Room correction in noisy environment (ARC, Dirac, Minidsp, REW)
I live around downtown Dallas in an apartment where there's a considerable amount of traffic and people noise (thanks Katy Trail Ice House). I find it very difficult to find the "quietest" time to run my ARC correction. Will this background noise dramatically affect the outcome? Is it even worth trying?
The first link I provided explains Linn's rational. Linn actually thinks along the lines, how can you do this properly with a microphone given the problems associated with that, such as the background noise you face. Linn has a long diatribe against the microphone in DSP setup on their web site (too busy now to find it).
I am going to demo a speaker with too much bass for my small treated room. So I revisited some DSP systems that I looked at before. The Linn SPACE OPTIMIZATION is considered very good. The Lyngdorf ROOM PERFECT system is I believe older and maybe benefitting from that. I am going to demo with the Lyngdorf 3400 because I want ROON READY. I think both products are likely similar in quality, but they use completely different approaches. At the dealership that carries both, along with the Athem STR preamp with ARC, one guy marginally preferred the Lyngdorf and the other marginally preferred the Linn.
First chance you get, go on-line, look up Fletcher-Munson curves. Then do a search for room reinforcement, nodes, frequency and speaker placement. If you're smart it should take like maybe an hour to understand that no matter how quiet you can get your room, the best you can hope for with DSP is to get it almost as good as you could do by ear. And then only at one volume level. Even then only in the one location. And only at the cost of making things worse everywhere else.
In other words DSP is a colossal waste of time and money.
That's the good news. The better news, hardly anyone bothers to do the reading and thinking to figure this out. There's more technically unsavvy audiophiles than you can shake a stick at. So there's a ready market and you will have no trouble selling your DSP to one of these rubes.
You don’t really need room correction. that would be the wrong direction, IME.
you can’t counter the sound of machine guns going off by adding the the sound of different machine guns at a higher and droning kind of level... to cover it up. It’s an exaggeration, but this is what active room correction is being asked and tasked with doing, in your particular scenario.
You need to drop your noise floor. You need to correct the room noise floor, you need to drop the room noise floor, you need mechanical and acoustical treatment in and of that room.
Active room correction can do nothing good here. All you’ll achieve is some dirty bits of screaming over the noise.
My answer comes from working extensively with someone who is at the top of the trade in the associated technical areas and is tasked with fixing such problems.
It is not necessarily expensive to fix, it just needs to be tackled correctly. eg, window noise, sound coming through windows, through the glass. Some of the security films can work wonders here. (security films have the drawback of making windows very much a non-exit point in case of a fire. Even swat teams can't get through the dang things)
But to me, it sounds like you might have to move, to get anywhere at all with this, at any reasonable level of bother and expense. (I looked up some images on the net re the restaurant, etc)
Also, to be clear, I'm not trying to drown out or compensate for outside noise. I'm just trying to use ARC the way it's intended but afraid my high noise level will botch the measurements completely.
I think this is very often the case with anyone's system. Think about this, when you put on a set of noise cancelling headphones, it's amazing how much quieter it is! Most rooms have high ambient noise naturally even though you don't really perceive it.
So I wonder how many peoples' measurements have been botched due to this.
To answer your question, for the most part, unless the street noises are significant, they are not going to make much practical difference on room correction since the volumes used in correction will still be significantly louder.
Speaker size: unless the speaker has a very large radiation area, the size does not matter significantly, except to make them hard to place, and some speakers are better with more distance to allow for driver integration.
Room correction is an attempt to fix things that are wrong ... and just that, an attempt. It can help, but not a panacea, with the systems that take readings at multiple locations being better but again not perfect. How much work are you willing to put in?
People look at room correction often thinking mainly bass, but they actually work better through the mid-range up to their limit, say 5-8KHz. At higher frequencies, the speaker (on and off axis) dominates alone what you hear, and room correction can attempt to compensate for anomalies in the speaker response that reaches you, but still an attempt.
Down in the bass frequencies ... under a few hundred hz in a typical room, the room and where the speakers are in it is everything. At a given position, frequency response can jump up and down 10db. Room correction will soften this, but not fix underlying issues. You are better off getting RoomEQ, Arta, etc. and measuring at your listening area while moving the speakers around to get the flattest response in the base, and then using room correction to fix what is left ..... or take the next step and learn about bass traps, absorbers, diffusers, etc.
Room correction is often better than nothing at all, but not as good as doing it properly.
Thank you for all the input. I understand that room correction is not a fix all. I have a very tough room and using absorbers, traps, and diffusers is not an option. My aim is to get as close to "better" as possible.
I simply wanted to know if the ambient noise was a total failure. You answered my question when you mentioned the test tone noise should be significantly louder than ambient noise.
Did you run your room correction? If so, how did it go? (I've spent a lot of time building acoustic treatments for my houses through the years, and measuring the effects. Plus I live near Dallas, and am just interested.)
I live in Royse City, on the other side of Rockwall.
I ended up building my own panels about 5 years ago, and again this past year when I moved. I have two sizes, 2'x4' and 16"x4'. All wrapped in different colors of burlap I picked up at a fabric store. Wish I could upload pics. I use REW and a UMIK mic to measure with. With the panels, I am getting good response reduction from 500Hz to 6.5KHz, with 20db reduction from 1.5KHz to around 4.5KHz.
I had a Marantz AVR with Audyssey, but hardly used it. I don't think it handled my speakers well (Magnepans). I currently have a MiniDSP DDRC-88A and use Dirac Live and bass management features. I'm happy with how it all sounds, but I'm really happy with the fact I can measure and get a quantitative result so I know it's not all in my head!
@dtximages I guess the place to start is by getting an SPL meter and checking your ambient noise level. I think as long as it is below ~45dB you'd be okay to run a measurement sweep as long as your speakers were outputting ~75dB - ~85dB, although it could get tricky at some frequencies due to the potential large swing in SPL.
If your ambient noise is really too much, you will need to find a time when it is quiet outside (a holiday?) or do something to block out external noise. Maybe just let your wife know you need like 10-15 minutes of noise one time at night. It should only take about that long once you are familiar with the process, and you can get familiar with it at some other times just by going through it, knowing it is a throwaway calibration.