This one is for PMQ

[Looneybomber]

In my on going quest to reach 120db @ 20hz I did a little reseach tonight on 2 different subs. The Adire Tempest 15D4 and the Adire Maelstrom 18D4.In each test I set the power to 1000w being that I'll use a Crown K2 amp capable of delivering over 2000w.

This first one shows the SPL of a SINGLE Maelstrom 18" dual 4ohm. The reason I only picked one is because they MSRP at 499.99.

*edit* I can't actually see any of my attatchements, nor any others on the forum (I have no idea what's wrong with my computer), so if you post a picture, have it hosted somewhere else and use an IMG tag. That's the only way I can see pics
Modified by Looneybomber at 4:00 AM 7/25/2006

[Looneybomber]

And the group delay of that same sub.

[Looneybomber]

For the Tempest 15" dual 4ohm, I decided on 2 of them since they have an MSRP of 249.99. Half the price of the Maelstrom 18D4.

As you see I picked up a few db's at 20hz, but the box is also about 10^3 larger!

[Looneybomber]

As you can tell, the group delay is also a bit worse than the single 18D4.

The last thing for me to think about, which WinISD doesn't measure, is power compression. Will these drivers actually perform that well at those low frequencies with that much power. I am imagining a 6db/oct slope at around 40-45hz @ 1000w's. This quest for big bass down low I think will end up costing TOO much money. More than likely I would need 4 of these Tempest drivers

With the Maelstrom 18D4, it's rated to 1000w so I would use the smaller Crown K1 amp to save money and not run the risk of accidently overpowering it and blowing it or melting the VC.

Another thing worth noting about the Maelstrom. If I use a 10ft box instead of 6.5ft and tune it to 16hz, I pick up 2 db's at 20hz, but my group delay goes to 36.5ms @ 17-18hz.

[Looneybomber]

Wait I lied. I tried the Ascendant Audio Arsenal 15. With 1000w in a 34ft^3 box!? I can hit 120db @ 17hz! A group delay of 58.37ms @ 15.48hz On the bright side that is pretty deep down though. On the sucky side that box is going to be HUGE!!!

*edit* This is for 2 subs.
Modified by Looneybomber at 5:59 AM 8/2/2006

[MinisterofDOOM]

*edit* I can't actually see any of my attatchements, nor any others on the forum (I have no idea what's wrong with my computer), so if you post a picture, have it hosted somewhere else and use an IMG tag. That's the only way I can see pics *edit* I can't actually see any of my attatchements, nor any others on the forum (I have no idea what's wrong with my computer), so if you post a picture, have it hosted somewhere else and use an IMG tag. That's the only way I can see pics

Nothing useful to add audio-wise, but I'm betting the reason attachments don't show is because you've accidentally blocked images from forums.nicoclub.com in your browser. Right click on any of the image placeholders and make sure that "Block Images from forums.nicoclub.com" is unchecked.

[audtatious]

Is this in a house or car? If in a car, does the program include in-cabin compensation (doubtful)? In-car dynamics will be higher as a lot of these programs only show 1/2 axis response without the boost of the actual cabin itself. Throw the sub in a car and you are usually at 1/4 axis and +3db, not including any additional loading or boundry effects. I believe the general "rule of thumb" is +7-12db > program charts when the sub is installed properly in a car.

[Looneybomber]

Right click on any of the image placeholders and make sure that "Block Images from forums.nicoclub.com" is unchecked.

I never saw the "block images" option anywhere.

Is this in a house or car?

Nope, In a house. There isn't a home theater forum so I am using this one out of context.

[Looneybomber]

Well in order to fit these subs in 17.5^3 ft. enclosures, I came up with an idea. Use them as the base of an entertainment center. The subs would be rear firing and side ported. Each sub would have its own enclosure that will be put together as the base for the TV to sit on.

This entertainment center will be nearly 26" deep, over 5ft high and around 9.5ft wide. It will hold 6 pieces of electronics (sub amp, receiver, DVD player, VCR and 2 more things), and store a few DVD's. To make it somewhat manageable with it's overwhelming size and weight, it will be in 5 pieces; 2 sub boxes, 2 side peices and a top piece. All the pieces will bolt together with thin sheets of rubber or felt between them for secure assembly and rattle free performance, with the exception of the sub boxes which will not bolt together.

There will be 2 sides to this entertainment center. On the left will be a door that will open, allowing you to store DVDs on the door and inside the cubby hole. On the right will be the "amp rack" with all the electronics and 3, 120mm fans blowing hot air out the back. They will be hooked up to a 3 stage thermostat which will turn them on low, medium and then high as the temp inside rises. 3 more holes will be cut at the bottom rear of the amp rack to suck in cool air. As an added form of user friendliness, the rear panel will also be bolted on to give access to all the electronics when wiring them up. Along all the edges of that panel will be more felt to keep from rattling. The front door of the amp rack might be solid wood, or it might be glassed in the middle to allow IR remotes to work.

The last peice will be a board the length and depth of the entertainment center that will bolt to the DVD rack and amp rack. You will now have a 9.5x2ft top on which you can put your center channel and anything else you might want.

The total weight for this will be around 450-500lbs with the two sub enclosures comprising more than half of that weight (150lbs each). They will both be made of light weight 1" MDF as opposed to regular weight MDF which will save nearly 70lbs per enclosure. I will use a white ash veneer on the two enclosures and either 3/4" white ash boards on the rest of it, or veneered MDF. I've also thought about using maple or beech. I like light woods.

Cost? 500.00 for the subs and around 700.00 for the amp used on eBay. As for the wood...3-400? I honestly have no idea, plus I do not have large enough table saws to tackle this project right now. Oh well, it gives me something to think about at work when I decide to kill time since I can't actually build this.

As you see in the picture, there is no internal bracing in the enclosures. That's because I suck at MS paint and didn't even attempt at trying to draw them in. They will be placed where the ports terminate and will also act as supports for the ports since they will be glued into the bracing.

[PoorManQ45]

Sorry it's taken so long for me to notice this thread. I've been busy with work.

Looney: I notice you're in Kansas.

Do you have a basement and/or cellar below the home theater room?

If so you You can do two things, 1: Make a box and put it in th ebasement and cut a hole in the floor to allow the driver to interact with the theater room(put like a nie grate or something on it).

2: Make the box between two of the subfloor beams and just attach it to the floor. You won't feel the actually air pressure, but everything will shake like hell.

I suspect you can't do eithe rof these though, so regular box is what you're stuck with. Now, you could use Sonotube.

It'd have to be pretty tall and atleast 18"(maybe 24") wide but it'd be really easy.

The entertainment center Idea is ok, but you're going to kill whatever TV goes in it from all the vibration.

Note: WinISD does indeed show power compression.

Here is the graph, green = Tempest(x2), Red = Maelstrom, Gray = Dayton MkIII.

[PoorManQ45]

See how all of the graphs have that dip in them?

That is considered compression.

To figure out how much power you can feed these drivers before this occurs what you do is go to the "maximum power" screen. THere will be a dip just like in the SPL. Click on the lowest point of the dip and this will tell you the power.

Then you take this number and go back to the regular SPL screen(not maximum SPL) and enter this amount of power in the "signal" tab in the box with your current project info.

This will show you the real frequency response before compression.

I'll do that in a second

[PoorManQ45]

I wouldn't recommend the Maelstrom at all. The frequency response is horrible.

I like the tempest, or the dayton MkIII.

[PoorManQ45]

Ut oh looney:

It seems two of the Dayton MkIII may be a better choice then two of the tempests.

The frequency response is flatter, the box is smaller, SPL is about the same

[Looneybomber]

I suspect you can't do eithe rof these though, so regular box is what you're stuck with. Now, you could use Sonotube.

It'd have to be pretty tall and atleast 18"(maybe 24") wide but it'd be really easy.

The entertainment center Idea is ok, but you're going to kill whatever TV goes in it from all the vibration.

I've heard that term "sonotube" but have never researched it before. Is it just your normal tube. If so, how do you build one?

As for the TV I was thinking of using a glass top suspended by rubber bumbers to help absorb the vibrations. I was hoping a combination of that, plus nearly 300lbs worth of MDF in the enclosures would absorb most all vibrations.

Anyway, this is all just ideas right now since I do not have large enough equipment to build an entertainment center.

[PoorManQ45]

I've heard that term "sonotube" but have never researched it before. Is it just your normal tube. If so, how do you build one?

Have you ever seen those round columns on the entrance way of buildings/houses? Those are made with sono-tube. What they do is get the right diameter, length, and design(flat of corrugated) and then just brace it up and then fill it with concrete. After a day or two they cut the thing off.

What you do when building a sub with it is get a tube of appropriate diameter and length. Use the standard volume formula for a cylinder to figure out what sizes.

For the ends it's pretty common for people to use two pieces of MDF(3/4" or 1", your choice). What you do is cut one piece like 1/16~1/8" smaller then the inside diameter of the tube. Then you cut the other one either exactly the outside diameter of the tube, or one inch larger. Then you fasten these two pieces together(i'd use a compass or something to mark the centers) with interior/exterior "tite bond" wood glue. Don't try to use liquid nails as it is too thick.

Once the glue has hardened use your plung router to cut the hole for the driver and the amplifier(assuming plate amp) and for the ports is vented.

Then you're good to go. You can finished the outside of it with some cloth that you wrap around it, or veneer.

[Looneybomber]

Isn't that stuff made of cardboard? If it's the same stuff I am thinking of, it's like 1/4" thick kraft paper right? I don't know about that. What kind of sound deadening properties does it have? Like how will it compare to 1" MDF

PS I think you're using a different version of Win ISD than I am.

[PoorManQ45]

PS I think you're using a different version of Win ISD than I am.

I'm using the pro version

Isn't that stuff made of cardboard? If it's the same stuff I am thinking of, it's like 1/4" thick kraft paper right? I don't know about that. What kind of sound deadening properties does it have? Like how will it compare to 1" MDF

Well, the biggest problem you have to overcome with any sub box is expansion and/or contraction. A cylinder inherently minimizes this. Unless you actually jump on th edamn thing it is not going to expand and/or contract.

It is closer to 1/2" thick.

Found sound deadning it's recommended that you just use like R19 fiberglass on the walls.

[PoorManQ45]

Looney: I'm entering more drivers into WinISD.

I think I found one that you'll love. It won't hit 120dB anechoic, but it will be able to do it in a room.

The driver is an Adire Audio Tumult 12D2

This driver in a 2.5ft^3 tuned to 19hz yields a very flat response.

Or you could go with the Tumult 15D2 in a 6.75ft^3 tuned to 18.50

Here's a picture. Red = 15D2, Blue = 12D2.

[PoorManQ45]

For a really crazy loud sub try two Adire Audio Tumult 18D2s in a 12ft^3 sealed box.

The output peaks just a hair shy of 140dB at 72hz.

At 20hz it's at 119dB. What's crazy is that at 3.95hz the output is 90dB!

That's insane.

[nismofly]

lol wire a kick drum to your sub signal

thatll make it louder than a sub for sure

[PoorManQ45]

LOL. SOunds like you've tried this before

[ddrumman]

LOL. SOunds like you've tried this before

So did you get the email?

[Looneybomber]

Looney: I'm entering more drivers into WinISD.

I think I found one that you'll love. It won't hit 120dB anechoic, but it will be able to do it in a room.

The driver is an Adire Audio Tumult 12D2

This driver in a 2.5ft^3 tuned to 19hz yields a very flat response.

Or you could go with the Tumult 15D2 in a 6.75ft^3 tuned to 18.50

Here's a picture. Red = 15D2, Blue = 12D2.

Nice, too bad those speakers are so expensive for a paper cone and foam surround! I was hoping Elemental Designs had out a good speaker at a good price, but nothing they have will go as deep as I would like. They do have a small 6" sub that I want to use for a fiberglass stealth install in my explorer...4 of them if they'll fit. I have to pull the rear panels off to see if they'll fit.http://www.edesignaudio.com/pr...r=USD

The options you mentioned wont be quite as deep as that Arsenal15, but that thing requires 17ft^3!

Another thing worth mentioning. To hit 120db @ 20 hz will be awesome! To be equally as awesome, I need full range speakers that will also play to 125'ish db's. That will require a pair of speaker with a 1w/m sensitivity of about 100db's (assuming 140w/channel that my receiver puts out in stereo). What would that require? How about some old Klipsch KLF-20's? Though I am not a fan of horn tweeters.http://www.klipsch.com/product...specs

I could even get by just fine with some RF-3II'shttp://www.klipsch.com/product...specs

Or a cheaper route with the Synergy serieshttp://www.klipsch.com/product...specs

Or even another pair of Cerwin Vega's, but the whole purpose of this awesome sub was to reinforce an awesome home theater as well as "rock the house" during parties. Cerwin Vega is not exactly awesome for HT use due to their lack of sound quality. My Infinity's are much better and they're just Entra1 bookshelfs.
Modified by Looneybomber at 5:11 AM 8/11/2006

[PoorManQ45]

Looney: Remember that our ears are less sensitive to bass.

If the midrange is at 90dBs then at 20hz you have to be at 120dBs to get the equivolent loudness.

So theoretically you'll only have to be able to hit ~110dBs with your mains.

I know that driver I posted is expensive, but that's pretty cool for a small enclousre. But for that price you could go with SVS

[Looneybomber]

Looney: Remember that our ears are less sensitive to bass.

If the midrange is at 90dBs then at 20hz you have to be at 120dBs to get the equivolent loudness.

I know, but up around 45-70Hz where the sub will not be excursion limited, it will play louder than 120db. Depending on the setup, possibly even as high as 130db, thus the reason I mentioned my mains being able to play 125db...Which in all honesty is REDICULOUS for a home stereo/theater!!!

I know that driver I posted is expensive, but that's pretty cool for a small enclousre. But for that price you could go with SVS

You're right, that is pretty awesome for a small enclosure (Tumult 12). As for SVS, I'd like to see how they perform SPL wise because I already know they can play deep.

[PoorManQ45]

You're right, that is pretty awesome for a small enclosure (Tumult 12). As for SVS, I'd like to see how they perform SPL wise because I already know they can play deep.

Yeah, unfortunately I don't have any T/S specs to do an apples to apples comparison.

There are frequency response vs. SPL charts for most of the SVS line on the 'Net though.

Do a little googling

[Looneybomber]

There are frequency response vs. SPL charts for most of the SVS line on the 'Net though.

Do a little googling

Here is one picture I found on AVSforum.comPB-10 using a quick sweep.Actual compression #'s using sine wave testing.Quote »20 Hz: 93.9 dB (8.0 % - amplifier limited)22 Hz: 96.9 dB (2.7 % - amplifier limited) 25 Hz: 102.2 dB 32 Hz: 104.1 dB40 Hz: 105.8 dB 50 Hz: 106.7 dB 63 Hz: 105.7 dB 80 Hz: 104.0 dB [/quote]