Stereo Tool

Now available on the download page.

Changes w.r.t. version 3.30:
- Completely rewritten the Loudness filter.
It now has far less artifacts in the sound AND reaches a higher loudness. Also, it can handle loud bass peaks much better, so far less clipping can be used in the multiband compressor, which in turn leads to a more punchy sound.
- Improved Composite Limiter: Now uses oversampling to 768 kHz to better avoid peaks in the MPX output signal (peaks should now stay below 1% of the signal strength).
- Updated the presets to take advantage of the improved processing. Also created a few new presets that sound a lot like already present presets, but use far less processing power.

hello hans , thank you for your work

But , i have problem with 3.40beta winamp version and standalone version.The sound cracks and pops all the time. I have noticed than it's only on high quality mode. My system is windows xp sp3 with a pentium dual core 1.8 ghz .

May be for the standalone version , problems with buffer.

Best regards

Garfield

Then your PC is probably not fast enough to handle HQ mode with this version (especially the Loudness "++" option uses a lot of CPU power).

The quality difference between High and Normal quality is very low, so you can just use Normal quality.

hans=> Not fast enough !!! oua !

What processor for this version i need ?

My proccessor run perfect with breakaway fm (http://www.claessonedwards.com/forum/vi ... ?f=5&t=149) who consumes lot of cpu .

It's very strange because , i haven't problem with 3.30 version however with high quality mode and loudness++, may be your software(last version of stereo tool 3.40 beta) is not optimized

Best regards

Garfield

The difference in audio quality between Normal and High quality mode is very very small. So it shouldn't be a problem to use Normal quality mode.

In High Quality mode, I have not made any compromises to the sound quality. In Normal quality mode, I've made some compromises - but such that there is very little difference in sound quality. In Low Quality mode, the sound quality suffers a lot.

Note: Especially the Loudness ++ setting consumes a lot of CPU power. ++ gives a volume boost of about 3 dB, which is considerable. However, when ++ is turned off you might be able to set the Loudness slider a bit highes to gain back 1 or 2 dB. But IMO, Normal quality with ++ on sounds better than High quality with ++ off and a higher Loudness value. (Note: This is caused mainly by the handling of loud high frequencies. I probably need to filter them out before entering the Loudness filter. After doing that, you should be able to reach higher volumes both with and without the ++ setting.)

Edit: I just performed another measurement, and the ++ setting uses almost the same amount of processing power as all the other filters combined (including the Loudness without ++). Without ++ at quality Normal the CPU usage of Stereo Tool and BFM does not differ much. I'll add a filter for loud high frequencies so you can also reach higher volumes without using ++. (Currently I'm using the Final Pre Limiter for that, but it turns out to be not strong enough).

To get back on the previous post: I've done a few quick measurements with a filter that lowers the high frequencies when needed, and the result sounds clearly better (on top of that, I can move the Loudness slider up further and reach an even higher output volume). I'm working on another project right now, but I'll get back to this in a while and try to further improve the result.

I also have a few ideas to improve the CPU load (I can probably use a mix of Low and Normal/High quality processing without loosing any quality - that should give a huge performance boost and also reduce the latency).

Please keep an eye on this thread - I'll post here when I've finished any of the steps that I mentioned here.

The previous (3.30 and earlier) Loudness filter took months to develop, optimize and tweak. This is the first version that includes the new Loudness filter. It is already a lot better than the old filter, but I expect more improvements (performance and quality) to be possible.

Small update: I've changed a few numbers in the processing a bit. Now high frequencies are handled better, and if there are a lot of high frequencies present the result sounds warmer.

(Re-)download the beta version from the download page if you want to have the updated version.

Looking and sounding MUCH better, Hans!

Fake Stereo doesn't work.
I don't use it ... but someone might.

Here's another update (another number changed) - highs now sound clearer and brighter. (Previous versions could sometimes sound like low bitrate MP3s if there was a lot of high frequency content, that has been reduced greatly in this new version).

If your PC cannot handle the Loudness ++ setting, you should now be able to increase the Loudness slider higher than in previous versions to reach higher volumes without using ++. (Note: High Loudness values in combination with ++ still sound bad - albeit a bit less bad than before).

Minor update: Short peaks sometimes got "spread around" in time. That has been reduced a lot. As a side effect, any distortion is also decreased a bit. (And now I know how to reduce it a bit more... Will do that later)

Also, the Low Quality processing now uses the same settings that the normal quality processing uses - which results in a better sound quality when Quality is set to Low (it's still a lot worse than Normal or High quality).