[gkinberg]

I will start off by describing the configuration of my room, show some pictures and then show some measurements. My speakers are about 17 – 18 in from the rear wall. My speakers are about 8.5 ft apart, from center to center, and I sit about 8.5 to 9 feet away from them. Nearly an equilateral triangle. My speakers are songtoweres with a MTM setup if it matters. The pictures of the living room/listening room start with the listening position and then go clockwise around the room.

[srb]

Not sure what your question is, but I have one.  Why are your TV and center speaker not centered?
 
Steve

[jtwrace]

Not sure what your question is, but I have one.  Why are your TV and center speaker not centered?
 
Steve

Because he didn't hang his TV on the wall I think.  It looks like it's on a stand so the center would block the lower portion of the screen. 

Hang the TV or get it up higher and center the speaker and then measure.

[gkinberg]

I should have mentioned that the panels seen in the pics are some that I inherited from work and have no idea about their exact composition or effectiveness. They definitely appear to be some sort of compressed fiberglass. I have posted near field speaker measurements in another post: http://www.audiocircle.com/index.php?topic=99820.0  (corrected hyperlink)

My first measurement was taken from the listening position with my calibrated dayton mic at ear level using a sweep using REQ and with no panels in place. speakers running full range with out subwoofer, I generally use 1/48 octive smoothing:


Second I used my subwoofer(Boston Acoustics PV5000) crossed at 80 Hz, still no paneling:


Third, No subwoofer; using panels behind speakers and behind listening postion:


Fourth, With subwoofer, with panels:


Of course I was hoping that adding the panels would give me a nice flat response. That clearly didn’t happen. I am basically looking for guidance as to how to improve my frequency response.  I plan to move my speakers around to see if they are at their optimum placement. Nonetheless, if you look at my nearfield measurements it is clear that my room is having a big influence on the frequency response. If you need me to post more info I can do that such as impulse response or group delay trace. However, I don’t know how to generate waterfalls and don’t know what they mean even if I could. Thanks for your help, Garth

[gkinberg]

You guys are fast on the draw. Correct, havent' hung the TV yet. Measurements are for only the left and right channels.

Thanks, Garth

[Jeffrey Hedback]

Hi Garth,

I think you're  doing well, but your expectations from the amount (and type) of panels and your graph presentation is going to cause frustration. 

The panels that I see should help smooth the midrange and your inclusion of the sub has definitely helped the LF range.

Nyal Mellor and myself actually just published a paper on acoustical measurement standards that shows what resolution, how to window and much of the thinking behind the different types of graphs.

When measuring both speakers and the sub your data is going to be valid for the region below 250Hz.  This data should have higher resolution like your 1/48th oct (1/24th oct resolutuion is fine).  Above that you will want to take single speakers only data (and no sub) and use a 1/3 oct (and or 1/6th oct) smoothing.

Take a glance at the above referred paper on comparing L to R midrange data in particular.  You may be better off than you think.

I look forward to the update!

[AJinFLA]

Hi Garth,

Out of curiosity, what did you find objectionable about the perceived sound at the listening position, prior to any panels or measurements?

You appear to have the L wall at a significant distance from the L speaker and an "open" wall to the R. Can't see any lateral issue...with maybe the exception of the entertainment center itself. Did you try moving the speakers towards you another 6"-12" (out from the wall behind them) and toeing them in slightly, etc, etc? (this all presumes you found something objectionable as is).
Also, like Jeff, I would prefer to see 1/6th oct smoothing, as this is a bit closer to how we might actually hear that spectral balance.

cheers,

AJ

[gkinberg]

Hi Jeffery - Thank you for your comments. I haven't read your article yet but I intend to. In addition, I usually only take measurements on the weekends so I probably won't have any new readings for a bit.

One of my main concerns is the large dip just above 50 hz when the mains are running without subwoofer. I could just run with the sub but the sub is not the best so when listening to music I will usually just run the mains.

Hi AJinFLA - Thanks for your comments. Your question is a good one but one that I was dreading simply because I don’t have a good answer for it. On good recordings my system sounds great. On mediocre recordings, my system sounds OK. It may not be realistic but I want it to sound great even when playing mediocre material.  I have one recording where in the opening line, sound starts on your left side almost at 9 O’clock in relation to the listening position and traverses in front of you to almost 3 O’clock. I cannot get things dialed in to where I hear that level of resolution from my system. Also, when I clap my hands in my listening room without the panels I hear a distinct echo/reverb. All those things concerned, I figured that those sound waves bouncing around might be messing with my resolution, hence the need for panels.

Do you guys feel that I can address the large dip around 50 Hz by moving speaker placement?  I also corrected my bad link to my near field speaker measurements in my post above.

[nwboater]

..... On good recordings my system sounds great. On mediocre recordings, my system sounds OK. It may not be realistic but I want it to sound great even when playing mediocre material.  .......

As the owner of Klipsch Heritage speakers I am sometimes painfully aware that mediocre recordings are just that. Don't mean to be flip but 'Garbage in, garbage out'. What I'm looking for is as accurate of reproduction of the source material as possible.

Rod

[AJinFLA]

Hi AJinFLA - Thanks for your comments. Your question is a good one but one that I was dreading simply because I don’t have a good answer for it. On good recordings my system sounds great. On mediocre recordings, my system sounds OK. It may not be realistic but I want it to sound great even when playing mediocre material.  I have one recording where in the opening line, sound starts on your left side almost at 9 O’clock in relation to the listening position and traverses in front of you to almost 3 O’clock. I cannot get things dialed in to where I hear that level of resolution from my system.

I agree with Rod. If it sounds good with good recordings, you're probably all set.

Also, when I clap my hands in my listening room without the panels I hear a distinct echo/reverb. All those things concerned, I figured that those sound waves bouncing around might be messing with my resolution, hence the need for panels.

Personally, if your loudspeakers polar response/soundfield sounds good at the listening position....you may be chasing ghosts.
Doesn't hurt to experiment of course..and if you prefer the sound with panels...

Do you guys feel that I can address the large dip around 50 Hz by moving speaker placement?  I also corrected my bad link to my near field speaker measurements in my post above.

You can definitely affect a dip by moving the acoustic sources. If you are looking for smoothest response over a wider area, multiple LF sources (subs) are the way to go. If you run your mains to <50hz, then experiment with moving the sub around to see if you can achieve smoother response around the LP.

cheers,

AJ

[gkinberg]

As the owner of Klipsch Heritage speakers I am sometimes painfully aware that mediocre recordings are just that. Don't mean to be flip but 'Garbage in, garbage out'. What I'm looking for is as accurate of reproduction of the source material as possible.

Rod

Rod, I agree with you and that is why, in part, that I was reluctant to state the obvious; that I don’t like it when my mediocre recordings sound mediocre on my system.  As an example of what I’m trying to articulate, I was listening to adele’s 21. While I like the CD, I think that it is of average recording quality, not great, not bad but just average.  I find it hard to describe what it is lacking on my system, but maybe dynamics and depth. It just didn’t sound very fleshed out. However, I listened to the CD on a different system and it sounded pretty good. Granted, this different system was of much much higher cost than mine so this was not a very fair comparison.  His revel studios (or salons) probably cost twice as much as my whole system.
I assumed that the shortcoming in my system might be acoustical in nature, hence the treatments. I have noticed improved detail with my panels in place but the change is subtle and not as dramatic as I had hoped or expected. I am starting to think that my expectations might be a little unrealistic. I intend to play around with speaker placement this weekend to determine if I can improve my sound more to my liking.

[bpape]

Once the TV is hung and those large pieces of furniture are not there, the measurements will likely change drastically.  Not saying they're going to be perfect but that large boundary area is certainly making a difference.

I know the space is tight but pulling your seating away from the wall behind you is only going to help tightness and definition.

Bryan