Wednesday, January 28, 2009

New Ultraefficient Audio Amplifier Technology

Audium Semiconductor Ltd. (Bristol, England) has raised $8.5 million in a first round of funding. The company claims to have proprietary audio power amplifier technology that requires one-twentieth (1/20) of the power of competitive Class D amplifiers at "normal listening volumes."

This is written on Audium's website:


Today’s audio power amplifiers only achieve optimum efficiency at full output power. Because a typical audio signal has a very high peak-to-average power ratio, amplifiers operate at less than optimum efficiency most of the time.

Audium’s amplifier technology changes all of that by dynamically adapting the DC operating conditions of the amplifier to ensure that it’s always working at peak efficiency.

Benefits include a 20X reduction in power consumption at normal listening levels*, smaller form factor and a saving on heat sinks. What’s more, the Audium advantage increases with the amplifier output power.

*Normal listening level is defined at 70dBC SPL at 1m with a speaker sensitivity of 89dBC/W/m.


Their technology appear to be geared mainly for portable audio, but they do have products with 100W/channel peak power output. The applications mentioned include battery powered MP3 docking station speaker systems and totally wireless speakers for home and PC audio. Obviously, both of these applications would benefit from more efficient amplifiers.

Here's my question: How do they sound?

I can't find any performance specs, other than peak power output and frequency response. No noise or distortion stats. I doubt these are really intended for high fidelity audio.


  1. This announcement strikes me as not really very interesting to most audiophiles. Doing the sums on the SPLs they're citing, the average output power under consideration is about 11mW. So their amp is 20X more efficient when outputting 11mW - I have to say that's rather underwhelming ;-) Even with 20dB peak-to-average ratio music, this represents an amplifier power rating around 1W. Who buys a 100W amplifier only to run it as though it was a 1W amp?

    I'm working for more than 20 years in electronics design. I've ordered hundreeds and hundreeds samples, not a single "normal" firm asked me money for them! This one (Audim) asks money for them! In the site they wrote: "Samples are available now, priced from $8 each in 1000+ quantities" ( Imagine, they want to sell their samples in quantities of 1000 at a price of $8. Who is the freak that will order 1000 samples of a product without any datasheet? More than that, it is an UK based firm and they are asking to pay them in dollars, but they do not mention what dollars! Australian? Canadian? Hong Kong? Singapore? US? Or maybe fraudulent dollars!