Low-power loudness from a 25 mm speaker

[Neil Davis]

Since the numbers don't work out for linear processing, I think you will need to use some DSP algorithms to achieve the "appearance" of high output.

The Analog Devices "SuperBass" algorithm really works: it gives the impression of deep bass without a lot of amplifier power. It is a "psychoacoustic" algorithm that creates harmonics of the fundamental, thereby "tricking" the ear into thinking that there is additional bass. I've tried it, and it works as advertised--it sounds like there is a lot of bass, even though there is relatively low cone movement. There are some artifacts that make this algorithm undesirable for "hi-fi", but it should probably work well for speech.

Other useful algorithms would be in the nonlinear compression group. By using dynamic range control, you can sometimes give the impression of high volume without exceeding the maximum excursion capability of the driver.

I suggest getting a low-cost ADAU1701 DSP board where you can evaluate some of the free algorithms in the Analog Devices library. I think that is going to be your best path to getting the most effective output from the driver you have selected.

 

[PRR]

> I have no idea how I am supposed to do this to a voice file!

Well, it can be done in the analog circuits. But a file can EASILY be processed.

You seem to be talking past all questions and answers.

 

[twenty20]

Since the numbers don't work out for linear processing, I think you will need to use some DSP algorithms to achieve the "appearance" of high output.

The Analog Devices "SuperBass" algorithm really works: it gives the impression of deep bass without a lot of amplifier

This is very interesting, and may prove useful at some point. For now, though, I am not interested in bass. It is only human voice.

I suggest getting a low-cost ADAU1701 DSP board where you can evaluate some of the free algorithms in the Analog Devices library. I think that is going to be your best path to getting the most effective output from the driver you have selected.

If it comes down to doing analogue design, I will look into this.
Thanks much.

 

[twenty20]

> I have no idea how I am supposed to do this to a voice file!

Well, it can be done in the analog circuits. But a file can EASILY be processed.

Thanks!

You seem to be talking past all questions and answers.

As I gave a very detailed, almost point-by-point response, could you please give an example of where and how I erred. Thanks.

 

[OllBoll]

I'll look up its specs, but I'm assuming that the 4.5mm is the maximum outward displacement of the cone, resulting in
5.31 sq. cm * 0.45 cm = 2.4 cu. cm.

I don't know how you got the numbers below (ie the exact formulas for the relationships between volume displacement, SPL and dB) but I'll take them on faith:

I used Linkwitz spreadsheet to calculate how big drivers you need for X ideal output. Designed to calculate how big drivers you need for dipole bass, and has a nifty comparison to monopoles which is what we want to use here.

 

[twenty20]

I used Linkwitz spreadsheet to calculate how big drivers you need for X ideal output. Designed to calculate how big drivers you need for dipole bass, and has a nifty comparison to monopoles which is what we want to use here.

Thanks so much.