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Room treatment to fix issues and add depth


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16 minutes ago, minermark said:

If you're married, you have a good wife.:emotion-21:

I actually think that it's a nice looking wall treatment...better than any that I've seen elsewhere.  It also doesn't announce itself as such: I've seen wall hangings that have that type of geometric appearance, too...but that don't do anything for the room acoustics. 

 

Chris

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Just now, Chris A said:

I actually think that it's a nice looking wall treatment...better than any that I've seen elsewhere.  It also doesn't announce itself as such: I've seen wall hangings that have that type of geometric appearance, too...but that don't do anything for the room acoustics. 

 

Chris

I was not commenting on any item, the whole layout, floorplan if you will.

Done in good taste.

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Wow, quite a bit to reply to. Chris, the corner horn imaging guide FAQ is a great read. I am going to experiment a little with the angle of toe in I have the speakers set at. I tried a few different angles some time ago and settled on the current position. I may re- visit the 45 degree angle. Right now the speakers blend behind me, so I will position them so they blend in front of me and see or rather hear what happens. 

2 hours ago, Peter P. said:

I'm gonna question whether it's possible your speakers are too "acoustically large" for the small room.

I hope not, they are too heavy to move. They may seem huge from the pics but they do hide in the corners. Again I am happy with the sound, I just want to be sure I'm getting the best possible performance. I originally had some ESS AMT 

monitors in the room and kg4s, but these work the best so far. The AMTs are a challenge with the dipole design of the top end, and the KG4s needed to be away from the wall which created other issues.

2 hours ago, dirtmudd said:

put the speakers on the long wall

That is the long wall, the room is 12L x 11W x 9H. That is the only wall in the room that has corners that extend out in to the room. The "flow" of the room into the house makes sense too.

2 hours ago, dirtmudd said:

that's nice !

Thank you, it makes me very happy and it sounds great....

2 hours ago, minermark said:

If your married, you have a good wife.:emotion-21:

Thank you, she still thinks I'm nuts.

 

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2 hours ago, Chris A said:

I actually think that it's a nice looking wall treatment...better than any that I've seen elsewhere.  It also doesn't announce itself as such: I've seen wall hangings that have that type of geometric appearance, too...but that don't do anything for the room acoustics. 

 

Chris

Thank you, I built it to absorb some of the reflection off the wall next to my head. I didn't have any issue with my right ear because of the opening from the listening position. It makes a noticeable difference with my left ear. Not perfect but a huge improvement. I tried to make it as aesthetically pleasing as possible while still functional. The improvement this made spawned my interest in other treatments. 

2 hours ago, minermark said:

I was not commenting on any item, the whole layout, floorplan if you will.

Done in good taste.

Thank you, it's my happy place.

 

Hopefully by this weekend I will have acquired a suitable laptop to run REW on, and with some significant hand holding some useful measurement.

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9 hours ago, Schu said:

No one has mentioned that badarse subwoofer... who built that, it gorgeous.

 

That layout very much looks like a near field set up

Thanks schu, that is a table tuba long style wrapped in walnut. All of the great reviews of horn subs are spot on. The bass is clear and articulate and there is a ton of it. I listen at moderate levels, but as the volume rises I feel like the bass starts to really take over in the room. There may be no way around this, but I would like to put it in check with traps if possible. I built all of the audio components in the room, amp, speakers, component rack, cables etc. except for the erc-3, the power distribution center and the plate amp for the sub. I did build an enclosure for the plate amp though. I would definitely consider this a near field setup due to room size. I do wish I did not have the wall directly behind the listening position on the one side, but I just have to live with that. Some day I will build a house with a dedicated listening room that does not have any offending elements, but until then, this will have to do.

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  • 1 month later...

Okay so it took a little longer than I hoped to find the time to get this all together and take some measurements, but it finally happened. I had to wait until no one was home, turn off all the fans, throw the fridge circuit breaker, wait for the AC to cycle off and then I had to wait for it to stop raining! It takes a little while to get everything calibrated but "Getting started with REW: A step by step guide" is very helpful. I started out taking an SPL measurement of each speaker individually with the sub off, and then one with it on. I took the measurements with the mic off the ground pretty much dead center of the speaker top to bottom side to side, and 36" away. This is my first attempt at obtaining any useful information from these results but my amateur eyes it seems that I may need to lower the volume of the sub a little, to get the SPL closer to the speakers.  

L+R+sub and no sub SPL first run.jpg

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Here is the waterfall generated with both the speakers and the sub on. The mic was closer to the listening position for this one. I was not sure where the mic should be for the waterfall so I assumed listening position was the most likely.

water fall L+R+sub.jpg

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That is a really nice looking room! What is the distance from the wall the speakers are on to the back wall with the acoustic treatment (nicely done btw)?

 

I had my LS on the short wall of a 13 x 23 ft. room. The back 4 ft. was the house entryway over to a hallway and the kitchen. I would sit about 15-16 ft. from the speaker. They imaged very well. I had the LS in about a ft. or so from the l/r walls and toed in. In the present house the room was slightly smaller at 11x 21, but it worked too. I sold the LS about three yrs ago, and my replacements aren't in action yet but will be in our music room (former garage at 21 x 20 with almost an 11 ft. ceiling. The almost square room is not ideal, but my Heresy IIs sound great in the room.

 

The LS will only be about 6-7 ft. apart in the room and I will sit about 10 ft. back. It's enough for the drivers to integrate.

 

I look forward to your results with REW.

 

Bruce

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12 hours ago, No.4 said:

Here is the waterfall generated with both the speakers and the sub on.

If you're looking at low frequency only, I find that doing each La Scala one at a time--without sub on--will give you measurements that will be easier to see the actual frequency response without comb filtering.  The human hearing system is quite tolerant of comb filtering, but the eyes are much less tolerant.  Then you can add the sub to see the time domain effects in the spectrum and waterfall plots.

 

Otherwise, if you're doing a full sweep (20-20k Hz), I'd also recommend doing those measurements one La Scala at a time with the microphone at one metre in front of the bass bin/midrange horn mouths.  That will avoid most of the room reflections that can make reading the plots more difficult.

 

Chris

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On ‎6‎/‎24‎/‎2017 at 8:33 PM, Marvel said:

That os a really nice looking room! What is the distance from the wall the speakers are on to the back wall with the acoustic treatment (nicely done btw)?

 

 

Thanks Bruce! the walls are about 11' apart and the listening position is currently just in front of the back wall.

 

On ‎6‎/‎24‎/‎2017 at 8:33 PM, Marvel said:

I look forward to your results with REW.

 

So far messing around with REW has been very interesting. This software has an enormous amount of features, it just amazes me that it is free. What I really need to di is read more about turning the data from the plots in to real life solutions. Unfortunately my free time has been at a minimum lately, but I try to take a few minutes here and there just to keep my sanity. 

 

On ‎6‎/‎25‎/‎2017 at 4:34 AM, Chris A said:

If you're looking at low frequency only, I find that doing each La Scala one at a time--without sub on--will give you measurements that will be easier to see the actual frequency response without comb filtering.  The human hearing system is quite tolerant of comb filtering, but the eyes are much less tolerant.  Then you can add the sub to see the time domain effects in the spectrum and waterfall plots.

 

Otherwise, if you're doing a full sweep (20-20k Hz), I'd also recommend doing those measurements one La Scala at a time with the microphone at one metre in front of the bass bin/midrange horn mouths.  That will avoid most of the room reflections that can make reading the plots more difficult.

 

Chris

I took new measurements with the mic centered 36" away from the bass bin with and without the sub one side at a time. I also messed with the crossover setting of the sub amp as well as the volume. 

L+R Sub and no Sub 2.jpg

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When you get a chance, your later measurements at a yard distance should have smoother phase and group delay plots, and your spectrogram and waterfall plots (without subwoofer) should show a more intelligible result.

 

The downward trend of the frequency response (SPL) plot is a bit more tilted, by about -15 dB at 10 kHz relative to 150 Hz.  Also, the amount of SPL from 100-200 Hz says that you might hear a more fullness overall.  I'd recommend EQing everything from 150 Hz upwards using the one yard measurements, and everything below 150 Hz using the listening position placement of the microphone.  The goal should be to get even SPL vs. frequency across more than just the main listening position, i.e., avoiding "head in a vise" room tuning.

 

I recommend looking at the "excess group delay" plot, generated from the group delay plot by punching the "controls" button, then punch the "generate minimum phase" button, then you can turn on the excess phase plot below the main plot area.  This plot is a good indicator of the quality of the measurement--whether or not early reflections are being mixed with the direct sound measurement--and will help you to determine if you need to put down more absorption on the floor between the La Scala and the microphone position, as well at the side walls just next to the Ls Scala midrange/tweeter mouths. 

 

Strong room reflections can also be seen in the impulse response plot at about 0.5 to 5 milliseconds from the main impulse peak.  These also show up at higher frequencies in the spectrogram plot.  Finding ways to soften or absorbing these strong reflections is a useful endeavor in treating the room acoustically. It's the early reflections that kill the "3-D" imaging potential of the loudspeakers in corners, and just a little absorption in the right places will make a world of difference--on the side walls and on the floor just in front of the Ls Scalas, out to perhaps 2-3 feet from the front face of the loudspeakers.

 

Chris

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Just as an example for talking purposes only, here is a SPL/phase plot, a group delay plot, an impulse/step response plot, and a spectrogram with plotting scales and plotting type choices that I use that helps me to see what I find useful.  YMMV.

 

The reason for using group delay (including and most importantly "excess GD") is that it doesn't wrap like the phase plot--you get to see the noisiness of the measurement.  Notice the horizontal scale on the impulse response, which is using "% full scale" vertical axis.  The spectrogram is using "wavelets" mode and 1/24 octave resolution:

 

5955fb5c84210_JuBellewithCP25onemetreDec38_29_21SPLPhase.png.1bab405a4a184a3340a3856e2e833a2f.png

 

5955ff5a2d370_JuBellewithCP25onemetreDec38_29_21GroupDelay.png.069042ee74759f066c1cb24c48bdd852.png

 

5955fb71ee2f0_JuBellewithCP25onemetreDec38_29_21ImpulseStepResponse.png.4d0148918c2e7f8cd3337677d0e813f0.png

 

5955fb8899070_JuBellewithCP25onemetreDec38_29_21Spectrogram.png.128237b67b85851c1519cec04f9b8923.png

 

[The flatness of the phase in the first plot is due to 1) using an active crossover (including time alignment and EQ), and 2) putting down absorption on the floor and side wall to significantly reduce early reflections for measurements.] 

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On 5/22/2017 at 5:08 PM, Peter P. said:

speakers are too "acoustically large" for the small room

Earlier comments reminded me of this video [disclaimer: this is not a Klipsch setup]: It may be a bit of a non-sequitor at this later stage of the thread, but mention of Mr. Abe's listening room would seem appropriate to any conversation regarding "acoustically large" speakers in a small space; While I cannot articulate the reasons--, it seems to depart from prevailing wisdom, (jump to 6:30 ~7:30, to get camera pan of room); do the floor-to-ceiling, album-lined shelves contribute to rooms effectiveness?... :

Strikes me as inspired. Well considered.

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