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How to adapt a Live PA, Behringer iNUKE NU1000 for HT Front L/R

post #1 of 30
Thread Starter 
My AVR is Yamaha RX-V773WA and front L/R are CSW Henry Kloss Tower-1 (rated at 250W RMS and 6ohms). I had been thinking about getting an Emotiva UPA-200 but then saw a sale at Musiciansfriend and after some quick research, bought a Behringer iNUKE NU1000 for $199 + tax.

The brief research I did, told me people do use Live power amps for HT but they need to be adapted a bit. The mods, as I understood are:
- Replace the stock fans with less noisy ones (a popular choice seems to be the NF-R8 80mm)
- Use the AVR's 12v trigger to switch the PA on/off
- Terminate the front L/R speaker cables into speakon plug.

What else? Does this seem like a reasonable choice given my L/R specs? The room's 25' x 12' x 9' (H).

Thanks
post #2 of 30
Personally, I would use the receiver to power the speakers.
post #3 of 30
While I doubt you'll see much advantage to the perhaps extra 50-60 w/ch (that's about 1-2 dB in terms of additional output), you might try running the amp and see if the fan is noticeable before modding (but believe I've seen that they're on the noisy side). I didn't think pro amps were generally set up for 12v triggers (I have Crowns that aren't at least) and since you don't have much other option to connect your speakers....
post #4 of 30
Thread Starter 
Quote:
Originally Posted by FMW View Post

Personally, I would use the receiver to power the speakers.

Quote:
Originally Posted by lovinthehd View Post

While I doubt you'll see much advantage to the perhaps extra 50-60 w/ch (that's about 1-2 dB in terms of additional output), you might try running the amp and see if the fan is noticeable before modding (but believe I've seen that they're on the noisy side). I didn't think pro amps were generally set up for 12v triggers (I have Crowns that aren't at least) and since you don't have much other option to connect your speakers....

How so? The Yamaha is going to drive the surrounds + Sr.Backs. If I drive the front L/R too with it, how much is it going to realistically be dedicate to the fronts? With a ~500W PS, I'd say as an AB class amp, 300W RMS distributed to 6 channels, as needed but that's with peek distortion. It is rated at 90W+90W at 0.09% THD so I would think 180 into 6 channels before more distortion comes in. I ran some rough tests between stereo mode and then adding two surround speakers to the AVR. Adding surrounds eats up roughly 20% more power at depending on the audio playing. So add Surr.Backs and another 20%. 180W - 40% leaves ~110W for the front L/R.

And that's not even taking into account all the dynamic range handling that gets off-loaded to the external amp. Right?

Sorry, I am not trying to assert my thoughts here. Just wondering aloud. I have no experience running an external amp but mostly reading and doing some testing on my current setup.

As always, please correct me if I am wrong smile.gif And, thanks.
post #5 of 30
I think you are wrong. Most people, including me don't use more than about 10 watts per channel (that includes peaks). My own average power dissipation is less than one watt per channel. 55 watts per channel is overkill for most home listening environments. I would use the receiver. It will do just fine.
post #6 of 30
Quote:
Originally Posted by sjavs View Post

How so? The Yamaha is going to drive the surrounds + Sr.Backs. If I drive the front L/R too with it, how much is it going to realistically be dedicate to the fronts? With a ~500W PS, I'd say as an AB class amp, 300W RMS distributed to 6 channels, as needed but that's with peek distortion. It is rated at 90W+90W at 0.09% THD so I would think 180 into 6 channels before more distortion comes in. I ran some rough tests between stereo mode and then adding two surround speakers to the AVR. Adding surrounds eats up roughly 20% more power at depending on the audio playing. So add Surr.Backs and another 20%. 180W - 40% leaves ~110W for the front L/R.

And that's not even taking into account all the dynamic range handling that gets off-loaded to the external amp. Right?

Sorry, I am not trying to assert my thoughts here. Just wondering aloud. I have no experience running an external amp but mostly reading and doing some testing on my current setup.

As always, please correct me if I am wrong smile.gif And, thanks.

Watts aren't chopped up the way you think with simple percentages as the dB scale is logarithmic, plus no idea how you did your measuring. Takes twice as much power (watts) to raise the spl by 3dB, so if you have 100w/ch to gain 3dB you need 200w/ch, to gain another 3dB 400w/ch. Then there's that multi-ch movie sound won't need much from the surrounds, and maybe somewhat more important if you've got multi-ch music recordings. Thinking of what needs to be amplified isn't sine waves used for testing, but rather music and soundtracks, the power demands aren't likely as high as you think. On the other hand, you could literally blow your speakers with too much power, too smile.gif

Are you using a sub? That also helps the avr. I'm just pointing out that amp gives you just a little more advantage in two channels...and if you added a center (as in your other post) then maybe even a 3 ch amp or two pro 2 ch amps (like I am using at the moment, Crown XLS1500s) (didn't finish, so p.s. here....if you need an outboard amp at all.

What is the sensitivity rating of your speakers? Usually you'll get more bang for your buck with more sensitive and more dynamic speakers than start up an amp collection.
Edited by lovinthehd - 1/12/14 at 7:16pm
post #7 of 30
Quote:
Originally Posted by FMW View Post

Personally, I would use the receiver to power the speakers.

+1.

The NU1000 is only rated at 160 wpc / 8 ohms.

The Yamaha RX-V773WA is rated at 95 wpc./ 8 ohms

Apparently the OP is unaware that these amps are less than 3 dB apart in terms of output power, which is like 6 clicks on his remote control's volume buttons. In short, not that much. He'd need 950 WPC to get the perceptions of "twice as loud" if his speakers would take that much power without dying on the spot.

Furthermore, I don't think the OP knows how much power he is currently using.

He could measure peak SPL and plug it into a peak power calculator like the one here:

http://myhometheater.homestead.com/splcalculator.html

This SPL meter would provide the necessary acoustic measurements:

http://www.ebay.com/itm/271167212819?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
post #8 of 30
Thread Starter 
Quote:
Originally Posted by arnyk View Post

+1.

The NU1000 is only rated at 160 wpc / 8 ohms.

The Yamaha RX-V773WA is rated at 95 wpc./ 8 ohms

The RX-V773WA 95 wpc/8ohm is when only two channels are driven. What happens when you drive 6-channels with it? Consider this bigger brother of the RX-V773WA, the RX-A1020 that is rated at 110 wpc/8ohm with 2-ch driven. It falls to ~63 wpc with 5 channels driven. With 7 channels driven, it goes down to 57 wpc @ 8ohms.
http://www.soundandvision.com/content/yamaha-rx-a1020-av-receiver-ht-labs-measures
Quote:
Originally Posted by FMW View Post

I think you are wrong. Most people, including me don't use more than about 10 watts per channel (that includes peaks). My own average power dissipation is less than one watt per channel. 55 watts per channel is overkill for most home listening environments. I would use the receiver. It will do just fine.

Less than 1watt per channel? You are kidding, right?

So there are multiple ways you can measure how much power is going to your speakers. What I did was plugged my previous AVR, RX-V671, into a kill-a-watt meter. At idle, it would consume ~45W. Even when the AVR was set to -30db, it used up ~50W in stereo mode. But crank the volume up to -10db and power consumption went up to 170W at peak with movies. With music, it would consistently stay upwards of 125W in stereo mode. So 125W-45W (for idle), 80W consumed above idle, that is 40W per channel and assuming 60% amp efficiency, that is 24W per speaker. Definitely WAY above your 1 wpc. I can run the tests again with the RX-V773WA.
Quote:
Originally Posted by lovinthehd View Post

Watts aren't chopped up the way you think with simple percentages as the dB scale is logarithmic, plus no idea how you did your measuring. Takes twice as much power (watts) to raise the spl by 3dB, so if you have 100w/ch to gain 3dB you need 200w/ch, to gain another 3dB 400w/ch. Then there's that multi-ch movie sound won't need much from the surrounds, and maybe somewhat more important if you've got multi-ch music recordings. Thinking of what needs to be amplified isn't sine waves used for testing, but rather music and soundtracks, the power demands aren't likely as high as you think. On the other hand, you could literally blow your speakers with too much power, too smile.gif

Are you using a sub? That also helps the avr. I'm just pointing out that amp gives you just a little more advantage in two channels...and if you added a center (as in your other post) then maybe even a 3 ch amp or two pro 2 ch amps (like I am using at the moment, Crown XLS1500s) (didn't finish, so p.s. here....if you need an outboard amp at all.

What is the sensitivity rating of your speakers? Usually you'll get more bang for your buck with more sensitive and more dynamic speakers than start up an amp collection.

Granted, movie audio isn't a continuous sine wave and I understand audio output is on a log scale. But as I said above, I am not sure, how much power can the AVR sustain in 6-channel mode (yes, running two subs, a lowly Yamaha 8" and a Definitive 12" but no center so Front LR, Surrounds + Surround Backs are powered by the AVR).

To be honest, my own conclusion earlier based on the testing and specs was that an external amp isn't required for most home use. See my other thread on the topic here:
http://www.avsforum.com/t/1504252/receiver-amp-ratings-lies-aka-how-to-read-amp-specs

But I wasn't taking into account dynamic range or rather how a single amp (AVR) works on 6-channels across the entire range of DR expected out of it. That is what made me think of an external amp.

While the CSW Tower-1 sound great to me, the spec sheet doesn't have sensitivity numbers frown.gif

Anyways, I went ahead and requested cancellation of my Behringer amp order. I reckon if I add an external amp then at least have the amp potential to match my speakers' rating. Maybe a Crown X2000? smile.gif
post #9 of 30
Quote:
Originally Posted by sjavs View Post


Less than 1watt per channel? You are kidding, right?

smile.gif

No, I'm not kidding. Amplifier power is one of the least important things in home audio. Stop worrying about it. You are being inundated with nonsense.
post #10 of 30
sjavs, think about it, if your speakers have sensitivity of 90 db (for example, your CSWs I suspect are less than that, though)....that's pretty loud with 1 w of power.
post #11 of 30
Quote:
Originally Posted by sjavs View Post

Quote:
Originally Posted by arnyk View Post

+1.

The NU1000 is only rated at 160 wpc / 8 ohms.

The Yamaha RX-V773WA is rated at 95 wpc./ 8 ohms

The RX-V773WA 95 wpc/8ohm is when only two channels are driven. What happens when you drive 6-channels with it?

Please let me tell the whole story:

The RX-V773WA 95 wpc/8ohm is when only two channels are driven with steady pure sine waves into a resistive load.

The answer is: Steady pure sine waves into a resistive load never happens in actual use in your listening room because you have this weird preference for music, or am I speaking falsely for you?

Music has at worst half to 1/4 the energy content of pure sine waves. Real world speakers have average impedance of typically 150% of their specified impedance, while those dummy loads on the test bench have approximately 1/3 lower average impedance.

Put both of these facts together and you've made the typical mid-market AVR into a picture of power supply and heat sink overkill, and I'm not even getting into the rare possibility that one would ever run his receiver continuously just below clipping for any period of time. Most Audiophiles never use but a fraction of the maximum power possible with their AVR. I'm also ignoring the widespread use of smaller speakers for surround speakers because max power never seems to make it there.

You're talking about ACD power (All Channels Driven) which is a controversy, not an accepted scientific fact. While potentially well-intentioned enough, it also has the effect of being a marketing scam favoring the purchase of wildly overbuilt AVRs.
Edited by arnyk - 1/13/14 at 7:11am
post #12 of 30
Quote:
Originally Posted by FMW View Post

Quote:
Originally Posted by sjavs View Post


Less than 1watt per channel? You are kidding, right?

smile.gif

No, I'm not kidding. Amplifier power is one of the least important things in home audio. Stop worrying about it. You are being inundated with nonsense.

Right. Should we tell him about peak SPL calculators such as:

http://myhometheater.homestead.com/splcalculator.html

Here's the game plan:

Meausure your actual peak SPL with a fast responding peak holding SPL meter like this one:

http://www.ebay.com/itm/271167212819?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Then plug the numbers for your actual use of your system into the peak SPL calculator to find out how many watts it takes to do what you actually do.

Report the numbers back to us.
post #13 of 30
Thread Starter 
Quote:
Originally Posted by arnyk View Post

Right. Should we tell him about peak SPL calculators such as:

http://myhometheater.homestead.com/splcalculator.html

Here's the game plan:

Meausure your actual peak SPL with a fast responding peak holding SPL meter like this one:

http://www.ebay.com/itm/271167212819?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Then plug the numbers for your actual use of your system into the peak SPL calculator to find out how many watts it takes to do what you actually do.

Report the numbers back to us.

Yep, had already done that earlier (testing requires me to be home and 20-month old son to not be, so not very easy to test smile.gif )

I have an app on my iphone that measures SPL. As I tested the RX-V671 (with the numbers stated above), with the volume level set to -10db (Yamaha scale is -80db to +16.5db, I think), the SPL meter registered 101db peaks at a distance of about 12 feet.

And, I read all the text here about speaker efficiency, SPL, db, power ratings:
http://www.milbert.com/articles/spl_chart
http://www.musiccenters.com/vol.html

*But*, what I still don't get is where are my watts going? If my AVR power usage went from 45watts (volume set at -40db) to 125W (volume set to -10db), then those 80W were eaten by who? Even with 60% AB amp efficiency, 48W have to end up at the speaker posts. No?
post #14 of 30
Thread Starter 
Quote:
Originally Posted by lovinthehd View Post

(like I am using at the moment, Crown XLS1500s)

Just curious, what's the setup you have with Crown XLS1500? What made you go the external amp route?
post #15 of 30
Quote:
Originally Posted by sjavs View Post

Quote:
Originally Posted by lovinthehd View Post

(like I am using at the moment, Crown XLS1500s)

Just curious, what's the setup you have with Crown XLS1500? What made you go the external amp route?

Because I wanted to retire (at least temporarily) my Carver M500t's (one buzzes and they're quite old altho functional, thought of having them recapped etc) that the Crowns replaced. I also wanted to see what the buzz with pro amps, particularly the D class amps, was about (I think they're solid for the $ compared to the home stuff, don't look as nice but the lower cost rocks). I also listen quite loud and wanted as much headroom as possible so I convinced myself I needed the amps. smile.gif I started measuring my listening levels later smile.gif. I also have a slightly older M500 hanging around from one of my very early systems. I use an Onkyo HTRC370 avr as pre-amp, the Crowns power my L/C/R speakers (one channel going unused), the Onkyo powers the surrounds, this is in a 7 ch setup in the living room. However, the Onkyo by itself would probably be fine most if not all of the time...but who knows what I might want later and always nice to have some extra gear around to use in another room (screw zones).

So where in the city are you? I've lived on Mt Davidson, out in the Richmond and in the Excelsior from '71 thru '08. Just moved up to Oregon from Woodside recently. When I lived in the city I used CSW Ensembles in my first multi-ch setup (still have the sats/center but the little passive subs died).
post #16 of 30
Thread Starter 
Quote:
Originally Posted by lovinthehd View Post

Because I wanted to retire (at least temporarily) my Carver M500t's (one buzzes and they're quite old altho functional, thought of having them recapped etc) that the Crowns replaced. I also wanted to see what the buzz with pro amps, particularly the D class amps, was about (I think they're solid for the $ compared to the home stuff, don't look as nice but the lower cost rocks). I also listen quite loud and wanted as much headroom as possible so I convinced myself I needed the amps. smile.gif I started measuring my listening levels later smile.gif. I also have a slightly older M500 hanging around from one of my very early systems. I use an Onkyo HTRC370 avr as pre-amp, the Crowns power my L/C/R speakers (one channel going unused), the Onkyo powers the surrounds, this is in a 7 ch setup in the living room. However, the Onkyo by itself would probably be fine most if not all of the time...but who knows what I might want later and always nice to have some extra gear around to use in another room (screw zones).

Well, as they say, one who dies with most toys wins tongue.gif
Quote:
So where in the city are you? I've lived on Mt Davidson, out in the Richmond and in the Excelsior from '71 thru '08. Just moved up to Oregon from Woodside recently. When I lived in the city I used CSW Ensembles in my first multi-ch setup (still have the sats/center but the little passive subs died).

Sorry, haven't updated the profile. Used to live in an apartment in the Twin Peaks neighbourhood. After the son was born, we moved down to the peninsula. Have a basement here to setup a nice HT smile.gif
post #17 of 30
My brother used to say that a lot (and he's winning by quite a bit).

I'm missing the good weather on the peninsula....but not missing the cost and the congestion and the other life in the city stuff. A basement in the bay area....lucky you!

Now your question about the power consumption watts as compared to the output wattage....they're not comparable as far as I'm aware but can't explain, over my pay grade wink.gif
post #18 of 30
Thread Starter 
Quote:
Originally Posted by arnyk View Post

Please let me tell the whole story:

The RX-V773WA 95 wpc/8ohm is when only two channels are driven with steady pure sine waves into a resistive load.

The answer is: Steady pure sine waves into a resistive load never happens in actual use in your listening room because you have this weird preference for music, or am I speaking falsely for you?

Music has at worst half to 1/4 the energy content of pure sine waves. Real world speakers have average impedance of typically 150% of their specified impedance, while those dummy loads on the test bench have approximately 1/3 lower average impedance.

Agree, so far, with everything you said.
Quote:
Put both of these facts together and you've made the typical mid-market AVR into a picture of power supply and heat sink overkill, and I'm not even getting into the rare possibility that one would ever run his receiver continuously just below clipping for any period of time. Most Audiophiles never use but a fraction of the maximum power possible with their AVR. I'm also ignoring the widespread use of smaller speakers for surround speakers because max power never seems to make it there.

You're talking about ACD power (All Channels Driven) which is a controversy, not an accepted scientific fact. While potentially well-intentioned enough, it also has the effect of being a marketing scam favoring the purchase of wildly overbuilt AVRs.

This is the part I have trouble agreeing with for two reasons:
1. The power consumed by the AVR test that I did tells me if I set to volume on my Yamaha AVR to -10db in stereo mode, producing ~101db peaks with music, I am using a roughly 1/4 the watts than what the PS on the AVR is rated at (125W out of 480W on the RX-V671). Yes, that is a fraction (roughly 1/4th) but that is only stereo mode and for music. With movies, the story gets a bit complex. While average consumption is low with movies, the peaks are higher that what they are with music for the same audio level set on the AVR (-10db).

So, if I play a movie, say LoTR Return of the King, the section where Frodo & Co are lingering outsides the gates of Mordor, trying to find the pass around into Mordor - plenty of dialogue and sudden bursts of audio. I set my AVR to -10db and put it in Stereo mode. Peak power consumption goes to ~170W. Add two surround speakers and now the peak power consumption goes to ~200W.

As we do these readings, thing to keep in mind, is that I am reading power consumed at the electrical outlet. This reading is an absolute in the sense, this energy has to spent somewhere down the system between the AVR (heat, amplification, digital circuitry etc) and speakers (coil, mechanical movement).

At 200W power consumption, assuming 80% PS efficiency, we are using over 50% of what the PS can handle. I wouldn't say that is a fraction. At 170W power consumption in stereo mode, taking out the idle power use of about ~45W, we have 145W being consumed by the amplifier. Take out a 40% for worst case amp efficiency, and we are delivering ~50W to each speaker in stereo mode. Again, we are above 50% of the rated wpc for each channel in stereo mode. So we are below the limit and have good headroom but I wouldn't call it a fraction.

Obviously, you could produce test data and convince me otherwise smile.gif

2. From the commercial point of view, overbuilding these AVRs doesn't make sense. If 80% of consumers are going to heavily under utilize their AVRs then why spend money making them all that beefier, bigger and heavier? You spend more money on parts, storage, shipping etc etc. As a manufacturer, I would build these AVRs where they fly just under the radar for most use cases so consumers don't complain of poor audio and I don't end up spending $$$ more than I need to on component/manufacturing and other costs. With lots of competition in this arena, I'd bet that is what the manufacturers have done.

Just my 2 cents worth smile.gif As always, show me data otherwise with means to replicate the results (aka a scientific process to test) and I will shut my trap biggrin.gif
post #19 of 30
Thread Starter 
Quote:
Originally Posted by lovinthehd View Post

My brother used to say that a lot (and he's winning by quite a bit).

I'm missing the good weather on the peninsula....but not missing the cost and the congestion and the other life in the city stuff. A basement in the bay area....lucky you!

Yep, I hear you. People outside the bay area look at salaries here and think we must be rolling in money. But taxes in CA and housing prices in the bay area quickly make you a pauper smile.gif Wife and I drove up to Oregon once along CA-1 from SF. Ended up at this small place by the sea called Port Orford. It was labor day weekend and the town had lots of celebrations/dances organized. We met lots of retired folks who moved from the bay area / Sacramento area for precisely the same reasons (1) taxes (2) congestion

The peninsula isn't as warm as the South Bay or East Bay, in fact, we get fog from time to time depending on which city on the peninsula (Pacifica is the worst, while Millbrae onwards towards the south you get no fog, almost). But on the plus side, if you live towards the hills/I-280 then most houses are on a hill-side and you get a faux basement (which is what I have) smile.gif
post #20 of 30
The OP hasn't stated why he wants a larger amp.

Increase SPL? - Get more efficient speakers

Reduce Distortion? - Maybe increase power

A beefier amp with similar distortion specs will sound cleaner since its not driven as hard. Distortion curves typically trend upwards as amplifier load increases until full clipping and distortion skyrockets.

IDK how the berry stacks up to your AVR on distortion but that is the only reason I would be looking at other amps.
post #21 of 30
Quote:
Originally Posted by sjavs View Post


Agree, so far, with everything you said.
Quote:
Put both of these facts together and you've made the typical mid-market AVR into a picture of power supply and heat sink overkill, and I'm not even getting into the rare possibility that one would ever run his receiver continuously just below clipping for any period of time. Most Audiophiles never use but a fraction of the maximum power possible with their AVR. I'm also ignoring the widespread use of smaller speakers for surround speakers because max power never seems to make it there.

You're talking about ACD power (All Channels Driven) which is a controversy, not an accepted scientific fact. While potentially well-intentioned enough, it also has the effect of being a marketing scam favoring the purchase of wildly overbuilt AVRs.

This is the part I have trouble agreeing with for two reasons:
1. The power consumed by the AVR test that I did tells me if I set to volume on my Yamaha AVR to -10db in stereo mode, producing ~101db peaks with music, I am using a roughly 1/4 the watts than what the PS on the AVR is rated at (125W out of 480W on the RX-V671). Yes, that is a fraction (roughly 1/4th) but that is only stereo mode and for music. With movies, the story gets a bit complex. While average consumption is low with movies, the peaks are higher that what they are with music for the same audio level set on the AVR (-10db).

Please describe your AVR test, I am unfamiliar with it and you did not provide a link.
Edited by arnyk - 1/14/14 at 1:32pm
post #22 of 30
Quote:
Originally Posted by arnyk View Post

Quote:
Originally Posted by sjavs View Post


Agree, so far, with everything you said.
Quote:
Put both of these facts together and you've made the typical mid-market AVR into a picture of power supply and heat sink overkill, and I'm not even getting into the rare possibility that one would ever run his receiver continuously just below clipping for any period of time. Most Audiophiles never use but a fraction of the maximum power possible with their AVR. I'm also ignoring the widespread use of smaller speakers for surround speakers because max power never seems to make it there.

You're talking about ACD power (All Channels Driven) which is a controversy, not an accepted scientific fact. While potentially well-intentioned enough, it also has the effect of being a marketing scam favoring the purchase of wildly overbuilt AVRs.

This is the part I have trouble agreeing with for two reasons:
1. The power consumed by the AVR test that I did tells me if I set to volume on my Yamaha AVR to -10db in stereo mode, producing ~101db peaks with music, I am using a roughly 1/4 the watts than what the PS on the AVR is rated at (125W out of 480W on the RX-V671). Yes, that is a fraction (roughly 1/4th) but that is only stereo mode and for music. With movies, the story gets a bit complex. While average consumption is low with movies, the peaks are higher that what they are with music for the same audio level set on the AVR (-10db).

Please describe your AVR test, I am unfamiliar with it and you did not provide a link.

Look at post # 8 and his link to an avs thread where he describes it further....
post #23 of 30
Quote:
Originally Posted by sjavs View Post

Quote:
Originally Posted by lovinthehd View Post

My brother used to say that a lot (and he's winning by quite a bit).

I'm missing the good weather on the peninsula....but not missing the cost and the congestion and the other life in the city stuff. A basement in the bay area....lucky you!

Yep, I hear you. People outside the bay area look at salaries here and think we must be rolling in money. But taxes in CA and housing prices in the bay area quickly make you a pauper smile.gif Wife and I drove up to Oregon once along CA-1 from SF. Ended up at this small place by the sea called Port Orford. It was labor day weekend and the town had lots of celebrations/dances organized. We met lots of retired folks who moved from the bay area / Sacramento area for precisely the same reasons (1) taxes (2) congestion

The peninsula isn't as warm as the South Bay or East Bay, in fact, we get fog from time to time depending on which city on the peninsula (Pacifica is the worst, while Millbrae onwards towards the south you get no fog, almost). But on the plus side, if you live towards the hills/I-280 then most houses are on a hill-side and you get a faux basement (which is what I have) smile.gif

Before I tired of the rat race and quit my job last August I lived up near four corners (the intersection of 84 & 35 (Woodside Rd & Skyline), near Alice's Restaurant), looked over Palo Alto/Portola Valley, generally great weather. Second day after finishing unloading here we got 8 inches of snow! Yep lots of transplants in Oregon....being called a Californian isn't exactly a compliment rolleyes.gif Home prices here where I am (Oakridge) are particularly attractive, the lack of a sales tax is a bonus. smile.gif As long as I'm near good mountain biking I'm happy biggrin.gif
post #24 of 30
Thread Starter 
Quote:
Originally Posted by arnyk View Post

Please describe your AVR test, I am unfamiliar with it and you did not provide a link.

Actually, never mind my earlier test. As with any scientific experiment, you first need to have a working hypo-thesis or design your experiment and agree on it.

So my approach is to measure how much electricity an AVR consumes and work from there to get to how much goes to the speakers. If we agree on the theory then I can run the tests again (and you can too) and we can report number back. That way, everyone involved understands what's going on.

Objective: Find out how much power is delivered to a pair of speakers in a real life listening situation (movie/music) and not sine-wave test (that we all agree isn't too good for imitating real-life listening).

Here's the theory: Measuring power consumption of the AVR at idle and then various level of audio output (as measured in decibels at a certain distance) should tell us how much power is being delivered to the speakers at each audio level. This is because if we deduct the idle level power, call it "L", consumption from the power consumed at a certain "play" level, call it Pn, then that should give us the power being consumed by the amplifier section of the AVR, call it Sn. For a measured audio level in decibels of n, Sn = Pn - L

Reducing the typical efficiency of an AB class amp from that value (60%), should give us what's getting delivered to the speakers. So, (Sn x 0.6)/2 = power delivered to each speaker.

Now, since the power consumed is going to vary with the input signal (or audio track being played), you can observe/note - peaks and rough average (if you are using something like a kill-a-watt meter since you can cannot record each reading).
post #25 of 30
Thread Starter 
Quote:
Originally Posted by NicksHitachi View Post

The OP hasn't stated why he wants a larger amp.

Increase SPL? - Get more efficient speakers

Reduce Distortion? - Maybe increase power

A beefier amp with similar distortion specs will sound cleaner since its not driven as hard. Distortion curves typically trend upwards as amplifier load increases until full clipping and distortion skyrockets.

IDK how the berry stacks up to your AVR on distortion but that is the only reason I would be looking at other amps.

Fair question and to be honest, I am not sure what I am looking for either. I read all these reviews/postings of other users who have added an external amplifier and report the audio as fuller/better/more-detail etc etc. It very well could be that once you spend money on an external amp, your brain tricks you into believing you are hearing better SQ smile.gif Or, maybe there is actually a technical explanation to why people hear improved SQ after adding an external amplifier.

I guess I could get something like a Crown XLS1500 from GuitarCenter, try it out and if doesn't work as advertised then get my money back. However, another issue that has cropped up is about the voltage output of Yamaha AVRs. Lots of postings about Yamaha receivers only putting out 1V which is inadequate to properly drive most power amps (apparently Emotiva's amp have trade-offs that let the Yamaha AVRs work alright with them).
post #26 of 30
Quote:
Originally Posted by sjavs View Post

Quote:
Originally Posted by arnyk View Post

Please describe your AVR test, I am unfamiliar with it and you did not provide a link.

Actually, never mind my earlier test. As with any scientific experiment, you first need to have a working hypo-thesis or design your experiment and agree on it.

So my approach is to measure how much electricity an AVR consumes and work from there to get to how much goes to the speakers. If we agree on the theory then I can run the tests again (and you can too) and we can report number back. That way, everyone involved understands what's going on.

Objective: Find out how much power is delivered to a pair of speakers in a real life listening situation (movie/music) and not sine-wave test (that we all agree isn't too good for imitating real-life listening).

Here's the theory: Measuring power consumption of the AVR at idle and then various level of audio output (as measured in decibels at a certain distance) should tell us how much power is being delivered to the speakers at each audio level. This is because if we deduct the idle level power, call it "L", consumption from the power consumed at a certain "play" level, call it Pn, then that should give us the power being consumed by the amplifier section of the AVR, call it Sn. For a measured audio level in decibels of n, Sn = Pn - L

Reducing the typical efficiency of an AB class amp from that value (60%), should give us what's getting delivered to the speakers. So, (Sn x 0.6)/2 = power delivered to each speaker.

Now, since the power consumed is going to vary with the input signal (or audio track being played), you can observe/note - peaks and rough average (if you are using something like a kill-a-watt meter since you can cannot record each reading).

I have some problems with your methodology but they aren't serious. I appreciate what you have tried to do.

First off the efficiency of a class AB amp is far from constant.

http://sound.westhost.com/efficiency.htm



Secondly acoustic measurements are very imprecise compared to electrical measurement. Assuming reasonably linear speakers is reasonble. Therefore we should compare electrical measurements (watts, volts) for a given reasonable approximate estimated SPL.

classABampefficiency.xls 23k .xls file
post #27 of 30
Thread Starter 
Quote:
Originally Posted by lovinthehd View Post

Watts aren't chopped up the way you think with simple percentages as the dB scale is logarithmic, plus no idea how you did your measuring. Takes twice as much power (watts) to raise the spl by 3dB, so if you have 100w/ch to gain 3dB you need 200w/ch, to gain another 3dB 400w/ch. Then there's that multi-ch movie sound won't need much from the surrounds, and maybe somewhat more important if you've got multi-ch music recordings. Thinking of what needs to be amplified isn't sine waves used for testing, but rather music and soundtracks, the power demands aren't likely as high as you think. On the other hand, you could literally blow your speakers with too much power, too smile.gif

Are you using a sub? That also helps the avr. I'm just pointing out that amp gives you just a little more advantage in two channels...and if you added a center (as in your other post) then maybe even a 3 ch amp or two pro 2 ch amps (like I am using at the moment, Crown XLS1500s) (didn't finish, so p.s. here....if you need an outboard amp at all.

What is the sensitivity rating of your speakers? Usually you'll get more bang for your buck with more sensitive and more dynamic speakers than start up an amp collection.

Thought I'd update the thread. While I haven't had time to experiment more scientifically and post, curiosity got the better of me and I did end up getting a Crown XLS 1500 to drive front L/R. So far, haven't turned up the volume a whole lot but can't really tell the difference between using an external amp vs using the AVR to drive those two speakers. The amp itself is nice - light weight, easy to use and no fan noise.
post #28 of 30
Congrats, or is this still on trial as far as keeping it goes? Curious, how did you set gain on the amp?

Still got summer like weather down there? Still mild and scary dry here.
post #29 of 30
Two weeks ago, I went to a local cinema in the UAE. I asked the technician who's Indian to let me see their control room. I was just curious to see what they have in their commercial cinema. The guy agreed and let me see it. Beside the Christie projector and its aux and the Dolby processor, everything else was Crown XLS 2000 and DSi. There were two stacks of them.
post #30 of 30
Thread Starter 
Quote:
Originally Posted by lovinthehd View Post

Congrats, or is this still on trial as far as keeping it goes? Curious, how did you set gain on the amp?

Keeping the XLS1500. I am running an experiment with dual centers so pretty handy to have an external amp smile.gif

Still got summer like weather down there? Still mild and scary dry here.[/quote]

Yeah, still pretty bad actually despite 4-5 days of consistent rain - we are still, I think, at 30% of the average annual precipitation.

Quote:
Originally Posted by Plagen View Post

Two weeks ago, I went to a local cinema in the UAE. I asked the technician who's Indian to let me see their control room. I was just curious to see what they have in their commercial cinema. The guy agreed and let me see it. Beside the Christie projector and its aux and the Dolby processor, everything else was Crown XLS 2000 and DSi. There were two stacks of them.

Thanks, good data point.
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