Warning - LONG POST....
Those who read this board regularly would be aware I have been extremely sceptical of the motives behind Nice One's posts. Every post effectively talks down the value of AKP's technology, sometimes it's done very subtely, so to promote an appearance of objectivity while carefully planting doubts that our chips won't be cheap enough, loud enough, or the right frequency. The last post is a cracking example:
"So if they could make them cheaply enough"
"this is the challenge they face I think to get the speakers to make enough noise at lower frequencies".
"So maybe with more R&D they can make these work better at low frequencies"...
I have copped some criticism for holding this view of Nice One but I have seen this behaviour many times before. I think we all agree that Nice One possesses far more technical knowledge than most/all of the other posters on this forum. His posts have the ability to cause considerable fear in investors’ minds. Most of the free float in this company is in the hands of regular PIs - many of which read this forum, so his negative posts can have a dramatic impact on the share price. I will always question why someone who is not invested would invest so much time on any forum. Those who think he has a genuine interest in AKP’s technology must overlook the fact he has never spoken with our scientists by phone even though they are readily accessible. I note Nice One has conveniently ignored my plea to pick up the phone and call them - Nice One please do so then come back to us...
Over the weekend I caught up with one of the company’s major shareholders (Top 40). This chap is one of the reasons why I invested in the company in the first place and he has a deep understanding of the technology. He does read the Hotcopper boards from time to time but isn’t the type to post and has also asked to remain anonymous. He shares the same view of Nice One. I asked him if he could answer Nice One’s two questions from a week or so ago:
- Is the Typical Mobile Phone Micro-Speaker line on the chart you have provided in the Preliminary Results representative of SPL at 0.1Watts at 0.1Metres or is it Max SPL. 2. Are the AP speaker actual and theoretical lines representative of Max SPL or benchmarked to another SPL below maximum? If below maximum, by how much in dBs.
The answer went over my head at first because I didn’t understand a few fundamental concepts so let me map those out first:
SPL – Sound pressure level – The standard for measuring loudness of a sound wave. As everyone knows, the closer you are to the sound source, the louder it sounds. It is therefore important to provide the distance at which the SPL is measured, as without a distance figure any SPL measurement is meaningless.
Sensitivity – a measure of the speaker efficiency – describes how much acoustic power one can get by driving the speaker at a certain electrical power. A high sensitivity speaker can produce louder sound using the same electrical power and would therefore consume less battery power to deliver the same acoustic results. The typical units of measure are SPL at 1 meter per 1 Watt or in the case of most micro-speakers SPL at 10cm per 1 Watt.
Max power – the maximal continuous electric power (Watts) the speaker can handle without damage. Most often the speakers’ usable power range is far lower as it begins to sound bad well below the damaging threshold.
There are two industry standards for SPL measurement – 0.1m (used mostly by mobile phone and micro-speaker makers) and 1m (almost everyone else). The conversion between the two standards is simple. Measurements at 0.1m are 20dB louder than measurements at 1m. In general, the formula for converting the SPL at distance X to the SPL at distance Y is: SPLY = SPLX + 20*log10(Y/X)
However some speakers cannot handle 1 watt of power, in which case the SPL figures shown on their performance graphs are only theoretical as they can never be reached (certainly not without damaging the speaker). On the other hand, many larger speakers can handle several Watts (or even hundreds of Watts). In such a case, the maximum SPL the speaker can deliver would be much higher than the SPL at 1 Watt. To deduce the actual SPL the speaker can produce at its maximum power, use the following formula: SPLmax = SPL1Watt + 20*log10(Pmax)
Example:
If a speaker has a sensitivity of 90dB/Watt @ 10cm and can handle 0.5 Watts, the maximal SPL would be: SPLmax = 90 + 20*log10(0.5) = 84dB. To figure out the SPL at 1 meter, subtract 20dB so the result is 64dB at 1 meter.
In the eyes of our major shareholder the AKP plots did in fact tell us everything we (and industry) need to know. No information was conveniently left out as implied by Nice One.
So to answer Nice One’s questions:
1.To plot the typical micro speaker curves, AKP would have taken a sensitivity plot for a micro speaker at 10cm and 1 Watt, then subtracted 26dB to get the SPL at 1 meter and 0.5 Watt (the maximal handling power of a typical micro speaker).
2.The AKP comparative line charts would be normalised for an apples to apples comparison to show the actual maximum SPL at 1m.
Next question Nice One and I’ll see what I can do.
(20min delay)