Medium sized but oddly shaped room

[chris_m]

Hi everybody!

I'm working on my room for quite a while now and been reading/learning/trying for weeks. I think i got everything figured out but i'd like to post it to get ideas i maybe missed. I also have a few questions regarding basstraping this specific room but first a (crappy) scratch:



The part I'll be using is the upper half of the room from the window to the middle thin wall. Right now this space is completely empty.
I used the 38% rule (from the 5,7m) to find my listening position but this kinda dictates to place the monitors 160cm apart from me and each other. I'd prefer 180cm but that will get the speakers too close the frontwall.
Right now the speakers are approx 95cm from each sidewall and approx 45 from the frontwall. The speaker height will be between 80-100cm depending on my sitting situation which i didnt plan in yet (ceiling 250cm). I want to keep the range between me and the monitors as free as possible (ala bob katz) as i plan on using the room for mastering, IF i can make it work good enough for my needs.
The things i already decided on are the most basic, first the RFZ (sides, ceiling, maybe back and floor if needed).

The things i'm unsure about:

1.: Will it be a problem to have the speakers that close to the frontwall (45cm)? Should my position move more back regardless of the 38% rule to give the monitors more room from the front?

2.: The window in the frontwall, I'm not sure if it's going to be a problem being behind the speakers, however it starts at about 115cm height so it is not only behind but also above the speakers, slightly angled though due to roof pitch.

3. The front corners: The roof pitch starts at 60cm so i cant place a 1metre high basstrap close to the corners. My plan is to completely pack the corners with 703/705 and cover it with fabric. This basstrapcorner would be about 1m high and maybe 60-70cm into the sides of the room and as deep as it needs to be (20-30cm). Is this a good or a bad idea? Should i leave a distance inside the trap between the corner walls and the 703?
Besides that i will place other basstraps (DIY) with measuring the freq. responce as there seems to be no general rule but to measure ;)

4. I need some kind of visual interface (flatscreen), i plan to place this directly at the frontwall under the window (though centered between the monitors), however due to the closeness of the monitors to the wall it will only be 20cm behind the monitors itself. Is this good enough to keep reflections away or should i think of something else?

5. The thin wall behind the listening position seems to end directly at the centre of the sweet spot, half gets reflected early, other half goes into the room. I guess the best the solution to solve this is an absorber like i would use for the RFZ? I do have a filled CD shelf there right now to offer some diffusion as i wont build traps until i have most things planned out.


If it helps i can post a picture of the room itself tomorrow.

Thanks alot!

Best, Christian


PS: Before i removed all furniture i had a pretty good and even (certainly not flat but also no 20db dips) bass response in this room. So this might not be that much of a problem thanks to the funny shape?. However i did have more problems with imaging but i never had any absorbers on the sidewalls or ceiling as i just started planning to use it seriously some weeks ago.
Please note that 2 of the doors are always open and extend to other rooms (3x3m bottom, and 2x3m upper left) . The walls itself are not concrete, only the wall to the right is. All other walls are of made of ... some thin stuff, i can't find it in my dictionary right now, sorry.

[Ethan Winer]

Originally Posted by chris_m

The part I'll be using is the upper half of the room from the window to the middle thin wall. Right now this space is completely empty.

I suggest you remove that small wall if possible.

I used the 38% rule (from the 5,7m) to find my listening position but this kinda dictates to place the monitors 160cm apart from me and each other.

The 38 percent "rule" is good for your head, but then you should slide the speakers alone the axes as shown here while measure the bass response at high resolution:

Will it be a problem to have the speakers that close to the frontwall (45cm)? Should my position move more back regardless of the 38% rule to give the monitors more room from the front?

Again, the only way to know where is best is to measure as you experiment.

2.: The window in the frontwall, I'm not sure if it's going to be a problem being behind the speakers

Not a problem.

My plan is to completely pack the corners with 703/705 and cover it with fabric.

Perfect.

4. I need some kind of visual interface (flatscreen), i plan to place this directly at the frontwall under the window (though centered between the monitors), however due to the closeness of the monitors to the wall it will only be 20cm behind the monitors itself. Is this good enough to keep reflections away or should i think of something else?

That's fine.

5. The thin wall behind the listening position seems to end directly at the centre of the sweet spot

Best is to remove the wall, second best is to cover it with absorption.

--Ethan

[chris_m]

Hi Ethan, thanks for the tips.

I hope this doesnt sound too stupid: For the corners, does it matter in which orientation i put the 703? Should it stand up like a regular trap and then stacked into the room or can i just put it on the ground and stack it up in height till i reach my 1,20m? That would be much easier to do as i don't need anything to actually keep the stuff from falling.

As this is a rented place i cant do anything about the wall, and i did notice atleast 10dB-20dB of bass buildup in the corner yesterday, so this place needs serious treatment as you said. Should i concentrate on treating it only for bass or try to make the wall acoustically invisible by using broadband absorbtion?


General additions to my first post:

Coming week i'll get my ECM8000 and i'll start treating the corners and reflection points. Ill measure and post as i continue to treat the room. I really want to find out how far i can go with that specific room.

Yesterday i ended up moving my listening position (and speakers) back and forth and i actually do get the most neutral sound close to the 38% spot, for the speakers i found that 1,6m distance works the best.

[Ethan Winer]

Originally Posted by chris_m

For the corners, does it matter in which orientation i put the 703? Should it stand up like a regular trap and then stacked into the room or can i just put it on the ground and stack it up in height till i reach my 1,20m?

I don't understand your question, but the more corner area you treat, and taller, and thicker, the better.

--Ethan

[chris_m]

I'm sorry my english is a bit limited, let me show you a pic to make it clear:

My plan, for ease, is to put it in the corner stacked like this:




Will this work?

[Weasel9992]

Originally Posted by chris_m

I'm sorry my english is a bit limited, let me show you a pic to make it clear:

My plan, for ease, is to put it in the corner stacked like this:




Will this work?

Even if it did, why would you want to do that? You'd use 50 times as much treatment for the same result. Just put two or three 2'x4' pieces together to form a 4" or 6" trap, then straddle the corner with it.

Frank

[chris_m]

The problem is that my corners look like this:




So there's no way but to custom fill the area around the wood. And doing that, stacking it up in height like the on the pic would be alot easier.

So you would say 6" deep is enough for the front corners?
Or is there no "too deep"? The corners are not THAT big so it wont be very costly anyway, approx 150 Euro for both if i go for 60cm depth, 120cm height and 70cm width.

[Weasel9992]

Originally Posted by chris_m

So you would say 6" deep is enough for the front corners?
Or is there no "too deep"? The corners are not THAT big so it wont be very costly anyway, approx 150 Euro for both if i go for 60cm depth, 120cm height and 70cm width.

I should think so...6" would be fine I think.

Frank