Polk SDA SRS power recommendation (RMS)

[deep bass]

I have been searching, and i am unable to come up with an answer to my question. "What is the recommended or RMS of the Polk Sda Srs's?" According to the Polk Audio website the power recommendation is 1000watts...

The Polks are 1000 watts? 1000 watts what? Program? Peak? RMS?
amplifier power. What kind of top end does that give us? 250 watts? 500 watts? VERY little information here unfortunately.

Does anyone have any ideas or throughts? Please feel free to comment or leave feedback. All the help is appreciated.

Thank you,
-Deepbass

[BigMac]

Hi. I am new here but thought I would try and help out best I can. Here are the specs for the SRS 2. I could not find the SRS info, sorry.

SDA SRS 2 (1986-1988) - VARIOUS - WALNUT

Driver Compliment:
Two 1 Inch SL2000 Silver Coil Dome Tweeter
Four 6 1/2 Inch MW6509 (6510/6511 '87-'88) Tri-Laminate Polymer Bass-Midrange Drivers
One 15 Inch SW150 Fluid Coupled Passive Radiator (SW155 '87-'88)

SDA Interconnect: Blade/Blade (Pin/Blade '87-'88)

Size(Inches): 50H x 20 11/16W x 12 11/32D

Shipping Weight(Each): 142 Lbs

Frequency Response: 12Hz - 26kHz

Frequency Response(-3dB): UNK

Recommended Amplification: 10 - 750 watts/channel

Nominal Impendence: 4 Ohms 1986-1987 (6 Ohm '87-'88)

Efficiency: 92 dB


Also, here is a link that may be of some help as well. The guys/gals here are very good with this info.....they know it like the back of their hand. Tomorrow I am sure you will get a bunch of responses better than mine,lol.

http://www.polksda.com/

Link to the .pdf for the SRS 1: http://www.polksda.com/pdfs/SDA1.pdf

[george daniel]

This may not be an answer to your question,, but it has been my experience that you should feed them with as much high current/power that one can reasonably,(or unreasonably) afford.Good luck. :)

[ben62670]

They are very efficient speakers, but have many drivers. You need high current. I would recommend looking for at least a GFA-555. This gives 325wpc clean with lots of current. Many know I am partial to Adcom's here, but they can really provide the juice needed.
Ben

[george daniel]

or 2,,, adcoms that is,, bi-amp the lows,,,bi-ampthe mid/highs,,,ooops,, Lunesta's kickin' in,,off to the good ship lollypop ina fes minutes---george----out,:D

[PolkClyde]

They are very efficient speakers, but have many drivers. You need high current. I would recommend looking for at least a GFA-555. This gives 325wpc clean with lots of current. Many know I am partial to Adcom's here, but they can really provide the juice needed.
Ben

In Stereophile magazine wasn't The Adcom GFA-555 Rated as a Class D Amp? I have the Adcom Pre-amp 565 I believe it is. I don't pay too much attention to most of the rating I just let my ears do the judging.

[ben62670]

The 555 is a very close design to the 565, and 585 with the gain stages being different. All three used big fat caps, large toroids, and the same out put devices. The 565, and 585 used different style gain stages. A 555 can be had for $300 plus shipping while 565's get at least $900 a pair if the input boards have been replaced.

[SDA SRS 1.2]

According to my original SDA booklet that came with the 1.2's it says "Rec. Amplification: 50-1000 wpc"

[zingo]

I believe what Polk is saying with the 1000w recommendation is the more the better. A 200wpc amp would be fine, Ben's 555s would be even better, and a 1000wpc would also work if you could find it/afford it. Like Ben says, feed them as much clean, high current power as you can afford.

[george daniel]

The 555 is a very close design to the 565, and 585 with the gain stages being different. All three used big fat caps, large toroids, and the same out put devices. The 565, and 585 used different style gain stages. A 555 can be had for $300 plus shipping while 565's get at least $900 a pair if the input boards have been replaced.

Gawd,,, I just love big fat caps :p:D

[deep bass]

I believe what Polk is saying with the 1000w recommendation is the more the better.

Thanks for the responses... (i still wish there was a more concrete answer to the power handling situation... rms)

Theoretically lets say i power them up with 400-600 watts per channel... would this be ok?

Another question i just thought of... "What gauge speaker cable should i be using? 10-12 gauge with the 400-600 watt configuration?

[BIZILL]

in short. give them 400wpc and use 12 gauge speaker wire. period. move along people. nothing to see here.

[Joe08867]

I think you are on the right track. 400-600 is a great area to work in for powering your towers. I am a proponent of good clean hi current power. And with your speakers as much as you can find up to 1000 watts.

As far as cables go I am a 10 gauge guy usually. But cables are always a debate around here.

[BIZILL]

I think you are on the right track. 400-600 is a great area to work in for powering your towers. I am a proponent of good clean hi current power. And with your speakers as much as you can find up to 1000 watts.

As far as cables go I am a 10 gauge guy usually. But cables are always a debate around here.

BIGGER is always better. i'm just not trying to confuse the lad and trying to keep it simple. he seems to be looking for ONE answer. now he's armed with it.

[gdb]

DeepBass, I am going to go pick up SRS2s tomorrow. I've always been advised that Too Little Power is what will kill a speaker! (clipping) I've also been told that amps that are bridged to produce mono output, don't like driving 4ohm loads. I've also learned that whatever is used to drive SDA models HAS to have a "common ground" or a very specific IC cable must be used between the speakers to prevent damage/destruction ! I'm going to start off with a Carver that's rated 400wpc into a 4ohm load and see how it goes,if it's true that the SRS2 can be bi-amped, I'll research that possibility and maybe give it a try. If you start with a lower powered amp, I'd just advise to go easy on the volume control and back it off if straining or distortion is heard. Good luck !!:)
Oh yeah, I forgot to mention that the high watt rating for an amp usually refers to reserve/head-room/peaks in the music. Continuous listening at maximum output, you'd go deaf real soon!!

[heiney9]

Read this review it might shed some light. You are over thinking the issue. A high quality, high current amp in the range of 100-1000 wpc will work out just fine unless you have an unusual circumstance. Such as a huge room, the size of auditorium, or if you want to go deaf.

Pay little attention to wpc and more attention to the quality of those watts, current, etc and you'll be fine.

The very first question you have to ask yourself is: What am I trying to accomplish? We know nothing about the rest of your system or how you intend to use it or what you'll be playing through it or how you want it to sound or the size of your room, etc.

There is no "one" amp/watts/current/type that fits every situation despite what some might convince you here. There are good rules of thumb to follow but you need to figure what you want out of your system and how your going to use it and what your end expectation is.

Read the article it gives good insight as to what the SRS system is capable of.

http://www.polksda.com/srsreview.shtml

H9

[Joe08867]

BIGGER is always better. i'm just not trying to confuse the lad and trying to keep it simple. he seems to be looking for ONE answer. now he's armed with it.

No problem BIZILL. I was actually typing my answer when you posted yours. I agree keep it simple is probably a good idea. Especially when new to all of this stuff.

[gdb]

You'd have a hard time finding someone newer than me to this stuff! Thanks Heiney9 & BigMac for the links, they were put in my favorites immediately!:D

[zingo]

Just get a pair of Mcintosh MC1201 and put to rest your amplification worries.

[ben62670]

Straight from Ken at Polk. It was a while ago when I asked pertaining to my SDA project.
"50-60 watts per woofer" would put them at near max. This is clean power from an amp. So if you have 8 woofers per speaker(1.2s) you can use 400wpc. Going over lessens the load on the amp if you like to run them full out for long periods.
Ben

Edit. BiAmping the tweeters helps protect the tweeters from clipping;)

[eeagle]

I think the real question here was is the power rating RMS, peak or some other variety?

Non of the Polk documentation I have actually states what the 1000 Watt Max Power rating is.

Can we safely assume that back in the real Hi-Fi days of the SDA line that RMS (ie the "REAL" power rating) is implied?

[ben62670]

In the 80's there were a lot of bloated RMS rating. Come to think of it it is still that way. If you want to shop by RMS you are doing yourself a great disservice, and your speakers. As you noted it does just say maximum power. This could translate inti dynamic, or transient peaks;)
Ben

[eeagle]

In the 80's there were a lot of bloated RMS rating. Come to think of it it is still that way. If you want to shop by RMS you are doing yourself a great disservice, and your speakers. As you noted it does just say maximum power. This could translate inti dynamic, or transient peaks;)
Ben

Interesting thought...there is certainly a lot more definition needed....especially in the distorion area.

So has anyone actually pushed a set of big SDAs with a clean 1000W RMS :) ...is it a good spec or do they fall apart? WOW I can see all the variable in this equation spinning in my head.

Can't even imagine...my 300W setup is more than DW can stand, even when I'm at quarter volume...I don't have the test gear to know what my max, avg, peak or whatever RMS power is.

[ben62670]

1000 watts of clean high current power will melt them!
I put a about 1100wpc to these, and they were maxed out.
http://www.polkaudio.com/forums/showthread.php?t=53273

[heiney9]

Interesting thought...there is certainly a lot more definition needed....especially in the distorion area.

So has anyone actually pushed a set of big SDAs with a clean 1000W RMS :) ...is it a good spec or do they fall apart? WOW I can see all the variable in this equation spinning in my head.

Can't even imagine...my 300W setup is more than DW can stand, even when I'm at quarter volume...I don't have the test gear to know what my max, avg, peak or whatever RMS power is.

If you read the article I linked to in an earlier post you'd see what they maxed out at in the lab.

H9

[Polksaladanni]

GFA555II

The Beast from the East.

[leroyjr1]

GFA555II

The Beast from the East.

GFA-555II x 2 = :D

[ben62670]

GFA-555II x 2 = :D

They will surely die. Do not bridge amp, and tie them together. A fellow Polkie did this, and it was not nice. It was expensive/explosive! You can run one for the highs, and one for the lows;)
Ben

[george daniel]

Again :) High Current---look at parasound, belles,Bat, to name a few,with that said,, it's up to a person and their wallet,,have fun :)

[eeagle]

If you read the article I linked to in an earlier post you'd see what they maxed out at in the lab.

H9

Thanks! I missed that link. Great review, with many questions answered. I made a .pdf for my file.