Thermal Distortion your loudspeaker most likely suffers from it. But do you care?


 Thermal Distortion is much more serious than just a maximum power handling limitation or side effect.TD is overlooked by most manufacturers as there is no easy (low cost) solution and TD is audible and measurable most of the time at most power levels. TD is caused by the conductive metal (aluminum, copper, or silver) voice coil getting hotter when you pass electrical energy through it. The more power you pass through it the hotter the metal gets. The hotter the metal gets the more the electrical resistance increase. The efficiency goes down and you need to ram in more and more power for smaller and smaller increases in SPL. It can be the reason you get fatigued while listening. If you are running massive power you are creating more TD in your transducers. But do you care? And is it a reason some prefer horn-loaded designs or SET-powered systems since they have the least problems with TD? 

128x128johnk

I never gave this much thought, intersting....I’m seemingly driving my Tannoy Eatons with 30 watts of Sugden class A, and I can’t get past 11 o’clock on most if not all material. Plenty loud for me and my room. 

@johnk Said,

Thermal Distortion is audible and measurable

I agree!

I thought about thermal distortion (TD) some 45+ years ago. My speakers are designed to have a power linearity of < 1 dB of SPL compression output from 1 watt to 100 watts and their efficiency is 2.7 %.

 

Mike

Here is a good article on the subject.

 

 

what about low efficiency planar speakers like apogee scintilla, it seems like they would dissipate heat better.

It’s also part of the sound of interconnects.

Besides the problem of the given audio cable having it’s most perfect impedance at exactly one frequency and one frequency only.

Where all other frequencies are imperfectly handled and are converting to heat and distortion in the phase realm or time realm. smear. noise.

When we turn up audio systems, it is also happening in the cables (eg, preamp to power amp and speaker cables), where they get overloaded and they reach a certain threshold of distortion vs clean, and we hear it, like a crunchy noise or transient smear aspect. that’s cable screech and we all dislike it. A well designed cable has the least of it as is possible. Or some mud it up, and achieve being comfortable at the cost of all other aspects of signal clarity. All cables are compromises designed for the hearing of individuals with individual gear. That’s why there are so many brands and designs.

That is part of what we complain about when we say that passive preamps are not as good as active preamps.

The most linear of all in this area of technological challenge across all levels of loading, is the liquid metal audio cables. We’re talking a good minimum of a magnitude better, to the point that all complaints are pretty well entirely gone and people relax into realism. There is a reason that our now closed Hong Kong Distributor, who was active in and describable as the peak of the Hong Kong High end scene (no small thing, that!), called our best cables ’the biggest most important positive change in audio, of all time, in all technological areas of audio’. The only way to know if it is, or not...it is to try them out.

 

It's also difficult to imagine ahead of time as all things ever made utilize wire and solids. It’s a huge deal. Literally. How can one understand the existence of being a box when the lexicon of ’box’ and ’external to the box’ has never before been elucidated, whatsoever? Paradox. It’s simple. Just listen.

We also produced a liquid metal passive preamp, that threw those complaints about passive preamps out into the street, we banished them. Those who have tried it, and are chasing down the ghost dragon of perfection (it’s not a math problem! Careful!) ... tend to think it is superior to all preamps, passive or active (at any price).

PS, if you ask why were' not on everyone' slips and in every one's system(if we're so dang odd, like I say, pfffft...), well it is jungle out there ....and we don't have a million dollars to spend on advertising and reviews, so that we can make $100k on the vanishingly small group who do actually recognize and seek the best.