Wrong. Please debunk yourself by searching posts from likes of Agedhorse and Bob Lee, both engineers for major US amplifier makers.
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Overclocking cabinets...
- Thread starter Eschaton
- Start date
I personally have blown up 3 of the 4 15" speakers in a pair of Sunn Model 15 pA cabs (8 ohm 200W) with a Neptune 215 power amp (80W per side into 4 ohms) while I was running the amp in severe clipping for an extended period of time. Anecdotal but true.
80W per side is specified at some (typically very small) THD.
It is not the maximum power available.
It's fair to say maximum power available was in excess of 200W.
This matches all the observed phenomona...
@agedhorse & @Bob Lee (QSC)
Would you guys mind chiming in and finishing my scolding for my understanding of how clipping damages speakers. i believe what I am referring to is over powering a speaker due to clipping an amp. Over powering in general is bad but an amp with a 500 watt rating can still blow a speaker with a 500 watt rating by clipping and sending it too much power. Am I wrong? You could compensate by having a speaker double the wattage of the amp but then you could just run the amp into clipping a bunch and it wouldn't sound good in the first place. A higher wattage amp can deliver whatever optimal wattage to the speaker. The only issue there is you can over power the speaker before the amp clips in which case, you'd need to use your ears to determine if you are doing damage to your speaker. Correct me. I have been running under this researched idea for some time. I've blown speakers with low wattage amps as well as high wattage amps. I haven't blown a speaker since I got both high wattage speakers and amp plus high efficiency speakers. They get loud before I even send too much wattage to them.
Would you guys mind chiming in and finishing my scolding for my understanding of how clipping damages speakers. i believe what I am referring to is over powering a speaker due to clipping an amp. Over powering in general is bad but an amp with a 500 watt rating can still blow a speaker with a 500 watt rating by clipping and sending it too much power. Am I wrong? You could compensate by having a speaker double the wattage of the amp but then you could just run the amp into clipping a bunch and it wouldn't sound good in the first place. A higher wattage amp can deliver whatever optimal wattage to the speaker. The only issue there is you can over power the speaker before the amp clips in which case, you'd need to use your ears to determine if you are doing damage to your speaker. Correct me. I have been running under this researched idea for some time. I've blown speakers with low wattage amps as well as high wattage amps. I haven't blown a speaker since I got both high wattage speakers and amp plus high efficiency speakers. They get loud before I even send too much wattage to them.
So I do understand that ratings can be measured an number of ways as well so saying that you have an amp rated at 500 watts matched with a speaker rated at 500 watts might really be more like a 700 watt total power amp into a roughly 500 watt speaker? Speakers must also be roughly rated as well seeing as there are different ways to get to the number. Eh?
Not true, the speaker will still move back and forth at the given frequency. Unless that square wave happens to be less than a few Hz, there's still plenty of cooling. The speaker doesn't go to the end of it's excursion and just stop there! Even at a 30 Hz square wave signal, in 1/60th of a second the voice coil slams to the other side of its excursion limit...then 1/60th of a second later, back again.
Bottom line, it's NOT the square waveform that damages speakers. It's overpowering the speaker, whether thermally or mechanically. Not the shape of the waveform.
It's not so much as there are a lot of ways to measure the power (which there are) but that all of the ways have the caveat "at x.x%THD".
The amp does not stop making power once its specified THD limit is reached. This is a fundamental component of the "tube sound" and the "tube watts" myth as well.
So if amp power is measured with mirrors, cab and driver ratings are specified with smoke & mirrors.
Especially since as you've observed, there's a mechanical travel limit, and a thermal limit, and they're almost never the same.
One (or a small integer number...) of cycles of a voice coil slamming into mechanical excursion limit can permanently damage it. This is what we're constantly being advised to listen for.
It typically needs a lot more time for the thermal limit to be reached, but there always is one. Since it's harder to achieve, some manufacturers feel confident in simply using a stupidly large number,,,
I don't want to hijack this thread. Sorry sorry. I just thought I had a solid grasp on it. Companies just need to make ratings a more universal language and the simple understanding of how these things work together more operator friendly. It is a very confusing thing.
Just your understanding of square waves and speaker motion. Voltage plot wrt time is squared off. Says nothing of the speaker motion.
Except that the Neptune is 80W into 4 ohms and the cabs are (were) 8 ohms, and how many 200W cabs will blow up at 201W (or whatever)?
so there's really no way to determine whether or not an amp can blow a speaker without dramatically underpowering based on the given ratings.
A good speaker should have enough documentation to determine how it will function under various frequencies and power input. Some software programs can plot excursion versus power, given a speaker's T-S parameters.
Another thing that happened to a friend of mine was that his bass amp failed, went into high frequency oscillation, and blew the speaker. The weird thing was that the frequency was so high that the speaker couldn't respond to it, so most of the energy went into heat and fried the voice coil. I was there when it happened, there was just this faint high pitched whine for a bit and then nothing. What's that funny smell?
Which can happen sometimes when folks try to "upgrade" their amps by plugging in a newer, higher-spec op-amp; the different bandwidth product can turn a safe circuit design into a high-frequency oscillator. The "wannabe" audiophile thinks his amp has suddenly found a new "sparkle" when in reality it's trying to fry itself ultrasonically.
Okay, the short redhead can...no, wait...the tall blonde can...no, that's not it...you can't get theah from heah.How would we ever provide analogies if cars did not exist?
Huh? Care to phrase that properly? Otherwise it reads like you just learned nothing. Mildly underpowered rig may be overdriven into overpowering the speakers. The end.
No, I'd move to a different street. Preferably one with a speed limit of at least 100.
What kind of bridle are you using, round or flat?My carriage is drawn by a team of two horses. Will I be OK with a team of six??
Proper? I did. Wattage specs are blurry. Determining what amp a speaker can handle at full force without blowing up is tough. Super under powered amp can't hurt a speaker that is rated for much much higher power. I have learned things but the variables still skew a lot of the practcality behind the science. Input specs, total wattage output possible isn't ever measured because of distortion %, speaker specs, cabinet specs, air temp...haha humidity, wire age, wall power, the strings, tone, blah blah. Can a 1 watt amp cause a single 300 watt speaker to blap or burn up?
