Torrent Audio Mistral 12 DVC

**jwh7399** · **05-08-08, 09:23 PM**

I had initially planned on building a sonosub. I had modelled it using sonosub.exe. I came up with around 3.6 cu.ft. tuned to 20hz with two 3" ports 25" long. I guess I'de like to build the best sub I can with what I have. I have a Mistral 12 and a 4ohm db-500 svc but don't know enough to make an intelligent decision on which driver to use and for what. I'm almost ashamed to admit that I also bought 2 of the TC sounds 12" closeout drivers from PE and I don't even know what to do with the first two that I already had! Oh well, hopefully the Mistral and the db-500 will help me learn enough to do something nice with the twin "closeouts". I haven't even built a sub yet and I'm an addict!

**jwh7399** · **05-08-08, 09:29 PM**

That looks OUTSTANDING!!! Very nice work! The driver is going to look awesome next to that finish. It's almost a shame to put a grill over that, but we all know how little fingers like to poke and pull on stuff.

Excellent job!

**eyekode** · **05-08-08, 09:41 PM**

Quote:

jwh7399 wrote:

I had initially planned on building a sonosub. I had modelled it using sonosub.exe. I came up with around 3.6 cu.ft. tuned to 20hz with two 3" ports 25" long. I guess I'de like to build the best sub I can with what I have. I have a Mistral 12 and a 4ohm db-500 svc but don't know enough to make an intelligent decision on which driver to use and for what. I'm almost ashamed to admit that I also bought 2 of the TC sounds 12" closeout drivers from PE and I don't even know what to do with the first two that I already had! Oh well, hopefully the Mistral and the db-500 will help me learn enough to do something nice with the twin "closeouts". I haven't even built a sub yet and I'm an addict!

Two 3" ports really isn't that much more port area. It would still hit 18m/s with pretty low power.

So... you have 4 drivers and no box? Hehe

.

Oh, I have your plan: 4 sonosubs. One in each corner of the room

.

jk, I would not do this. I had two subs for a while. I think that unless you are very flexible in placement of the subs it is difficult to avoid making big nulls in your room.

You are not going to like this, but for similar cost I would go with a Maelstorm sealed in 4cu. Add a little eq and it could probably beat all four of your current drivers. You might even be able to ebay the 4 subs and get enough for the Maelstrom.

But it really comes down to your goals. How loud do you want? How low do you need to go? Is this for Music? Hometheater? Both? Are you putting them in more then one room? What size cabinet can you live with?

**eyekode** · **05-08-08, 09:51 PM**

Ok, so I actually ran the numbers and a single Maelstrom will not beat your 4 drivers

. Especially not sealed. Ported it is 3db down from your 4 drivers but only requires half the box volume (8cu vrs 16cu).

Sealed it would take a lot of EQ and ~4x the power but only a ~4cu box.

Oh man, I have a problem too

. My meager 100db @ 20hz is really sufficient, but it is fun to dream.

**jwh7399** · **05-08-08, 10:09 PM**

I'de like to build one just for music and 3 for HT. 2 of the 3 will be in the same room(twins). None of them need to be really loud(small children). I think the HT would be fine down to 20hz and the music sub maybe 30hz. I can live with any size cabinet that I need to. I think when the kids get a bit older I'll do a 15" or 18" monster.

**jwh7399** · **05-08-08, 10:10 PM**

It IS fun to dream for sure!

**eyekode** · **05-08-08, 10:27 PM**

Quote:

jwh7399 wrote:

I'de like to build one just for music and 3 for HT. 2 of the 3 will be in the same room(twins). None of them need to be really loud(small children). I think the HT would be fine down to 20hz and the music sub maybe 30hz. I can live with any size cabinet that I need to. I think when the kids get a bit older I'll do a 15" or 18" monster.

My personal opinion of the Mistral is that it works pretty well ported for HT. Only caveat is the DVC 4ohm coils are hard to get the most out of with a plate amp. So if you have an old amp lying around and you don't mind the bother of having to turn it on when you want to use it then you could have a really inexpensive sub.

For music you could seal the db-500 in a 4cu box or a smaller stuffed box to reach a Q of ~.5. This driver should work great with a plate amp.

Then as you said you could use the twins for your HT room. This is assuming the drivers can actually play low. I am not sure this is true. I remember modeling them when I saw the price, but I don't remember being too excited... What are the T/S parameters?

**jwh7399** · **05-08-08, 10:34 PM**

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** · **05-08-08, 10:38 PM**

How much amp would I need for the db-500 sealed? Maybe I should ebay the Mistral and put that towards a plate amp.

**eyekode** · **05-08-08, 10:41 PM**

Quote:

jwh7399 wrote:

How much amp would I need for the db-500 sealed? Maybe I should ebay the Mistral and put that towards a plate amp.

When I modeled it in WinISD it looks like ~250w would get the most out of the driver's Xmax.

**jwh7399** · **05-08-08, 10:43 PM**

So a PE plate would work. Hmmmm

**eyekode** · **05-08-08, 10:57 PM**

Quote:

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.

That is really cool that they came with actual driver measurements!

This models very similar to the db-500 for a sealed alignment. For a ported alignment the db-500 looks to be ~2db higher at the cut off frequency (~20hz) using the same box volume and port. But the clearance sub still looks pretty good. And I am not sure I trust the Mistral's T/S parameters to be as good as they claim. My initial measurements in room have the f3 at ~24Hz not the predicted 19hz. This could just be an anomaly of my room. I still have to measure the sub outside to be sure.

**eyekode** · **05-08-08, 11:04 PM**

Quote:

jwh7399 wrote:

So a PE plate would work. Hmmmm

I really like the BASH amps and the O-Audio amps because they are much more efficient then a typical class A/B amp. But I am partial to low-power because I only have 1 15amp circuit running to my entertainment center. The same circuit is shared by 3 PC's!

**jwh7399** · **05-08-08, 11:12 PM**

I like the Oaudio amps, It just seems that the Dayton amps have more bang per buck. I should think about what I'll be running on the same circuit before I get nuts and start ordering things.

**jwh7399** · **05-08-08, 11:14 PM**

I have a Crown amp that will do 850w @ 4 ohm per channel that I can use for the twins. I also have a BFD that I can use on those.

**eyekode** · **05-08-08, 11:30 PM**

Quote:

jwh7399 wrote:

I have a Crown amp that will do 850w @ 4 ohm per channel that I can use for the twins. I also have a BFD that I can use on those.

Ouch! You have amp to spare. In fact you have enough amp to destroy those drivers. Looks like ~200w would bottom one of these out in a ported design @ ~20hz.

**Warmon** · **05-09-08, 11:20 AM**

Quote:

jwh7399 wrote:

I like the Oaudio amps, It just seems that the Dayton amps have more bang per buck.

What make the Oaudio a good buy IMO is the built-in parametric equalizer. You'd have to pay another 100 bucks or so to get this functionality by adding another device.

**jwh7399** · **05-09-08, 11:22 PM**

Quote:

Warmon wrote:

What make the Oaudio a good buy IMO is the built-in parametric equalizer. You'd have to pay another 100 bucks or so to get this functionality by adding another device.

I wish the 300w Oaudio had the PEQ feature. I hate to buy a 500w amp if I don't need that much, but it is cheaper than the alternative.

**jwh7399** · **05-09-08, 11:27 PM**

Quote:

eyekode wrote:

Ouch! You have amp to spare. In fact you have enough amp to destroy those drivers. Looks like ~200w would bottom one of these out in a ported design @ ~20hz.

How do the commercial guys like SVS put similar drivers in a ported enclosure tuned to 16hz and use a 525w amp? Is there something built into the amp? The more I learn, the less I know.

**eyekode** · **05-10-08, 06:54 AM**

Quote:

jwh7399 wrote:

How do the commercial guys like SVS put similar drivers in a ported enclosure tuned to 16hz and use a 525w amp? Is there something built into the amp? The more I learn, the less I know.

I think they have a couple things working for them:
* The amp really cannot deliver 525w RMS
* Unless the port system is really overbuilt compression detunes the box making the port less efficient. I.e. the model is not complete enough to truly predict the behavior with large signals.
* They put high pass filters in the signal chain to protect the drivre.

**Blaser** · **05-10-08, 09:19 AM**

I would say we do not know the driver parameters as well. And from the other side, a sub can take a lot of power when it comes to program materials (probably more than what modelling suggest, I prefer to work on RMS values).

**jwh7399** · **05-10-08, 08:14 PM**

So, the db-500 and an Oaudio 500w amp with PEQ in a sealed configuration would be a suitable combination for a music only sub? What is the typical tuning frequency of a music only sub? Is there an optimal box size/frequency specifically for this driver?

**jwh7399** · **05-10-08, 08:18 PM**

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

**jwh7399** · **05-10-08, 09:26 PM**

Does the 500w Oaudio have a built in high-pass filter?

**eyekode** · **05-11-08, 10:13 AM**

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.

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