room correction

harley52 · « **on:** 4 Apr 2014, 04:46 am »

Danny and others,
I was reading an article about a Mac room correction system. The guy mentioned that the type of speakers that correction would help the least are Omni directional speakers. Is that right?

Also he spoke of the unit being capable of phase and amplitude correction. Hmmmm. If it can do that then that makes speaker placement a lot less critical. Right? Ok now that I have electricity again I'll send this. One of my poor kitties is NOT having fun tonite/morning.

Thanks

Danny Richie · « **Reply #1 on:** 4 Apr 2014, 02:35 pm »

Room correction above 200Hz doesn't really work with any speaker. Below 200Hz though it can be very useful.

Phase and amplitude correction for a speaker would be pretty awesome, especially for speakers with a rough response. However, in order for those corrections to be used there must be a way of measuring the speakers using a gated time window (zero room interaction) or you might be chasing your tail fixing problems that aren't really there in the speakers response.

steve f · « **Reply #2 on:** 4 Apr 2014, 04:03 pm »

I've been doing a lot of reading on the subject. The interface between room and speaker system is fascinating. (At least to me

) I've read pro papers, white papers, even some pure snake oil papers. Somehow I missed the Mac oriented system.
Harley52 could you provide a link? Thanks.

Steve

Cheeseboy · « **Reply #3 on:** 4 Apr 2014, 04:32 pm »

I have a DualCore Antimode room correction system. The upgrade in sound quality has been wonderful. I'm buying music like a man posessed. The bass has been significantly tightened up and as a result the wooley bass does not smear and mask midrange frequency integrity. The results in imaging and soundstage improvement are mind blowing. Bass resolution is a showstopper.

As Danny stated correction above 200 hz may not have alot of benefits. I tested this theory in my system as it will correct to 500 hz. This was a subjective test with my old ears only. I thought I heard some room corrections benfits when I went up to 300 hz. I didn't hear any change or improvment when the correction was set above 300 hz. Going higher than 200 hz I thought or perceived the system to have constricted the dynamic range in those higher frequencies. The usual disclaimers would be tacked on here about miliage varies and user perception.

I have not used an outboard room correction sytem loaded into a laptop. I have gotten excellent results with the DualCore. I wouldn't trade it for anything. It has made a profound improvement in my system.

Danny Richie · « **Reply #4 on:** 4 Apr 2014, 04:35 pm »

I'll highlight a few issues with room correction.

Let's say you have a side wall reflection at 3kHz that is pretty strong. What the room correction will do is see it as too loud in that range and it will turn that range down. So that average of direct verses reflected sound is balanced across the board. Let's call this solution A.

Solution B is we put a panel on the wall on both sides of the room that absorbs and defuses that range. Careful adjustments will also allow for a balanced response.

Now the imaging and sound stage of A and B will be very different. Placement of things will be different using solution A as there is more output from the side walls. You may even like A better than B. However, A is falsely created and not natural. Things in the sound stage are not where they should be.

Solution B on the other hand will accurately recreate the true and intended sound stage.

Another problem with room correction is that they are placement dependent. So if you move your measurement mic over a few inches in one direction the measured output levels can change. You might have a peak in one spot and a dip in another range near it that might flip flop if you move to a new measuring position. So the room correction could smooth things out for one spot and make them worse in another.

Cheeseboy · « **Reply #5 on:** 4 Apr 2014, 04:55 pm »

Well said. My room could be further improved with some well placed diffusion and absorbtion. I have some special challenges that evolve around the cosmetic integrity of the space. It is a personal hurdle I plan to overcome. I will say that the improvement to date in adressng the room below 200 hz has been well worth the price of admission.

I have a three butt couch. Fortunatly the AntiMode does allow for averaging three mic placements. Before I found that feature I felt sorry for those on the left and right on the couch.

Hank · « **Reply #6 on:** 4 Apr 2014, 05:42 pm »

"So the room correction could smooth things out for one spot and make them worse in another."
That's a big problem with room correction that doesn't get much "press". If your a loner with your system, that on spot will for the most part "work", but don't sit in any other position. That Dual Core Antimode is 725 Euros, BTW.

roscoeiii · « **Reply #7 on:** 4 Apr 2014, 05:56 pm »

I am a big fan of my DSPeaker Dual Core ($1100), and use its DSP room correction all the way up to 500 Hz. Above that point, it is possible to manually adjust the EQ digitally. Lots of folks, such as Robert Greene at Absolute Sound are big fans of using this digital EQ to smooth out the frequency response of a speaker. At these higher frequencies the room is less of an issue and it is more a correction of factors related to the particular drivers and the crossover. By tweaking the EQ you can get a flatter measuring speaker, or adjust the EQ in ways that give the speaker characteristics that may be more appealing.

IIRC from discussions on Greene's Yahoo group, it is possible through EQ to make a speaker more forward or laid back, warmer or brighter. May not be able to totally overcome other factors related to driver, crossover or enclosure, but seems a great way to dial in a speaker.

The DSPeaker Dual Core is also great for balance control, and can even be used as a preamp via the remote's volume control.

steve f · « **Reply #8 on:** 4 Apr 2014, 06:37 pm »

I am convinced that the loudspeaker itself is the primary factor in good "room interface" for want of a better term. Too many speakers are built without any consideration for the rooms in which they will typically be used. We/ they/somebody needs to do better.

There are some good ideas out there. Danny's dipole subs are a good example. I believe that if we design speakers for use in rooms, most treatments become unnecessary. Suggestions?

Steve

Cheeseboy · « **Reply #9 on:** 4 Apr 2014, 06:45 pm »

Quote from: Hank on 4 Apr 2014, 05:42 pm

"So the room correction could smooth things out for one spot and make them worse in another."
That's a big problem with room correction that doesn't get much "press". If your a loner with your system, that on spot will for the most part "work", but don't sit in any other position. That Dual Core Antimode is 725 Euros, BTW.

Three on the couch is the most I ever get for a critical listen. Three separate measurements and it covers the whole couch very well in terms of correction. I also use the AntiMode as a DAC with my CDP and my laptop. Big upgrade there as well.

It is worth every penny I spent on it. I bought an upgraded power supply and it took it up a notch as well.

harley52 · « **Reply #10 on:** 4 Apr 2014, 08:45 pm »

Steve F,

I'll rack my brain to find where I read that article.

I'll get back to you.

Danny what about the thought of Omni's being least desirable speaker to run correction thru?

Thanks

Danny Richie · « **Reply #11 on:** 4 Apr 2014, 08:59 pm »

Quote from: harley52 on 4 Apr 2014, 08:45 pm

Steve F,

I'll rack my brain to find where I read that article. I'll get back to you.

Danny what about the thought of Omni's being least desirable speaker to run correction thru?

Thanks

It doesn't matter if they are omni or not. The same rules still apply.

And our omni designs have a super accurate off axis response that that tends to maintain a very even room response. Even the vertical off axis is very consistent. So unless there are bad room related problems they shouldn't need any correction.

And above 200Hz room treatments are a much better solution. You really can't fix room problems with EQ. A reflection is still a reflection. Turning down the range where a reflection appears doesn't make it go away.

Below 200Hz responds pretty well as those longer wavelengths load the room pretty evenly. You really don't make the bass cleaner or tighter. You are just making it balanced.

On all of our designs there is a high level of emphasis placed on the off axis response. Any holes in the vertical off axis response or peaks on the horizontal off axis response will cause an uneven room balance. That's one of the reasons our designs work well in just about any room. The off axis is accurate.

jimdgoulding · « **Reply #12 on:** 4 Apr 2014, 09:11 pm »

Well, Cardas' website is a good beginning point for conventional box speakers owners. There has to be a sufficient delay of waveforms intersecting with room boundaries to permit the effort taken in good recordings. Too near surrounding walls can mask this. Studio made recordings are one thing, but recordings made on location are another and it's here where such an allowance makes for an appreciable difference.

rodge827 · « **Reply #13 on:** 4 Apr 2014, 09:43 pm »

+1 for the Dual Core

Cheeseboy · « **Reply #14 on:** 4 Apr 2014, 10:31 pm »

Quote from: Danny Richie on 4 Apr 2014, 08:59 pm

It doesn't matter if they are omni or not. The same rules still apply.

And our omni designs have a super accurate off axis response that that tends to maintain a very even room response. Even the vertical off axis is very consistent. So unless there are bad room related problems they shouldn't need any correction.

And above 200Hz room treatments are a much better solution. You really can't fix room problems with EQ. A reflection is still a reflection. Turning down the range where a reflection appears doesn't make it go away.

Below 200Hz responds pretty well as those longer wavelengths load the room pretty evenly. You really don't make the bass cleaner or tighter. You are just making it balanced.

On all of our designs there is a high level of emphasis placed on the off axis response. Any holes in the vertical off axis response or peaks on the horizontal off axis response will cause an uneven room balance. That's one of the reasons our designs work well in just about any room. The off axis is accurate.

I guess I would say the bass was always tight it was just wooley and pumped up because of reflection problems. Once those were tamed by the AntiMode they were heard as tight and I guess balanced is a better way to put it. With all the room reflections the bass sounded anything but tight. Bloated for sure.

MichaelHiFi · « **Reply #15 on:** 4 Apr 2014, 10:39 pm »

The Dual Core has been the by far, the single biggest upgrade I've ever made in 4 decades. And it's not about what it is designed for, room correction, but on the fly user configurable adjustments to tame bad recordings or late night listening (loudness control) that has been missing since our audio gear (my Yamaha CR820) which had tone controls as well as a loudness control. Of course those tone controls degraded music although I don't remember having a problem with that in my youth.

I have a good room. Bass integration wasn't a problem. Of course my wife being an audio girl, doesn't mind the bass traps and acoustic panels layered around the room. Regardless, the anti-mode seems to mitigate to an extent, room deficiencies.

But that doesn't mean one can have a bad room and the Anti-Mode will fix it. It's built to work under 500Hz and as Danny mentioned (I think) better at up to 200Hz although I found that playing around with various frequencies up to 500HZ might benefit some bad room interactions YMMV. One should apply standard practices where one can.

There isn't really any single configuration. One could play with an infinite amount of settings and save them in a profle which is also on the fly changeable. The documentation is lacking - severely. It outlines many setups but for instance, I've employed 4 subs the other day on a pair of high quality monitors that woof with a Scanspeak 4.5" driver. It will tune to 4 subs but seemingly only using the anti-mode for subs. I use the anti-mode for my preamp! My current setup is having daisy-chained 2 Atom subs with 2 Def Tech HT speakers with built-in subs at the rear, just using the built-in subs. There's really no instruction for how to do that. So I "pretended to simply have a 2.0 full range floorstanders and calibrated to that. One could add calibration points (Placing a mic at various points in a room) to a profile and get amazing results. I did that. It was really good. I still spent time carefully positioning and dialing down the bass manually.

I'm now a convert of many subs in a room

I think 4 is a good starting point

There are things I don't like about it. The screen is too small. The USB receptacle is a mini

It can't digitally do anything above 96/24 although I use it solely as analog in/analog out. The built-in DAC was good enough the optical that it was slightly below my NAD M51 and Oppo BDP105 in performance. For the time being I use the Oppo as a front end and music server.

Having had my eye set on large floorstanders I'm really having to reassess why I need large floor standers when subs now work so well and seem so seamless with whatever monitor I've stuck in my room. I'm thinking 2 of Danny's sealed servo subs might be a good start as the Atoms aren't mine anyway...

seadogs1 · « **Reply #16 on:** 4 Apr 2014, 10:53 pm »

Just out of curiosity has anyone tried the Dirac Live room correction software or the Lyngdorf RP-1 for room correction? Does anyone have any thoughts on how either one or both compare with The Dual Core?

SoCalWJS · « **Reply #17 on:** 4 Apr 2014, 11:20 pm »

I'm tempted by the Dual Core, but can't quite figure out how it would work in my "Frankenspeaker" setup.

Gotta do some research.

If it makes my system any better than it already is, I'll be happier than a Pig rolling in sh.....errrr, mud!

Cheeseboy · « **Reply #18 on:** 4 Apr 2014, 11:37 pm »

John we can discuss this at THE Show in Newport. I have a plan for you. It will work.

On another note. The original poster asked about a digital room correction system for MAC. While I don't know about that system I can tell you this much. Without correction I have a so so system. I don't have a dedicated room or an audio wife. I would give my left nut for either of those. My lousy room has knotty pine that is microphonic and the same bass mode opportunities as about 90 % of the people I've talked to on this forum. Until they make room treatments that resemble country french knick knacks I'm stuck with digital correction. No doubt treating a room with absorbsion and diffraction is the best practice way to go.

The AntiMode has turned a so so system into a MOL (Meaning of Life) system for me. Digital correction is a monster improvement at my house. If the MAC system is even half ass buy it. It will help you enormously.

SoCalWJS · « **Reply #19 on:** 5 Apr 2014, 12:37 am »

Quote from: Cheeseboy on 4 Apr 2014, 11:37 pm

John we can discuss this at THE Show in Newport. I have a plan for you. It will work.

On another note. The original poster asked about a digital room correction system for MAC. While I don't know about that system I can tell you this much. Without correction I have a so so system. I don't have a dedicated room or an audio wife. I would give my left nut for either of those. My lousy room has knotty pine that is microphonic and the same bass mode opportunities as about 90 % of the people I've talked to on this forum. Until they make room treatments that resemble country french knick knacks I'm stuck with digital correction. No doubt treating a room with absorbsion and diffraction is the best practice way to go.

The AntiMode has turned a so so system into a MOL (Meaning of Life) system for me. Digital correction is a monster improvement at my house. If the MAC system is even half ass buy it. It will help you enormously.

Oh - so you've figured it out and I get to wait 2 months to hear the solution?

Looking forward to THE Show though. Gotta hear everybody's feedback on their new gear. Drooling over Sunil's MW Oppo 105.