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Any reason NOT to do a THT?

post #1 of 211
Thread Starter 
Hey everybody,

I am finally going to be able to move my equipment in its own dedicated room! smile.gif It has all been just part of my entertainment system in my family room that is open to the entire house, but I just sealed off a room in the front of my house and need some advice from the experts! The room is about 17X20X9 with no openings to the rest of the house. My current set up is a Samsung 58" plasma (a 650 model I think), Denon 1713, Panasonic Blu Ray, Onix Rockets 550 mkII for mains, and a RSC200 Bigfoot center, and just no-name in ceiling surrounds. I also have a SVS PB2+, I think they changed the name to PB12/Plus 2 or something, but it's the one with 2 12's and the 900 watt RMS amp I believe. I am really happy with the sound of the system, but am very excited about what it will sound like in the new sealed room. I would however, like to build a sub, mostly because I LOVE the idea of getting such great bang for your buck so to speak, and because my brother that lives just a few minutes away has a huge wood shop with table saws, etc, and we have plenty of experience between us (and plenty of beer) to complete a build. I am very interested in doing a THT sub, and am not worried about the big size, since it will be in a dedicated room. However, lately I have been looking at some sealed builds using a stereo integrity 18 or 2 15's, etc. From what I understand, and please correct me if I am wrong, is that the THT design is very efficient (more than a sealed design) and will give me great bang for the buck (which is what I am most concerned about). When I hear people's reactions to the THT, I wonder why anyone would build anything else. The only "cons" that I would be expecting to take into consideration would be the size of the THT, and maybe not quite the same extreme low end excursion of a sealed design. So,

1. Any reasons I shouldn't follow my original plan and build the standard size THT to pair with the PB2+?

2. Am I missing any huge advantages by not going with a sealed or standard ported design?

3. Will the THT and the PB2+ be sufficient for the room size (approx. 3000 ft^3)?

Thanks so much for the help everyone. Nice to have you guys to spitball this with.
post #2 of 211
you've basically got it right. horns give more sensitivity, so you get more spl per watt and that is good for a number of reasons. downside is that they are large and like ported are bandwidth limited. ported are the next step down. smaller than horns usually, but can be more easily tuned to something like 15hz if you want that. sealed tends to be the smallest and least efficient, so you need more drivers/enclosures/and amps, which makes them the most expensive, but if your room can support the lowend, they offer the greatest extension. in-wall infinite baffle is kind of like sealed but uses your entire room as a speaker box, so they go all the way deep too, require very little power because there is no 'box' in the traditional sense, but they also require lots of drivers.

you may wish to have a look at lilmike's f20. it is very similar to a tht, but extends a little deeper and is probably a marginally easier build.

what the world needs is something like the f20, but designed for the si woofer. that would be some kick butty. I've napkin sketched something like that up, but haven't fully fleshed it out.
post #3 of 211
THT is a great sub, I built one a couple years ago (36") and loved it, but I moved and left it with my roommates as a parting gift.

A few months ago I built an f20, which I am currently using, and I love it as well. I had a Dayton DVC sitting around which is a perfect match. I'm currently watching "Oblivion" and she's having no problem belting out an uncomfortable amount of bass.

However, the f20 and THT are so close (to my ears) I'm lusting for a bit more.

Lilmike has his "lilwrecker" which is a large (29ft cu) horn, capable of 15hz of extension with a $120 driver (pioneer sws15). This brings me to my next point...
Quote:
Originally Posted by LTD02 
what the world needs is something like the f20, but designed for the si woofer. that would be some kick butty. I've napkin sketched something like that up, but haven't fully fleshed it out.

I feel the lil wrecker or micro wrecker fits this nitch perfectly. Unless you mean the 18" si....

I also like this beast a lot if you want a simple build with lots of output down to 20....

http://www.avsforum.com/t/1483849/8-tall-stereo-integrity-ht15d2-tapped-horn-sub
post #4 of 211
Don't overlook the Table Tuba. It is smaller and easier to build. It will reach almost as low as a regular THT if you can corner load it, and it will have more than enough output above 30 Hz unless you have a huge room. If you're going multisub, two TTs really start making more sense.

EDIT: Be careful about combining any horn subs with ported or sealed subs like the PB2+. Fitzmaurice doesn't think they will play together very well. Do a search for 'sealed' in this THT forum. If you go with a THT or TT, you shouldn't need more output than that unless you need high volumes below 20Hz.
Edited by darrellh44 - 8/6/13 at 11:08pm
post #5 of 211
Thread Starter 
Great ideas everyone! And great point, Darrell...I didn't think about the SVS playing nice with the THT, although I would like to keep the SVS if at all possible. I have been very happy with it and just don't think I could get enough on the used market to make it worth selling it. I will so some searching on that point but would appreciate other opinions on that pairing as well...very interesting. If I am planning on keeping the SVS, then maybe a ported or sealed sub would be more appropriate...
post #6 of 211
"I feel the lil wrecker or micro wrecker fits this nitch perfectly. Unless you mean the 18" si...."

yeah, that one...in something big...like a 35-40 cubic footer...with a low corner around 18hz.

something like this, roughly:





that would be 18" driver...18 foot long horn (roughly)...tuned to 18hz (roughly)...the 181818 :-)

i wonder if erich will have kits...lol
Edited by LTD02 - 8/6/13 at 11:36pm
post #7 of 211
What are you waiting for? Get to work....
post #8 of 211
Thread Starter 
That looks amazing, LTD02! Although I may have misspoke a little smile.gif I'm not sure if I want to have anything much bigger than the THT... But I definitely want bang for the buck, so I'm trying to research whether or not it would sound Ok with my current sub. Maybe a precut build from Erich would be more appropriate, although I have already purchased the plans for a THT and was kind of revved up about that. Hmmm... More research...
post #9 of 211
Quote:
Originally Posted by jkkwaz View Post

I'm trying to research whether or not it would sound Ok with my current sub.
Unless your current sub is horn loaded it would never keep up with the THT.
post #10 of 211
Thread Starter 
Thanks for the response, Bill! And I've already purchased the plans for the THT and am excited to get started. I had a thought though, and please let me know if I am entirely off base, but could I use the SVS that I have and set up the ports for low end excursion instead of higher spl and have that pick up some of the lower frequency duty and have the THT give me the punch I am looking for at slightly higher frequencies?

Edit: don't know if I explained that we'll enough... The pb2+ has foam plugs for the ports and adjustable crossover for different emphasis, either higher overall spl or lower frequency... I'm sure you guys already know that...
post #11 of 211
Quote:
Originally Posted by jkkwaz View Post

Thanks for the response, Bill! And I've already purchased the plans for the THT and am excited to get started. I had a thought though, and please let me know if I am entirely off base, but could I use the SVS that I have and set up the ports for low end excursion instead of higher spl and have that pick up some of the lower frequency duty and have the THT give me the punch I am looking for at slightly higher frequencies?

Edit: don't know if I explained that we'll enough... The pb2+ has foam plugs for the ports and adjustable crossover for different emphasis, either higher overall spl or lower frequency... I'm sure you guys already know that...

if anything, you would have the svs trying to add to the higher frequnceis like a nearfield mid bass module. its the lower end that it will not keep up with. thats assuming you EQ the THT (which you should). the output at the higher frequncies would be lowered to smooth the response out.
post #12 of 211
i built two low profile THT's. they are great subs. just effortless output. unfortunatley, my basement setup would not fit them and i had to sell them frown.gif
post #13 of 211
Another great reason to go the THT route is the plans and support. BFM's plans are detailed and if you ever get stuck, their is a nice community over at BFM's site all willing to help.
post #14 of 211
Thread Starter 
Great point, mynym, thanks!
post #15 of 211
Quote:
Originally Posted by brian6751 View Post

i built two low profile THT's. they are great subs. just effortless output. unfortunatley, my basement setup would not fit them and i had to sell them frown.gif
Did you look at Table Tubas to see if they would fit? Short of anything that would drive you out of the room, there's not that much difference between two THTs and two TTs in a closed room provided they aren't out in the middle of the room. Bill has low-profile TTs now.
post #16 of 211
Quote:
Originally Posted by darrellh44 View Post

Did you look at Table Tubas to see if they would fit? Short of anything that would drive you out of the room, there's not that much difference between two THTs and two TTs in a closed room provided they aren't out in the middle of the room. Bill has low-profile TTs now.

i didnt. doesnt go low enough for my tastes
post #17 of 211
Thread Starter 
Hey guys, thanks for all the awesome responses. One more question I am hoping you can help with. I am little confused about EQing my subs. I will be using my SVS and the THT to try to smooth my frequency response as much as possible. I will be using my Denon 1713, which has the audyssey multi eq XT, so am wondering if I will be able to tweak things enough with that or if I will need to get a BFD. I have a LOT more research to do as far as getting everything EQed, but for now am trying to get an idea of what equipment I'll need for budgeting reasons. I do have an spl meter as well, but am wondering what else I will need to do a proper job.
post #18 of 211
You can try the SVS and THT thing, but I can guarantee that you will either be holding the THT back, or the SVS will be silently farting alongside the THT's wall shaking output..

Unless you place the SVS right by your couch/LP, and the THT corner loaded near the screen.
Edited by diaz - 8/12/13 at 6:36pm
post #19 of 211
Thread Starter 
Thanks Diaz,

I will definitely play with positioning, and maybe not even use the SVS at all if that is the case. However, my original question still stands. Will the MultiEQ XT be sufficient to EQ the THT, or will I need a BFD or something? I know I have my research to do as far as EQing the sub, but I just need to know for budget reasons whether that is something that I will need. Anyone?

Thanks again guys...much appreciated. And I am getting super excited for this build...I have been so impressed with my SVS it's hard to believe the THT will be even louder!!
post #20 of 211
the distance to the subwoofer will be very different for the two subs.

the horn path inside the tht must be added to the distance when figuring the total.

it is about 18 feet long iirc.

so if the two subs are sitting next to each other, the tht will be 18 feet further back than the svs.

if getting the upper bass energy to land on your listening position in time and phase is important
to you, than different distance settings or dramatically different physical locations are required.
post #21 of 211
Thread Starter 
Thanks LTD02,

I didn't even think of that, great point. So are you saying that the distance setting in Audyssey is all that I need to do the EQ, distance, etc? No BFD or other equipment?
post #22 of 211
the distance settings would need to be quite different for each sub if you want them time aligned (which some argue for and some argue against).
post #23 of 211
Thread Starter 
Thanks, ltd02, and maybe I am just being dense here...so I apologize smile.gif. But I am still not sure whether my AVR will be sufficient for EQing. Would it do me any good to have a BFD? Would it make things easier? A friend has one for sale and I need to tell him if I want it. If my denon can handle it fine but I am curious if it will be a useful tool for me.
post #24 of 211
Thread Starter 
And I am not talking JUST for distance settings...for everything like EQ
post #25 of 211
if you get a friend price, why not grab it. that way you can eq the two subs differently as well.
post #26 of 211
Thread Starter 
Cool, thanks! Now I will become an EQ expert smile.gif I think I'll try the THT by itself first, and then decide if I would get any added benefit with the SVS.
post #27 of 211
Thread Starter 
Ok guys, last question, I promise! I have ordered everything for the THT build but the Bash 300w amp I was planning on using is sold out at PE. I have read that the Dayton SPA250 is a worthy replacement but I just want to make SURE that I won't be losing out on any performance...if it's even 1% I don't mind waiting for the bash. If I am going to do something other than the bash, how does the spa250 compare to the yung 300w? Worth the extra money? I have read mixed reviews on the yung...
post #28 of 211
Get the bash.. the spa has a filter centered at 20hz, you lose anything around that range. If you get the bash, it begins around 17hz (stock) which gives you the THT's full range. It can be set as low and 12 or 15 hz IIRC
post #29 of 211
Thread Starter 
Awesome... I'm glad I asked... They have it on Amazon... It's a bit more expensive, or they have a used one on ebay through PE for pretty cheap. Or I'll just wait for PE to get them in stock.
post #30 of 211
They do the job, if you can get one used that's in good condition, then that's fine too.. I personally just prefer to get something new, or if its used, then I want it from a reputable source.
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