@gp_freak I have a disassemble iwai 12inch subwoofer that's where I got 35mm winding height , I thought xmax of 12-13.5mm is at 82-85% BL strength and at 70% BL strength I thought it was around 15mm , I have to confirm with them ...
Let me know how it turns out. It would definitely be a notable one if it has 15 mm X Max. In the leagues of Sundown LCS 12
I get it , my idea was to use the filter in the low level signal path so that it starts to steeply roll off the signals below 17 Hz and save the subwoofer from exceeding x max. This signal can then be amplified. With this low tuning, without the filter, the sub will just self destruct. If i tune the sub high, then i dont need to use the filter.gp_freak - here's what I'm trying to say.
You mentioned looking at "high pass butterworth 4th order fiter". With a driver efficiency of 86dB and a 4th order crossover (two coils and two caps), you will have more losses.
Its all eating up into power and efficiency. Perhaps, rethink the idea of a passive crossover.
I have very little idea on the electronics side. So please explain ! I am assuming it has got something to do with the size of the caps. Also , please share your thought on what needs to be done to tackle the situation ! As you know, my need is to filter out the low frequencies !A 4th order HP (~8R) at 17hz needs 47 and 211 mH. Seriously ?
The requirement was to design it in that way. A higher inductance was requested by the client for his specific project.
Is it possible to build such subwoofers now with higher xmax and a lot lower Inductance ?The requirement was to design it in that way. A higher inductance was requested by the client for his specific project.
He opted for this ... Needed a sub driver in a front firing sealed box without using any passive of active crossover filters.
Shorting ring, copper cap or sleeve and many more innovative approach is quite common with my motor designs.
This particular model was made using multilayeted copper wire voice coil.
Usage of flat wound aluminium ribbon wire can be used to lower the inductance and increase the sensitivity and SPL along with the implementation of shorting rings in the same design.
That looks Good . Just tried to model it out now. Looks like one power hungry sub which can be built in a smallish vented enclosure. 30 litre box tuned to 30 to 40 Hz looks good, the issue is , cannot fit the port inside that small box. How ever this is one Driver to keep eyes on . Are these Drivers hand made and measured or there is a possibility to buy them off the shelf. Would be great if you can share the price here. The focus of this thread was to talk about the subwoofer drivers which are easily available in the market today in India along with their pricing to create a reference.Sone pics of a 12" sub driver I had made couple of years back. The t/s parameters are also attached along for reference.