Aural Enlightenment III - Especiale Pics are up!

0 Members and 1 Guest are viewing this topic. Read 9520 times.

Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #100 on: 12 Nov 2016, 04:57 pm »
These are scaled versions of what I had in stereo recording, not left, then right.






Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #101 on: 12 Nov 2016, 04:59 pm »





Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #102 on: 12 Nov 2016, 04:59 pm »





poseidonsvoice

  • Full Member
  • Posts: 3147
  • Vector - I've got Direction & Magnitude! Oh Yeah!
    • 2 channel/7 channel setup
Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #103 on: 12 Nov 2016, 08:27 pm »
Okay. The area between 100 Hz to 300 Hz has to do with the distance of your speaker to the front wall and side walls. It also has to do with the ceiling and floor but you can't change that. So measure each speaker alone, then start moving the speaker around or just move your mic around if you can't or won't move your speakers. The problem you are having between 100-300 Hz has to do with SBIR (Speaker Boundary Interference).

See here: http://arqen.com/acoustics-101/speaker-placement-boundary-interference/

Read and digest the above thoroughly. Then apply what you have learned. Rinse and repeat  :wink:

We'll deal with your issues below 100 Hz later. They aren't too bad.

1/3 octave smoothing below 300Hz hides all the warts. Don't do it when you are trying to analyze or hone in on the source of the problem  :thumb:

Best,
Anand.

Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #104 on: 13 Nov 2016, 05:31 pm »

1/3 octave smoothing below 300Hz hides all the warts. Don't do it when you are trying to analyze or hone in on the source of the problem  :thumb:


Well I did that because the above reference also did it so you could easily see if you are within a 10 db window. Mine is 11 db.

Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #105 on: 13 Nov 2016, 05:33 pm »
Okay. The area between 100 Hz to 300 Hz has to do with the distance of your speaker to the front wall and side walls.

There is not much room to move them. A tighter grouping pulls them even more away from rear and side but puts them in my lap.

I will have to play with the crossover and gain of the woofer boxes perhaps.

jtwrace

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #106 on: 13 Nov 2016, 07:25 pm »
There is not much room to move them. A tighter grouping pulls them even more away from rear and side but puts them in my lap.

I will have to play with the crossover and gain of the woofer boxes perhaps.
There is one solution but it's not an option I'm sure.  Speakers. 

poseidonsvoice

  • Full Member
  • Posts: 3147
  • Vector - I've got Direction & Magnitude! Oh Yeah!
    • 2 channel/7 channel setup
Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #107 on: 13 Nov 2016, 07:27 pm »
There is not much room to move them. A tighter grouping pulls them even more away from rear and side but puts them in my lap.

I will have to play with the crossover and gain of the woofer boxes perhaps.

Ok. Have you pushed them closer to the front wall to see?

Here is what I did. Take it as a learning exercise. I measured each speaker individually. First with it flush against the front wall. Then I moved it forward in 4-6 in increments and made the same measurements (15-400 Hz). I concentrated on the area from 100-400Hz as I knew SBIR would wreck havoc. I did the same thing with the speaker flush against the side wall. Repeated the same sets of measurements for the opposite speaker. Then measure them together. Hopefully, the distances of each speaker to their respective front and side walls are symmetrical but you might find that the overall 2ch response is better with one speaker 2 in closer to a boundary than the other, for example. After you find a spot where the midbass is as good as it can be (and your imaging/staging isn't compromised), you can optionally, start playing with 4 in and 6 in thick absorbers on the front and side wall immediately behind and around the speaker to improve the measured response. Even the floor! I draw a line from the seated listening position to the speaker and make sure at least my ceiling is treated over that line. My floor is carpeted, but you can lay treatments there too if you want!

Your deep but narrow dip at 80Hz is not really an issue as it is pretty much inaudible with music.

The area between 20-35 Hz that appears boosted may have to do with any LF boost in the Rythmik plate amp, but that's a plain guess on my part.

In addition, turning off the Rythmik sub section and making the above measurements can tell us which drivers occupy which frequency ranges. Then you can play with how the Rythmik's crossover to the main module but check with Salk on that first. The fact of the matter is that getting perfect bass in the same space where imaging/staging are important is extraordinarily difficult. I've done it, but I did it in a way that you would find sac religious  :wink:

And goosing up and playing with the EQ of the woofer boxes electronically is an absolute last resort. Unfortunately, many manufacturers use that as the first as most 2ch fellas are unwilling/unable to do what you have already done. That is, build an acoustically treated room :thumb:

My comment earlier on 1/3 octave smoothing was rhetorical as there are probably a few newbies who are reading this thread. Still, 1/3 octave smoothing is nice to give you reassurance that "enough is enough."

Best,
Anand.

Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #108 on: 14 Nov 2016, 11:46 am »
I had less suck-out at 80 hz back in original speaker location when they were closer to rear and side walls. Peaks are more spread apart, but 80 hz is better.




Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #109 on: 30 Nov 2016, 09:59 am »
One of the nagging things I designed into the speakers were the spikes between cabinets. They would rattle because they were nearly impossible to keep level. I applied goop into the cups and let it almost set up and then would set the tops down to squish it out some more but they would eventually rattle again.

I tried various isolation devices and even had Herbies iso cups with wooden balls in place but is was too unstable for me.

FInally I bull-dogged a less slippery solution so if bumped the tops would not slide off the bottoms using rubber squares on sorbothane sheet. The sticks very nicely and also makes the gap between pieces smaller for a better look.








jtwrace

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #110 on: 10 Jan 2017, 07:29 pm »
What's with all the stuff for sale?  Another redo of the system? 

Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #111 on: 6 Dec 2017, 02:41 am »
So before I install my Gaia's onto the speakers I wanted to see if I could treat or adjust the the room to get rid of the 38 hz suckout and 80 hz bump.

I had a nice phone call with someone at Rythmik today and we tossed around some ideas and he was very helpful in making sure I set up my Exotica amps correctly(crossover, slope, phase).

I was experiencing the above problems that looked like this and was giving me boomy bass. Sure I could turn it down but the room modes were piling up and gain wasn't going to fix it.



Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #112 on: 6 Dec 2017, 02:48 am »
I have been through many movements of the speakers to nearfield arrangements and back out, etc. I also found a guide by Vandersteen that was very easy to follow and it gave me some nice sound and wide soundstage. While close to Cardas, his method was a little different and iterative. But the room modes remained.

So one suggestion was to measure the woofers to make sure they were flat. And they are:



Setting the crossover to 80 hz is important based on the roll off you see they have.

Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #113 on: 6 Dec 2017, 03:04 am »
So I measured all the corners of the room, the center of the speakers, the rack, my shoulders, and I even opened a door to see what would happen if pressure was relieved.

This is messy, but what started to become evident was the different responses around the room (I placed the mic on a box the same 14 inches off the ground at the corners of the room and my seat).



The left rear corner and my seat had the worst bass response. Then the light went on.

Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #114 on: 6 Dec 2017, 03:08 am »
So I placed the mic on my footstool and made a measurement and another at my left shoulder:



The red line is my ear and the blue is my feet. Gee, maybe my ears should be at my feet!?

Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #115 on: 6 Dec 2017, 03:19 am »
So I moved the speakers toward the front wall about the same distance as I moved my chair forward.

I took 12 db's out of the swing of the previous spl position (red previous and green new location). Coincidentally I am now at the 60% mark back from the front wall which is the old rule of thumb for where to sit.

It will be much easier to deal with the 500 hz bump than the 38 and 80 hz issues.




Big Red Machine

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #116 on: 6 Dec 2017, 03:35 am »
Moving my body out of the lumpy zone in the room has clarified all the sound. As everyone knows, if you can clean up the bass, the adjacent bands sound cleaner as well. Soundstaging is decent. Height is okay. I don't have sound outside the speakers yet. Separation of instruments is still good.

I'll keep tweaking.

JakeJ

Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #117 on: 6 Dec 2017, 04:22 am »
Location, location, location!

poseidonsvoice

  • Full Member
  • Posts: 3147
  • Vector - I've got Direction & Magnitude! Oh Yeah!
    • 2 channel/7 channel setup
Re: Aural Enlightenment III - Especiale Pics are up!
« Reply #118 on: Today at 01:51 am »
BRM,

I'm not sure how you did your recent measurements but the general recommendation is (assuming your mic is at the new listening position and height):

1) For frequencies above 300Hz, measure each speaker individually and use no more than 1/6th octave or 1/12th octave smoothing if you are honing in on problem areas. If you measure the speakers at the same time, then you will have phase interactions, comb filtering, and a very poor and inaccurate measurement in the higher frequencies (like a steep rolloff). You want to see how closely the right matches the left speaker in this region which will help with issues relating to imaging, timbre, staging, etc...specifically the area from 250Hz to 4khz would be of concern.

2) For frequencies below 300Hz, you should measure the speakers together preferably without smoothing or 1/24th octave max if you are honing in on problem areas. After you have dealt with the bass issues (whatever they may be, either SBIR related, modal related, etc...), you can then use 1/6th octave for an overall response which is how the ear tends to listen to this region.

As posted it appears you have a steep rolloff where 10khz is about 10 dB down and it is unclear on whether you measured out to 20khz or just put in a 10khz ceiling when you measured with REW.

Best,
Anand.
« Last Edit: Today at 09:34 am by poseidonsvoice »