Low power amps on speakers

[Fish]

I have had some speakers for decades that still perform as new, played crazy long hrs. The only speakers I ever ruined was by under powering them and blasting them at a party for hours. I've ruined a few sets that way in my youth. .I would say it's a true statement many more speakers are ruined by under powered amps. I don't think it's the low power but the overdriving  amp long term. So another vote for sorta BS.

[MEH Synergy]

27 minutes ago, Fish said:

I have had some speakers for decades that still perform as new, played crazy long hrs. The only speakers I ever ruined was by under powering them and blasting them at a party for hours. I've ruined a few sets that way in my youth. .I would say it's a true statement many more speakers are ruined by under powered amps. I don't think it's the low power but the overdriving  amp long term. So another vote for sorta BS.

Interesting that two people that have blown tweeters by clipping amps due to underpowering say that the statement is BS.  I have never blown a driver by overpowering. Common sense says if you have a 100 Watt RMS power handling speaker, you don't try to fill a large room with high SPLs because you have a 500 Watt RMS amp either.... 

[Emile]

6 hours ago, garyrc said:

how big is your room?

Gary,

 

Thanks   Room is about 15x25x10 so 3750 cu ft.  One side, and about 1/3rd of the back, is open to an area about 10,000 cu ft.

Haha ... re the "don't let people near the volume control" ... They always try to turn DOWN my volume levels   ... Interesting note on the R2R's; didn't know that (guess I never did it on "loud"

 

Thanks, Emile

[Emile]

2 hours ago, Marvel said:

Here is some info from two folks on the forum I respect

Marvel, Thanks a lot for the GREAT info!

[MeloManiac]

"To give you the best balance of power and performance, select an amplifier or receiver that delivers continuous watts (many times erroneously referred to as “RMS”) in accordance with the speaker’s rating.

For example, a Klipsch RF-83 floorstanding speaker is rated at 250 watts. So, any amplifier that delivers 250w/channel would be a good match. Don’t be misled, by the way; although a speaker’s peak power rating can be much higher—in the RF-83 example, it’s a whopping 1000 watts—remember that peak power means exactly that…a momentary exposure. Trying to make any speaker perform for more than an instant at peak is to invite disaster!

The right amplifier, one that has its power well matched to the speakers, will also eliminate the need to overdrive components, which can induce clipping, which at best distorts the signal and at worst can cause serious damage. Believe it or not, underpowering speakers carries as much danger as too much power. 

Horn-driven speakers, such as Klipsch, are much more efficient than their direct radiating counterparts, and require less power to create great sound. Just be sure to keep the receiver’s output closely matched to speaker specifications to ensure years of trouble-free performance."

source: https://www.klipsch.com/support?guideTitle=Receivers-and-amplifiers&guideId=ccc343a6-14bb-4a2f-b2e4-50a42b5deae6

[Marvel]

9 minutes ago, Emile said:

Interesting note on the R2R's; didn't know that (guess I never did it on "loud"

Many RTRs don't didn't have tape lifters, or wouldn't lift the tape far enough from fhe jeads when fast forwarding or rewinding the tape. This would cause extremely high freq. to be fed through the sys to the speakers. Not healthy for the tweeters...

[Marvel]

2 hours ago, Westcoastdrums said:

That is false.  So he is saying if you have a 5 wpc and input that into say a pair of 88 dB sensitivity speakers that the tweeters won't blow because they didn't receive "excessive long term average power, not clipping."  BS

 

I'll go with the two engineers, thanks.

[MEH Synergy]

20 minutes ago, Marvel said:

 

I'll go with the two engineers, thanks.

Just so I'm clear, you agree that clipping an amp purposefully into a tweeter will not result in damage so long as it doesn't receive "long term excessive power"? 

[Marvel]

That's what they said, right? Do you think my amps have never clipped?

 

I knew Dennis for over 30 years and trust what he said (most of the time... but different topics ...)

[MEH Synergy]

I didn't say an amp clipping will result in destruction. However, an amp continously clipping will.   I do agree that overdriving drivers long term will result in similar damage as well.   If that were to be false, the clippjyn part, why are there clipping indicators on pro amps?  Shouldn't matter if they clip then as long as you are under powering, you should be fine 

[MeloManiac]

I'm learning a lot here, so I thought I 'd share this video which explains why clipping is a bad thing:

https://www.youtube.com/watch?v=9PF32APSjrk

[MEH Synergy]

6 minutes ago, LeftEyeShooter said:

this video which explains why clipping is a bad thing:

What, now it's a bad thing?   Come on..... 

[Ski Bum]

2 hours ago, Westcoastdrums said:

I didn't say an amp clipping will result in destruction. However, an amp continously clipping will.

Not exactly.  It's true that a continuously clipping amp will dramatically increase the average power and thus also the likelihood of damaging a driver, but if the power delivered from the continuously clipping amp is below the driver's limits, it won't fail.  (Those of us using flea watt amps aren't frying tweeters, and we clip our amps plenty enough.)  Ultimately, it's the power (applied over a specific amount of time) that melts voice coils and kills drivers, whether that comes from a continuously clipping amp or not.       

 

Re-read the quoted material from DJK again, it's spot on.  HERE is another reputable source saying much the same.

 

[babadono]

Again I say a watt is a watt is a watt.

Excessive clipping can be what causes the average power to rise beyond the power rating of a given voice coil.

But a 1 watt squarewave fed into a 10 watt voice coil makes it fail, ah no.

[robert_kc]

My Inspire “Fire Bottle” SE Stereo Tube Amplifier HO (single-ended tube amp) puts out approximately 8 wpc when equipped with 6L6GC.   It sounds good driving my Klipsch RF-7II, except for music with tremendous dynamic range (i.e., large scale orchestral music).   When this SEP amp "runs out of gas" it doesn't sound bad, I just don't get the full fff dynamic impact.

 

I've never damaged a speaker.

[Panelhead]

  Solid state amps do not all react the same way to being overdriven. The recovery time and stability can be optimized. Fast settling time can be a design goal.

  I doubt if most horns see a clipping amplifier. 1 watt is loud enough.

[seti]

I've run .5 to 12wpc on Belles, Khorns, and Jubilees. Never hurt them. What if I tried them on some POS 85db speakers... Perhaps. My fave so far are .5 to 2 wpc 45/2a3 on jubs.

[HPower]

On 1/31/2019 at 8:36 PM, Emile said:

Hi All,

 

Just wondering if "low power" amps hurt speakers.  Had been discussing this with CrutchField, etc ... and they said low power will damage your speakers. (In my case, have a set of KPT-904's ... recommended minimum is 800W/ch ... used to drive them with a Marantz 2252B at 52W/ch, but now trying a Crown K1 at 350W/ch ... not sure if it sounds any better ... though think it's a "yes.")

 

Know many of you (myself included) have driven Klipsch speakers with 1-5 Watt tube amps (and also low Watts SS amps). I never had a problem   

 

So; any truth to this or are "they" just trying to upgrade us to bigger amps?

 

 

 

 

Ya,

but my speakers are rated at a minimum of 800 Whats per channel. 😎

Look at sensitivity, and let logic dictate

[MeloManiac]

Ken Rockwell:

"[Tube amp] waveforms are highly asymmetrical because each old tube was quite different from the others, but the key here is that even though they are clipping, there are no sharp edges to the waveform. (This old amplifier and its weak old tubes still sounded fantastic at normal levels.)

When a solid state amplifier clips, there is a sharp edge where it looks like someone simply took a pair of scissors to the tips of the waveforms. The sharp edges of solid state amplifier's waveforms at clipping give rise to insane levels of very high order ultrasonic harmonics, which are what blow out tweeters."

Source:  https://kenrockwell.com/audio/why-tubes-sound-better.htm

Ken also has some nice waveform pictures to illustrate this.

 

He also explains this: "Tube power amplifiers are usually rated for the power you actually need and will use, like 8 to 80 watts per channel. Solid state amplifiers tend to be rated up to stupid and dangerous power levels as prices increase. No one needs or uses 300 WPC except public address systems; 300W will melt any single speaker. Sadly not only do you wind up paying for and having to lift these solid state beasts, they sound even worse down at the rational levels at which you will actually enjoy them. [...] Don't let me stop you if you want a 100 WPC amplifier, but you don't need it unless you like to crank it, have a big room or inefficient speakers, or enjoy very wide dynamic range classical music at concert-hall volume."

 

(This reminds me of a friend guitar player who loves his 15W tube guitar amp much better than his 45W amp: the small one opened up at the volume he needed to play, while the 45W opened up at a volume that was much too high for the venues they were playing...)

Edited February 2, 2019 by LeftEyeShooter