point 3 is good. I had a conversation with a friend regarding the use of four subs in each corner. If one used an all-pass network (phase shift with respect to frequency) separately on the rears, it should be possible to steer any room modes outside of the sweet spot. In other words, the rears would be used to act as cancellations to some room behavior.
The idea sounds like fun to try, though my living room at home is sub-optimal due to it being open to the kitchen on the left side.
The idea sounds like fun to try, though my living room at home is sub-optimal due to it being open to the kitchen on the left side.
Both Toole & Geddes go into it a lot deeper with Toole having had the benefit of Harmans big bucks to conduct extensive research. The chapter on taming room nodes is worth the price of addmission all by itself.
dave
dave
One problem is the approximation of room boundaries as rigid.
SYclotron Audio » Biamping the NHT M3.3, part 3
Take a look at the graph near the bottom of the page.
SYclotron Audio » Biamping the NHT M3.3, part 3
Take a look at the graph near the bottom of the page.
Nice ones. The second is very strange (but won't ask you to explain, as i guess it's a very long explanation.
About the third, i think it's not necessair for them to be mono. A guys who works in this field told me that for the most recording techniques (if not all), the bass are practically mono. So there should be no real need to set them mono.
Short version is that outside of the recording studio studies have shown that having the 1st reflection is preferrable.
dave
So you say that first reflections are bad while creating music (recording studio), and that they are fine while reproducing music?
Toole's recommendation is not a radical new concept. The only major difference is treatement of the first lateral reflections. He says it's beneficial for stereo and optional for multichannel.
If you don't want to read his book then you'll find his basic statements here:
http://harman.com/EN-US/OurCompany/Technologyleadership/Documents/Scientific Publications/13686.pdf
Here's a more detailed description of a "Toole room":
Olive Munich AES Presentation on Harman Reference Room
Best, Markus
I have the same problem with 50....60hz gain, my question is, is it better to build a large helmholtz resonator bass trap or several small ones?
sorry for the dumb question 🙂
sorry for the dumb question 🙂
First you should find out what the problem really is by measuring the in room response. If it turns out to be a modal peak, then it's probably easier to use an EQ.
Best, Markus
You cant fix the room, the modes will allways be present to some extend. You can put in alot of absorption and smooth them, but ultimately, some eq will be necessary for a perfect response. Besides, what is easier and cheaper... Ripping apart a whole living room and rebuilding it or setting up a few parametric eq's?
Hi!
Before you made a room you have to simulate it; a golden ratio will avoid most of the problems.
After the room is built you have to do your best efforts to fix it, many times at more cost than the built costs making it first.
That's why we can learn acoustics in order to avoid most of the problems.
Simular with the speaker box. Make it right.
You certainly will be recomnpensated.
I followed the receipt...
Regards,
Before you made a room you have to simulate it; a golden ratio will avoid most of the problems.
After the room is built you have to do your best efforts to fix it, many times at more cost than the built costs making it first.
That's why we can learn acoustics in order to avoid most of the problems.
Simular with the speaker box. Make it right.
You certainly will be recomnpensated.
I followed the receipt...
Regards,
Golden Ratio won't fix any of the problems. The only thing that will help is building your room with completely non-parallel walls, like this:
An externally hosted image should be here but it was not working when we last tested it.
Also, flat floor and sloping ceiling. That should eliminate most standing waves from your room.
Hi!
Alles blau in Munchen?
Several times I've heard that statement: -non parallel walls...
Thanks for your words.
But Mr. Alton Everest tells the opposite.
When you try the golden ratio that's the only way you can have some control of the standing wawes, and calculate the fundamental frequencies and it's harmonics, just in order to avoid redundances and so minimize the peaks and valleys in the spectrum...
Maybe that's why the EAW's SB850 are so good loudspeakers that they came on out of phase...
http://img525.imageshack.us/img525/6100/img0807ar.jpg
Regards,
Alles blau in Munchen?
Several times I've heard that statement: -non parallel walls...
Thanks for your words.
But Mr. Alton Everest tells the opposite.
When you try the golden ratio that's the only way you can have some control of the standing wawes, and calculate the fundamental frequencies and it's harmonics, just in order to avoid redundances and so minimize the peaks and valleys in the spectrum...
Maybe that's why the EAW's SB850 are so good loudspeakers that they came on out of phase...
http://img525.imageshack.us/img525/6100/img0807ar.jpg
Regards,
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No, every room shows a unique modal pattern. Angled walls do not eliminate modes. You make them just less predictable because most mode calculators work with perfectly rigid parallel walls only.
What about rooms that are larger than 18m in each dimension? The biggest modes would be subsonic.... But where you gonna find an 18m ceiling...
What do you mean by "subsonic"? The first mode would be much lower in frequency. But we're talking about acoustically small rooms, not halls.
An EQ can not change the modal behavior of a room. If the output of your speakers are heavy at 50Hz, sure, use an EQ to fix that. If your room has a build-up at the listening position at 50Hz, don't use an EQ to fix that. You should install some bass traps instead.
let's say the variance at some problem frequency is 10dB from one side of the couch to the other. Using an EQ does nothing to change the variance problem.
With enough force, I can use a hammer to drive a screw, but it isn't the correct tool.
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