@saikatbiswas82 , it's a pine wood frame.
@Fiftyfifty , agree that in practice there can be an imbalance and it will depend on the speakers and the room. Won't hurt to have thick drapes.
@SwaroopKS /
@jenson the Maargas themselves are excellent speakers. My expectations of an upgrade was to get closer to a live performance. The OBs are a step in that direction. They live up to their expectation - nice bass, non-boxy and room filling sound. They really shine on well mastered tracks. Vocal Jazz is outstanding. Overall the OBs are more "fun" to listen to and offer exceptional bang for buck. Unfortunately poor recordings sound bad. Many old Bollywood tracks sound pale unless they were mastered well. The Maargas are more a bit tolerating of recording quality.
The FR did make a difference. I tried the FaitalPro and Mark Audio before switching to Tang Band 1808. Up the chain the FRs get expensive (Jordan Eikona, Voxativ, AER) but I got mixed comments from members on diyAudio in terms of VFM.
There are a few challenges with the OB for someone who wants to venture down this path. The construction of this kind of FAST/WAW (Fullrange Assisted Subwoofer Technology/Wideband Assisted Woofers) itself is quite simple but there are some tradeoffs arising with crossover/EQ and amplification. You can
- feed the full signal to the FR and parallel that to a plate amp for the woofers. Matching could be tricky as you're not really crossing over since the FR is always playing. So there may be a boost in the range where both are playing and FR hasn't rolled off sufficiently.
- use a passive crossover. But with this you can't boost the bass rolloff with OB.
- use a DSP. I chose this because it allows you to try different crossover points, EQ and I could do a bit of bass boost. This adds to the cost and I had to use it's built-in DAC (which may not be to your liking). There are multi-channel Amps and DACs but then that'll get expensive.
Also, except for the passive solution you will need 2 amplifiers one for the FR and one for the woofers. So more equipment and increased costs. To me the DSP was worth it because I was able to measure and correct even for room issues.
The next step is to try a multi-driver OB. Initially I thought OB simply meant mounting drivers on flat baffles. But as I read through the theory I realised that Linkwitz and others propose that constant directivity speakers like dipoles (
https://www.linkwitzlab.com/Constant_directivity_louds.htm) sound better.
An ideal dipole needs to have identical forward and rearward radiation. Typical drivers have cones in front and the magnet and basket assembly at the back. So the rear radiation is not identical to the front. The problem is not so severe for large woofers because the magnet area is smaller compared to the overall driver dimensions. Tweeters pose bigger challenge. To tackle this people try tweeters (facing front and back) or dipole drivers like dipole ribbons.
The other issue for dipoles is that a certain relationship between the driver radius and wavelength must be maintained. The only way to achieve this is to make use of multiple drivers to handle separate frequency ranges. This is evident from Linkwitz's own creation, the LX-521 (
http://www.linkwitzlab.com/LX521/Description.htm ). You start with a large woofer for low freq and move to smaller and smaller drivers as you go towards the top end. The baffle is either very small or non-existent as you move up.
Ofcourse multiple drivers brings along with it more complexities in terms of driver matching, crossover design, more amps etc. There are good attempts by several members on diyaudio forum so hope to try something.
Some interesting projects..
https://www.diyaudio.com/forums/mul...aborative-speaker-project-48.html#post4231049
https://www.diyaudio.com/forums/multi-way/366380-hybrid-frame-ob-nude-driver-6.html
https://www.diyaudio.com/forums/multi-way/219344-4-dipolar-disorder.html
https://www.audiocircle.com/index.php?topic=143418.0
http://musicanddesign.speakerdesign.net/NaO_Note_II_RS_Details.html
https://www.baffless.com/
https://www.hifizine.com/2010/12/prototyping-4-way-open-baffle-speaker-with-the-minidsp-2x4/
https://www.diyaudio.com/forums/att...nt-directivity-baffle-baffle-save_image-4-jpg
