Not exactly DIY, but the same approach with stage subs

mk1981

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The most cost-effective way to add lots of high quality bass to a HT setup recommended here and elsewhere, is to make DIY subwoofers, getting largest diameter speaker available (15" or 18" if not larger), build an enclosure based on T-S parameters of the speaker and pair it with an outboard amplifier and a miniDSP.

The prospect of making an enclosure by myself is daunting. I don't have ready access to woodworking tools and fixing a mistake would be costly, so I was looking at the options available to me in Europe (sadly, I don't see premade subwoofer enclosures for home use, in contrast to the US).

I recently came across listings of lightly used or even unused (due to COVID) stage subwoofers. The price range is incredibly low like $150 for a pair of Wharfedale Pro SVP-18B up to $500 for a pair of Wharfedale Pro Delta X18B in perfect condition. The 18-incher in DLX series (released in between these two) is somewhere in between cost-wise.

Looking at Wharfedale's page for X18B here, the frequency response is 38 Hz-1.5 kHz ±3 dB, then goes down to 30 Hz at -10 dB. I figure if it's a major third down for each -7 dB, it would go to 24 Hz at -17 dB and just below 19 Hz at -24 dB, all at 99 dB. Pretty solid.
Looking at its manual, no reflex ports are visible, so it's probably a sealed speaker. The older model SVP-18B has three ports on the front, this one doesn't.

I won't be playing the subwoofer at 99 dB, I figure the peak SPL they ever reach is 100 dB, and will usually be played at no higher than 85 dB.

Anyway, aesthetics aside, I was thinking any of these large sub-bass units could be an excellent subwoofer in the home theater when paired with a 800 W amplifier and supplied through a miniDSP.

It seems like such an easy solution that begs to be paired with something like Behringer NX1000 or NX3000 amplifier and a miniDSP 2x4. A cosmetic cover would probably be necessary to make it living room-compatible, but it's not impossible.

What am I missing? Are DIY solutions, sometimes costing several times more per speaker, better in any tangible way, considering it's bass we're talking about?
 

Wayne A. Pflughaupt

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What am I missing?
It doesn’t get very low – 38 Hz is basically it’s usable extension. That’s fine for pro audio use, but not so great for a home audio subwoofer. If you can live with that, then you’ll be happy with it.


The prospect of making an enclosure by myself is daunting. I don't have ready access to woodworking tools and fixing a mistake would be costly, so I was looking at the options available to me in Europe (sadly, I don't see premade subwoofer enclosures for home use, in contrast to the US).
If you can live with cuts that aren’t perfectly straight, all you need is a jig saw and a battery-powered drill.

Why would a mistake be “costly?” How much does wood cost in Europe??

Regards,
Wayne
 

mk1981

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Yeah, it was later explained that this is actually a vented subwoofer, not a sealed one.

Wood is probably the same as in America. I guess it might even be cheaper (and less impacted by the price increases) because it's not used for construction as much.

Thing is, I can buy MDF in bulk or cut to my requirements. By bulk I mean they're large sheets that I can't really fit in a car (few people own a pickup truck, I sure don't), so buying pre-cut is the only way it can be done right.

Gluing the pieces together into a basic cube is not a problem. I guess I'd need a few clamps, nothing big.
Painting it requires consumables and very simple and inexpensive tools.
Screwing in feet and the speaker isn't a problem. Wiring it isn't a problem. Even making a grille isn't much of an issue (and I'd have to make a grille with children around).

The problem is cutting the large hole for the speaker (or speakers). The small hole for the socket is easy. It's the large one that's potentially a problem since it needs to be finished properly with an inset edge for the speaker to sit in. I couldn't seem to find this done as a service and I don't feel like spending several thousand on tools just to make a couple of subwoofers. Sadly, while there definitely were 15" and 18" subwoofers sold on the market, it seems none of them break since I'd expect at least a couple damaged ones to be resold just for the cabinet. No such luck.
 

Wayne A. Pflughaupt

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Messages
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Location
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More  
Preamp, Processor or Receiver
Yamaha CX-A5000 A/V Preamp / Processor
Main Amp
Yamaha RX-Z9 AV Receiver (as multichannel amp)
Universal / Blu-ray / CD Player
Denon DCT-3313 UDCI Universal Disc Player
Front Speakers
Canton Karat 920
Center Channel Speaker
Canton Karat 920
Front Wide Speakers
Realistic Minimus 7 (front EFX speakers)
Surround Speakers
Canton Plus D
Surround Back Speakers
Yamaha YDP2006 Digital Parametric EQ (front mains)
Front Height Speakers
Yamaha YDP2006 Digital Parametric EQ (surrounds)
Rear Height Speakers
Yamaha YDP2006 Digital Parametric EQ (sub)
Subwoofers
Hsu ULS-15 MKII
Other Speakers or Equipment
Adcom ACE-515 (for power management)
Video Display Device
Yamaha DT-2 (digital clock display)
Screen
Pioneer PDP-6010FD 60" Plasma TV
Remote Control
Stock Yamaha Remote
Streaming Equipment
Roku Express
Other Equipment
Audio Control R130 Real Time Analyzer
You don’t even need clamps. It should be screwed together anyway. I like using flat-head sheetrock screws because they easily countersink flush. Use lots of glue on assembly, it should be squeezing out everywhere. Easy enough to clean up the excess with a wet rag.

Cutting the hole for the speaker is no big deal. I’ve done it myself, and my carpentry skills are basic at best. The speaker you get should include a template you can trace on the wood. After that, it’s an easy cut with a jig saw. The speaker will come with a gasket that will give an airtight seal the speaker to the box I’m sure there are some DIY speaker building sites you can find with more tips.

Regards,
Wayne
 
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