Receiver or Receiver+Amp Recommendation

[keyboarder]

Please help recommend receiver or receiver/amp combo.

Considering these options for a 16x16ft room where I will never be cranking to ear bleeding levels. Music sound quality is top priority, movies second, high volume is not important to me so big power might not be as critical.

1 - Upgrade to HDMI Receiver and Keep Amps as shown
2 - Upgrade to HDMI Receiver and sell amps to buy a 5 Channel Amp (Emotiva XPA5, Parasound, etc.)
3 - Upgrade to HDMI Receiver model with enough power to push my speakers.
4 - Upgrade to HDMI Receiver, run center and rears off of receiver, run Fronts off of Denon POA-2400 since the fronts are more power hungry than the others.

*Must support Audyssey, I love the idea of the receiver leveling all speakers correctly and adjusting for room acoustics. Just awesome.
*Must stream network media (though I can do that via Oppo BPD-93)

Are Denon 4310CI's 130WPC or 4311CI's 140WPC Enough to do these KEF's justice? I'd love to throw down for a big TOTL receiver but it's not possible. Under $1k is desired, but could consider $1500 street price of the 4311CI.

This is what I have now, the Denon 3803 has been a great receiver but it's time to upgrade.

I love this forum.

 

[shelly_d]

Not sure why you need to upgrade. You seem to have plenty of power available for you room size.

The POA-2400 can drive the 89 dB KEF's to peak levels of 109 dB and still have 3 dB headroom left over before clipping.

The POA-1500 can get your 89 dB rear speakers up to 108 dB under the same conditions, that is 3 dB headroom available. It will drive to the same level as the front speakers (109 dB) but then you have only 2 dB of headroom.

Your center setup appears to have a total of 300 watts driving your center speakers. If I understand that correctly, you can get that puppy up to 110 dB with 3 dB of headroom.

Assuming you want to keep everything balanced, you can get 5 speakers up to 108 dB each in a 16 by 16 room without clipping on any of your amps. That is LOUD!

So what are you looking for?, Trying to achieve that you don't have now?

I'm lost.

Shelly_D

Looked again at your post. 130 watts will get 89 dB speakers to 107 dB peaks with 3 dB headroom to spare. Probably enough.

Shelly_D

 

[shelly_d]

Just ran the same numbers on the 110 watt/channel receiver and you will get 106 dB out of them with 3 dB headroom.

Shelly_D

 

[keyboarder]

Thank you for the input.

If I could get a receiver that has HDMI and Audyssey and enough power to do it all without extra amps, I could sell my amps to help pay for it. But I don't want to lose any sound quality by "cheaping out" on receiver/amp department when I've invested so much in good speakers.

I have wondered if the non-matching amps mattered and if I would be better off going to a single 5 channel... or if I even need big amps at all, given that the receivers I am considering are 130-140W per channel.

 

[keyboarder]

Also, how did you come up with the numbers above, especially for the room size?

 

[240sx4u]

If you can live without HDMI I would be looking at replacing that denon with a krell showcase or something of that nature. Non hdmi switching preamps are rediculously good deals on A'gon if you can live without hdmi.

 

[keyboarder]

For a while I was considering a Denon 5803 that's non-HDMI previous Denon Flagship AVR and they go for around $700 but I just got an Oppo BPD-93 and want to get a decent TV and HDMI seems to be a requirement to get the most out of Bluray.

 

[keyboarder]

Is there a pre out there with all the funcitonality of the Denons I mentioned that is cheaper due to lack of amps?

I have been under the impression that Preamps that can compare favorably with fully featured receivers like the Denon AVR-4311CI are more money, so I haven't even bothered researching preamps as an option.

 

[shelly_d]

Also, how did you come up with the numbers above, especially for the room size?

Each of those numbers is at one meter distance from the speakers, i.e. about 3 ft. In a 16 x 16 foot room you are never more then 8 feet away from any one speaker or little more then 2 meters. The approximation using the one meter numbers is very close to what you will experience. Now how to derive the numbers:

The sensitivity of each speaker is the starting point. That is, each speaker will produce a signal of 89 dB when fed a 1 watt signal. Therefore the task is to find out how many additional dB the amp can feed it, based upon the output power it produces. For that, use the definition of the dB. That is:

dB = 10 * log (output power / reference power)

In this case the reference power is always 1 watt cause that's what the speakers are spec'ed at. So the denominator of the fraction is always 1. That makes the division real simple. The output power is simply the power the amp can produce into speakers of that impedance. So if the amp produces 110 watts the equation becomes:

dB = 10 * log (110/1)

The numbers inside the parentheses reduce to simply 110:

dB = 10 * log (110)

Now comes the hard part, finding and using the Windows scientific calculator that every version of windows has had since Windows 3.0. Open up the simple calculator and then click on view in the menu bar and then select scientific. Once you have entered the number 110 click on the log key (see attached screen shot). You will get the number 2.041392685158225040750199971243. Far more places then you could possible use - buts that Windows for you. Multiply that number by 10. This gives you 20.4. That's how many more dB the amp can add to the sound level over and above 1 watt at clipping. Since we don't want to drive our amps into clipping subtract 3 dB from that as a point where we will voluntarily stop pushing the volume control. This gives us 20.4 - 3 = 17.4 dB. Now add this number to the 89 dB the speaker is spec'ed at:

89 + 17.4 = 106.4 dB with 3 dB headroom.

Note that this is for the peak loudness in the program source.

Hope this helps.

Shelly_D

 

[keyboarder]

I had to read that quite a few times to get it, but I got it now! Thank you!

So a 110W amp will do 106.4dB without clipping (3dB headroom)
A 220W amp will do 109.4dB <edited> without clipping (3dB headroom)

Other than clipping, does more power have any affect below that point? So for normal listening levels would I even benefit from an extra 100W if I'm not using that extra 6dB?

I've read some writings by Bob Carver in the past justifying loads of power but now I'm not so sure it matters in my situation.

 

[240sx4u]

yeah, standalone processors are generally pretty expensive but I would consider keeping an eye out for a deal anyway!

 

[keyboarder]

Emotiva UMC-1 is $800 + 5x200W XPA5 $900 is $1700. Used you could get these below $1500 so the street price is comparable to a Denon 4311CI with more power and separate pre/amps but from what I've read the UMC-1's Emo-Q isn't as good as Audyssey.

I don't care so much about movies, but the idea of using a mic to dynamically adjust sound levels to balance out all of my speakers perfectly is just amazing to me. I'm really trying to gear up for the Pink Floyd Immersion releases later this year so 5.1 audio is my focus on upgrading my receiver.

 

[shelly_d]

I had to read that quite a few times to get it, but I got it now! Thank you!

So a 110W amp will do 106.4dB without clipping (3dB headroom)
A 220W amp will do 112.4dB without clipping (3dB headroom)

Other than clipping, does more power have any affect below that point? So for normal listening levels would I even benefit from an extra 100W if I'm not using that extra 6dB?

I've read some writings by Bob Carver in the past justifying loads of power but now I'm not so sure it matters in my situation.

Long ago a friend and I both observed that some speakers seem to "open up" and sound better on higher power. It wasn't until many years later that I learned all about decibels and how to calculate them. Looking back I'm not exactly sure why we had that observation but I will hazard a guess now. Mind you it's only a guess.

At the time, we were both running systems with somewhat limited power. The amps were good but not top of the line. What I suspect was happening is that as we went louder, we pushed the amp harder and distortion started to creep up. It may have been that the loudest peaks approached the clipping level too closely and increased distortion. We may have heard that without identifying it as distortion. When listened to on an amp with more power that factor went away and the sound cleaned up considerably, making the speakers sound better.

Understand that the sound levels are for PEAKS not average. If we assume that a good recording has peaks that are 10 dB above average, that means that at 106 dB peaks, the average level is down at 96 dB. That 10 dB is perceived by us humans as half as loud. That's just the way we are built. Also, when we perceive volume its as average level, not peak so we need to keep that in mind as we set the volume control. So, in answer to your question, if you like to push the volume, (and sometimes I do) then there is value to more power. It gives you that extra headroom that can keep the amp away from its elevating distortion levels, giving you a cleaner sounding system at your preferred listening levels. The only way to know before hand is to test the system with calibrated instruments.

Radio shack has a not too expensive sound level meter.

http://www.radioshack.com/product/index.jsp?productId=2103667

Using that and a voltmeter and a little math you can figure out how much power you are pumping through your speakers for the volume your are listening at.

Using the sound level meter, turn up the volume to where you like it and take a reading. That will be your average reading.

Put the voltmeter across the speakers and take an AC voltage reading. It's going to keep changing all over the place so try to find the average number. Perhaps the meter has a peak reading, if so use that.

Use the number on the voltmeter to figure out the power you are drawing. The calculation is:

(Voltage squared) / speaker impedance.

So if you measured say 3.4 Volts the calculation for an 8 ohm speaker would be:

3.4 * 3.4 / 8 = 1.45 watts.

Now if you had the peak number, multiply that by 3 for your minimum power need. If its average (which is why I chose only 3.4V for the example) multiply by 20. Yes I did say 20. so in this case you would need an amp of at least 30 watts per channel to avoid clipping.

To show you how power can escalate drastically however, lets say you measured 5.1 Volts:

5.1 * 5.1 / 8 = 3.25 watts

Multiply that by 20 you now get 65 watts. A 50% increase in voltage more then doubled your power needs.

To put more perspective on power needs, a small increase of volume (3 dB) doubles your power requirements. That is why a monster 400 watt per channel amp sounds only a bit louder then a 200 watt per channel amp on the same speakers - it only has 3 dB more power to bring to the party. It does however bring us back to your question of whether more power can make your system sound better. If the peaks in your source material brings the amp close to clipping, more power will avoid that at the same volume and make it sound better.

By the way, now that I've gotten through all that, the sound meeter is not much use beyond letting you know how loud you like it. The same calculations can be done without the sound meter.

Beware however of drawing too fine a line with the voltmeter calculation. Real music or movies have a VERY fast changing signal and the voltmeter can't really keep up with it. Therefore you will probably get number that are lower then you need. so if you see numbers that work out to 20 or 30 watts, don't think you can decrease power, if on the other hand you start to see numbers that push past half the power of your amps, then it could very well be you need to upgrade.

Good Luck

Shelly_D

 

[shelly_d]

I had to read that quite a few times to get it, but I got it now! Thank you!

So a 110W amp will do 106.4dB without clipping (3dB headroom)
A 220W amp will do 112.4dB without clipping (3dB headroom)

Other than clipping, does more power have any affect below that point? So for normal listening levels would I even benefit from an extra 100W if I'm not using that extra 6dB?

I've read some writings by Bob Carver in the past justifying loads of power but now I'm not so sure it matters in my situation.

Correction:

220 Watts will give you 112.4 dB AT clipping, 109.4 dB with 3 dB headroom

Shelly_D

 

[shelly_d]

... Since we don't want to drive our amps into clipping subtract 3 dB from that as a point where we will voluntarily stop pushing the volume control. This gives us 20.4 - 3 = 17.4 dB. ...

You may have missed this in the clutter of my post.

Shelly_D

 

[keyboarder]

Thanks a ton, this is great information. I have a multimeter, so I'll give it a shot.

 

[keyboarder]

After doing some more research I think I might get the Pioneer SC-37. It's 140W amps are very well rated and it has all of the features I had hoped for in the Denon 4311CI but it's cheaper, supposedly better build quality and AMPs. A bonus is I can control it with my iPhone.

 

[uofmtiger]

The 4311ci can also be controlled with an iPhone and works with AirPlay. It also has Audyssey's MultEQ XT 32 room correction. I am not saying it is better than the Pioneer for your purposes, though.

 

[keyboarder]

I didn't realize that. Using an iphone opens up possibilities of running a second zone of speakers on a different floor of my house and controlling it via iPhone over Wifi.

 

[uofmtiger]

There is a Denon app or you can log into the receiver's Internet address on your network. AirPlay is pretty awesome because you can open Pandora or another audio app and it will turn on the receiver and play music while letting you control volume from the app.

The Denon also has Pandora and other Internet sources available without using AirPlay.