Nooby-noob thread. Appreciate pointers.

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Hi there from Scotland,

Another where to begin thread. I like Dub Step music (very bass orientated) and I want it so sound and feel great. I don't need to shake the house down though, maybe just nudge it a little, so I want to build a subwoofer. My stereo speakers are fairly good quality Missions, but only work down to 40Hz.

I'm a physics teacher so I have access to most of the equipment I might need and my friend who teaches wood work will help me build the enclosure so that doesn't bother me. He's skilled.

I'd like to keep it below $200, preferably around $150. I know I'm not going to get top audiophile quality at this price, but I'm mainly doing it for the challange/fun and to learn. I can always try a more expensive project later.

I'm short on cash, but long on space. My living room is huge.

1)How do I learn the basics? I'm really struggling with actually understanding the jargon even after I look up what it means. Book?

2)Can anyone share a project with me that I can copy OR just tell me 'this' driver, 'this' enclosure? that would narrow my studies.

3) Will my Dub Step have frequencies that go all the way down low or is there an enclosure design 'trick' I can play with harmonics?

4) If I only have one Sub, do I just put the left and right channels from the stereo both into its input?

5) I was recommended to build an amp based around an LM3886. I'd probably just buy a kit (see linnk below). What size of driver can I power with this?

http://www.ebay.co.uk/itm/1-LM3886T...usicalInstr_Amplifiers_RL&hash=item336c3ddc7d

don't feel like you need to answer all these questions, any help is appreciated.

Thanks,
Ewan
 
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Cheap sub drivers

I'm short on cash, but long on space.
.
That said, you may want to look at the car audio scene for a driver.
Some very cheap for their performance drivers available in that scene.
.
One example Infinity 1260, 1262W
Both 12" woofers that handle a bit of power and can dig low if you make a 3 ft^3 (85 liter) or larger ported box for each driver.
I have been there.

Dave
 

GM

Member
Joined 2003
Greets!

I recommend beginning by reading up on dubstep mixing/mastering and recommended prosound speakers to get an idea of what sort of sub, amp power, EQ, XO point/slope is required, then moving on to speaker design if you still want to DIY: Dub Step music - Google Search

I'm guessing your budget and amp selection won't be nearly enough to satisfy you, at least not until you can afford more subs/amps to spread around the room to increase SPL and average out the room's modes: http://www.harman.com/EN-US/OurCompany/Innovation/Documents/White Papers/multsubs.pdf

GM
 
Right.

That amplifier won't be enough for what you want to do. You'll get reasonable volume, but not house-nudging.
On eBay, there's a Samson Servo 550. You couldn't build something with that power for the asking price.
Next up, you're going to need an active (pre-amplification) crossover. This can be as simple as a couple of high quality op-amps, assembled as 2nd order filters. Note: you'll need to be able to high-pass your Mission speakers. They cannot reproduce bass like these woofers will, so don't make them try.

On to the woofers.
I'm using a single JBL GTO1214 in a smallish sealed box. It goes rather loud (enough to make the walls shake, apparently). I propose a pair of them. One per side, each in either 40-50L sealed or 80-100L ported (tune from 28-20Hz respectively).

You could set off with one, and add a second one when money allows.

If you want loud and low, you have to move air. To do that, you need big cones and decent amounts of excursion. Those JBLs offer that at a decent price. There are cheaper woofers out there, but price to performance these are hard to beat.

For some reading, go to sound.westhost.com/articles.htm

Chris
 
That amplifier won't be enough for what you want to do. You'll get reasonable volume, but not house-nudging.
On eBay, there's a Samson Servo 550. You couldn't build something with that power for the asking price.
Next up, you're going to need an active (pre-amplification) crossover. This can be as simple as a couple of high quality op-amps, assembled as 2nd order filters. Note: you'll need to be able to high-pass your Mission speakers. They cannot reproduce bass like these woofers will, so don't make them try.

In the US, you can get a Behringer NU1000DSP for $258 shipped from amazon that will bridge to do about 700w RMS into a 4 ohm load. Plus it has a built in crossover and dsp. There is simply no way to match this with DIY that I am aware of.
 
Dubstep go all the way down to 20.

Build your own 2x12" TH (The Kraken 212 TH). 34 pages to read, I believe a few have built it. It has JBL car drivers which you can get second hand. I am not a huge fan of tapped horns, but this one will shake your house :)

You can build you own crossover, 24 dB/Octave 2/3-Way Linkwitz-Riley Electronic Crossover @ Elliott Sound Products .

Build your own amplifier as well : AMP15-PS-XP kit @ 41Hz , or a ready made one: Abletec ALC0300-1300. The 41Hz amp also needs a transformer and a box. You need to build a box for the Abletec.

The whole thing will take some time to build, so you have time to save the mone you need :).
 
Dubstep go all the way down to 20.

Build your own 2x12" TH (The Kraken 212 TH). 34 pages to read, I believe a few have built it. It has JBL car drivers which you can get second hand. I am not a huge fan of tapped horns, but this one will shake your house :)

You can build you own crossover, 24 dB/Octave 2/3-Way Linkwitz-Riley Electronic Crossover @ Elliott Sound Products .

Build your own amplifier as well : AMP15-PS-XP kit @ 41Hz , or a ready made one: Abletec ALC0300-1300. The 41Hz amp also needs a transformer and a box. You need to build a box for the Abletec.

The whole thing will take some time to build, so you have time to save the mone you need :).

With a tapped horn that large, you're going to need some sort or time alignment method.
 
Thanks folks,

I can stretch to the £70 for the JBL GTO1214 or the Infinity 1260. A 10" driver would be ok as well, as long as it goes down way low, but i just can't see any that go to 20 Hz. As it doesn't need to be that loud I guess that I could just stick the 12" in a sealed box and be happy. I did fancy a stab at a transmission line though, just for fun as the stuff I'd read said they were good. comments?

I could build my own amp and cross over.

Thanks again.
 
Yeah, on paper it has less effective motor strength, more inductance, so even with a bit more Xmax I would still choose the Infinity even if it cost a bit more. Cab loading wise, both sim audibly the same in a 20 Hz tuned reflex except the JBL needs a larger/longer vent, so to my way of thinking, another reason to choose the Infinity.

The 'burning' question then, is there a better 'bang/buck' to it?

GM
 
thanks again folks,

I was talking to the wood work teacher today who is pressing me into using Russian birch-wood ply. He can really smooth the edges down to give a nice zebra effect and stain it nicely. However he says 15mm but I get the impression that that would be too thin?

I'll probably go for the infinity then, but I'd just like to pass this by you as its cheaper, and says 20Hz+ where as the Infinity 1260w says 23Hz+:

The TS-W309D4 is recommended for enclosed use and is also available as a single voice coil model or as a a dual coil model for both enclosed and free-air use.
Pioneer TS-W309D4 Features:


  • Maximum input power 1.400 W
  • Nominal input power 400 W
  • Impedance 2ohms / 8ohms
  • Frequency response 20 - 220 Hz
  • Lowest resonance frequency 37 Hz
  • Sensitivity (1W/1m) 94 dB
  • Woofer size 30 cm
  • Woofer material IMPP Composite Seamless Cone
  • Voice Coil type Dual
  • Dual 4ohms voice coils: 2 or 8ohms Yes
  • Voice Coil bobbin type Aluminum, diam.2 inch (48mm)
  • Pole Yoke Type Extended and Vented pole yoke
  • Magnets Double-stacked, high power
  • Terminals: Push-type
  • Recommended sealed enclosure 24,1 - 49,5 litres
  • Cut-out Hole: 283 mm mm
  • Mounting Depth: 153,1 mm mm
  • Surround Dual Layer, Fiber Reinforced Elastic Polymer Surround


Infinity 1260W:

  • 12" 4-ohm subwoofer
  • polypropylene woofer cone with large-roll rubber surround
  • progressive spider design for excellent cone control
  • frequency response: 23-400 Hz
  • power range: 100-300 watts RMS (1,200 watts peak power)
  • sensitivity: 93 dB
  • top-mount depth: 6-3/8"
  • sealed box volume: 1.25 cu. ft.
  • ported box volume: 2.0 cu. ft.
  • is prettier than the Pioneer
Whatcha think?
 
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That ply ought to be okay if it's properly braced, to avoid the cabinet walls flexing.

GM, thanks for the comparison. I am curious, though - why would the JBL need the bigger vent?
Surely the extra 1mm of Xmax isn't enough.

If they'll both hit 20Hz, I'd take the JBL for the cast frame - not much risk of bending it while tightening screws.
 
Thanks about the ply. its only about £60 a sheet after tax. they also do an oak veneered ply which is cheaper that i might use. Cross bracing, gotcha.

I'm confused, I've checked the infinity in 3 different sources and its usable frequency only goes down to 23Hz, is it that is just close enough or is there something I'm missing? While we're on the subject can a human being destinguish between 20Hz and 23Hz?

Cheers
 
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