Suggestions for HT sub upgrade from PB-1000

projix

Novice Member
OK, so after running Audyssey autocalibration, Sub at -11 as was set, crossover at 80hz, everything else off, I get this as a sweep from 2.1:
1615574626453.png


Here is only the sub:
1615574749337.png


And here are only the front towers, sans sub (no crossover):
1615574980493.png


Here is sub overlay Audyssey vs DIRECT mode:
1615575324432.png


Here is speaker overlay Audyssey vs DIRECT mode:
1615575380475.png


I definitely have a big problem at 80hz and it's to do with my room.
Audyssey is EQ-ing the living bejesus out of the sub, speakers are actually not touched all too much.
 

Conrad

Moderator
Is that both mains, or just one?

The sub looks much better with Audyssey.

If you have a null in both the mains and the sub then that can only be fixed by placement, or a second sub to help fill that null.
 

Conrad

Moderator
Yeah, it'll be good to see each main (LCR) individually. There might be something you can do to alleviate that dip.
 

projix

Novice Member
Left and Right main, DIRECT mode
1615577122594.png


EDIT:
Left and Right main, Audyssey, no crossover:
1615577427554.png


I'm gonna try turning them to face straight out instead of towards the listening point!
 
Last edited:

Conrad

Moderator
How does it sound? I have nulls like that but it sounds fine.
I'd need to see the measurements I mentioned earlier to really be able to drill into it.
 

projix

Novice Member
Turning them had zero effect.
Here is the .mdat measurement file, or do you want text files?

It sounded better yesterday with that null gone. Even with all the peaks. That null is a bastard with EDM music. Bass sounds bad.

I am going to try what the DSP on the sub does.
 

Attachments

  • meas.zip
    1.9 MB · Views: 17

Conrad

Moderator
Thanks for that. I'm assuming it's to do with the recording chain (soundcard rather than a USB mic) but the time alignment tool isn't working. It's not even declaring that the measurements don't have a timing reference. Odd.

Have a go with the DSP on the sub and the app, as you say.
 

projix

Novice Member
1615587954140.png


Blue is with maximum possible settings I could do in the sub DSP.
Orange with DSP off. This is only the SUB, with Audyssey applied.

I am going to buy and download the MultEQ32 app now and see how that goes.
The problem is btw at the center listening position mostly. On the sides it's pretty decent.
I think I need to tune the speakers now and probably set the crossover around 70hz for the fronts as until then the sub is now quite flat at all the positions.
 

Conrad

Moderator
It’s looking good. How much boost have you applied and what smoothing do you have on that graph?

If you’re boosting it’s probably worth running compression sweeps to see what that does to your headroom.

Basically you measure, then measure again at 3dB more and so on until either you get to the max volume you need (125dB for reference) or until the response doesn’t increase by 3dB.

Where it doesn’t you know you’re running into the limits of the sub.
 

projix

Novice Member
So I think I am done.

The biggest null is exactly at the center listening position.
What I did was recalibrated Audyssey with 8 points and a little closer to the center listening position (all points within 60cm).
Then I also set the front crossover to 90hz and I boosted the sub at 77hz. The null at 80-90hz is amplified if both speakers are playing and moving that frequency to the sub at the expense of some localization + some DSP on the sub makes it better. It is especially better on +5dB on the sub, which is what I am going to be running.

I attach the final graphs of the 2.1 sweeps, as well as the .mdat file.

Position 1, to the right of MLP:
1615634514568.png


Position 2, MLP:
1615634550733.png

Position 3, to the left of MLP:
1615634601809.png


I think this is as good as it gets. If I do more aggressive EQing I just mess everything up on other listening positions.
This is what the final MLP looks like with the sub 5dB hot (-8 to -3), which is probably where it will be 99% of the time:
1615634706308.png
 

Attachments

  • final.zip
    783.4 KB · Views: 15

Conrad

Moderator
Looks good. You're only boosting 5dB? That's not too bad. I'd still be tempted to run some compression sweeps though, just to see if/where you run out of headroom.

I'm a fan of less EQ. More EQ can make things sound over-processed and can give a metallic sound, especially to the centre channel. Live with it for a bit and see how you like it. You can always change it later.

How does it sound and has it solved your initial problem?
 

projix

Novice Member
There was one thing I didn't adjust and that was phase.
On a sweep - long or short, 40 degrees phase combined with 90hz crossover gets rid of the null without destroying the graphs at the other listening points.

Here's a graph with phase at 40 degrees. I am going to listen to it now...
1615635779493.png


Overlay with phase at 0:
1615635826850.png
 

Conrad

Moderator
Phase is definitely the preferred method of fixing nulls rather than EQ boosts. If you can resolve with phase then that's what you should do. You won't introduce additional headroom issues then either.
 

projix

Novice Member
Thank you for all your help.

I've done some listening tests now and 90hz crossover unfortunately introduces too much bass localization. It feels like the bass does not fill the left side of the room. 80hz and below that is gone.

So what I did was set it to 80hz and play with the sub dsp and phase to get the MLP as the best, and at the same time monitor the other 2 listening points and make sure I'm not completely destroying them.

I ran the sub a bit hotter. It is now 7dB hot. I also enabled Dynamic EQ, but set the reference to 5dB, otherwise at lower volumes there is too little perceived bass. I think something to do with how the ear hears it. But at 0dB it is way overboosted. At 5dB I get no additional bass boost at louder volumes (verified by REW), where the movie listening usually is (-10 to -8 dB for DTS and -6 to -3 dB for Dolby). The optimal phase was 30 degrees (I tried 5 degrees at a time).

I also set the Audyssey setting to "reference" instead of "flat". It introduces a little bit of top end rolloff. Barely noticeable, but it makes the soundstage warmer. The mid-range comp I also turned off, I like the highs better with mid-range comp off.

Here is the final sweep at the MLP with the amp set to -8dB. I don't think I will ever run out of headroom on the bass on this sub. This subwoofer does 113 dB without distortion and I will never ever listen even close to that level in this small of a room, it's way too loud. 100-105 dB will probably be the highest I will ever go to.

I did do some tests at different volume levels and everything looks good, the whole line just goes up and down (well, until the Dynamic EQ is enabled, that boosts bass at low volumes).

1615643904803.png


Before I changed the sub and corrected it:
1615644746002.png


All in all, if I compare to what I had before:
1. The bass sounds massively better now.
2. I don't run out of headroom on the sub and don't heat the voice coil (although the PB2000 Pro is clearly overkill for my room, but the PB1000 was a little underpowered, I think PB 1000 Pro might have been the ticket).
3. I have learned a great many things over the past of few days.

To those that contributed, especially Conrad - THANK YOU!
 

Attachments

  • 80hz xover_ MLP_ 7db_sub_dyneq.zip
    192 KB · Views: 16
Last edited:

Conrad

Moderator
What you're describing (and what DEQ replicates) is a loudness curve. As overall volume gets lower you need an increase in the lower registers to hear/feel the tones at the some SPL. Another way to achieve this is with a fixed House Curve using something like a low shelf filter. That can work well if you always listen at about the same level, which I do.

For max output, bear in mind that the LFE track runs 10dB hotter than the other channels and the THX spec quotes 115dB peaks for the LFE channel. While you wouldn't want to listen to that all day long, explosions and other effects can hit those levels for a few seconds without being crazy.

If you can hit 113dB though then you're fine :)
 

MI55ION

Distinguished Member
Thank you for all your help.

I've done some listening tests now and 90hz crossover unfortunately introduces too much bass localization. It feels like the bass does not fill the left side of the room. 80hz and below that is gone.

So what I did was set it to 80hz and play with the sub dsp and phase to get the MLP as the best, and at the same time monitor the other 2 listening points and make sure I'm not completely destroying them.

I ran the sub a bit hotter. It is now 7dB hot. I also enabled Dynamic EQ, but set the reference to 5dB, otherwise at lower volumes there is too little perceived bass. I think something to do with how the ear hears it. But at 0dB it is way overboosted. At 5dB I get no additional bass boost at louder volumes (verified by REW), where the movie listening usually is (-10 to -8 dB for DTS and -6 to -3 dB for Dolby). The optimal phase was 30 degrees (I tried 5 degrees at a time).

I also set the Audyssey setting to "reference" instead of "flat". It introduces a little bit of top end rolloff. Barely noticeable, but it makes the soundstage warmer. The mid-range comp I also turned off, I like the highs better with mid-range comp off.

Here is the final sweep at the MLP with the amp set to -8dB. I don't think I will ever run out of headroom on the bass on this sub. This subwoofer does 113 dB without distortion and I will never ever listen even close to that level in this small of a room, it's way too loud. 100-105 dB will probably be the highest I will ever go to.

I did do some tests at different volume levels and everything looks good, the whole line just goes up and down (well, until the Dynamic EQ is enabled, that boosts bass at low volumes).

View attachment 1475763

Before I changed the sub and corrected it:
View attachment 1475771

All in all, if I compare to what I had before:
1. The bass sounds massively better now.
2. I don't run out of headroom on the sub and don't heat the voice coil (although the PB2000 Pro is clearly overkill for my room, but the PB1000 was a little underpowered, I think PB 1000 Pro might have been the ticket).
3. I have learned a great many things over the past of few days.

To those that contributed, especially Conrad - THANK YOU!

Looks like a significant improvement. Always good to have headroom. Well done for keeping at it.
 

projix

Novice Member
Watched Avatar at -5 and this setup rocks.
The bass itself is 200% better and juicier. The fact that it now plays all the way to 20hz also makes an insane difference for the LFE track.
 

Conrad

Moderator
If you’re ever in this area let me know, I’ll give you a demo of 5Hz at reference :devil:
 

MI55ION

Distinguished Member
@Conrad.

Hearing you push time alignment, thought I'd do a full refresh and I just finished re-calibrating my system over a couple days, time alignment and levels with very tight tolerance . Didn't realise some of the speakers were off by a bit (due to entropy :D) but it's made a huge difference.

Never had it sounding so good with such seamless 7.1 integration, like spending thousands on upgrades. Proper calibration really is key. :)
 

projix

Novice Member
Oh I am sure you guys have much better (and more expensive!) systems.
I did the best with the room that I had to dedicate to this. There are a lot of compromises, such as couch against wall and so on, but I am very happy now.

The sub upgrade fixed the movies and the proper calibration fixed the bass heavy music.
I must say, the Audyssey algorithm is also very good at what it does, it just can't fix serious issues which vary from listening point to listening point automatically.
 

MI55ION

Distinguished Member
Oh I am sure you guys have much better (and more expensive!) systems.
I did the best with the room that I had to dedicate to this. There are a lot of compromises, such as couch against wall and so on, but I am very happy now.

The sub upgrade fixed the movies and the proper calibration fixed the bass heavy music.

I think you've done a fantastic job in your room, the room treatment alone suggest you take this stuff seriously, all that without turning it into a bat cave is quite an accomplishment. If this was your first attempt with REW, hats off to you, great work there. I suppose in this hobby, the learning never ends, why we do what we do.
 

Conrad

Moderator
Completely agree. It’s a beautiful looking room and you’ve obviously put at lot of time, thought, and care into the treatments and set up. To get that response with a single sub is a great end result and you’re happy with the sound which is always the goal.

I’m not sure I would have had the dedication to measure and create my own cal file!
 

projix

Novice Member
This was the first time I used REW or did any Audio tuning.
I am not a stranger to technology. Just all this stuff was very new to me.
I'd say it also has a very steep learning curve, but those do not scare me.

Thank you for the compliments on the room, I worked hard to make it aesthetically pleasing and have it fit into the whole living room-kitchen space and yet maintaining some reverberation control.
The company that did the Audio project and provided all the acoustic materials was decibel.bg. I am very happy with their service as well.

For the insulation inside the walls and the ceiling I used the material I had left over from insulating my chassis dynamometer (car stuff). It's some expensive heavy duty industrial thing. Works well enough to kill the transmission to the 2nd floor. Also works to quieten an open exhaust V8 engine, but I digress...
 

The latest video from AVForums

AVForums Movies Podcast: We review Dune and ask which is the best decade for horror movies?
Subscribe to our YouTube channel

Latest News

PROMOTED: Which OLED is King? 2021 Shootout at Abbey Road Studios
  • By Promoted Content Poster
  • Published
Hisense TVs get Disney+ on VIDAA smart OS
  • By Andy Bassett
  • Published
Astell&Kern launches entry level SR25 MKII portable music player
  • By Andy Bassett
  • Published
LG rumoured to release 97-inch OLED TV in 2022
  • By Andy Bassett
  • Published
What's new on Blu-ray (UK) for Halloween 2021
  • By Mark Costello
  • Published

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom