Thinking of buying my first amplifier

M

mortizar

Audiophyte
I am thinking of buying my first amplifier so have read over specs, but I have no real experience with amplifiers except what I have read online. So I would like some advice/opinions on the ones I am considering.



The D-Sonic amps seem to have a lot of power for the price, but no one comes anywhere near their power listings. So I am curious if the power ratings their listing are accurate. Both the NAD and Wyred 4 Sound seem like good amps, just on the upper end of what I would be willing to spend, plus their ugly. The Emotiva seems like a good deal and look cool. However, the specs page seems to suggest that it can run all channels at the listed wattage at the same time; not sure if that’s a big issue or not.
 
ski2xblack

ski2xblack

Audioholic Samurai
First, have you determined if you actually need more powerful amplification than you have now? Audioholics recently published a helpful article that goes through a methodical process to help you determine the answer: linky

And an article on the games played with wattage ratings.

No particular brand allegiance or personal experience with your list. You may want to add the Monoprice amps (by ATI).
 
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mtrycrafts

mtrycrafts

Seriously, I have no life.
I am thinking of buying my first amplifier so have read over specs, but I have no real experience with amplifiers except what I have read online. So I would like some advice/opinions on the ones I am considering.



The D-Sonic amps seem to have a lot of power for the price, but no one comes anywhere near their power listings. So I am curious if the power ratings their listing are accurate. Both the NAD and Wyred 4 Sound seem like good amps, just on the upper end of what I would be willing to spend, plus their ugly. The Emotiva seems like a good deal and look cool. However, the specs page seems to suggest that it can run all channels at the listed wattage at the same time; not sure if that’s a big issue or not.
Welcome to AH.

Firstly, what are your needs, what speakers you are driving and how many, room size, listening levels you want.
If you have a sound system, is there an issue that you need dedicated amps? Shortcomings?
 
lovinthehd

lovinthehd

Audioholic Jedi
, but I have no real experience with amplifiers except what I have read online.
Might want to expand on this, lots of information out there that's meaningless when it comes to amps
 
M

mortizar

Audiophyte
First, have you determined if you actually need more powerful amplification than you have now?
The simple answer to this is no, not with my current listening environment and equipment. That said, I started looking at amplifiers because of my desire to upgrade to UHD, which would require me to upgrade my receiver. My exploration into upgrading my receiver has made me feel that separates are the better route, so that amplification and pre-amplification are separate purchases. Also so that each subsequent upgrade I am not repurchasing amplification, as I would with a receiver.


Welcome to AH.

Firstly, what are your needs, what speakers you are driving and how many, room size, listening levels you want.
The speakers I am currently running are:

I live in an apartment and the room they are placed in is a living room, dining room, kitchen, and entryway combination with just a waist high bar/counter between the kitchen and the others. As for my listening levels they seem to be around 60 – 80 SPL, with 80 being rare and possibly and error/issue with the cheap radio shack meter I am using.

Might want to expand on this, lots of information out there that's meaningless when it comes to amps
I can't mention every article and video I have referenced regarding this, but some are AVS Forum, Sound & Vision, Secrets of Home Theater and High Fidelity, And of course Audioholics.

Now I will start out with wattage which I have heard two different things about what it determines in sound. The first being that increasing the output power of an amplifier will give you cleaner and clearer audio. The second being that increasing the output power of an amplifier will just increase the maximum SPL value that can be output by a speaker. Now these two are not mutually exclusive, but if the second is true how would the first be true as well? I have also heard that it is not just the output power of an amplifier, but how much of that power it can drive without going into high distortion. Bu what is considered high distortion? I have heard numbers from 10% all the way down to 1%.


Now another bit of information I have found that I find quite puzzling is that speakers will normally only output sound a 1 watt of power most of the time. If this is true then why would you need more than 1 watt of output? And why do people go for amplifiers that output say 500 watts of power?
 
slipperybidness

slipperybidness

Audioholic Warlord
The simple answer to this is no, not with my current listening environment and equipment. That said, I started looking at amplifiers because of my desire to upgrade to UHD, which would require me to upgrade my receiver. My exploration into upgrading my receiver has made me feel that separates are the better route, so that amplification and pre-amplification are separate purchases. Also so that each subsequent upgrade I am not repurchasing amplification, as I would with a receiver.




The speakers I am currently running are:

I live in an apartment and the room they are placed in is a living room, dining room, kitchen, and entryway combination with just a waist high bar/counter between the kitchen and the others. As for my listening levels they seem to be around 60 – 80 SPL, with 80 being rare and possibly and error/issue with the cheap radio shack meter I am using.



I can't mention every article and video I have referenced regarding this, but some are AVS Forum, Sound & Vision, Secrets of Home Theater and High Fidelity, And of course Audioholics.

Now I will start out with wattage which I have heard two different things about what it determines in sound. The first being that increasing the output power of an amplifier will give you cleaner and clearer audio. The second being that increasing the output power of an amplifier will just increase the maximum SPL value that can be output by a speaker. Now these two are not mutually exclusive, but if the second is true how would the first be true as well? I have also heard that it is not just the output power of an amplifier, but how much of that power it can drive without going into high distortion. Bu what is considered high distortion? I have heard numbers from 10% all the way down to 1%.


Now another bit of information I have found that I find quite puzzling is that speakers will normally only output sound a 1 watt of power most of the time. If this is true then why would you need more than 1 watt of output? And why do people go for amplifiers that output say 500 watts of power?
The GE T2 is a fairly easy speaker to drive to satisfying levels. And, you live in an apartment.

What AVR are you using now? I run my GE T2 off my Pio Elite VSX-82 it does an honest 140W per channel and that is more than enough power for the GE T2s.

Honestly, I suspect adding an amp is likely not worth the $ for your speakers and your living situation. If I were you I would be looking to spend that money on other areas--

*A better sub--but probably a moot point in an apartment.
*Add surrounds--but stick to 5.1 (7.1 is only useful for a very large seating area)
*Add it to the $ for the TV upgrade to afford a bigger TV!
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
O agree. Just upgrade to the avr with full HDR/UHD support and have pre-outs. Don't worry about adding amp now.

Sent from my VS986 using Tapatalk
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
You'd be able to get more than 80 dba out of 30wpc amplifier

Sent from my VS986 using Tapatalk
 
lovinthehd

lovinthehd

Audioholic Jedi
I can't mention every article and video I have referenced regarding this, but some are AVS Forum, Sound & Vision, Secrets of Home Theater and High Fidelity, And of course Audioholics.

Now I will start out with wattage which I have heard two different things about what it determines in sound. The first being that increasing the output power of an amplifier will give you cleaner and clearer audio. The second being that increasing the output power of an amplifier will just increase the maximum SPL value that can be output by a speaker. Now these two are not mutually exclusive, but if the second is true how would the first be true as well? I have also heard that it is not just the output power of an amplifier, but how much of that power it can drive without going into high distortion. Bu what is considered high distortion? I have heard numbers from 10% all the way down to 1%.


Now another bit of information I have found that I find quite puzzling is that speakers will normally only output sound a 1 watt of power most of the time. If this is true then why would you need more than 1 watt of output? And why do people go for amplifiers that output say 500 watts of power?
Increasing the output of an amp increases the spl delivered from the speakers; whether that will be cleanly delivered by your speakers depends on the capabilities of your speakers (your amp may well be more capable than your speakers, and the wattage rating of your speakers doesn't necessarily relate to that clean output level, it's more a melting point rating). Distortion figures from amps are largely an exercise in statistics rather than an audible level, your speakers will have much more distortion than your amp.

Just because an amp has a rating of say .1% distortion at a given wattage, doesn't mean it can't be driven to higher levels of both power and distortion, just look at various bench tests of amps as to where the relationship of power to distortion starts to rise (like this one from another avr from Pioneer similar to yours http://www.soundandvision.com/content/pioneer-elite-sc-89-av-receiver-review-test-bench#bfo2kj7L8eEoSieh.97)

Speakers don't output watts, but at one watt input many speakers can output a significant spl; sensitivity ratings are what a speaker outputs with one watt (2.83V at 8 ohm) input at 1 meter distance from the speaker, and it will take a doubling of power for each additional 3dB of output from the speaker. At often-used spls most speakers are only using a few watts power.
 
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ski2xblack

ski2xblack

Audioholic Samurai
Separates make sense from a system design standpoint, but once you start pricing it out it makes less economic sense. If you determine that you don't need huge wattage, then upgrading your receiver will likely be the cost effective solution.

I can't mention every article and video I have referenced regarding this, but some are AVS Forum, Sound & Vision, Secrets of Home Theater and High Fidelity, And of course Audioholics.

Now I will start out with wattage which I have heard two different things about what it determines in sound. The first being that increasing the output power of an amplifier will give you cleaner and clearer audio. The second being that increasing the output power of an amplifier will just increase the maximum SPL value that can be output by a speaker. Now these two are not mutually exclusive, but if the second is true how would the first be true as well? I have also heard that it is not just the output power of an amplifier, but how much of that power it can drive without going into high distortion. Bu what is considered high distortion? I have heard numbers from 10% all the way down to 1%.

Now another bit of information I have found that I find quite puzzling is that speakers will normally only output sound a 1 watt of power most of the time. If this is true then why would you need more than 1 watt of output? And why do people go for amplifiers that output say 500 watts of power?
This is a topic that has been discussed to death, but here is a hint: transient peaks require gobs of power to reproduce faithfully. If you're using an average of 1 watt, which given whatever speaker sensitivity and listening distance results in 65 db at your listening position, a 20 db peak would require 100 watts, for 85 db at the listening position. That's not unreasonably loud peak output, yet is beyond the capability of many entry level AVRs. An amp that can amplify such transient peaks faithfully will sound "cleaner and clearer" as you put it, even at normative levels. For most folks, and specifically you, with reasonably sensitive speakers in an apartment setting, that can most likely be accomplished with a decent AVR (one that has legit full bandwidth 4 ohm ratings at power levels slightly above what you'll reasonably need).
 
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M

mortizar

Audiophyte
So say I was to go against everyone’s wonderful advice and decided to purchase an amplifier. Then my though process on the amplifiers I have listed is as follows. The D-Sonic amplifiers do not list the impedance at which the power ratings are measured. Because of this I am hesitant buy them since it feels they are hiding something with their amps. The Wyred 4 Sound MMC amplifiers is out of stock and the MC amplifiers is really pushing, if not over, what I am willing to pay.


This would leave just the Emotiva XPA and the NAD Masters M27. So the NAD M27 states it can output 180 Watts at 8 ohms 20Hz – 20kHz, and 320 Watts at 8 ohms IHF Dynamic Power. The 180 Watts is straight forward, but I am unclear on the IHF Dynamic Power. Now the Emotiva XPA-7 is even more unclear to me, it lists 300 Watts 20Hz – 20kHz at 8 ohms per channel. However it also lists that the seven channel model as being 200 Watts at 8 ohms, but does not qualify at what frequency this rating is measured at. So which is it for the Emotiva XPA-7, anyone have an idea?


Now given all of that and considering the need to double the wattage to gain 3 Db of SPL, both the NAD M27 and Emotiva XPA-7 fail to obtain the 256 Watts level. What I mean is with the previous doubling having happened at 128 Watts neither can reach the next jump of 3 Db at 256 Watts. So seems like my best choice with these would be to go with the Emotiva XPA-7 and use difference between it and the M27 to purchase the surround portion of my system. Any agree, disagree, or “I stupid” comments?


Going along with this train of thought, I have some questions on speaker layout of my surrounds. I have them because my room is kind of an odd layout; a diagram of it is listed below.



So the blue boxes are the speakers I have at the moment, with the red boxes being where I propose I put the surround speakers. Originally I thought to start out with moving to a 5.1 system, but the guy at the audio store said I would need the sides to be more behind the listing position and not slightly forward of it. Now this is really not possible because of that L-shaped part of the room on the right. So my solution was think of going straight to a 7.1 system, would this work? Or is the fact that my sides are slightly forward a big no no?


Now I feel I should mention the rear surrounds distance from the listing position. The right rear surround would be at about 6’ from the sofa and the left rear surround would be about 9’ from the sofa. Is there any reason why this would not work? What I mean is do the two rear surrounds need to be the same distance from the listing position?
 
lovinthehd

lovinthehd

Audioholic Jedi
Not sure where the 128 watts thing is based on, but does illustrate just how much power it takes to gain a few dB. Here's what I see for the XPA-7 ratings in the manual:
200 watts RMS per channel @ < 0.02% THD; all channels driven; into 8 Ohms.
520 watts RMS per channel @ < 0.1% THD; two channels driven; into 8 Ohms.
315 watts RMS per channel @ < 0.2% THD; all channels driven; into 4 Ohms

D-Sonic specs here http://www.d-sonic.net/products/ which do leave some questions but does appear to be a more powerful amp than the XPA-7 or M27.

You might also consider the ATI built Monoprice Monolith 7 amp, or amps from ATI themselves.
 
S

shadyJ

Speaker of the House
Staff member
One argument for separate amplifiers is that they remove a lot of heat from the pre-amp stage, and this should greatly extend its life. Heat is the enemy of electronics, and the more there is, the shorter the life of that component. I doubt that you will be able to tell any audible difference between your AVR amp and a beefy separate, and I really doubt you will be taking advantage of the extra headroom that it will provide. You would be surprised how loud a few watts is with most speakers. But the improvement comes with reliability, not audibility. If you have a high-end AVR or something with a very nice pre-amp section, then there may be an argument for it. The best time to go the separate amp route is if you are shopping for the pre-amp at the same time, so you don't buy a redundant amplifier in an AVR or something like that.
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
You had mentioned that math may not be your strong point, but I hope this site will help to get you better understanding.
http://myhometheater.homestead.com/splcalculator.html
If you plug in numbers as below:
Speaker Sensitivity: Measured by audiophool magazine to be 91 db SPL 1W/1M
Amp power: I started with 100W, but you could play with it. Every 6db volume level is perceived by humans to be twice as loud.
Distance (from speakers to your ears): I guessed 8 ft
Number of speaker: 3
Placement: In corner or near it (upto 2 feet)

Result is 114 dB SPL at listening position. What is 114db? This graph might help:
It's somewhere between Jackhammer/Chainsaw and a Rock concert.





but I know, that you're going to ignore all that, so take at least this for my advice - buy highly reputable and extremely high quality ATI or Parasound Amp
 
M

mortizar

Audiophyte
Not sure where the 128 watts thing is based on
The 128 number I pulled from this article. In particular this part of it where they calculate each increase in loudness, the 3 Db increase, and at which wattage values it occurs at, starting at 1 watt.

Now, you’ve got two speakers, so there’s some addition to the 86 SPL figure because of that. You are also about 8-10 feet away from the two speakers (and somewhat off axis, to boot), so there’s some reduction because of that (the inverse square law, which says that SPL reduces by -6 dB as the distance doubles). Throw in your room’s absorptive characteristics, any open walls that lead to the next room, etc, and what you’re left with is that the raw sensitivity figure for one speaker is a pretty decent number to work with as to how loud two speakers will sound from your listening position with a 2.83V (1 watt into 8 ohms, 2 watts into 4 ohms) input. There are a LOT of variables, obviously, but 86dB for 1 watt per speaker for a pair of speakers from your listening chair is not a bad estimate.

Editorial Note about Inverse Square Law & Real Rooms

We’ve all heard the -6dB inverse square law of SPL reduction for every doubling of distance but in reality that pertains to free space, or an anechoic chamber – which is a room without echoes. Real world listening rooms will see more along the lines of 3-4dB of loss for every doubling of distance. But for arguments sake, we stick to the common -6dB figure for all of our calculations in this article. Just recognize the real world losses should be much less, unless of course you live in an anechoic chamber or are listening to your speakers outdoor in free space.

Every doubling of power is another +3dB of loudness. So:

2 w = 89 dB

4 w = 92 dB

8 w = 95 dB

16 w = 98 dB

32 w = 101 dB

64 w = 104 dB

128 w = 107 dB

256 w = 110 dB
So my train of logic is based on the "each perceivable increase in loudness requires a doubling of power". Now the way this can be used is one of two ways. The first being that is in saying “my amplifier/receiver can power all my channels at X wattage”, which would mean when upgrading my amplifier in order to get one level of perceivable loudness increase the new amplifier must be able to drive all my channels at twice that amount, or 2X.


The second way of is to consider your amplifier to start powering your speakers at 1 watt of power. You would then go about raising the volume with each doubling of power giving you a perceivable increase in loudness. The NAD M27 has a continuous power rating of 180 watts at 8 ohms and the Emotiva XPA-7 has a continuous power rating of 200 watts at 8 ohms, at least according to the spec sheets. This means starting at a power output of 1 watt and cranking it up the maximum perceivable loudness level they both can achieve, at the continuous power rating, is 128 watts. To increase the perceivable loudness again they would have to move up to 256 watts of output, which neither of them can do with their continuous power rating. Now both list a dynamic power rating higher than 256 watts. The Emotiva implies it when it says:


ALL MODELS: Power Output Per Channel

300 watts RMS per channel; 20 Hz - 20 kHz; THD < 0.1%; into 8 Ohms
And NAD M27 says it with its IHF Dynamic Power Rating of 275 watts.


This is my understanding of it, which could be wrong. My thought process on it could also be wrong. But assuming that it is correct, then that would mean that both amplifiers are capable of powering my speakers at the same level. Thus it would make no sense for me to spend an extra $2k for the NAD M27.
 
M

mortizar

Audiophyte
Amp power: I started with 100W, but you could play with it. Every 6db volume level is perceived by humans to be twice as loud.
Swear I had heard that the doubling the loudness was 3 Db, but that article I linked does specifiy 6 Db further down so guess I was wrong on that. Feel that most of my logic is still correct though.

buy highly reputable and extremely high quality ATI or Parasound Amp
I had checked them out but don't think really like there weight specs, 70 - 90 lbs does seems to much for my AV rack and nor do I like the idea of carrying them up to my third floor apartment.
 
lovinthehd

lovinthehd

Audioholic Jedi
The 128 number I pulled from this article. In particular this part of it where they calculate each increase in loudness, the 3 Db increase, and at which wattage values it occurs at, starting at 1 watt.



.
That article was assuming a speaker with 86dB sensitivity as an example (or a reading at a measured position of 86dB with 1 watt power). Your speakers are 91 dB sensitive so your amp power goes further with your speakers. You should play with that spl calculator some....
 
lovinthehd

lovinthehd

Audioholic Jedi
Swear I had heard that the doubling the loudness was 3 Db, but that article I linked does specifiy 6 Db further down so guess I was wrong on that. Feel that most of my logic is still correct though.



I had checked them out but don't think really like there weight specs, 70 - 90 lbs does seems to much for my AV rack and nor do I like the idea of carrying them up to my third floor apartment.
A doubling of amp power gets you 3dB more spl. 6-10dB is the range where people say the apparent loudness has doubled.
 
S

shadyJ

Speaker of the House
Staff member
You will never use 100 watts continuously, trust me. And, per a comment you made earlier, you are certainly listening at levels above 80 dB. You aren't reading your RS SPL meter correctly. If you try pumping 100 watts into your speakers for more than a fleeting moment, you will be evicted from your apartment. The NAD won't provide any sonic benefits over the Emotiva amp in your situation. I run sensitivity tests on speakers by playing tones at certain frequencies and measuring the output of the speaker at 1 meter for 2.83v, which at 8 ohms is 1 watt and at 4 ohms is 2 watts, and it is usually quite loud, we are talking 85 to 90 dB. And that is at an outdoor location without the boundary reinforcement of in-room conditions. Buying an expensive amp is just a waste of money.
 
ski2xblack

ski2xblack

Audioholic Samurai
Mortizar, to clarify those IHF method dynamic power ratings that NAD has always used over the years, they use those to provide what they consider a better idea of "music power", as opposed to continuous or RMS power. Test tones have a low crest factor (the difference between the average level and peak level), where music generally has a much, much higher crest factor. The IHF method involves short term bursts of power followed by silence, and tends to produce inflated numbers, but there is some sense to it since we listen to music and not test tones.

That being said, the NAD is the worst value proposition on your list IMO. The Emo is probably the best value proposition. And, as I and the others have said, external amplification in your situation would effectively be mis-allocated dollars for power that you in all likelihood would never actually use. That's the rub with power amps. Too much is just enough, because you don't want clipping, ever, but unused power simply goes unused. It's up to you to determine if you really need the amps, or if you can get by with an AVR rated for 125 w or so. (In one rig I use a Marantz SR6007, not a powerhouse but not a slouch either, in a larger room than yours, with less sensitive speakers than yours-although dual subs really help out, and have no lack of power for any volume I care to listen at.)
 
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