How do I know if I need an amp?

[FNG212]

Theres a saying "The blind man doesn't know what he's not seeing". That being said, how do I know if I need an amp? Or for that matter if my speakers sound the way they are supposed to? When I watch movies I think things sound really good, I enjoy the experience. I read a lot on here about all the amps people have and wonder why 200W per channel (Emotiva XPA-5 just as an example) is necessary? I am not opposed to it, just curious. My Yamaha receiver delivers 75wpc (probably less I know) but it goes plenty loud without distorting (as far as I can tell).

So my original question: What advantages does 200wpc give and how do I know if I need that much more power?

 

[Lordoftherings]

Theres a saying "The blind man doesn't know what he's not seeing". That being said, how do I know if I need an amp? Or for that matter if my speakers sound the way they are supposed to? When I watch movies I think things sound really good, I enjoy the experience. I read a lot on here about all the amps people have and wonder why 200W per channel (Emotiva XPA-5 just as an example) is necessary? I am not opposed to it, just curious. My Yamaha receiver delivers 75wpc (probably less I know) but it goes plenty loud without distorting (as far as I can tell).

So my original question: What advantages does 200wpc give and how do I know if I need that much more power?

If you are using your Yamaha receiver (75 watts per channel, perhaps the HTR-5830 or the RX-V440?), and that all your speakers are true 8-ohm loads, plus a sensitivity of about 90db, plus your room is of average size (18 feet by 14 feet), and that you are not listening at loud volume levels, you are probably just perfectly fine. And if it already sounds good to you, why bother.

But the real proof is the pudding, such as trying yourself in your own home with a more powerful amp to see if you notice a worthwhile investment.
Who knows, your speakers might enjoy that extra shot of adrenaline, and provides you with some additional singing.

So, the moral of the story; don't ask, just try for yourself with your own equipment and room. That is the best way to truly find out.

Bob

 

[mtrycrafts]

Theres a saying "The blind man doesn't know what he's not seeing". That being said, how do I know if I need an amp? Or for that matter if my speakers sound the way they are supposed to? When I watch movies I think things sound really good, I enjoy the experience. I read a lot on here about all the amps people have and wonder why 200W per channel (Emotiva XPA-5 just as an example) is necessary? I am not opposed to it, just curious. My Yamaha receiver delivers 75wpc (probably less I know) but it goes plenty loud without distorting (as far as I can tell).

So my original question: What advantages does 200wpc give and how do I know if I need that much more power?

So, as far as you can tell, there is no audible distortion. Then, there is nothing to worry about; the receiver you have is capable of satisfying.

The problem comes in when you have a demanding speaker load, not very sensitive, large room and listening from afar with loud audio. Speakers can distort that becomes audible and annoying. Then, perhaps a more capable amp may be in order?

As to that Yam power, it is 75 watts and most likely it is capable of that into 2 channels at the same instance. Movie soundtracks, while seeming to be loud in all the channels, it is not at the same instants in time so the amp is not driven to power demands to all channels at the same time.

Besides, to properly compare yours with a more powerful amp would need controlled conditions and proper level matching to know for sure

 

[CraigV]

Does your receiver even have pre-amp outputs that would allow you to try an outboard amp?

 

[FNG212]

Honestly I dont know what pre-amp outputs look like. There are binding posts for 5 channels, that seems to be the only "outs" as far as audio goes.

It's a Yammy HTR-5550, probably about 5-6 years old. It has a lot of different audio listening modes; the one I've found to work best for movies is the "70mm Theater - General" option with Dolby Digital turned on (IIRC, there may be more things turned on at that point).

 

[croseiv]

Honestly I dont know what pre-amp outputs look like. There are binding posts for 5 channels, that seems to be the only "outs" as far as audio goes.

It's a Yammy HTR-5550, probably about 5-6 years old. It has a lot of different audio listening modes; the one I've found to work best for movies is the "70mm Theater - General" option with Dolby Digital turned on (IIRC, there may be more things turned on at that point).

In order to run an external amp, you'll need to have pre-outs (on the rear panel you'll see them labeled as such). You'll have to peek behind the receiver to see what it has or read the manual...If you have them then you can connect using RCA cables to an amplifier.

 

[Lordoftherings]

Your Yamaha HTR-5550 does not have preouts anyway.

Plus your Klipsch speakers are super sensitive.

You don't need an Emotiva XPA-5 multichannel amp definitively.

Bob

 

[CraigV]

Hardly anyone really “needs” a beefier amp, but there are advantages, more headroom for one. When I went from a 105 WPC to the XPA-5 with 230 WPC there was better focus, tighter bass and the soundstage solidified noticeably. Will everyone be able to appreciate the differences - no, but it can’t hurt to try (except in the case of the OP who has no means to send the signal to the amp).

 

[Adam]

When I watch movies I think things sound really good, I enjoy the experience.

I think that answers your question. If you have no complaints, then there's no reason to think about spending money to get an amp. Don't get one just because other people have one.

 

[josko]

I think many of us wonder just how much better our HT would sound with a bigger amp. In my case, (Yamaha 661 driving 4 Polk LSi9's and an LSiC), I know the speakers are difficult to drive, but virtually all of my listening is at -30 to -20 gain , so I figure I'm putting out a max of 1W per speaker. Even at 4 Ohms, the receiver should be able to deliver that, no?
I guess my question is whether music peak levels exceed 20 dB(above RMS), so the amp's clipping or distorting at signal peaks even at -20 dB gain. The other issue is whether it's distorting appreciably at -20 dB.

If it's not clipping at music peaks and distortion (THD or IM) is low at listening levels, is it reasonable to assume the listening experience would not be enhanced by a better amplifier?

 

[Lordoftherings]

Some logical thinking.

I think many of us wonder just how much better our HT would sound with a bigger amp. In my case, (Yamaha 661 driving 4 Polk LSi9's and an LSiC), I know the speakers are difficult to drive, but virtually all of my listening is at -30 to -20 gain , so I figure I'm putting out a max of 1W per speaker. Even at 4 Ohms, the receiver should be able to deliver that, no?
I guess my question is whether music peak levels exceed 20 dB(above RMS), so the amp's clipping or distorting at signal peaks even at -20 dB gain. The other issue is whether it's distorting appreciably at -20 dB.

If it's not clipping at music peaks and distortion (THD or IM) is low at listening levels, is it reasonable to assume the listening experience would not be enhanced by a better amplifier?

Hi Josko,

If you really wonder, just get a bigger and newer receiver.

A receiver like yours (Yamaha RX-V661) is not designed to handle 4-ohm loads with all channels driven. It might be fine in 2-channel stereo mode, but that will be about it. And at the volume levels that you mentioned (-30 to -20db), it should pose no problem at all. And with your Polk LSi9 and LSiC speakers, even rated with a nominal impedance of 4-ohms and 88db sensitivity, it should also be fine. Remember too, that all your Polk models have only two 5.25" drivers per speaker (one for the midrange, and one for the woofer). And of course with a 1" tweeter. Also they are quite small for their size. So they don't required a big amp to move air from their small drivers in these smaller speaker box sizes. I'm not saying that they are of the very small sizes, but they are not that big at all either. And I bet that they sound pretty good too, they are not cheap speakers by any mean. To the contrary, they seem very well build, solid and quite expensive too.
And I think your 661 is a good match for them.

I'm not sure if you will gain anything at all with an external amp like an Emotiva UPA-7. Perhaps with the Emotiva XPA-5, but not by very much at the listening volume that you are listening.

Instead of adding an external amp for more power and that will cost you an additional $800 (the XPA-5), why not getting a more powerful receiver like the Yamaha RX-V1700 or RX-V2600 in the first place at that time? That will have cost you an additional $600 approximatively (street price). It would have not only cost you less, but you would have also gain more processing power, more features, more DSP audio modes, more connections, better Dacs and better 4-ohm loads handling.

In conclusion, I'll say that your Yamaha RX-V661 is just fine for your nice Polk peakers and your reasonable listening levels.

Hope that helps to clarify some wondering of yours.

Regards,

Bob

 

[MichaelJHuman]

I think many of us wonder just how much better our HT would sound with a bigger amp. In my case, (Yamaha 661 driving 4 Polk LSi9's and an LSiC), I know the speakers are difficult to drive, but virtually all of my listening is at -30 to -20 gain , so I figure I'm putting out a max of 1W per speaker. Even at 4 Ohms, the receiver should be able to deliver that, no?
I guess my question is whether music peak levels exceed 20 dB(above RMS), so the amp's clipping or distorting at signal peaks even at -20 dB gain. The other issue is whether it's distorting appreciably at -20 dB.

If it's not clipping at music peaks and distortion (THD or IM) is low at listening levels, is it reasonable to assume the listening experience would not be enhanced by a better amplifier?

Note though, while you may use less than 1 watt average, peaks can be more demanding.

For music, a 15 dB difference between average and peak levels is a good number to assume. Movies may be more, but I have no easy way to measure movies ( I measured music by writing a program to analyze WAV files.)

I took a reading with a voltmeter and with one song I saw average levels around 2 to 3 volts are at -10 dB on the volume readout. I saw that level spike to as high as 40 volts a few times. While your power supply's filter caps might be able to handle some of that load, you can still see where your needs could be higher than expected due to peaks in your source material.

That being said, for movies, I have never run out of power at any level I care to listen to. Even if there was some clipping, I did not notice it.

For music, it's always seemed to me like more power would be helpful. You know how you turn it up a bit, and the quality level sometimes seems to go down. Someone once told me that's probably causes by audible clipping, and I would be able to see it with an oscilloscope.

Just to throw some numbers out, let's say you are 4 meters from your speakers. You will lose 12 dB right there. Add back in 3 dB for multiple speakers ( maybe more, but I once measured 3 dB, so I use that.)

Assume 90 dB sensitive speakers, and assume an average listening level of 85 dB. To achieve 85 dB with the above mentioned conditions, you need about 2 watts average to your speakers, which is of course quite low. If your movie had peaks 20 dB over average level, you would need 100 times that power. Maybe your power supply caps can meet those temporary demands, and maybe not.

I don't think most people really need more power. But if you have money, and it's practical for your setup to add some external amplification, it could help reduce the chance of clipping.

 

[GrandLotus]

Hardly anyone really “needs” a beefier amp, but there are advantages, more headroom for one. When I went from a 105 WPC to the XPA-5 with 230 WPC there was better focus, tighter bass and the soundstage solidified noticeably. Will everyone be able to appreciate the differences - no, but it can’t hurt to try (except in the case of the OP who has no means to send the signal to the amp).

Is their a point for someone (like myself) to install an amp onto front speakers that will become two time more powerfull than the surrounds?
I have a Mic that sets the sound where I chose, but I could always raise the level of power. I have heard that when your speakers are underpowered the lower wattage could be dangerous for them. Yes No?

 

[MichaelJHuman]

Is their a point for someone (like myself) to install an amp onto front speakers that will become two time more powerfull than the surrounds?
I have a Mic that sets the sound where I chose, but I could always raise the level of power. I have heard that when your speakers are underpowered the lower wattage could be dangerous for them. Yes No?

Speakers are terribly inefficient, with most of the power being converted to heat. And heat can kill voice coils.

Clipping can result in excess heat, especially to the tweeter which could damage or destroy the voice coil. There are some good articles on the topic. The experts will tell you it's due to the compression which results from clipping - compression increases your average voltage levels to the voice coils significantly.

I have only managed to blow one speaker at home, and that was at a party when I pushed the volume to very high levels as the receiver was downstairs.

So more power can be helpful to avoid clipping. I would think most people don't listen at levels high enough to cause problems. Parties are (anecdotally) a speaker killer as alcohol sometimes seems to require loud music, and the warning signs of distortion get ignored. And that's music. I have yet to hear of someone blowing a speaker with movies, which don't have the same continous levels - I am sure some have managed it though.

 

[mtrycrafts]

Note though, while you may use less than 1 watt average, peaks can be more demanding.

For music, a 15 dB difference between average and peak levels is a good number to assume. Movies may be more, but I have no easy way to measure movies ( I measured music by writing a program to analyze WAV files.)

I took a reading with a voltmeter and with one song I saw average levels around 2 to 3 volts are at -10 dB on the volume readout. I saw that level spike to as high as 40 volts a few times. While your power supply's filter caps might be able to handle some of that load, you can still see where your needs could be higher than expected due to peaks in your source material.

That being said, for movies, I have never run out of power at any level I care to listen to. Even if there was some clipping, I did not notice it.

For music, it's always seemed to me like more power would be helpful. You know how you turn it up a bit, and the quality level sometimes seems to go down. Someone once told me that's probably causes by audible clipping, and I would be able to see it with an oscilloscope.

Just to throw some numbers out, let's say you are 4 meters from your speakers. You will lose 12 dB right there. Add back in 3 dB for multiple speakers ( maybe more, but I once measured 3 dB, so I use that.)

Assume 90 dB sensitive speakers, and assume an average listening level of 85 dB. To achieve 85 dB with the above mentioned conditions, you need about 2 watts average to your speakers, which is of course quite low. If your movie had peaks 20 dB over average level, you would need 100 times that power. Maybe your power supply caps can meet those temporary demands, and maybe not.

I don't think most people really need more power. But if you have money, and it's practical for your setup to add some external amplification, it could help reduce the chance of clipping.

This link has some good info and calculations on the losses per distance under the sound and hearing:
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

In a closed room, not an auditorium size, that loss for doubling distance is much less than 6dB per doubling. that 6 dB applies for outdoors and large rooms, auditorium sized ones.

 

[PENG]

This link has some good info and calculations on the losses per distance under the sound and hearing:
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

In a closed room, not an auditorium size, that loss for doubling distance is much less than 6dB per doubling. that 6 dB applies for outdoors and large rooms, auditorium sized ones.

Too bad people tend to forget the difference between "in a room" and "in open field".

 

[PENG]

I took a reading with a voltmeter and with one song I saw average levels around 2 to 3 volts are at -10 dB on the volume readout. I saw that level spike to as high as 40 volts a few times.

I had done similar experiment and did not see that kind of spike, may be half that, using the following:

Wilson AudioPhile Definitive Recording
Winds of War And Peace
Liberty Fanfare from 3:50 to end of track

Also used:

Track one of Telarc's Copland Appalachian Spring at around 2m30s to 2m:50s and also one of Telarc's 1812.

SPL at the time was around 91 to 105 dB.

Obviouis my Hioki 3282 is not a scope but it does capture peaks quite well and has a reasonable frequency response range.

Would you mind telling me what "song" you used to get that 40V spike?

Thanks in advance.

 

[MichaelJHuman]

Certainly. I used Closer by NIN because it has some loud drum hits in it. In fact, they are so demanding of power, I can see the extra power draw on a Kill A Watt power meter. The peaks on the Kill A Watt fluctuate with the drum hits.

Thanks for the info on loss from distance. I will take a look at it. I have been looking for more info on that topic.

 

[PENG]

Certainly. I used Closer by NIN because it has some loud drum hits in it. In fact, they are so demanding of power, I can see the extra power draw on a Kill A Watt power meter. The peaks on the Kill A Watt fluctuate with the drum hits.

Bass drums and Timpani, they are demanding for sure.

 

[mtrycrafts]

Too bad people tend to forget the difference between "in a room" and "in open field".

Hey, they both starts with 'in'
Wonder over to the members system