The Purezza is a different design with a different PR and a not very flat low frequency response.
He hasnt properly corrected the baffle step or possibly got the box volume wrong. If he had the SPL at 300Hz and above would be about 4 dB lower, hence you would need to apply a lot more power (twice as much) to achieve 97dB and you would have more relative distortion.
Jason Kwrote:
That was nearfield measurement of woofer. In front of the woofer 1cm. They looks clean enough. But when the reviewer measured in front of PR, the problem was showed like 1M measurement.
When I saw them, I thought the distortion is occured to back of the woofer. Not in front of it. If this assuming is right, speaker driver test can be explained(clean) and additional absorber in the Sointuva reducing distortion can be explained too.
Jason Kwrote:
That was nearfield measurement of woofer. In front of the woofer 1cm. They looks clean enough. But when the reviewer measured in front of PR, the problem was showed like 1M measurement.
Jason Kwrote:
When I saw them, I thought the distortion is occured to back of the woofer. Not in front of it. If this assuming is right, speaker driver test can be explained(clean) and additional absorber in the Sointuva reducing distortion can be explained too.
Yes, I agree. if you completely filled the speaker with sand you could probably block it further 😉 but that would spoil the box tuning/compresion.. Did you see the impedance responses after he filled the speaker with more stuffing?
Alan Marchwrote:
Yes, I agree. if you completely filled the speaker with sand you could probably block it further 😉 but that would spoil the box tuning/compresion.. Did you see the impedance responses after he filled the speaker with more stuffing?
I saw them. Impedance peaks are reduced and bass response is shelved. Not good sign as passive speaker.. but reduced the distortion.
If the magnet - frame resonance is the main reason, how about adding damping sheet on the frame or adding pressure on the back(magnet). To be pressed by hard stuff when assmble the woofer.
Jason Kwrote:
I saw them. Impedance peaks are reduced and bass response is shelved. Not good sign as passive speaker.. but reduced the distortion.
If the magnet - frame resonance is the main reason, how about adding damping sheet on the frame or adding pressure on the back(magnet). To be pressed by hard stuff when assmble the woofer.
we have already looked at various options along these lines
Alan Marchwrote:
The Purezza is a different design with a different PR and a not very flat low frequency response.
He hasnt properly corrected the baffle step or possibly got the box volume wrong. If he had the SPL at 300Hz and above would be about 4 dB lower, hence you would need to apply a lot more power (twice as much) to achieve 97dB and you would have more relative distortion.
57
But 97 to 85dB is more important.
It is not 3~4dB diffrence.
Sample A 85dB distortion level similar Selah’s 97dB.
Is it randomable distortion that we just should accept?
Jason Kwrote:
But 97 to 85dB is more important.
It is not 3~4dB diffrence.
Sample A 85dB distortion level similar Selah’s 97dB.
Is it randomable distortion that we just should accept?
yep, see my point about power
the baffle step is wrong. If corrected twice as much power is required to achieve the same output. Thios will make the Purezza distort more. Remember crossovers also distort.
