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Discussion Starter · #1 ·
Hello All,

So after playing with REW and my RS SPL meter as a mic, I decided to get an upgraded mic to see what was really going on so I ordered a CSS Umik Mic.
The unit arrived last week and connected up pretty easily. My calibrated mic is down 1.8db at 8hz so pretty happy.

Here is my room currently
- Height is 2.6m to the Plasterboard then 200mm gap (stuffed with 2x 75mm PolyFiber Insulation) before the 250mm concrete slab.
- All walls are 280mm brick and mortar



I took measurements across these 5 points



Here is my REW measurement file (Five Positions and Average)

https://dl.dropboxusercontent.com/u/26125279/REW/P1-5%209.2%20Setup.mdat

Not 100% familiar on how to read the graphs but looking at the 'general' acceptable waterfalls I seem to have some major problems with lack of decay.
I don't have any treatment but thinking of adding some super chunk bass traps to the corners.

The Average across the five positions does not look too bad but it amazed me to see the HUGE differences in responses across such a small seating area.



I can't do any front corner treatments due to room aesthetics already in place.

Am I right in saying that I am in dire need of bass traps and first reflection points treatments?

Any help or guidance will be greatly appreciated. Thanks.
 

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Not 100% familiar on how to read the graphs but looking at the 'general' acceptable waterfalls I seem to have some major problems with lack of decay.
I don't have any treatment but thinking of adding some super chunk bass traps to the corners.
”Major problem with lack of decay?” For most people this is a good thing. Bass traps are designed to reduce decay, so adding them to your room will only make your “problem” worse.


The Average across the five positions does not look too bad but it amazed me to see the HUGE differences in responses across such a small seating area.
Does your couch have room for five people? If not, no reason to take more than three, on at each seated position.

What strikes me about your individual measurements is that all of them are rather poor, with most being downright dismal. I’ve found that this is often the case when subs are located center-wall. You’ll probably get better results with at least one of them in a corner.

Regards,
Wayne
 

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Discussion Starter · #4 ·
Tidy drawings! What are you using for the processor and speakers/subs?
AVR - Yamaha 3067
Power Amp - Rotel 1575

AVR - BiAmp Kef 900 (Fr L+R)
Rotel - Kef 600c / Kef Iq90 (Rears) / Kef Iq30 (Sides)

Sub 1 - Paradigm Sub15
Sub 2 - DIY Dual Opposed Dayton RSS460 18 (Inuke 6k DSP)
http://www.avsforum.com/t/1471709/dual-opposed-dayton-18-rss460-ho-inuke-6k-dsp-vs-paradigm-sub15-with-svs-as-eq1

I also have the SVS AS-EQ1 - In the build thread above I ran multiple set-ups and really struggled to get a good response without massive EQ. I heard the RS SPL is not very accurate at low frequencies so it was another reason to get the CSS MIC.
 

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Discussion Starter · #5 ·
”Major problem with lack of decay?” For most people this is a good thing. Bass traps are designed to reduce decay, so adding them to your room will only make your “problem” worse.
I guess what I meant to say is that the sound energy in the room is not disappearing quick enough thereby reducing the clarity/quality of the sound. My thinking was that the bass traps would help in absorbing some of the 'excess' LF energy thereby increasing the quality of the bass.

However based on what you seeing from my measurements... bass traps will make it worse?

Does your couch have room for five people? If not, no reason to take more than three, on at each seated position.

What strikes me about your individual measurements is that all of them are rather poor, with most being downright dismal. I’ve found that this is often the case when subs are located center-wall. You’ll probably get better results with at least one of them in a corner.
The couch can sit five people comfortably. Normally we only sit four but have had five people a few times.
I actually moved the DIY DoD18 further down the wall towards the rear corner and did some tests with the AS-EQ1 and the responses got WAY worse below 30Hz.
Both couches are material based (ie No leather) and there is a fluffy carpet in the centre of the room over the laminated wooden flooring.

I've played with the REW room sim for HOURS.
I tried the current setup along with a 3rd sub (I hope to start a DIY LMS-R 15 100L sealed this weekend)
in various positions and the over-riding factor was that I need at least 0.7 absorption on the front, left and right wall in order to get favourable responses.
I will however place the new LMS-R 15 sub in the right corner as in the room sim it seemed to be far more favourable than the left corner, even if it sits in front of the bass trap.

From what I've read online people seem to agree that bass traps are almost mandatory in all but the 'luckiest' rooms. I was planning on building two triangle super chunks 600x600x848mm x 2.6m high. They will be filled with a local product that has a 80kg/m^2 density.

Using the same product I plan on building 3x 1200x1200mm squares (100mm thick) to mount on the front, left and right walls - at first reflection points.

I will maybe take some photos but I cannot put anything (traps or subs) in the front two corners.
I have some flexibility on the left wall and pretty much most of the right wall. The rear is a problem due to massive run of cables required.

Any ideas to try and track down why things measure so badly. The room sounds 'okay' for the most part but I feel that the LF could be must better in volume and quality. At reference type volume the room can sound a little bright.

I've also setup my system to run at SVS settings as it seemed a good compromise.

 
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