Hi,
I never heard of such stories.
Would be interested in where to find such reports and under what circumstances the denting occured.
I certainly never had a dent in one of our TCSounds, but just rocksolid performance.
Besides the TC Epic12 or its costier brother LMS-R12 the Dayton Ultimax are probabely the best suited drivers for this application
jauu
Calvin
I never heard of such stories.
Would be interested in where to find such reports and under what circumstances the denting occured.
I certainly never had a dent in one of our TCSounds, but just rocksolid performance.
Besides the TC Epic12 or its costier brother LMS-R12 the Dayton Ultimax are probabely the best suited drivers for this application
jauu
Calvin
Hello Calvin
I did read that somewhere once and managed to find it again on the feedback section on the PartsExpress website.
TC Sounds Epic 12" DVC Subwoofer
The Rhythmik drivers come to mind. I believe they are still available separately but are probably expensive. The Dayton HF and HO series also but they have moderate xmax around 12-15mm except for the 18 which effectively has a bit more.
The TC's I have a lot of experience with. The cones can be dented but typically large deformations are due to mechanical bottoming which is after 2.5" peak to peak even on the lowly Epic. The cones will get small dent fairly easily too. Just do not drop anything hard on the cones. For example dropping a large screw onto the cone for example while mounting or unmounting the driver, will leave a tiny dent. You just have to be careful. The LMSR series can be really good.
The TC's I have a lot of experience with. The cones can be dented but typically large deformations are due to mechanical bottoming which is after 2.5" peak to peak even on the lowly Epic. The cones will get small dent fairly easily too. Just do not drop anything hard on the cones. For example dropping a large screw onto the cone for example while mounting or unmounting the driver, will leave a tiny dent. You just have to be careful. The LMSR series can be really good.
It's funny because the previous series of those drivers did have aluminium cones with an Xmax of 16mm. Now they are using a plastic bucket insert design which is no good for this sort of application.
cheers
I presume the aluminium must be very thin if they are susceptible to the slightest dint. In my application I usually test drivers quickly by blue-tacking on the accelerometer but this requires a reasonable force so I can see these cones being damaged easily.
Most of the Dayton aluminium cone drivers have Xmax's of around 14 mm with 2 stack magnets which means they were probably aimed at vented box designs rather than sealed box designs.
cheers
Great to see this thread revived. This has been a project I've wanted to hear more about for a year now.
How major of an issue are these modal resonances? I've really been wanting to see your DSP servo setup used on one of these monsters (which I had thought would've been nearly ideal match up) for the ultimate in bass. But if that's a severe issue and with a diaphragm that large...dang.
(Although, one wouldn't be using a driver like that above 100Hz anyways.)
For what you're looking for, it might not hurt to drop a message Paul's way at Pierce Audio Products. A custom driver to your specs might be the way to go and these folks seem to be a good option for that even if they never seem to get their name out there. I've seen one of their monsters done up with an aluminum cone, so I know they've done it in the past.
Doubt they could do titanium cones like Eclipse and AudioPulse (TC Sounds) used to do. Titanium makes everything that much more awesome (and with a higher resonance frequency).
How major of an issue are these modal resonances? I've really been wanting to see your DSP servo setup used on one of these monsters (which I had thought would've been nearly ideal match up) for the ultimate in bass. But if that's a severe issue and with a diaphragm that large...dang.
(Although, one wouldn't be using a driver like that above 100Hz anyways.)For what you're looking for, it might not hurt to drop a message Paul's way at Pierce Audio Products. A custom driver to your specs might be the way to go and these folks seem to be a good option for that even if they never seem to get their name out there. I've seen one of their monsters done up with an aluminum cone, so I know they've done it in the past.
Doubt they could do titanium cones like Eclipse and AudioPulse (TC Sounds) used to do. Titanium makes everything that much more awesome (and with a higher resonance frequency).
Hi,
hit the TCs with my fist, even kicked it ... no dents nothing, nada.
So either the Alu domes are robust enough, or I'm a wimply wimp
jauu
Calvin
It happens.
Or the drivers haven't nearly enough of a xmech buffer past xmax. I've bottomed my LMS-U (not hard, fortunately) way, way too easily. Hook up a servo setup that can easily push a cone too far and...
Not mine, thankfully, but too easy to do. It's a flaw with the TC Sounds drivers' design, frankly. Not the same as denting the cone attaching an accelerometer, but still a very real concern here.
Attachments
Yes I know about those. They have limited Xmax unfortunately and their power handling is a bit light on for my app.
Metal cones have better controlled frequency response characteristics compared to paper or plastic. However metal tends to ring at higher frequencies because it has lower damping but it is much easier to attentuate this ringing when it is a sharp resonant peak at higher frequencies compared with a lower Q, lower resonant frequency of paper or plastic cones. It is also less susceptible to flexing compared to paper or plastic.
cheers
Hi,
from those pics only the third looks as if the dent occured due to overload.
The first and especially the second look like some nerd tried to evaluate the amount of stroke by probing with a screwdriver
When I accidently dropped a knife into my stainless kitchen sink a similar dent occured.
So far the TCs I had took any 'normal abuse' without issues.
But then, there are nerds who certainly define abuse different.
If You look for vids on Youtube, where windshields of cars break while the drivers still work flawlessly, one may wonder though if the dented drivers weren't purposely destroyed by a childish or idiotic mind with a deep desire for destruction.
jauu
Calvin
from those pics only the third looks as if the dent occured due to overload.
The first and especially the second look like some nerd tried to evaluate the amount of stroke by probing with a screwdriver
When I accidently dropped a knife into my stainless kitchen sink a similar dent occured.
So far the TCs I had took any 'normal abuse' without issues.
But then, there are nerds who certainly define abuse different.
If You look for vids on Youtube, where windshields of cars break while the drivers still work flawlessly, one may wonder though if the dented drivers weren't purposely destroyed by a childish or idiotic mind with a deep desire for destruction.
jauu
Calvin
Wow and yet another superb project from you !!!!
I will also subscribe to this thread as i will be needing 16 15" servo subs to fill my home theater infinite baffle concrete wall holes in the near future
and always enjoy having quality options !!
old pic from the construction time .. ( ouff..time flies! )
I will also subscribe to this thread as i will be needing 16 15" servo subs to fill my home theater infinite baffle concrete wall holes in the near future
and always enjoy having quality options !!
old pic from the construction time .. ( ouff..time flies! )
Attachments
Had quite a few enquiries regarding this project. Unfortunately I have been allocating most of the time to the DSP Preamp/Crossover project so have little time for anything else. When I have finished this I will get back onto this project as there have been a number of improvements that I have been wanting to pursue.
regards
regards
Ding, ding, ding. Hello everybody. Did you notice in Post 1 that distortion at 20 Hz went from 28% to 1% with 30 dB of motional feedback?
A nice ACH-01-4 from eBay came in the mail yesterday. With shipping, came to us$18. And last month, a dual voice coil woofer arrived. And before that, I dug out my old bridge-motional-feedback amp. So, this is going to be motional feedback R&D season for me.
Question: can anybody say for sure if DSP is fast enough to put into the feedback loop?
Ben
Motional Feedback, the last frontier
A nice ACH-01-4 from eBay came in the mail yesterday. With shipping, came to us$18. And last month, a dual voice coil woofer arrived. And before that, I dug out my old bridge-motional-feedback amp. So, this is going to be motional feedback R&D season for me.
Question: can anybody say for sure if DSP is fast enough to put into the feedback loop?
Ben
Motional Feedback, the last frontier
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For me it wasn't. Latency/delay from analog->adc->dac->analog was too high.
For instance, Latency of 1 ms is 180 degrees of phase/delay at 500 Hz
I went analog/traditional and had nice results.
To see some progress of my project (in Dutch);
Hypex DS 1.2 MFB-mod - MFBfreaks.com
For instance, Latency of 1 ms is 180 degrees of phase/delay at 500 Hz
I went analog/traditional and had nice results.
To see some progress of my project (in Dutch);
Hypex DS 1.2 MFB-mod - MFBfreaks.com
My initial intuition as well. Which leads to my first-ever metaphysical question: can you insert a compensatory time-adjustment in a feedback loop?
Any metaphysicians out there?
And what happened to the OP and his mic?
Ben
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