2 x 15" TC-3000 Sub

[DennisP]

Ok, I've been playing with various sizes and configurations, and actually the best one for my particular room is the last one I posted, and increasing the depth to 38" overall to appease SteveC. :P So that would give 6" of clearance from the port to the back of the driver, which is a little bit better. :B

I'll probably take the extra volume out of the width of the unit (the 4'-6" dimension), because it would be nice to reduce that by a couple of inches.

One thing is clear- this thing is a MONSTER. I think it will need it's own email address after I'm done. :E

I just want to be clear, just in case anyone is wondering- an IB was, in fact, ruled out by my wife many moons ago, hence this crazy route! :B But "wait till she gets a load of this". :twisted:

-Dennis

[SteveCallas]

Given any thought to two seperate enclosures? Or is one larger one a better fit for your room?

[steve nn]

Given any thought to two seperate enclosures? Or is one larger one a better fit for your room?

mmm

[Mark Seaton]

Hi Dennis,

While I may want to put on my asbestos suit before making such a suggestion, if you wanted to keep that depth shallower, even closer to 30-34" as you mentioned, I think you might have another option for the port location.

You mentioned the sub will be backed up to a wall. One of the reasons people say to keep the port exit clear of box walls is to keep the end termination or loading similar on both ends of the port. That noted, how about moving the port to the back bottom of the enclosure. Literally touching both the back and bottom walls of the enclosure. All of your bracing and other factors can remain the same. Aside from moving the port out from behind the pole vent of the left driver, the placement of the box against the wall and the box being so large, each end of the port effectively sees a very similar environment/end termination. The brace I suggested you have at the end of the port is akin to the box side for the other end of the port. I would expect you might end up with a slightly lower tuning with this configuration than in the middle, but I don't think it would be very significant.

Others here may have actually done direct comparison of such a configuration and can more specifically respond. I can only offer that I have used, tested, and built a few speakers with the ports configured this way without any audible issues, but I never had a comparable box with a different port location to compare to. I personally don't forsee any problems, and think it would work out well, and possibly allow a little smaller dimensions.

While we know SteveC will cheer on for a bigger and bigger box , as an architect, you well know how a few inches more or less to walk around or trip on may or may not come into play. With that large a port and enclosure, I doubt a slight reduction in box volume will be dissappointing in any way. After all, you are the one who has to live with it!

Just an idea.

[ThomasW]

I've been waiting so long to post this smiley.

While I may want to put on my asbestos suit before making such a suggestion,

Let get'm boys......:f>

[SteveCallas]

Given any thought to two seperate enclosures? Or is one larger one a better fit for your room?

mmm

Well I didn't mention the main drawback - he won't be able to use a 10" port anymore :B Just seems he's having a little trouble placing this box in his room.

While we know SteveC will cheer on for a bigger and bigger box

OORAH!

[steve nn]

;-x :k> :2guns: oke: :throwat: :toilet:
Take that Mark!..you better stick with sealed.

[noah katz]

"Well I didn't mention the main drawback - he won't be able to use a 10" port anymore "

With one driver he'd only need a 7" port/box.

[SteveCallas]

Correct, but I don't think 7" diameter sonotube is the easiest to locate.....and though it's a small difference, one 10" port is better than two 7" ports.

[---k---]

;-x :k> :2guns: oke: :throwat: :toilet:
Take that Mark!..you better stick with sealed.

Don't forget that Mark likes to play with those radiator thingies.

[steve nn]

Don't forget that Mark likes to play with those radiator thingies.

Noted! I'm certainly out of liege in messing around with Mark, I just got such a laugh out of Thomas's post.

Correct, but I don't think 7" diameter sonotube is the easiest to locate

It's a bugger of a size to find.. 6"- 8 - 10 is easy around here like the 20 and 24", 22" is very challenging.

[JonW]

Hey, this is a fun thread to read through- someone getting excited about building a monster sub. And I'd like to note that Dennis' realizations come after being egged on by some of the real bass addicts here. This place sure is starting to feel a lot like a crack house. :P


These two guys have a very good, if practical, point:

Also, 27.5" x 36" isn't small. Be sure to double check your doorways and any turns you need to make to be sure you can get that monster into your room! You could probably calculate out a rough estimate, but that's going to be one heavy box, even in Baltic Birch.

Given any thought to two seperate enclosures? Or is one larger one a better fit for your room?

Two smaller enclosures will be MUCH easier to work with versus one massive enclosure. During construction, during placement, and should you ever have to move to another house. Heck, even if you live a long, happy life in that house and pass away, smiling, in front of your subs. Consider your heirs and what they will be faced with. :P

If designed properly, do you guys think that 2 enclosures could sound as good as one big one? Total volume might be slightly larger, overall, but I think it would be physically easier to deal with. Then again, you've got cancellation issues to deal with 2 subs. Hmmm...

[DennisP]

Hmmm...I'll try monkeying with the enclosure with Mark's suggestions and post back again... It's really just the 36"+ depth that's bugging me, the width and height are a-ok.

-Dennis

[JonW]

the width and height are a-ok.

Also consider the weight.

I'm a newbie to this DIY thing. So I'm still getting a feel for it. But these projects tend to be much more cumbersome to deal with in real life than on paper. (wood weighs more than paper- go figure) I'm building my first real speaker now (Module MT). It's only a small bookshelf speaker. But I added a lot of bracing so the volume creeped up a bit. The cabinet, alone (no drivers), has got to already be pushing 30 pounds. It's more difficult to move around the work bench than I would have thought. A 200 pound sub might get a little tricky, especially if it's in a quite large box. Just something to think about. You can't really go wrong no matter what you try. Have fun. :T

[noah katz]

"do you guys think that 2 enclosures could sound as good as one big one?"

I'm surprised no one mentioned the benefits of multiple subs.

http://www.harmaninternational.com/wp/index.jsp?articleId=1003

http://www.avsforum.com/avs-vb/archive/index.php/t-484806.html

[steve nn]

Hey Dennis..What about switching over to the dual RL-p if you cant make it pencil out? 600 raw would come in at around 16.2 Hz tune with the 10" port. If memory serves me correct your at 660-70 raw now? That might reduce the size down to just what your looking for?

[DennisP]

A single monster works better than 2 subs within my room. I had briefly considered the idea of 2 co-located subs, but it's not really possible.

-Dennis

[DennisP]

Hey Steve,

I skimmed your last post and was out of town until today (Vegas!), I hadn't considered reducing the box size like that...I'll see what that gets me!

-Dennis

[DennisP]

Okay, it looks like I overestimated (by quite a bit) the mounting depth of the TC-2000. I took another look at the photos on the website and it looks like I was off by 3 or more inches. I have an email into TC to get the official dims for the 15" (only the 10 and 12" drivers have diagrams posted so far).

But for now, if it all shakes out, I think this is it...

-Dennis

[DennisP]

Well, July and most of August have flown by and I finally found myself a cabinet guy locally that can help me out (through a family friend). :T The design is still pretty much the same as it was, although now I'm trying to get the size down a little bit.

I know that about 330L per TC-2000 worked out great, but I'm now considering going with the SS equivalent (RPL-15) since I believe it needs a little bit less volume. The question is, how much volume is ideal for similar tuning, port size and length, etc.?

-Dennis

[SteveCallas]

260 effective liters per driver and 600-900 watts. Do you still want one large cabinet or would two discrete subs be better? I believe steve nn is selling finished RLp15 LLT sonosubs - that might be an option if you want to save some time and effort.

[DennisP]

Well, that puts me in the ballpark right away!! Score! That would mean 520L or about 600-610 after factoring in the bracing, port, etc. Is this still a 10"D 34"Long port we're talking about? (I remember Steve's was 10"D, but don't remember the L.

BTW, pne single enclosure works better, and the sub will sit horizontally on the ground (height limited to 29"- the bottom of my fixed FP screen. I'll upload some pics of the front of the room tomorrow evening so you guys can see the space I have to work with.

Thanks for the input Steve, I really appreciate it!

-Dennis

[SteveCallas]

Yes, steve shot for 600 liters raw to end up with the 520 effective - comes down to your bracing to determine what you need to shoot for raw. Port will be 10" diameter and 36" long. WinISD says that will be a 16.2hz tuning, but in steve's case, it appears the real world tuning came in at just below 15hz, which is a good thing. You could use 34", but I wouldn't go any shorter than that with the 10". You could also go with two 6" ports that are each 30" in length, but the single 10" reduces air velocity more. Use a 3/4" roundover on the outside. Feed it with 1200-2000 watts.

[DennisP]

Thanks Steve!

I was looking at either Behringer, Carvin, or the Crown Xti series for amps, I think those are listed in price order, from cheapest to most expensive. The Crown has some EQ built in, is that useful for the extra $130 over the Carvin?

-Dennis

[SteveCallas]

Which Carvin model were you considering? Unless fan noise is going to be an issue, I'd go with the Behringer, as it will give you a bit more power for your money at the expense of louder fan noise. If you want Carvin, I'd probably go with the DCM2500 - while 600 watts per driver would cut it, this design can handle a bit more power than that

[DennisP]

Hi Steve,

Yeah, I was looking at the DCM2500, and I also noticed the Crown Xti2000 for yet even more money (the crown is 800W per channel into 4 ohms and adds some basic EQ, crossover settings).

-Dennis

[Al Garay]

Check pricegrabber.com, the XTi2000 for $650 including shipping.

[steve nn]

Well, that puts me in the ballpark right away!! Score! That would mean 520L or about 600-610 after factoring in the bracing, port, etc.

Alright! now your cookin. 8)

while 600 watts per driver would cut it, this design can handle a bit more power than that

At 750 per, mine still has more to give.. just what it has to give is beyond me, but I wouldn't be afraid what so ever at throwing 8-900 per driver at it. It's nice to see your making some nice headway Dennis.

[DennisP]

Thanks Steve!

Here's a version with a slotted port to allow a little more clearance behind the drivers and to stiffen the cabinet quite a bit since it's all single layer. Comments welcome as usual. The port area is very close to a 10" diameter port (about 2% bigger), and I left the length at 36", but I'm not sure if that still applies with this port type. Also, is there any way of predicting port noise with something like this?

-Dennis

[WillyD]

At 750 per, mine still has more to give

Dang Steve...I can't imagine that your sub is capable of anymore, and I haven't even heard it. Do you really have any idea of its true max-output capability? I guess until you got more power through the drivers, you won't know...right?

[steve nn]

I'm sorry Dennis I cant open that up for some reason, maybe it's my security settings or something? I doubt I would be able to give you a definitive answer considering I generally speak from experience instead of modeling.

Dang Steve...I can't imagine that your sub is capable of anymore, and I haven't even heard it. Do you really have any idea of its true max-output capability? I guess until you got more power through the drivers, you won't know...right?

No I really don't Willy?..it's like you say, maybe another 400 watts split between the two drivers would do it?? Well..it's not needed anyway, but it would be nice to know.

[SteveCallas]

If you bumped the power up to 1000 watts each, you'd gain only ~1db more output. However, the amp would probably be better behaved at 1500 watts, and you'd have a bit less distortion - though when you're playing bass from movies at 119db peaks, I don't know how much of a concern some distortion is :B

[DennisP]

Hmm...here is a JPG version, see if this one works...

[SteveCallas]

I believe square ports will result in more turbulent air flow compared to cylindrical ports - any reason you don't want to go with 10" sonotube? Two 6" tubes would work too, just not as well as a single 10".

[DennisP]

I wanted to provide a bit more clearance from the back of the drivers, based on past suggestions. Strangely though, Kyle at TC Sounds recommends only 1" of clearance from the back of the driver for effective performance.

I also am worried about keeping the depth of the enclosure down to 30" max or 29" if possible, and when I place the 10" circular port, it is always 6" away from the back wall, which I'm told is too close.

-Dennis

[steve nn]

Ok I see. Dang your enclosure looks very close to another I can think of. Few "s taller, a " deeper and a 1/2" wider. I presume your talking about building the slot/port out of wood? I think I would be afraid to try it myself, not that it wouldn't work, but like Steve says you could be asking for degradation of your bass? That's allot of work to be chancing like that. I was concerned about being so close to the drivers also. If I had to do it over again I would just go ahead and bring the port a little closer to the back wall by a " or so and not worry about it. I have went much closer than that. I would go with 8" from the back myself and that would give you a " more clearance in front than what I wound up with...you'll be good. What do you think?

[steve nn]

it is always 6" away from the back wall, which I'm told is too close.

I see we posted at the same time. I don't see how your coming up with 6" considering your a inch deeper than what I built?? Do you have you drivers inset more than 3/4" on your baffle?

[DennisP]

Nope, they are inset 3/4". I will post the round port version tonight to show you what I mean and then you can tell me if I'm missing somethin'.

-Dennis

[SteveCallas]

You can do two 6" ports that are each 30-33" long - that should help in clearance issues. Port velocity goes up a bit, but I'd imagine it's still better than a square port......I dunno? Anybody here know more on how a square port relates to a cylindrical port?

Strangely though, Kyle at TC Sounds recommends only 1" of clearance from the back of the driver for effective performance

I don't doubt for one second that Kyle knows 5x as much about audio as I do, but I'm 99.9% certain 1" clearance from the drivers for a 10" port is asking for performance degredation :B

[steve nn]

I don't doubt for one second that Kyle knows 5x as much about audio as I do, but I'm 99.9% certain 1" clearance from the drivers for a 10" port is asking for performance degredation

OK I see what maybe the issue is. Steve are you speaking of the port wall or the bottom mouth of the port?..or maybe both :lol:

[Dennis H]

You can do two 6" ports that are each 30-33" long - that should help in clearance issues. Port velocity goes up a bit, but I'd imagine it's still better than a square port......I dunno? Anybody here know more on how a square port relates to a cylindrical port?

Yeah, in theory, a square port would have a bit more turbulence at the corners. That's why airplanes have fillets where the wings join the fuselage. However, I think the effects would be quite small compared to what happens at the ends of the port unless you're using something with a big flare, like an Aeroport. Personally, I wouldn't sweat it and would be very comfortable with a square or rectangular port. Slot ports and t-line enclosures have been used successfully for a very long time. If you needed a really short/shallow enclosure, you could do a folded port where you have staggered "backwalls" on the enclosure and the port was say 4"x20" and however many layers you needed to get the port length. The ports you guys are using are so oversize that chuffing isn't really an issue.

I don't doubt for one second that Kyle knows 5x as much about audio as I do, but I'm 99.9% certain 1" clearance from the drivers for a 10" port is asking for performance degredation :B

I haven't seen Kyle's comments in full but I suspect he's talking about how close the driver's pole vent can be to the back of the enclosure. I doubt he'd recommend blocking the port with the driver's motor if that's what's being discussed.

[steve nn]

I doubt he'd recommend blocking the port with the driver's motor if that's what's being discussed.

Fudging a couple inches on the wall with a 10" port doesn't seem to much of a compromise to me, but at a few inches at the mouth, I would be very concerned. Just think, we're talking about a box the size of a refridgorater and we're still looking for space. :lol:

[DennisP]

Ok guys, now I'm really confused re: cylindrical vs. rectangular ports. :lol:

Is my calc. for the rectangular port at least correct per this assumption:

Take port area of circle port, convert to identical area rectangle, keep length the same.

-Dennis

[ThomasW]

Round.... :T

[Exocer]

Has anyone noticed the TC-3000's Xmax decreased 4mm since it was first available? Hope Im not going crazy, but I definitely thought it had 34mm one-way linear excursion.