Chronicle of room treatments to equip room with the ability to play HT at reference levels

[liverpool_for_life]

So, as I continue to wait (and wait) for my new subs, I look for ways to improve on my current subs' response in my room. Talked to Mark Seaton and asked him if there was any way I could use my minidsp NanoAVR HDA. My preference was to put the AVM 60 last in my chain (with the balanced outs) with the Oppo 103 acting as my input switch. So, the only place to put the nanoAVR was between the Oppo and the AVM 60.

I'd need to generate PEQ filters using REW and import them to the minidsp unit. Of course, ARC would need to have been enabled on the AVM 60 prior to this step. Only one problem though: Bass management happened on the AVM 60, so the minidsp would not see the bass managed signal. Mark's recommendation to fix this was to generate filters based on the sub's response up to around the crossover area and then put them on all of the speakers' channels. That'd work!

So, that's what I did and below's the resultant sub response compared to just running ARC. Significant difference in measured response and, of course, during listening.

So much more detail that I'd never heard before in music. Instruments and vocals are also better.

Bass is the foundation on which everything else rests. Get that right and the rest of the stuff can blow your mind away!

 

[elangoas]

Bass is the foundation on which everything else rests. Get that right and the rest of the stuff can blow your mind away!

How have you planned to improve the huge dip between 30 - 40Hz ?, otherwise 10-80Hz seems good after EQ (red trace)..

 

[liverpool_for_life]

How have you planned to improve the huge dip between 30 - 40Hz ?

Adding a pair of these: https://seatonsound.net/product/js-12-subwoofer/

 

[liverpool_for_life]

How have you planned to improve the huge dip between 30 - 40Hz ?, otherwise 10-80Hz seems good after EQ (red trace)..

Sorry, I think you were looking for more detail wrt placement as well. The current plan is:

1. Make speaker stands for mains.

2. Move current subs from their current positions to 1/4 width away from the respective side walls along the front wall.

3. Move the diffusers up from their current position on the rear walls and see if I can accommodate the dual JS-12's along the rear wall, right opposite the current subs.

This ought to take care of my nasty length modes. Play around with gain and delay settings for the JS-12's to see if it will also fix the width mode. If that doesn't work:

4. Move the JS-12's 8 ft from the rear wall and put them alongside the wall, either side of my LP. Adjust sub settings. If that doesn't work:

5. Put one JS-12 up front, right in the middle. Find the best place for the other JS-12.

That's it. Now, if only I could get them home..

 

[liverpool_for_life]

What can I say? I wish I'd asked Mark before about how to integrate the minidsp into my system before instead of just fixating on the bass management issue. There is almost always an acceptable workaround for these sorts of issues. REW PEQ on top on ARC rules!

Movies and music just sound a level above than before. Getting closer to accurate bass produces subjective improvements that can't be imagined by looking at measurements alone.

Wow, just wow!

 

[elangoas]

Sorry, I think you were looking for more detail wrt placement as well. The current plan is:

Not a problem.. Yes, i was hoping if you would try to re-position the present dual subs in the room to reduce that dip before you add two more subs..

Cool.. So you have anyways planned to re-position it..

 

[cmsajith]

Lucky to have atleast 10ft at the rear to run diffusers

 

[matbhuvi]

Bass is the foundation on which everything else rests. Get that right and the rest of the stuff can blow your mind away!

View attachment 37509

That's pretty good RTA curves. Can you post the 20 - 20K full spectrum as well.

I am also doing my dedicated HT room inside my tiny apartment space. This is where i am currently. This is without EQ. I am not sure it is worth fighting against the 30hz dip which has very narrow Q.

 

[liverpool_for_life]

Can you post the 20 - 20K full spectrum as well.

Only have the pre-ARC curves for now from my latest Genesis calibration (currently EQ'ing out to 5K as I wait for my front wall to be treated):

 

[liverpool_for_life]

So, demoed The Dark Knight to my cousin yesterday. At reference. She dropped her coffee tumbler in the middle of it. Picked up both the tumbler and her jaw off the floor at the end of it all.

The Submersives, they're a-workin'

 

[Mayank Shah]

Admirable work. A visit is called for soon.

 

[liverpool_for_life]

Admirable work. A visit is called for soon.

Thanks, Mayank. Hopefully, the next time you're in town!

 

[Mayank Shah]

Thanks, Mayank. Hopefully, the next time you're in town!

Really wanted to meet, but something or the other came up. Hoping for a longish break next. Will surely meet up.

 

[RajithKumar]

I'm curious to have demo of your system...will be better with Quad sub setup..

 

[liverpool_for_life]

I'm curious to have demo of your system...will be better with Quad sub setup..

Sure, Rajith. The expectation certainly is that things will be better with the addition of the pair of JS-12's. As soon as I have them in my home. I've been saying that for a while now though

 

[liverpool_for_life]

Lucky to have atleast 10ft at the rear to run diffusers

Not quite 10 feet (8), but I agree. I'm glad I have that much space at the back to be able to run diffusers effectively.

 

[liverpool_for_life]

1000 words needed please

Okay, so had the chance to ask some more questions about this. Especially as it's been indicated that more of them will be needed on the side walls.

These are effectively "diff-sorbers". The smaller ones will diffuse frequencies above 1KHz, while the larger ones will diffuse frequencies above 500 Hz. Diffusion has the advantage over absorption, of course, in that all of the acoustical energy is retained within the room. So, the room doesn't run the risk of sounding dead. The diffuse nature of the sound makes the room sound bigger than it actually is, an effect that was obvious to my untrained ears when they were first installed. Ears are used to this effect by now, so it doesn't wow me as much as it did as first

Diffusion also helps with reducing the perceived harshness, an effect that it shares in common with absorption. If I want to increase the effectiveness of the diffusion, I'm looking at polys with an 18 in dia. I'm tempted. Sorely

 

[liverpool_for_life]

So, my other acoustician (my friend and him work together) came home the other day for an evaluation of the system in my room a couple of days back.

5.1 setup for movies and 2.1 for music.

HT test scene: The opening scene from 'The Dark Knight'.

Music test track: Jacob Collier on NPR

Summary:
-----------
Now sounds decent for HT, more work to do for music (vocals weren't natural on that track, soundstage width signficantly impacted by side wall reflections etc). Much more natural sounding without any EQ applied , although resonant peaks are audible. Best to restrict EQ to 250 Hz (I was applying EQ out to 5K).

Much, much better than when the speakers first landed here 2 years ago and were placed in a bare room, but I knew that one already

Recommendations for what's left to do:
-------------------------------------------

4 of the big diffusers on each of the side walls, a pair of additional panels on the ceiling or an additional carpet, 6 inches of absorption right across the front wall and a pair of corner traps on the front wall straddling the ceiling.

I'm still balking at the side wall treatment because of the amount of real estate it'll take away. Unfortunately, the alternative recommendation of 4 inches of absorption on the side walls, will help the soundstage, but risks making the room sound dead. So, we'll do the front wall front first and then I'll re-evaluate.

So excited as this gets to a close!

 

[elangoas]

Much more natural sounding without any EQ applied , although resonant peaks are audible.

Great.. I too like it without EQ..

Best to restrict EQ to 250 Hz (I was applying EQ out to 5K).

I had the same thinking that If the room resonates only till the transition freq, why apply EQ to the range above that..

 

[mpw]

If u can do

So, my other acoustician (my friend and him work together) came home the other day for an evaluation of the system in my room a couple of days back.

5.1 setup for movies and 2.1 for music.

HT test scene: The opening scene from 'The Dark Knight'.

Music test track: Jacob Collier on NPR

Summary:
-----------
Now sounds decent for HT, more work to do for music (vocals weren't natural on that track, soundstage width signficantly impacted by side wall reflections etc). Much more natural sounding without any EQ applied , although resonant peaks are audible. Best to restrict EQ to 250 Hz (I was applying EQ out to 5K).

Much, much better than when the speakers first landed here 2 years ago and were placed in a bare room, but I knew that one already

Recommendations for what's left to do:
-------------------------------------------

4 of the big diffusers on each of the side walls, a pair of additional panels on the ceiling or an additional carpet, 6 inches of absorption right across the front wall and a pair of corner traps on the front wall straddling the ceiling.

I'm still balking at the side wall treatment because of the amount of real estate it'll take away. Unfortunately, the alternative recommendation of 4 inches of absorption on the side walls, will help the soundstage, but risks making the room sound dead. So, we'll do the front wall front first and then I'll re-evaluate.

So excited as this gets to a close!

Front wall first I think

Try 8 inch absorbers on front wall.

Of course space permitting..

It's only 2 inches more