Dual Sonosub Extravaganza. Need Help!

[intelonetwo]

Hello everyone, I'm on a mission to build my first Dual Sonosub. Actually I have two JBL GT1000D 10" DVC Car Audio Subwoofers that I would like to put to use in the dual sonosubs. The drivers are pretty robust with nice size magnets, motor structure, and weight. Below you'll find the drivers information.

JBL GT1000D
10” Component Low - Frequency Transducer
2” Dual - voice coil
I-beam basket
Specially treated pulp woofer cone
Sensitivity: 94dB (2.83/1volt)
Freq Response: 30Hz – 3.5kHz
2 or 8 Ohms depending on system wiring
Hi-roll rubber surround
Recommended power amplifier range:18W-275W
Mounting depth: 5-1/8”

I dont know the Thiel/Small Parameters. Anyone know where I can find this info for this driver?

I would like to get some input as to the proper design of the sonotube length, and diameter, port tuning, and size, as well as input about proper system integration.

First for the sonotube length and diameter. I like the size of the SVS 16-46PCi Subwoofers for their extension, and size. They are 16" in diameter, 46" tall, and are tuned to 16hz. I would like my sonosub to mimick this performance as much possible for a 10" DVC.

My goal for this project is for my sonosubs to take over where my mains lose steam. My main speakers are Definitive Technology BP2006TL's and a C/L/R 2300 Center Channel. The BP2006TL's are -3 down at 33hz, and -6 at 31hz. I would like my subwoofers to come in and take over below 33 hz and extend down as low as possible.

Next is port size, and tuning, I need to know how I can find the diameter of the port and length.

In the materials area, I plan to use the most economical materials I can. I plan to either have a friends father use his companies C-N-C machine mill the end caps out of 1" MDF. I plan to use 1 ply of 1" MDF for the end caps, meaning no gluing two pieces of 3/4" MDF together. I would like the woofer mounted on the bottom to avoid tipping, as I have a cat, and daughter. I will be finishing the end caps in gloss black paint, and the rest of the tube in speaker fabric. So as to match my mains which are finished in the same way.

What is the best, most economical, and easiest way to secure the end caps to the sonotube?

1. Threaded Rod
2. Screws into the side of the Sonotube into the MDF.
3. Silicone

This is my first sonosub project, however it is my 4th speakers project. And probably the easiest as far as design, complexity of the entire project goes of the 4 that I have done previously. For this project, the only real restrictions I have are economics, sonotube diameter (not more than 16"), due to placement issues in my room.

I plan to use a Nady XA-1100 1100 Watt Power Amplifier to drive both subwoofers. Since the JBL's are DVC I would like to use both voice coils and drivet he amplifier with more power, at a lower impedence.

Any help with this project would be appreciated. Along time ago, when I planning this project, I ran across a little software program that you could enter the frequency you wanted the system to extend down to, the driver size, etc, and it would spit out the sonotube size, lenght, port diameter, and length, etc. Anyone know of this program. It isnt one of the large speaker building programs like Speaker Easy, etc., it is specifically designed for sonosub's. It was quite useful.

[GrahamT]

Hi Thomas,

I dont know the Thiel/Small Parameters. Anyone know where I can find this info for this driver?

Yep, google. http://manuals.harman.com/JBL/CAR/Bo...rs/GT1000d.pdf

I plan to use a Nady XA-1100 1100 Watt Power Amplifier to drive both subwoofers. Since the JBL's are DVC I would like to use both voice coils and drivet he amplifier with more power, at a lower impedence.

That amp is overkill for those drivers.

Since you are putting a lot of effort into this project, I suggest you look at selling those drivers and upgrading to some higher excursion home theater 12s or 15s.

For example, compared to the SVS PCi subs, your drivers have around 35% less surface area and probably less than half the excursion. You wont be able to tune those drivers to 16 Hz. You cant really expect reasonble output that low from low excursion 10" drivers with a high Fs.

Just trying to help and save you time and money.

[GrahamT]

Is this the site you were looking for?

http://www.quux.net/roo/diy/sonosub/sonocalc.html

[intelonetwo]

GrahamT,
Thanks for the email on the Turkey day. I hear what your saying about the drivers, and I too knew they would be a less than ideal for providing low end for my home theater.

Let me ask you a question, what type of performance can i expect from these drivers? Can they reach any reasonablely low frequency with high enough decibals? Remember my Def Tech's are 8" drivers mated to a 250 watt amp each, and I have three across the front of my theater. Well the center channel actually has a 150 watt amplifier, mated to the 8" subwoofer. Nonetheless, I would like to know if you think the dual 10"ers from JBL will be able to go lower than the -3 down at 33hz of the Def Tech 2006TL's?

If not then it doesn't make since to waste time, and effort. The website that you supplied is great, and I will use it. It is not the program that I was referring to, but does a bit more.

Should the JBL's work in this situation for something, what amplifier would you suggest that is economical, and able to drive them to their limits?

[intelonetwo]

I looked at the sealed enclosure response and it looks like its a bit smoother throughout the range. Can a sonotube be built sealed in the same fashion as a ported design?

[GrahamT]

Hey Thomas,

Happy T-day.

The JBLs could probably dig deeper than the DTs but it is not worth the effort IMO. If you went sealed they would definitely not be worth the effort.

To get an idea of what you can expect you can download WinISD or UniBox modeller.

That Nady amp is just begging for some high excursion drivers like the Dayton RS drivers or TC sounds or Sound Splinters.

[SteveCallas]

I agree. Sell those drivers for as much as you can get away with and then buy one good 12" or 15" driver that is better suited to playing low.

[KeithM]

I looked at the sealed enclosure response and it looks like its a bit smoother throughout the range. Can a sonotube be built sealed in the same fashion as a ported design?

Yes they can, but I say you should just sell the drivers and get 1 or 2 good drivers.

[intelonetwo]

i suppose the consensus is that I should sell these drivers and buy a good HT Subwoofer. Ok.

What is a solid woofer that will privide the necessary low end that would take me down low enough so as to fill in below low 33 hz.

[GrahamT]

Here are some drivers to consider

http://www.partsexpress.com/webpage.cfm?&Webpage_ID=3&DID=7&CAT_ID=49&ObjectGroup_ID=484&SO=2

http://soundsplinter.com/rlp_premium_series_12_and_15_inch_subwoofer.html

http://acoustic-visions.com/

[intelonetwo]

Thanks for the links. I went and took a look at the subwoofers on those pages. I have seen a few, and not seen others. I like the SoundSplinter RL-p15d4, and the Dayton TIT400C-4-15" Titanic Subwoofer.

The most interesting subwoofer is the Tumult 15" with its Patented XBL2 motor. The price however is very high. No doubt the performance is probablyt something that needs to be heard or felt to be believed.

Are their any other subwoofers that will including such a motor stucture of the Tumult, in the size of a 15" or 12", but have reasonably affordable pricing?

It appears that the Shiva's are a bit long in the tooth with regard to Xmax, and cannot keep up with any of the subwoofers I have listed above.

Between the SoundSplinter RL-p15d4 vs. the Dayton Titanic 15". Which would you choose. Remember it needs to be strong below 33hz, above that I dont care, but below that I'd like it to be a true bottom feeder.

[GrahamT]

Well keep in mind that Adire drivers are not availble yet. There are going to be more drivers from Acoustic Visions with XBL2 that are fairly cheap, cheaper than the Shiva. They are going to be called the CX series IIRC.

I cant really pick between the Titanic and the SS because I haven't heard them. But if I were in your position, I would get the RL-p15. The Titanic and SS will both be strong below 33 Hz, no problem there.

Also, you probably want to cross over higher than 33 Hz. Relieving the DTs from that load will reduce IM distortion. I would cross somewhere between 60-80 Hz myself. You can do that with a pro amp and a crossover like the Paradigm X series, or the Outlaw ICBM if your receiver/pre-pro doesn't allow for it.