Skip to main content
search
0
Register | Lost password?
sp_Search
Advanced Search
Advanced Search
Forum Scope


Match



Forum Options



Minimum search word length is 3 characters - maximum search word length is 84 characters
sp_Search

Please confirm you want to mark all posts read

Mark all topics read

sp_MobileMenu Actions
Avatar
Guest
Not logged in

New/Updated Topics

Select Forum

sp_TopicIcon
What Frequency Range Should I Diffuse ?
sp_Feed
Avatar
Posts: 1
April 4, 2019 - 4:50 pm

1

Hi, I have made several spectral measurements in my mixing room and I have noticed the same problem. I Have a dip from 600hz to 2khz ranging from -1db to -4db. Should I make my diffusers in that range so I can reinforce those attenuated frequency’s by diffusing them? Let’s say i’m going to make a QRD diffuser that diffuses 700hz and cuts off at 2000hz. does it seem right ?

thank you for your videos !

Avatar
Posts: 644
April 6, 2019 - 11:17 am
sp_UserWebsite sp_LinkedIn sp_GooglePlus

2

N,

Diffusion will not assist you with peaks and troughs in frequency response. It will actually make them worse. You must use broadband absorption to treat the issues.

Avatar
Posts: 6
January 13, 2020 - 1:14 pm

3

Dennis,

Are you sure about this? It seems to me that nadeau777 was on the right path with his suggestion.

As far as i know, the very main purpose of phase grating is to keep the energy within the room without disturbing the frequency response, by spreading the energy out in time.

Avatar
Posts: 644
January 15, 2020 - 10:14 am
sp_UserWebsite sp_LinkedIn sp_GooglePlus

4

S, Diffusers can not add anything to the room response other than higher Rt-60 times.

Avatar
Posts: 6
January 17, 2020 - 11:02 am

5

I will have to respectfully disagree with you there Dennis. Specular reflection from one plane will cause peaks and dips in the frequency response, because all the energy will arrive with a specific time delay in respect to the source. Depending on this time delay, some frequencies will cause destructive and some will cause constructive interference, causing peaks and dips.

A properly designed and built QRD will spread that same energy out in time, this will create a more even interference-pattern. There will no longer be certain frequencies where all the reflected energy has a perfect 180deg phase shift caused by a single time delay.

Avatar
Posts: 8
November 11, 2021 - 11:37 am

6

Hi Skogs, so is the diffuser phase shifting the troublesome frequencies/band so they are “uncancelled”? Just trying to get my head around Nadeau777’s problem.

Avatar
Posts: 644
November 11, 2021 - 12:52 pm
sp_UserWebsite sp_LinkedIn sp_GooglePlus

7

What is the issue?

Forum Timezone:
America/Los_Angeles
Most Users Ever Online: 244
Currently Online:
Guest(s) 8
Currently Browsing this Page:
1 Guest(s)

Devices in use: Phone (5), Desktop (3)

Forum Stats:
Groups: 4
Forums: 10
Topics: 631
Posts: 1690
Member Stats:
Guest Posters: 31
Members: 19369
Moderators: 0
Admins: 2
Close Menu