svs pb 2000 pro having null in small room

hardcore_gamer99 · Nov 1, 2024

Hello all. My room size is
height 10 feet length 12.75 feet width 10.3 feet. I tried subwoofer crawl 4times but the thing is when subwoofer is in chair then bass is good while i crawl and find good place but after actually putting it in the place its not same. I tried a lot but no, Now i have finally bought UMIK-1 MIC and would like to have your pro help . I have pc with windows 10 and will connect my denon x4800h through hdmi. I ran bass loop on youtube so the thing is in frequency range 70 to 80hz there is NULL. So how can REW help me? I dont know about rew anything yet. So how do i start from scratch? I want to put my subwoofer its heavy onlly in front and i can try 2 or 3 positions max only. I have dali opticon 2 mk2 as fronts. Should i use lfe only or lfe+mains? speaker crossover? While connecting denon with pc should i use hdmi output slot or hdmi in

FargateOne · Nov 1, 2024

hardcore_gamer99 said:
So how do i start from scratch?

First tell us what you know about acoustics, bass responses in confine environment such as home theater, show us screen shuts of your measurements. Null are part of all bass and mid bass frequencies and directly related with boundaries lenght in your room. Physics have laws and null will always there wherever you put a sub.

JStewart · Nov 1, 2024

In addition to @FargateOne ’s question…

hardcore_gamer99 said:
I tried subwoofer crawl 4times but the thing is when subwoofer is in chair then bass is good while i crawl and find good place but after actually putting it in the place its not same.

Even a small difference of inches can make a difference in the measured response.

hardcore_gamer99 said:
So how can REW help me?

With one sub and one listening position then with trial and error it can show the best positions within your constraints.

hardcore_gamer99 said:
I dont know about rew anything yet. So how do i start from scratch?

REW’s author has some getting started links here:
Thread 'Some guides to REW and acoustic measurement'
https://www.avnirvana.com/threads/some-guides-to-rew-and-acoustic-measurement.121/

hardcore_gamer99 said:
I want to put my subwoofer its heavy onlly in front and i can try 2 or 3 positions max only.

Then those are the positions to measure.

hardcore_gamer99 said:
I have dali opticon 2 mk2 as fronts. Should i use lfe only or lfe+mains? speaker crossover?

Only your ears subjectively or measurements objectively, can determine.
You have Audyssey on the Denon. Is there a reason you don’t wish to use it?

hardcore_gamer99 said:
While connecting denon with pc should i use hdmi output slot or hdmi in

pc hdmi out to dennon hdmi in.

hardcore_gamer99 · Nov 1, 2024

FargateOne said:
First tell us what you know about acoustics, bass responses in confine environment such as home theater, show us screen shuts of your measurements. Null are part of all bass and mid bass frequencies and directly related with boundaries lenght in your room. Physics have laws and null will always there wherever you put a sub.

i am newbie and know nothing about acoustics home theatre. i am sitting 90 inches from tv unit. my room is normal bedroom and has 1 window 1 inwall wardrobe and 2 gates to the left right of my tv unit here is the video

Wayne A. Pflughaupt · Nov 1, 2024

Small rooms like this are always a problem, bass-speaking. They’re also pretty predictable, so there’s no reason to do a sub-crawl.

The physics is, bass in any room is strongest at room boundaries, and it strongest at room junctions (aka corners). Perceived bass intensity decreases as you move from a corner towards the next boundary (up, down, right or left), or from there towards the center of the room. This situation will be more pronounced in a small room vs. a large one. In a small room, movement in any direction, even a foot or so, can result in audible differences.

This phenomenon is easily replicated by anyone with a SPL meter set for C weighting, and a broadband pink noise source: The meter reading will drop the further you move away from a corner, with the lowest reading being dead center of the room (i.e. a bit below head level).

The picture below gives an idea of the situation, the red zone being bass intensity. (The picture isn’t totally accurate, as the front and back walls should also show reduced “red” at the center of the wall, as well as at the ceiling level).

The worst location for the sub will be dead-center on a wall. The go-to recommendation is put the sub either in a corner, or no more than 1/4 wall length from the corner. You can experiment further from there.

You’ll get the best perceived pass levels with the listening position against a wall. That may not be optimal for stereo imaging, however. You can move the listening position forward for better overall results, but the closer to center-of-room you get, the more bass levels will be reduced.

Basically, it’s all a compromise. You have to determine what works best for you.

Regarding the issue at 70-80 Hz, it’s most likely because you have a nasty peak in frequency response in the lower frequencies, to the point that everything else is being swamped. REW can show you where the peak is, and parametric EQ can tame it. Then the sub should sound normal. The exception might be the unusual sub that doesn’t have enough output at the top end.

ordpress%2F2015%2F02%2FPressure-distribution-model.png

Regards,
Wayne

hardcore_gamer99 · Nov 2, 2024

Wayne A. Pflughaupt said:
Small rooms like this are always a problem, bass-speaking. They’re also pretty predictable, so there’s no reason to do a sub-crawl.

The physics is, bass in any room is strongest at room boundaries, and it strongest at room junctions (aka corners). Perceived bass intensity decreases as you move from a corner towards the next boundary (up, down, right or left), or from there towards the center of the room. This situation will be more pronounced in a small room vs. a large one. In a small room, movement in any direction, even a foot or so, can result in audible differences.

This phenomenon is easily replicated by anyone with a SPL meter set for C weighting, and a broadband pink noise source: The meter reading will drop the further you move away from a corner, with the lowest reading being dead center of the room (i.e. a bit below head level).

The picture below gives an idea of the situation, the red zone being bass intensity. (The picture isn’t totally accurate, as the front and back walls should also show reduced “red” at the center of the wall, as well as at the ceiling level).

The worst location for the sub will be dead-center on a wall. The go-to recommendation is put the sub either in a corner, or no more than 1/4 wall length from the corner. You can experiment further from there.

You’ll get the best perceived pass levels with the listening position against a wall. That may not be optimal for stereo imaging, however. You can move the listening position forward for better overall results, but the closer to center-of-room you get, the more bass levels will be reduced.

Basically, it’s all a compromise. You have to determine what works best for you.

Regarding the issue at 70-80 Hz, it’s most likely because you have a nasty peak in frequency response in the lower frequencies, to the point that everything else is being swamped. REW can show you where the peak is, and parametric EQ can tame it. Then the sub should sound normal. The exception might be the unusual sub that doesn’t have enough output at the top end.

View attachment 75142

Regards,
Wayne

should i also not sit in middle of back wall and also few inches away? how do i calibrate subwoofer in REW

hardcore_gamer99 · Nov 2, 2024

for gods sake can someone help me how do i setup preferences in pc windows 10 i have connected denon through hdmi from my graphic card. asio4all is not working in pc when i load it it crashes the software and closes

JStewart · Nov 2, 2024

hardcore_gamer99 said:
for gods sake can someone help me how do i setup preferences in pc windows 10 i have connected denon through hdmi from my graphic card. asio4all is not working in pc when i load it it crashes the software and closes

Instead of trying to troubleshoot ASIO, why not use the Java drivers that start with EXCL?

hardcore_gamer99 said:
how do i calibrate subwoofer in REW

To be clear, REW is a system to measure and analyze. It can create EQ filters that can then be used by a device in the playback chain. The filters are created based on the measurement and target that are used.

So to your question then... Learning how to use REW and understanding how, when, and why or why not to EQ can be daunting. I expect for many of us here this is a journey and not a destination. Some reading and patience is required, but it gets rewarded.

@Wayne A. Pflughaupt has written excellent articles on selecting and using “house curves”, which are equalization target, here:

House curve: What it is, why you need it, how to do it!

www.hometheatershack.com

I asked this question before and am still curious, have you tried using the Audyssey auto room EQ functionality on the Denon? A great many have started with this and then learned to measure and tweak, if desired, afterward.

jeppekristoffer · Nov 3, 2024

In what country do you live? Or more important, what time zone? If you are not that far of off sweden i can help you over phone.

hardcore_gamer99 · Nov 3, 2024

jeppekristoffer said:
In what country do you live? Or more important, what time zone? If you are not that far of off sweden i can help you over phone.

india

also it showed this. what to do?

jeppekristoffer · Nov 4, 2024

hardcore_gamer99 said:
india also it showed this. what to do?

That means that you forst have to make shure that the noise(people shattering, tvs, radios, street noise, neighbours) is quiet. Basically as little surrounding noise as possible. Then try again. If you get the same warning then increase the level to the speaker by lets say 3 dB. Try again.

jeppekristoffer · Nov 4, 2024

And as others have said. It takes some time to learn. I started in 2018 but i also have a masters degree in engineering acoustics.

FargateOne · Nov 4, 2024

hardcore_gamer99 said:
india also it showed this. what to do?

It is a good thing to ask for help and you will have a lot in this forum. Barrier language forbide me to help you. But it is also a good thing to read. John help index is a condensed teaching of all basics in acoustics . I began to read in 2015 and now I can tell and proove to Dirac that something is broken is ther DLBC software. And I am not Einstein, so ther is hope!
Sound to noise ratio is one of the basic principle to you need to understand among many others.

hardcore_gamer99 · Nov 4, 2024

FargateOne said:
It is a good thing to ask for help and you will have a lot in this forum. Barrier language forbide me to help you. But it is also a good thing to read. John help index is a condensed teaching of all basics in acoustics . I began to read in 2015 and now I can tell and proove to Dirac that something is broken is ther DLBC software. And I am not Einstein, so ther is hope!
Sound to noise ratio is one of the basic principle to you need to understand among many others.

All i know is my untreated bedroom size is

height 10 feet length 12.75 feet width 10.3 feet
There is tv unit and my tv is on it and have dali opticon 2 fronts here to left and right of tv unit and there are gates on both sides of tv unit and i sit on opoosite wall which has inwall small wardrobe to my right side. left side wall is concrete wall. Also there is window on right wall where i sit just near right gate. And i put my subwoofer here now can you tell how doo i start treating my room acoustics? what to do add first? this is video of my room

svs pb 2000 pro having null in small room

hardcore_gamer99

New Member

FargateOne

Member

JStewart

Senior AV Addict

hardcore_gamer99

New Member

Attachments

Wayne A. Pflughaupt

Moderator

hardcore_gamer99

New Member

hardcore_gamer99

New Member

JStewart

Senior AV Addict

House curve: What it is, why you need it, how to do it!

jeppekristoffer

New Member

hardcore_gamer99

New Member

Attachments

jeppekristoffer

New Member

jeppekristoffer

New Member

FargateOne

Member

hardcore_gamer99

New Member

Popular tags

OUR MISSION

Quick Navigation

Buy us a cup of coffee!