Hi all, new to the forum here, so if there is a better spot for this post please let me know.
I am in the process of finishing a new entertainment space in my basement, and was thinking of building a custom sub to place behind the reclining chairs. I have a fair bit of flexibility in terms of size, and will build whatever enclosure works. The rest of the sonic duties will be handled by an Onkyo 7.1 receiver with PSB fronts and in-wall speakers for surround.
So I believe step 1 is deciding on electronic components. For example I see all kinds of amplifier options on Aliexpress: from naked class D boards costing $10 to plate amps costing $200 with built in crossover and AC power. I'm comfortable with a soldering iron and am willing/eager to learn new things to support this project. I'm also willing to listen to good advice of the sort "since this is your first serious build, just make your life easy and use approach X ..."
Open to options (ported / passive radiator, single vs. dual driver, single amp, dual amp, etc) and happy to "go away and do some reading kid" if anyone has resources to suggest.
Thanks, and looking forward to learning from these forums.
I am in the process of finishing a new entertainment space in my basement, and was thinking of building a custom sub to place behind the reclining chairs. I have a fair bit of flexibility in terms of size, and will build whatever enclosure works. The rest of the sonic duties will be handled by an Onkyo 7.1 receiver with PSB fronts and in-wall speakers for surround.
So I believe step 1 is deciding on electronic components. For example I see all kinds of amplifier options on Aliexpress: from naked class D boards costing $10 to plate amps costing $200 with built in crossover and AC power. I'm comfortable with a soldering iron and am willing/eager to learn new things to support this project. I'm also willing to listen to good advice of the sort "since this is your first serious build, just make your life easy and use approach X ..."
Open to options (ported / passive radiator, single vs. dual driver, single amp, dual amp, etc) and happy to "go away and do some reading kid" if anyone has resources to suggest.
Thanks, and looking forward to learning from these forums.
There are lots of designs that might work, so lets narrow it down a bit.
Questions:
- Budget?
- Actual maximum size?
- Low-frequency extension goal?
- Maximum SPL goal?
- How's your woodworking?
With regards to amplification, I'd look at Behringer iNukes (or the newer NX series) with silent fans fitted, and call it good. DIYing amps can be fun, but those amps put out plenty of power for subwoofer duties. Some people like them for main speaker use, but I find them a little "grainy" compared to nicer stuff.
Chris
Questions:
- Budget?
- Actual maximum size?
- Low-frequency extension goal?
- Maximum SPL goal?
- How's your woodworking?
With regards to amplification, I'd look at Behringer iNukes (or the newer NX series) with silent fans fitted, and call it good. DIYing amps can be fun, but those amps put out plenty of power for subwoofer duties. Some people like them for main speaker use, but I find them a little "grainy" compared to nicer stuff.
Chris
I see all kinds of commercial options around $250-400, so I'd want to hear a compelling reason to go north of there, especially if I'm investing a bunch of my own time in the project.
Around 190cm long x 50cm tall x 30cm deep. But I've got some leeway on the tall & deep dimensions, and I'd want to angle the front face, so it wouldn't be 30cm deep all the way from bottom to too. Let's call it 190L +/-
My existing fronts sound great but they're only a 6.5" driver. I'd like this sub to pick up those visceral frequencies that I believe are missing now. Not sure if you're looking for a quantified answer, and if so, my (possibly not that helpful) answer would be "20Hz"
Not sure if you're looking for a quantified answer, or something subjective like "I want to feel happy about the fact I built a sub, but I'm not looking to win any contests or knock **** off shelves"
Sometimes noteworthy for the wrong reasons, but I generally figure things out.
Since this box will be located behind our heads as we watch movies or listen to music, not sure how I feel about fans of any kind.
Just a rec, my Overdrive 10 may suit you, and is relatively straightforward to build too. It's posted in this forum. It's at the top end of your budget, but you can get stuff on sale if you watch for it.
I would suggest soft rubber feet for hard floors, and spikes for carpet.
There are of course many other designs available.
Have fun!
Wolf
I would suggest soft rubber feet for hard floors, and spikes for carpet.
There are of course many other designs available.
Have fun!
Wolf
If I were to make a recommendation on drivers, the Peerless SLS are great for money, XLS are really nice, and SDF maybe a step above those. The Dayton RSS woofers are loved by many and in a wide range of applications. If you want cheaper costs, I feel the Dayton DCS line might be your best bet.
Type of box? Ultimately this depends on the driver, but for thundering lows I would recommend a ported box. If you want a smooth extension that blends well with a room, then sealed might be better but boost might be required for thundering. If you want a sub that seems to get out of the way, does not excite room boom from 50-70Hz, blends well with the room, and still thunders down low; then a boosted PR-bandpass such as my Overdrive 10 is more your style. I've built quite a few subs, and this (shameless plug I know) sub impresses me the most of anything I've built per cubic inch.
Later,
Wolf
Type of box? Ultimately this depends on the driver, but for thundering lows I would recommend a ported box. If you want a smooth extension that blends well with a room, then sealed might be better but boost might be required for thundering. If you want a sub that seems to get out of the way, does not excite room boom from 50-70Hz, blends well with the room, and still thunders down low; then a boosted PR-bandpass such as my Overdrive 10 is more your style. I've built quite a few subs, and this (shameless plug I know) sub impresses me the most of anything I've built per cubic inch.
Later,
Wolf
Because you can do a lot better.
You'd fit a decent 15 in that sort volume with a 20Hz tune.
It gets very expensive to get below 20Hz at any decent SPL.
Far to suggestive to be much help.
Since this box will be located behind our heads as we watch movies or listen to music, not sure how I feel about fans of any kind.[/QUOTE]There is a simple and cheap fan mod and they are very quiet. The fans in them are designed for pro levels of heat which is much, much higher than you'll ever find in a domestic situation. Lots of power for the $ plus a powerful, easy to use DSP in the DSP version.
Personally, I would never bother with a plate amp in preference; poor power, low reliability and generally rubbish EQ etc.
Got to Data-Bass and look at existing designs to get some ideas.
One point you need to realise: your budget is at the lower end and the DIY value is not at it's best here.
Point two; where in the world are you?
Maybe my best bet is to buy a commercial sub for now, and revisit the idea of a DIY build sometime in the future.
Toronto area
I'd go with this sort of option, but get a well reviewed board from a good supplier, rather than the cheapest possible. If the woofer(s) will be close to your head, you really don't want a cheap amp that has a continuous buzz.
That's a big deal. I'm surprised nobody else has mentioned this: The closer the woofer is to your head, the louder it will seem. The power requirements of a nearfield speaker can be extremely low* compared to a normal build.
So you can use a much smaller amp.
Using a smaller amp means you can run regular woofers, rather than beefy, high powered subwoofers.
....therefore I'd suggest something like a pair of these
Dayton Audio DC380-8 15" Classic Woofer
+ a 24 volt power supply (e.g. an old laptop charger)
+ a decent class D amp** (look for good S:N ratio, and reviews that aren't from bots)
Parts cost (not including enclosure) should be < $200.
Build a simple sealed box (or 2) and position the drivers at head height, just behind the prime seats.
*Theoretically (in open air), each halving of distance gives +6dB, meaning you only need 1/4 as much power for the same subjective loudness. Dropping distance 4m --> 50cm means 800 watts --> 25 watts.
Other benefits of nearfield subs:
a) if the bass is lower in level, less of it will leak out to scare your cat / annoy neighbours.
b) better sound quality. You'll get lots of direct sound, and not much room sound / 'echo'.
c) nearfield bass measures differently, so I think your speakers will subjectively go lower than most simulations would predict. mh-audio.nl - Nearfield Measurement
But:
d) these benefits are only for listeners in the prime seat(s).
e) any enclosure where the sound is radiated from >1 point (bass reflex, tapped horn etc) will be harder to model than usual, because the distances between these points will be (relative to the listening distance) much larger than usual.
**I currently run a sub with a little DTA-120 amp (it delivers about 40 watts to each 15" woofer).
For a close listening position, with reasonably sensitive speakers, a little power should go a long way.
If you do, try before you buy. Put your ear right up to it - check that it is dead silent. No pops or clicks when gear is turned on and off, no low-level noise when running.
If it is going to be very close to your listening position, you don't want a cheap amp that has a continuous buzz.
Thanks Hollowboy.
I was thinking the drivers won't be at head level - they will be at butt level directly behind the viewers. But your overall comments about nearfield speakers are very helpful.
When you say bass reflex or tapped horn will complicate things due to multiple wave sources, does that extend to a single-ported dual-driver design?
I assume that with a nearfield sub, I'd also want to include some kind of pre-amp that allows me to adjust phase (as well as volume and low-pass frequency)?
I was thinking the drivers won't be at head level - they will be at butt level directly behind the viewers. But your overall comments about nearfield speakers are very helpful.
When you say bass reflex or tapped horn will complicate things due to multiple wave sources, does that extend to a single-ported dual-driver design?
I assume that with a nearfield sub, I'd also want to include some kind of pre-amp that allows me to adjust phase (as well as volume and low-pass frequency)?
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Nearfield is great. I speak from experience and they don't need to be at ear height. I've had a quad of ported 12" Shivas at one time, and a quad of sealed and EQ'd FTW21s. Otherwise I agree with all of HBs remarks in this regard.
Complte and utter rubbish, especially where the port and driver are very close together; at 20Hz, one wavelength is 17m long, and the two sources only need to be <1/4 wavelength apart to be considered the same point. This is a general rule, but applies even less at low frequencies where our hearing is even less sensitive.
That's why I suggested the iNuke DSP. You'll never build it's equivalent for the same $, not even close plus you get lots of EQ, delay etc as well as an easy interface, far, far more than any plate amp I've ever seen. And I've had a literal ton of them across my bench for repairs. Most are utter rubbish even from commercial designers like Klipsch. Some you can't get parts for and some replacement units are near the cost of the entire subs new. I've replaced several for friends with the iNuke.
My suggestion would be the Dayton UM15-22 in a 20Hz or so tuned enclosure and an iNuke DSP1000 with fan mod, ~$12.
This forum is fairly poor at subwoofers compared to the AVS DIY section.
If you have trouble modelling it, let me know.
It can't be "Complte" if you have to specify
I'm actually curious about this for my own purposes. I've got some ideas / some big old drivers (very low Fs but not much xmax) that might be good as nearfield subs.
Example A
Say I have an existing bass reflex box. It is a simple 60x60x60cm cube with driver and port on centres of opposite faces. The box models + measures well in the far field: the port and driver output sum to flat.
I decide to use this hypothetical box right behind my listening seat, so the woofer is 25 cm from my ears. The port would then have a roughly 130cm path to my ears, and the two sources would (I'm guessing) no longer sum flat.
My guesstimate is the port would be about 12dB down, relative to a far field test.
Example B
Say I have an existing bass reflex box. It is a simple 60x60x60cm cube with driver and port on centres on the same face. The box models + measures well in the far field: the port and driver output sum to flat.
I decide to use this hypothetical box right behind my listening seat, so the woofer is pointing at my right ear, and the port is pointing at my left ear.
I honestly don't know how that would sum / if it would be odd.
If position / measuring point doesn't matter, why is there always a bit of fudgework involved in nearfield measurements (adding port and driver outputs)?
And why does this paper exist?
Thiele, A. N., “Estimating the Loudspeaker Response when the Vent Output is Delayed”, Journal of the Audio Engineering Society, Vol. 50, #3, May 2002
That's an honest question - the paper is behind a paywall, and if I could access it, I might not understand it. Please thrill me with your acumen
Build a tapped horn.
Interesting...
Seems like an excellent use of the long, shallow space behind a home theatre sofa.
Thanks for posting. I've got some research to do.
The tapped horn could be great given you want the sub behind the sofa to achieve 20Hz movie rumbles. Its also efficient so you can save money on the driver and amp over a usual subwoofer and get the project in on your budget. Your issue with a tapped horn is that length is needed for lower frequency so you will need about 2500mm for good output at 20Hz.
In terms of fitting it behind the sofa with your wish for the front panel to slope back at the top, I havent seen anyone do that with a tapped horn but cant see why it couldn't be considered - you might want to ask in the tapped horn threads. It would be a smart use of space.
In terms of fitting it behind the sofa with your wish for the front panel to slope back at the top, I havent seen anyone do that with a tapped horn but cant see why it couldn't be considered - you might want to ask in the tapped horn threads. It would be a smart use of space.
So if I'm going to try out a tapped horn, I want to keep the cabinet as shallow (front to back) as possible. I think that means an 8" driver (or possibly two?)
Any suggestions for something affordable and readily available that would suit this application? I have a couple 7498E boards kicking around, and I have a 32V 600W power supply on order.
I assume that once I know the driver(s) I'm using, I'd use HornResp to figure out the parameters of the box.
Any suggestions for something affordable and readily available that would suit this application? I have a couple 7498E boards kicking around, and I have a 32V 600W power supply on order.
I assume that once I know the driver(s) I'm using, I'd use HornResp to figure out the parameters of the box.
This example is close to the dimensions you gave earlier (165 litre - 1850mmx450x345) and the driver is still available. It seems pretty well priced, considering Peerless is a well regarded brand, and it has quite a lot of excursion. In theory, you could modify the dimensions to make it 300mm deep, but in practice, I don't think that driver would fit
Tapped Horn Experiments
2 driver tapped horns work fine. The spud uses 2x8" and is very shallow.
THSpud | Danley Sounds Labs | Danley Sound Labs, Inc.
HR has a bit of a learning curve. Try it out, then post screenshots: a horde of tapped horn fans and HR gurus will spring to your aid.
Okay, I am leaning toward a tapped horn with dual 8" drivers. I have up to about 200L space to play with in the intended location for this sub (though something more compact is always welcome). Help me understand what makes a good driver in this application. For example I see these two reasonably-priced options with very different looking specs:
Skar Audio - VVX-8v3 | 8" 800 Watt Max Power Car Subwoofer
R3.8 | Soundstream
Skar Audio - VVX-8v3 | 8" 800 Watt Max Power Car Subwoofer
R3.8 | Soundstream
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