Improvements worth considering?

[jrobbins50]

I've not had anyone take a look at my recent setup and results. To me, the frequency response looks great, but the impulse response could be better. However, I have no clue on how to improve the impulse response. Thoughts as to what it is and anything worthy of doing to make it better? Thanks. JCR

 

[juicehifi]

Are you sure the timing in your measurement is OK?

 

[jrobbins50]

Well, the sweeps sounded normal and the software reported excellent dynamic range. What do you see that makes you question and why might I further provide to help shed light? Thanks, Bernt.

(it’s a UMIK-2….)

 

[juicehifi]

As you said, the pulses were looking a bit fuzzy, and I wonder if the same is the case for the measurements. On most speakers the measured impulse should have a very clean leading pulse followed by a tail that is much reduced in magnitude...

 

[jrobbins50]

Here's the impulse response by speaker and filtered measurements by speaker to make it easier to see. What do you see here?

I don't know if this impacts the impulse response, but I have a difficult listening room space, with floor to ceiling brick to my left and floor to ceiling glass windows to the right, with hardwood flooring. Is the software seeing -- and unable to correct for -- the first reflections against these materials? JCR

 

[juicehifi]

You need to zoom in on the impulse response. So much so that we see every sample apart from the next. Front left will do. The frequency responses are OK.

And please remind me of which speakers you have.

 

[jrobbins50]

Not sure to what level you want the front left impulse zoomed in, but here's one take. Let me know if this shows you what you are looking for.

Front mains are Triangle Celius 202 (2001 Stereophile Class A, low frequency restricted)
Front center is Triangle Sexton 202
Surrounds in ceiling are Dayton 6-1/2" contractor
Front two subs are GoldenEar SuperSub XXLs
Rear sub is a modified Outlaw Audio LFM-1 Plus (better driver installed with more excursion)

I've also attached a photo of the front of the listening space. the brick wall is on the left side of the light colored sectional you can see. Glass sliders out to a deck are on the right side. JCR

 

[juicehifi]

Here's from the demo measurement, which happens to be my own speakers Three way speakers with 1st order crossover between tweeter and midrange, and the two are time aligned..

And this is how I prefer to look at it: The full amplitude, but over a short time span.

It has some low level pre-ringing, which is a measurement artifact when the measurement fades out (the measuremen is linear phase).

But note the clear leading transient. One up and one down, sometimes another ... is very typical fro a conventional speaker. A horn rig may be a bit more fuzzy, but I would expect something similar in your case. When you zoom in as much as you do it is difficult to see the relative magnitude of the high frequency oscillations. Here's what it looks like when I try to do a somewhat similar zoom to yours:

If I filter it, and allow for a higher amplitude, it looks like this:

Please try to do a zoom like the first one I posted .... and the unfiltered version.

 

[jrobbins50]

Bernt, I am unable to zoom to a proper level. This has always been one of my problems using Audiolense XO -- it over or under zooms but I can never get it right. So, I am sending the setup and measurement files, along with my CPD settings, to you via email so you can check directly and let me know what you actually see. Thanks. JCR

 

[jmorris644]

Dear JCR,

I think that you should pour your lovely wife a big glass of wine (maybe 2) and explain to her the importance of acoustics over aesthetics. Then cover that brick wall up with nice looking acoustics and install sliding acoustic panels that you can close over the glass doors. And then invite me over for a good scotch and a good listen.

your friend...

 

[jrobbins50]

Hi Joe. Fancy meeting you on a forum hosted halfway around the globe (folks, Joe is a good friend who lives a half hour from me and just joined this forum, unbeknownst to me). Yes, perhaps some curtains on the right and an art piece acoustic panel will go on the brick wall to the left. But, only after my new Revel F328Bes, C426Be center channel and C783 in ceiling surrounds arrive. Note that the two subs you see are new already — both Goldenear SuperSub XXLs. They are awesome in terms of deep, tuneful bass as compared to old subs. JCR

 

[juicehifi]

Bernt, I am unable to zoom to a proper level. This has always been one of my problems using Audiolense XO -- it over or under zooms but I can never get it right. So, I am sending the setup and measurement files, along with my CPD settings, to you via email so you can check directly and let me know what you actually see. Thanks. JCR

Are you zooming with the mouse?

 

[jrobbins50]

Yes — but I do so over VNC Connect at a different desktop because my server has no mouse, keyboard or monitor. Can I zoom ulna setting the boundaries in some box?

Meanwhile, I sent you by email the various files just to look yourself.Thanks. JCR

 

[juicehifi]

Left speaker here:

Something is wrong with this measurement, I suspect a timing error. The frequency responses are probably OK, though, but this looks like a measurement where a TTD correction may sound worse than a minimum phase correction.

 

[jrobbins50]

Ok so now the question is what do I do?

— Buy yet a third microphone (given prior issues with UMIK-1 and now you are suggesting UMIK-2 isn’t measuring correctly)?

— Remeasure, in which case what might I do to get the timing measured correctly?

Thanks, Bernt. JCR

 

[juicehifi]

I am not 100% not sure what we're looking at here. If I were you I would spend some time trying to make it work before making any further investments.

Perhaps try to measure just the left and right speaker and see how that goes. If that works. Als try short sweeps. 3 seconds.

Does the mic and the dac have a gui where you can set buffer sizes? If so, set them to max. Anyway, as long as you use Asio4All you should set the buffer there to maximum.

Although Asio4All is often the best solution you could also try e.g Asio on the output and something else on the input (all of them) and see how that goes.

And perhaps if you could skip the serrver all together for the measurement session and hook the laptop direcly to the umik and the dac?

And a question for you: Have you done listening comparison between TTD and no TTD? The TTD typically has clearly improved clarity when the measurement is OK. So this is a pretty reliable listening test of the measureent quality. And if the timing error is significant, the TTD tends to sound less transparent.

 

[juicehifi]

I just realized that you sent me a stereo measurement. The timing seems to be better here, but not quite good.

 

[juicehifi]

 

[jrobbins50]

Bernt, I tried using other than ASIO4all with the supported formats, but other formats always got me the PA error when trying to measure. So, I went back to ASIO4all and did three things different this time around: (i) I took out the third sub (not pictured above, but located at the back corner of the room, behind the listening position) and re-did the setup for a 5.2 format; (ii) I reduced the microphone measurement setting to -30dB from the -20dB I had been measuring with and (iii) I shortened the sweeps from 10 seconds to 5 seconds. Measurement this time around claims to have excellent dynamic range.

By manually setting the bottom and left axes for the impulse response (as my mouse zooming ability seems poor), you can see what impulse response I got for the front mains and the center channel (the surrounds look much the same). As member and local friend jmorris644 aptly pointed out, I have a brick wall to the left of the listening position and glass sliders to the right. I have consistently heard bass notes coming from the left wall to this point (which is why jmorris644 suggests acoustic treatments) and do wonder if that throws the measurements' timing off.

This all said, with this new setup and measurement, bass notes now are localized from the front plane of the listening area with the front mains and center channel and I no longer am hearing the bass coming from the brick wall to my left. Best I've ever heard. Perhaps these new impulse response results explain?

I also note that all of your impulse response charts show the pulse starting a zero milliseconds, whereas you can see mine all start around 542 milliseconds. Does that mean anything?

Let me know if you want me to send the latest measurement file directly to you as a followup here. Thanks. JCR

 

[juicehifi]

You have a lot of delay in your charts because you are showing the simulation while I was showing the measurement. This looks very promising, and what you descri be hearing sounds promising too. But I would like to see the the measureed IR's before I am ready to pop the champagne.

 

[jrobbins50]

And here's the frequency response for all speakers with the new setup and measurement as above. JCR

You have a lot of delay in your charts because you are showing the simulation while I was showing the measurement. This looks very promising, and what you descri be hearing sounds promising too. But I would like to see the the measureed IR's before I am ready to pop the champagne.

OK! Which are the “measured IR” files I should your way or post photos of? JCR

 

[juicehifi]

The one labeled "measurement" in the template.

 

[jrobbins50]

Ok, here are all seven of the filtered measurements. Interested in your take now.

On my second listen, I would be wrong to suggest that my room doesn’t need acoustical treatment upon which AL can further correct. There’s probably only so much the software can do to correct for first reflections off my hard surfaces. There’s still some bass directionality, but subjectively, much less.

Bernt, a prod here as well to help me in the other thread on now applying these filters — if they finally look good to you — to DTS, Dolby, etc. 5.1 content from Netflix, Disney+, etc. I particularly need help on understanding the path that the native data is traveling as I connect devices together. Thanks. JCR

 

[juicehifi]

Hi Jrobbins,

I am making this a bit difficult for you, and maybe for me too. But I believe it is in your own interest to be on top of these things.

What you just posted was the frequency response. The IR is the impulse response, the same view as you posted in #19. Except that you were posted the simulation (result after correction) instead of the measurement being corrected. A zoomed-in visual inspection of the measured impulse response is vital information in asessing the measurement quality.

 

[jrobbins50]

OK, let's see if I have the right stuff here for you now, Bernt! I didn't include the surrounds, figuring this should give you the picture pretty well. JCR