Volcano Subwoofer Cabs, design and build

I thought this was a sub for a DJ rig? 19 liters sounds like 2.1 channel computer sub territory...are we about to break physics?!
All jest aside. I walked down the stairs into quality Hi-Fi in York Street, Sydney with a bunch of Greensleeves sampler CD's. Not one item turned out to be high fidelity. Most subs couldn't render the basslines properly, and everything distorted on raising the volume a bit. Next stop, Doran Pro Audio. A JLAudio W7 in a sealed 20L just lapped it up and wanted more. Allowed the bass knob to be actually turned up. The nightclub system that I had DJ'ed on had the bass turned down as the subs would distort. Seriously, why stick with this pretence hi-fi or Pro audio when it can't play a simple proper bassline?
 
It should be noted that the low volume cab sizes as drawn are designed for Low Vas/high Xmax drivers/very high power type of drivers such as the DS18 ZXI12.4d and ZR12.4D. The cab concepts will explore if drivers that can usually be heard from a street away can be ported to domestic and live use. This cab volume is easily increased for use with regular drivers
The original; post is updated to include the quoted text. Let's take a step away from those that have problems with experimenting and exploring different concepts

I will have to get creative with the workbench subwoofer model. Some time ago, I developed a FreeCAD template for segmented TLs. That design had the ability to transform tunnel lengths and Sd during initial assembly and will suit a workbench use. Will include the ability to change baffle so drivers can be rolled

But before that, a disposable breaker box. I have quite a bit of MDF offcuts in storage. I'll draw up something that can use that to break in the driver. It would also be a proof of concept for the undersized Sd transmission line
 
Did you ever build the big underseat (couch) subwoofer? You’d instantly find all this incredibly tiny stuff in your rear view mirror (I think)👽💩💨
I did. But its only bass exciters. Need the space underneath for storage. And we cant really run much over 96db anyway due to the next house being fairly close enough to be an issue for the neighbours. This is just messings with the ZXI driver
 
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Can someone try modeling these, i am getting weird results.
I dOnt know what to use for dcRE on the bottom subwoofer?

Been working on the DS18s for a bit now in both WinISD and Hornesp as well as talking to DS18 tech. It seems to me that the measured specs are per coil but weirdly some parameters are instead listed for coils in series. Both software show this anomaly. In last coms with tech, I as told that all the drivers are now being put through breaking in and remeasuring with now datasheets to be uploaded soon

These on the site were changed not too long ago but still show the anomaly except for Xmax which has been taken out to be relisted in the next manual they said. I got the feeling that their competition lists Xmax in peak to peak and DS18 policy of listing one way placed them at a disadvantage. Example, Earthquake list 70mm for a similar driver but that's peak to peak

Dave, thats the wrong JL. The one I had was an older 15W3 series, which was like 4 tiers up from the W0. The version that came out after mine was relabelled as 13" as the roll went all the way to the frame edge. The current pick of the bunch in the JL is the one linked below. I have one in my car running off a 100wrms JLAudio amp in a 30L box tuned to 33Hz. Measured only to 127db recently due to not having emogh amp. The W7 wants 2000w

https://www.jlaudio.com/collections...ucts/12w7ae-3-car-audio-w7ae-subwoofers-92115

The DS18 ZXI12.4D looks like the driver to work with in trying to find a much more value replacement for what the JL can do but in an even smaller box

Booger
The measured Re for each coil is 4R
 
Just measure the resistence of one of its coils at the terminals real quick
 

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Would I risk damaging the driver with DC?
A standard multi-meter does not apply a constant DC voltage, it applies a very low current (typically well under a 1/1000 of an ampere) and measures the voltage across the load.

Just like AC, if you apply enough DC voltage for a sufficient length of time you can fry it's voice coil.

Continuous DC voltage holds the voice coil in one position, which does not allow air movement to cool it, so will heat it faster than AC voltage.
 
Bugger, my multimeter has a 9v battery which seems flat. I picked up a technician grade meter from Jaycar a couple of years ago, but it's been sitting around. Must admit, not really sure how to set it to measure coil Re properly. Need to learn how to use it

https://www.jaycar.com.au/economy-t...os=1&queryId=596a20d51a1add32f63bd61d1f9fb6f9

Was up working all night as the baby had kept me pretty busy all day. Slept all day. Its Sat afternoon here and a 9v battery might get tricky to find in the rurals
 
The third pic is only the alloy structure. Let's call it a 'TF radiator'
@weltersys
Art, any comments of the TF radiator for use in sealed and PR designs? I am borrowing from what I use to cool marine BLDC motors by dual purposing alloy foils. I think I have enough contact and surface engineered in so that the ambient drain is greater than the thermal load from the driver, if this statement makes sense, not sure how to word it. In an air-con room, it can be considered active cooling!

I made the Volcano Kiss concept very flat. The reason is that will use this concept to build that dual opposed mastering subwoofer for the workstation. The TF radiator in the air-con home studio is in hopes to use DSP to flatten to 16Hz. Hoping that the TFR will keep the voice coil/motor performance stable

Looking for your opinion on suitability of such a device as a studio mastering sub if the driver tests well for a smooth response with the 116dB to 120dB that I am expecting with 4Kw
 
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