Sub Options for TC12

[PoorboyMike]

My original plan was to put THIS driver in a ~2 cu.ft. sealed box powered by a 500w Bash amp. I'm sure this would sound quite good, but then I started thinking of ways to up the output a little down low. The problem is, when I model this thing in a bigger box, tuned between 18-20 hz, I get a huge hump in the response around the tuning frequency. When I make it smaller the hump goes away but then the port becomes too long (4" PP) to fit in the box without putting a couple bends in it.

Does anyone have any experience with slot ports and would this even be doable with this driver? I don't really want to do passives unless somebody knows of a fairly inexpensive option that would work out. TCsounds is out of their passives right now. My main goal with this is to keep the size reasonable (under 3 cu.ft.) and have more output and/or sound much better than 12" commercial subs in the $5-700 range. I know a few people that would buy these, so I really want to build something with the least amount of compromises. I guess if that means keeping it sealed for high quality/smaller size, than that is what I will do. I would just like to hear some other opinions from the experts. ;x(

t/s params for TC12:

OEM overstock TC-12.
Black paper cone
1.5" wide NBR surround
28mm xmax
215 ounce motor
1200 watts RMS
3" wide, long-wind copper voice coil
Dual 10" nomex spiders with woven leads
Single 4 ohm DCR

TSP's

Qts 0.464
Qes 0.534
Qms 3.55
Fs 21Hz
Res 3.11 ohms
Ls 2.2 mH
Lp 5.1 mH
Rp 7.6 ohms
Dia 235mm
Vas 54 liters
Mms 347 grams
Cms 160 um/N
BL 16.5Tm
Spl 82dB

[PoorboyMike]

I forgot to mention, if I do go sealed, I plan on modifying the boost on the amp to give 5 db at 20 hz. Good idea or no? I think the factory setting is 3 db at around 30 hz, so I think I would want to change that regardless of weather I go sealed or ported/pr. The guy using this isn't going to want a seperate parametric eq. After all, he is using a Bose system right now and I don't think I could build something that would sound worse. 8O

And another person that is going to demo this has a Paradigm PDR12. Shouldn't be too hard to beat that I wouldn't think. :lol:

[jdb]

I picked up 2 of these. I finished a small (approx. 1.4ft^3) sealed box for one last night. I fed it 500 watts from one channel of a Soundcraftsmen RA7503 and it wanted a lot more. Even with your larger box, you might want to use a bigger amp.

I have been modeling them in a ported box also (tuned to 17 Hz). I know what you mean about port length :E. With an xmax of 28mm and a low tuning like that I wouldn't consider a 4" port even if it did fit. Right now I am looking at 5.3ft^3 with a folded slot port 3"x16"x(forgot the length-different computer). Basically the 5.3ft^3 box ends up being about 8.5ft^3 box with a port that shouldn't chuff much. If you have Autocad, I can send you a drawing.

[PoorboyMike]

How did the sealed one sound other wise? I'm assuming it still had
decent output?

[ThomasW]

Does anyone have any experience with slot ports and would this even be doable with this driver?

There's no magic involved in doing a slot port. It needs the same cross-section as a round one.

Some design links

http://www.darkscience.com.au/caraudiohowto/slotcalc/

http://www.carstereo.com/help2/Articles.cfm?id=31

Some slot port design basics

http://mobile.jlaudio.com/support_pages.php?page_id=165

[PoorboyMike]

There's no magic involved in doing a slot port. It needs the same cross-section as a round one.

Some design links

http://www.darkscience.com.au/caraudiohowto/slotcalc/

http://www.carstereo.com/help2/Articles.cfm?id=31

Some slot port design basics
http://mobile.jlaudio.com/support_pages.php?page_id=165

I guess I should have been more clear on the slot port. Staying under a 3 cu. ft. box to eliminate the spike at tuning frequency requires a very long port. It seems like I read about somebody saying they didn't really care for the sound out of a design like that. I just wanted to hear opinions from people who may have build similar designs using a rather long slot port.

[PoorboyMike]

I have been modeling them in a ported box also (tuned to 17 Hz). I know what you mean about port length :E. With an xmax of 28mm and a low tuning like that I wouldn't consider a 4" port even if it did fit. Right now I am looking at 5.3ft^3 with a folded slot port 3"x16"x(forgot the length-different computer). Basically the 5.3ft^3 box ends up being about 8.5ft^3 box with a port that shouldn't chuff much. If you have Autocad, I can send you a drawing.

No, I don't have Autocad. And I wouldn't mind a sub that size, but I don't think the average guy (married) would go for something like that. I appreciate the offer though.

[jdb]

How did the sealed one sound other wise? I'm assuming it still had
decent output?

Actually, SQ was alright, but as for output - I wasn't impressed.

I AB-ed it against my PB-10/ISD and my diy 15" Quatro/PE 250 watt plate amp in about 3.5 ft^3 sealed. I only used music as it wouldn't be fair to compare it against the PB-10 at 20 hz. I moved the subs around so that they were each in the same location when I listened. I made sure the receiver settings were the same. The PB-10 completely stomped the TC-12. The diy Quatro also had significantly more output. Keep in mind this is with less than half of the wattage the TC-12 can handle.

Another possible reason could be that I am feeding the RA7503 straight from my receiver (maybe a Cleanbox would help). I doubt that this is the case as the RA7503 has powered all of my other speakers with ease. Maybe tonight I will try the Soundcraftsmen connected to the high level inputs on the Quatro's plate amp and see if there is a difference. My bridge adaptor for the RA7503 is cracked and doesn't work, otherwise I would bridge it for more power. Since the box is relatively small, I might put it in a buddy's car (just for testing) and try it with his 1600 watt amp. I will keep you posted.

[---k---]

Is "completely stomped" just refering to output ability, or both that and sound quality. I would expect a small sealed to have a difficult time keeping up.

[WillyD]

The TC-12 should more than keep up with the Quatro, as long as you give it enough power.

When you say "I made sure the receiver settings were the same. " does that mean all of the level settings were equal? Did you attempt to level match the subs before 'testing'? If not, there is one of the problems.

[PoorboyMike]

Is "completely stomped" just refering to output ability, or both that and sound quality. I would expect a small sealed to have a difficult time keeping up.

I would think that a driver like this would be able to come close to the PB10 in a 2 ft^ box. Unibox shows 102 db at 20 hz with 500 w.

Maybe I'll just send the Bash amp back and pick up an EP1500 or a Buttkicker. I think my best bet here is to go sealed with this driver and if I want good output I'm going to need some horse power.

Unibox does show that 500w pushes the driver pretty close to Xmax at 15 hz or so (in a 2 ft^ box), but what is the likely hood of the Bash amp actually putting out 500w?

[jdb]

Is "completely stomped" just refering to output ability, or both that and sound quality. I would expect a small sealed to have a difficult time keeping up.

Just output, sound quality was fine.

The TC-12 should more than keep up with the Quatro, as long as you give it enough power.

When you say "I made sure the receiver settings were the same. " does that mean all of the level settings were equal? Did you attempt to level match the subs before 'testing'? If not, there is one of the problems.

No level matching, I just used equal settings on the receiver. I will do a search on level matching. I agree that this driver should more than keep up with the Quatro - I just thought it would do it with 500 watts. I still think one of the problems may be the signal into the amplifier.

[WillyD]

No level matching, I just used equal settings on the receiver.

Well then from the very start your comparison was flawed. The TC12 would have undoubtedly needed the levels turned up to match the level of the other subs, because it is less efficient than the sealed Quatro and the PB-10.

[jdb]

Hey PoorboyMike, any progress, updates?

[PoorboyMike]

Hey PoorboyMike, any progress, updates?

I finished the rough in and am giving it a test run now. It sounds pretty darn good but I don't think the 500w bash is enough. It's still comparable to my sealed BP1503 with about 1000w going to it.

I ended up porting it. It's a 3 ft^3 (net) box tuned to ~18hz with a 30" long 4" flared port. I used 4" sewer pipe elbows to make the "loop" at the top of the box. I think it might be tuned to low for the bash amp though. According to PE, it's 3db down at 18hz with the high pass. I might experiment a little with the volume to see if it makes a difference, but it will be a while before I get to it. I'll post some pics later tonight when I get home.

[jdb]

I finished the rough in and am giving it a test run now. It sounds pretty darn good but I don't think the 500w bash is enough. It's still comparable to my sealed BP1503 with about 1000w going to it.

That's great. I fed my sealed box 900 watts and it wanted more so now I have 1400 watts going to it. The increased power made a world of difference.

How is the 4" port working? Do you have any noticable port chuffing or resonance? I still haven't built a ported box for my other one.

[PoorboyMike]

How is the 4" port working? Do you have any noticable port chuffing or resonance? I still haven't built a ported box for my other one.

I haven't noticed any port chuffing. I've had subs that sounded like freight trains and this one seems fine. It's probably just a matter that I don't hear it, since everything else is so loud by the time it would become an issue.

Here is the rough in pics. It will eventually be down firing, with 2 1" oak dowels about 4" long on each corner, and a mdf base with the big PE spikes under it. The sides and top will be oak (veneer on sides and 3/4" ply on top) and I'll trim it around the top and base with 1X3 oak boards. I might even put a fake raised pannel door on the front so it looks even more stealthy.

Oh, and I wanted to try out the PE vinyl on the bottom but as you can see in the pics, I need to hit it with the iron again. Also, notice the filled driver hole on one of the sides. I was going to mount it there, but after the 1st cut, I realized I wouldn't be able to fit the port and the trim. Luckily I only went about 1/16" on the 1st pass. ops:

[WillyD]

Cool. I dig it!

[jdb]

Yeah, looking good. I like your ideas on finishing it. I hope you find that the 500 watt bash will work - it would be a shame to take it out now.

[PoorboyMike]

Yeah, looking good. I like your ideas on finishing it. I hope you find that the 500 watt bash will work - it would be a shame to take it out now.

Thanks guys.

I still want to try a db500 in it just to see if there is much of a difference. I think they will be pretty close with the bash amp. I can hear that TC12 asking me for alot more power and a small, sealed box.

How does the output compare to the PB10 now that you have more power?

[jdb]

How does the output compare to the PB10 now that you have more power?

Much better. I'm not EQ-ing it so it doesn't have the extension of the PB10. SQ is great. SPL is still less (by ear, not meter) than the PB10, but I have not level matched them so ... take this observation with a grain of salt. I also have some pretty serious bass trapping in that room.

I have the driver out right now to finish the enclosure. When I get it put back together I will take some measurements.

[JonMarsh]

This looks like an interesting way for me to do something with my BPD1203's. Gonna have to hunt up the T/S parameters and see... I like the subtle Octagonal shape, though I'll have to ponder the amplification options a bit.

[PoorboyMike]

My friends wife played the WAF card on this and said it was WAY too big. So now I'm stuck with a sub I don't need. I still don't have a finish on it and I'm not sure I like the dowel legs, so who knows what I'm going to do with it.

Anybody need a good sub? :B This thing sounds great and goes deep, but could use a bit more power. I would say it's quite comparable to an SVS Ultra with the 18hz tune.

[Dennis H]

Dang, that's a pretty looking sub, Mike! I hope you find a good home for it with someone who appreciates the craftsmanship.

[JonMarsh]

Great job you did on that Mike- it's hard for me to believe that with all the effort you put into this, and the nice "traditional" wood style for the cabinet, that she won't let you put this creation friend's living area- that's a real shame on many levels. Even though I'm quite a Danish Modern kind of guy myself, i'd be real tempted to clone your design. (I've got sub drivers stacked in a storage unit that I haven't used yet...)

Thumbs up to your workmanship and efforts! :T

~Jon

[---k---]

Mike,
I just showed my wife your photos. Her reaction was the same as mine, "Wow!" She said that your friends wife is nuts. Looking over at the my sub, I have to agree. I think tons of wives would prefer that to most subs - DIY or retail.

[PoorboyMike]

Thanks guys!

My wife actually likes it a lot. I think she likes it more than my sealed 1503 but doesn't want to hurt my feelings since it was my 1st build:



I don't get other wives some times though. My "friend" really wanted this after comparing it to his Bose "bass module". Said he couldn't believe what he's been missing all these years and felt like a little kid in a candy store for the week or so he had it (he borrowed my NatP's at the same time. He doesn't like Bose anymore :B ). He even had it in a position where it looked like a corner table. And you can put pictures or a plant on it to make it even more "stealthy".

Oh well, maybe I'll have to finish it off and replace the other end table in our living room. It's the only way it would fit though with all the other gear I have packed in there. :T