Dual TC2000 15" LLT close to complete

[ahennings]

I've been following many of the threads about DIY sub and thought what the heck: I designed and built a 800L raw 94" x 29" x 21" sub with 2 15" TC2000 SVC speakers tuned to ~15Hz with a 10" port 27.5" long. I would like to thank all on this the forum for the knowlegde to build this beast. I will be using a SMS-1 and a Behringer EP2500 to control and power this thing.

I previously used a Kef PSW4000 and have a few pictures (from the SMS-1) of the tuned response from that, I did a quick set up of the LLT sub (still not in place yet) and tested the the response of this (forgot to take pics will this weekend) all I can say is wow. Within minutes I had the new sub flat to 15Hz (this is as far as the scale goes) this was a far cry from the Kef that I had to boost to get 25Hz. I will have to attach this to my walls more securely now.

I'll post some more impression this weekend when I get a chance to place then play with my new toy. FYI I built this near the location that it will finally rest because it weighs around 350lbs. Here are a few pictures:







Yes that is the KEF sub (quite a size difference) under my center speaker not the best placement but with wall treatments and the SMS-1 I obtained good results.

Thanks to everyone again and if you are on the fence about building a DIY sub just ask a few question do some planning then build it.

Adam

[DennisP]

Whoa! Size does matter!

-Dennis

[WillyD]

Hell yes! That is niiiiice. I am happy to see someone use the TC-2000s in a setup like this, since until now, they had all ben Rl-p 15s (not that they differ much...).

Within minutes I had the new sub flat to 15Hz (this is as far as the scale goes)

Haha, you need to get a decent measuring setup or have someone come over and measure it for you. I'd really like to see at least a 10-80Hz graph of it. What a beast...and she is pretty too!

[SteveCallas]

I've been following many of the threads about DIY sub and thought what the heck: I designed and built a 800L raw 94" x 29" x 21" sub with 2 15" TC2000 SVC speakers tuned to ~15Hz with a 10" port 27.5" long

I like this guy That's one awful big "what the heck", nice work :T

I will have to attach this to my walls more securely now.

I would try to avoid physcially coupling it to a wall.

Only thing I'm thinking is that with 800 RAW liters, a 27" long 10" port will not tune you to ~15hz. Your probably coming in ~650 effective liters, so I'd shoot for 35-36" of port length (~14.6hz). Is it already sealed up, and if not, can you take out the port, or no? If not, no big deal, you're probably tuned around 16.5hz, but you can get even more low end extension and protect the driver better while only giving up around ~1db headroom with a longer port.

Again, nice work :T

[steve nn]

That looks absolutely STELLAR Adam. Great job on the finish work! I have no doubt that it will measure out as well as it looks. Did I mention how nice the finish job looks? 8)

[derekbannatyne]

Yeah that looks awesome! What did you use for the finish?

[chasw98]

Welcome to the brotherhood! Nice, awesome monster you got going there. I guess resale value is kind of nil considering shipping :rofl:

Just curious, why go with a SMS-1 instead of a DEQ2496 or a BFD?

[nick77]

Great Job! Awesome finish work. Bet it rocks the HT room. :B

[---k---]

Wow,
I wish I had those skills.

[steve nn]

Wow, I wish I had those skills.

You can do this Ryan. :T

[ahennings]

Hello everyone, thanks for the comments now for a few answers (then back to the grind)

SteveCallas:
That's 800L interior box volume before bracing. With drivers, bracing and port I came up with about 720L (using Bassbox). I also used Unibox and WinISD all three came up with the port in the ~27.5" area, (the totla length of my port with flares is ~29") this also kept the 1st port harmonic above 200Hz (the longer the port the lower the harmonic) and the group delay at about 15ms at 20Hz. The tuning is at ~15.25 Hz (plenty low) plus with the close proximity of the walls to the port (I have read) will cause the tuning to be lower. With a port this size port laws bend a little for chuffing but just in case I also used a donut flare (https://web.archive.org/web/20061208...lliso/ring.htm) for the interior end of the port to decrease port turbulence.


Chasw98:
I went with a SMS-1 for the sake of simplicity. Within minutes I can change and adjust bass levels, set limits, change phase, increase or decrease rolloff (you get the idea) all with a nice little graph to look at. I'll post a pic this week end with the sub tuned.

derekbannatyne:
The wood is cabinet grade cherry veneer (to match my Reference KEF speakers) doubled with MDF and plywood on the front with more bracing than I thought was necessary. The finish is Minwax Polyshade Natural Cherry Satin (3 or 4 coats should get this finish to be close to my other speakers).

Adam

[dyazdani]

That's a great looking sub. It's a big one, are you going to leave it there in the room?

[WillyD]

I can't wait for further listening impressions!

I bet the cannon blasts in M&C are ridiculous with that monster.

Edit: Some music impressions would be great as well, since all too often, they are not mentioned.

[Exocer]

After seeing those pics I visualized having something like that in my 1000ft^3 listening space then reality struck. :T

I too would like some subjective music listening feedback. Great job!

How long did this project take to complete from start to finish?

[SteveCallas]

You can verify the tune by taking a close mic frequency sweep of just one of the drivers.

[Amphiprion]

If you're anywhere in Texas, I'd love to come hear/measure it

[ahennings]

A few more answers:

dyazdani:

No the sub will not stay in the location it is sitting in at the moment, it will move under my screen and support my center channel. I have some Vibrapod Isolation Feet for my center channel. If this doesn't work I will make a shelf that attaches to the wall to hold my center channel.

WillyD and Exocer:

I will definitely give some music impressions as soon as the sub is in place. If my memory serves I can give impressions verus the KEF sub and my old system of Sunfire subs (3) and Martin Logan speakers.

Time to complete (to this stage, one more night of finish work):

If I didn't have to wait for the the driver it would have taken a couple weekends. A could cut and fabricate all the parts in one weekend then assemble them and start staining the following weekend (~20 to 25 hours) plus modeling time.

SteveCallas:

I'll see what I can do for the messurements you want but I am limited to using the SMS-1 (which I must update the firmware to drop the LF to lower than 15Hz).

Amphiprion:

No luck Mark this beast is located in Minnesota and is just a little to large to move anywhere near Texas.

I will try to finish staining tonight and move into place tomorrow or friday (time permitting) then this weekend I will throw some material at it and run some tests.

Adam

[SteveCallas]

The SMS will work, but you may very well need the <15hz extension. Instead of putting the mic at your seat, put it right in front of the driver furthest away from the port. There should be a very noticable dip in output at the tuning frequency.

[ssabripo]

Nice Job!! DIY is the best, aint it?

now go get some measurements and share it with the brothas!!

[Scott Simonian]

Mmmmm. Yummy.



Nice work, Adam!

[ahennings]

Here is a quick SMS-1 calibration of the sub in place versus the old KEF sub. I haven't had time to listen to any music or watch any movies yet (I'm going out of town for a couple days) but this weekend should be interesting.

KEF Sub:



LLT Sub:



I'm not sure if I even had to label the above graphs 8O


If you notice the 15Hz setting is down 5 db just to try keeping the graph straight.

SteveC I tried putting the mic up to the driver farthest away from the port and obtained a reading at ~16.5 Hz (where the dip occurred). I may mess around with the port but I'm not sure it would be worth the trouble. I still have to decrease the low end with the SMS-1 just to level off the sub (most likely due to room gain).

The above tuning took me about 5 min but just moving the beast into place took me over an hour (time to move and set up my center channel and clean up a little).

Adam

[Remotia]

Very very nice, I'd love to hear that sub

[SteveCallas]

I'm not sure if I even had to lable the above graphs 8O

Such is the power of the LLT :T I get a chuckle when guys talk about how deep their subs can go, yet their in room response starts rolling off at 20hz.

If you notice the 15Hz setting is down 5 db just to try keeping the graph straight.

SteveC I tried putting the mic up to the driver farthest away from the port and obtained a reading at ~16.5 Hz (where the dip occured). I may mess around with the port but I'm not sure it would be worth the trouble. I still have to decrease the low end with the SMS-1 just to level off the sub (most likely due to room gain).

16.5hz tuning is just as I suspected. Definitely update the firmware to go below 15hz (it's free, correct?), and I would highly suggest you tune lower. I doubt you'll be taxing this sub in terms of output even at the most extreme levels, so trade a couple db of headroom for even more extension. The lower tune will naturally help level out the extreme low end because the 16.5hz tune in that size enclosure is showing a resurgence in output even before room gain - the lower tune will stay flatter in room so you won't have to use EQ (which means you won't have to use the built in high pass either), though a gently rising response in the deep end is a good thing in my opinion, as our sensitivity is reduced greatly the lower you go. You will probably notice a slight increase in sound quality with the lower tune as well.

Again, I'd shoot for 35-36" of tube length and keep the flares.

[peterS]

did you use a router or do you have access to a cnc machine?

also could you share how you did the finish

money removed, i think DIY subwoofers are the most satisfying performance wise as the most compromises are made in comercial models and t6he diy drivers out there are just much better!

[ThomasW]

did you use a router or do you have access to a cnc machine?

Hey! real men use a Jasper Jig and a jigsaw...... :T

[ahennings]

I'm back after a few days away but here is the progress so far:

SteveCallas: I took your suggestion and lengthened the port to 35.5" from end to end (keeping the flares). This was not an easy thing to do (took about 1.5 hours) but I think in the long run it was worth the effort. I really can't tell if the sub goes lower (it was already freaking low) but I noticed the the driver excursion was less and the amount of air moving thru the port was quite a bit less. This I believe will cause a couple of good things: makes the sub more sensitive (due to the fact I'm not using the full excursion of the driver) and also lowers the group delay a few ms (tightening the sub). Thanks for the suggestion this does improve the sub quite a bit. By the way the 1st port harmonic (which I was worried about is still non existent.

peterS: No cnc machine just what ThomasW said "jasper jig and a jigsaw". The finish as I stated above is just 3 coats of Minwax Polyshade Natural Cherry Satin (bought at Home Depot). In the following photo the sub looks darker than in "real life" and matches my other speakers well enough (not perfect but over time it should darken a little which will get them a little closer in look).

I have watched a few movies and all I can say is WOW. I have a very large room (40' X 15' X 9') and my other sub just could not do any justice to movies. I also use 3 buttkickers to augment the "feeling" of bass but now I have them reduced even more into the background (Crossed over at 40Hz and the volume on the amp at 1/3) which is a good thing. I use an Athem AVM20 Preamp that have a bass limit volume I used to have this set at -28db (before distortion bogged down my KEF sub) now I have this set to -10db (and I believe I could easily go higher but I figure I will break the sub in a liitle before destroying my walls from the sonic impact of the sub.) With the Anthem I can set up a different setting for bass control on Cinema vs Music. I have not had time to do this but I have listened to a couple cd with the cinema setting and again all I can say is "why didn't I build this thing sooner." The control and depth of the drums and bass guitar are much more solid than my other sub (it seems effortless for this beast). Hopfully in the next week or so I can take some time to create a music setting and experiment some more (its just difficult when all I want to do is throw in another movie sit back and enjoy).


Here is the sub in place:



Here is a quick setup using the SMS-1 to control the sub (if you notice it still only reads down to 15Hz but I have upgraded the firmware to allow frequencies down to 5Hz thru to the sub) this took about 5 minutes and I will be tweaking to hopefully improve the response shortly.



Again I'd like to say thanks to everyone on this forum and if you are on the fence about doing something like this take the plunge, its an enjoyable and interesting project to undertake.

Adam

[soho54]

Really nice setup. :T

I love the view in the pic. The screen and sub look awsome.

[WillyD]

Holy Jesus, this sub still makes me smile. What a beast. ;x(

Edit: If you ever get a chance to play the DTS track of WOTW, please tell us if you experience any bottoming-out.

:rofl:

[soho54]

NO! Not here too. :??

[WillyD]

NO! Not here too. :??

I just had to do it... :lol:

[---k---]

Looks impressive.

It would be nice if you resized your SMS pic to avoid having to scroll side to side.

[JoshK]

Really excellent veneering work! Looks splendid.

My wife, though, asks if you have vampires in there? :lol:

[SteveCallas]

Excellent work ahennings, glad you went with the longer port :T I don't doubt the finish matches the speakers perfectly, cameras have a funny way of changing perception.

SteveC: I took your suggestion and lengthened the port to 35.5" from end to end (keeping the flares). This was not an easy thing to do (took about 1.5 hours) but I think in the long run it was worth the effort. I really can't tell if the sub goes lower (it was already freaking low) but I noticed the the driver excursion was less and the amount of air moving thru the port was quite a bit less. This I believe will cause a couple of good things: makes the sub more sensitive (due to the fact I'm not using the full excursion of the driver) and also lowers the group delay a few ms (tightening the sub). Thanks for the suggestion this does improve the sub quite a bit. By the way the 1st port harmonic (which I was worried about is still non existent.

It should also make the in room response easier to tame, yes/no? As for the first port harmonic, yeah, that shouldn't be a problem with a typical 80hz crossover. Hear that Ryan? People will say anything when they make their livelihood selling a product they want to compete with DIY, no matter how much of a reach it is.

Edit: If you ever get a chance to play the DTS track of WOTW, please tell us if you experience any bottoming-out

Leave the fools and sack riders to believe what they want to, actual LLT owners know better. ahennings now has reference level capability down to the low teens and great sound quality for what I imagine can't be more than $1200 - correct me if I am wrong.

[Remotia]

Very nice response curve. I bet that system thumps! I think I'm going to open up the TC DIY forum and allow users to post their own systems and pictures so others can follow.

I hope you guys can post your systems there. We love to see the pictures over here, makes it worth our while.

[WillyD]

Leave the fools and sack riders to believe what they want to, actual LLT owners know better. ahennings now has reference level capability down to the low teens and great sound quality for what I imagine can't be more than $1200 - correct me if I am wrong.

It was more of a joke than anything, Steve. :T

And yeah, I know it is a ridiculous sub. I wish I could hear it.

[---k---]

Steve,
We should back a bit, and I should clarify that he didn't say that bad things will always happen when you build them that big. It was more of, sometime bad things happen and a combination of things can cause port resonance or other bad things. That was followed by, you need to build it and see what happens. It was never, don't do it, because it is bad. It was, build it, see what happens, and rebuild slightly differnt if bad things happen.

BTW, soory for the OT, but I beleive my father-in-law will be intown next weekend with his pickup. We might make that trip to Menards for some of their BB.

[Brian Walter]

Leave the fools and sack riders to believe what they want to, actual LLT owners know better. ahennings now has reference level capability down to the low teens and great sound quality for what I imagine can't be more than $1200 - correct me if I am wrong.

Steve, I may a little naive here, but what are you referring to in regards to LLT?

Brian Walter

[ThomasW]

Steve, I may a little naive here, but what are you referring to in regards to LLT?
Brian Walter

http://www.avsforum.com/avs-vb/showthread.php?t=719694

[indygreg]

i am building my version of this today. mine is actually 775 L after the braces and the port.

i am concerned that my port calculation is wrong. i have a 23.95cm diameter port (it is not round but that is the effective diameter) and tuned to 15hz in unibox it says the port should be 46.72cm long. that seems much shorter than the one in this thread.

greg