My First Sonosub/WinISD effort... - Home Theater Forum and Systems - HomeTheaterShack.com

Old 12-01-07, 02:45 PM Thread Starter
Shackster
jason

Join Date: Nov 2007
Posts: 7
My First Sonosub/WinISD effort...

Hello everyone,
This is my first time posting here, so please bear with me . Anyway, for the past few weeks I've been reading up on Sonosubs. I really like what I've seen so I decided to attempt one of my own. I'd like to use a 15" TC-9 hybrid 2 ohm DVC subwoofer I have thats just taking up space in my basement. I downloaded WinISD, loaded all the sub t/s parameters and I think I understand what I need to do. However, being that this is my first HT build and my first time using WinISD, I was hoping someone could double check me.

Here is the subwoofer information:
Revc = 4.0229 ohms
Fms = 27.3089 Hz
Zmax = 38.5442 ohms
Qes = 0.3948
Qms = 3.3876
Qts = 0.3536
Le = 4.0277 mH (at 1 kHz)
Diam = 325.7550 mm ( 12.8250 in )
Sd =83343.5655 mm^2(129.1828 in^2)
Vas = 152.9121 L ( 5.4000 ft^3)
BL = 19.5766 N/A
Mms = 219.1788 g
Cms = 154.9648 uM/N
Kms = 6453.0791 N/M
Rms = 11.1017 R mechanical
Efficiency = 0.7412 %
Sensitivity= 90.7176 dB @1W/1m
Sensitivity= 93.7030 dB @2.83Vrms/1m
Xmax = 22 mm

Ideally, I'd like to use a 24" diameter by 36" long sonotube, (I can go much higher than 3 feet else the wife will probably void the entire project), double 3/4 inch MDF endcaps (3/4 inside the tube, 3/4 inch outside) which would result in a net volume of about 255 L (before port/driver displacement).
From what I've read, 18 Hz seems like a good tuning frequency. So, I punched all this data into WinISD and it calculated a port size of 4" diameter by 8.63" length.
I looked over the various graphs that WinISD calculates and although they looked ok to me (based on other people's WinISD graphs I've seen online), I'm not experienced enough to know if what I'm looking at are the results I want.

Does all of this sound reasonable? Due to a lack of experience, I'm not sure about a lot of it, especially the port length, enclosure volume, and tuning frequency. Anyway, if anyone more experienced could critique my first effort to build a sonosub with WinISD, I would be forever grateful.

Jason

Last edited by howdogg; 12-01-07 at 02:56 PM. Reason: forgot some stuff...
howdogg is offline

Old 12-01-07, 06:41 PM
Elite Shackster

Mike

Join Date: Apr 2007
Posts: 19,397
Re: My First Sonosub/WinISD effort...

You are on the right track. You need to know the maximum power handling of the sub to figure out where maximum excursion occurs in this setup. From there we can figure out the port air speed and what diameter port will keep the air speed to an acceptable limit.
Mike P. is offline
Old 12-01-07, 07:43 PM Thread Starter
Shackster
jason

Join Date: Nov 2007
Posts: 7
Re: My First Sonosub/WinISD effort...

Thanks! I'm excited that I wasn't totally off base with this.
The person I purchased this sub from said it's 1000 watts RMS, but he had tested it with up to 2000 watt burps.
Anyway, I entered 1000 watts into the WinISD project under the "signal" tab. Then I checked the graphs for cone excursion and read port air velocity, but again I'm not sure how to interpret them.

Here are the graphs:

I'm not sure about the excursion, that might be ok as is, but I know the port air speed is way too fast. Whats my next step?

Thanks again!
Jason
howdogg is offline
Old 12-01-07, 07:53 PM
Elite Shackster

Mike

Join Date: Apr 2007
Posts: 19,397
Re: My First Sonosub/WinISD effort...

Excursion looks good with 1000 watt input. Airspeed is extremely high at this much power. Try to keep airspeed under 20 m/s by using larger ports or multiple ports. Maximum port length should be under 36 inches. What amp will you be using?
Mike P. is offline
Old 12-01-07, 08:18 PM Thread Starter
Shackster
jason

Join Date: Nov 2007
Posts: 7
Re: My First Sonosub/WinISD effort...

Thanks again for the response!
I was planning on using the Dayton HPSA1000 1000 watt plate amp, unless, of course, there is something better out there for the money .

Question, at what frequency should the air speed be under 20 m/s? I assumed 18 hz (which is the frequency the box is tuned to).

Using one 6" by 22" port, the air speed is 45 m/s at 18 hz. Using two 4" by 21" ports, it's even higher. Two 6" ports would require a length of 48" so thats out. Whats my next step now, how do I get that airpseed down? Do i need to increase the volume of the enclosure or what? All suggestions greatly appreciated!

Jason
howdogg is offline
Old 12-01-07, 08:20 PM
Elite Shackster

Mike

Join Date: Apr 2007
Posts: 19,397
Re: My First Sonosub/WinISD effort...

I'm curious where you got the specs from. The TC-9 specs I found are alot different from what you posted.

http://web.archive.org/web/200408302...15tc9_2570.pdf
Mike P. is offline
Old 12-01-07, 08:39 PM Thread Starter
Shackster
jason

Join Date: Nov 2007
Posts: 7
Re: My First Sonosub/WinISD effort...

The specs came from the person I purchased the sub from. It's kind of a grey area since the subs are not true TC-9's. Here's a link to some info about them.

Anyway, the person i bought it from (and took the measurements) owns a car audio company named Sundown Audio, so he is experienced and knowledgable in this area. He said in a post in that link that these arent true TC-9 subs, they are TC-9 "based" subs so I suppose that is why the parameters are different although I'm no expert by any means.

Do you think I should use the parameters you found? or is there anything else I can do with the parameters I have to get the port airspeed down to where it needs to be?

Thanks again!
Jason
howdogg is offline
Old 12-02-07, 02:18 PM
Elite Shackster

Mike

Join Date: Apr 2007
Posts: 19,397
Re: My First Sonosub/WinISD effort...

Use the parameters you posted since the subs are TC-9 OEMs and they were measured by Sundown Audio. As for the air speed issues, all I can suggest is a bigger cabinet as in a LLT design or the use of passive radiators.
Mike P. is offline
Old 12-03-07, 11:54 AM
Elite Shackster

Josh

Join Date: May 2007
Location: Louisville, KY
Posts: 2,431
Re: My First Sonosub/WinISD effort...

Howdogg,
Try using a slot port or 3 4" ports. You can increase your port area to reduce your airspeed. Just keep your length at 36" or less due to resonance issues.
Ricci is offline
Old 12-03-07, 01:13 PM
Elite Shackster

Mike

Join Date: Apr 2007
Posts: 19,397
Re: My First Sonosub/WinISD effort...

I've been modelling this sub in WinISD and the best I can come up with is 350 liters tuned to 16.5 hz with one 8 inch port 32 inches long. Max power would be 500 watts to keep the air speed within limits. Hopefully someone else will chime in here if they have any ideas on this sub.
Mike P. is offline

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