I'm digusted, Mordaunt Short,cheapskates

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hmmm, why , oh why?

once your sub was down, how did you decide to use a loudness button to compensate for the lack of subwoofer? Loudness compensation is to attempt to overcome our ability to hear low frequency at low levels, not as an added "bass boost" as planet10 rightly points out. And because of this you may also have attempted to overdrive the woofer with inadequate power (which is far more damaging than having "too" much" power)--and may have damaged the woofers in your loudspeakers.

Here's my suggestion: go buy yourself some cheap headphones and blow them all you want, adding "loudness" and all the bass you want , too. A sub should add to the experience of listening to recordings, and if you feel the need to use loudness compensation to compensate for a dead sub don't do it. Perhaps the biggest mistake in audio was adding these controls (bass and loudness) to any audio device--because most abuse them as you have.

stew
 
Re: hmmm, why , oh why?

Nanook said:
And because of this you may also have attempted to overdrive the woofer with inadequate power (which is far more damaging than having "too" much" power)--and may have damaged the woofers in your loudspeakers.

Myth - you cannot damage woofers by underpowering them. Tweeters on the other hand are killable with clipping...
 
Well, diverting from the central subject and responding to MikeHunt79, a myth indeed.

You will read much about underpowered amps damaging speakers, but no one actually defines 'underpowered amp'. I've had several friends back in the day when we were partying, who could throw one heck of a blow-out party with a decent set of speakers and a 25 watt per channel amp. Most of my life I've had 40 or 50 watt per channel amps, and I've thrown some seriously loud parties too.

Neither they nor I have ever blown any part of a speaker in many years of partying. But, and here is the key, we understood the limits of our equipment, and as loud as we pushed it, we never pushed it beyond reasonable limits.

Consequently, I am here to tell you that it is always the guy running the volume control that damages speakers, and not over powered or under powered amps.

Or, so says I.

Steve/bluewizard
 
Another Helpful One

once your sub was down, how did you decide to use a loudness button to compensate for the lack of subwoofer? Loudness compensation is to attempt to overcome our ability to hear low frequency at low levels, not as an added "bass boost" as planet10 rightly points out. And because of this you may also have attempted to overdrive the woofer with inadequate power (which is far more damaging than having "too" much" power)--and may have damaged the woofers in your loudspeakers.

Loudness boosts bass a little, and as does turning up the bass control, this was done for 20 seconds worth of music, like I said, I don't normaly read this. I bet you loved saying
Here's my suggestion: go buy yourself some cheap headphones and blow them all you want, adding "loudness" and all the bass you want , too.

Then take the time to read what I said. I have a rev counter on my car and have pushed into the Redline on quite a few occasions, what would you say for a burst of Redline, "Ooh, watch your timing belt, don't want to do that do you."

What percentage of humans have done it? I got a buzz from a bit of bass in music, and the Music is what its about!

iUSERTLO72p
 
Mike Hunt, Blue Wizard and iUSERTLO72p

I've spent some time in retail of hifi, and I've smelt the results of some who have underpowered a loudspeaker. Take for example a speaker that has an efficiency of 86 dB. Apply enough power to push a 20 watt amp into clipping. Let the amp continue to clip. What's that smell? usually the voice coils of the tweeters starting to burn the formers. I've seen the results, and the customer looks alarmed as to say , "who me?" The same can occur with woofers, despite their larger voice coils. I agree the tweeters are most likely to go first.

So, to Blue Wizard: the key is "reasonable limits" as you quite rightly pointed out.

to Mike Hunt: spend some time in retail and observe what some idiots will try to get away with and then cry "warranty" when they damn well know they've pushed their amp into clipping (or else they didn't know which is equally dangerous)

and to iUSERTLO72p: most modern cars have a rev limiter built into the ECM. And if they don't, I agree an occasional "blip" past the red line may not hurt the engine long term. However an engine isn't made with paper formers that can easily become over heated from the overheated voice coils.

I have a friend, who despite being told to turn the bass down and switch off the loudness button, continues to push a nice little NAD "reference" series receiver way beyond it's limits. He just chooses to ignore my advice. And he pays the price, replacing blown tweeters quite often, and woofers occasionally.

I guess I think it is common sense to use a little discretion regarding tone controls and loudness compensation. adding 3 dB of bass and using a loudness compensation circuit good for 3dB can put demands on your amp up to 4 X's as much as power as without. And if that sends your amp into clipping , then at some point damage will occur.

Regarding the plastic baffled MS 40 speakers. When I did work retail we had a pair of Paradigm Studio 100 speakers returned to us. Upon opening the enclosure we found the crossover had literally been shaken from its panel, where it had been hot glued to the enclosure. Was this an end user problem or a manufacturing error? Don't know, but it does make me wonder what some folks expect of their systems. I agree, some sort of caulking (silicon or rope) should help with vibrations where the enclosure material and plastic baffle meet. A dampening pad on the plastic may also help. Please check the screws for tightness as well, as screws can loosen over time.



stew
 
One last point before this thread closes, and again, off on the secondary topic of amplifier clipping.

It is not so much amp clipping that is the problem, my amp clips all the time and never causes a problem. The real problem is severe and sustained clipping. Clipping at volume levels that are just unreasonably by any standard.

I set the volume limit on my amp at about 60% turn of the volume control, and believe me that is loud. Most often for a party, I am in the range of 40% to 50% turn of the volume control, and again, never in many years have I had a problem. In my case, most often I have been using 60 watt speakers with a 40 watt amp.

So, once again, I reassert that it is always the idiot running the volume control that ruins speakers, not over powered or under powered amps.

Two factors occur when an amp goes into clipping. The saving grace for speakers is 'dynamic signal'. Because the signal is constantly changing, there is time for the voice coil to cool, but if you push your amp into severe clipping, that is roughly the same as applying a 30 volt DC signal to the speaker. It is not going to sustain that constant current flow for long.

The second factor, and this is true of any AC power device, is asymmetrical signals. Because the amp output is swinging both positive and negative equally when in its normal operating range, the net power is zero. When you push and amp into clipping, again because of asymmetrical signals, a DC offset begins to form, and now you net power is NOT zero. Again, this DC offset over time can damage your most sensitive speaker which, most commonly, is the tweeter.

With that, I am out of here.

steve/bluewizard
 
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