Speaker Impedance measurement ,circuit and sound card output

[Bernard]

icbcodc, I would rather stop measuring.
We don't have Claus Futtrup's experience (do we ?) nor the professional equipment he has at his disposal, as this is his job. Also, we don't have any large diameter woofer specimens in the Speakerbench database to compare. And as John once said, (sic) models have limitations.
If you follow JL Audio's recommendations for the size of the enclosure, you should have no problems with your speaker.
But if you want to continue, you need to report the errors returned by Speakerbench when you want to export your zma files.
Cheers.

 

[icbcodc]

icbcodc, I would rather stop measuring.
We don't have Claus Futtrup's experience (do we ?) nor the professional equipment he has at his disposal, as this is his job. Also, we don't have any large diameter woofer specimens in the Speakerbench database to compare. And as John once said, (sic) models have limitations.
If you follow JL Audio's recommendations for the size of the enclosure, you should have no problems with your speaker.
But if you want to continue, you need to report the errors returned by Speakerbench when you want to export your zma files.
Cheers.

Yes, I've ordered a 33L close enclosure for this subwoofer, 33L is very colse to the number of JL's recommendation.

And I also tried to do different simulations in VuituixCAD2 using different data measured, in my opinion, the difference in SPL curve is not that big.

I just suspect the structure of this subwoofer does not suit for dual added mass method, cause mass are fixed on the dust cap, not the real cone, and in the space among the dust cap and the cone,some air is sealed, like a spring.

 

[Bernard]

icbcodc, you have a message from Claus :

' I follow the thread on AVNirvana and I see it stopped Tuesday with the comment from icbcodc: I just suspect the structure of this subwoofer does ont suit for dual added mass method, cause mass are fixed on the dust cap, not the real cone, and in the space among the dust cap and the cone, some air is sealed, like a spring.

I believe the conclusion by icbcodc is correct. '

 

[icbcodc]

icbcodc, you have a message from Claus :

' I follow the thread on AVNirvana and I see it stopped Tuesday with the comment from icbcodc: I just suspect the structure of this subwoofer does ont suit for dual added mass method, cause mass are fixed on the dust cap, not the real cone, and in the space among the dust cap and the cone, some air is sealed, like a spring.

I believe the conclusion by icbcodc is correct. '

Thank you, Bernard

So we have to follow the T/S parameters and size of box provieded by JL audio.

I've put the subwoofer into a 31L sealed enclosure, it saves more space, and the transient performance is better than the enclosure with a slot.

 

[sm52]

icbcodc
can you post the measurement of the old and new box? It is interesting to compare. Not for T / S parameters, but normal measurement.

 

[icbcodc]

icbcodc
can you post the measurement of the old and new box? It is interesting to compare. Not for T / S parameters, but normal measurement.

Hello

FYI.

DSP SETTINGS

LP: 70HZ for sealed enclosure, around 53hz FOR bass reflex enclosure
LP Filter: Butterworth -12dB
HP:23hz

Measured at different time and level with the same amplifer and the same positioin(at the driver's seat).

 

[sm52]

If the red graph is a closed box, then the bass plays better. But there is a high level of distortion.

 

[icbcodc]

If the red graph is a closed box, then the bass plays better. But there is a high level of distortion.

Yes,but I don't know what causes that distortion.

 

[sm52]

It can be reflections inside the box. Or the amplifier does not control this speaker well. Other reasons are also possible.