Robert_J

The 12 spoke 8" basket will be this one - link. -Robert

http://www.lorentz-audio.com/speakerbaskets.html Take a look at the model numbers for the 4 spoke and 12 spoke basket. Click the search button on the left and put in "speaker basket". Now you have a complete list of baskets. The baskets ending in 89 are 4 spoke and the baskets ending in 94 are 12 spoke. -Robert

A TC9 motor will work since it is 7". The TC7 motor that came with my blown sub is 5 7/8".

Others didn't mention it but that peak could be an 'inductance hump' in the frequency response. The driver's voice coil inductance is not listed on the Fi site but it is a common problem on high excursion, overhung drivers. I had a +10db peak at 55 hz with my TC-3000 subs. It is also a problem with the Dayton Titanic kits. That's why that amp has an internal jumper switch to counteract the hump. Check your owner's manual for Notch Filter Jumper. If you want to properly set up your PEQ, then you need to measure the in-room response of your sub. All you need is a disc with proper test tones and a Radio Shack SPL meter. You can go more elaborate with an RTA but that costs a LOT more money to do it properly. It takes about an hour to measure the different tones and enter them into a free spreadsheet that will compensate for the uncalibrated meter and give you a response graph. The spreadsheet I use simulates a Behringer Feedback Destroyer with 12 bands of PEQ. To simulate changes, you would only use 1 band of EQ. -Robert

Since no one answered, I'll give it a shot. That is your problem. You are playing below the tuning frequency of the enclosure. The sub acts as if it is in no enclosure below Fb. Power handling is thermal rating only. That is how much power the sub can handle before the voice coil melts. It is independent of frequency. Mechanical power handling is never mentioned because it is dependent on enclosure size/design and the frequency of the material being sent to the sub. Yes, stiffer spiders would give you more mechanical power handling but they will also impact other Theile/Small parameters. Your Fs will go up. Your efficiency may go down. Your Vas will change.Best solution(s) - Lengthen the port to tune lower, use an SSF, lower the gains on your amp and quit listening to music with low bass in it. One or a combination of the above will fix your issue. -Robert

I finally got MS Excel installed and can run the Unibox spreadsheet. Modeling your driver and 2 PR's in an 85L (~3.5cf) box, I get a perfect EBS response graph when I add 1,000g of weight per PR. The Fb is lowered to 17hz. So a 15hz SSF would be a perfect match. At 500w, the driver is only hitting about 20mm of excursion max. The PR is reaching xmax at 15hz. Make sure that the PR's are on opposing sides of the box. 2,050g (4.4 pounds) is a LOT of weight to be moving back and forth. Having them on opposing sides will counteract each other so that the enclosure doesn't move at all. -Robert

Any company that does recones can sell you these. ED, Fi, Atomic, PAP or RU. -Robert

Start by reading Loudspeaker Design Cookbook by Vance Dickason and Testing Loudspeakers by Joe D'Appolito. These guys are icons in the loudspeaker world. Once the reading is done, then you need to buy appropriate hardware (calibrated mic and a quality sound card) and software (LSP CAD, LMS, etc). It's not cheap. If this is going to be a life long hobby, that's a small investment. If this a a 'test the waters' or a 'one time build' then stick with a proven design. HT Guide has a great DIY section of the forum. DIY Audio has a complete forum for speakers. PE Showcase has great designs. GR Research has some great kits. DIY Cable has kits. Madisound and Meniscus are two places that will design a crossover for a small fee when you buy the speakers and parts from them.-Robert

Measure out the weight, glue it one the back of the PR evenly. Washers, nickles, etc. Account for a few grams of glue as well. Or you can glue a large bolt into the cardboard "voice coil" of the PR. That will add some weight and allow you to add more as needed. http://www.oaudio.com/500W_SUBAMP.htmlThe PE BASH has infinite possibilities based on the values of 2 resistors that you replace. I know you mentioned 99% music. Wait until you watch a movie with a real sub. It is very addictive. My wife and I watched Transformers over the weekend. Average movie but both the visual and audio special effects were great. I'll re-watch it after I install my 18's in the home theater.-Robert

The 500w BASH amp from 0 Audio is another choice. But since it has an adjustable SSF, I would tune lower. You don't want an Fb of 22hz and an SSF at 16hz. The BASH from PE is another option as well but you have to replace 2 resistors to change the factory SSF. -Robert

If you are going to use the sub for action movies the other 1% of the time, then I suggest a plate amp with an SSF set at 18hz to 20hz. The 500w Dayton model from Parts Express would be perfect for this. It also has a one band parametric EQ that can help tame room response. The Fb in the low 20's seems right. -Robert

I thought about suggesting a pro amp as well but he needs something with an SSF. Unless he uses a Reckhorn crossover or an Elemental Designs EQ.2, a pro amp will play too low for a PR enclosure.-Robert

What's the Fb? What will this sub be used for, music, movies or both? Percentage of each? How big is the room it is going in? Not a good idea. You would spend more for a proper AC to DC power supply than you would for a plate amp.-Robert

It's a 2" coil and TC2+ motor. You have said in the past that you can recone these.-Robert

Now I know the specific TC9 motor you have. That is the wider gap with the extended pole piece. The same thing that I am using with Fi 18" recones. My kits came from Fi with 60mm long coils. There is more than enough room since the motor is 75mm deep.-Robert

What is a TC9+ motor? Is it any different from a regular TC9? What was the original driver? The reason I ask is that I have a bunch of TC9 motors that are mated with Fi recones. Most of my TC9 motors came from Elemental Designs E12.22 subs (the sticker is still on them). Dual 1" magnet slugs and an extended pole piece. The 3", 4 ohm coils from Fi fit perfectly. I have one TC9 motor that is a little odd. Even though it has dual 1" magnet slugs, the pole piece is not extended and the gap is smaller. I plan on reconing this as well but requesting a 4 layer voice coil instead of 6 or 8 layers. Basically, something that will give me more than 1mm of play between the VC and the top plate. -Robert

I would NOT put the plate amp on the bottom. Even though it does not have a heat sink on the outside, it does use the metal plate as one. The heat needs to be able to rise and that will not happen with the amp on the bottom. Mount it on the back like all other home theater sub manufacturers do. A cylinder is the most efficient way to create an opening with the least surface area. Does that matter with a port? Maybe if you are measuring with scientific grade tools but not your ears. We can get into a long debate about surface friction but I'm not up on my fluid dynamics research. Build a slot or square or even a pentagon shaped port. I would flare both ends though. Port noise is an issue and flares do help. www.subwoofer-builder.com has a bunch of info on flaring including info on flaring slot ports. As for the BFD being ugly, hide it. It is a set once and forget piece of equipment. I don't even think my wife has ever commented on a piece of gear other than when I get something new. I'll do the Price Is Right model hand move over it. She always replies with a fake "ooooo" "aaahhhh". I install it, program it into the Harmony remote and the system works as usual. That's what I did when I purchased an HDMI switch box. My wife did not need to know that I had switched my HR20 DVR from a component connection to an HDMI. She still hits the same button on the remote to watch it and it still works. Functionality is all that matters. As long as it integrates seamlessly into the sytem, I'm usually able to buy it. You can also look into the EQ.2 from ED. It looks more like a piece of stereo gear instead of pro gear. Check out www.svsound.com for a Radio Shack SPL meter. They carry them along with a tutorial on subwoofer setup. -Robert

I invested in a de-solderer from Rat Shack since I have to mod 3 NHT amps that do not have adjustable gains. Or you can just heat the solder and pull the resistor out with a pair of tweezers. Both ways are extremely easy. The amps come with a sheet that details what resistors are needed for boost/cut-off frequency. You can also view them on the PE site in case you need to order resistors. I like to set my SSF a few hz below the Fb. So a 12hz Fb with a 10hz SSF is OK. In fact, with margins of error, just getting close is OK.I've never been a fan of slot ports for many reasons. The biggest is just the finished look. Not a problem if the sub is in the trunk but if you have to look at it, the wife wants it finished. You don't see SVS, ED , Epik, Aerial Acoustics, Klipsch, Polk, etc using slot ports on their home subs. Also, using an Aeroport will allow multple tuning points. O Audio sells a BASH amp that has an adjustable SSF with settings at 15, 20 & 25 hz. You can easily recreate a multiple tune SVS sub. Just something to think about. The Dolby standards are 120db peaks at the seating position so the Shack meter is more than adequate. It has also been compared against a calibrated mic and the correction values are widely published. It makes using it for calibration very easy. The next step up is Room EQ Wizard (free) along with a mic (Shack SPL is acceptable) to adjust a Behringer Feedback Destroyer. The BFD gives you 12 bands of PEQ as wells memories so you can store different room curves for music or movies. Termlab may be good for SPL but you have no idea if the mic is calibrated flat or not. That may be more than enough information. You are starting off with an excellent driver and amp. Everything after this is just icing on the cake. Your proposed sub is already head and shoulders above anything available at Best Buy, Circuit City or any other big box store. -Robert

The BASH amp comes from PE with the subsonic filter set at close to 30hz. The Dayton amp has the SSF set at 18hz. Both are adjustable by changing resistors on the circuit board. You must de-solder/re-solder to complete this. So if that is beyond your capabilities, then don't tune that low. The Dayton amp has two nice features as well. There is a notch filter around 50hz that is used when paired with the Titanic sub in the kit. This filter will reduce the inductance hump in the response at around 50hz. It also has a one band parametric EQ. Those are very nice in taming the sub's in-room response. It does take some software and some hardware to properly measure your room and correctly set up the PEQ. Minimum requirement is a Radio Shack SPL meter (every home theater nut should own one) and spreadsheet software (Microsoft Excel is preferred due to the ability to run spreadsheet macros). 15 cf tuned to 20hz with 500w of power and an 18hz SSF looks very good when modeled in Unibox. I would use a pair of 4" Aeroports to keep the port noise to a minimum. -Robert

Posted YEARS ago by Dan Wiggins when the Brahma series came out. He said that it would perform just fine with a single magnet slug in the motor but no one would buy it based on his market research because the sub was "too small". From the uninformed comments I quoted, I guess he was correct. He went on to state that the extra slugs just added clearance for excursion while adding very little to the motor's power. The real increase in motor strength comes in larger diameter motors (just like Fi went to). They are getting their extra clearance for excursion via a very deep back plate. Very cool design but a short statement like mine above from someone official needs to go along with the sub to educate the uninformed. -Robert

Is this the OEM with the tall rubber surround and the carbon fiber/honeycomb cone? If so, I'd contact Patrick (robotunderground at yahoo dot com). He has some surplus TC Sounds parts so you can keep the TC Sounds look. I used his parts to build a 12" with the same type cone you have. Here's a slideshow of my build process - link. -Robert

Scroll through the AVS links I gave you. I did link to specific postings but that's a thread that is close to 20 pages of completed projects. Dozens of sonosub examples. Desiging one is just like designing a normal enclosure. Except the formula to find the enclosure volume is pi*r^2*height. Something you should have learned in 10th grade geometry. As for needing 500 or 750w for an IB, that may be too much depending on what frequency you are playing. The Fi Car Audio IB needs 500 to 600w to reach xmax at 20hz (link). If you were going to run without a subsonic filter and shoot for the single digit reponse, I wouldn't push more than 300 per driver. The EP-2500 has been measured at 800w/channel at 20hz at 2 ohms. That's my plan to power four 18" Fi/TC Sounds franken IB subs. -Robert

Depends on the what the sub surround it made from. I've done 4 recones with Fi parts and used Loc-Tite 50 minute epoxy. Scott recommended 20 minute but I couldn't find any and I was afraid that 20 minute wouldn't be enough. I did enough practice runs without glue that 20 minute would have been more than adequate. I recently built a custom sub from scratch using surplus TC Sounds parts. The high roll rubber surround allowed me to use E6000/Plumber's Goop to hold the surround and spiders to their respective landings. Since it wasn't a kit like from Fi, I used CA glue to hold the spiders and the cone to the voice coil. I thought about using Goop but the coil gets extremely hot and the Goop would have lost its strength. Here's a Photobucket slideshow of the build - link. -Robert

Parts Express, Madisound, O Audio, Rythmik Audio and Elemental Designs are all sources of good plate amps. Depending on the design, I would recommend a pro amp. I run a Behringer EP-2500 to power my 15" TC-3000's. We do this every day at the different home theater forums I frequent. The biggest issue is budget and how much real estate you are willing to give up. Don't expect gut wrenching bass from a .5 cubic foot box. Home theater requires much larger boxes to get the most out of them (Hoffman's Iron Law). You can build it to look like furniture. More furniture. But most just go for very large and hope it blends into the room - link. Here are some other designs.Now that you have an idea of what sizes you are dealing with, get a tape measure and find out how much space you can give up. Don't forget to measure vertically as well. Sonosubs take up less floor space but can go as high as 8 feet sometimes. Finally, what is your budget for driver, amp and construction? Depending on the room, you may not even have to give up any floor space. Can you go with an IB sub - link? Finally, just a pic of some good looking DIY speakers - link. -Robert