Torrent Audio Mistral 12 DVC

[Blaser]

jwh7399 wrote:

These are the T/S parameters from TC:

12" dB-500 SVC

Qts 0.447
Qes 0.481
Qms 6.347
Fs 24Hz
Res 3.25Ω
Ls 2.36
Lp 3.51
Rp 2.91Ω
Dia 241mm
Vas 71.5l
mms 169g
cms 244um/M
bl 13.3Tm
Spl 86dB

What about the other drivers?

[jwh7399]

These are the specs for the 2 TC Sounds 12" closeout drivers

jwh7399 wrote:

These are the t/s from PE
Specifications:
*Power handling: 600 watts continuous
*VCdia: 2"
*Le: 2.49 mH
*Impedance: 2 ohms per coil
*Re: 4.2 ohms (coils wired in series)
*Frequency range: 21-500 Hz
*Fs: 21 Hz
*SPL: 89.3 dB 2.83 V/1m
*Vas: 4.66 cu. ft.
*Qms: 4.25
*Qes: 0.41 *Qts: 0.38
*Xmax: 22 mm

The subs came with sheets that list the actual measured parameters for each driver, but we are in the process of moving and the subs are at the new house.

[jwh7399]

eyekode wrote:

The bass boost includes sub-sonic filtering. And the PEQ could be used to further tailor response: http://www.oaudio.com/docs/manual.pdf

Many suggest a Q of .505 for best transient response. Put these parameters in WinISD pro and adjust the box volume to find the Q you want. Note that you can also stuff a sealed sub to lower Q. This can be modeled in WinISD by adjusting Qa. I have heard a fully stuffed box has Qa ~10.

When I try to run WinISD pro on my laptop it causes it to freeze. I'll have to try it on my other computer and see if that works better.

I'm thinking that I'll try for fully stuffed to get the smallest box that I can.

Is there a more cost effective way to get around 300w @ 4ohm with PEQ? Although, the Oaudio 500w seems like a great deal for $242 shipped.

[eyekode]

jwh7399 wrote:

When I try to run WinISD pro on my laptop it causes it to freeze. I'll have to try it on my other computer and see if that works better.

I'm thinking that I'll try for fully stuffed to get the smallest box that I can.

Is there a more cost effective way to get around 300w @ 4ohm with PEQ? Although, the Oaudio 500w seems like a great deal for $242 shipped.

Hrm... there are always more cost effective ways to go. Depends on the effort you want to put forth. But I don't know of any amp cheaper then the 500w oaudio that has a built-in PEQ.

If you don't mind turning extra stuff on then you could use BFD for the EQ. This is for your music sub right? In this case you really don't need sub-sonic filters (which the BFD cannot provide). But this would get you back really close to the 500w oaudio in cost.

I like to take an incremental approach. For the sub I just built I used an external amp. I already had one sitting around. And if it turns out I really want a plate amp I can still add that later by cutting a larger hole.

[eyekode]

I finished the poly coats and put the sub back together. One build note:

Make sure to get some paint/stain on the edges of driver recesses. Otherwise when the driver is mounted you might see some of the bare wood shining through. I had to go back with a magic marker . Don't over do the paint though, especially if you have tight tolerances.

Here are the final pictures: http://photos.ganzhorn.org/2008_random
I also posted a bunch of galleries showing the intermediate stages of the finish.

I ran REQ last night. Initial curves are not quite what I expected. Seems to start rolling off in room at 30hz with a ~8db/octave slope. Cannot explain it, should start rolling off ~20hz. I also have a big null at my listening location ~46hz. I need to try to fix the room though instead of boosting EQ. Because over by the side of the entertainment center it is boom'n at 46hz. Wouldn't want to increase this.

[jwh7399]

eyekode wrote:

Hrm... there are always more cost effective ways to go. Depends on the effort you want to put forth. But I don't know of any amp cheaper then the 500w oaudio that has a built-in PEQ.

If you don't mind turning extra stuff on then you could use BFD for the EQ. This is for your music sub right? In this case you really don't need sub-sonic filters (which the BFD cannot provide). But this would get you back really close to the 500w oaudio in cost.

I like to take an incremental approach. For the sub I just built I used an external amp. I already had one sitting around. And if it turns out I really want a plate amp I can still add that later by cutting a larger hole.

This is for a music sub. I actually have a BFD that I got some time ago for my pathetic HT sub and never hooked it up. We're planning on moving and it seemed a waste.

If you add a plate amp later on, won't it change the volume of the enclosure? I do like the idea of doing things in increments. I should really have thought about that before I bought 4 drivers.

[jwh7399]

That looks Amazing!!!!!!! WOW!!

The whole system looks sweet! That sub looks like it was purchased at a high end store.

[eyekode]

jwh7399 wrote:

This is for a music sub. I actually have a BFD that I got some time ago for my pathetic HT sub and never hooked it up. We're planning on moving and it seemed a waste.

If you add a plate amp later on, won't it change the volume of the enclosure? I do like the idea of doing things in increments. I should really have thought about that before I bought 4 drivers.

Yes it will change the volume. But the change in volume will be pretty small and your room will have way more affect on the sound then this small change in volume. Only real negative of this approach is you will probably mess up the finish putting in a new hole.

[eyekode]

jwh7399 wrote:

That looks Amazing!!!!!!! WOW!!

The whole system looks sweet! That sub looks like it was purchased at a high end store.

Thanks! I think the size is perfect and the finish is pretty good. But if you get close you can tell it is homemade . Especially the finish on the beveled edges. I should have spent some more time with some wood filler on them. But at one point I thought I was just going to poly it and didn't want the wood filer to dork-up the real wood look.

I am not really happy with the "T" or the aluminum cone. But the grill should mostly hide it.

Also vibration is an issue at some frequencies. The entertainment center doesn't shake much, but the center channel seems to vibrate more. One of my co-workers recommended putting a bike tube under the sub/center and inflating it slightly. This sounds like it is worth a shot.

[jwh7399]

eyekode wrote:

Thanks! I think the size is perfect and the finish is pretty good. But if you get close you can tell it is homemade . Especially the finish on the beveled edges. I should have spent some more time with some wood filler on them. But at one point I thought I was just going to poly it and didn't want the wood filer to dork-up the real wood look.

I am not really happy with the "T" or the aluminum cone. But the grill should mostly hide it.

Also vibration is an issue at some frequencies. The entertainment center doesn't shake much, but the center channel seems to vibrate more. One of my co-workers recommended putting a bike tube under the sub/center and inflating it slightly. This sounds like it is worth a shot.

I like the look of the aluminum cone, I feel ya on the "T". I've actually used carpet pad to isolate things from vibration. I found some really cheap stuff that is 1/2" closed cell foam that almost feels like one of those stress balls that you squeeze in your hand. I can't remember where I got it, but if you can't find anything that works, let me know the size you need and I'll send you some(no cost). I set a 50lb subwoofer on a peace of it and the sub became silent.

[eyekode]

I still have a couple things I could try. But that is really neat sounding stuff. If you figure out what it is called let me know!

[jwh7399]

eyekode wrote:

I still have a couple things I could try. But that is really neat sounding stuff. If you figure out what it is called let me know!

I can't find a name on it. I'm quite sure it was in the flooring department at Menards or Lowes. I'm also quite sure that it is padding for floor coverings. I'll be in both of the stores over the next week or so, I'll look and see if I can find more info.

[Mike P.]

Nice work on the sub! It looks well integrated into your setup. Now about that 30 hz roll off. What amp are you using to power the sub?

[eyekode]

Mike P. wrote:

Nice work on the sub! It looks well integrated into your setup. Now about that 30 hz roll off. What amp are you using to power the sub?

I am using a crown PS-400. It doesn't start any roll-off until 10hz (by spec, I have not measured yet). I need to measure my whole signal chain. Even with the 8db slope from 30hz bass is much improved in my room.