When to Add External Amplification to an A/V Receiver

[RXP]

Thanks Peng, didn't realise it'd be potentially risky. Appreciate all your input!

The RXV2700 I was going by the audioholics bench test which had 4 channels driven at 90w a channel. Taking into account the crossover design having an impact - is it better to just run the amp as 2 channel given that it can deliver 171w into the speaker? I was planning on bi-amping to get more power but even at the 90w a channel figure it's not much more so might as well run 2 channel?

 

[PENG]

is it better to just run the amp as 2 channel given that it can deliver 171w into the speaker? I was planning on bi-amping to get more power but even at the 90w a channel figure it's not much more so might as well run 2 channel?

Bi-amping in such way would seem like pointless. Once you remove the jumpers at the 803's terminals the crossover is split into two parts such that the groups of drivers will be fed by two different amps. The effects of having the bass signals mostly confined in a separate pair of wires are believed (I assume by most people who claimed to be experts) to be not audible.

On the power side of the equation, since the demands of the two separated groups of drivers will not be peaking simultaneously all the time, the amplifiers load will be reduced somewhat most of the time. That may result in overall lower THD and a little more dynamic headroom, but again, depending on other factors, such theoretical benefits may not have audible effects. On the other hand, if you have wires to spare and time to kill, there is no harm trying.

 

[lovinthehd]

Thanks Peng, didn't realise it'd be potentially risky. Appreciate all your input!

The RXV2700 I was going by the audioholics bench test which had 4 channels driven at 90w a channel. Taking into account the crossover design having an impact - is it better to just run the amp as 2 channel given that it can deliver 171w into the speaker? I was planning on bi-amping to get more power but even at the 90w a channel figure it's not much more so might as well run 2 channel?

How do you figure passive bi-amping will be more power? I wouldn't bother, it's marketing mostly.

 

[RXP]

Thought I'd report back in - I've finally got everything setup. Trying to fit a second reciever with the 838 was a pain in my black glass cabinet. At first I took the feet off the Yamaha but after feeling how hot the Onkyo got I had a second thought - place it on a separate rack in another room.

I use chrome wire shelving - great for ventilation and they already house my server/networking infrastructure. But it was a hell of a cabling project to get all the speakers terminated into another room.

I'm using pure-direct mode on the Yamaha and I've programmed my harmony to select pure direct after it switches on the Yam.

Can I hear the difference? I don't think so - but Placebo feels better for me knowing that a separate amp is driving he fronts - especially as I eventually move to 5.1.4.

Thanks for everyone's comments - especially Peng.

 

[Matt Thumann]

On this topic I could use some input.
I am trying to maximize my current Pioneer 918-vsx AV receiver's amps as well. I prefer 2 channel sound sound with sub. So no use for center or surrounds. But I am driving Dalquist ca2/w2 towers 6ohms that are very power hungry. Pioneer AV power is weak and I get zero bass.
I had an old 95" era Nakamechi RE-1 2 channel 80W into 8ohms receiver that I though I could add. As my Pioneer 918 lacks pre outs I used a speaker to line level adapter out of the Pioneer's B speaker terminals and fed signal into an aux port on the Nak. Volume is controlled by Pioneer but I cant figure where to permanently set the nak volume? The adapter does have left/right mini screw adjustors that i have max level(turned fully to right).
The Pioneer now drives the CA2 portion of the tower and the Nakamechi is powering the W2's(woofer bases)
I feed the nak signal to just the speaker posts for woofer. leaving c2 module post on woofer bass and no metal connects bewteen the posts as I want just bass cones driven here. The Ca2 "top" speaker is biwired to both ca2 and woofer speaker posts.
My issue is that I have no idea how high I can set the Nakamechi volume control. Or if i need a crossover somewhere in the chain? It definitely effects the sound but I dont want to burn out the amp or just add ill timed signals from two different amps!. The Pioneers master volume works fine controlling the total volume but I want max efficiency out of both units until I can upgrade.
Is this nuts? I just want best sound I get get NOW. thoughts anyone?

 

[TheMirage]

So help me understand. Adding a amplifier for the LCR will not have any noticeable impact until volume reaches levels the AVR would normally cut off?

Project Setup
5.2.4

Marantz 7010
SVS Ultra Towers
SVS Ultra Center
SVS Surrounds
Klipsch 3650s (4 ceiling Atmos)
SVS PC13Ultra (dual)

Plan is add the Gen 3 Emotiva XPA 3 to provide additional power to LCR while taking load off the AVR so it can squeeze a bit more to the other 6 speakers it's running.

 

[RichB]

So help me understand. Adding a amplifier for the LCR will not have any noticeable impact until volume reaches levels the AVR would normally cut off?

Project Setup
5.2.4

Marantz 7010
SVS Ultra Towers
SVS Ultra Center
SVS Surrounds
Klipsch 3650s (4 ceiling Atmos)
SVS PC13Ultra (dual)

Plan is add the Gen 3 Emotiva XPA 3 to provide additional power to LCR while taking load off the AVR so it can squeeze a bit more to the other 6 speakers it's running.

It is not easy to know when a receiver is not properly driving a speaker. For exampele, a momentary bass note may not be properly produced into your speaker load. Will you know it if it is not there

This is clipping/limiting but not what most would call distortion. IMO, the addition of the XPA-3 is good plan

- Rich

 

[TheMirage]

I honestly wouldn't know coming from years of box speaker and receiver kits. I'm making the investment to make sure I get the most out of the system. Also I finally have WAF on the budget

Is it an accurate statement that amplification generally has less value in the sounds and atmos speakers?

Down the road I can send the XPA back for additional channels.

 

[Swerd]

So help me understand. Adding a amplifier for the LCR will not have any noticeable impact until volume reaches levels the AVR would normally cut off?

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

At first I couldn't say I noticed anything had changed. But soon I noticed that the speaker's bass 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 the cues for sound that was comfortably loud and too loud had changed. I could listen at louder levels without noticing that it was uncomfortably loud. After that, I started turning it down.

Apparently, with the AVR I had judged when to turn it down by the amount of noise or distortion I was hearing. When I started using the bigger amp, those cues were less noticeable. It's not unlike driving a car, where I could estimate my speed by listening to the 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 at the same time, driving the speakers louder.

I hope that makes sense.

 

[Fritz]

heres my answer to that question. Right or wrong its my money and if thats what I want to do Ill do it! LOL

 

[lovinthehd]

So help me understand. Adding a amplifier for the LCR will not have any noticeable impact until volume reaches levels the AVR would normally cut off?

Project Setup
5.2.4

Marantz 7010
SVS Ultra Towers
SVS Ultra Center
SVS Surrounds
Klipsch 3650s (4 ceiling Atmos)
SVS PC13Ultra (dual)

Plan is add the Gen 3 Emotiva XPA 3 to provide additional power to LCR while taking load off the AVR so it can squeeze a bit more to the other 6 speakers it's running.

Well, your avr doesn't really cut off....but I think using an external amp does depend where you like to twist the volume dial to to a great extent.

I used hefty power amps on my main setup for years as I had originally been sold on the idea for a few of the usual reasons/sales pitches, but I used to play at significantly higher volumes, too. Now I'm just using my avr (altho my current avr amp section is significantly more powerful than the avrs I'd used before), and now rarely go above -10 these days (being nicer to my hearing these days); the avr also doesn't do the heavy lifting, my subs do that, so the load on the avr amps is further reduced. Saving a bit of heat in an avr isn't a bad thing, tho. YMMV as to how much benefit you'll find in a power amp.

FWIW a few years ago I started experimenting with Crown XLS amps to both see what the fuss about pro amps was and also with the idea of eventually at least using them for some diy subs after I refurbished my older amps. I used those on my mains for quite a while before I got around to doing the diy subs and was very happy with them. If I were amp shopping now that's what I'd get over the Emotiva (and in a sense I did, as I was also considering Emotiva at the time).

 

[nunnas]

am i mad or do others think like this
more power is good
im currently running a Yamaha av receiver rxa1010 into a pair of NAD 216 running as mono blocks into Klipsch reference rf82'2s. the Yamaha also drives Klipsch rc62'2 center, rs52'2 surrounds and a sw112 sub. the power outputs are Yamaha 110w per channel and the NADs are 400w each sub is 300w, the first question is, is this enough power and 2, would anyone have a idea why when i turned it up to +2 on the amp (goes to +16) the Yamaha cut out at the time a db meter on a smart phone was reading 122db

 

[lovinthehd]

The watts by themselves are meaningless as a measure of what is sufficient power. Unused power is a waste, too. Maybe you could use an spl calculator to help see the relationship between distance and speaker sensitivity and watts. +2 is a pretty high demand, 122 dB is very loud; sounds like the Yamaha's self protection circuits kicked in and shut the unit down. If you really want these kind of sound levels you may need external amps for all channels but really you're more likely to be hitting the speakers' limits and risking damage to them and your ears in this range anyways.

 

[nunnas]

ok, cool thanks yeh its happy at 0 on the amp and thats about 120db on the same phone meter and is happy there so i think ill leave it at that as a max setting as it is crazy loud but still sounds clear. the spl calculator gave me 134db at full volume but it just doesn't seem correct to me 125 sounds more reasonable.

 

[PENG]

ok, cool thanks yeh its happy at 0 on the amp and thats about 120db on the same phone meter and is happy there so i think ill leave it at that as a max setting as it is crazy loud but still sounds clear. the spl calculator gave me 134db at full volume but it just doesn't seem correct to me 125 sounds more reasonable.

How many dB you will get at certain amp power output also depends on the distance and overall room acoustic characteristics (e.g. geometry of the room, size, sound absorbing material etc.). Also, depending on the phone apps you use, you may not be using the same scale that amps/AVR's volume positions referenced to. If you are keen on this, get one of this:

http://www.ebay.com/bhp/radio-shack-sound-level-meter

 

[nunnas]

thank you ill look in to that

 

[lovinthehd]

Your phone app/phone mic at those volumes may not work too well either.

 

[edgebc]

Hey...newbie here. I recently bought a pair of used Maggie 10s for the mains. Very power hungry; so I bought 2 300 amp monoblock no-name amps from Monoprice and an Outlaw processor / amp pair to run the theatre.
My question comes from what I thought must be a typo that states that I am not to use the Monoblocks
on a speaker of less than 8 ohms but it's ok to run the pair of 4 ohm speakers on one amp as stereo.
thus defeating the whole purpose of the second amp.
I know logic is a 50 / 50 proposition in audio math but what is the short explanation of less resistance being too much for the amp to handle?
Thanks.

 

[PENG]

Hey...newbie here. I recently bought a pair of used Maggie 10s for the mains. Very power hungry; so I bought 2 300 amp monoblock no-name amps from Monoprice and an Outlaw processor / amp pair to run the theatre.
My question comes from what I thought must be a typo that states that I am not to use the Monoblocks
on a speaker of less than 8 ohms but it's ok to run the pair of 4 ohm speakers on one amp as stereo.
thus defeating the whole purpose of the second amp.

Are you sure your 300W amps are truely monoblock amps? If they are, then you questions don't make sense. If they are bridgeable two channel stereo amps rated 200W per channel then if you run them in bridge mode, they will work like monoblock amps but then you should use it with speakers rated 8 ohms nominal. If you run them in stereo mode, then you can use them with 4 ohm rated speakers, obviously only one speaker per channel.

I know logic is a 50 / 50 proposition in audio math but what is the short explanation of less resistance being too much for the amp to handle?
Thanks.

Basically if you half the impedance (loudspeaker loads are complex, so avoid using the term resistance), the current will double. If you bridge the amp to function like a monoblock, you basically double the output voltage relative to that in stereo mode. That means the amp will effectively (because of the higher output voltage) see the load impedance halved. Most power amps are not designed for 2 ohm loads. That's why if you bridge a two channel amp for use as a monoblock amp, you should avoid using 4 ohm speakers.

 

[lovinthehd]

Hey...newbie here. I recently bought a pair of used Maggie 10s for the mains. Very power hungry; so I bought 2 300 amp monoblock no-name amps from Monoprice and an Outlaw processor / amp pair to run the theatre.
My question comes from what I thought must be a typo that states that I am not to use the Monoblocks
on a speaker of less than 8 ohms but it's ok to run the pair of 4 ohm speakers on one amp as stereo.
thus defeating the whole purpose of the second amp.
I know logic is a 50 / 50 proposition in audio math but what is the short explanation of less resistance being too much for the amp to handle?
Thanks.

Certainly not a 300 amp monoblock, perhaps you mean one of these 2ch units? Like Peng says about the bridging aspect. https://www.monoprice.com/product?p_id=11497