# EQing above the Schroeder Frequency



## jtalden

lashlee,
Per your post Here I can only make a few extra comments as I do not really understand all the ins and outs of EQ. I do have an idea on some basics.

Basics:
> The Schroeder frequency is normally considered to be in the 200-300 Hz range for small rooms. It is the upper frequency that room modes prevail. A car might not have a Schroeder frequency as the size is too small?
> EQ can be effective in the modal frequency range, but it very much depends on the actual room setup. It is also limited to a relatively small regions around the LP as any boost or cut to improve the response there will have a detrimental impact in some other parts of the room. There is no way to fix the room using any type of EQ, but we can often improve the situation around the LP area.
> It is considered far better to address as much of the issues as possible with speaker and LP positioning and room treatments before EQ is applied.
> EQ can be detrimental if large or sharp PEQ filters are used. In moderation they work fine.
> Again in normal rooms and assuming the speaker response is designed to be smooth and flat, the frequencies greater than maybe 600 Hz should not be EQ'ed except to possibly broadly shift the response to a preferred house curve. 
> The frequencies from 300-600 Hz are also normally addressed with LP/speaker positions and acoustic treatments. It is unclear to me if and how much EQ can help. I see most all experts seeming to dislike using EQ in that range, but there are lots of automated EQ packages that do just that and receive great reviews. Experimentation in my room is not conclusive. 

That is about all I can say with any reasonable confidence. I have no experience with auto applications. There is lots of info to be found here with a search and also on the web.


----------



## AudiocRaver

Thanks for the nice summary, John.


----------



## Owen Bartley

I see that the ability to select a point around the Scroeder Frequency (or anywhere, I think) is a feature of the new Audyssey App, and it will allow you to cut off where Audyssey will make changes to your sound. I haven't tried it myself, but it seems like a great idea, especially for people who have the ability to treat their rooms effectively with absorption/diffusion panels.


----------

