Building a Subwoofer

[dem beats 1,223]

I think that looks like one heck of a subwoofer.

What tune will hit have?

[my_first_account 0]

It will have a tune of 17.89hz due to the triple 4 inch ports that are 41.75in long each. If I can figure out a space for it, I could possibly go for 12 cu.ft tuned to 11.57hz with two 4 inch ports 39.5 inches long each. But, depending on the price and performance of the Gen 2 Tempest-X, I might go for that one though. I found a Gen. 1 for sale brand new for $188 on HTS, but I am going to wait to see the Gen.2 first.

Thanks for the help. And, sorry for the endless questions that ammounted to 16 pages.

[dem beats 1,223]

Lolz

I thought you were gonna save for the IXL 18"?

[my_first_account 0]

I am, but if the Tempest-X Gen 2 models better, and is cheaper enough, I will probably get that, but I will keep deciding and thinking .

Thanks for all of the help.

[dem beats 1,223]

NP. keep us posted!

[my_first_account 0]

Ok, will do

I'm going out of town today, so I won't be on until Monday. See ya then!!

[my_first_account 0]

Actually, I have changed my design on the ports. It will be one six inch port 33.5 inches long with two flared ends. Here's what I am going to get:

One http://www.thrilleraudio.com/detail.aspx?ID=536 (2 flares, 2 rings, 1 tube)

Two Extra http://www.thrilleraudio.com/detail.aspx?ID=533

Two extra http://www.thrilleraudio.com/detail.aspx?ID=532

Thanks for the help guys. It's greatly appreciated

Edited June 2, 2009 by my_first_account

[ABXX49 20]

Any updates on this?

[my_first_account 0]

Yes, I have the box plans drawn out, and will hopefully be getting the MDF by next week to start cutting. But, the IXL 18.2.2 sill isn't back in stock. I have changed my port plans again to save around $65, which is nice for me. The port will be 53 inches long.

Here is a sketch of what I have planned. I already have the cutouts planned, so that is nice.

Any suggestions are welcome, although nothing too crazy...lol

[Robert_J 0]

I've been away for a while and come back to a 16 page thread. Woohooo a build thread. WRONG.

I have read to stay away from the Behringer rack mounts though. They do their job, but I guess a lot of people have problems with noise and have to buy a BFD. I also read they don't do rated power.

What I read and heard, not my personal experience.

As one use uses a Behringer EP-2500 and BFD, I have no problems. It does rated power which is 1,200w @ 1khz. At 20hz, it puts out 800w @ 2 ohms. Those numbers are not in the manual and were determined by the guys at AVS. The noise part is the fan. If you have it in your listening room, then a $10 replacement fan and 20 minutes will cure that problem. Some receivers have low voltage out of the LFE jack so a BFD can add a little bit of gain but it is mostly used for its parametric EQ and flattening the sub's in-room response. If you have very low voltage there are a couple of additional pieces of equipment you can add to compensate.

To the OP, I see that you mentioned your parents being upset with your current sub. I don't think you know what you are planning with your new sub. I have over 5,000 square feet of concrete as part of my house's foundation and I can make every part of it vibrate with my EP-2500 and a pair of 15" TC-3000's. I've had my wife come into the theater room and I think she was screaming at me to turn it down. At least if I read lips I could understand her. The combination of extremely low bass and moderate SPL in a house is not a good combination if you have expensive or sentimental knick-knacks. Anthing not securely fastened will move.

-Robert

[ABXX49 20]

I've read wrong. I trust Robert, as I believe it was him who helped me with my HT subwoofer. Trust this man.

[my_first_account 0]

I've been away for a while and come back to a 16 page thread. Woohooo a build thread. WRONG.

I have read to stay away from the Behringer rack mounts though. They do their job, but I guess a lot of people have problems with noise and have to buy a BFD. I also read they don't do rated power.

What I read and heard, not my personal experience.

As one use uses a Behringer EP-2500 and BFD, I have no problems. It does rated power which is 1,200w @ 1khz. At 20hz, it puts out 800w @ 2 ohms. Those numbers are not in the manual and were determined by the guys at AVS. The noise part is the fan. If you have it in your listening room, then a $10 replacement fan and 20 minutes will cure that problem. Some receivers have low voltage out of the LFE jack so a BFD can add a little bit of gain but it is mostly used for its parametric EQ and flattening the sub's in-room response. If you have very low voltage there are a couple of additional pieces of equipment you can add to compensate.

To the OP, I see that you mentioned your parents being upset with your current sub. I don't think you know what you are planning with your new sub. I have over 5,000 square feet of concrete as part of my house's foundation and I can make every part of it vibrate with my EP-2500 and a pair of 15" TC-3000's. I've had my wife come into the theater room and I think she was screaming at me to turn it down. At least if I read lips I could understand her. The combination of extremely low bass and moderate SPL in a house is not a good combination if you have expensive or sentimental knick-knacks. Anthing not securely fastened will move.

-Robert

The fan mod is the only thing that I don't like about the EP2500. Would I need a BFD, or could I just use the EP2500 hooked up to my recever? I have also looked at the Crown XLS 802D found here:

http://www.audiolines.com/product.php?productid=17288

I would have to get te "Demo/Open Box" opion, becuase I absolutely can not spend $600 on a amp alone, and if the XLS arrives broken, I will send it in as many times as I have to until I get a new one. For me, doing that is worth the saved money. Would I need anything to boost the "Pre-Out" signal from my receiver for the Crown or EP2500?

Thanks for the help everyone. Sorry that this has turned out to be such a long thread, and I am grateful that you guys have not closed it yet...

[Robert_J 0]

You will have the fan issue with most pro amps unless you go with the Crown K series but even open box, scratch and dent, last year's model, etc won't help your budget.

Like I said, I used the BFD to tame my sub's in-room response. TC-3K subs have a very large voice coil which means they have a very high inductance. My sub sounded terrible. So I measured the response with an SPL meter and test tones. I had an inductance hump in the response of almost 15db at 54hz. I also had some room induced issues a little lower and a gradual roll off. I cut the peaks on my response and boosted the low end. I now have a flat respnse from 80hz to 17hz plus or minus 3db. Based on published responses, I can outperform a JL Audio Gotham home sub.

The Shiva-X and other XBL^2 subs will be low inductance subs so you won't need a BFD for that. But you still may have room induced peaks and valleys in your response. There is no way to really tell unless you measure. It cost me $40 for the meter. The test tones and Microsoft Excel spreadsheet (for graphing) were free.

If you want the BFD for some extra gain, then you need to get the amp first and check. I can't remember if it was Denon or Onkyo that had the low voltage LFE issue. My Pioneer VSX-1014 had no problem driving the EP-2500 with no other equipment.

-Robert

[my_first_account 0]

What kind of test tones did you use?

And, I will pick up a mic when I get the sub. Did you just get your from Radioshack or something similar?

I was also thinking about getting the Yamaha receiver found here: http://store.audioholics.com/product/2361/...CFRwDagodABpLow

That wouldn't be part of the sub budget, obviously.

Later on down the road, I am going to get the TriTrix kit on Parts-Express for front duties, and the Vifa 2nd Recession Busters Kit from Madiosound to handle the surround channels, and I am also thinking about getting the Vifa's for a center channel also. But, all this upgrading will be over a time period of somewhere around two and a half, to three years.

Thanks for all of the help guys. I would be nowhere if I hadn't came here and asked these questions.

[Robert_J 0]

I created sine wave test tones using a free tone generator I found on the net. My frequencies matched the PEQ spreadsheet. This spreadsheet is designed to be used with the Radio Shack SPL meter and the BFD. It's easy to graph your response. You can also model how a BFD will help flatten the response. After getting a simulated flat response in the software, I just copied the settings into the BFD. I re-measured and the predicted response was very, very close to the results.

If you want to go with a more automated system then Room EQ Wizard, a laptop, a calibrated mic and a MIDI connection is required. But you can make measurements and real-time adjustments to the BFD via a MIDI connection. If you have the hardware already, that's great. But a good external sound card starts at $100. A calibrated mic is $80. You may have to buy a mic pre-amp with a phantom power supply or get a pro-sumer USB sound card with this built in. M-Audio makes some nice ones.

If you go with the Tri-Trix speakers for the mains, you need to have a similar speaker for the center. You should not use a Vifa for a center. Your front 3 need to be timbre matched for seamless transitions across the front sound stage.

-Robert

[my_first_account 0]

I created sine wave test tones using a free tone generator I found on the net. My frequencies matched the PEQ spreadsheet. This spreadsheet is designed to be used with the Radio Shack SPL meter and the BFD. It's easy to graph your response. You can also model how a BFD will help flatten the response. After getting a simulated flat response in the software, I just copied the settings into the BFD. I re-measured and the predicted response was very, very close to the results.

If you want to go with a more automated system then Room EQ Wizard, a laptop, a calibrated mic and a MIDI connection is required. But you can make measurements and real-time adjustments to the BFD via a MIDI connection. If you have the hardware already, that's great. But a good external sound card starts at $100. A calibrated mic is $80. You may have to buy a mic pre-amp with a phantom power supply or get a pro-sumer USB sound card with this built in. M-Audio makes some nice ones.

If you go with the Tri-Trix speakers for the mains, you need to have a similar speaker for the center. You should not use a Vifa for a center. Your front 3 need to be timbre matched for seamless transitions across the front sound stage.

-Robert

OK, thanks for the help. I had forgotten about needing to get a new sound card for the mic and other stuff.

I know this is off topic, but what speakers would you recommend for the center channel? I would prefer a kit, that way I wouldn't have to worry about getting the needed materials, and putting together a crossover from scratch.

Thanks again for the help, Robert.

Edited June 24, 2009 by my_first_account

[Robert_J 0]

I'm using the Dayton III as a center right now and a pair of Dayton II's as mains. They will go back to their owner (a family member) very soon. I've got 3 DIII's in progress as well as a set of 7 Dayton Home Theater MTM's. The 5.25" Dayton Classic driver is supposed to have better mids than the 6.5" model used in the DII and DIII. I've only heard the DHT speaker once and it was great so I can't give a good comparison. Most of the published Dayton designs are better than any speaker you will get in a big box store. Use the same or similar designs across the front.

As for the measurment, the SPL meter and test tones is the cheapest route. Since the BFD is a set and forget piece of equipment I don't think the price of the extra equipment would be worth the one time use. None of my friends are this into audio so I couldn't even use it on their systems.

-Robert

[my_first_account 0]

I can't find the Dayton's that you are using. Can you give links to them? I checked Parts-Express for them, but couldn't find them. I haven't looked for the DHT MTM's yet, but will when I get a chance.

Thanks for the help

Edited June 25, 2009 by my_first_account

[Robert_J 0]

DII

DIII

DHT

All of the above were designed by Wayne J (aka The Reverend) - Speakerbuilder dot Net

Other designs that Wayne helped with:

DHT MTM

D8

Dave has similar designs - link

-Robert

[BigCProductions99 21]

Damn, Been A While Since I Checked In Here, And I'm Also Planning A H/T System For Later On Now.

How's The Building/Graphing/Searching/Question Asking/Mind Changing Thing Going So Far?

[my_first_account 0]

The box building will be started very soon. My Uncle will be getting the wood for me, and will be building it, so whenever he gets a chance from work, the box will be built.

I see that on Mach 5's website that the IXL 18.2.2 isn't there anymore. I also can't find the IXL 18 on SSA's store. Did they stop carrying it, or can I just not find it?

When I get the money, I willl start the surrounds and the front projects and building.

Thanks for the help everyone.

[Mike P. 0]

The IXL 18.2.2 will be available soon.

[my_first_account 0]

OK, but will SSA be carrying it? I will email them unless someone already knows the answer.

Thanks

Edit: I found it in their store. I was just not looking in the right place. Lol

Edited July 2, 2009 by my_first_account

[my_first_account 0]

Ok, a few change in plans. I decided to get the Mal-X becuase it would be almost as good as two IXL 18.2.2's, and it would be around $100 cheaper. Also, there won't be any way that I could harm the Mal-X with my 150w amp just in case it has no HPF on it.

A few build pictures:

My Uncle and I have started working on my box. It will be around 7.6-7.8 cu.ft after bracing and everything is accounted for. There aren't many pictures becuase it is only about half way done. I will hopefully be getting more before it is done, and with the driver installed and in my room.

The box dimmensions are 48" tall and 20" deep and wide. We will have two window pane style braces. One near the top of the port about 2 inches away, and one about 5 inches above the driver. We will be runing a strip of thin wood between these two braces to help keep those braces "braced." lol.

The port is 18.50 inches wide, 2 inches tall, and 55 inches long. The length is divded into two parts, one 34 inches long, and another is 17 inches. There is a 45 degee piece of MDF that will go between these two pieces of wood which will keep the port at two inches from the back wall; I don't remember how long that one was though. There is also another 45 degree piece of MDF that is on the bottom of the port so that it will have better air flow. That also was cut the right length to keep the two inch spacing correct.

Drawing everything out first:

The cut outs ready for nailing and gluing:

The 45 degree angle for 17 inch part of the port:

Don't remember what this one was for, just looks like another cut out picture:

Assemblig the slot port:

Roundover on the top of the port:

Port exit. The lighter piece of wood is for a better screwing place for the front pannel, as it will be just screwed on so it will be easier to maintain if needed. I will make sure that the holes will be pre-drilled so the wood won't split, although I am pretty sure my Uncle already knows this becuase he is a very experienced wood worker.

The port exit will have a roundover to help with chuffing and port noise.

A quick look at a Ford Ranger Pre-Runner by my house. They have around $150,000 tied up in that easily.

Not much progress but some. Hopefully, I will have it finished by this Wednesday ot Thursday. I got my Mal-X yesterday. Can't wait to get back home to it lol :mooooh:

There is one neat thing that we will be doing for this box. Since the Mal-X wieghs in around 50 pounds we will be taking 1/2 inch steel and making a mounting ring that will go on the inside of the box, right where the mounting screws will be, so the screws have extra strength to support that weight. Hopefully, we will have it done, but my Uncle is really busy and might not be able to get that finished. We might be spraying on a bed liner to protect the box, but I will have to see how much it is first. Otherwise, I will just go with Flat Black. It will have a small roundover on all outside edges of the box to keep it from splintering if it hits a wall, of something, and it just looks better to boot.

Special thanks to everyone that has helped me in my theads. You guys have been a great help.

Any questions or comments are welcome.

That's about it for now. More to come later. :bigsmile:

[topgun 262]

Looking good, but if you would like to save yourself a lot of time and effort, you can just double or triple layer the front baffle instead of using steel.