Salk Speaker Power Handling

newzooreview · « **on:** 18 Oct 2009, 10:15 pm »

I'm trying to de-ignorant myself about power handling.

I've never worried much about it since in the past my systems haven't sounded really good at high volumes, so there was a natural limit to how far I cared to push things. However, having heard the Salks at Dennis's last week, it's clear that they play beautiful music at high volumes. Coupled with the fact that I now have a 500 watt/channel amp

, I think I better educate myself.

Question 1: When the Salk website says that a speaker can handle up to 250 Watts of solid state amplification, should I read that to refer to continuous power or transients?

Question 2: If that is the maximum that a speaker can handle (e.g it means transients), is there a good rule of thumb I could follow to make sure my amp doesn't do any harm? For example, the amp volume is adjusted as % of maximum, so would it be safe to keep the amp at 50 (e.g. 50% of 500W) to limit the output to 250W max.? Or is that not how amps work--will the amp draw more than 50% of maximum to feed transients?

Question 3: What determines power handling? I assume that it's really more than one number: there's the power handling of the woofer (250W on the Seas W18) and for the tweeter (150W, I think, for the LCY 110). So, depending on the frequency the power handling may be lower?

Question 4: What is the actual power handling on the HT1-TL? It hasn't made it onto the Salk site yet, and I seem to have missed the info on the forum.

I think that covers most of my confusions!

grantc79 · « **Reply #1 on:** 19 Oct 2009, 12:26 am »

Honestly,

I think you'd have a very very hard time blowing a speaker due to too much power. In order to do that you'd have to force feed a lot of juice (I mean a whole lot) into a speaker that isn't rated for anywhere near that much at insane volumes over a long period of time.

Where you normally harm speakers is when you try to play them at loud levels without enough power.

That is really when speakers get damaged.

With 500 watts your perfectly fine to do whatever you want as loud or soft as you want.

srb · « **Reply #2 on:** 19 Oct 2009, 12:48 am »

Quote from: grantc79 on 19 Oct 2009, 12:26 am

I think you'd have a very very hard time blowing a speaker due to too much power. In order to do that you'd have to force feed a lot of juice (I mean a whole lot) into a speaker that isn't rated for anywhere near that much at insane volumes over a long period of time.

It is true that most speakers are damaged from not enough power when they get turned up to the point that the amplifier is clipping.

But given enough amplifier power and headroom, it also depends on the room. What may be an "insane volume" in a small to medium room, may not be all that loud in a very large room at a good distance from the speakers. In that case, some speakers may run out of power handling capability trying to fill a large room with sound in a far field setting.

Steve

newzooreview · « **Reply #3 on:** 19 Oct 2009, 12:58 am »

Thanks, grantc79. I've also heard that it's a lack of clean power from the amp that is the culprit in blowing a speaker rather than absolute power. So, a 50W amp turned up too high could blow the speakers while a 500W, playing the speakers at louder volumes could be fine.

So, in that case, what is the "power handling" information on a loudspeaker meant to convey? If it's not about maximum safe wattage to the speaker, then what's it about?

Is it an indication of "maximum usable wattage"? Meaning SPL (dB) doesn't increase beyond that wattage? In that case it would be better to simply state the maximum SPL that the speaker can produce.

Still confused!

newzooreview · « **Reply #4 on:** 19 Oct 2009, 01:01 am »

Steve, are you confirming what I just wrote: "power handling" = "maximum SPL (dB) that the speaker can produce"?

In that case you should be able to take the efficiency of the speaker, factor in the power handling, and come up with a figure for max. dB at 1 meter (at a specific frequency). Is there such a calculation that can be made?

DMurphy · « **Reply #5 on:** 19 Oct 2009, 01:39 am »

Quote from: newzooreview on 19 Oct 2009, 01:01 am

Steve, are you confirming what I just wrote: "power handling" = "maximum SPL (dB) that the speaker can produce"?

In that case you should be able to take the efficiency of the speaker, factor in the power handling, and come up with a figure for max. dB at 1 meter (at a specific frequency). Is there such a calculation that can be made?

But it all depends on what kind of signal you're feeding the speakers. And that isn't standardized in any of the power handling specs. If you use a true continuous sine wave signal at a very high level over an appreciable period of time (10 seconds or more), you're probably going to start smelling resistors in the crossover before anything desctructive happens to your speakers, assuming the crossover isn't asking the tweeter or mid to operate below its frequency response design limits. If you're talking about a music signal, there's too much variation in the content to conclude much about power handling. Unless you want the FTC to step in and standardize everything (be careful what you wish for), you're just going to have to take the power handling specs with a salt shaker in hand.

jwes · « **Reply #6 on:** 19 Oct 2009, 02:14 am »

This is a great thread, because understanding power handling is so important. I've also been confused. My current amps, Spectron Musician III Mk2 in Monoblock are supposed to have ridiculous power: 7,000 Watts peak for 500 ms. Nominal is way above above any speaker ratings. And yet, they don't kill my current speakers - Dali Euphonia MS4's. I have my tubed pre-amp set for unity gain.

I think the Salk would handle high "quality" power just fine. But it's great to figure this out if there's a definitive source to understand this.

By the way, thanks very much to Joe (jbtrio) for great advice and help and to evan1 for suggesting to reach out to him. Now to start the process of putting the $$ aside!!!

Jim

newzooreview · « **Reply #7 on:** 19 Oct 2009, 02:51 am »

Thanks, Dennis. I kind of figured I shouldn't worry about it, but my technical curiosity wanted some sort of insight.

I'm still wondering how power handling relates to maximum SPL. I found an SPL calcumalator, but it doesn't seem to care about power handling, just sensitivity. It's interesting, however (to me, at least).

http://myhometheater.homestead.com/splcalculator.html

newzooreview · « **Reply #8 on:** 19 Oct 2009, 03:16 am »

Jim, I think there's some good info here, but it turns out to be a rather complex topic (as Dennis alludes to)--> http://sound.westhost.com/articles/pwr-vs-eff.htm

I came to the conclusion that the HT1-TL's that I have on order should reach a 105-110 dB concert volume at my listening position with my 500W amp while retaining some headroom for dynamics (Wyred4Sound STI-1000). And I also concluded that I'm unlikely to burn out the Salks at those volumes with good power.

But I guess it would be good to know what the limits might be on that. Can I play a rock concert at near those SPLs for an hour without risking a crossover burnout as Dennis describes? He seems to suggest it would take a sine wave at some unlikely high level to really do that (smoking crossover parts, I mean). I fully trust that, but how close am I coming to that condition with real music at concert volumes?

I fear that Dennis is right that the answer is "depends".

newzooreview · « **Reply #9 on:** 19 Oct 2009, 03:42 am »

Here's another link discussing the relationship between speaker sensitivity, amplifier power, and concert volume (but not "power handling"):

http://74.125.113.132/search?q=cache:FIT-hTpTBGkJ:www.musicalfidelity.com/products/supercharger/advert_response.html+symphony+concert+spl&cd=7&hl=en&ct=clnk&gl=us&client=firefox-a

Nuance · « **Reply #10 on:** 19 Oct 2009, 06:31 am »

So, in theory, you could hit 105-110dB before the woofers bottomed out, or before the amps clipped?

Wayner · « **Reply #11 on:** 19 Oct 2009, 11:50 am »

First, let's back up a little. It depends on the amp and it's ability to handle loads at high power. Not all of the Salk speakers are at 8 ohms, and no speaker made by anyone are at just "8 ohms". The fact is their impedance goes all over the place, usually rising at the resonance frequency but varying across the frequency spectrum. Some amps can handle low impedance outputs while others not so well. The earlier case type amplifier will clip, sending DC voltage to the drivers, causing the voice coils and cross-over elements to start to heat up. A DC signal is zero movement for the speaker so even for micro-seconds, this energy gets turned to heat. A continuous bombardment of this type of signal will bring destruction.

There is always the power squared principal. If you are playing music at one watt, it will take 10 watts to make it twice as loud, 100 watts to make that twice as loud, 1000 watts to make that twice as loud. So as you can see, there really is a limit even to amplifier size and this is some of the reason. Larger amplifiers have a bit more headroom to handle the momentary peaks at elevated levels. You may be lucky enough to own an amplifier that can play at those sustained levels, but I suggest using prudence concerning the volume control. I find where the speaker starts to even slightly strain and then back the volume off a bit. That is your maximum volume level. Also, at such high listening levels, your ears are going to suffer. I really never turn the volume control much more then 11 O'clock and then it depends on the music content and which pair of speakers I have hooked up to which amp.

Wayner

newzooreview · « **Reply #12 on:** 19 Oct 2009, 12:52 pm »

Wayner, many thanks. I know a lot of amps don't like the lower impedences that a speaker can present at certain frequencies. I always check that an amp can truly double power output into 4 Ohms: the Wyred4Sound amps do, as I'm sure the AVA amps and other well-designed amps do as well. My main interest in that regard is handling transients well vs. actually blasting the music for long periods at really high volumes. 90% of the time I wouldn't want to do that (and maybe 40% of the time I listen at background levels).

I'm more curious about the theoretical limits. The Salk speakers play so cleanly that I might push them to higher SPL than I am used to with other speakers (Dennis and I got to some reasonably loud volumes with a Janacek piece that sounded terrific and dynamic). So, I started wondering about the technical limits. I will be prudent, as you suggest, but I'm also inquisitive.

mathgeek97 · « **Reply #13 on:** 19 Oct 2009, 01:06 pm »

Big Red Machine · « **Reply #14 on:** 19 Oct 2009, 01:22 pm »

Quote from: mathgeek97 on 19 Oct 2009, 01:06 pm

Funny! Can I copy that photo?

You'll probably crack your eardrums with high power amps before the speakers fail. Underpowered amps will clip and damage your crossovers if driven too hard. You are fine with the Wyred or the Spectron on Salks.

charmerci · « **Reply #15 on:** 19 Oct 2009, 02:25 pm »

Unless you crank it up on the alarms on Dark Side of the Moon's Time.

Blew out a Klipschorn tweeter that way.

TomQ · « **Reply #16 on:** 20 Oct 2009, 03:30 am »

I have the H3's with a parasound A51, drove so hard last summer the amp shut down, was playing above reference, probably 90-100 db's for 1 hr, before it suddenly stopped. Speakers never had problem. but amp overheated.
At normal ie 60-75 db for TV, Movies or music never a problem. I really like the parasound Halo A 51, 250 amps per channel, the sound is great, especially the mid range. I use a integra 9.8 pre with music going from a imac to a squeezebox feeding a van-alstyne DAC to balanced inputs on the integra to the parasound to the H3's. No processing use direct on the integra. T

oneinthepipe · « **Reply #17 on:** 20 Oct 2009, 03:45 am »

OgOgilby and I played a loud, bass-heavy track from a demo CD that caused the woofers on his HT2-TL to reach their maximum excursion, I assume, and distort. We were playing the track fairly

loud in OgOgilby's large listening room. We both wondered if the problem was his amp, before he got the Parasound A-21, but I took the CD home and played the track in my little room, and I had the same result.

However, this was very deep and very loud bass, and this was the only time that I ever heard the woofers distort. The level was louder than either of us would ordinarily listen to music.

No damage was done to equipment or man.

Since then, I have come to accept that there is a role in this world for subwoofers. (Unless you own the HT4.)

TomQ · « **Reply #18 on:** 20 Oct 2009, 04:01 am »

oneinthepipe, I also use a Marantz CD5001 and an imac as music source, I was comparing both run through the AVA insight DAC, I preferred the DAC to the direct from either the marantz or the squeezebox. The AVA DAC sound was clean, especially the high and mid range, regardless how much I increased the db, but without the DAC the sound was distorted at increased levels,the AVA DAC added a new dimension to listening to music. T

oneinthepipe · « **Reply #19 on:** 20 Oct 2009, 05:29 am »

Quote from: TomQ on 20 Oct 2009, 04:01 am

oneinthepipe, I also use a Marantz CD5001 and an imac as music source, I was comparing both run through the AVA insight DAC, I preferred the DAC to the direct from either the marantz or the squeezebox. The AVA DAC sound was clean, especially the high and mid range, regardless how much I increased the db, but without the DAC the sound was distorted at increased levels,the AVA DAC added a new dimension to listening to music. T

I generally run the digital output from the Marantz CD5001 into an AVA Insight+ DAC, and I generally run the digital output from the iMac into an AVA Transcendence 8+ DAC, then the DACs feed into an AVA Insight+ preamp's analog line inputs. I have never listened to the iMac's analog output, but I suspect that the sound quality is very poor. I have listened to the Marantz's analog output, and I was unimpressed. The Marantz is cheap, and perhaps noisy, and I have been unsuccessfully trying to persuade the salespeople at the Sony outlet store to sell me a 9000ES-something (2999.99 retail) that has been collecting duct, unconnected, for more than a year, for a vastly reduced price. Thus far, they won't sell it to me. I don't want to spend a lot of money on another CDP because I am transitioning to a computer-based system for digital music, and I listen to vinyl, too. I wouldn't be surprised if CDP sales continue to nose-dive.