SDA power consumption

[TroyD]

You know, several people have commented about how much power the SDA's consume. I'm not picking on anyone in particular but I just don't buy it.

I don't recall the specs right off hand, but if memory serves, they are all around 90db 1w/m efficient.

As a VERY unscientific test, I tossed in Telarc 'Round Up' and cranked up William Tell Overature as loud as I could stand and positioned myself to where I could keep an eye on the V/U meters on my TFM-45. Now I KNOW that the V/U's aren't all that accurate but there wasn't a peak EVER over 40 wpc. Even if you double it, you still aren't close to 100 wpc. Continuous, never broke 10wpc.

Again, I realize this is LESS than scientific but it's still enough for me to question just how much power SDA's require.

BDT

[jdhdiggs]

Yup, did the same with my system. Highest peak was 60W and highest sustained was about 15W and it was deafening.

At TPG2, Tour got Russ's SDA/carver rig to peg out around 200W IIRC on Trycicle. I think Russ filled his pants on that one. And yes, it was earbleed loud on the attack.

[dorokusai]

I think that quality power is far more important than quantity. I agree. I tried to cover both bases so I don't worry about that anymore.

James - LOL, I remember that.

[reeltrouble1]

When I brought my SRS home that was exactly what I thought, hey 90 db. efficient, my amp is putting out 375 wpc at 4 ohms with 75 amps peak2peak and that will be more than enough.

My experience though has been that although it seems to be plenty of power for the tweets and mids the low end would like some more. Big watts on a passive radiator. When I kick the subs on with the SRS I am definetly going lower, so the musical information is there.

I can say that when I pumped around 600 wpc into the 1C the bottom end "woke" up and I was digging deeper. Now they are different speakers, different rigs and the rooms are much different. But the 1C's are able to go lower right now.

I suspect the room size where I have the SRS is a big part of the difference as it has over 3500 cu ft. and some large openings, whereas the cave is a closed room and around 1350 cu. ft.

Dont read me wrong the SRS sound wonderful and are the overall better speaker, I am not talking about how "loud" but how deep I can get at a reasonable listening level. They will play plenty loud, ear deafening loud actually. I just think they would like some more power for the bottom end, if someone has a better idea, fire away.

[jdhdiggs]

Also, most amps topographies mean that not all watts are created equally so only using 10% of the rated power will generally mean better quality watts than using 90% of the power. (This is for SS, I'm not opening the SET, push-pull, tube whatever debate although I think it holds.)

Mark: I think the term was "'effin stupid loud" only without the censorship... BTW, Have you warned your neighbors for this spring?

[hotwheelman]

Current flow man, current flow..thats all I got to say about that.:D

[organ]

Originally posted by hotwheelman
Current flow man, current flow..thats all I got to say about that.:D

LOL That's what I was thinking. I think a good amp should be able to deliver a good constant current flow and have the reserves when called upon.

Troy said his SDA's are 90db/w/m. 90db at 1m is pretty damn loud. It should be louder in a home if Polk measured the sensitivity in an anechoic room.

Maurice

[Frank Z]

Well my wife's little under-powered 2 channel rig is pretty damn loud.:D

[Dennis Gardner]

Requiring and consuming seem so mechanical, Troy.

"Loving and responding" to high current are better choices of words on Valentine's Day.:D :D :D

[michael_w]

I've heard of a formula... sensitivity = 90 db @ 1m/1W to get a 3 db gain you have to double the power (now 2W), then double it again to get another 3 dbs.... Is this formula correct to a certain extent?

[Dennis Gardner]

90db=1w
93db=2w
96db=4w
99db=8w and just for kicks:

102db=16w
105db=32w
108db=64w
111db=128w
114db=256w
117db=512w
120db=1028w

This is where the sensitivity argument for easy to drive speakers like Klipsch comes into play. Some of them start out around 96-99db efficiency.

[madmax]

Originally posted by Dennis Gardner
90db=1w
93db=2w
96db=4w
99db=8w and just for kicks:

102db=16w
105db=32w
108db=64w
111db=128w
114db=256w
117db=512w
120db=1028w



So that is why my neighbors moved far far away...

[Tour2ma]

Originally posted by jdhdiggs
At TPG2, Tour got Russ's SDA/carver rig to peg out around 200W IIRC on Trycicle. I think Russ filled his pants on that one. And yes, it was earbleed loud on the attack. "Attack" being the key word here... very dynamic recording and dynamic is safer all around for speakers and electronics.

Also in play was the size of Russ' cave, i.e., relatively small. As Ted was musing above, room size has a great deal to do with the power requirements, if for no other reason than that you can't get too far away.

And that TFM is good to ~300 wpc continuous into a 6-ohm load...

[organ]

Originally posted by madmax
So that is why my neighbors moved far far away...

LOL How many wpc you got goin there, Madmax?

Maurice