Klipsch SUB-12 Subwoofer (1 Viewer)

[Robert_J]

Brad nails can be left in. They are small enough to not impact sanding. Screws just hold the wood while the glue dries. Unless countersunk, they will get in the way of sanding. I have never seen an enclosure "explode" due to sub pressure and this is using subs like this - . That sub has 3 times the excursion of the JBL.
I've never heard of using that. Polyfil or fiberglass stuffed at 1 pound per cubic foot will slow down the rear wave converting the sound to heat. This tricks the sub into thinking that the enclosure is about 10% larger than what it really is.

 

[BraveHeart123]

Ok got it. I will use brad nails. How thick should be polyfill?? Do I need to glue it against the inner walls?? How about the holy magnet brace at the back??
Another important question.... what is the purpose of the holes in the horizontal magnet holy brace??
Do they cause sudden air compression and expulsion of air just like the piston moving inside a cylinder in an engine and the compressed air pushes it back up with immense force???

 

[Robert_J]

At 1 pound per cubic foot, there is no gluing needed. Just stuff it in.
Allow more air space. Nothing more.
Look at the link on page 3 to the TC-3000 design. One big hole in each brace. Or the other design that uses window pane braces (a big X with 4 openings called panes). You don't need all that material in the box so it is removed.

 

[BraveHeart123]

Um almost done with the box prep work. Put together all the pieces and waiting for the glue to dry. Later I will apply wood putty to completely seal it and make it air tight. Also installed the binding posts on the back wall of the box to connect with external amp.
One question. How to wire the sub (JBL GT4-12)?? Although, it's a single voice coil 4 ohm sub but it has four terminals and none is labeled +/- . How to connect the wire between sub and binding posts??

 

[Robert_J]

Post a pic of the terminals.
Use a 9v battery. If you quickly touch it to the sub terminals and the cone moves out, then the positive on the battery touched the positive terminal on the speaker.

 

[BraveHeart123]

here's the pic.... see the four terminals

I checked and terminals are marked on the underside of the terminal plate with +/-. But again, why four terminals on 4 ohm single voice coil sub??

 

[Robert_J]

So you can parallel another sub off the same terminals. Each pair is connected to the same tinsel lead. Doesn't matter which you choose. The side terminals or the other terminals.

 

[BraveHeart123]

The sub is almost done. I will be getting Crown XLs 602 in a couple of days.
How do I connect it with the system? Is it like this .... AVR > BFD > External Amp > Sub??

 

[Robert_J]

That is correct. My setup is Pioneer VSX-1014 > BFD > EP-2500 > TC-3000. I used RCA to 1/4" mono plug cable to connect the receiver to the BFD. I am currently only using 1 channel of the BFD also. If needed, I can stack the channels for 24 bands of EQ.

 

[BraveHeart123]

Is there anything wrong if I use XLR-RCA connectors instead of RCA to 1/4" mono??
I am also using one channel for sub eq. Is there any way I can utilise filters on the second channel for eqing one sub??

 

[Robert_J]

Nothing wrong with XLR. I had 1/4" cables already.
I'm pretty sure there is a way to "chain" the 2 channels together.

 

[BraveHeart123]

And what that might be? Also, the local store is out of stock on Crown xls 602. Crown 802 ($650) is available but it's out of my budget. The only option left with me is Yamaha P5000, so um gona go for it today. If I keep running any sub at 2 ohms out of equation, will P5000 be fine??
Update: Just finished up the sub enclosure. Thot I'd share the pix. I haven't focused on the cosmetics coz my main aim right now is the in-room response. Once I build up confidence, then I will pull off a bigger and better project. But for now have a look at my first DIY sub pix;

Lemme know if the polyfill stuffing is fine. I will fire up this baby as soon as the yammy arrives. Cant wait to plot the FR and see how it performs. Let's hope it exceeds my expectations!!!

 

[Robert_J]

Stuffing looks fine.

 

[BraveHeart123]

What about P5000? will it be fine?

 

[Robert_J]

The P5000 is more amp than the JBL can handle. You will be able to use it for almost any DIY sub. That is until you get up to the ultimate level like this guy. He uses a true, 5,000w amp per pair of subs. 20,000w of power to the eight 18's in that room.

 

[BraveHeart123]

Like I said, this is not the first and last sub i am going to build. I just wana know if P5000 will work fine with this sub. Plus I am going to get hold of Apline Type R 1242D in January next year and go for a ported design

 

[BraveHeart123]

I've shelved the idea of buying P5000 for now. There are hardly any reviews on this amp and this makes me skeptical about using it with sub. Will wait till january for behringer EP 2000 or 2500.

 

[Robert_J]

The current models are the EP-2000 and the EP-4000. Exact same amps as the EP-1500 and EP-2500 respectively. They only thing is the addition of a peak power rating. Testing results for sub use are identical.

 

[BraveHeart123]

Hi Robert..... u must have thought this thread was dead and all your assistance in DIY sub had gone down the drain. But I was low on funds coz I revamped my entire HT (Onkyo TX-NR809, Klipsch RF-82 II, RC-62 II, and RS-52 II) and waiting for the right time to get started.
My wife is travelling to US tonight and I have talked her into getting me Crown XLS-1000 pro amp to power my DIY sub primarily. She is deadly against my HT craze . Latter I can use it power my mains (Klipsch RF-82 II).
I need your opinion on this amp. I mainly selected it coz of low weight (Class D), 2 ohm stability, low price, and rave reviews.
Can you pls comment on whether my avr (Onkyo TX-NR809) can feed enough volts on its pre-outs for the Crown to work as desired?? Coz I've read a couple of people complaining about low input voltage from AVR causing the Crown to not perform to its optimum.

 

[Robert_J]

I haven't seen that complaint in a few years. I think all of the major receiver manufacturers can now drive a pro amp easily.
Crown is always a good choice for amps. I'm not familiar with that model but I definitely know the name.