Finding the right cabinet design for the right driver (1 Viewer)

[DonnyC123]

I'm looking for a little insight for which cabinet is right for my driver. I'm curently using a Ciare 15.00 Sw driver in a Mackie Sw1501 cabinet. http://www.usspeaker.com/ciare%201500sw-1.htm link for Ciare 15 Sw http://www.mackie.com/products/swa1501/ link for Mackie Sw1501 Again, I'm only using the cabinet from the Mackie which I picked up second hand. My only use for this sub is for home theater and the more I'm reading the less convinced I am that this is the way to go. I'm relatively new to this so I could be wrong. The Mackie cabinet states that this is a double horn loaded design. It's quite odd. The front of the cabinet has a small chamber with vent for the front of the driver and the back is a separate chamber that feeds into two horns. Which is basically almost the length of the entire cabinet with a piece of wood dividing it into the two parts at the bottom of the cabinet. There are no flares on the horns. For home theater I'm not sure if this setup is getting me down to 20 hz or not. Will this type of enclosure limit frequency response down to 20 hz even if the driver is rated for it? I'm pushing 1475w rms from an Audiotrak amp into the Ciare 15 sw which needs a ton of power. It sounds mighty but I'm looking to get the most out of the system. Any insight would be great. Thanks to all for the time -Don

 

[Robert_J]

For home theater I'm not sure if this setup is getting me down to 20 hz or not.

Not even close. The enclosure is ported and based on the specs of 36hz it is probably tuned to around 40hz.

Will this type of enclosure limit frequency response down to 20 hz even if the driver is rated for it?

It doesn't matter what the driver is rated for. Sending information to a sub below the enclosure's tuning frequency is a recipe for disaster. Look at the Thiele/Small parameters on the driver. Xmax is 11.5mm. That's great for a sub designed to reproduce live rock music, not one that is designed for a home theater.

I'm pushing 1475w rms from an Audiotrak amp into the Ciare 15 sw which needs a ton of power.

That power, coupled with sending information lower than the enclosure's tuning frequency will destroy your driver via over excursion. And your sub doesn't NEED a ton of power. In fact with 92db/1 watt sensitivity, it shouldn't need much power at all to play LOUD. It just won't play low. The 4" voice coil will handle a lot of power as long it plays frequencies it was designed to play.

Any insight would be great. Thanks to all for the time

Start over. Neither the driver nor the enclosure is designed for a home theater. If you had a band, it would be great. For example, I use a pair 15" TC-3000's in my home theater. http://web.archive.org/web/20070402025330/http://www.tcsounds.com/tc3000.htm Look at the T/S parameters for the drivers. 1. The xmax is 30mm (yours 11.5) 2. The sensitivity is 88.6 (yours 92.5) 3. The Fs is 22 hz (yours 38.2 hz) The TC Sounds sub is designed to play LOW but requires a lot a power to get there. Your sub is designed to play LOUD but not require a lot of power. If you want to start over, we need a budget. And what amp are you currently using?

 

[DonnyC123]

Thanks, That was very helpful. Is the ciare 15" a good fit for the enclosure? I've played with bands on and off and if it's a good fit I'll just leave it for live sound reinforcement. The tc-3000's have a Quad voice coil.... I haven't run into this before. According to the wiring schematics it's possible to run it a .35 ohms. Is that correct? Is there any amp that can handle that low of impedance? Could you go into a little more detail? The amp I'm currently using is an Audiotrak at 2500 http://www.audiotrak.com/pdfs/AT-800-1400-2500-Amps.pdf Would that amp be suitable to push these drivers? Would one or two drivers be optimal based on the amp?

 

[Robert_J]

You didn't give me enough information about the enclosure. What's the net volume? The real tuning frequency? I guessed based on published specs. I can't be sure without those details. You can't even get a TC-3000 any more. Parts Express sells the Axis model now. It's close to the 3000 but with some minor tweaks. But there are dozens of other options as well. If you can live with a large cabinet, then there are some 18" subs that may fit your needs better. And yes, that is a quad voice coil. Thilo (the designer and owner of TC Sounds) likes to give the user options for wiring. They market to the car audio crowd and there are car amps that can push a .35 ohm load. They also require extensive upgrades to the car's electrical system like additional batteries and high output alternators. I've never heard of anyone using that amp brand but pro amps work great in home theaters. I use a Behringer EP-2500. I just answered a question from guy with a Behringer iNuke amp. It has tons of power so it can push any combination of drivers you choose. You need to choose your subs based on your budget and your goals. What's your room size? Do you want to hit reference levels while watching some of the newer action movies with bass down in the subsonic level? Black Hawk Down is the top one with a scene containing 5hz pulses. There are only a handful of guys that can really hit that low and loud. Dual 15's gets my 16x25 room rocking down to 15hz. While you are thinking of things like budget, take a look at the current crop of TC Sounds subs and Dayton subs at Parts Express. Sundown Audio and Stereo integrity have some good subs as well. PSI Car Audio can custom design a sub for you. If you can provide a motor (magnet structure) with a 4" coil, he can really go nuts. His current offerings are only in the 3" coil size but up to 18".

 

[DonnyC123]

I'm looking for the specs on the Mackie cabinet - I found this : –3 dB Response: 47 Hz–120 Hz –10 dB Response: 36 Hz–120 Hz , not sure if that gives any insight into the cabinets tuning. The volume comes out to 5.54 cubic feet. There is a small vented chamber in the front that accounts for some of this. What kind of design are you using for your dual 15" s? How much power for them, too? I was talking with my friends brother, who is very enthusiastic when it comes to audio, and he was talking about a transline cabinet he has and making a copy of it for my system. I just need to find a suitable driver. His cabinet was for a 15" but I wonder if an 18" would work better. If this design doesn't require a ton of power I can always run just a single channel off of my power amp instead of bridging the two channels. Any thoughts about this route? My theater room is 12'x22' and 10' high. Thanks again!

 

[Robert_J]

The 36hz gives me an idea of the cabinet's tuning frequency but that's it. I use a pair of cabinets that are approximately 3 cubic feet. This isn't my design but is perfect for a these type subs - http://www.danmarx.org/audioinnovation/tc3000.html Each of my drivers is wired for 2 ohms which allows my EP-2500 to push about 800w at 20 hz. I've never maxed out either the drivers nor the amp even when giving demos. I fear for the structure of my room and adjoining rooms before I reach the limits of the subs. My room is slightly larger than yours. T-line subs require specialized drivers and the margin of error in building is not very forgiving. A sealed box is very forgiving on the size. Plus, they don't require a subsonic filter.

 

[DonnyC123]

Gotcha, duely noted regaurding the T-Line designs. My amp states that there is a 10 decibal roll-off as it approaches the 5 hz mark. Would this qualify as a subsonic filter? I may experiment with the design but it is definataley a project for down the road sometime. Right now I'm looking for a sub that'll get me as low as i can past 20 hz for around $500 (give or take). I might even go with a woofer that has already been paired with a cabinet. I'm getting a better idea of what to look for in the specs to see what they really can acheive based on frequency ratings. Any suggestions for this criteria? I'm going to continue using my Audiotrak amp so the sub doesn't need to be powered. Are your tc-3000's sealed in the cabinets you're using?

 

[Robert_J]

Are your tc-3000's sealed in the cabinets you're using?

They work better in a sealed enclosure. Look at their BL number. That's motor strength. Or look at the size of the magnet structure. 45 pounds is quite large for a 3" coil. I also have a custom 3" coil sub that has a magnet structure that is close to 60 pounds.

I'm getting a better idea of what to look for in the specs to see what they really can acheive based on frequency ratings. Any suggestions for this criteria?

It's more about the enclosure than the sub.

Right now I'm looking for a sub that'll get me as low as i can past 20 hz for around $500 (give or take).

Can you do four 15" subs? Each cabinet being about 6 cubic feet net.

 

[DonnyC123]

I could do 4 15" subs. What would be the dimensions of a box with 6 cubic feet net? My current sub missed the mark when I assembled it. I appreciate the guidance so that I don't make the same mistakes. Do you have specific drivers in mind for these boxes?