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View Full Version : Could someone please help explain the benefit of an Amplifier



Harro
11-13-2013, 08:00 AM
Please bear with me as I am just starting on this trip called an audio maze.

I currently am running a Denon 4311Ci for my 340's F/C/R and 170's for a 9.2 set up. Everything sounds great but seems that my AVR runs somewhat hot. With me thinking about going to a 11.2 in the future I will need an amp but have been thinking about how to go about getting what I need and still take some of the burden off of the AVR for the power. So I know I need at least a 2 channel to run the additional 2 speakers high but what if I got a 5 channel and then used 5 channels on the AVR for the others? Same thought on a 7 channel Amp. I am lost. I really could use some people that have gone through this for some advise and thoughts.

I am also looking at the future to upgrade to different Ascends, maybe towers and a new center and want to get the best from everything with all things considered as to what to power them with cleanly.

Thank you

Kisakuku
11-13-2013, 09:13 AM
Please bear with me as I am just starting on this trip called an audio maze.

I currently am running a Denon 4311Ci for my 340's F/C/R and 170's for a 9.2 set up. Everything sounds great but seems that my AVR runs somewhat hot. With me thinking about going to a 11.2 in the future I will need an amp but have been thinking about how to go about getting what I need and still take some of the burden off of the AVR for the power. So I know I need at least a 2 channel to run the additional 2 speakers high but what if I got a 5 channel and then used 5 channels on the AVR for the others? Same thought on a 7 channel Amp. I am lost. I really could use some people that have gone through this for some advise and thoughts.

I am also looking at the future to upgrade to different Ascends, maybe towers and a new center and want to get the best from everything with all things considered as to what to power them with cleanly.

Thank you

You could either get a cheap 2-channel amp to run the two extra channels for 11.2 or a beefy 2(or 3)-channel amp to run the fronts (or fronts/center). The rest can be easily powered by 4311, so no need to splurge for an amp with more channels than you need.

4311 runs reasonably cool, but you can always use some quiet USB-powered fans for ventilation. I have two 18cm low RPM fans lying flat on its top surface and blowing up.

Dark Ranger
11-13-2013, 11:11 AM
Hi Harro,

I agree with Kisakuku's suggestion about using a fan to help remove heat from your AVR. This will keep the AVR cooler no matter the load and can possibly help with component longevity.

The primary benefits of using an external amplifier are additional power handling, current capacity, and greater dynamic headroom. (External amplifiers are also required if one is using a dedicated "separate" preamplifier or processor. The amps are not built in to these standalone components.) AV Receivers are designed as an all-in-one solution. The chassis must accommodate circuitry for audio and video processing, plus amplification for the 5, 7, or 9+ speaker channels. There's only so much room to go around, plus the inherent heat issues that come with stuffing huge power supplies into an AVR chassis.

External power amplifiers don't have this limitation, therefore the power handling is usually much greater. Some external amplifiers are very large and heavy, and can offer several hundred watts to well over a kilowatt of power for speakers. You don't need to go that crazy to benefit from a good external amp. Even something in the 150-200 watt range is usually "plenty" for reasonable volume levels in typical configurations.

So getting back to your system: at a minimum, a 2-channel amplifier for Front Left/Right would take much of the burden away from the AVR. The Front Left/Right channels reproduce the majority of soundtracks these days, and of course 100% of stereo-format music. The AVR should be able to handle the rest of the speakers (even with your proposed 11.2 setup). The surrounds/heights/wides do not require constant power, unlike the fronts. So a 2-channel amp would be the easiest and simplest way to get started. However, a 3-channel amplifier would take all three front speakers (LCR), arguably the most important, and offload them to an external amplifier. You'd also get the benefit of ensuring identical power and sound characteristics for the LCR speakers.

Your AVR is pretty stout, so it won't have any issues driving the remaining speakers once the L/R or LCR are offloaded. Your AVR may run a little cooler, too. In your case, I don't believe a 5+ channel amplifier would be needed.

My two cents. :)



Also, can you clarify why you need an external amp for the 9.2 --> 11.2 upgrade? I don't own this receiver. The Denon's rear panel (http://usa.denon.com/Assets/images/products/AVR-4311CI/EL_AVR-4311CI_back.png) appears to support the following channels:

Front Left/Right
Center
Surround
Back Surround
Front Height
Front Wide

That's 11 channels. Have you assigned one of these as a zone instead? Unless I'm misunderstanding something, it seems you could theoretically power all 11 speakers from the AVR. I know some AVRs (I'm thinking of Onkyo here) absolutely require an external amplifier when using a matrixed channel like Heights or Wides. There is no actual output and binding post on the receiver's back panel. It's only a pre-out to an external amp. Your Denon does not seem to have this restriction.

Again, if I'm misunderstanding your setup, please clarify.

Kisakuku
11-13-2013, 12:03 PM
Again, if I'm misunderstanding your setup, please clarify.

4311 has 9 amps, so it requires an external 2-channel amp for 11.1/11.2.

Harro
11-13-2013, 01:02 PM
Wow thanks guys I am starting to understand this little by little with everyone's Great Help.
The manual states that that going to 11.2 requires an external amp to be connected to the pre out connector.
Now if I got a 5 channel amp could in theory I run the 3 front channels and also the 2 heights? That would or should take the stress from the AVR keeping it cooler?

natetg57
11-13-2013, 01:25 PM
Now if I got a 5 channel amp could in theory I run the 3 front channels and also the 2 heights? That would or should take the stress from the AVR keeping it cooler?

That should work. What the consensus seems to be is to just get a 3 channel amp and run the remaining 8 channels off of the AVR.

petmotel
11-13-2013, 01:35 PM
Wow thanks guys I am starting to understand this little by little with everyone's Great Help.
The manual states that that going to 11.2 requires an external amp to be connected to the pre out connector.
Now if I got a 5 channel amp could in theory I run the 3 front channels and also the 2 heights? That would or should take the stress from the AVR keeping it cooler?

You've had two good responses now both of which suggested that a two, or three channel amp powering either the front mains, or the front mains, and center would take a great deal of the load off of your receiver. This is VERY good advice. However, if you feel a need for some reason to power the two required additional channels and all the rest with external amps, it won't hurt a thing. Overkill no doubt, but it appears like you want to add 5 channels of external amplification. Same deal, overkill but it will work fine.

The front mains, and in movies the center channel also, handle the lions share of the audio load, so offloading their share from the receiver would reduce it's current needs substantially at higher volumes.

This would be my suggestion as well, you can get a better two or three channel amp that will cost less, will be smaller, and lighter than a five channel. Those can get pretty darn hefty, and large if you buy something with a good amount of power.

Jay

edit: sorry Nate, three good replies!

Kisakuku
11-13-2013, 01:50 PM
Now if I got a 5 channel amp could in theory I run the 3 front channels and also the 2 heights? That would or should take the stress from the AVR keeping it cooler?

Yes, you could do that, but I'm not sure it makes the most sense. You could get a more powerful 2- or 3-channel amp for the same price. 4311 has very robust built-in amps, so unless you know they are somehow limiting you, getting extra channels of external amplification might not be the best use of your budget. If heat build-up is your main concern, active cooling would cost you $50 at most.

Harro
11-13-2013, 02:10 PM
I just ran through the set up on the AVR and if I assign it to 11 channel it will then prompt me for either the heights or the fronts (L/R) to amp. So after reading all your replies , my thought would be to go to a 2 channel amp and amp the fronts. Thus giving me the heights on the rear of the AVR powered. This will be the most cost effective for now. After I have this all set up and still feel the need for cooling the AVR, I 'll just get a laptop cooler or something similar to place on the top.
Thanks again for all the replies and helping me learn and understand about all this. Sometimes reading the manuals seems like it could be in Chinese cause I just don't get what they are trying to tell me. But you guys explain it so simple . Thanks

Dark Ranger
11-13-2013, 02:37 PM
4311 has 9 amps, so it requires an external 2-channel amp for 11.1/11.2.

Ah, I see. Thanks for the explanation. The 11 sets of binding posts threw me, so I figured there were 11 amps.


Wow thanks guys I am starting to understand this little by little with everyone's Great Help.
The manual states that that going to 11.2 requires an external amp to be connected to the pre out connector.
Now if I got a 5 channel amp could in theory I run the 3 front channels and also the 2 heights? That would or should take the stress from the AVR keeping it cooler?

I just finished looking through the AVR manual. You can certainly use an external amplifier for the Front Heights, leaving the remaining 9 speakers connected to the AVR. Some folks may prefer this. However, I think I'd much rather use an external amplifier for more critical channels, such as the FL & FR.

The manual states (page 64) that you can task the "Ext. Amp/PRE OUT" function for either the Height or Front to enable an 11.1/11.2 configuration:

--------------------------
Use ▼ to select “Ext. Amp”, and use ◄► to select the PRE OUT connector to which an external power amplifier is connected.

Height
Select the Height setting to connect an external power amplifier to the front height (FHL/FHR) terminals of PRE OUT connector for playback.

Front
Select the Front setting to connect an external power amplifier to the front (FL/FR) terminals of PRE OUT connector for playback.
--------------------------

This will allow you to use an external amp for the FL/FR while keeping the rest of your speakers connected to the AVR. In addition, you can now run the Height channels off the AVR.

I believe this is an accurate interpretation of the manual. Again, I don't own a 4311CI, so I cannot validate this. Kisakuku can correct me if I'm wrong. :)



EDIT: Harro replied while I was typing up my response. And I got tied up in a phone call. I think you're on the right track.

petmotel
11-13-2013, 02:53 PM
So this receiver is not able to be configured for pre outs to external amplifiers for any channels you might want? As I don't own this model, I will have to defer to someone familiar with it, I just figured you could use the pre-outs for any channels. Never seen it any other way.

Jay

Edit: OP, just curious, as you're going with an 11.1 configuration, are you planning on acoustic treatments in your room?

Dark Ranger
11-13-2013, 03:05 PM
The configuration I mentioned only applies in an 11.1/11.2 channel system since the AVR-4311CI has 9 amplifier circuits. Otherwise, the AVR offers pre-outs for all channels as well as an optional "preamp only" mode. :)

Kisakuku
11-13-2013, 03:41 PM
I just ran through the set up on the AVR and if I assign it to 11 channel it will then prompt me for either the heights or the fronts (L/R) to amp. So after reading all your replies , my thought would be to go to a 2 channel amp and amp the fronts. Thus giving me the heights on the rear of the AVR powered. This will be the most cost effective for now. After I have this all set up and still feel the need for cooling the AVR, I 'll just get a laptop cooler or something similar to place on the top.
Thanks again for all the replies and helping me learn and understand about all this. Sometimes reading the manuals seems like it could be in Chinese cause I just don't get what they are trying to tell me. But you guys explain it so simple . Thanks

The most cost-effective solution would still be to get a cheap 2-channel amp for the heights, but it's a much less exciting purchase and a bit of a dead end in terms of the upgrade path.

The Denon manuals are indeed very cryptic, but Batpig's site (http://batpigworld.com/wp/) and the 4311 AVS thread (http://www.avsforum.com/t/1274153/) are great resources.

Harro
11-13-2013, 03:44 PM
What dark ranger said about the preamp is correct. If I choose preamp then all speaker connects are non functioning.
As for room treatments, that may come in the future but I have limited amount of space. Room dimensions are 13.4x16.4x8, with a matching leather couch and loveseat along with snack bar and 4 slot machines. So space is very limited. 1 door opening in the center of the 16.4 wall and opposite side has a 9.5 width window. The window would be the one spot I will be considering for a treatment. Will be ordering a SVS PC12+ before the end of the year to complement my PB12+.
I love this hobby but it sure is costly. hehe

natetg57
11-13-2013, 05:37 PM
So this receiver is not able to be configured for pre outs to external amplifiers for any channels you might want? As I don't own this model, I will have to defer to someone familiar with it, I just figured you could use the pre-outs for any channels. Never seen it any other way.


According to this paragraph from AVS you can

Which possible combinations of internal and external amps are there?
- You can have ANY combination of internal and external amps. You can power 5 speakers with external amps and 4 with internal... you can power 3 with external and 8 with internal.... you can power 2 with external and 9 with internal.... 9 with external and 2 with internal.... IT'S ALL GOOD. The ONLY thing you can't do is power 11 speakers internally...... because there are only 9 amps built in!

- The ONLY exception is that, because the receiver only has 9 amps built in, when you activate 11 channel mode, the receiver forces you to choose whether the FIRST TWO extra channels will be the heights or the front L/R mains.

petmotel
11-13-2013, 07:37 PM
According to this paragraph from AVS you can

Thanks for clearing that up. Makes sense, if you were using a wimpy, cheap amp you'd want to use the heights, If you have a more stout solution, you'd want to power the mains with it.

Jay