Does digital room correction and equalization make all speakers sound the same?

[Fitzcaraldo215]

1 minute ago, Audiophile Neuroscience said:

 

Yeh, just to clarify, it was the OP who asked Does digital room correction and equalization make all speakers sound the same?

 

"The amount of reflected sound" is also interesting. Paraphrasing Barry Diament DRC is an an amplitude  alteration at the speaker for a time domain problem of ringing in the room caused by the physical properties of the room. It doesnt change the Q of the room and reflections and resonances continue in time, less energized. I may not have accurately represented this viewpoint as I am not an engineer.

What I was getting at was more the fact that you pay good money for high-end speakers and the hack them with DSP to alter the sound. From a perceptual point of view it has to mess with the contribution of direct sound heard from the speakers, notwithstanding Haas/precedence effect or anything else.

 

 

Ok, DSP Room EQ changes the direct sound of the speakers. But, if the sound of those precious speakers from where you sit in your room is not improved to your own ears by DSP EQ in comparative trials, then don't use it.  It is easy to see with speakers in this report or in your own room in calibrating DSP EQ that the sound has been measurably improved.  But, judge for yourself.

 

Direct sound is only one of many complex components of the sound field we hear in a room, whether you audition speakers at a dealership or at home.  So, worrying about just direct sound will obscure the total perceived sound, consisting of direct plus reflected sound in the room.

[Fitzcaraldo215]

16 minutes ago, Audiophile Neuroscience said:

 

I mostly agree. I certainly agree that if you hear an improvement that is what matters. I have heard DRC a number of times and like Barry, I hear different not necessarily an improvement. I hear an improvement with room correction with acoustic treatments. It intuitively makes sense that if the room is the problem, treat the root cause and leave that lovely direct sound alone. That is not practical or desirable in many if not most cases, I get that.

 

Beyond any of the above, there are those in this forum that maintain room correction or treatment is superfluous to the quality of the playback chain. I don't agree but it does argue against distorting the speaker direct sound (or anything else in the playback chain).My approach is to strive for the best undistorted playback chain *and* best room, as an ideal anyway.

First, having measured and corrected a number of rooms myself, if you believe that correcting narrow band modal swings in the bass of +-10 or 20 dB is not an improvement, then what can I say?  Yet, that is typical.  I get the impression that the esteemed Barry was not measuring,  but "trusting his ears".  

 

Frankly, there is no point in doing anything if you do not measure.  That is automatic with DSP EQ, such as Dirac. If you are averse to measurements, do not waste your time on DSP EQ or even passive treatments.  You will just be kidding yourself.

 

I know people always talk about passive room treatments. But, I strongly advise against treatments.  If you look into it seriously, it is way more complicated than sellers of such stuff will tell you.  Bass traps, etc. need to be huge to control the bass modal issues where the big room distortions occur.  It is not physically possible with off the shelf bass traps, etc.  They are just not big enough and do not go deep enough.  You really need to know what you are doing.  And, measurements are just as important as for DSP.  Without measurements, you may be fooling yourself.

 

The best way to get your feet wet on room correction is to do a free trial of Dirac.  I have used it for years, and I would never be without it.

 

 

 

[Fitzcaraldo215]

3 minutes ago, Audiophile Neuroscience said:

 

I agree that to treat bass you need proper traps, not off the shelf bits of foam that only work in the HF. Acoustics is a science and people like Art Noxon (engineer and physicist) and others are aware of such things.They are also aware where nodes and anti-nodes will be in the room based on scientific principles. Measuring them is fine if you want to but not really necessary for physical treatments. You know resonances are in corners, half and quarter lengths along walls for harmonics and so fourth. You know where first reelections are and depending on what amount of absorption you need, you need to know measurements of the absorptive material.Still, there is nothing stopping you from measuring and confirming that the bass trap is indeed best placed in the corner and is indeed of adequate size for the lowest fundamental frequency of resonance.

 

For me as said , I like to hear the unadulterated direct response of my speakers, even more obvious when you treat the room and hear less of the unwanted room contribution.Sure some room contribution is fine but for me, late reflections etc.

 

Another cool thing with large bass traps throughout the room is that half the cylinder is foil faced and half not. Changing the sound of the room is possible by merely rotating the cylinders. It is quite amazing.

 

Its just another one of those areas that audiophiles will have a strong preference for, one way or another. Different strokes.

Well, suit yourself.  I, myself, am much more convinced by Floyd Toole than Art Noxon. Toole is, first, principally reliant on measurements, then minor fine tuning by ear.  And, second, he is not a big fan of passive treatments, preferring careful speaker and listener positioning and EQ, especially in the bass below the "transition frequency" where the room dominates, but also full range.  Absorption and diffusion are certainly able to change the sound, but Toole finds them vastly overrated.

 

I highly recommend Toole's Sound Reproduction - 3rd Edition, released this past August.  It gets technical in some areas, as is inevitable due to the complexity of the science of speaker/room acoustics. But, he is a terrific writer, and much that he has to say is quite clear, even to a layman like me.  I think you will find his understanding of the issues rather different in key areas than Noxon's or your own.

 

As to bass traps, I think you will find that they are measurably relatively ineffective below 100 Hz, even very expensive ASCs, unless custom designed to be really huge and intrusive.  And, yet, this is where room modal swings are the biggest influence in messing up the sound of even great speakers in typical rooms.  DSP EQ is preferred by Toole and also many acoustics professionals.  I think we can easily see why in the measured graphs early in this thread.

 

 

 

 

[Fitzcaraldo215]

5 hours ago, firedog said:

I've used DSP and treatments in the same environment. Both work, albeit somewhat different results. 

Corner bass traps made a huge positive difference in my environment. 

Small room, I sit against the back wall. With no treatments and no DSP, I get echo back to my ears from the back wall. With absorbers behind me on the back wall I don't. Sounds much better than without. 

Makes sense to me.  Bass traps affect the sound, and if properly employed, they can do positive things, but not necessarily over the full required frequency range unless they are huge.

 

Back wall absorption in your case might be a very good thing.  Although, some might agree or some might say diffusion is better.  Personally, I avoid sitting against the back wall and I use no treatments back there.

[Fitzcaraldo215]

8 minutes ago, User471 said:

A question if I may about implementing room correction and active crossovers in DSP?

 

I have tried Dirac, professional gear (dbX) and 'high end' boxes (Illusonic) to do both room correction and speaker crossovers for my active hybrids (Sanders Model 10, think Martin Logans). In each case the DRC/crossover DSP came after the primary DAC in my system and I was, on the whole, happier with it on rather than off

 

And then it dawned on me - if I am doing DA conversion in my ridiculously expensive DAC, and then feeding the analog signal through a second ADC/DSP/DAC process between preamp and power amps, then am I not simply listening to the DAC in my crossover, not the primary DAC? And in that case it seems it would make no difference what DAC or other analog source I used, it would all still sound very much the same as a result of the (presumably much lower spec) DAC in the crossover?

 

Have I got some fundamental point of crossover/DRC design wrong here? 

 

I'd be interested to hear some technically informed opinions

Your thinking is on the right track, I believe.  I know many claim that a particular a-d or d-a is audibly "transparent" to them.  And, yes, DSP room correction, bass management, etc.are terrific.  But, I do not consider a signal path with cascaded d to a, a to d and d to a to be optimal or as potentialy "transparent".  Noise and distortion are cumulative through the signal path.   I firmly believe that using just one final d to a conversion after DSP, etc. is best.

 

I do embrace minimalism in the audio signal path, with extraneous components eliminated where ever possible.  I personally use a PC as the only source in my 7.1 system.  JRiver provides the library, player and system control functions, together with its bass management plus the Dirac Live VST plugin.  Output is via USB to my Exasound e28 DAC, then to my amps, sub and speakers.  I use it for audio music - mainly Mch SACD/DSF rips converted on-the-fly to PCM at 176k/24 bit - and video from BD and TV via HDMI to my monitor.  

 

I cannot begin to describe how happy I have been with this setup for many years.  It provides easily the best sound of my lifetime.  Extra conversions to/from the digital and analog domains could not possibly sound better or more faithful to the original source.

[Fitzcaraldo215]

Kal and I are multichannel guys, so we both do the xovers prior to the Mch DAC.  If you have a stereo DAC, then you are limited to doing it after the DAC, since you do not have the 3 DAC channels necessary for 2.1. 

 

Don't know about your sub, but possibly you can send post-2.0 DAC analog line or speaker level input to it while the main channels get full range signal in parallel.  This is not a true xover situation, though.  It involves just a low pass filter in the sub.  Not ideal, but perhaps better than nothing.  REL likes that arrangement for their subs, but I don't.  However, it does not revert to the cascaded d-a-d-a chain for the main channels.  I also do not know how well that gets along with DSP EQ like Dirac.

 

A miniDSP unit could do it for you in place of your current DAC, but is that too much a compromise?  A few expensive analog true crossovers exist - Wilson, for example - but I think you would be better off with a Mch DAC, doing the xovers in software.

 

 

 

 

[Fitzcaraldo215]

4 minutes ago, HardrockInMiniMac said:

Oh boy, what a question:

 

Digital room correction and "equalization" are two totally different things. 

 

Does gasoline make all cars the same? Does bodybuilding make all people the same? Does war make all people the same?

 

1. LS do not care about what you do with a signal, they just reproduce what they receive

2. Room correction as it says corrects the room not the speaker

I am afraid it is more complicated than that.  In simple terms, so called "room correction" operates by altering frequency response in the signal chain ahead of the speakers and room, so it changes what comes out of the speaker.  Ideally, that corrects measurably the response in the room and heard by us in a way complementary to the frequency non-linearities due to the room. It is perfectly legitimate to call that equalization, though it is directed primarily at correcting room behavior.  Applying calculated, calibrated frequency domain filters to the signal, as room correction does, is equalization.

 

But, if the speaker, or less likely, amps or electronics are altering frequency response vs. the target curve, then that will get corrected, too.  The mic during calibration does not know whether the room or something else caused a deviation from target curve response. 

 

Some room EQ also attempts to correct timing or impulse response as well as frequency response, again by altering what comes out of the speakers.

 

So, room correction can't just correct the room.  The room is passive.  It can only correct what the calibration mic hears, which, ideally, is a perfectly linear speaker and sound system in a room that is the only thing corrupting that perfect linearity,  If so, then, yes, it corrects only for the room by altering the sound that comes out of the speaker.  But, in the real world it is EQing for any and all non-linearities, not perfectly, but, hopefully, making the sound better.

 

I think room EQ also does a good job in Mch systems of more closely voicing the frequency response between channels, either when dissimilar speakers are used or when the positions of identical speakers cause frequency response differences. It helps achieve better sonic integration. This has its limits, however.