
Cheers,
JJ


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## chadnliz (Feb 12, 2010)

lsiberian said:


> It is always too much power that blows a surround. Xmax must be exceeded for a driver to blow. There is no way underpowering it will exceed xmax.
> 
> Still you can probably do better. If your receiver has external outs check out the Yamaha P2500


So your saying there is no way you can blow a speaker if your amp runs out of power? I think you need to research your facts. You a several times more likely to lose a speaker to a amp that runs out of power than you are to an amp with plenty to spare.


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## chadnliz (Feb 12, 2010)

Jungle Jack said:


> Hello,
> I never realized that clipping was solely in the lexicon of "geeks". I will have to remember that.
> I actually do think that driving an underpowered AVR to high levels can produce distortion which can damage Speakers. Too much power can and will damage Speakers as well.
> 
> ...


Yup its in the geek lexicon............glad I could help


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## tonyvdb (Sep 5, 2007)

Distortion is the number one reason for blowing speakers. Clipping an amp can seriously damage a speaker.


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## Repatilian (Mar 5, 2010)

Thanks so much for all the input. It sounds pretty good. I can get distortion from the cerwin vegas if i turn it up real loud. But it's interesting the disadvantages of having a low power amp. I can get the sub too distort with the amp turned up loud and the amp in the sub turned up. Oh if anyones interested in the Klipse sub-12. It's absolutely amazing you will swear your listening to a stereo in a car when you turn the sub-12 up. I think i'm gonna get a better amp just to be on the safe side. Thanks


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## lsiberian (Mar 24, 2009)

chadnliz said:


> So your saying there is no way you can blow a speaker if your amp runs out of power? I think you need to research your facts. You a several times more likely to lose a speaker to a amp that runs out of power than you are to an amp with plenty to spare.





tonyvdb said:


> Distortion is the number one reason for blowing speakers. Clipping an amp can seriously damage a speaker.


It is a fact must exceed xmax to blow a loudspeaker surround. 

Severe Clipping can cause an amp to provide up to twice it's stated ability, but it is still too much power that blows the speaker. Severe Clipping is very noticeable. Distortion is an effect of a speaker blowing and not the cause. This is why special care must be taken with very linear drivers. It is far easier to blow a speaker with an overpowered amp than an unpowered one.


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## tonyvdb (Sep 5, 2007)

lsiberian said:


> Distortion is an effect of a speaker blowing and not the cause.


:huh:
When an underpowered amp hits it max the signwave will flatten on the top and bottom of the peaks this causes sharp changes in driver direction and is distortion. This will blow a speaker much faster and is much more common than you think.
I agree that over powering a speaker will also damage it but is far less likely than using an underpowerd setup.


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## chadnliz (Feb 12, 2010)

lsiberian said:


> It is a fact must exceed xmax to blow a loudspeaker surround.
> 
> Severe Clipping can cause an amp to provide up to twice it's stated ability, but it is still too much power that blows the speaker. Severe Clipping is very noticeable. Distortion is an effect of a speaker blowing and not the cause. This is why special care must be taken with very linear drivers. It is far easier to blow a speaker with an overpowered amp than an unpowered one.


I dont agree and I know many others dont either, a lower powered amp not up to the task is far more likely to blow a driver than a amp with plenty of headroom and control. Both can cause issues and common sense can avoid either being an issue, if it sounds rough then back off and you wont have a problem. The amp along with speakers of 93db efficiency should easily play at moderate levels to even borderline very loud with no problem, add to that proper bass mgmt to sub crossover and the speakers command even less from the recievers internal amp.


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## Repatilian (Mar 5, 2010)

Well i think i'm gonna go for the overpowered amp. Sounds like the best idea. It sounds like leaving a speaker at distortion level for any amount of time is bad. Common sense helps with that. Thanks so much for the information. I have actually blown speakers from turning them up too loud. But i was a kid then. Thanks again.


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## Jungle Jack (Jul 28, 2009)

Hello,
This was originally from Axiom Website and Audioholics reprinted it: 
"How Do Small, Low-Powered Amplifiers Put Speakers at Risk?
Initially, it seems contradictory—how could a low-powered amplifier burn out speakers, when amplifiers of 200 or 400 watts per channel would seem to put speakers at much greater risk? The reason is that a small amplifier of 10 or 20 watts per channel can easily be driven into distortion and “clipping” with even moderately loud playback and dynamic peaks in loudness. The clipping cuts off the waveform and turns the output signal into an almost pure constant DC signal, which can quickly cause the fine wires in the speaker’s voice coils to overheat and melt. A large amplifier outputs clean power to the speakers –distortion-free AC audio signals—that the speaker voice coils will accept on a momentary basis without damage."
Cheers,
JJ


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## chadnliz (Feb 12, 2010)

Jungle Jack said:


> Hello,
> This was originally from Axiom Website and Audioholics reprinted it:
> "How Do Small, Low-Powered Amplifiers Put Speakers at Risk?
> Initially, it seems contradictory—how could a low-powered amplifier burn out speakers, when amplifiers of 200 or 400 watts per channel would seem to put speakers at much greater risk? The reason is that a small amplifier of 10 or 20 watts per channel can easily be driven into distortion and “clipping” with even moderately loud playback and dynamic peaks in loudness. The clipping cuts off the waveform and turns the output signal into an almost pure constant DC signal, which can quickly cause the fine wires in the speaker’s voice coils to overheat and melt. A large amplifier outputs clean power to the speakers –distortion-free AC audio signals—that the speaker voice coils will accept on a momentary basis without damage."
> ...


Thank you!


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## lsiberian (Mar 24, 2009)

Repatilian said:


> Thanks so much for all the input. It sounds pretty good. I can get distortion from the cerwin vegas if i turn it up real loud. But it's interesting the disadvantages of having a low power amp. I can get the sub too distort with the amp turned up loud and the amp in the sub turned up. Oh if anyones interested in the Klipse sub-12. It's absolutely amazing you will swear your listening to a stereo in a car when you turn the sub-12 up. I think i'm gonna get a better amp just to be on the safe side. Thanks


An amp would be a waste of money for you IMO. A Yamaha 363 can easily handle 2-93db sensitive speakers. Do make sure you put your speakers close to the wall. That high of sensitivity usually is designed for close wall placement.

If you want a good amp I'd suggest a Yamaha P2500. Quiet, reliable, lots of power.


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## Repatilian (Mar 5, 2010)

sweet i'll keep the amp i have. I've been hesitant to turn it up loud because i didn't wanna blow my speakers. I'll crank it up today.


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## jackfish (Dec 27, 2006)

The Yamaha RX-V363 is not an "amp", it is an entry level home theater receiver with minimal power capability. It is rated at 100 watts RMS per channel at 1 kHz and 0.9% THD into 8 Ω for the front, center and surround channels. This rating is suspect because of the single frequency signal and relatively high distortion level used. It is also not noted if all channels are being driven to achieve the stated output. If this receiver were tested driving all channels over the full audible frequency range of 20Hz-20kHz and a relatively low distortion of 0.09% or less, it is likely it would barely achieve 50 wpc @ 8 Ohms.


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## chadnliz (Feb 12, 2010)

It should still drive those speakers to reasonable levels.......if it starts to sound bad turn her down, simple enough.


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## lsiberian (Mar 24, 2009)

jackfish said:


> The Yamaha RX-V363 is not an "amp", it is an entry level home theater receiver with minimal power capability. It is rated at 100 watts RMS per channel at 1 kHz and 0.9% THD into 8 Ω for the front, center and surround channels. This rating is suspect because of the single frequency signal and relatively high distortion level used. It is also not noted if all channels are being driven to achieve the stated output. If this receiver were tested driving all channels over the full audible frequency range of 20Hz-20kHz and a relatively low distortion of 0.09% or less, it is likely it would barely achieve 50 wpc @ 8 Ohms.


Driving 2 speakers is easy work for any amp and it is an amplifier and receiver so neither term is inaccurate. 

You would need to test it to make a real observation about it's power anyway.


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## Jungle Jack (Jul 28, 2009)

Hello,
Reptilian, the combination of you having efficient Speakers and a Subwoofer should not but a great deal of stress on the Yamaha that you have. I would definitely make sure to crossover your CV's at 80 Hz to relieve the Yamaha of having to reproduce lower frequencies.

I agree with Chad about gradually increasing your volume and if you reach a point where it sounds compressed or distorted, turn it down. You should be fine. However, if you are frequently reaching a point where either the AVR shuts down or sounds compressed, it might be time to consider a more powerful AVR. Your Room size and preferred listening volume will have a great influence on this.
Cheers,
JJ


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## jackfish (Dec 27, 2006)

lsiberian said:


> Driving 2 speakers is easy work for any amp and it is an amplifier and receiver so neither term is inaccurate.
> 
> You would need to test it to make a real observation about it's power anyway.


Saying "Driving 2 speakers is easy work for any amp" is a generalization that cannot stand in the face of substantial evidence to the contrary. Amp or receiver; Semantics, fine. But referring to the Yamaha RX-V363 as an entry level home theater receiver is certainly more accurate than calling it just an amp.

I don't need to test this particular piece of equipment to make inferences as to its output capability. It is documented to produce 50 watts into 8 Ω at 1 kHz and THD of 0.06% only driving the front channels. So it is sure to produce less than 50 wpc at 20 Hz to 20 kHz and 0.06% THD into 8 Ω with all channels driven. Even with that provided I would think that those speakers would get plenty loud enough with that receiver for my wife to tell me to turn it down.


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## recruit (May 9, 2009)

You will notice a change in sound as it may start to harden up and sound harsh and in some cases distortion can be heard, I remember running a Meridian G55 power amp (100watts x 5) and my front speakers were fine as they were easier to drive (B&W 805S's) than the rears (M&K) but at louder levels distortion was evident through the rears and I quickly backed off the volume...


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## jackfish (Dec 27, 2006)

recruit said:


> You will notice a change in sound as it may start to harden up and sound harsh and in some cases distortion can be heard, I remember running a Meridian G55 power amp (100watts x 5) and my front speakers were fine as they were easier to drive (B&W 805S's) than the rears (M&K) but at louder levels distortion was evident through the rears and I quickly backed off the volume...


And we notice that you moved up to 250 wpc. If one is inclined to back off a desired volume level because of evident distortion it seems to me such a system is deficient and deserves replacement or upgrade.


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## lsiberian (Mar 24, 2009)

jackfish said:


> And we notice that you moved up to 250 wpc. If one is inclined to back off a desired volume level because of evident distortion it seems to me such a system is deficient and deserves replacement or upgrade.


Such distortion isn't necessarily clipping. If one is feeding 100 watts to their speaker chances are the distortion is from driving the speakers to hard.


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## jackfish (Dec 27, 2006)

Whether it is the result of amplifier clipping or speakers not up to the task there is deficiency in the system.


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## lsiberian (Mar 24, 2009)

jackfish said:


> Whether it is the result of amplifier clipping or speakers not up to the task there is deficiency in the system.


It could also be the result of hearing loss. We live in a very loud world so that's always a concern.


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## jackfish (Dec 27, 2006)

lsiberian said:


> It could also be the result of hearing loss. We live in a very loud world so that's always a concern.


True, if indeed our hearing is part of the audio system. Hard to replace or upgrade one's hearing though.

I can relate to that as well as I have high frequency degradation (worse in the left ear) which past high frequency accuity was replaced at some point by tinnitus. My wife makes me keep the SPL meter close the sustained readings of which are not supposed to exceed 85 dB. But I don't think I have ever attributed perceived distortion in an audio system to hearing loss.


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