Power amplifiers and lower listening levels

tonyb

joecoulson wrote: »

So if an amp says input power is 400 watts max and it’s a 125wpc amp, that’s good right?
Or just about avg? Or I don’t know what I’m talking about?

Joe, forget you ever heard "input power", means didly. F1NUT has it spot on.

tonyb

Clipdat wrote: »

mhardy6647 wrote: »

This is my rambling way of saying that the trick is to find an amplifier that sounds really good at really low output levels.

How can one find an amplifier that excels at this? What specific traits about the amplifier should one be looking for?

It's a complicated answer to a simplistic question. You really don't go looking for an amp that does well at lower volumes, you look to put together a recipe that will achieve it.

Personal observations, so take no offense. The Polks simply won't do all that well at lower volumes. Get an easier to drive speaker, more efficient, less drivers. Tekton speakers would be a good example.

Find an amp with a good amount of current, a more even power bandwidth. Some can have a top heavy bandwidth meaning you'd have to crank it up some. Also make sure the incoming impedance is a good match for the pre amp's outgoing. That alone can make all the difference in the world.

Lastly, and again...no offense, but the King Cobra IC's in my opinion would be better swapped for something from Wireworld eclipse series or Acoustic zen Matrix 2's. OCC copper will give you better clarity at lower volumes.

Just my .02....a different amp alone isn't going to solve your problem .

Clipdat

tonyb wrote: »

Lastly, and again...no offense, but the King Cobra IC's in my opinion would be better swapped for something from Wireworld eclipse series or Acoustic zen Matrix 2's. OCC copper will give you better clarity at lower volumes.

I was under the impression that Audioquest's "PSC+ Copper" was functionally equivalent to OCC copper.

tonyb wrote: »

Just my .02....a different amp alone isn't going to solve your problem.

Just for the sake of clarity, I never mentioned that I have a "problem", I simply made this thread as a learning opportunity.

joecoulson

Forgetting input power.

I know my 705’s seem to just start to open up around 75db.

The totems are not super efficient but they do much better at lower level listening. But it might be the aluminum tweeter vs ring radiator

tonyb

joecoulson wrote: »

Forgetting input power.

I know my 705’s seem to just start to open up around 75db.

The totems are not super efficient but they do much better at lower level listening. But it might be the aluminum tweeter vs ring radiator

Input power as it relates to being stamped on the back of an amp Joe. With amps, it's output power to concern yourself with, not input.

How's those Totems with dynamics though at lower volumes ? Clarity and dynamics is 2 different cats to skin at lower volumes.

mhardy6647

The issue of what flavor of power is needed to drive a loudspeaker does depend on the nature of the loudspeaker. Loudspeaker impedance is a function of the electromechanical parameters of the individual drivers, the design of the crossover network, and the alignment of the box into which it is all put!

My point is that the operative parameter was, is and shall always be power (which is why the gizmo used to drive a loudspeaker is called a power amplifier) ===

but, but, but...

What it takes to deliver that power into the load depends absolutely on the nature of that load.

The fashion today is for loudspeakers with a low nominal impedance and complex frequency-dependent impedance, coupled with low sensitivity (SPL "out" per watt "in") and low electrical efficiency (acoustic watts of power "out" per watt of electrical power "in"). Modern loudspeakers tend to be what an EE would call a "highly reactive" load -- they don't behave like a resistor, with a fixed impedance that is independent of frequency, but rather they act like a complicated network of resistance, capacitance and inductance (and the latter two vary depending on the frequency).

Such loads do in fact put great demands on the ability of an amplifier to deliver the power necessary for the loudspeaker to do its job (which is to transduce an electrical signal into an acoustic pressure wave) -- and, yes, in many cases, this does require large amounts of current.

But, Ohm's Law prevails, and the amp must deliver the necessary voltage and current into the load, from instant to instant, across three orders of magnitude of AC frequencies (ca. 20 Hz to 20,000 Hz) for us to say "hey, that sounds pretty good".

Which is nothing short of amazing now -- and even more so when one has a chance to listen to state of the art hifi reproduction equipment from the 1930s or 40s.

joecoulson

tonyb wrote: »

joecoulson wrote: »

Forgetting input power.

I know my 705’s seem to just start to open up around 75db.

The totems are not super efficient but they do much better at lower level listening. But it might be the aluminum tweeter vs ring radiator

Input power as it relates to being stamped on the back of an amp Joe. With amps, it's output power to concern yourself with, not input.

How's those Totems with dynamics though at lower volumes ? Clarity and dynamics is 2 different cats to skin at lower volumes.

I used to have the totems hooked up to a Jolida integrated back at my previous house and they played low in the background while working. They exuded all frequencies very well at low levels.
The polks are not that way, they need much more power to open up. But the polks are easier to listen to with my current setup. The totems are a little bright at higher volumes.

motorstereo

My 2 cents worth. I also agree that my sda's don't open up really well at very low volumes either. It does take a few extra clicks of the volume knob to get the best from all those drivers imo.
I also have a pair of khorns that are well known for being dynamic and yes they will open up with at very low volumes with low powered quality amps. The problem though with the khorns is listener fatigue sets in quickly. They are not all day listeners like my Polks are at the same low volume. So even though the dynamics aren't there the overall smoothness make the Polks (to my ears) the preferred low volume speaker to listen to all day.

delkal

motorstereo wrote: »

My 2 cents worth. I also agree that my sda's don't open up really well at very low volumes either. It does take a few extra clicks of the volume knob to get the best from all those drivers imo.

This is probably unrelated but I always wondered about Polk amplifier ratings with the SDA's. The TLs recommend a 50-1000watt amp. But they are 92 db speakers so for normal listening levels you are only using around a watt.


I understand SDAs can be power Hungry and you cant run them with a flea amp. But is this Polk's subtle way to say these speakers sound best cranked up??

F1nut

For the record, the 2.3TL and 3.1TL are 90dB while the 1.2TL is 91dB efficient.

tonyb

delkal wrote: »

motorstereo wrote: »

My 2 cents worth. I also agree that my sda's don't open up really well at very low volumes either. It does take a few extra clicks of the volume knob to get the best from all those drivers imo.

This is probably unrelated but I always wondered about Polk amplifier ratings with the SDA's. The TLs recommend a 50-1000watt amp. But they are 92 db speakers so for normal listening levels you are only using around a watt.


I understand SDAs can be power Hungry and you cant run them with a flea amp. But is this Polk's subtle way to say these speakers sound best cranked up??

Those recommended watts numbers are usually worthless. The reason why you have to crank them up a bit is because of the multiple drivers SDA's have. Takes current to move them, to start and stop them. Amps won't deliver their rated current at low volumes.

mpitogo

@Clipdat I favor a clean powerful amp for low volume listening. Like you I also typically listen at lower volumes but occasionally crank it up.

cfrizz wrote: »

I purchased a 205wpc Parasound 1500A amp, and it was an ear opening experience. My easy to drive Polk RTA-8Ts woke right up.

My journey had ended with an MC452 for my LSiM707. I also heard a similar eureka moment like yours the first time I put the 450wpc amp on them.