2CH Room Correction Processors vs MCH

[Trell]

Auto Room EQ does absolutely nothing for me and many other people. All Auto Room EQ suck to me.

So this only pertains to people who feel that Auto EQ does something good for them.

As for ceiling speakers, Atmos sounds so cool in my room, can’t speak for anyone else. If they don’t sound cool to you, then it’s understandable you don’t want them.

Also, I don’t think I’ve seen measurements of Ceiling speakers with and without Auto EQ. But with the type of surround sound effects that come out of all the surround speakers and ceiling speakers, I just don’t see what Auto EQ will do for ambient sounds.

Most of the time, the surrounds and ceilings are just for cool ambient effects. Aircrafts, Thunder, birds, dragons, missiles, things upstairs, etc. They are very cool. But not exactly anywhere near as important as the front speakers and subwoofers.

I'm just pulling your leg

 

[PENG]

Audyssey uses FIR filters, which are not linear phase. I have reason to suspect a lot of the deleterious effects of Audyssey is that is mucking up the careful time alignments inherent in the design of the speakers. Also the room responses are downgraded by Audyssey.

Dirac I have no experience of, however Dirac uses IIR filters which have a far superior phase response.

Since I have designed all my speakers, I am able to tweak them as desired.

So I do not like Audyssey at all, and suspect many of you, if not all, would be better off without it.

On what you said about IIR and FIR filters, I suggest you research the topic more thoroughly and may be make a correction (that would be nice since you are highly regarded on AH) to avoid readers who may interpret your kind of definitive styled statements incorrectly.

On the topic of FIR vs IIR (obviously the more you search, the more good reads one will find):

FIR vs IIR filtering (minidsp.com)
FIR Filter Properties - dspGuru
on_room_correction.pdf (diracdocs.com) Note: This was written by Dr. Johansson, CEO of Driac Live.

Also, as Wiki summed things up here:
Infinite impulse response - Wikipedia

Advantages and disadvantages

"The main advantage digital IIR filters have over FIR filters is their efficiency in implementation, in order to meet a specification in terms of passband, stopband, ripple, and/or roll-off. Such a set of specifications can be accomplished with a lower order (Q in the above formulae) IIR filter than would be required for an FIR filter meeting the same requirements. If implemented in a signal processor, this implies a correspondingly fewer number of calculations per time step; the computational savings is often of a rather large factor.

On the other hand, FIR filters can be easier to design, for instance, to match a particular frequency response requirement. This is particularly true when the requirement is not one of the usual cases (high-pass, low-pass, notch, etc.) which have been studied and optimized for analog filters. Also FIR filters can be easily made to be linear phase (constant group delay vs frequency)—a property that is not easily met using IIR filters and then only as an approximation (for instance with the Bessel filter). Another issue regarding digital IIR filters is the potential for limit cycle behavior when idle, due to the feedback system in conjunction with quantization."


Whether Audyssey's filters are linear or minim phase, it wouldn't be because it is FIR because it could do either (may be both too I would assume) depending on implementation. As often is the case, there are pros and cons of each, Dirac is smart in claiming the benefits of taking the advantages of both.

I highly recommend those interested in the popular Dirac and Audyssey to read the Audioholics.com interviews in order to get the info directly from Dr. Johhansson (Dirac) and Dr. Kyriakakis (Audyssey founder)

Dirac Room Correction Interview With Mathias Johansson | Audioholics
Audyssey MultEQ Room Correction Interview With Chris Kyriakakis | Audioholics

To quote some of what Dr. Johansson said in interview:

"...Dirac Live uses a proprietary structure that is neither plain FIR nor plain IIR..."

"...Dirac’s solution is to use the best of the FIR filter (mixed-phase correction, i.e. time-domain correction) and IIR’s for what they are best at...."

I have read many articles on the FIR vs IIR topic and from my understanding, again, both have their + and -, but if processing power is not the limiting factor, FIR appeared to be superior overall for REQ applications. Dirac Live's approach to use sort of a hybrid approach does sound convincing and I believe eventually, if not already, they can do a better job than YPAO, AARc, Audyssey. I have read little about Trinnov, but to me if they were the best or not it wouldn't concern me at all because there is no way I would pay the high premium when I am already happy with Audyssey.

 

[Movie2099]

Yeah my daughter and her friends and cousins eat at Taco Bell all the time. No way I’m eating there. If I’m eating fast food Mexican, it’s gotta be at least Taco Bueno.

Where is the White Castle love?

 

[Pogre]

Pretty much what I do is eq my subs and 2 main speakers together. I go for flat then use DEQ and onboard sub tuning to implement a house curve.

I may have misunderstood when I made this reply. I do run room correction for all of my speakers, 5.2. I don't limit anything either. Once I do that then I go back in and dial my subs in, playing sweeps with only mains and subs. I use a combination of the MultEQ app and a MiniDSP 2x4 HD for 2.1 music listening, which is a big chunk of our usage. My wife doesn't even turn the tv on anymore.

I feel that having a smooth fr for music (especially bass) is more critical and more audible if it's not right.

 

[Pogre]

Okay, I dug around a little and found an old sweep In pure direct, to compare with what Audyssey by itself can do for my bass.

That is after running req so the distances and levels were set, but there's no dsp at all. This next one is what Audyssey did by itself.

That's such a huge improvement and you can hear it. This is why I just don't understand the hate for room correction. Which one do you think you would prefer? I know which one of those I prefer. MultEQ is a huge, huge improvement. It straight up sounds dull and anemic in pure direct.

 

[Trell]

Okay, I dug around a little and found an old sweep In pure direct, to compare with what Audyssey by itself can do for my bass.

View attachment 48078

That is after running req so the distances and levels were set, but there's no dsp at all. This next one is what Audyssey did by itself.

View attachment 48079

That's such a huge improvement and you can hear it. This is why I just don't understand the hate for room correction. Which one do you think you would prefer? I know which one of those I prefer. MultEQ is a huge, huge improvement. It straight up sounds dull and anemic in pure direct.

For small rooms some EQ is needed to knock down peaks.

Below is what Genelec GLM AutoCal corrected (it only corrects peaks) in my small office where I sit less than 1m from the speakers. The crossover is set to 95 Hz, and GLM will phase adjust subwoofer with one speaker at the crossover. After calibration I added a HF tilt which is why the blue line slopes down.

The difference is clearly heard, and for the better.

 

[AcuDefTechGuy]

Where is the White Castle love?

White Castle? Is that a fast food Mexican place?

 

[AcuDefTechGuy]

I'm just pulling your leg

Why.....you......

 

[AcuDefTechGuy]

I have read little about Trinnov, but to me if they were the best or not it wouldn't concern me at all because there is no way I would pay the high premium when I am already happy with Audyssey.

Not paying $30K for Trinnov for all 32 speakers?

What if they made a standalone 2CH Trinnov processor for only $1K?

So you wouldn't RECOMMEND a $17,000 Trinnov AVP that measures about the same as a $1,200 Denon X3600?

 

[PENG]

Not paying $30K for Trinnov for all 32 speakers?

Good point, if I do use 32 speakers then yes I would pay if there are no better alternatives.

 

[PENG]

For small rooms some EQ is needed to knock down peaks.

The difference is clearly heard, and for the better.

Clearly heard, okay, but for the better? May be not, ADTG may prefer to keep those peaks. He probably hates REQ because the good ones do remove the peaks in the subwoofer's range.

 

[Pogre]

For small rooms some EQ is needed to knock down peaks.

Below is what Genelec GLM AutoCal corrected (it only corrects peaks) in my small office where I sit less than 1m from the speakers. The crossover is set to 95 Hz, and GLM will phase adjust subwoofer with one speaker at the crossover. After calibration I added a HF tilt which is why the blue line slopes down.

The difference is clearly heard, and for the better.

View attachment 48080

You can certainly see that it looks much better! It's surprising what just knocking the peaks down can do. It makes the dips look far, far less egregious when you flatten out those mountain tops. You have a couple of sweeps that look similar to mine before correction.

 

[Movie2099]

White Castle? Is that a fast food Mexican place?

Haha, no White Castle down in OK?

 

[Pogre]

Haha, no White Castle down in OK?

None close to me (Phoenix) either, tho I seem to remember hearing that they might be here soon...

 

[Movie2099]

None close to me (Phoenix) either, tho I seem to remember hearing that they might be here soon...

Do you have Krystal’s? Almost the same thing.

 

[Pogre]

Do you have Krystal’s? Almost the same thing.

Why, I don't know but I'll take a look after I finish this post. I'll tell ya, I think those frozen boxes of White Castle burgers you can buy at the grocer aren't bad at all. I used to grab a box of 6 for lunch every once in a while and toss 'em in the microwave. I thought they were actually pretty good for what they were. I can only imagine they're better right from the source.

 

[Movie2099]

Why, I don't know but I'll take a look after I finish this post. I'll tell ya, I think those frozen boxes of White Castle burgers you can buy at the grocer aren't bad at all. I used to grab a box of 6 for lunch every once in a while and toss 'em in the microwave. I thought they were actually pretty good for what they were. I can only imagine they're better right from the source.

Oh yes! Haven’t had a crave case in a long time, but damn, taking down 10 or so and some onion rings and some fry’s. Now it’s making me hungry!!

 

[lovinthehd]

Haven't seen a White Castle in over 50 years! Don't miss 'em, tho. Frozen burgers? How lazy can you get?

 

[AcuDefTechGuy]

Clearly heard, okay, but for the better? May be not, ADTG may prefer to keep those peaks. He probably hates REQ because the good ones do remove the peaks in the subwoofer's range.

Yeah I think a little peak here and there doesn’t hurt. I probably like a little peak in both the bass and treble.

It seems REQ makes the sound less “lively” subjectively. And this is the case before I ever did any REW measurements. Apparently I don’t like the sound of a flat FR.

 

[lovinthehd]

I’ve driven by them. But never eaten anything from there. Why? They’re good?

Watch Harold and Kumar Go To White Castle first if you do!