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REW measurement feedback

gvfbassline

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Hi everyone,

A close friend and I have started our journey into acoustics for our studio and are currently digesting a lot of information about speaker placement, treatment, room modes, peaks and nulls, SBI, etc. We would like some help in diagnosing issues with our room so we can continue on our journey towards better time alignment and flatter response. Can someone help us with our last batch of graphs from REW?

So for everyones info...Our room is 22 square meters with a measurement of 5.68m long by 3.89m wide. The height of the room is 2.4m. It is a rectangle (duh) with concrete floors, walls, and ceilings. Speakers are Genelec 8351A positioned in an equilateral triangle in the front third of the room. They are approximately 1m from the front wall and 1.5m from the sidewalls. It is worth mentioning that the front wall has two large windows which are symmetrically placed on either side of the midline of the wall. We have treated the front corners with large basstraps (rockwool still in packaging) stacked on top of each other. There are homemade bass traps of 17cm deep rockwool sitting at the first reflection points. There are some panels on the back wall but they are not mounted. There is no treatment on the ceiling.

Thanks so much for your responses and for the forum. The videos on Youtube have been especially helpful in learning many things about audio, consumer and pro-grade alike. I attach a waterfall graph, an SPL graph smoothed at 1/24, and the subsequent psychoacoustic graph. We are looking for advice on what to do about the large dip between 60-100hz...
 

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GDK

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I am by no means an expert (and there are many more knowledgeable people here), but according to Genelec, your monitors may be too far from your front wall. They recommend less than 60cm.


If that doesn’t work, you may need to add a sub (or two).
 

digitalfrost

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It looks pretty good to me. It's fairly even. Personally, I would like more high frequency rolloff than you have and more bass, but that is taste. About the dip, you could try an EQ at ~85hz, Q ~ 2.87 to 4.32 but you need to be aware you can probably pump a lot of energy in there without much happening when it's caused by room modes. So I would not try to fill this completely, 6dB max.

If you're interested in improving on an already good setup, why not get GLM and see what it can do?
 

RogerM

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Have you tried modelling your room and speaker locations in REWs Room Sim tab? It should give you a clue about the reason for the response in the 20 to 200Hz region.
 

Galz

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To know what to do with the dip you would probably first need to know what causes it. Play test tones at problematic frequencies and walk around the room to find the peaks and dips.

For example if your ceiling is about 2.6m high and untreated, that could explain the null at around 65Hz, although the lower your mic is it would lessen the issue and on the floor you'll actually get a peak. As I said above, playing a test tone makes it easy to test if this is the issue, or if it's something else.

The lack of overall bass between 60-110Hz could be a combination of several room modes. The unsmoothed response might give you a better idea of which frequencies are responsible, and then you can play test tones for them to see what is causing them to have nulls.
 

Kvalsvoll

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You have to move out of this. The dip is quite wide, so it will affect balance in the bass. A narrow cancellation dip is not necessarily a disaster, but this is too wide.

It is caused by the speaker position or the listening position in relation to boundaries. Moving your system - both speakers and listening postion, since lp follows speaker pos - can change things into something that is quite acceptable. With 1m to front wall, you may be able to go closer, or you can try to move farther back into the room.

It is likely that this is caused by speaker location. Then it is also possible to fix this by adding a bass-system, since the bass modules can be placed close to the front wall.
 
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