old wives tale / myth

[jer446]

i was just wondering, growing up when i would play music to loud my dad would say turn it down, your going to blow out your speakers! I was wondering if this was a myth, because now that i am older, and i take electronics, im pretty sure it isnt possible because the manufacturer wouldnt design it that way and really isnt changing voltages.. please confirm my suspicions lol..

 

[ohcrap]

Um, are you asking if speakers can be blown?

If so, the answer is most definitely. Most "boom boxes" are designed to prevent the included speakers from blowing (melting voice coils, and/or other mechanic failure) by significantly underpowering the speakers.

 

[andiwm2003]

most amplifiers have crappy electronics in there. when you overpower the amplifier you get a constant current. your speakers are not designed to withstand a constant current heating up the coils. they can actually get damaged even if they are "underpowered".

 

[revisionA]

if you want to play it loud, get speakers with built in Limiting. This protects them from excessive levels. I use a pair of Krk v8 studio monitors that cost about $1000, so they both use kevlar instead of paper for the cone, and have built in power, limiting and even a crossover switch. For the price, it should come with my own minime.

$

 

[SummerBreeze]

I blew a very old pair of speakers when I was about 12 years old. They were in my room, but I wanted to hear them outside while I sat in the Jacuzzi....Although I did convince my parents to buy me a new stereo afterwards under the stipulation that I play my music more quietly.

 

[devilot]

Haha, in my old '88 Volvo sedan I blew out one of the speakers. Dunno if it was really my fault or if it was already doomed to fizzle out...

 

[PCMacUser]

The people I've spoken to at hi fi shops have said that speakers are blown by connecting them to underpowered amplifiers. I don't really know what qualifies as underpowered though.

My advice is to not turn the amp up too loud so you can preserve your hearing. Who really cares about speakers. They can be replaced!

 

[kgarner]

Basically if you mismatch the max power of the speaker with a more powerful amp you can blow your speakers. In most of today's systems where the speakers are built-in to the unit it is most likely not a concern. But when using a seperate amp and speakers it can be a concern.

 

[ScruffyTheMac]

The people I've spoken to at hi fi shops have said that speakers are blown by connecting them to underpowered amplifiers. I don't really know what qualifies as underpowered though.

That is correct - trying to get high volume from an amp with insufficient power will cause 'clipping'. This induces high-frequency transients that can blow up speakers.

If you hear distortion as you increase the volume, you are probably clipping. If the sound is clear but your ears start to hurt, then you have enough power.

 

[eRondeau]

Clipping Bad...

That is correct - trying to get high volume from an amp with insufficient power will cause 'clipping'. This induces high-frequency transients that can blow up speakers. If you hear distortion as you increase the volume, you are probably clipping. If the sound is clear but your ears start to hurt, then you have enough power.

I've got a wonderful 15-year-old NAD 3240PE ("Power Envelope") amplifier that has a switchable "soft clipping" feature. Not 100% sure, but the idea is that it somehow electronically smoothed-out the clipping distortion to protect your speakers. Plus, it has extra-large capacitors so it was briefly able to deliver far more than its rated 40 Watts/Channel. A very sweet amp, that still sounds fantastic!

 

[ScruffyTheMac]

Yep - the static watts/channel power rating doesn't tell you anything about how well an amp behaves dynamically. Some modestly-rated amps can deliver fantastic clear sound at volume - especially if paired with efficient speakers.

 

[contoursvt]

Underpowered amps will kill speakers way sooner than an overpowered one. Reason being that when you exceed the capabilities of an amp (distortion), it cuts the tops and bottoms of the signal (lets assume a sinewave) so they get flat. The flat portions are essentially DC and will heat up the coils and fry them.

Here is a clean sinewave http://www.aw2spec.com/article/audio101/images/audio101_09.jpg

Here is a 'clipped sinewave http://www.aw2spec.com/article/audio101/images/audio101_10.jpg

Basically, with a very powerful amp, you will not 'clip' the amp, it will just get louder and louder until the speaker bottoms (you'll hear banging metallic noises in which case you should back off or you can physically damage the speaker but not burn the coils).

 

[jer446]

well for example, could i blow my speakers in my stock stereo for my car??So if i dont change them and leave the stock amp, does that mean i cant burn them out? What about computer speakers hooked up to my imac? And anything else that is stock like my stereo in my room, with the amp that came with it, can those be burnt out?

 

[ScruffyTheMac]

The answer is: probably. So, don't turn the volume up past the point where you start to hear distortion, which is the sign that clipping is starting.

 

[Kup]

I don't think there is a speaker on the market that can claim to be incapable of being blown. Just look at Marty McFly in Back to the Future.
Just use comon sense when it comes to volume levels.

 

[clayj]

The answer is: probably. So, don't turn the volume up past the point where you start to hear distortion, which is the sign that clipping is starting.

Echoing what others here have said... my old manager at Radio Shack was fond of telling customers that it's not too much power that kills speakers, it's distortion that kills speakers.

 

[revisionA]

I really love watching the cones wobble in time to the music while I exhale a stream of deep gray smoke....

until the bass bounces my pyrex off the desk onto the tile.... lost 3 so far to unplanned high volume escapades...

360 total watts of pipe destruction!

 

[stridey]

Echoing what others here have said... my old manager at Radio Shack was fond of telling customers that it's not too much power that kills speakers, it's distortion that kills speakers.

That and feedback loops. Doesn't really happen with speakers for a stereo very often (because you rarely have a mic input), but feedback will essentially try to push the cone out infinitely far, which results in torn speaker cone. It's a sad, sad, thing to witness.