Should amplifier output be restricted to the max power rating of the speaker?

[marin.weigel]

is there a link that could help explain what this means

Here's just one of many online voltage divider calculators, respective resistors are small enough to be integrated into the connectors.

 

[john61ct]

I'm asking more like "for dummies" ELI5, like what is it, what is it for, why do it, what are side effects?

Are there built OTS enclosed products that do the same thing?

 

[somebodyelse]

I'm asking more like "for dummies" ELI5, like what is it, what is it for, why do it, what are side effects?

Are there built OTS enclosed products that do the same thing?

The off the shelf items are called inline attenuators. You can get them in a variety of attenuation values. They're typically used to get a better match between a high level output and a sensitive input.

 

[john61ct]

Isn't it better to avoid reducing the signal ALL the time though? The goal being to enforce a maximum level without interfering otherwise?

 

[somebodyelse]

Isn't it better to avoid reducing the signal ALL the time though? The goal being to enforce a maximum level without interfering otherwise?

In an ideal world maybe. When used properly they measure as transparent which is better than most active limiters, and they're inexpensive. They have the same impedance matching issues and potential interaction with cable capacitance as a 'passive preamp' so need to be used accordingly.

 

[marin.weigel]

Isn't it better to avoid reducing the signal ALL the time though? The goal being to enforce a maximum level without interfering otherwise?

If done properly, there's no audible interference to worry about.
It's the best and safest solution for the OP's requirements, nothing more, nothing less.

 

[john61ct]

Well I'm asking wrt planning for my system, not just advising OP.

In an ideal world maybe. When used properly they measure as transparent which is better than most active limiters, and they're inexpensive. They have the same impedance matching issues and potential interaction with cable capacitance as a 'passive preamp' so need to be used accordingly.

Maybe better to move my diversion over here

So why are clipping indicators not standard on amplifiers in 2026?

Limiting isn't necessarily better than clipping. As you turn-up the volume the peaks are limited (or clipped) but the overall average power still goes-up and it's the short-term average which overheats voice coils. Limiting might be worse since the distortion is harder to hear...

www.audiosciencereview.com

 

[pablolie]

Too little power and clipping ain't the best for speakers, either.... riddle me that.

 

[pablolie]

... That's a common myth. You can damage a speaker either way, but more power is worse.

Not sure why u would claim that with a high level of conviction. IF you match highly efficient speakers with very high powered amps (easy to do these days) and you ignore that mismatch... come on. Plenty of very audible warning signs. That may not be the case with an underpowered amp that can easily blow your tweeters.

 

[Torin Krell]

The power limits you are quoting are thermal limits. I.e the amount of heat generated by that power level, above which voice coil will be damaged through over heating

Excursion limit is frequency dependent. Above a certain frequency thermal limit takes over but below that less power than the thermal limit will actually cause the driver to exceed xmax. Dependent on driver the xlim may just be beyond or way beyond xmax. The spider usually limits travel but depending on backplate design the coil can smack the backplate.

For a 3: way speaker a rule of thumb is 10/30/60 % power spread across T/M/W drivers

It depends on your average volume level too. Allowing for 10-20dB headroom. Means 10 to 100 times reserve power. So an average 1w/1m at 86dB can be power limited at 106dB with a 200w amp

More is better imho. Just use your ears and listen for distortion

Agreed - Before I started a business providing live sound, while in college, I did extensive real life experiments into what would destroy conventional cone shaped speaker drivers. I drove several speaker drivers with bandpassed filtered music and sine waves (while wearing ear protection) to destruction and found the following:

Below the lower midrange, damage from over excursion usually caused the former to hit the backplate (especially if the driver was not loaded properly) jamming the driver in place as the former was damaged/crushed preventing it from moving in the magnetic gap.

The midrange frequencies were actually tolerated the best as the excursions were more limited than in the lower frequency trials, preventing mechanical damage, and the mid frequencies apparently provided more ventilation to the former/voice coil assembly than the high frequencies in the high frequency trials. Beyond a certain level however the glue holding the voice coil on the former would melt, char, and/or vaporize delaminating the voice coil and jamming the former/voice coil assembly in the magnetic gap.

High frequencies (although usually at a lower level in music) when pushed with the same amount of watts as in the mid frequency trials actually damaged the drivers sooner than mid frequencies (although with similar damage) apparently because driver motion was rather limited and did not provide any cooling to the voice coil and former. (If I had used tweeters instead of cone drivers there likely would also have been other types of damage such as the coil actually melting as tweeter wire is significantly thinner - however my experiments were limited to cone drivers.)

Although I conducted these experiments many years ago I clearly recall the equipment used: Soundcraftmen MA-5002 amplifier, (with crowbar protection circuit), Crown VFX2A crossover, Moog Minimoog synthesizer, and several scavenged cone drivers varying between 4" to 8".

I also recall that all these blisteringly loud trials made me rather unpopular with my neighbors on that summer Sunday afternoon.

 

[pablolie]

Team plenty of highly recommended amps and speakers these days are seemingly incompatible on paper. How many spectacularly measuring 200W+ amps are out there? Plenty of very smart people in here fervently advocated -as an example- the Benchmark AHB2 matched with LS50 Metas as a perfect match despite the potential power envelope mismatch. I had the combo for a bit and it didn't take a genius IQ to know you could not turn the volume on the Benchmark DAC2HGC beyond 10am...(went from 7am to 5pm on the DAC2 volume dial)

 

[Torin Krell]

While the theory is solid about no underpowered amp should toast a speaker, practice shows otherwise.

Just a look at these old "all-in-one" systems with their joke of an amp and the tiny percentage of the surviving tweeters are enough evidence.
Square waves are not a good idea.

Agreed! Lower powered amps when clipped often produce more power than they are rated at and also produce more high frequencies (square wave harmonics) which together can easily result in tweeter damage.