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DIY subs - right direction?

1K views 34 replies 16 participants last post by  PTMD 
#1 ·
Okay so, learning more and more about DIY subwoofers and I want to share a few things to make sure that I am going in the right direction and what I am consider is

1. Keep it simple

2. Beat out major brands and be cheaper

3. Sealed box: first time DIYing a subwoofer, would like it to go well first

4. Subwoofer driver: two 15's (IXL 15.2.2, Dayton UM15-22, SDX15) - all seem like fair options
- dont think i can go 18's, as i probably dont have enough space under my screen (~25/30") and AMP choice may be an issue

5. Cabinet design: show me please

6. I know this forum is about seeking nirvana through Audio/Video - but I want my sub good enough (better than major brands), I am not focused on perfectly tuned at every hertz

7. see #1

Here is where I am concerned as I have already run 2 50ft RCA cables for my receiver (2 pre-outs for the sub) - sunk cost, I can pull them if needed

Option 1: AMPs that have RCA (LFE) connectors built-in. What AMP will deliver an amazing experiencing for the above mentioned subs? (keep in mind item #1 and #7)

vs

Option 2: AMPs like Nuke3000, which use Speakon connectors (hopefully correct) and will likely require a power converter (unbalanced to balanced) from the receiver, different cable, different binding post, etc.

I do not mind exploring option 2 for the AMP if it leads to a better overall experience and is simple

but option 1 seems even more simple

thanx in advance
 
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#2 ·
18" in 4cuft about 22"x22"x22" should work under your screen. You could build a pair and power them with the iNuke 3000dsp. If you located the amps in the same place as your subs, the RCA will work. They make a XLR>RCA adapter.

That's about as simple as it gets and you'll get great performance. There are several 18s to choose from depending on your budget.
 
#3 ·
Thanx - i did not consider that... I should mentioned that the main listening area is approx. 12ftx8ftx15ft = 1440 cubic ft. and ends at a bar table which is open to the back for another 8 ft

90% home theater

would not two 18 be too much? maybe two 12s, as oppose to two 15s

i was reading an article on SVS PB2000, that mentioned, one is good enough for rooms that are 3000 cubic feet

under U$250 for driver (but doesnt mean i have to spend all $250, especially if two 12s gets the job done.
 
#7 ·
Ok

so, two 18 (IXL-18.2.2) in a cabinet that is sealed measuring 22x22x22
- found a istonline.ca
- mdf from HD

powered with Nuke3000 (do i need/want the DSP version)
- still sourcing

using XLR/RCA adaptor from receiver to nuke
- probably found easily in Canada

from Nuke to Cabinet back use which parts? can any one share parts-express links - that would help
 
#9 · (Edited)
To make it easy you can just get already made speakon cables, these are cheap and from Canada. https://www.amazon.ca/gp/product/B006HRC8HI/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

The connectors aren't as good quality as the real Neutrik ones, but it is fine for home use. You just don't want to be plugging and unplugging these every day like people in pro audio do.

I would suggest building a "marty sub". They are actually EASIER to build than a sealed because you can use the handy panels from home depot and you barely need to even cut them because of the dimensions. With sealed it is really annoying. I have built dozens of boxes and I can build a ported twice as fast as a sealed.

18's will fit in a 24" x 24 " x 24" "marty cube" perfectly, check out the "marty sub faq" on this forum
 
#12 · (Edited)
I assume you suggest marty sub because its better (also it looks relatively easier to build). I will use speakon cables from the Nuke 3000 to the subwoofer. So that means on the back of my cabinet, i would fasten 1 speakon female connector.

this Chassis Mount Solder Type Speakon Connector (inside the box) is fasten to the 2 wires that go to the subwoofer

https://www.amazon.com/Neutrik-Chas...g_2?ie=UTF8&psc=1&refRID=41NE3EESPMKR15SEBWSP
 
#14 ·
You can get it for half that price at Parts Express:
https://www.parts-express.com/neutrik-nl4mp-st-speakon-connector-4-pole-panel-mount--092-053

Instead of 50ft of RCA, it is better to use 50ft of speakon cable:
https://www.parts-express.com/talent-sc1250-12-awg-2-conductor-speaker-cable-50-ft--101-315
That's because speaker cable runs at a much higher voltage, which is good for noise rejection and transmission at longer distances.

That way you can use a shorter RCA cable, one of these:
http://www.monoprice.com/product?p_id=4777

Alternatively you could get a 50ft XLR cable and a cleanbox pro and a short 3ft RCA cable, but that would be more expensive:
https://www.parts-express.com/art-cleanboxpro-stereo-balanced-unbalanced-converter--245-868

You'll want to get the DSP version because sealed subs need to be boosted 6-12db below 30hz.
You could fit a 18 in 19x19x15 if you had to, but the bigger the box the better the bass will be... go for the biggest box you can make.
With a single sheet of plywood you can make a 23x23x23 with a double-thick front baffle. Giving you 1.5inches in the front and .75" everywhere else.

Ported boxes are 12db louder near the tuning frequency, but their boxes are often much bigger. Ported boxes usually suck at making bass below 13hz at least without being the size of a fridge...
 
#16 · (Edited)
Get the DSP version... for a ported sub you'll need to set a HPF, for High Pass Filter, to cut out the really low stuff that could damage your sub. For a sealed sub, you'll want the ability to boost the low end. Having the DSP built-in to the amp is well worth the small extra cost. Trust, grasshopper....:)

Joseph
 
#20 ·
Two ported in your room size is going to be better than sealed unless you get more than two 18" good long throw drivers. Someone on here said that they don't consider 12" home theater speakers to be subs. I would agree as the space we are trying to fill is so large. You generally need double the subs and amps to make up for every 3" smaller sub. Though 4 12" subs spaced around a room is likely better than one 18" sub. Smoothing is another side effect of the drug.

Get a dsp amp (the inukes have a great dsp and are o.k. For power Until the big / over 26mm drivers..)

Bass should be classified by the Feds as a class 1 controlled substance, cause it is very addictive... My wife and kids are pretty much immune to only two sealed ftw21s and arseshakers in every seat. That is why I am building two more subs... The wif fell asleep last night durning the new whippy Ghostbusters and I think it was the bass and arse-shaking that put her to sleep... as it was before beddy by time. She was bassified!

I am building a 18" ported sub now for my father. Low ported subs put out a good amount of drug through most of what matters. You will miss the fundamental of helicopters, but going for that is like main veining... you might get there if unlucky ;)
 
#21 ·
thank you ... keep it coming

summarizing, just so I understand and order all the stuff properly in one shot

1. SUBWOOFER: TWO 18's - either Dayton, IXL, or SDX

is there a preference?

2. AMP: Nuke3000DSP, place in my A/V rack which is 15 ft away

3. CABLE (A/V receiver to AMP): use the following, likely get a shorter version, 3ft
http://www.monoprice.com/product?p_...utm_medium=11051853&utm_term=VigLink2-2917105

4. AMP to SUB: Going to remove my 50ft RCA cables and run 12 AWG speaker cables with a speakon connector on one end only (AMP side) (I assume its the same thing as putting on normal speaker connectors). The other end will remain bare and the bare wires will connect to the binding post - or should the other end have speaker connectors?

is this the correct way?

Speakon connector
https://www.parts-express.com/neutrik-nl2fx-speakon-connector-2-pole-cable-mount--092-198

Back of the subwoofer cabinet
https://www.parts-express.com/round-speaker-terminal-cup-2-15-16-gold-banana-binding-post--260-283

5. INSIDE BOX: 12 AWG speaker wire from binding posts to speaker (both ends are bare and bare wire ends are fastened to speaker and post)

6. CABINET: MDF or Baltic Birch

more about looks here, right?

7. SIZE AND LOOK: I like the marty sub look - seems relatively easy to build (considering that I build outdoor furniture part-time). The pictures that I have seen for the marty subs, either are square, taller or deeper (I understand that more cubic ft space is better), has anyone did a wide marty sub with the rectangle port on the side? is it the same thing, just turned on its side

i like the idea of 24x24x24 in terms of footprint - but if i could increase the volume by increasing the width - I would prefer that

thanx

ptmd
 
#28 ·
If you change the 40" dimension to 30", you need to increase the other dimensions to maintain a similar cubic volume. I am not familiar with modeling these in winisd, but you would want to model the changes before starting to cut. I am sure someone can weigh in here who is more familiar with ported box modeling. Sealed boxes are more forgiving of changes.
 
#33 ·
morning all - i was just thinking out loud about the passive radiator... :)

how is cubic volume calculated for a subbox?

i thought it was HxWxD, so a minimarty (24"x25.5"x40")/1728 = 14.17 cubic ft volume? or 12 cuft (taking off 1.5" from each dimension) - How did the FAQ get to 9cuft? what am i missing?
 
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