Thoughts on these graphs...

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WGH

Re: Thoughts on these graphs...
« Reply #20 on: 16 Feb 2022, 07:56 pm »
The peak is still +10 dB relative to the next highest bass peak. I agree it's an improvement, but it's curious that no attempt was made to reduce the peak by another 10 or 15 dB to better blend with the surrounding frequencies. Thoughts?

I can think of three reasons:

1. A bass boost at around 40 Hz is always pleasant as long as it's not too big.

2. It looks like lowering the peak also lowers the 73 Hz dip, probably a compromise.

3. The parametric equalization was maxed out.

JWL.GIK

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Re: Thoughts on these graphs...
« Reply #21 on: 18 Feb 2022, 07:38 pm »
Thank you!

Also, I've got those graphs as well...





Yeah for sure some bass trapping will help a lot, those are very uneven decay times. There are a lot of very strong resonances at 70Hz, 90Hz, and pretty much everything under 50Hz (which isn't uncommon in small rooms, lots of rumbling in the noise floor is common, even background noise as part of the noise floor, etc). The screenshot only went up to 150Hz, but I always look at the entire bass range up to 300Hz or so. Bass trapping helps with all this.

Also there is a LOT more energy under 120Hz than above it -- this can sound exciting and pleasant but if you are after accuracy you might turn the subs down a bit. I usually prefer the subs to be about 6dB louder than the rest of the range but for you it looks more like 20dB louder.

Definitely bass trapping will be hugely important for you.

Chops

Re: Thoughts on these graphs...
« Reply #22 on: 19 Feb 2022, 12:40 pm »
Yes, extremely pronounced (a.k.a. - very annoying) resonance at 70Hz & 90Hz, but especially at 70Hz, but those peaks are from the mains, not the subs.

Also, the subs are a bit lower now, tweaked by ear after listening for the past week instead of sitting in the back corner of the room with the mic in my spot. The subs got lowered by a couple dB, but honestly it doesn't sound as loud as it looks. In fact, the majority of time I don't even think the subs are on unless some really low bass shows up that I know the mains are incapable of.

And yes, bass trapping will definitely help, but all of that low bass energy in the room is nowhere near as noticeable or annoying as those darn 70Hz/90Hz peaks.

Just for fun, giggles, whatever you want to call it, here's full range waterfall and spectrograph charts from the same measurements from last weekend.





I was going to be doing more tuning/tweaking today, but we have decided to go to the https://floridaaudioexpo.com instead, but I'll have all day tomorrow to mess around with REW and the system.

Chops

Re: Thoughts on these graphs...
« Reply #23 on: 6 Mar 2022, 11:14 pm »
Been at it again today with REW, but with the Revel M16's in the system as well as my Topping A90 headphone amp in preamp mode since I sold my Schiit Freya+. The little A90 is quite surprising!

Anyway, started with just the Revel's playing by themselves, measuring and adjusting placement of each one separately of course. I'm still getting that 70 Hz peak as I was with the other speakers, but I was able to lessen it some with placement. They ended up about 10" closer to the front wall and about 12" closer together.

After I got the Revel's playing as nicely as possible on their own, I went back to the left channel only and added in the sub, adjusting gain, crossover point, crossover slope, phase and PEQ. Once that one was as good as I could get it, blending with the Revel, I muted that channel and started on the right channel.

Once each channel was to my liking, I then started tweaking them as a stereo pair. More gain adjustments, and more importantly, more phase adjustments on both subs. Not only are the subs blended extremely well with the Revel's, but the subs are "locked in" on each other now, something I wasn't able to do with the other speakers in the system.

I gotta say, this system is sounding splendid right now. With the PEQ and phase on each sub tweaked to the gills, I've been able to smooth out above and a little below that 70 Hz peak, as well as greatly lessen the dips centered around those 45 Hz and 60 Hz nulls.

Stage width and depth have improved drastically, creating a more lifelike, involved and enveloping sound stage. That 70 Hz peak isn't anywhere near as annoying as it was before, and the subs are working together cohesively, not against each other like before. You can easily tell this as the foundation and overall grunt is stronger, tighter and much cleaner now.

Finally, it feels like I'm actually getting somewhere with this system and room. The next big tweaks of course will be room treatments. Most likely, I'll start with some corner traps up front and a couple absorbers on the wall behind me. After that, some diffusers on the front wall. Lastly, most likely a couple more diffusers on the side walls and maybe a couple more smaller absorbers one the side walls right along side my listening seat.

For now, here's a few shots and measurements...








All graphs are with both channels driven.

12 dB Smoothing...


Decay...


Waterfall...


Spectrograph...

nerdoldnerdith

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Re: Thoughts on these graphs...
« Reply #24 on: 2 Apr 2022, 08:55 pm »
The quarter wavelength of six feet is 47Hz. This looks like boundary interference with the front wall.

Try placing the subs against the wall and crossing over at 80Hz. This should eliminate the problem. You will have to delay the speakers to get them time aligned. REW can be used for this by using the acoustic timing reference when you take the measurements.

Chops

Re: Thoughts on these graphs...
« Reply #25 on: 3 Sep 2022, 06:06 pm »
Wow, how things can change in five months time. Apparently, a lot! Equipment changes/upgrades, major loudspeaker upgrade, and room acoustic treatments.

Four 2" Impression panels and two 4" Alpha panels.








DannyBadorine

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Re: Thoughts on these graphs...
« Reply #26 on: 4 Sep 2022, 02:38 pm »
Are you going to take new measurements??

Chops

Re: Thoughts on these graphs...
« Reply #27 on: 4 Sep 2022, 03:15 pm »
Are you going to take new measurements??

Eventually.

Right now I'm too busy just sitting and enjoying the music.

whydontumarryit

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Re: Thoughts on these graphs...
« Reply #28 on: 4 Sep 2022, 09:45 pm »
Eventually.

Right now I'm too busy just sitting and enjoying the music.
Can you tell us more about the original speakers, what the Revels lacked and why the current (Magnepan?) are best so far?
The measurements vs listening pleasure should be interesting and a Revel’ation pitting modern speaker design objectives against a tried and true design concept that many audiophiles are amazed by in spite of the usually inferior representation of accuracy as depicted by measurement (or the measurer's) techniques not up to the task of evaluating properly anything other than conventional box speakers and I give them the benefit of a doubt even in that case.

I hope you don't keep upgrading because of the 'measurements'.

Chops

Re: Thoughts on these graphs...
« Reply #29 on: 5 Sep 2022, 02:11 am »
First off, the upgrades have nothing to do with the measurements at all.

Why Magnepan? Because to me, they are the Holy Grail of speakers. I owned MGLR-1's over 20 years ago, loved the hell out of them, sold them because I had to move and have regretted it ever since.

Over the years, I've tried all types, brands, sizes of box speakers. None of them truly moved me.

I've tried various bipole speakers from Mirage and Definitive Technology, which sounded good but nothing like that Maggie sound I remembered.

I tried various dipole speakers such as many DIY open baffles, hybrid open baffles from GR-Research, and a couple different electrostats from Martin Logan. These got me a bit closer, mainly because of their true dipolar presentation, but still nothing Maggie level sound.

The main reason I didn't consider buying Maggies for the past 13 years is due to having multiple cats around with very sharp little fish hooks (claws). I finally said the heck with it 5 months or so ago, bit the bullet and purchased a pair of 1.7i's, and a small roll of plastic garden netting that I cut to length and have wrapped around the Maggies. Oddly enough, our cats have never shown a single bit of interest in the Maggies, but that netting is there just in case, and is easily removable if needed.

At any rate, the only way to get that "Holy Grail" Maggie sound was to simply buy Maggies again. I'm glad I did, and I will never venture away from them again. The only thing I will do is possibly move up the Maggie line years down the road if I feel the need to.

And on a somewhat related subject, I am extremely pleased with these SVS PB-1000 Pro subs. They have zero issues blending and keeping up with the Maggies. Which reminds me, I still have my JL e110 subs that I need to sell. Also great subs, just that the SVS subs dig a bit deeper with more oomph for the pipe organ and electronic music I listen to.
« Last Edit: 10 Sep 2022, 12:04 pm by Chops »

Chops

Re: Thoughts on these graphs...
« Reply #30 on: 10 Sep 2022, 07:30 pm »
I do have to retract one statement where I said there was "zero slap echo now". There's still some, but nowhere near as bad as it was. It doesn't ring out as long as it used to, but it's also difficult to tell where it's coming from (side walls, ceiling, maybe front/back walls still?). If I loudly say "AH!" in really short bursts, or clap my hands, I still hear this short echo that has more of a "zing" quality to it that rises in pitch by the time it ends. I would say maybe two tenths to a third of a second at most? So far I haven't noticed it in any music that I've played like I used to before the treatments.


In other news, for the most part, I have preferred the sound of the Maggies with the tweeters on the outside edge for a bit wider sounds stage and a larger center image with very little to no toe-in. Just for giggles, I swapped them a couple nights ago and now have the tweeters on the inside edge with a fair amount of toe-in (tweeters intersect about a foot in front of my head). I was expecting a smaller center image and a narrower, somewhat closed in sounds stage. To my surprise, the opposite happened!

First thing I noticed is that the sound stage now extends out past the side walls by at least a foot or two, well beyond the speakers themselves. There's also a 3D or surround-sound like effect depending on the recording. You're placed IN the recording venue, hearing the natural acoustics and reverb of the live recording venue. Of course, highly engineered studio music does the same, sometimes to extremes. One recording I was listening to (can't remember what it was now) had an acoustic guitar being played close-mic'ed, and I swear it was a foot behind my head to the left. You could actually hear the pick come in contact with the string, and that string sounded like it had a rough texture to it like a round-wound string. However, that late at night I was starting to get really tired (was up 26 hours, 14+ hours of that at work) and failed to make note of the album/track or even put it in my favorites for that matter. It was just something I randomly picked on Qobuz.

The second thing I noticed is that the size of the center image has remained the same (as with the tweeters out) but now that center image is sharper and has more roundness and dimensionality to it. Also, that center image is its own entity between the speakers. In no way does it sound like it's coming from either speaker.

I had these Maggies set up this way a while back when I was experimenting with placement, and I was getting none of this, hence why I had them with tweeters out and very little or no toe-in. All I was hearing before was like a large mono speaker in front of me with some stereo ques here and there set up as they are now, only without any of the room treatments. It's a totally different story now with these GIK panels installed!

Mike-48

Re: Thoughts on these graphs...
« Reply #31 on: 10 Sep 2022, 08:23 pm »
. . . There's still some [slap echo], but nowhere near as bad as it was. . . . it's also difficult to tell where it's coming from (side walls, ceiling, maybe front/back walls still?).
Glad to hear the acoustic treatment has helped.

Slap echo comes from anyplace there are (two) untreated parallel surfaces. So the origin can be easy to find, if you look around. Good luck conquering it!