First Ported design
Hi all,
This ain't much compared to the amazing designs I've seen in this thread, but here goes:
Comments appreciated, keep in mind this is my third speaker box, the other two were much smaller (~10l), and sealed.
Hi all,
This ain't much compared to the amazing designs I've seen in this thread, but here goes:
- Woofer: Vifa TCW18
- Tweeter: Locally bought, measured with an impedance peak at 1.5kHz No calibrated mike, so I dont know the freq. response.
- Cabinet: 43l ported, tuned to ~37Hz
- Max power handling: 10.3W (as reported by WinISD)
- Crossover: 12dB/oct, at 2.7kHz, with impedance rise cancellers for woofer and tweeter.
- Total system cost: ~Rs. 7500 ($170, at current rates)
- Sound: In the words of Lil' John and the Eastside Boyz, "Get Loow!!!"
Comments appreciated, keep in mind this is my third speaker box, the other two were much smaller (~10l), and sealed.Attachments
Dipole Speaker
Hello,
at this address (in the projects folder) you can see a dipole speaker, with measurements: http://planeta.terra.com.br/educacao/claudionegro/english/
Claudio
Hello,
at this address (in the projects folder) you can see a dipole speaker, with measurements: http://planeta.terra.com.br/educacao/claudionegro/english/
Claudio
Attachments
Rudolf,
Claudio encouraged me to join this forum which I find quite inetersting and useful. So here are some comments to your question.
I did not use a baffle for the dipole for simplicity, as long as I could get a good bass response. Actually the room (and the position of the dipole and listening chair) modal response limits, I believe, how much bass I can get. Having an uncontrolled amount of bass can veil the transparency.
Nevertheless, I have not tried having a baffle and it would be interesting to hear the difference.
Regards,
Jose
Claudio encouraged me to join this forum which I find quite inetersting and useful. So here are some comments to your question.
I did not use a baffle for the dipole for simplicity, as long as I could get a good bass response. Actually the room (and the position of the dipole and listening chair) modal response limits, I believe, how much bass I can get. Having an uncontrolled amount of bass can veil the transparency.
Nevertheless, I have not tried having a baffle and it would be interesting to hear the difference.
Regards,
Jose
Hi Jose,
welcome to this great place.
Your baffle-less dipole seems to be more radical than any dipole I´ve seen here - yet carefully implemented. So I´ve got some more questions right away:
Due to the perfect round shape of the drivers there should be significant dips and notches (combing) in the FR of your dipole. I wonder how you could equalize that. Or is it no longer audible/visible in your room response? Could you give some hint, how complex your equalization with the BSR 3000 is and how much you had to compensate for the LF roll-off?
Thanks for sharing
Rudolf
welcome to this great place.
Your baffle-less dipole seems to be more radical than any dipole I´ve seen here - yet carefully implemented. So I´ve got some more questions right away:
Due to the perfect round shape of the drivers there should be significant dips and notches (combing) in the FR of your dipole. I wonder how you could equalize that. Or is it no longer audible/visible in your room response? Could you give some hint, how complex your equalization with the BSR 3000 is and how much you had to compensate for the LF roll-off?
Thanks for sharing
Rudolf
Rudolf,
Thanks for the welcoming to the site.
I am not sure why on-axis there should be significant dips and notches on the frequency response (other than those inherent to the driver or room modes) due to the circualr boundary of the driver. For one thing the sound field at the edge is in theory negligible so that diffraction effects are absent. The frequency response plots were made at about 1.37 m from the driver. As I move my head or the michropone laterally (+/- 0.15 m) I do not perceive a significant change in response. The dipole simulations in the web (Dan Russell) show a smooth field. Can you suggest a test I can perform to look up for dips and notches?
In regard to the equalizer adjustment I will make a note and send to you the position of the levers later. Though esentially all levers below 1000 Hz are near +12 db and all others near -12 db. At some point I had two equalizers in tandem to create a +/- 24 db equalizer with a steeper slope. I found that trying to compesnate for more than +/- 12 db can create noise problems. This depens on the type of driver and range one wants to compensate for.
Jose
Thanks for the welcoming to the site.
I am not sure why on-axis there should be significant dips and notches on the frequency response (other than those inherent to the driver or room modes) due to the circualr boundary of the driver. For one thing the sound field at the edge is in theory negligible so that diffraction effects are absent. The frequency response plots were made at about 1.37 m from the driver. As I move my head or the michropone laterally (+/- 0.15 m) I do not perceive a significant change in response. The dipole simulations in the web (Dan Russell) show a smooth field. Can you suggest a test I can perform to look up for dips and notches?
In regard to the equalizer adjustment I will make a note and send to you the position of the levers later. Though esentially all levers below 1000 Hz are near +12 db and all others near -12 db. At some point I had two equalizers in tandem to create a +/- 24 db equalizer with a steeper slope. I found that trying to compesnate for more than +/- 12 db can create noise problems. This depens on the type of driver and range one wants to compensate for.
Jose
