[audioblazer]

Did a Rives Level 1. My contractor didn't do an excellent job with my room acoustic particularly the corner bass trap. Recently I measured my room with XTZ room analyser to give me some idea how is my room acoustic. Measured quite decently with a room reverb, RT60 ave 0.4s. From 10 kHz , there was a downslope of abt 10db but what is more disturbing is that from abt 65-30hz there is a 10db suckout and another 8-10db peak around 20hz. Any suggestion how I could deal particularly with the suck out ? Your suggestion much appreciated

[audioblazer]

Correction - what can I do about it

[audioblazer]

My dedicated room is rectangular with no window and only 1 door on the back right about 2 ft from the right corner, adjoining the left corner bass trap . Room size, 14.5ft x 24.5 ft and ceiling 10.5' high . Front wall with a big passive resonator ( curve panel common in Rives design) stuff with rock wool . Helmholtz resonator for 1st reflection. 4 big corner bass trap. 4 2x 4' x2" thick absorption panel along each side of the long wall ( 1 each on the side wall behind speaker). There is a 18" soffit with bass trap. 7 Ceiling panel, 1 x 8' long with a 1" rock wool covered with speaker clothe hanging at a fixed inclination. Speaker positioned 8' from front wall   , 9 ft apart and about 12' from listening position. In other words about 5' from back wall that is filled with LP on Ikea rack. Do not know how to paste image hence long description about the room
Using it for HT and 2 channel, with 2channel as main priority. Feedback is much appreciated
Feedback appreciated

[audioblazer]

Forgot to mentioned that my room is mainly brick wall with concrete plaster and reinforced concrete floor ie ceiling and floor about 6" reinforced concrete , right wall, 4" brick wall and left wall , 2 pieces of gypsum board glued with green glue with a gap of about 4" filled with rockwoolmto theoriginal party brick wall ( this was added for sound isolation so as not to disturb my neighbour when I blast my HT with 2 JL audio F113 sub. A mistake as my wall is no longer symmetrical ) 

[MaxCast]

To add a pic (which I'd love to see) you need to create a gallery.  Use the gallery button in the top menu.  Then just upload any pics you want.  When you post use the insert image icon above the smilies and it will ask you what pic you want to use.

Have you taken the measurement a foot or two closer to the speakers?
Did all you treatment items come from your level 1 purchase?  I would call Rives and see what they had to say first.

[audioblazer]

Ok I will try to upload some photos if I can. Initially I was seated about 10ft from speakers but when I measured it with XTZ , it's suck. I tried shifting speakers backward but it doesn't work. After a few attempts I find that shifting it 2' towards the rear wall  fr my usual seat position give me a flatter freq response. I suppose its a room mode issue. I wonder how accurate is the xtz room analyser. Anyway after few days of speaker position, with more toe in, I get better imaging and like the sound better . Still I can hear a prominent bass peak ( as indicated by my measurement fr 60-175hz). Now I realised why Rives suggested that I move my door because with my current seat position, it affect the positioning of my right surround speaker.
Hope to be able to attach some photos 

[audioblazer]

my dedicated 2channel/HT room

[audioblazer]

room measurement using XTZ room analyser- easy to use








what is the reverb I should expect for a good treated room ?

[Bob in St. Louis]

Impressive room. Well done. 
(Would love to see those pics posted int the HT sticky thread) 

Bob

[audioblazer]

HT sticky thread? I m changing all my racks and when i tidy it up , in a month or so, I will post better photos of my HT stuff. 
would love to have another 2ft of width and wish that Conrad Johnson preamp has balanced output. Then I would prefer to put it near the side wall so that it look neat and I believe having so much stuff in between speaker do affect imaging slightly.
Anyway not too happy with my room acoustic despite spending $$$ on the room. In fact I torn down 1 room just to build this dedicated room. Now I need to live with it. Before I change speaker ( currently using VR4sr) , I hope to sort out the bass issue. Let's hope somebody can give me a solution before I revert back to Rives. There is almost zero opportunity for room acoustic treatment due to lack of expert in Malaysia.   

[MaxCast]

Nice looking room and equipment.  I don't know if that response is that bad for music.  With HT can your processor take it out?
How that you did the gallery check out the systems tab on the top menu bar 

[pelliott321]

very nice room congrats on that.
I use trueRTA and RoomEq as measurment devices. 
Your room curve is actually very good compared to many I gave seen
I certainly would not worry unless you are definitely hearing (or not hearing ) a problem.
As I understand it the brain really does not process suck outs (some say it actually fills in the missing info) very well.
If my room curve looked like that I would be very happy.
Sit back and just enjoy the great music I am sure your system produces. 

[audioblazer]

will probably use more accurate software in the future. Unfortunately some software needs calibrated mike and what is easily available in USA I can hardly find in Malaysia. Eg I cant even get OC703 and I have to use Roxul instead when I treat my room acoustic
To me room acoustic is the most important of component to enjoy quality music. Wouldnt want to spend tonnes of money on gears and software  only to realise that the room acoustic is screwing up the sound.
When I first got the room ready  the imaging was so bad. The front resonator literally rattles. I need to re do it and add a few more layers of wood to really tighten it. Wish instruction were clearer from Rives. However Richard has been most helpful
Yes I am not too happy with the bass hump if you see the next 6ppo freq response

[Ethan Winer]

will probably use more accurate software in the future.

The response graph you showed is pretty clear, and a 15 dB span from peak to adjacent null is not terrible in the grand scheme of things. The only way to improve the bass response (and ringing) further is with more bass traps. You likely have plenty of possible locations, such as the wall-floor corner in the front of the room behind your amps.

--Ethan

[Hebrew Hammer]

I have damn near the same issue with my room.. it makes me mad   

[pjchappy]

I had similar issues, although at different frequencies.  The solution was plenty of room treatments (rigid fiberglass panels).  I do have a nearly square room and I added two 1'x4"x6" bass traps; two 2'x4'x4" panels behind the speakers; two more of the same panels beside the speakers; two more of those same panels behind the speakers; and two more in the opposite corners. 

Here is a measurement pre-treatments:



Here is a measurement that shows an overlay of with treatments and no EQ, along with one with treatments post-EQ:



Here is a measurement with treatments, post-EQ, with the addition of an EQd subwoofer:




My point is that it takes a lot of treatments to alleviate a problematic room (and I could use some more).  The addition of a sub and the addition of EQ further helped to alleviate problem areas.


Paul

[Levi]

Mine was corrected by putting bass traps in key locations and speaker placement.



When you expand the graph, it is smooth.

[MaxCast]

nice work pj.

[McTwins]

Hi
I have the same dimension like your room. Put your two subwoofers in the middle between your speakers close to the wall ( in mono not stereo). Move your main speakers further in to the corners. You can try what seems to be best and do lots of measurements.

Is it before or after measurements you are showing here. Little bit differen't those two measurements, what is right here????

Those cornertraps don't help you below 100Hz no matter who say's what. Throw them away and buy some real Helmholtz resonators (a box tuned at specific freq). Remove the curved panelresonator as well and add some diffusion panels instead. All around the side wall and front wall and ceiling.

I have the same speakers as you.

Pretty bad job they did for you. Specially in the bass region.

To have +/- 15dB in a dedicated listening room is not acceptable. Schould be around +/- 2,5 dB and no ringing in waterfall plot. You have a strong mode at 30Hz.

http://www.audioheritage.org/vbulletin/showthread.php?28924-JBL-3731-and-McIntosh

Look at my last post.

Thanks

[pjchappy]

nice work pj.

Thanks.  It's been a fun process.

So as to not hijack the thread, I cannot emphasize enough the importance of A LOT of room treatments.  As Ethan suggested, you have room for more.  Experiment by moving your subs.  Moving them around can help alleviate any nodes.  I only had one place to put mine (near the corner), but it luckily worked out.

Nice room, though.


Paul