Power Needs for SDA-2

read-alot

heiney9 wrote:

Read-alot, your splitting hairs and really the impedence shouldn't be an issue at all if you are using even a modestly competent amp or receiver. Certainly more power in almost any situation is better; is it necessary to power the later generation SDA's..........n

H9

heiney read the title to this thread - he is not powering the later generation he has the same speakers I have powered for the last 21 years. SDA-2s will clip and smoke amps speaking from sperence.

heiney9

Got it, thanks for pointing that out. I thought the concern was about 2.3tl's, my bad.

H9

heiney9

Interesting tidbit that relates to this discussion

FWIW,

Load
In electrical terms a load is something that dissipates power and does some work. The work done may take many forms, including generating heat as almost always happens as a side effect of work being done. Without a load no power can be transferred. A speaker is the load for a power amp. In order for current flow to occur a complete circuit must exist. In order for the circuit not to be a short-circuit (a decidedly bad thing) a load must be present to the power the amp. The power amp drives power through the circuit by way of increasing the voltage at its outputs and as a result the load (speaker) draws current and does work. In this case two major forms of work occur: The speaker moves and generates sound, and heat is produced. Any device you plug into an electrical outlet can be considered a load (toaster, light bulb, etc). Plug in too many devices drawing too much current and you will "load down" the power delivery system (another bad thing). In order to protect against this power delivery systems have fuses and circuit breakers to break the circuit when current flow gets too high. Many power amps employ current limiting devices in their output stages to limit current flow without interrupting the audio. It's sort of a self regulating protection system (back in the old days the amp just blew up). An important thing to understand is that a load will DRAW from an available pool of power all of the current it needs to operate at the given voltage. This is somewhat simplified, but in principle remains fundamentally true for all electrical systems. A speaker's impedance rating is an indication of what kind of load it presents to an amplifier. An appliance's current or amperage rating is exactly the load it will place on the electrical system. The reason a speaker cannot be rated in exact terms of current usage is because the voltage and frequencies presented to it constantly change. Impedance is a way of approximating a speaker's resistance to a varying voltage and frequency signal.

Also related to us is acoustical loading. The efficiency of a loudspeaker depends to some extent on the acoustic load placed on it by the way it couples to a cabinet and the surrounding structures. A speaker placed in the throat of a horn, for example, will see a higher acoustic impedance than a speaker placed in a free space.

TroyD

.......nevermind, already been said.

Press on!

BDT

wire

Paraclete wrote:

I have a pair of SDA-2, and have been using a Sony STR-DB930 receiver to power them (110W/Channel). I use them as the front two speakers in a 5.1 surround system, and at higher volume levels coupled with dynamic audio parts of movies (explosions etc) I hear some popping and clipping. I suspect that it is a lack of power, but 110w does not seem like a small amount. What is the needed power for optimal sound from these wonderful speakers?

Yeh
You need more good power ( high Current ) , the more the better . Dont go with a all in one unit . Try Amp , Preamp with them .
I power mine 2b's ( are 6 ohms ) with a Bryston 4b ( ever since i bought them new ) . The Bryston gives them a great sound with a great sound stage .
Look around and try out what kind of sound you like in a Amp . Each brand has there own sound . I like Bryston sound and there built to last most of your life .

markeddie

A different train of thought; a new question, does the protecion circuit on the SDA 2s, specifically the 2Bs get weak over time? It seems it had gotten easier to trip them, and I know I need to get better power.

heiney9

markeddie wrote:

A different train of thought; a new question, does the protecion circuit on the SDA 2s, specifically the 2Bs get weak over time? It seems it had gotten easier to trip them, and I know I need to get better power.

Yes, the polyswitchs get old over time. Call Polk CS and they will send you new ones free of charge. You'll have to pull the x-overs yourself, but it's a straight forward solder. Have a buddy there for a 2nd pair of hands it goes quicker that way.

H9

Paraclete

I am upgrading my system, and after talking with you folks, have decided to go with some separates: Looking at Anthem AVM30 pre-amp, and Anthem MCA50 Amp., plus a Richard Gray power conditioner, as well as a Sonamp 3 zone amp for the ancillary speakers around the house.

I cannot find the nominal rating for my Polks SDA-2. The Anthem amp is rated at 225 Watts/Ch.

Any thoughts on (1) nominal rating for these fine speakers, and/or (2) my tentative choice of upgrades?

dorokusai

The SDA's are around 500wpc, so you'll have no problems. Even if it was lower it wouldn't matter.