Can Dirac make things worst ?

[DonH56]

That advice is completely counter to everything I have read and understand from a technical viewpoint about virtually any room correction program and also counter to what works best for me whether I have used and measured Audyssey, Dirac Live, or MCACC (have YPAO but have not measured it). The technical leads of those programs, independent researchers such as Geddes, Toole, and Welti, and numerous others also agree. But as you say to each his own.

 

[Krunok]

You have to apply the same phase correction to both speakers.
Trying to have the same phase curve for both speakers, then trying to apply different corrections, will leave you with a weird soundstage. If you like "live" recordings, then you'll feel like all your CDs sound like live recordings and you'll be happy. But forget how the recorded music was intended to be played.

Even for frequency response I wouln't apply different corrections to speakers. At my place, I do it under 100 Hz though, (high-pass filter) because one speaker is in a corner, which gives a +10dB boost in that area. Under 100Hz, you don't know where the music comes from so it is ok. Don't do it elsewhere or you'll have a weird soundstage, with singers singing sometimes in front, sometimes on the left, sometimes on the right. You have to deal with the fact that you are listening in a room, and that it is normal to have some asymmetry.
Correcting the 100Hz-500Hz area by filling the gaps, which are due to measuring errors, could make things better somewhere in the room (I doubt it) but worse 30cm away. It's a no.


As for Pappyblue: Dirac seems to act wisely on the magnitude curve beyond 300Hz, but what it does under 300Hz looks complete bullshit to me. I would desactivate it in that area.
Put a FIR High-pass LR24dB/octave at 40hz instead, and you're done.

Ok, I'll try to summarise your ideas here:

- I would use DIrac on only one speaker, from 1m or so (not listening position) and report the same corrections to the other.
- I wouldn't use DIrac correction under 500Hz.
- I wouln't apply different corrections to speakers.
- Trying to have the same phase curve for both speakers, then trying to apply different corrections, will leave you with a weird soundstage.
- Dirac seems to act wisely on the magnitude curve beyond 300Hz, but what it does under 300Hz looks complete bullshit to me.

In my opinion you are wrong on each and every one of them and I'm really wondering from which sources you've been collectiong information about room EQ. Anyway, as you don't seem like a person who is willing to rethink his ideas and consider other people arguments I really see no point in repeating the same things twice.

 

[daftcombo]

Dirac, Audyssey, etc. look magical, and the guys who sell them won't say the contrary.
But they do nothing you couldn't do for free & quite easily with REW and RePhase.
Actually, they do worse. The first post of this thread, by Pappyblue, is a proof that magic doesn't work.
The answer to the question of this thread title is: yes.

 

[Krunok]

Dirac, Audyssey, etc. look magical, and the guys who sell them won't say the contrary.
But they do nothing you couldn't do for free & quite easily with REW and RePhase.

While that is so, it certainly isn't "quite easy". IMHO it would take a person with considerable knowledge about room EQ and loudspeakers in general to do that. Judging by your posts you don't have such knowledge.

 

[daftcombo]

Well IMHO room correction simply doesn't work, except for removing some low frequencies and adding a room curve, things easy to do with REW & RePhase.
Phase correction is also a good thing, and it is also easy to do with REW & RePhase.

 

[DonH56]

My wife and most folk I know would disagree on the ease of achieving the same results using REW and ancillary SW...

BTW, you say room correction doesn't work, then go on to say you do room correction with REW and RePhase...

 

[daftcombo]

Do you know the signification of "except"?

Phase correction is speaker correction, not room correction by the way.

 

[Krunok]

BTW, you say room correction doesn't work, then go on to say you do room correction with REW and RePhase...

Agree. And either he shows some results with it or it's about time to STFU.

 

[daftcombo]

Man, I already stopped contributing to your thread. Let the creator of this one judge who is allowed to give advice and who isn't.

Anyway, I don't see how showing curves would give you an idea of how music sounds in my living room. But you're invited to come and have a listen anytime you want, provided you stop being rude first.

 

[daftcombo]

My wife and most folk I know would disagree on the ease of achieving the same results using REW and ancillary SW...

I can imagine them launching the Dirac Black Box each time they move the furniture.

 

[Absolute]

Must be possible to discuss differences in opinion without being condescending, people

I use the pc version of Dirac and use manual eq or REW auto eq with the minidsp 4x10hd when playing other sources. Dirac makes the sound warmer and separates details better, manual or REW auto eq (limited eq points) sounds more dynamic or unrestrained, somehow.
It could be due to frequency response differences, so I will look into it and post my finding and graphs in due time.

I really don't think we should laugh away first hand experiences without further investigations, so is it possible that the preference for no Dirac under 300 hz is a result of a feeling of a lack of capacity and power due to drier sound and/or suck-outs? I can imagine capacity to become a problem with small speakers after Dirac due to removal of alot of free gain.

 

[Krunok]

Must be possible to discuss differences in opinion without being condescending, people

I use the pc version of Dirac and use manual eq or REW auto eq with the minidsp 4x10hd when playing other sources. Dirac makes the sound warmer and separates details better, manual or REW auto eq (limited eq points) sounds more dynamic or unrestrained, somehow.
It could be due to frequency response differences, so I will look into it and post my finding and graphs in due time.

I really don't think we should laugh away first hand experiences without further investigations, so is it possible that the preference for no Dirac under 300 hz is a result of a feeling of a lack of capacity and power due to drier sound and/or suck-outs? I can imagine capacity to become a problem with small speakers after Dirac due to removal of alot of free gain.

It is not about Dirac - applying room EQ only above 300Hz makes no sense at all because, as I already stated, room is affecting the sound significantly only up to Schroeder (transient) frequency, and that is usually 250-300Hz. If you don't want to apply room EQ in the 20-300Hz range than you don't need to apply it at all. And that is not a matter of personal opinion but rather a fact which can easilly be checked.

Btw, your impressions about differences between Dirac and REW EQ are hardly valid proof until they are verified with blind test.

 

[DonH56]

I can imagine them launching the Dirac Black Box each time they move the furniture.

No worse than running Audyssey though you do have to connect to the PC. Imagine teaching her to run REW. I like REW but would not consider it a push-button solution to room correction.

 

[RayDunzl]

Phase correction is speaker correction, not room correction by the way.

I believe the phase of the sound leaving my speakers to be well matched.

The cancellation occurs (I think) because my room is not rectangular at the rear. One speaker hits the back wall at 18 feet, the other, at 27 feet, the null is in the reflection, so, there is some room for experimentation with a small range of the bass here, where the room (not the speakers) is causing a null.

I'm thinking my first "move the subs around" experiment will be to create a bass sink at the rear of the room, a little delay and antiphase there might work, I'll find out. It's not something the automation will create for me.

 

[daftcombo]

It is not about Dirac - applying room EQ only above 300Hz makes no sense at all because, as I already stated, room is affecting the sound significantly only up to Schroeder (transient) frequency, and that is usually 250-300Hz. If you don't want to apply room EQ in the 20-300Hz range than you don't need to apply it at all. And that is not a matter of personal opinion but rather a fact which can easilly be checked.

I understand that you want to correct the low frequency reponse because of room modes. But when you move the mic around, the peaks & dips change. An average (as Dirac does) will give you better sound here, worse there. "Here" can mean your right ear, "there" your left one. Or "here" your seat, "there" your friend's.

Over 300Hz, you can control the slowly descending curve to compensate wall reflections. If you are in a well treated room or a studio, you should aim at an horizontal. Movie theaters curves start far beyond 300Hz, and are also "room correction".

 

[daftcombo]

I believe the phase of the sound leaving my speakers to be well matched.

The cancellation occurs (I think) because my room is not rectangular at the rear. One speaker hits the back wall at 18 feet, the other, at 27 feet, the null is in the reflection, so, there is some room for experimentation with a small range of the bass here, where the room (not the speakers) is causing a null.

I'm thinking my first "move the subs around" experiment will be to create a bass sink at the rear of the room, a little delay and antiphase there might work, I'll find out. It's not something the automation will create for me.

IMHO, in a weird room, you will have a weird soundstage, whatever correction you apply.

 

[Krunok]

I believe the phase of the sound leaving my speakers to be well matched.

The cancellation occurs (I think) because my room is not rectangular at the rear. One speaker hits the back wall at 18 feet, the other, at 27 feet, the null is in the reflection, so, there is some room for experimentation with a small range of the bass here, where the room (not the speakers) is causing a null.

I'm thinking my first "move the subs around" experiment will be to create a bass sink at the rear of the room, a little delay and antiphase there might work, I'll find out. It's not something the automation will create for me.

I agree. I believe if our speakers would be measured in anechoic conditions they would produce matched phase response. What I found interesting is that only phase mismatch at 83Hz caused dip in both speakers response but mismatch at 350Hz didn't cause anything. Could it be that lower frequencies are more prone to cancelation due to phase mismatch?

 

[daftcombo]

It is because your speakers are in phase. Those measurements aren't precise, sometimes they take into account reflections sometimes not, that's why you think you see bumps & dips. By the way, at LP you get both the direct waves and the reflected waves. The wall wouldn't affect the phase of the direct waves, would it? So if you "correct" (actually : deteriorate) the phase of one of the speakers, the direct waves won't be in phase anymore.

The dip at 83Hz is caused either by a measurement error, or a room mode.

You should not worry about all that if you have a good sound in the first place.

 

[Krunok]

It is because your speakers are in phase. Those measurements aren't precise, sometimes they take into account reflections sometimes not, that's why you think you see bumps & dips. By the way, at LP you get both the direct waves and the reflected waves. The wall wouldn't affect the phase of the direct waves, would it? So if you "correct" (actually : deteriorate) the phase of one of the speakers, the direct waves won't be in phase anymore.

The dip at 83Hz is caused either by a measurement error, or a room mode.

You should not worry about all that if you have a good sound in the first place.

Not so - this is both speakers response before (green) and after (blue) I adjusted phase of left speaker to the phase of the right speaker:

 

[daftcombo]

Yes, if you change the phase on one speaker, the frequency response changes too. Is it better?
Any difference in sound?