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[jimmy neutron]

I want to take the next step in my music system and try out MC's room correction and convolution software. First let me say I don't know, for the life of me, how to figure this out. I've searched the forum but I never got a good enough explanation to help start me off on this journey. So I come asking for help, if anyone would be so kind. I understand that MC's software can bring a dramatic difference to your equipments/room sound. So this is where my journey begins. I will show you pictures of my room, my gear, and maybe with that in mind someone can offer me some suggesstions to help me better use this part of the software. So, let's begin.

Room:
My listening room is really a large 2 part space. The front half is where my 2 channel music only system is, along with some sofa's to sit and enjoy the music. The oppossite end is the second part that is our dinning room. Looking at the pictures you can see how it is situated, furniture layout, floor tile, large windows with drapes and wood blinds, etc. I know I can improve the sound by placing a carpet on the floor, and more wall hangings for sound absorption. But since this room is a main room that is used a lot by visitors, family, and freinds, I really don't have the option to "decorate" it to audiophile standards. This is where digital room correction comes into play. Currently the sound is fantastic. I've used MC's room corection to set the speaker placement distance, and this did help in soundstage a bit. There is a noticable bump somewhere in the lower midrange that I'm thinking is room boundaries. THe high end is great, but even with an impressive soundstage, I'm sure it can be improved upon. Here are a few pictures of the room from different all four corners.









As you can see it has all the characteristics of a loud room with reverberation. In fact, the reverberation is quite low, but room reflections and boundaries play a painfull part in my sound quality.

The equipment:
My equipment sits on a rack in the left side of the front part of the room inside a 3 foot extension that spans the width of the front house. The homes entrance is to the left of this as you can see in the pictures. My gear is McIntosh and consists of a C-39 pre in stereo only mode, an MC7270 power amp driving the ribbons and an MC7200 driving the woofer in my Carver AL-III ribbons speakers. A Monster HTS-5600 power conditioner handles surges, an Emotiva XDA-1 DAC connects to a Musical Fidelity V-Link, and then to a Dell dual-core laptop handling only Win 7 and JRiver. A Denon DVD-2900 pulls SACD duty, while a Definetive 12" 1200 watt subwoofer sits on the right corner. The system is controlled via a 21" ELO touchscreen monitor or my Transformer Prime pad. An Akai GX-747 reel to reel brings back nostalgia. The cables are mostly Monster Cable, with some AudioQuest USB cables thrown in for good measure. I sit 9.5 feet from each speaker on the middle sofa. Behind the gear are 3 windows, usually closed with the wooden blinds and with the drapes.





Test equipment
I have a Daytron calibrated microphone and a USB MBox 2 from Digidesigns. The software I currently have is REW, but if there is another solution anyone wants to recommend me then I'm all ears. My problem is I don't know how to take my measurements, what kind of measurements need to be taken, and what do I do with those measurements once they are taken.





So this is what I have to work with. This is my room. I want to correct for any type of anomolies that should not be here and I want to get as much of an accurate room response as I can. But all this is an area that I don't have too much knowledge in. I know the basics, but now I want to apply that to my room. MC also has both a regular EQ and a parametric EQ built in. I'm assuming these are better than outboard units and since they work in the digital domain I can use them with no side effects? I guess, also, that since I'm going to be correcting for these room anomolies that I will HAVE to use MC's EQ's to achieve the desired effect. Currently I have those settings (EQ) turned off in MC. Will this software (REW) allow me to do the testing and room correction that I want/need? Or is there another piece of software that I should get? How do I go about this? Where do I place the mic/stand? What tests do I run? Do I take different readings from different locations in the room? What do I do with those readings?

Stumped. Thanks a bunch in advance. I know this is a huge subject to tackle. A little guidance is greatly appreciated.

Jimmy

[Scolex]

Have you read through the below post.
Native JRiver 64bit fp convolution engine for Room Correction (FIR filters)?
There is a ton of good information and links to more.

Looking at your system I see one thing I would change right of the bat and that is sub location. Placing a sub in the corner has a tendency to increase
boominess and as you mentioned there is a point where you get a pretty steep rise. Not set in stone but very common.
A tip for finding the best location once you start your measurements is to place the sub where you would normally sit and then take measurements in all
of the possible sub locations to find the best freq response curve.

Very nice setup by the way.

[jimmy neutron]

Thanks for replying Scolex. Yes, the sub is, I think, a big part in the boominess I'm hearing. But I don't think I can move it anywhere else. As you can see in the pics there isin't any more room on that wall. I'm hoping the room correction software and MC's internal parametric EQ can help to smooth things out. I'm assuming that's how it's done? Take measurements, find the problem frequencies, EQ them back to normal? Also, what's your opinion on MC's internal EQ and parametric EQ? Will they degrade the sound as an analog EQ would? Adding noise, etc. Or, because it works in the digital domain, it introduces no noise or won't degrade S/N ratio? I've always hated EQ's, the noise that they add, the constricting of the soundstage, and the lowering of the S/N always kept me from using them. But now with digital EQ's the game has changed. I've not heard anyone specifically talk about MC's EQ before. Maybe now would be a good time to do so since EQing is the first step to achieving a "perfect" room. I'm sure most people that use MC don't use the EQ for fear of any degradation of the signal. I'd love to hear Matt's or JimH's opinion on this. How clean is the EQ in MC and is there any, no matter how small, adverse effect on the music?

One thing I think I will do this coming weekend is to make some decorative wall sound absorption panels. They are cheap and easy to build, can be made to look room freindly, and can play a big role in taming room boundary issues. Opinions?

Jimmy

[NickF]

Hi Jimmy,

I started down this path myself a few months ago with many of the same questions in my mind.  There are some real experts here and if you can tap into their knowledge, you will get some great benefit.

I am not a user of MC's Room Correction or Parametric Equaliser but both run in the 64 bit DSP environment giving huge headroom to reduce noise.

I took the Convolution route.  You can see my struggle here:
 http://yabb.jriver.com/interact/index.php?topic=69312.0

I invested in a good measurement mic and the Audiolense software from http://www.juicehifi.com/index.html. You will need a calibration graph for your mic.

In a nutshell, hugely simplified, you place the mic at your listening position.  The Audiolense software produces frequency sweeps from each channel which the mic picks up and the software analyses.  You chose or create your target frequency response and the software produces correction filters.  The filter is loaded into MC17 Convolution which then corrects in real time (actually at several times faster than real time) your system and room's response.

The effect is quite astonishing.  There are many variables in the process so be prepared to be frustrated and disappointed with the results along the way, but persevere.  It is worth it in the end.  Significant increases in detail are revealed, the sound stage tightens up, although speaker positioning is very critical here, and the frequency response is so much smoother and natural, unnaturally natural, some think, but that is down to the target response you choose.  Give it a try.

Nick

[Urbanito]

Very good equipment, except, for me, the Carver speakers.
Have you consider to rearrange all the room, placing the furniture in different places in order to give the speakers more space to breath, not too close to the walls, including the the corners? Or not using the Sub, since the speakers may have enough Basie if placed in the right position?
In pure stereo we should avoid as much as we can sub woofers or when this is not possible, setting them at a minimum, just to "feel" them, never hear.
The room correction, even digital, in my experience, never does good results. In the beginning it seems it does, but in a longer period the results are quite bad.
There is no substitute to a good relation between the room and the equipment.
Best wishes.
Joao

[Scolex]

My philosophy is to use the hardware settings gain, crossover, phase, channel level and whatever else you may have to get it close by ear.
I start my fine tuning by looking at a smoothed room response curve. If there are any major problems I will see if I can reduce them with
small speaker movements in both position and axis. You may be surprised out much difference a few inches and or degrees can effect the sound.
After that I find the range from highest to lowest SPL so I know how much cut I am going to need to get the biggest peak down even with the
deepest valley at 3db of boost. I will not go above 3db of boost unless I have to, the reason being is for every 3db of boost in SPL you need
~2x the input. By using this rule of thumb I reduce my risk of clipping which is a speaker's worst enemy.

As far as EQs go I am a fan if used properly but most people don't use them correctly. How many times have you looked at someones EQ settings
and not a single band was in the cut position yet they had some cranked way up.

Equalizers in the digital domain are worlds apart from analog technology but it can still cause issue if a person isn't mindful of the potential for clipping.
MC does a lot to help though due to it high bit floating point structure, I don't completely understand it all but I trust the guys serving the cool-aid.

When it comes to the Parametric EQ I only have one problem with it and that is the name because it is so much more than just a PEQ, it is pretty much
a full DSP on it's own. (pic)

I realize you are limited on options for component placement so I spent a bit of time looking at the various items/angles in you pics.
Here are my suggestions take them for what they are worth.
I would swap the table with the monitor and reel 2 reel on it with the 1 with the candle sticks and place the sub underneath it. This would allow you to widen
the sound stage a bit. I would also move the rack inside of the left speaker or place it where the sub is now, not sure because I don't know which cushion on
the couch is the Throne and there isn't a view from directly behind the Throne to get a better representation of the sound stage center.

Just for a bit of background on why, here is what I have read that you want.
  You and the speakers are all equidistant to each other (equilateral triangle)
  The speakers are equidistant to the walls respectively but not equidistant to the side and back walls comparatively (both are say 20" from back and 30" from side).

I am OCD so when I started after my recent move I had my speaker laid out to within fractions of an inch, they went in before the furniture.

Well that is my .02 for the day.

[jimmy neutron]

Thanks for the replies.

@Urbanito, the Carver speakers are the one piece I will never part with. The McIntosh, my Krell gear? I'd part with them first, but never the Carvers. These are the best speakers I've ever heard. I love ribbons.

@Scolex, great tips. It's too late to get into it right now. I'm about to call it a night. I'll pick this back up tomorrow. Again, thanks for your help and suggestions.

Jimmy

[NickF]

Just for a bit of background on why, here is what I have read that you want.
  You and the speakers are all equidistant to each other (equilateral triangle)

This is hugely important.  Even centimetres difference in distance or a couple of degrees change in toe-in for the speakers can make a difference in how solid and precise the sound stage is.  It's very important to get this right first.

Another thing to pay attention to is the ornaments in the room.  Hard on hard surfaces can cause vibrations.  Use self adhesive felt pads on the bottom of all ornaments.

Nick.

[Urbanito]

Hi Jimmy:
I am not saying that the Carver speakers are not good "per se". As you say, they are Ribbons, the more demanding speakers in terms of amplification and, specially of room placement. I will say that you have to built a room for them and not the reverse, so demanding they are, much more than other dipoles.
I had a lot of experience with the Apogee's, the best full ribbon speakers ever built. And it was a tantalizing experience: I almost could see the Nirvana, to loose it when I wanted to approach a little more, so demanding and "idiosyncratic" they were.
Never put them near a wall or a corner! They really need space and this can't be never correct by any equalization system.

Kind regards

Joao

[jimmy neutron]

This is true. They are very room dependant. Unfortunately, in this room, this is all I have to play with. I have had them in the past in different rooms, and in those "right" rooms they are fantastic. Hence todays question: since I "have" to have them in this room and in this set up, how can I use MC's room correction software to "correct" and "make up" for the deficiencies in room placement, boundaries, reflections, and speaker positioning? I will be moving the speakers further out a bit more, but moving them away from the corners? I don't think I can accomplish that. Maybe with the MC software I can clean up those side reflections.

I have a huge concern here with the MC room correction and convolution software. Since these are di-pole speakers, and part of the appeal is the reflection of the music from the rear, as well as from the sides of the speakers, I wonder how the software will treat this? Is MC's room correction and convolution software designed for traditional box speakers where you don't want to have reflections from the rear or side? Or are there settings in the MC where you tell it the speaker type, ie ribbon, di-pole, radiating, and it will adjust accordingly? Will my di-pole radiating speakers be negatively impacted by having the software tell me that I need to reduce and minimize these reflections, when in fact I want...no, need them? Thoughts?

Jimmy

[NickF]

I would strongly suggest engaging with the experts on the main convolution thread mentioned earlier of try the Audiolense forum.  You can't be the first to confront this issue.

Nick.

[jimmy neutron]

Thanks for the link NickF, but the last post in that thread ended back in Feb. 

I have a question about the Audiolense software. In that thread there was a guy having issues with the activation key. Let me just say I effin hate this type of activation. You purchase the software, download it, can't use it, run an .exe for hardware ID, e-mail to company, wait for response, install key, then hope it works? Really?!? I uinderstand this whole hacking a key bit, but this is plain and simple stupidly absurd and calls too much from the people who do buy it. What if I reformat my PC? Add new hardware? It's an HTPC for christ's sake. I add new hardware all the time. Also, as I understand it, it seems because the AudioLense designers are asking for a hardware ID from the computer it's installed on, there is no way to install it, and thus test, multiple computers? I have 3 HTPC's in my home that I would love to test, but if I have to buy 3 different keys then it just becaomes more than absurd, but a nuisance. If I purchase the product, it should be mine - peroid. I should be able to use it as I like on ANY of my computers, no different than buying a flash drive. It is a tool that I purchase, and I shouldn't be limited to using it. Now, I may be wrong about this, but can someone confirm this? Ca I use AudioLense on more than 1 of my HTPC's?

Before I go any further on this journey I need to get the right software first. Audiolense is at the top of my list currently, but if I will be crippled to 1 PC then I'll just skip it and go to another company's software. Does anyone know if AudioLense works like this? And if it does not and it turns out I can use it, then which version do I buy? I have 3 systems - 1 is a 2 channel music only system (pictured here). The other is my Gameroom HTPC 5.1 channel system, and the 3rd is the Family Room HTPC 5.1 channel system. Which version do I need that can handle these?

Thanks again.

Jimmy

[jimmy neutron]

On another note.... would it be a good idea, aka would you guys approve of, having this thread be my one and only thread for setting up room EQ and convolution of my 3 systems? In other words, would anyone object if we talk about in detail how to set up and test my 3 systems here, or should I open multiple threads? The reason I'm asking is mainly to keep things clean and simple. In one thread we can cover more organized ground about testing 2 types of systems (stereo and 5.1) that many people here use as well. Things could get long and deep, but it can still be a good repository I believe. I already have the testing gear (mic, and so far trial software), the stereo gear in my rooms are all set up and ready for testing, and the weekend is upon us and I have plenty of time for testing. What do you guys think?

Jimmy

[NickF]

Thanks for the link NickF, but the last post in that thread ended back in Feb.  

The last post was June 10 2012.  I imagine many of the people involved are still subscribed to it.

I have a question about the Audiolense software. In that thread there was a guy having issues with the activation key. Let me just say I effin hate this type of activation. You purchase the software, download it, can't use it, run an .exe for hardware ID, e-mail to company, wait for response, install key, then hope it works? Really?!? I uinderstand this whole hacking a key bit, but this is plain and simple stupidly absurd and calls too much from the people who do buy it. What if I reformat my PC? Add new hardware? It's an HTPC for christ's sake. I add new hardware all the time. Also, as I understand it, it seems because the AudioLense designers are asking for a hardware ID from the computer it's installed on, there is no way to install it, and thus test, multiple computers? I have 3 HTPC's in my home that I would love to test, but if I have to buy 3 different keys then it just becaomes more than absurd, but a nuisance. If I purchase the product, it should be mine - peroid. I should be able to use it as I like on ANY of my computers, no different than buying a flash drive. It is a tool that I purchase, and I shouldn't be limited to using it. Now, I may be wrong about this, but can someone confirm this? Ca I use AudioLense on more than 1 of my HTPC's?

Well I guess we know where you stand on that!    I have no connection with Audiolense except that I have purchased their software.  There has been a lot of investment of Intellectual Property in the product.  If the licence was portable to any PC, how would they prevent wide scale piracy?  I suggest you contact Bernt Ronningsbakk and ask him how you get a licence to cover your situation. I have found him very reasonable and helpful.  He is passionate about his product.  

Which version do I buy?

You need to read the specs.  Again, email Bernt and describe your different scenarios.  I bought the Audiolense Surround initially but decided that I needed a greater level of correction and adjustment and upgraded to the XO version.

Nick.

[Scolex]

The last post was June 10 2012.  I imagine many of the people involved are still subscribed to it.
Nick.

The post you linked to was last posted in back in February like Jimmy said, the one linked to is the one that was last posted in on June 10.
You must have clicked on the wrong link or something, regardless they are both a good read. Definitely something that should be consumed in
small chunks to prevent overload as there is way to much information to absorb in a single setting.

[natehansen66]

I have a huge concern here with the MC room correction and convolution software. Since these are di-pole speakers, and part of the appeal is the reflection of the music from the rear, as well as from the sides of the speakers, I wonder how the software will treat this?

MC doesn't care what kind of speakers you have. If you go the PEQ route, the filters are determined by measurements that you take. If you go the convolution route, the filters are also determined (in another piece of software) by measurements you take.

Also, you can't target certain reflections with DRC, like a sidewall or ceiling reflection. These reflections will contribute to the frequency response at the listening position in various ways. Software cannot pick and choose reflections or other unwanted acoustical anamolies and remedy them, that's what acoustic treatments are for  .

Also, the directivity of your dipole speakers makes them better when it comes to side wall reflections than a typical box speaker, because of the null output to the sides. In reality this isn't a perfect null, but 20-30db below the on-axis response in my experience. I have dipoles as well, and I aim the sides of the speaker at the first reflection point on the wall to reduce the magnitude of the reflections. I prefer my speakers to be toed in, crossing a bit in front of me, so this works out well. Get them out form the back wall as much as possible as well, that will help the sound immensely. You may have to position them out when you're doing serious listening, then put them back when your wife wants to use the room  

I think Audiolense is supposed to do corrections in the time domain as well as the frequency domain, which is different than just taming peaks and filling notches. I've never used it, but it would be interesting to see if it works. Personally I don't like a frequency response based room correction. The graph might be nice and straight from my listening position, but I get the odd sensation that the music is playing through a tunnel. It doesn't sound quite right to me. I do use some sparing eq to tame nasty peaks, and also to smooth the bass response but that's it. There's plenty of debate about whether DRC works or not, all you can do is try. Doesn't Audiolense have a free trial or something like that?

[jimmy neutron]

Nate, thanks for the explanation. Things are beginning to clear up for me.

Ok, so DRC won't specifically tame certain reflections. Wall treatments need to be added. This I can do. I've been wanting to make some sound absorption panels anyway, and I guess this will be thiss weekends project for me. So the obvious question here is "what kind of panels do I make for what part of the wall/corner"? Should I make some corner RAP's (room absorption panels) or a few wall RAP's, or both? By looking at my room pics can someone best give me a "best guess" or is this something that gets determined AFTER applying DRC?

I *may* be able to re-arrange the system  and move it to the long wall where my 3 pics of my kids are hanging. I had the system here before at one point. I guess moving them to this wal would give me a wider space with no "nook" in which the speakers will sit in. This would also allow me to spread out the speakers maybe 1 or 2 feet wider apart than they are now. But let's leave that as a last thing to do since it could prove very difficult for my wife to swallow. Doing that might cost me a few new pairs of shoes for her (do you guys know what women's shoes cost these days?!?).

I'm still not sure about the working of DRC with di-pole speakers. I'm assuming that DRC software will try to minimize side and rear wall reflections. But I want these reflections, no? Does anyone know how I would run these tests with di-poles?  I went over to the Audiolense site. Boy, what a mess. The pricing is in euro's (!?!). The explanation of the different versions is not very clear at all, and the trial versions add 20-30 db of loss to deliberately curve piracy. You can try it, but you can use it at full functionality. Man, I really hate these types of paranoid companies. I fully understand the issue with piracy, but c'mon. This isin't the new version of Microsoft greatest OS here. It's a DRC software that just a few (relatively speaking) people will use. I don 't think they need to go to such extremes. Anyway, that's just my rant. Back to topic. I can't use Audiolense at full functionality, and I'm not going to pay for it without trying it at full functionality first. This is an expensive piece of software, so I think I'll just move past Audiolense and try another brand. Any recommendations?

Jimmy

[hulkss]

Audiolense may work for you (I say may because your set-up has some issues). You can get your money back on Audiolense if it does not work for you - read the return policy.

Please read up on the Linkwitz Lab site about dipole speakers. He is a big fan of them and an audio genius.

http://www.linkwitzlab.com/

Your ribbon dipoles MUST be further away from the front wall or you are in trouble: http://www.linkwitzlab.com/AES-Munich'09/Reproduction%20as%20live-SL.pdf

Audiolense works fantasticly for me and I am processing 16 separately amplified chanels with it in 7.3 surround.