I have decided I want to build my own sub

[BigSkreen]

I have been looking around at kits and other stuff and I saw that most people here did it with much simpler designs that the eD kit for instance. I have been reviewing posts and looking online. Since I'm most likely putting STs up front I'll have a good response down to about 40Hz or so. I'd like my sub to raise the SPL a little on the low end and go down low. So here was what I was thinking:

1. Ported design

2. I'd like to use the Audioplulse Axis 15" but this is the best I could find (little disappointed that it doesn't have the gorgeous blue finish) http://www.parts-express.com/pe/showdetl.cfm?Partnumber=293-618

Note: They have a Quad Voice coil but that just seems ridiculous all though it is the same price

3. I plan on using the EP2500 or EP3000 to power it (I'll have a lot more questions about this later)

When I used WinISD to model this sub I'm about 700% sure I did it wrong. I modeled it in a box that is 6.7 ft^3. But here is what I got:



That would be a box roughly 1.5'x1.5'x3' if my calculations are correct. I would be happy to go smaller but my 3db point happens at 20Hz which seems pretty good to me.

I'm going for mostly HT use in a room that is 1600 ft^3 now with a possible 850 to be added to that. The room is a rectangle with a small cutout on one side that could likely eventually be opened up to make the room bigger.

I was wondering what everyone else thinks of this. Also if someone knows where I can get the 15" for cheap I would be interested.

 

[TLS Guy]

I have been looking around at kits and other stuff and I saw that most people here did it with much simpler designs that the eD kit for instance. I have been reviewing posts and looking online. Since I'm most likely putting STs up front I'll have a good response down to about 40Hz or so. I'd like my sub to raise the SPL a little on the low end and go down low. So here was what I was thinking:

1. Ported design

2. I'd like to use the Audioplulse Axis 15" but this is the best I could find (little disappointed that it doesn't have the gorgeous blue finish) http://www.parts-express.com/pe/showdetl.cfm?Partnumber=293-618

Note: They have a Quad Voice coil but that just seems ridiculous all though it is the same price

3. I plan on using the EP2500 or EP3000 to power it (I'll have a lot more questions about this later)

When I used WinISD to model this sub I'm about 700% sure I did it wrong. I modeled it in a box that is 6.7 ft^3. But here is what I got:



That would be a box roughly 1.5'x1.5'x3' if my calculations are correct. I would be happy to go smaller but my 3db point happens at 20Hz which seems pretty good to me.

I'm going for mostly HT use in a room that is 1600 ft^3 now with a possible 850 to be added to that. The room is a rectangle with a small cutout on one side that could likely eventually be opened up to make the room bigger.

I was wondering what everyone else thinks of this. Also if someone knows where I can get the 15" for cheap I would be interested.

Apparently that driver is discontinued, and I can't locate a complete set of T/S parameters, just partial sets.

It seems the ongoing recession is taking out a lot of sub drivers, especially some useful ones, and the terrain is becoming littered with car thumpers.

If you are looking at driver in that price range and quality you need to be looking at the JL audio line.

 

[annunaki]

I modeled the Axis 12. Vented enclosures are just not practical with this driver.

Vented enclosure 2.5ft^3 net internal volume. Vent size 3.0"H x 20"W X 191.33" long. This tunes the enclosure to 18hz. Vent velocity is under 17m/s with 2000 watts rms. F3 is at 16hz and upper -3db point is at 101hz. This simulates 111db anechoic output at those -3db points.

Estimated external dimensions: 35.5"H x 21.5"W x 30.5"D It is huge!

Essentially one must build an 11.4ft^3 enclosure to house the vent since it displaces a whopping 8.03ft^3 of volume!! This is essentially a folded horn more or less.

I am sure it would be a beast with output, how does one fit it in most rooms without it being the focal point?

 

[BigSkreen]

I modeled the Axis 12. Vented enclosures are just not practical with this driver.

Vented enclosure 2.5ft^3 net internal volume. Vent size 3.0"H x 20"W X 191.33" long. This tunes the enclosure to 18hz. Vent velocity is under 17m/s with 2000 watts rms. F3 is at 16hz and upper -3db point is at 101hz. This simulates 111db anechoic output at those -3db points.

Estimated external dimensions: 35.5"H x 21.5"W x 30.5"D It is huge!

Essentially one must build an 11.4ft^3 enclosure to house the vent since it displaces a whopping 8.03ft^3 of volume!! This is essentially a folded horn more or less.

I am sure it would be a beast with output, how does one fit it in most rooms without it being the focal point?

When I modeled it with the optimal option the F3 was at 12Hz but the box was 48ft^3 I was seeing some crazy vent calculations but I was hoping that was me.

I really liked the Audiopulse/TC Sounds drivers and heard a lot of good things about builds that used them. Maybe I'll have to start looking at another manufacturer. Maybe I can go vented with a smaller box and make that up on power.

 

[annunaki]

When I modeled it with the optimal option the F3 was at 12Hz but the box was 48ft^3 I was seeing some crazy vent calculations but I was hoping that was me.

I really liked the Audiopulse/TC Sounds drivers and heard a lot of good things about builds that used them. Maybe I'll have to start looking at another manufacturer. Maybe I can go vented with a smaller box and make that up on power.

One can but then you have to worry about the driver exceeding xmax at as high as 40hz.

Either the driver has some incorrect parameters which causes it to model VERY Poorly, or this was a poorly designed driver. I seriously hope the former (especially for the price).

 

[BigSkreen]

One can but then you have to worry about the driver exceeding xmax at as high as 40hz.

Either the driver has some incorrect parameters which causes it to model VERY Poorly, or this was a poorly designed driver. I seriously hope the former (especially for the price).

Any suggestions on a better modeling driver? I've heard mostly of the TC Sounds, JL Audio, and Dayton drivers. I would appreciate any suggestions.

 

[TLS Guy]

Any suggestions on a better modeling driver? I've heard mostly of the TC Sounds, JL Audio, and Dayton drivers. I would appreciate any suggestions.

I have modeled a bunch of drivers to help people out and you now have a potpourri of drivers here.

 

[BigSkreen]

Once I pick my driver and I can model it out and get a box size does it matter how it is shaped? Am I mostly looking to build it within the dimensions for instance 5^ft. I'm not talking something extreme here like 6" deep or anything.

Also how does the internal bracing affect the sound. Do most people worry about it besides the stiffness of the box? Do I need to account for it in my space calculations.

I'm hoping this doesn't have to be an exact science because that is what lead me to believe I could make my own sub in the first place.

 

[TLS Guy]

Once I pick my driver and I can model it out and get a box size does it matter how it is shaped? Am I mostly looking to build it within the dimensions for instance 5^ft. I'm not talking something extreme here like 6" deep or anything.

Also how does the internal bracing affect the sound. Do most people worry about it besides the stiffness of the box? Do I need to account for it in my space calculations.

I'm hoping this doesn't have to be an exact science because that is what lead me to believe I could make my own sub in the first place.

Yes, it is an exact science. Miss alignments seriously impair the results. Bracing is essential and you have to add the volume of bracing to Vb to come up with Vt. You also need to add driver displacement and the amp. In my posts the damping material volume is included in the calculation.

Make sure you calculate vent air velocity correctly, other wise you will have a big problem. Keep it around 18 m/sec or under.

Before you cut boards, have us check you calculations.

 

[ParadigmDawg]

The AXIS is easily as good as JL

If you are looking at driver in that price range and quality you need to be looking at the JL audio line.

 

[BigSkreen]

I've found some TC Sounds subs just rebranded.

http://www.soundsplinter.com/rls12_subwoofer_information.html (via WmAx)

 

[WmAx]

I've found some TC Sounds subs just rebranded.

http://www.soundsplinter.com/rls12_subwoofer_information.html (via WmAx)

Yes, this is TC Sounds LMS Ultra re-branded. Price is great for the product you are purchasing. Extreme power handling paired with the most linear motor technology in existence, with 38mm one way linear excursion, certainly makes these drivers suitable for sealed if you have enough clean power for them.

They are suited to sealed, actually and with the high Qts, you need MUST use something like the DCX2496 to re-shape the response to be flat/smooth in a reasonably sized sealed cabinet. The 12" seems to do great in 4 cubic feet sealed and the 15" in 5 cubic feet sealed, each using 2 correction parametric bands for each driver. You will need to use a very high powered amplifier such as the Behringer EP2500 or comparable. You can also go ported. These drivers have odd looking T/S parameters - but they still work properly with the aid of some DSP processing.

-Chris

 

[BigSkreen]

I put my order in for the 12". I was planning powering it with the EP2000 or the EP4000 and adding the DSP.

I'll decide on the box by the time I get the sub but I'll probably stay sealed since I want to keep it around 5^ft.

 

[WmAx]

I put my order in for the 12". I was planning powering it with the EP2000 or the EP4000 and adding the DSP.

I'll decide on the box by the time I get the sub but I'll probably stay sealed since I want to keep it around 5^ft.

No reason to go ported on these, actually. As for the dsp-- it's not optional. You literally can not use this sub without the DSP - or it will have massively peaky/resonant output in the sealed box and will sound like crud

Using this sealed, with the EP2500 and DCX2496 DSP, this should give you SQ of the highest possible caliber. SPL should cleanly exceed for example, the JL Fathom F113 by at least 50%, due to the increased thermal power handling and increased linear excursion - and factoring the motor strength (BL) remains almost perfectly constant throughout the entire excursion path - unlike the more conventional motors systems such as on the JL W7.

Even so, it will be beneficial to add a 2nd sub later on - to have one in both right and left side of room, to give perfect integration with the mains and to relieve mains of LF duties - crossing around 80Hz eventually when you get the 2nd unit. Try to cross at 50Hz if only having 1 sub.

-Chris

 

[BigSkreen]

I found the EP4000 for roughly $75 more than the EP2000. Assuming that I want to add another sub in the future would it make more sense to just upgrade the amp now so I can run 1x2000w then in the future use the 2nd channel?

Should I be concerned about power draw? I haven't found any statics but 2kW and 4kW are a lot of power for a home.

 

[highfigh]

I am sure it would be a beast with output, how does one fit it in most rooms without it being the focal point?

Make it look like a fireplace?

 

[WmAx]

I found the EP4000 for roughly $75 more than the EP2000. Assuming that I want to add another sub in the future would it make more sense to just upgrade the amp now so I can run 1x2000w then in the future use the 2nd channel?

Should I be concerned about power draw? I haven't found any statics but 2kW and 4kW are a lot of power for a home.

The EP4000 is the EP2500, re-labeled for the new model run, so it has identical power production. You really need to have one of these amp dedicated per LMS driver. They will take every single watt a bridged EP2500 can produce and then some....

-Chris

 

[TLS Guy]

The EP4000 is the EP2500, re-labeled for the new model run, so it has identical power production. You really need to have one of these amp dedicated per LMS driver. They will take every single watt a bridged EP2500 can produce and then some....

-Chris

That really is a use of extreme brute force and not a very elegant design. It certainly does not fit my design philosophy, but I guess to each his own.

 

[BigSkreen]

The bigger hammer

HA. I have never been accused of being elegant that is for sure. I'm more often a brute force and ignorance type of guy.

 

[TLS Guy]

HA. I have never been accused of being elegant that is for sure. I'm more often a brute force and ignorance type of guy.

Then that's your baby! I hope you have a good electrician on hand to get enough power to where you will need it.