Home Theater Forum and Systems banner

1 - 10 of 10 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Hello, I am now ready to take measurements, but one thing makes me frustrating. Calibration SPEAKER. Why there is nothing about that in preferences of REW. Of course there is EQ and things like that, but why I cant just load calibration file for speaker?

Probably, it is important which curvatures of the resulting graphs are due to room acoustics, but which ones depends on the frequency characteristics of the speaker? How to avoid such an error when measuring? Or maybe it's not important, and I just don't understand the idea? Can you help me or explain in simply words? I'm totally new and green in REW and acoustic treatment at all.

I want to say one more thing: I have quite old speakers and I could not find frequency response graph for them. But even if I have these graph, so I could create a calibration file, but then how I can implement it to the REW?

Greetings and thanks in advance for your help.

Best Regards.
 

·
Premium Member
Joined
·
1,562 Posts
You may be reading 'Room EQ' too literally.

We normally EQ the SPL response at the LP. We are looking to achieve a target SPL response regardless of whether the source of the deviation is due to the speaker or the room. For most speakers the SPL response is reasonably good without EQ so the room is the major source of the deviations. This is particular true at low frequencies where room modes are common.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #4
Think about it: Let’s say you could obtain or generate a calibration file for your speakers and load it into REW. When you then took a measurement of your speakers it would generate a frequency response graph that was perfectly flat. Would you find that terribly useful?

Regards,
Wayne
Hello, thank you very much for your reply. But actually I can't agree (please remember I totally greenhorn).
As I understand it:
I agree that if I load speaker calibration file to REW, then measurement gives me totally flat line.
BUT ONLY if I make that measurement in the ANECHOIC chamber room. But If I make measurement in normal room (with some response) then I will receive graph of exactly freq. response of that room.
Does it make a sense?
If yes so it's good idea for the REW would give you option to load speaker cal. file.
But if it doesn't make sense, then I admit: I don't understand it and probably I give up. :)
 

·
Registered
Joined
·
8 Posts
Discussion Starter #5
You may be reading 'Room EQ' too literally.

We normally EQ the SPL response at the LP. We are looking to achieve a target SPL response regardless of whether the source of the deviation is due to the speaker or the room. For most speakers the SPL response is reasonably good without EQ so the room is the major source of the deviations. This is particular true at low frequencies where room modes are common.
OK, Now I will ask something really stupid.
Can you explain me in really simple words what is "SPL", and "LP"?
Of course I can read REW manual about SPL, and LP. But please forgive me, it's really to hard for me to go through all those complicated words and sentences. Especially if you notice English is not my first language. But with this manual I probably would have problem to understand even in my first language - Polish.
Thanks for any advices. :)
 

·
Premium Member
Joined
·
6,711 Posts
You could load a speaker anechoic response in place of the soundcard or mic calibration files.
 

·
Super Moderator
Joined
·
9,258 Posts
As I understand it:
I agree that if I load speaker calibration file to REW, then measurement gives me totally flat line.
BUT ONLY if I make that measurement in the ANECHOIC chamber room.
But If I make measurement in normal room (with some response) then I will receive graph of exactly freq. response of that room.
As JohnM noted, you could load a speaker calibration file into REW in place of the sound card or mic calibration file. I’m sure you don’t have one, as there is no such thing, but you could make a calibration file if you have a frequency response graph from the manufacturer. Assuming the manufacturer generated their graph in an anechoic room, then yes you could get a frequency response measurement of the room, if that is your objective.

So is that your objective? Are you trying to plot the frequency response of various rooms in your place to determine the best one to set up your system in?

Regards,
Wayne
 

·
Registered
Joined
·
8 Posts
Discussion Starter #10
Hello,
thank you very much for your answer, now I understand much more. Maybe it's stupid, but my room is living room, so even if I want I don't have to many options to acoustic treatments.
So actually my objective is to understand what I'm doing. Measurement is less important for me than understanding, because than I can be sure that I do everything properly and my strange measurement results, are because of my room, but not because I'm doing something wrong.
You told:
"but you could make a calibration file if you have a frequency response graph from the manufacturer"
I've made it with my microphone, and ask people on forums if it makes a sense. All people told me "it doesn't make a sense". But thanks to you, now I understand it doesn't make PRACTICAL sense. but THEORETICAL sense is OK. It satisfies for me. Thanks :)
 
1 - 10 of 10 Posts
Top