JBL M2 Audiolense Digital Crossovers w/Subs

[andreasmaaan]

It is a single measurement with a sweep at my listening position. Bass MGMT is with Audiolense using Roon’s convolver. The sub crosses over to the mains at 98 Hz.
Let me check the time domain.

How would you recommend to measure things more meaningful?

Ok thanks. Unfortunately I don't have first-hand experience with Audiolense, though I know others here do. But there are a couple of things I can say that may account for why you seem to be hearing something different from what the measurement shows.

Firstly, basing your correction curve on only one measurement is not optimal. It would be better to take multiple measurements from at and around the listening position and to average these, then to use the averaged response to derive your correction curve. This is basically because you have two ears which are not in the same location, and you don't have your head in a vice while listening.

Secondly, it looks to me as though perhaps your correction filter is too finely tuned. You won't hear every narrow-band peak and dip that a measurement shows. In other words, your correction filter may be overcompensating, correcting errors that you don't hear and possibly thereby creating ones that you do hear. It's hard for me to say though without having used Audiolense and without knowing exactly what it did to create the curve it created for your system.

Hopefully others here with experience with Audiolense can chime in here and help out...

 

[Olli]

With whatever tool you have at hand...

PS: I typically measure left/right/and both, since I don't usually listen to just one side or the other...

ok, will try ... what do you think this could prove? I am not lacking bass, it is rather too much at a certain frtequency that I could not figure out yet...

 

[Olli]

Thanks guys. Nothing‘s lacking... More the other way around. I just get too much bass with certain tracks compared to my other set ups. I had a similar experience in another room where adding a 2nd cheap sub diagonally behind me (almost) eliminated the problem. That's why I thought 2 (or 1) more sub(s) at the rear wall could improve this.

Here's the measurement from that set up: One little sub is left behind me in the corner, approx. 1,4 m from me. The bigger sub is 3,5 m in front of me, right to a glass wall. The room is approx 10 m deep. The mains are mounted under the ceiling, same distance a s the bigger sub (3,5 m).

Blue Line is both subs playing, black just the big one front right of me.

@andreasmaan, I took 3 measurements this time, in different positions, for each channel in each set up, and averaged

 

[Olli]

Guess I will try to replicate a smaller version of the @dallasjustice anyway... Smaller meaning no M2s + AHB2s, but the powered 705ps, 2 FM8s in front at the side walls and 2 E112's at the rear wall, using Audiolense

 

[RayDunzl]

ok, will try ... what do you think this could prove? I am not lacking bass, it is rather too much at a certain frtequency that I could not figure out yet...

In my case, I have a hole around 48Hz.

It's the asymmetrical room creating an out-of-phase condition around that frequency.

The left and right look good, and that is what AcourateDRC measures and for which it applies correction, but two-speaker mono bass in that range is cancelled. Stereo bass, less so.

See https://www.audiosciencereview.com/forum/index.php?threads/psychoacoustics-and-i.1960/#post-52019

Post your left/right phase in the bass at the main listening position, for grins.

 

[Ron Texas]

The OP is way braver than I am. Just integrating a sub with LS50's using REW was a chore enough for me.

 

[Olli]

In my case, I have a hole around 48Hz.

It's the asymmetrical room creating an out-of-phase condition around that frequency.

The left and right look good, and that is what AcourateDRC measures and for which it applies correction, but two-speaker mono bass in that range is cancelled. Stereo bass, less so.

See https://www.audiosciencereview.com/forum/index.php?threads/psychoacoustics-and-i.1960/#post-52019

Post your left/right phase in the bass at the main listening position, for grins.

Left

Right

LR

PS: That's back to my home set up, 2 subs in front of me with the compact mains on top

 

[RayDunzl]

Hopefully you didn't delete the data.

In the range of interest, unwrap and individually align (using the +/- 360 degree button) the phase of the response using the overlay window.

My example (linked abobve) that produces a hole:

Phase of Left and Right (individually) at listening position

 

[Olli]

Just getting some better understanding of REW and measurements thanks to @RayDunzl and @mitchco. So this is the chart that @RayDunzl wanted to see and produced for me, thanks for this! Basically the same issue, but 240°.

It turns out that I have a massive delay from my subs that seems to be routed in my DAC Setup - dindn't look at the measurments when I took them in that detail:

I am using a MiniDSP UDIO-8 as explained by @Kal Rubinson in Stereophile - Music in the Round #93 (https://www.stereophile.com/content/music-round-93-minidsp-ripping-sacds); the subs are driven by a MiniDSP SHD, the mains by another DAC. For some reason in this set up there is a delay of almost 30 seconds which is odd since the mains are on top of the subs. Maybe the MinsiDSP 2x4 plugin causes this delay. Will try with another DAC and see if the issue remains.

 

[Ron Texas]

Second time through this amazing thread. I still have some trouble with the idea of crossing over stereo subs @170 hz (or so) with full range speakers. I wonder about the qualitative difference of adding multiple subs. Is the bass better defined, or is the objective to have even bass performance throughout the room? I do realize the M2's have an unusually high maximum output so more subs would be needed to match that.

I also wonder about how much benefit there would be to using subs crossed over @170 hz (instead of 90hz) with something like my LS50's

 

[Krunok]

Second time through this amazing thread. I still have some trouble with the idea of crossing over stereo subs @170 hz (or so) with full range speakers. I wonder about the qualitative difference of adding multiple subs. Is the bass better defined, or is the objective to have even bass performance throughout the room? I do realize the M2's have an unusually high maximum output so more subs would be needed to match that.

I also wonder about how much benefit there would be to using subs crossed over @170 hz (instead of 90hz) with something like my LS50's

Having that particular subs crossed over @170Hz is actually justified: more problems arrise in the 100-200Hz range than in sub 100Hz range, and as he used subs with dual 8" drivers they can play up to 170Hz without cone brakeup and energize that range better than mains. What I find odd is that he don't have all 4 subs working up to 170Hz but 2 working up to 50Hz (actualy one at 47Hz and the other at 50Hz) and other 2 working in the 50-170Hz range.

In other words, it is that 50Hz XO point that I find quite unusual and I don't really understand why he went for it.

 

[Absolute]

Like Dr. Geddes usually say, "whatever works best".

 

[Ron Texas]

Having that particular subs crossed over @170Hz is actually justified: more problems arrise in the 100-200Hz range than in sub 100Hz range, and as he used subs with dual 8" drivers they can play up to 170Hz without cone brakeup and energize that range better than mains. What I find odd is that he don't have all 4 subs working up to 170Hz but 2 working up to 50Hz (actualy one at 47Hz and the other at 50Hz) and other 2 working in the 50-170Hz range.

In other words, it is that 50Hz XO point that I find quite unusual and I don't really understand why he went for it.

My room has an uneven suck out from around 100 to 200 hz. I have to EQ it out, but that costs me headroom with the LS50's. A pair of F8's would fix it. The OP may say somewhere why the other subs run below 50 and the F8's roll off. I could imagine not rolling off the F8's but adding a Sub running @50 hz. I believe Rythmic makes a version of the F8 with a 50hz roll off. Another member is using F8's with TAD's.

 

[vitalii427]

@dallasjustice
Hi, Michael!
Before, you often wrote about updates to your setup. It was very interesting to me. Just curious has anything changed since this thread?

 

[rajapruk]

Very nice system
Can you explain a little more about the perceived sound difference of doing the 4 subs all mono augmenting fullrange M2:s, instead of this 4-way setup you have now?
I would think doing the subs 4-way mono would be better (with my current understanding of things, might be different tomorow… )

I also wonder what is the perceived sound difference of your own crossover settings vs. stock JBL settings?
You could try stock JBL settings with linear phase correction for the crossover added, generating a FIR for that in rephase for example.