More advanced EQ - (Adjustable 10 Band, Pre-Amp ++)

[Inocybe]

I think a good equalizer is one of the most important things in a music player, either to adjust the sound to be more natural (flat), or customized. A 5 band EQ is quite limited, and it's very hard to get the sound close to right, even if the bands are adjustable and/or with band widening.

Another thing is an adjustable EQ Pre-Amp (sound level before reaching the EQ). Like your Pre-cut. This is very important to prevent digital clipping when adjusting the EQ settings. It will also optimize the headroom, by adding gain before the EQ. Here a EQ db meter would be useful (placed after the EQ), with "0" marked as clipping.

Here is what I would like to see/have:

1. 10 band EQ.

2. Each band adjustable

3. Each band with possability to be widened

4. EQ Pre-Amp/Pre-Cut (to prevent digital clipping)

5. EQ db Meter (Headroom/Clipping)

To go really nuts, here is something I have wished for for a long time, and something that, as far as I know of, don't excist anywhere:

6. Store EQ settings per folder (album)

This could be just a little text (.txt) file containing the EQ settings (and other settings, like gaps). Before playing songs in the folders, Rockbox would automatically search in this text file, and change the settings (or choose standard settings if no info is found. Why do this? A lot of recordings sound completely different, not only due to the mixers and the mastering process, but also due to the time it was released/made. Personally, I find myself changing the EQ settings all the time, so a feature like this would be very helpful.

[Llorean]

1. Each band increases the CPU load. On many of the players 5 bands is a strain already.
2. This is already the case.
3. This is already the case.
4. EQ Pre-amp creates clipping. In what situation do you expect it to prevent clipping?
5. The gain is measured in db already. Could you be more precise as to what you see this "meter" doing besides just reporting to you what the gain applied is again?
6. If the song is mastered "wrong", why don't you apply EQ settings before you compress it. Generally the Rockbox EQ is intended to offset hardware differences. The less EQ work that is done the better, for battery life, so if you have songs that should always be equalized, rather than ones that only need it with one set of earphones but not your speakers, or what not, you should do so while compressing them to improve performance. This would also not only allow per-album equalizing but per-song, and independent of the software or hardware you use to play them back.

[Inocybe]

Llorean,

1. What about the other players? I see there is differences between versions allready.

2. and 3. I did actually know (should have mentioned that). I was just describing the whole setup.

4. By having minus values, or having a scale of 1 to 100, and default is 50, for example.

5. This live meter would just report db, nothing else. See answer 2. and 3. (sorry).

6. Have tried it, but found it unpractical. This would create a lot of work, creating different versions of mp3's and flacs, depending on where they would be used. I use different EQ settings for my mp3-player and my laptop, for example. I can't see how EQ-settings per folder would create more strain on the CPU, it just replaces the default ones (not in addition). Thanks for suggestions, though

To save CPU load and battery life, these advanced EQ-options could be optional (for those players that can handle it).

[Llorean]

1) It's possible to have it on all players (since disabled bands don't do anything)  but most frequency response curves don't really need more points than we already offer.

4) Please describe further. That statement on its own doesn't clarify anything.

5) So basically, it'd repeat what you already know from actually setting the values?

6) If the problem is with the file, why do you need different EQ files for different players? You fix each song to an individual EQ for that file, then you set _one_ EQ file for your MP3 player that you use all the time to counterbalance the hardware. This solves your situation, doesn't require you to have multiple copies of each song, and doesn't require complicated (and breakable) features in Rockbox.

[Inocybe]

Llorian,

4. When using minus values, it would work like your Pre-Cut. Reducing the gain before entering the EQ. Same as in the MediaMonkey player (Pre-Amp and 10-band, but no db meter).

5. In a way yes, the db result after EQ settings. You could, for example, set how much headroom you would like to have in reserve in case of sudden peaks. Or, this is a bad one, adding gain and accepting some clipping to get high sound levels. This by observing the db meter and adjusting the Pre-Amp (Pre-Cut).

6. My mp3-players sound differently, so do my laptop, desktop and mac, and not the least, my home stereo (all in flat EQ position). But, this is a feature that is not THAT important. A 10-band EQ would make me happy for some time

[Llorean]

4) So why isn't our pre-cut enough? I asked for situations where pre-AMP reduces clipping, as we already have pre-cut...

5) What values do you expect to use for this? All you know is the EQ gain. So if the highest EQ band is 5db and there's no precut, the meter will say "5db".

6) I already addressed the fact that the hardware sounds different. You have one EQ file on each to account for the hardware differences, and you equalize the tracks directly to account for the mastering differences. You responded to this by repeating the conditions you gave last time, which I already answered.

Please, read what I'm saying carefully. At this point it's beginning to look like you aren't understanding what I'm asking. If that's the case, tell me where I've been confusing and I'll clarify.

[isanggon]

Inocybe,,

I think 2,3,4,5 is aready exist(functions fully) on rockbox. Please read rockbox manual carefully.

And you can easily modify rockbox source to support 10band or more band eq, but there are hardware limit because device's prossor hasn't enough power to support it. Ipod hardly support 8band, overclocked h100 series hardly support 10band. Only gigabeat series can support 10band or more band eq(at least gigabeat s can support 22band eq or more).

[Llorean]

isanggon - read what he's requested. We have no pre-amp for the equalizer. We have no per-track or per-folder equalization. We have no separate db meter (whatever that's supposed to be). He's already been told 2 and 3 exist. Please read the whole thread before responding, and carefully, to avoid adding additional confusion to what is already apparently a confusing state.

[Inocybe]

4. "Pre-Amp" is just the word for the feature, just like how MediaMonkey uses it. The FEATURE can ADD gain and REDUCE gain. Of cource, by adding gain, you don't reduce the chance of clipping. Adding gain is also useful, as I have mentioned.  MediaMonkey example: 0 db is default, and you can add or detract up to 20 db's (-20 to 20 db).

5. Can't you measure the db's live? This will give the actual db result. Will strain the CPU a little, I guess.

6. Sorry for repeating myself. I see your point. Unfortunately, many songs are allready compressed or Flack'ed. Would take foreer to do it again. But again, this isn't a big thing.

Misunderstanding is possible, even after reading carfully (it' human) BTW, I don't think my explanation was so bad (like point 1, 4 and 5).

[Llorean]

4) you haven't said how adding positive gain is useful. We already have a volume control for making things louder. Why, exactly, do you need add gain, and not just cut it?

5) It can change from fraction of a second to fraction of a second, and won't give you any clue as to what's coming up, or what the next song will be like. Measuring it live is nearly useless.

6) Remember, new functionality makes the binary size larger, the code more complex, and can even reduce battery life slightly for people not using it. If it's something that can be fixed by doing a process _once_ to your music, that's generally a better alternative than trying to code a complex solution into Rockbox. Especially since the alternative solution solves it for you everywhere, rather than requiring you to make feature requests to people working on every other music software you use.

[Inocybe]

4. I have: "It will also optimize the headroom, by adding gain before the EQ.". Normally, in an digital EQ, there is headroom to spare. This to have room for EQ settings. If EQ is flat, or especially if you reduce lower frequences, you could add Pre-Amp gain in many cases. This is not the same as using the master volume. Optimizing headroom will create better sound quality. The goal is to get as close to 0 db as possible, but without clipping. It will also play louder. This is why many new records are mastered higher than the clipping level, to get it as loud as possible (bad practise). The master volume (Rockbox) is then controlling this sound level.

5. That is the point of a live db meter. Often they show the peaks longer so it's easier to follow. And yes, it would be different from song to song. But, it would show you the headroom in a clear way. for example, if most (all of the songs) is way below the 0 db limit, you could add som gain and still see that there is some room left. Or, if 90% of the songs is way below the clipping point and 10% really peaks, you could add some gain so that the 10% have clipping issues, but the rest of the songs will have higher volume. If it was useless, why would 99% of all professional sequencers have it? No, it's far from useless if it's used coreectly.

6. Understand what you are saying

isanggon,

What I understand is that some players have two CPU's (one audio and one video). Rockbox can only use the smaller one, and therefore there could be some performance problems. Those players with only one CPU (like some iPods), seem to perform better with Rockbox. Please correct me if I'm wrong. I have read the video performance chart.

[soap]

Only the iPod Video has a dedicated video decoder.  Outside that all the iPods (and sansas) have (basically) the same CPU (a dual-core ARM7).
The differences you see in video decoding performance is mostly inversely proportional to screen size - less pixels to decode = faster speed.

[Febs]

How is #5 different from the existing peak meter?

[Inocybe]

How is #5 different from the existing peak meter?

Please note that I don't know the inner workings of Rockbox. If the peak meter can be placed in the EQ window (customized), then it propably would be the same. The thing is that it's very useful when adjusting the EQ. On the other hand, Rockbox has many other ways of adjusting the sound, and this would also effect the db output. So, just placing the peak meter after the EQ, may not be enough. The best thing would be to have it in every "effect" window (including a preamp adjuster).

[Febs]

Thanks, but you did not actually answer my question.