Is buying a separate amp worth the money?

[orion8301]

Is buying a separate Amp worth the money for my setup?

My wife and I are thinking of buying an Outlaw Audio 5000 to power FL/FR/C/BL/BR and letting the receiver power the Surrounds.

Our current setup is an Aperion Intimus 7.2 system. We split usage 50/50 for Movies/Music. Like many, we do not have a dedicated theater room. Just a very accommodating wife that lets me do as I like in the Living room. For Christmas we purchased the Yamaha RX-V 779 to power our current Aperion Intimus 7 channel set, we bought together 8+ years ago.

The Living room is 13' X 18' X 20' = 4,680 cuft

The Yamaha RX-V 779 is rated to 95 W/ch @ 2ch driven.
Pushing a 7 channel system will pull on this Yamaha RX-V 779 a bit more, but the confusion sets in when you try to factor in dual 12" dedicated subs handling the lows, all speakers are small crossed over at 80Hz. By offloading the bass frequencies below 80Hz, further reducing the integrated Amps draw for the speakers, does that alleviate the need to buy a separate amp? Would adding the separate amp make our setup sound that much better, providing higher, cleaner power the integrated amp simply can't produce?

Sound and Vision published a nice page on the Yamaha RX-V 775 that details the drop off of the integrated amplifiers power per channel that has started this entire line of questioning.

0.1% THD 1.0% THD
2 Channels Continuously Driven, 8 ohm loads 122.8 watts 147.5 watts
2 Channels Continuously Driven, 4 ohm loads 149.7 watts 181.9 watts
5 Channels Continuously Driven, 8 ohm loads 38.2 watts 55.2 watts
7 Channels Continuously Driven, 8 ohm loads 32.2 watts 41.3 watts <=== This is my world


Attached is a JPEG of the room, distances to the speakers and the speaker sensitivity ratings + Nominal Ohm rating.

Aperion Audio Intimus 533-VAC <---- Center
Frequency response: 80hz to 20Khz
Nominal speaker impedance: 8 ohms & 87dB/W/m
Recommended power: 50-150 watts
Speaker enclosure type: 3-Way Sealed, Video Shielded
Tweeter (diameter): 1"
Midrange (diameter): 4"
Woofer (diameter): 5.25"

Aperion Audio Intimus 533-T <---- Front L/R
Frequency response: 65Hz to 20KHz
Nominal speaker impedance: 8 ohms & 89dB/W/m
Recommended power: 50-200 watts
Speaker enclosure type: 2-1/2 Way Vented, Video Shielded
Tweeter (diameter): 1"
Woofer (diameter): Dual 5.25"
Dimensions (HxWxD): 38.5" X 9.25" X 10.75"
Weight: 38 pounds each

Aperion Audio Intimus 534-SS <---- Surround
Frequency response: 90hz to 8Khz (Bipole) <===
Frequency response: 60hz to 14Khz (Dipole)
Nominal speaker impedance: 12 ohms & 88 dB/W/m
Recommended power: 50-300 watts
Speaker enclosure type: Sealed
Tweeter (diameter): 1"
Woofer (diameter): 5.25"

Aperion Audio Intimus 5B <---- Rear
Frequency response: 75hz to 20Khz
Nominal speaker impedance: 6 ohms & 84dB/W/m
Recommended power: 50-150 watts
Speaker enclosure type: 3-Way Sealed, Video Shielded
Tweeter (diameter): 1"
Midrange (diameter): 4"
Woofer (diameter): 5.25"

 

[PENG]

With this kind of details, you are going to get some good suggestions as soon as people have time to digest and do their calculations.

 

[fmw]

Maybe but probably not. The missing element is the volume level you plan to employ. If you listen at 15 db under like I do, then the amp won't change anything. If you listen at reference then it might matter. Reference would have me reaching for ear plugs but some people do listen at that level.

In my view the vast, vast majority of accessory amplifiers are purchased because they are wanted, not because they are needed.

 

[Swerd]

First of all, welcome to Audioholics! Thanks for providing all those details about your system. It helps to answer your question.

Is buying a separate Amp worth the money for my setup?

My short answer would be maybe. However the benefit you may hear will probably be subtle at best. It also depends on the price you pay for a separate amp.

It pays to remember that power is an estimate, not a direct measurement. It's calculated based on direct measurements of voltage and current. Current varies with the impedance, and in speakers, impedance varies with the frequency of the audio signal. It isn't constant. Power also varies significantly with time. Some sounds, which demand high power, are very short, while others last longer.

Your AVR uses one large power supply transformer to deliver power to as many a 7 channels. You seem to be familiar with how that affects the amount of power available per channel. It's important to remember that most of the power in a movie goes to the front 3 speakers. The various surround channels draw much less power.

To answer your question about subwoofers: Yes, using dedicated subwoofers to handle lower frequencies will relieve your AVR of the burden of driving the main speakers at those frequencies. That can make a significant difference.

Would adding the separate amp make our setup sound that much better, providing higher, cleaner power the integrated amp simply can't produce?

Now for the hand waving . Your question can be difficult to answer clearly because the differences from more amplifier power can be subtle and hard to easily describe in words. A number of years ago I added an external 200 wpc 2 channel amp to my existing AVR so it drove my front L and R speakers. The AVR was a modest Denon rated at 70 wpc. So the power increase for the two main speakers was about triple.

At first I couldn't say I noticed anything had changed. But soon I noticed that the speaker's bass (without a sub woofer) seemed a little more crisp and firm (less bloated?) on certain musical selections. It was subtle, and depended on the music, so it wasn't always noticeable. Within a few weeks I started noticing that I was listening at louder levels without noticing that it was uncomfortably loud. So I started turning it down. My cues for what was uncomfortably loud sound had changed while I hadn't noticed it.

Apparently, with the AVR I had judged when to turn down the volume by the amount of noise or distortion I was hearing. When I started using the bigger amp, those noise cues were less noticeable. It's not unlike driving a car, where I could estimate my speed by listening to road noise. If I got new tires, or drove on smoother pavement, those cues changed and my sense of speed was wrong. The more powerful amp was apparently quieter, as in less noisy than the smaller amp, while driving the speakers louder.

I bought that 2 channel 200 wpc amp used in 2009; it cost me $400, or $1 per watt. I use it to drive my two main speakers, and the AVR drives the center and two rear channel speakers.

I hope you can use all this info and hand waving to decide whether you would benefit from adding an Outlaw Audio 5000 amp to power 5 speakers while letting your fairly potent Yamaha AVR power only the surrounds. You might do well without any external amp (as fmw suggested above), and you might do well with adding a 2-channel amp as I did. There is a good market in used amps.

I hope this makes sense .

 

[TLS Guy]

I think it all depends on your listening choices and your volume level.

For rock music the average level is high. For classical music the average level is low, but the peak level high and they can be sustained long enough to run amps out of gas. I would say classical music has the highest power demands for realistic reproduction, with movies being a second and compressed rock music last unless you always play at ear damaging levels.

The other issue is that your speakers are very much middle of the range. At that price point I would expect significant thermal compression at power. This latter issue could very well limit your benefit from increased power.

From my perspective, and given some of the program I listen to, high power has been vital for effortless reproduction, and I have lots of it.

 

[Swerd]

The consensus answer seems to be a definite maybe (with some reservations). If so, why did I ever spend any money on an additional external amplifier?

I used to regularly attend a yearly get together of DIY speaker builders in my local area. At one of those meetings, a guy named Bob Cordell did a demo about amplifier power and clipping. The take home lesson for me was: 1) amplifier clipping happens at low levels (10% or less) without being audible, and 2) if you're interested in good sound, your amp should never ever clip.

Cordell went on to repeat & refine his demo, described here:
https://web.archive.org/web/20090107021358/http://www.cordellaudio.com/rmaf/workshop5.shtml

 

[highfigh]

Is buying a separate Amp worth the money for my setup?

My wife and I are thinking of buying an Outlaw Audio 5000 to power FL/FR/C/BL/BR and letting the receiver power the Surrounds.

Our current setup is an Aperion Intimus 7.2 system. We split usage 50/50 for Movies/Music. Like many, we do not have a dedicated theater room. Just a very accommodating wife that lets me do as I like in the Living room. For Christmas we purchased the Yamaha RX-V 779 to power our current Aperion Intimus 7 channel set, we bought together 8+ years ago.

The Living room is 13' X 18' X 20' = 4,680 cuft

The Yamaha RX-V 779 is rated to 95 W/ch @ 2ch driven.
Pushing a 7 channel system will pull on this Yamaha RX-V 779 a bit more, but the confusion sets in when you try to factor in dual 12" dedicated subs handling the lows, all speakers are small crossed over at 80Hz. By offloading the bass frequencies below 80Hz, further reducing the integrated Amps draw for the speakers, does that alleviate the need to buy a separate amp? Would adding the separate amp make our setup sound that much better, providing higher, cleaner power the integrated amp simply can't produce?

Sound and Vision published a nice page on the Yamaha RX-V 775 that details the drop off of the integrated amplifiers power per channel that has started this entire line of questioning.

0.1% THD 1.0% THD
2 Channels Continuously Driven, 8 ohm loads 122.8 watts 147.5 watts
2 Channels Continuously Driven, 4 ohm loads 149.7 watts 181.9 watts
5 Channels Continuously Driven, 8 ohm loads 38.2 watts 55.2 watts
7 Channels Continuously Driven, 8 ohm loads 32.2 watts 41.3 watts <=== This is my world


Attached is a JPEG of the room, distances to the speakers and the speaker sensitivity ratings + Nominal Ohm rating.View attachment 17151




Aperion Audio Intimus 533-VAC <---- Center
Frequency response: 80hz to 20Khz
Nominal speaker impedance: 8 ohms & 87dB/W/m
Recommended power: 50-150 watts
Speaker enclosure type: 3-Way Sealed, Video Shielded
Tweeter (diameter): 1"
Midrange (diameter): 4"
Woofer (diameter): 5.25"

Aperion Audio Intimus 533-T <---- Front L/R
Frequency response: 65Hz to 20KHz
Nominal speaker impedance: 8 ohms & 89dB/W/m
Recommended power: 50-200 watts
Speaker enclosure type: 2-1/2 Way Vented, Video Shielded
Tweeter (diameter): 1"
Woofer (diameter): Dual 5.25"
Dimensions (HxWxD): 38.5" X 9.25" X 10.75"
Weight: 38 pounds each

Aperion Audio Intimus 534-SS <---- Surround
Frequency response: 90hz to 8Khz (Bipole) <===
Frequency response: 60hz to 14Khz (Dipole)
Nominal speaker impedance: 12 ohms & 88 dB/W/m
Recommended power: 50-300 watts
Speaker enclosure type: Sealed
Tweeter (diameter): 1"
Woofer (diameter): 5.25"

Aperion Audio Intimus 5B <---- Rear
Frequency response: 75hz to 20Khz
Nominal speaker impedance: 6 ohms & 84dB/W/m
Recommended power: 50-150 watts
Speaker enclosure type: 3-Way Sealed, Video Shielded
Tweeter (diameter): 1"
Midrange (diameter): 4"
Woofer (diameter): 5.25"

I think two of the most important details have been left out- the room's characteristics (shape, furnishings and anything that could affect the acoustics) and your program material. As TLS posted, rock can be loud, but one of the main things about Rock is that the dynamic range is usually lower than Jazz, Classical and some other types, which can be a big problem for a multi-channel AVR because it's designed to play at a moderate level, not deliver on demand, at its upper limit. A separate power amp should be able to provide output that is less compressed, distorted and a strain for the power supply, but at some point, the SPL may be high enough that any measure of quality for the sound is gone- it's just loud.

That said, the distance from you to the speakers should mean that SPL isn't a problem- if the Width is measured as you show the speaker positions, you have four speakers very close to you, you're close to the back yard and there's not much space behind the speakers. This means you'll perceive higher loudness than if you were farther from the wall but it can also mean that you're sitting in a place where the room's acoustical modes may be working against you. If you move your hear while you sit, do you hear a change in the low frequency response? I would address that before anything else. Adding power to a system that may be limited by the room is an uphill climb.

I think I would listen to the system without the sub turned on- if you can achieve the SPL you need for all sources and material without setting the volume control near the maximum, some questions need to be answered:

Will the sub be able to keep up with higher power going to the main speakers?
Do you actually need higher SPL, or do you want more power for better dynamics?

 

[fmw]

2) if you're interested in good sound, your amp should never ever clip.

Of course but few people understand clipping and don't have a way to measure it. That results in people buying amplifiers "just in case." There should be a better way. I know that my amps never clip because I have measured them. Not many people know how to do that. Perhaps the industry needs to develop a "clipping parameter" specification of some sort. Truthfully, clipping is pretty rare in home audio systems. Mostly you will find it at parties with "rock concert" SPL's. People who do that need to worry about amplifier power. The rest of us really shouldn't worry about it.

In my exercise room I have a cheap 40 watt per channel integrated amp. It produces clean sound well beyond my willingness to advance the volume control.

 

[Swerd]

Of course but few people understand clipping and don't have a way to measure it. That results in people buying amplifiers "just in case." There should be a better way. I know that my amps never clip because I have measured them. Not many people know how to do that. Perhaps the industry needs to develop a "clipping parameter" specification of some sort.

It would be nice if all amplifiers and receivers had accurate and fast clipping indicators.

Truthfully, clipping is pretty rare in home audio systems. Mostly you will find it at parties with "rock concert" SPL's. People who do that need to worry about amplifier power. The rest of us really shouldn't worry about it.

I certainly cannot argue with that. At the same time, that demo I spoke of persuaded me to at least consider getting a bigger amp. A Rickie Lee Jones cut was played at realistic, but certainly not unpleasantly loud levels in a normal sized room, on speakers with an estimated sensitivity of about 89 dB. I remember the volume level allowed me to talk to the person next to me without raising my voice to be heard.

Two meters were used. One read average "continuous" power (over the last 15 seconds), and the other showed "instantaneous" peak power (as short as ~20 microseconds). The average power meter typically read no more than 1-2 Watts, while the power on peak meter occasionally topped 250 Watts. On this cut, those dynamic peaks occurred with a single thwack to a snare drum. In the demo, two different amps were tested. One was 100 wpc and the other 250 wpc. The 100 wpc amp clipped, only during the short time of the drum thwack. No one in the room could hear a difference between the two amps.

Those were the facts that I remember. It comes down to which philosophy works for you. Get enough power for most any "instantaneous" peak demand (aka "just in case"), or get sufficient power for the "continuous" average demands. I don't think there is a strong case for one over the other.

 

[Seth=L]

I'll briefly answer the question twice.

Answer # 1

There is a misnomer that benchtests represent real world use. Chances are the only reason the Yamaha presents such low output in 5 and 7 channel tests is because of a logical current limit imposed by the receiver reacting to a constant load. Real world scenarios won't present this kind of load. All channels driven figures aren't an end all be all. Again, in real world scenarios the likelihood of needing 95 watts for all channels at the same time is pretty much never.

Answer # 2

Adding an external amplifier could and likely will improve your dynamic headroom, especially at reference levels of output. Let's assume you're listening to music at 10 watts average, if your program has 12dB of headroom that would require 160 watts to achieve that peak. If you're listening to program at 20 watts average and 12dB headroom would need 320 watts to achieve that peak.

 

[fmw]

Adding an external amplifier could and likely will improve your dynamic headroom, especially at reference levels of output. Let's assume you're listening to music at 10 watts average, if your program has 12dB of headroom that would require 160 watts to achieve that peak. If you're listening to program at 20 watts average and 12dB headroom would need 320 watts to achieve that peak.

10 watts average would be those "rock concert levels" to which I referred above. That's huge. Most of us don't see that except on peaks.

 

[Seth=L]

10 watts average would be those "rock concert levels" to which I referred above. That's huge. Most of us don't see that except on peaks.

I've often theorized that the biggest peaks are the ones that equipment may not be able to register for a lack of speed. I could be way off base there. I can definitely say without any reservation that the little 25 watt per channel Teac CR-H220 I had cannot reach reference levels at all, and some of the 50 watt amplifiers I have had don't do so without significant audible stress.

 

[fmw]

I've often theorized that the biggest peaks are the ones that equipment may not be able to register for a lack of speed. I could be way off base there. I can definitely say without any reservation that the little 25 watt per channel Teac CR-H220 I had cannot reach reference levels at all, and some of the 50 watt amplifiers I have had don't do so without significant audible stress.

I don't doubt that but most people consider reference levels to be uncomfortably loud so most of us don't encounter the problem.

 

[Seth=L]

I don't doubt that but most people consider reference levels to be uncomfortably loud so most of us don't encounter the problem.

How am I ever going to be right if you keep correcting me?

 

[fmw]

I'm just trying to add to the general knowledge. If you have a calibrated AV receiver you can watch a movie at the 0 db setting and decide for yourself if that is a good listening level for you. If it is, then my comments don't matter. I don't think you said anything wrong. I'm just adding some context.

 

[orion8301]

Time to provide feed back. Consensus so far is, don't waste my money, put it towards the retirement fund.

As I've aged from my early twenties into now near 40, my listening tastes have changes from hard rock to more blues and folk.

In my twenties, it was Tool, Metallica, Guns and Roses, Stone Temple Pilots, Nirvana, Nine Inch Nails
In my late thirties now, it is Ray LaMontaigne, Damien Rice, Sia, ZZWard, The Black Keys. Something with soul that makes you appreciate the system you invested in.
(Every now and then we throw something heavy on to get the excitement level up)

As for movies, Sci-Fi and Animation rules the roost: Guardians of the Galaxy, Star Wars, Star Trek, Avengers, Batman Begins, Iron Man, Avatar, Inception, Jurassic World, Interstellar, 9, Godzilla, Pacific Rim, Kung Fu Panda, Any Pixar or Dreamworks production. Having a young kid dictates some of the selection too.

The best reason for this post is "some" content sounds thin or hollow like there is something missing. This could all be based on the source, because "Master and Commander" at 9 minutes into the film is insane. Cannon fire, wood splintering, the ship hull creaking. The other side of that coin is Star Wars III "Revenge of the Sith" last night seemed to have bass and highs, but was missing the jaw dropping sound that Master and Commander provided.

As for Music Ray LaMontaigne, Sia, Damien Rice are amazing, we generally run 7ch stereo for Music. We never run in 2ch, enveloping, immersive sound is what we love. having the side and rear channels so close actually adds to the feel. Also there is no other place to locate the rear and surround speakers in the living room.

Movies have been the only audible gap in the setup, music has been fantastic. Again it is not all movies (BlueRay and DVD), but it is quite a few that seem lack luster. Bass is not an issue, Highs are not an issue, but this mid-range thin, hollow gap is my issue.

It makes me question power, placement, speakers being used.
Front towers are towed in 15 degrees
Subs are corner loaded
Center is ear level (Match height of the FR/FL tower tweeter)
The YPAO has been ran
The Parametric EQ is at Natural

As for the room, this is a living room with couches, book shelves, paintings, windows. (Walk in your living room and mine is probably not much different)

The key thing in this room is;
It is 13 feet from back of the room to the TV
It is 18 feet wide looking at the TV panning left to right
The ceiling is 20 feet up, (Changing a light bulb will make you pucker up)

 

[PENG]

I've often theorized that the biggest peaks are the ones that equipment may not be able to register for a lack of speed. I could be way off base there. I can definitely say without any reservation that the little 25 watt per channel Teac CR-H220 I had cannot reach reference levels at all, and some of the 50 watt amplifiers I have had don't do so without significant audible stress.

Seth, if it was that quick, then you really wouldn't be able to hear the effects of such "quick"= super short peaks that didn't even get registered (according to you) in the first place. Or may be I misunderstood your point.

 

[fmw]

The best reason for this post is "some" content sounds thin or hollow like there is something missing. This could all be based on the source,

I would agree that it is probably the source. The equipment can only reproduce what was there in the first place. It can't fill out "thin" spots.

 

[herbu]

Orion,
So much good information here. In my mind, this is what it all means...

> If you have the money for an amp, without affecting any other aspect of your life, get it.
If you have to sacrifice anything to get the amp, wait.

You may or may not hear a difference. But I can tell you most of us have one. And whether we think we can hear a difference or not, we keep it and use it.

 

[Steve81]

I'm just trying to add to the general knowledge. If you have a calibrated AV receiver you can watch a movie at the 0 db setting and decide for yourself if that is a good listening level for you. If it is, then my comments don't matter. I don't think you said anything wrong. I'm just adding some context.

One important point to consider: to perform this experiment properly, the system needs to be capable of competently reproducing reference levels in the first place. If you bump up the volume up to reference level with speakers that aren't up to the task, backed by an amp that's driven into clipping, most would be inclined to turn it down simply because it sounds horrible.

One might also consider that we essentially live life at "reference level". Mow the lawn? That's 85-95dB continuous. Go to a restaurant or bar? The levels can top 90dB there as well (or even 100dB for the noisier venues). Ever been to an airport? A commercial jet 1 mile away coming in for landing can push levels in excess of 100dB. Visit a park like Gravelly Point (situated less than 1000 feet from a runway at Reagan National Airport), and one can imagine how much that goes up. Funny thing though, in spite of the regular air traffic, it's a popular spot for joggers and bikers.