What is the point of linear phase . . .

[djanthonyw]

Yes, I understand what the actual point of linear phase is. However, any analog EQ, even the highest end analog mastering EQ is not linear phase.

If someone prefers the sound of what analog does, and even the highest end EQs are not linear phase, then what is really the point of using linear phase aside from adding unnecessary latency?

[DJErmac]

If you're using two layers for the same sound, for example if you're using one bass filtered layer and a top filtered layer, you WILL want linear phase.

Anything else will change the phase, meaning that the global sound will drastically change everytime you tweak anything on a layer. Using linear phase, you'll simply be changing whatever you want, global sound staying exactly like before.

This is exactly what happens with linear phase multiband processor such as compressors. The linear phase ones ensure a sound nearly the same from the one you had at start. The other ones will add phase issues and change the global sound from scratch, even if it's barely noticable sometimes.

Linear phase becomes a thing when you have several sounds that need to stay 100% coherent together.

In other words : do whatever you want as long as you're not hearing any problem you can't solve. Linear phase is technically needed when phase issues appear.

[plexuss]

One reason to use linear phase EQ is when you dont want phase colouration. Also, as stated, to avoid phase issues when otherwise using an EQ that affects phase, Analogue gear is great but it has its problems. Digital gear is great buit it has its problems. The crux is using the right tool for the right job.

[jtsterays]

Linear phase is not possible in analog. And it's just another tool at the end of the day. Some example where linear phase might be useful :

- Layering drums : If you layer with the frequency split method (e.g kick 1 lowpassed, kick 2 highpass etc...). Changing the filters to linear phase will drastically change the end result. Same for multitrack drums.

- Multiband crossover : Minimum phase crossover might result in tonal change depending on the implementation, you might hear holes at the crossover points. linear phase avoids this (but will introduce ringing if slope is too steep).

- Clean stereo image : If you're doing mid side or left right EQ, linear phase will avoid the blurring of the stereo image.
Try hard pan a sound to 1 side, then add a highpass to the sidechannel at ~100hz, pan must be before highpass. You should hear the sound widen up (wider with steeper slopes), big difference. Since a lot of people usually put the same sidechannel highpass on the master, this results in every panned sounds (not just hard panned) getting the same widen effect which loses localization, stereo image will be "blurry", not always a desired effect. The solution is to change the highpass to linear phase. Applies to L/R EQ too.

- Waveform peaks : EQing with minimum phase add peaks to the waveform, more deformed with extreme filters. This alone won't do any harm to your audio, but might cause problems if you have non linear processors after that (compressors, saturators, etc). Let's say you have a master chain like this : Comp > Clipper > Limiter. You have carefully optimized everything so they react exactly how you wanted without clipping or pumping. But you realized you need to EQ, so you add it before everything then tweak, but because minimum phase EQ add peaks, this will now cause a butterfly effect to the rest of the chain because the waveform is changed which might reintroduce the clipping and pumping that you have carefully set to avoid. Linear phase makes sure the waveform is unchanged.

[djanthonyw]

Yea, that is my point though. The highest end analog mixing and mastering equipment isn’t even linear phase, so why do people make such a big deal about it, especially when many people prefer analog sound.

[DJErmac]

I have the feeling that you are understanding "analog" as "superior quality"... Be aware that this can be proven in no way by anybody in the galaxy. This is just a matter of tastes. Standing from this point of view may lead you to false conclusions. Some prefer analog, some prefer digital. And it proves nothing interesting really.

If you are offered a perfect phase control which is linear phase, showing the most faithfull possible sound, why would you refuse it as an option ? Do you prefer losing control on your phase when mixing, and hearing high frequencies ringing, and low frequencies mysteriously disappearing (even flanger sound in the worst possible case of analog gear), which is the typical effect of phase issues ?

Maintaining phase is precious in some cases. When the same sound is playing several times at the same time mainly.

[djanthonyw]

Yes, but linear phase EQs can also be prone to pre-ringing.

[DJErmac]

Then let’s just all forget about phase.

[AGIGA]

Yes, but linear phase EQs can also be prone to pre-ringing.

If you haven't watched the video "EQ: Linear Phase vs Minimum Phase" from Dan Worrall yet, here is the link:

[kraster]

Yes, but linear phase EQs can also be prone to pre-ringing.

Well then it's a case of choose your poison.

Phase shifting due to non linear phase or a chance of pre ringing artifacts.

Pre-ringing is more noticeable on low end stuff and can effect transients.

Phase shift can become problematic when you have two sources that are phase related and will manifest as comb filtering.

Choosing the best tool for the job is the takeaway here than just choosing one over the other as a blind preference.

[DJErmac]

In a few words : when you need phase alignment (multi-mic recordings/layering...), you choose linear phase, when you don't care, you do whatever you want with the tools you want.

[vurt]

The highest end analog mixing and mastering equipment isn’t even analog,

whut?

[plexuss]

The highest end analog mixing and mastering equipment isn’t even analog,

whut?

I know. I wasn't going to say anything and chalked it up to legalized cannabis.

[djanthonyw]

The highest end analog mixing and mastering equipment isn’t even *linear phase.

[Igro]

The highest end hardware synths could only dream of what the latest digital synths can do. And with all those possibilities the linear phase EQ is very handy. New techs, new problems, new solutions.