# Help me understanding this rew graph



## mikesp1 (Oct 30, 2012)

I have unstalled some acoustic treatment.

24" superchuncks in front corners.
Made frontwall dead with 2" rockwool.
Reflectionpoints treated aswell.

I want to know what you guys think of the measurements?

Spl 1/24 octaaf smoothing


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## mikesp1 (Oct 30, 2012)

Waterfall


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## mikesp1 (Oct 30, 2012)

This is 1/3 octaaf smoothing

What should i use 1/3 or 1/24 smoothing


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## Digione (May 8, 2006)

1/6th octave is the "norm" for full sweep plots with 5dB increments. Please read "posting a graph", it will help you to help other interpret your graphs. Your waterfall should be unsmoothed, same increments as your sweeps and limited to 15 - 200/300 Hz. Your mdat file would be useful for others to review also.


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## mikesp1 (Oct 30, 2012)

Ok thanks will do that with future measurements.

In the mean time what does these curves and wayerfall tell you?


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## EarlK (Jan 1, 2010)

Here's a paper ( written ) by 2 well regarded acousticians where they lay out some guidelines ( as to what to look for when viewing ones own measurements ) and how certain ranges of "numbers", can translate into better sound .

Maybe this will start you on the road to making meaningful connections between what is "seen" & what is "heard" .

:sn:


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## mikesp1 (Oct 30, 2012)

Thanks!

Verry usefull...


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## mikesp1 (Oct 30, 2012)

Well i did a study of the papers.

I think, i am on the right way with my room.

If i could bring those 2 peaks at 55 and 100Hz within 10 db that would be a good starting point to move further and blend the subs inthe system...

Different speakerplacement does not help much, imaging is superbe, so either its gona be further acoustical,treatment or eq. Perhaps i should buy a mini dsp? Not shure, i am actualy a little bit afraid that a dsp can be heard in the system...?


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## Phillips (Aug 12, 2011)

Please list gear(amp, speakes, sub) and measuring mic setup and HT or 2 channel, recordoing studio etc?

What are you hearing mainly e.g. boom too much high end etc. 

Do you like the sound across the full range, what would you like to sound better?

I have bought a Antimode Dual Core 2.0 and it is very versitile. Has made a alot of difference to my system. Still have more to do but have a great starting point.


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## mikesp1 (Oct 30, 2012)

Sunfire tgp4 preamprocessor
Sunfire theatre grand 5x 200w amp
Oppo 105 used as usb dac in for music,,analog to preamp
Klipsch palladium 5.1 system with P17 bookshelf as fronts
2 klipsch Rsw12 sub, aswell as 1 klipsch Sw-112 for testing

Imaging is great, punchy bass, some bass notes are a litlle bit dull (peaks at 55 and 100Hz?) harsness with some music.
Cant blend subs with the mains, i think they do not match the quality of the mains...



50% music 50% ht
Mic behringer ecm 800


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## Phillips (Aug 12, 2011)

Have you tried moving th subs/speakers/listening position around using the RTA of REW?

If the subs have phase adjust that too.

With carefull positoning of subs (specially 2) and speakers crossover, phase and listening position you should be able to smooth the response pretty good. Then look at EQ. Room treatment doesn't smooth 55hz that well.

Is the ECM calibrated?

Post the waterfall graph and 1/6 octave frequency graph as well with the better scaling.


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## mikesp1 (Oct 30, 2012)

Will try tomrrow with RTA, no phase adjust on subs, just 0 or 180 

Altough the bass of the fronts rolls of much much quicker, their bass is much punchier, articulate, refind.
With the subs, it just says booom..no mather what xover or volume, boooom.


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## mikesp1 (Oct 30, 2012)

The last weeks i played most of thentime with the subs at different locations and different xover. Todat i was so frustrated with the sound that i detached them from the system and only played with the mains...it was a relief. Fast bass, punchy, articulate, refind, i was realy happy except that i miss the lowest octaves.

If i could fill the lowests octaves in such a manner i would be a happy happy man.

Right now i am looking for diy subs (maybe si18"), but i think its a hard job finding a system caching up with the dynamics of the Palladiums..'


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## Phillips (Aug 12, 2011)

mikesp1 said:


> Will try tomrrow with RTA, no phase adjust on subs, just 0 or 180
> 
> Altough the bass of the fronts rolls of much much quicker, their bass is much punchier, articulate, refind.
> With the subs, it just says booom..no mather what xover or volume, boooom.


Basically play with what you have 0 or 180%.

Where is your listening position, RTA very good for this?

Post some graphs of the mains on there own (L & R seperate then together). Get them rightr then move to the subs, thats what i did.

I was very close to geeting rid of my two Velodyne DDs, but found out the speakers where contributing to the boom. Now have twin REL Strata 5s and they sound absolutely fantastic, but don't rush and buy / build anything yet, personal opinion.


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## mikesp1 (Oct 30, 2012)

If you are interested, you can follow the progres of my room here:

http://www.hometheatershack.com/for...cinema-music-room-sloped-front-rear-wall.html


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## mikesp1 (Oct 30, 2012)

Further listening is telling me that without subs, the room definitly sounds pretty good, there is an occasional boom in the bassfrequency, probably the peaks at 55 and 100hz, it would be great if i could get rid of those, without further lowering the overall rt60 times above 200Hz


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## Phillips (Aug 12, 2011)

With the subs try middle of each wall e.g. middle of front wall and middle of back wall or middle of each side wall.

Are you playing them as mono?

Attached is what i achieved with the Antimode with my mains only. 

I should have used 1/6 octave smoothing.

The Antimode can also be used for subs only if the user wants.


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## Phillips (Aug 12, 2011)

mikesp1 said:


> Further listening is telling me that without subs, the room definitly sounds pretty good, there is an occasional boom in the bassfrequency, probably the peaks at 55 and 100hz, it would be great if i could get rid of those, without further lowering the overall rt60 times above 200Hz



I use only use the RT60 from 250hz - 8-10khz.

I don't think you should loose this in theory.


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## mikesp1 (Oct 30, 2012)

Phillips said:


> I use only use the RT60 from 250hz - 8-10khz.
> 
> I don't think you should loose this in theory.


More absorbing material on middle of backwall lowers the Rt60 aswell as Spl on that range. So i need a solution that only affects the lower frequencies.


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## mikesp1 (Oct 30, 2012)

Nice looking curves, even your 1/24 octave smoothing is well between specs!

Looks like the antomode does a great job!

For the moment i am playing via digital coax from an asus soundcard to,the sunfire preamp. There i can set the xover for the subs.
However the build in dac's from the Oppo 105 are superior to the sunfire ones, but i loose the sibwoofer channel in stereo mode in that configuration.

So i am looking for a solution where i can use the oppo in stereo mode with subs.
I can set all speakers to small except for the mains and use an Y adapter to the subs but that way the fronts are also playing the low notes and thus limiting the overal volume of the system, maybe a mini dsp can handle this...? In cinema mode am i loosing the lfe channel in this configuration or is it also sending the lfe channel to the mains?

Or i can stream music via dlna to the oppo instead of via the usb dac and dont loose the subwoofer in stereocmode but i am wondering if that would degrade audio quality?


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## Phillips (Aug 12, 2011)

Look at the www.DSpeaker.com website. I am not sure if the Antimode Dual Core 2.0 would work for what you require.I would suggest emailing them for solutions.

Please explain why you don't want the SPL to be reduced in the 300hz up, is it that you will interfere with the absorption?
RT60 should be between 2 -5. 

Can you post the RT60 only, the graph you sent had all.

What is the crossover setup as?

The Minidsp or Antimode would deal with the peaks with ease.

The Minidsp is good for subs, but what i have *heard *not ideal for mains.

Generally think like this: 
1. When adjusting frequencies from 0 - 250hz you are EQing the room. 
2. When adjusting frequencies from 250hz up you are EQing the speakers themselves.

Can you please post the following with 1/6 octave smoothing:
1. Left speaker only in stereo mode (no crossover)
2. Right speaker only in stereo mode (no crossover)
3. Each sub full range (no crossover)
4. Both subs (mono) full range (no crossover)


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## mikesp1 (Oct 30, 2012)

attached mdat file


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## mikesp1 (Oct 30, 2012)

Phillips said:


> Look at the www.DSpeaker.com website. I am not sure if the Antimode Dual Core 2.0 would work for what you require.I would suggest emailing them for solutions.
> 
> Please explain why you don't want the SPL to be reduced in the 300hz up, is it that you will interfere with the absorption?
> RT60 should be between 2 -5.
> ...


here is spl 1/6 octave smoothing,rt60 and waterfall (measured with mains, no sub)


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## Phillips (Aug 12, 2011)

mikesp1 said:


> here is spl 1/6 octave smoothing,rt60 and waterfall (measured with mains, no sub)



Can you measure/post the:
Left speaker only
Right speaker only
Mains together again 

Although it is good to measure speakers together it is very worthwhile measuring separate as well.
Can often find the offending speaker/placement etc.


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## mikesp1 (Oct 30, 2012)

Phillips said:


> Can you measure/post the:
> Left speaker only
> Right speaker only
> Mains together again
> ...


Yes i did measured them separeted also, but there was no much difference, so i posted them togheter.
Its a perfect symetrical room.


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## mikesp1 (Oct 30, 2012)

Phillips said:


> Can you measure/post the:
> Left speaker only
> Right speaker only
> Mains together again
> ...


Yes i did measured them separeted also, but there was no much difference, so i posted them togheter.
Its a perfect symetrical room. I also tried different locations for the mains, wher they are now is best possible place for imaging aswell bassnotes.


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## Phillips (Aug 12, 2011)

Noticed that you have not done the sound card calibration, only entered the ECM8000 mic file. If you can swap the mic file to the MIC/Meter in the preferences and use REW to calibrate the sound card.
What i can see is that: 
The room is of equal dimensions is not ideal. 
Use of seperate measurements can be useful, and also dimensions of room + where you sit etc.
57hz & 100hz are the problem frequencies, which could be easily used with EQ mono bass filters. 
57hz is very hard to deal with room treatment (what i have read). 
100hz is easier. 

With a tone treble control would improve the high end if it sounds better to you.
E.g. my room looses detail/clarity if the treble isn't close to flat, but your room might sound great with a slight downwards slope in the high end. Adjust to taste
I have tried with the Antimode different presets setups e.g. one preset with 2 extra filters with no tone treble control, the other 2 less filters with a slight tilt in the treble tone control. The latter is more detailed, imaging better, though slightly less bright. The instruments stand out a bit more. This setting is my reference, so i will try to improve on this as some people do.
The idea is not to get perfectly flat.

The way i have get the system to improve is toe in specially in the high end.

RT60 between 2-3 is good for home theater due to the sound stage is generally already there because of the surround sound. 3-4 for 2 channel music.

I have setup for 2 channel due to this is what i mostly listen to, then multi channel music then movies.

Hope this helps, this is what i have experienced.


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## mikesp1 (Oct 30, 2012)

Thanks for helping me out.

I will take more measurements later on, in the mean time here are the dimensions of the room:

6.35 x 3.55 x 2.2m high with sloped ceiling on front and rear wall starting at 1.4m high.


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