Hello all.
I have spent some time "ghosting" and learning a lot from the forum and I'd like to ask a question.
I want to simulate free field conditions but don't have access to an anechoic room. I've made a box which I've lined with 25 cm thick foams. When I do a chirp test I basically see nothing after 5ms. Do you think that would be ok to say that we have free field conditions? What other tests would you suggest to doublecheck the sound field in the box?
I'm using the Clio Pocket to do the measurement and I have the Auratone 5C studio monitors in the chamber. Let me know if you need any more information and i can provide.
Thank you very much for your time.
I have spent some time "ghosting" and learning a lot from the forum and I'd like to ask a question.
I want to simulate free field conditions but don't have access to an anechoic room. I've made a box which I've lined with 25 cm thick foams. When I do a chirp test I basically see nothing after 5ms. Do you think that would be ok to say that we have free field conditions? What other tests would you suggest to doublecheck the sound field in the box?
I'm using the Clio Pocket to do the measurement and I have the Auratone 5C studio monitors in the chamber. Let me know if you need any more information and i can provide.
Thank you very much for your time.
The Internal dimensions are 1000mm X 800mm X 600mm.
It's 25CM so 250mm thickness of foam overall. Sorry for the mixup.
The resulting usable space is much smaller than the box shows but it's all I need for now! [=
Thanks both for your replies
Interesting. Thanks for your reply. Is there possibly a test I can do to verify the frequencies the box works.
After reading your first post again I gather you want to do reflection free measurements by putting the speaker and mic into another large box which is lined with absorption.
May I instead suggest that you do them out in your room. Put them in the middle away from walls. Estimate and then look for the reflections in the measurements, cut them there and accept the available lower frequency resolution.
You can use other methods to assess the bass.
May I instead suggest that you do them out in your room. Put them in the middle away from walls. Estimate and then look for the reflections in the measurements, cut them there and accept the available lower frequency resolution.
You can use other methods to assess the bass.
you're probably not gonna get good mesurements with this approach. you are relying on the walls absorbing 100%! very hard....
previous post about mesurement truncation is correct. if you mesure in a tool like REW then you 'window' the mesurement so that you 100% remove all reflections. no need for any special conditions. This is called a pseudo-anechoic mesurement
Impulse Graph
previous post about mesurement truncation is correct. if you mesure in a tool like REW then you 'window' the mesurement so that you 100% remove all reflections. no need for any special conditions. This is called a pseudo-anechoic mesurement
Impulse Graph