Happy new year to you all
I am in the planning of my first dipole speaker project. As part of the project, I am considering building stereo dipole subwoofers. The design goals are to obtain a well controlled bass with a system Q of around 0.5-0.7 that can reach 30-35Hz at a reasonable spl (of course WAF will be close to 0). The design I have in mind is similar to the design of Stig Erik:
http://www.diyaudio.com/forums/multi-way/142015-my-open-baffle-dipole-beyma-tpl-150-a-103.html
In this design, I will have 2x18” (or 2x21”) per side in H-baffles. I intend to xo to a 15” midbass, also in a open baffle construction. As a starting point, I think the xo frequency should be somewhere around 80-100 Hz. For the sake of flexibility, it is desirable if the subs can extend to 150-200Hz if needed. I intend to xo actively with eq.
At this moment, I am considering a handful of different pro drivers for the subs:
1) Beyma 21SW1600Nd (21”, the same as Stig Erik is using).
http://profesional.beyma.com/ingles/pdf/21SW1600Nd.pdf
2) The new Beyma 18LX60V2 (18”)
http://profesional.beyma.com/ingles/pdf/18LX60V2.pdf
3) BMS 18n840 or 18n860 (18”)
http://bmsspeakers.com/index.php?id=neodymium_cone_drivers
The 21SW1600Nd has the advantage of being large (large sd) with a healthy xmax of 15mm. The 18LX60V2 generally seems to fit the bill quite well with a Qt close to 0.5 and fs at 35Hz. This driver has an ok xmax ok 9mm. The BMS drivers look pretty awesome too with their low distortion design. However, the BMS drivers are less efficient and their specs. may be less suitable for this application. In addition, the BMS drivers are considerably more expensive than the Beyma drivers. Especially, the 18LX60V2 comes at a very favorable price compared to the rest of the pack.
At this point, I am leaning towards the Beyma 18LX60V2 as the best compromise.
I would highly appreciate any comments, experience and (or) recommendations you may offer. What are the key factors to consider when designing a dipole subwoofer? Another issue is, how important is inductance when it comes to SQ? The Beymas typically have higher inductance compared to many other drivers out there.
Cheers David
I am in the planning of my first dipole speaker project. As part of the project, I am considering building stereo dipole subwoofers. The design goals are to obtain a well controlled bass with a system Q of around 0.5-0.7 that can reach 30-35Hz at a reasonable spl (of course WAF will be close to 0). The design I have in mind is similar to the design of Stig Erik:
http://www.diyaudio.com/forums/multi-way/142015-my-open-baffle-dipole-beyma-tpl-150-a-103.html
In this design, I will have 2x18” (or 2x21”) per side in H-baffles. I intend to xo to a 15” midbass, also in a open baffle construction. As a starting point, I think the xo frequency should be somewhere around 80-100 Hz. For the sake of flexibility, it is desirable if the subs can extend to 150-200Hz if needed. I intend to xo actively with eq.
At this moment, I am considering a handful of different pro drivers for the subs:
1) Beyma 21SW1600Nd (21”, the same as Stig Erik is using).
http://profesional.beyma.com/ingles/pdf/21SW1600Nd.pdf
2) The new Beyma 18LX60V2 (18”)
http://profesional.beyma.com/ingles/pdf/18LX60V2.pdf
3) BMS 18n840 or 18n860 (18”)
http://bmsspeakers.com/index.php?id=neodymium_cone_drivers
The 21SW1600Nd has the advantage of being large (large sd) with a healthy xmax of 15mm. The 18LX60V2 generally seems to fit the bill quite well with a Qt close to 0.5 and fs at 35Hz. This driver has an ok xmax ok 9mm. The BMS drivers look pretty awesome too with their low distortion design. However, the BMS drivers are less efficient and their specs. may be less suitable for this application. In addition, the BMS drivers are considerably more expensive than the Beyma drivers. Especially, the 18LX60V2 comes at a very favorable price compared to the rest of the pack.
At this point, I am leaning towards the Beyma 18LX60V2 as the best compromise.
I would highly appreciate any comments, experience and (or) recommendations you may offer. What are the key factors to consider when designing a dipole subwoofer? Another issue is, how important is inductance when it comes to SQ? The Beymas typically have higher inductance compared to many other drivers out there.
Cheers David
One very important thing to consider is cooling, or rather the noise of it. As there is no box behind the driver to attenuate it.
I would look at B&C. I have only heard good bout their cooling.
And you can't say no to their basket design.
I would look at B&C. I have only heard good bout their cooling.
And you can't say no to their basket design.
Thanks for the reply
I had this potential problem in mind. My thought was that several large drivers will limit excursion and thereby any noise made by the drivers. I have looked at the B&C drivers. Especially their 21” driver looks good (and, yes, that basket design is very cool). Unfortunately, the price is rather high compared to the Beyma 21SW, at least here in Norway.
David
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