After being radically inspired by X’s design, the XSD, I began looking at ways to lightly tweak the build and appearance. I set out and ordered the 16 woofers and started running them in in my garage while I waited for the weather to improve so I could start the woofer base slot build…..MDF is terrible stuff and has been banned from the workshop unless cut outside.
So I checked on the drivers again and the measured FS is still much higher than the spec. When manually exercising the cone and surround it’s apparent that these are just really stiff little pistons. I’ve been at this sport for a few decades now and for all the cost value savings and the design complexity….well…..I just can’t see using them for a home hifi application. Yes, the slot will attenuate the distortion but nothing can account for the slug like operation. These will be repurposed for something else….too expensive to ship them back and not a lot invested to begin with…….a pair of box loaded bass arrays for the garage/workshop maybe…..who knows.
On to the topic……X’s design XO obviously won’t work with a different woofer so I’m going to have to build on his excellent platform and take what experience I can to move in my own direction. DSP will have to be the end solution here. In keeping with sizing of the XSD, I’m fortunate to have a little more baffle width to play with so the change will start with 4 12” woofers instead of 8 6.5s. Overall height is maintained with a slightly wider and deeper baffle. Cost goes up though overall……but so does bass extension and efficiency using these
https://www.parts-express.com/Dayton-Audio-SD315A-88-12-DVC-Subwoofer-295-488?quantity=1
4 in series/parallel will result in close to 98db 2.83 so a very easy bass array to drive.
So I checked on the drivers again and the measured FS is still much higher than the spec. When manually exercising the cone and surround it’s apparent that these are just really stiff little pistons. I’ve been at this sport for a few decades now and for all the cost value savings and the design complexity….well…..I just can’t see using them for a home hifi application. Yes, the slot will attenuate the distortion but nothing can account for the slug like operation. These will be repurposed for something else….too expensive to ship them back and not a lot invested to begin with…….a pair of box loaded bass arrays for the garage/workshop maybe…..who knows.
On to the topic……X’s design XO obviously won’t work with a different woofer so I’m going to have to build on his excellent platform and take what experience I can to move in my own direction. DSP will have to be the end solution here. In keeping with sizing of the XSD, I’m fortunate to have a little more baffle width to play with so the change will start with 4 12” woofers instead of 8 6.5s. Overall height is maintained with a slightly wider and deeper baffle. Cost goes up though overall……but so does bass extension and efficiency using these
https://www.parts-express.com/Dayton-Audio-SD315A-88-12-DVC-Subwoofer-295-488?quantity=1
4 in series/parallel will result in close to 98db 2.83 so a very easy bass array to drive.
IME to be expected. What are you using to measure?
Mayhem, did i see on another thread that you suggested a SLOB increases sensitivity?
dave
I believe the actual measurements show a gain in sensitivity near field, but farfield the it would be the same as if they were not slot loaded.
dave
dave
Hi Mayhem,
You are pre-judging a driver by its ugly and cheap looks. If you want to use 16 high priced premium drivers, I’m sure it can be done. What I have here is a way to use 8x budget drivers, and since we need 8 of them per speaker - it’s not easy to fork out $160 for a typical “decent” woofer like a Satori. $2500 for 16 woofers is probably beyond the means and palatibility of many DIYers.
But the listening impressions and the measurents don’t lie. Look at the woofer’s harmonic distortion at 100Hz and 50Hz - this is 2.0Vrms so about 86dB at 1m (nominally 92dB at 1m and 2.83vrms). It’s measuring -55dB and -42dB harmonic distortion. Thats well under 1%. Not too many bass modules can do that clean of a performance as an OB. I think the cost all in with shipping was $210 for 16 of them. The surrounds do need a few days of breaking in. They sound dull at first but really become lively and deep after maybe 48hrs of moderate play time.
You are pre-judging a driver by its ugly and cheap looks. If you want to use 16 high priced premium drivers, I’m sure it can be done. What I have here is a way to use 8x budget drivers, and since we need 8 of them per speaker - it’s not easy to fork out $160 for a typical “decent” woofer like a Satori. $2500 for 16 woofers is probably beyond the means and palatibility of many DIYers.
But the listening impressions and the measurents don’t lie. Look at the woofer’s harmonic distortion at 100Hz and 50Hz - this is 2.0Vrms so about 86dB at 1m (nominally 92dB at 1m and 2.83vrms). It’s measuring -55dB and -42dB harmonic distortion. Thats well under 1%. Not too many bass modules can do that clean of a performance as an OB. I think the cost all in with shipping was $210 for 16 of them. The surrounds do need a few days of breaking in. They sound dull at first but really become lively and deep after maybe 48hrs of moderate play time.
