How much more power would be measurable?

[Shmigsy]

I have a cambridge azur 650R running Energy RC 70 towers and matching LCR centre channel in 5.1. It is a 7 x 100 receiver that is relatively distortion free. Things get a little messy in the final 10db but on a good recording it is still relatively clean.

In Stereo + SW or even pure Stereo (2 channel) I feel there is not enough power. I always want to crank it to 11 if you know what I mean.

How much amplification would i need to make a solid sonic difference?

I play SACD so is a 2 channel an realistic option? Most of my collection is stereo.

The Rotel 1095 seems a decent option at 200 watts per channel x 5 channels.

Thanks in advance for your input.

ps - In my opinion I think a clean 25% more power would be sufficient.

 

[markw]

Well, considering that doubling the power (a 100% increase) to the speakers results in a barely audible 3 decibels of loudness increase, that 25% more power wouldn't amount to a drop in the bucket.

To essentially double the apparent loudness, you need about ten times the power.

That Rotel would be a good place to start.

 

[Shmigsy]

7 x 100 vs. 5 x 200

Thanks for your input.

The 3% increase per doubling is such a weird stat to comprehend; Does that mean that - lets say for argument sake - a Denon Amp rated 7 x 150 is only marginally louder than a Denon rated at 7 x 120 (all other factors being equal)?

So if I drive 200 watts of amplification versus 100 into the RC 70s and only achieve a 3% gain I have effectively wasted my money?

In laymans ears: At the moment When I reach the threshold of my receiver I certainly do not need to double the loudness. That would be crazy loud.

Just don't know where the diminishing returns are in the amp output increase vs. $$$ paid is.

In other words 100 watt to 200 watt is not worth the $$$, better to save up and go X per channel and really feel the difference. Of course the speakers max out at 250 also!

Has anyone been in a situation where they have made the 100 to 200 what jump and can share there experience?

Is there another factor I am overlooking?

The room I am filling is 18 x 33 x 8.

 

[highfigh]

Well, considering that doubling the power (a 100% increase) to the speakers results in a barely audible 3 decibels of loudness increase, that 25% more power wouldn't amount to a drop in the bucket.

To essentially double the apparent loudness, you need about ten times the power.

That Rotel would be a good place to start.

3dB is definitely audible- 1dB is the standard unit of audible change.

 

[JerryLove]

Having said that we are discussing a small change based on WPC: there is more to powering a speaker than simple wattage.

As my experience with some of my recent acquisitions remind me, not all amps are capable of properly driving all loads.

Rather than replace what looks like a very nice AVR (if you do, please feel free to send me your obsolete CA AVR), you might consider just getting a 2-channel amp for the RC70's (say an Emotive XPA-2, which would cost less than the Rotel you are considering and be 300WPC). You'll not only give your RC70's more power, but you'll free up more of the transformer on the AVR for your center and surrounds.

 

[Shmigsy]

3 DB difference

That is what i am thinking also. At present the db level in which the system feels and sounds the best is best described as follows:

I had a AHA moment during a scene in The Last Waltz (lossless blu ray) where they pan a shot from the back of the theatre. At the volume the system was set at it was surrealistic - like being in that seat. Beautiful! Except I would rather have been in the first 20 rows!

So my challenge is figuring out if a 3db change (while maintaining musical fidelity) is going to reproduce that realistic proximity for me.

My gut is telling me 3db might be a little short...

Seems I am discovering how and why Audiophiles are constantly upgrading equipment and changing room dynamics.

 

[Shmigsy]

Having said that we are discussing a small change based on WPC: there is more to powering a speaker than simple wattage.

As my experience with some of my recent acquisitions remind me, not all amps are capable of properly driving all loads.

Rather than replace what looks like a very nice AVR (if you do, please feel free to send me your obsolete CA AVR), you might consider just getting a 2-channel amp for the RC70's (say an Emotive XPA-2, which would cost less than the Rotel you are considering and be 300WPC). You'll not only give your RC70's more power, but you'll free up more of the transformer on the AVR for your center and surrounds.

That is another consideration! I was going to start my investigation on the balance of running the CA on the centre and surrounds and a two channel on the towers. How does something like that balance out for 5.1 movies and SACDs? In those cases would it not be limited to the output from the lesser powered speakers?

Thanks.

 

[JerryLove]

That is another consideration! I was going to start my investigation on the balance of running the CA on the centre and surrounds and a two channel on the towers. How does something like that balance out for 5.1 movies and SACDs? In those cases would it not be limited to the output from the lesser powered speakers?

The matched volume for a given system will be determined by the quietest unit. Before eq, you can determine that from the efficiency of each speaker and with the max power handlin or available amp, whichever is less.

Eq will likely lessen this a couple of db.

I wouldn't worry about the surrounds (2-way speakers with low demands). The only thing left is the center. I suspect hull be fine from an amp standpoint (can't rule out other problems) but if you find that your stereo gets good and movies remain a proble, you can always add a upa-1 for the center or an xpa-3 and still be cheaper than the totem with more power all around.

Put another way: for many an avr is sufficient amp. When it is not, the solution is rarely a more powerful avr... it is instead dedicatdamp (which have the added advantage of not needinggto be discarded when avr tech changes)

 

[zumbo]

Shmigsy,
Keep in mind, that adding an amp to an existing system is not going to change the sound one bit.

Nor is it going to make the system louder at a given level, provided we are talking about the level of the current unit in question at it's current calibration.

What it will do is give the ability to push it to a higher volume while remaining detailed without compression. In other words, it will take more to clip the amp.

IMO, the doubling of power argument is purely SPL. Has nothing to do with compression, clipping, are just the simple description of the sound falling flat because an amp ran out of gas.

 

[90gstman]

I agree with JerryLove, adding a good two channel amp will be the most cost effective way to add additional headroom. The remaining three channels in your 650r should jump up a db or two now that you have effectivly taken 2/5 of the load away from the power supply in the unit.

 

[JerryLove]

Shmigsy,
Keep in mind, that adding an amp to an existing system is not going to change the sound one bit

So you have determined thaat he's not runnimg into clipping, nor amp distortion, and his 3-way passive tower isn't presenting a resistance change that leaves the avr unable to keep his voice coil energized, and that there are no transitory needs that the caps (or power supply) in his avr can't meet? Because any of those would actually effect sound.

How did you make this determination?

 

[zumbo]

So you have determined thaat he's not runnimg into clipping, nor amp distortion, and his 3-way passive tower isn't presenting a resistance change that leaves the avr unable to keep his voice coil energized, and that tree ate no transitory needs that the caps (or peer supply) in his avr can't meet? Because any of those would actually effect sound.

How did you make this determination?

I should add, within the avr's limits.

Which I clearly defined after the above quote.

Shmigsy,

Nor is it going to make the system louder at a given level, provided we are talking about the level of the current unit in question at it's current calibration.

What it will do is give the ability to push it to a higher volume while remaining detailed without compression. In other words, it will take more to clip the amp.

 

[zumbo]

How much more power would be measurable?.
How much amplification would i need to make a solid sonic difference?

Looking back at the initial question, it is a double edged question.

Measurable is one thing.

Sonic is another.

Fuzzy feeling of the separate amp with slightly more power actually making a difference in either is yet another.

But adding a 300W beast. No we're talking difference. Yet here, if the volume is within the current avr's limit, it's gonna sound the same.

 

[zhimbo]

In Stereo + SW or even pure Stereo (2 channel) I feel there is not enough power. I always want to crank it to 11 if you know what I mean.

I don't have any particular advice, but...is it possible that your subwoofer is what is lacking? Those Energy speakers seem pretty sensitive and I would expect them to play pretty loud with a decent AVR, so I'm wondering if the bass frequencies are getting swallowed up in a large open room, and that's the "oomph" you're missing.

 

[zumbo]

I don't have any particular advice, but...is it possible that your subwoofer is what is lacking? Those Energy speakers seem pretty sensitive and I would expect them to play pretty loud with a decent AVR, so I'm wondering if the bass frequencies are getting swallowed up in a large open room, and that's the "oomph" you're missing.

Very good point. Which is something I am trying to convey in another thread. No matter what specs say, 6.5" woofers are just not going to give the feeling of power, no matter how much power you send to them.

A premium quality sub will make more of a difference in any system. Most of us just get side-tracked on the initial point of the question in the thread.

 

[JerryLove]

But adding a 300W beast. No we're talking difference. Yet here, if the volume is within the current avr's limit, it's gonna sound the same.

That illustrates my point. You post as though wattage and volume are the only two variables. They are not. My avr would not drove my 801's at even her moderate volumes without severe midrange harshness. I put a more capable amp in and that went away (though I am still having issues with the bass driver).

Now I do agree that we have not determined what the actual caused of his experience is. It could be setting, or speaker, or sub, or amp.

*if* there are no all deficiencies in his current setup then you are absolutely correct ; the only difference will be 3db per doubling of wattage until he maxes re speaker. Whether the current amp is sufficient is unknown.

If the quesion is simply "what is the best way to add more power" then I stand by my suggeston. It is the most power for the least money.

 

[zumbo]

You just had to throw the 801's in here didn't you.

Like bringing a Corvette to a Chevette race.

I am trying to base my replies on the equipment at hand.

Pretty sure the RC70's are able to perform well within the avr's limit.

 

[JerryLove]

Fair enough. If you have experience with these speakers; I don't.

 

[zumbo]

Fair enough. If you have experience with these speakers; I don't.

Very similar in build and design to mine, with an added 5.5" mid. However, the RC70's are an easier load.

RC70's: 8ohm 92dB

Mine: 4ohm 87dB

EDIT: Guess they are not that similar. LOL!

 

[walter duque]

To anwser half your question, if you add something similar to this (350x6--300x2)

which is my little antique stack (in a small apartment) you can go to +5db. You will hear and feel the difference, guaranteed.