# Electronic Room Acoustic Correction



## mikesorensen06 (Jul 2, 2012)

Does anyone have any experience with electronic room correction? Does it work well through all frequency ranges? Does it have any impact on sound stage presentation?

Regards,
Mike


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## natescriven (Jan 12, 2011)

mikesorensen06 said:


> Does anyone have any experience with electronic room correction? Does it work well through all frequency ranges? Does it have any impact on sound stage presentation?


I use Audyssey XT on my Denon 991. It works reasonably well and it does work through all frequency ranges. I did some extra manipulating with the 'manual' setting. I've noticed that some instruments, such as violin, sounds a little more natural with Audyssey turned off. Overall I like Audyssey and now that I've tweaked the manual setting I don't feel like I need to turn it off.


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## mikesorensen06 (Jul 2, 2012)

Interesting regarding the higher frequencies. How does it work with the low frequencies, such as a bass guitar?

Regards,
Mike


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## wgmontgomery (Jun 9, 2011)

I do NOT (usually) use room correction for 2-channel; I love it for movies. 90% of my 2-channel listening is in "direct" mode on my SSP; I DO have a room correction mode saved on my CD input, but it only affects the low frequencies. I use it to smooth-out some room modes for music, but I leave the mids and highs alone.


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## jackfish (Dec 27, 2006)

After the limitations of broadband EQ for high definition audio reproduction became known in the 1970s, the audiophile world concentrated on building or correcting the room to address frequency response nulls and peaks and leaving the audio signal as "pure" as possible. That does not mean that there aren't proponents of electronic EQ for high fidelity systems. Any electronic room acoustic correction will add noise and distortion to a system. For movies it is not much of a problem, for critical music listening on highly resolving equipment it can be deadly.


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## pharoah (Jul 21, 2012)

id like to have room eq for my sub.on my 2 channel system.


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## selden (Nov 15, 2009)

pharoah said:


> id like to have room eq for my sub.on my 2 channel system.


Have you considered the Velodyne SMS-1?

http://www.amazon.com/Velodyne-SMS-1-Correction-Included-Microphone/dp/B000CEGI50


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## mikesorensen06 (Jul 2, 2012)

All in all, when you look at how they work, they add or subtract energy from the original recorded signal so that it acoustically "fits" better into a room. Isn't it really an equalizer?

Regards,
Mike


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## tesseract (Aug 9, 2010)

While I've played around with Trinnov via the Sherwood R-972, I am back to using a passive/pre integrated, the Exposure 2010S. I'll try Trinnov again when I gear up for surround sound, for 2 channel I am good with EQ'ing well below the Schroeder Frequency only.

http://www.trinnov.com/technologies/loudspeaker-room-optimization/

http://www.hometheatershack.com/for...64-i-got-new-toy-sherwood-newcastle-r972.html

http://www.hometheatershack.com/for...sherwood-newcastle-r-972-official-thread.html


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## pharoah (Jul 21, 2012)

selden said:


> Have you considered the Velodyne SMS-1?
> 
> http://www.amazon.com/Velodyne-SMS-1-Correction-Included-Microphone/dp/B000CEGI50


i have seen that before.thanks for the idea though.i have read its a fantastic product.


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## tesseract (Aug 9, 2010)

Even better than the SMS-1 is the miniDSP. It is less expensive, more powerful and REW can suggest filters


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## pharoah (Jul 21, 2012)

tesseract said:


> Even better than the SMS-1 is the miniDSP. It is less expensive, more powerful and REW can suggest filters


thats good to know thanks.


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## Phillips (Aug 12, 2011)

I have a SVS ASEQ-1 with twin Velodyne DD subs (basically SMS-1 inside, with servo control) setup as stereo. which are both discontinued.

I tend to go backwards and forward to which is best, separately, together (current setup).

Personally i like the flexibility and being able to dial in precise filters (Q) of the SMS-1. Coupled with REW, it just tops it off. i can't remember the last time i actually used the SMS-1 measuring software.


There is also going to be a review on Stereophile (Kal Rubinson)on the Antimode 2.0, which is a full range EQ.

Another one is the Yamaha "YDP?" 2006 PEQ which Wayne on the REW forum really likes. This is also discontinued. He says it is low noise etc.


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## JoeESP9 (Jun 29, 2009)

I don't know if this is what the OP is asking but, here goes. I use a Behringer DSP1124P and REW to equalize frequencies from 85Hz down for my sub woofers. Although I have a dedicated and acoustically treated room I have some low frequency non linearity's that no amount of room treatments and/or speaker positioning could cure.

The Behringer and REW enabled me to flatten the low frequency in room response. It was not automatic like Audssey and took me a while to get things to where I was satisfied. No matter, as I don't swap speakers in and out or constantly change things. I'm very happy with the results.


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## Dub King (Aug 10, 2012)

The Behringer Ultracurve Pro DEQ2496 performs a similar duty but does include auto room EQ capability on top of the parametric EQ, dynamic EQ and feedback destroyer functions.



JoeESP9 said:


> I don't know if this is what the OP is asking but, here goes. I use a Behringer DSP1124P and REW to equalize frequencies from 85Hz down for my sub woofers. Although I have a dedicated and acoustically treated room I have some low frequency non linearity's that no amount of room treatments and/or speaker positioning could cure.
> 
> *The Behringer and REW enabled me to flatten the low frequency in room response. It was not automatic like Audssey and took me a while to get things to where I was satisfied.* No matter, as I don't swap speakers in and out or constantly change things. I'm very happy with the results.


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## bracurrie (May 26, 2011)

I have the Behringer DSP1124P and miniDSP. I used REW to fiddle with various crossover points and slopes with my biamped 2 way speakers. I then climbed the curve and learned how to use REW to setup filters for the miniDSP to help me correct a number of room problems. I am not technically trained but found it not too difficult to set levels crossovers and filters. The results are very satisfactory.


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## DanTheMan (Oct 12, 2009)

I used REW for some manual EQing on the pre's menu and got better results in the modal region. My Audyssey version is just the "XT" one however. For any amateur HT guy, it's hard to beat REW's functionality and versatility. Even if it's just to check your auto EQ settings. Really, no EQ should be applied above the modal region, but I think every auto EQ does it. It may be helpful on poor performing speakers.

Dan


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## Kal Rubinson (Aug 3, 2006)

DanTheMan said:


> Really, no EQ should be applied above the modal region, but I think every auto EQ does it.


I am not sure about that. The type of EQ one would apply above the modal region would be different since one would not (could not) correct for modal interference in this region. In addition, Anthem's ARC allows the user to choose an upper limit to the correction band.


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## DanTheMan (Oct 12, 2009)

That's what the science on the subject would say--nothing above the modal region. Above there, correcting the speakers issues would make for a good option. Not many people would find that easy to do however.

You can find evidence for that in Dr. Toole's book or Dr. Oliver's blog. The book is far more thorough however. Alternatively, if you can strum a guitar or mandolin, do it in your living room, and then do it again somewhere else. I think you'll find it still sounds like the same mandolin.

Dan


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## Kal Rubinson (Aug 3, 2006)

jackfish said:


> After the limitations of broadband EQ for high definition audio reproduction became known in the 1970s, the audiophile world concentrated on building or correcting the room to address frequency response nulls and peaks and leaving the audio signal as "pure" as possible. That does not mean that there aren't proponents of electronic EQ for high fidelity systems. Any electronic room acoustic correction will add noise and distortion to a system. For movies it is not much of a problem, for critical music listening on highly resolving equipment it can be deadly.


The rules have changed since then. First, all (well, almost all) sources and processing is digital today. Second, modern DSP is capable of much more sophisticated EQ than anything analog. With all that, the issues of distortion and noise are no longer relevant, regardless of the number of channels or the program content.


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