I need some sub in my life.
Years ago I had borrowed my friend's SVS SB3000 Micro and used it as a nearfield sub. My life was never the same after. Things have changed in the meantime, and now I would like to plan and build something to go with my DIY nearfield monitors (some Speedsters I'd built a while ago). These monitors can go low with correction, but distort at moderate volumes. Or it can play relatively loudly before the port chuffs. Either way, they could do with some relief below 80hz. And with that relief, the system can sound like nothing else for games, music, a quick TV show at the desk. I want that back.
While I believe the SVS will be difficult to beat in value, I believe in the value of high quality drivers, measurements and corrections.
Goals:
Time: A group delay less than 10ms for music (50hz and above)
Range: 30-100hz, with a non-reverberant cabinet to reduce distortion
Amplitude: A high dynamic range for music (~100dB @50hz), a moderate listening volume for deep bass (90dB+ @30Hz)
Constraints:
Size: A relatively small cabinet. A one foot cube is not going to meet my goals, but as small as possible for nearfield listening. In the triangle of size-->amplitude-->depth, I am cutting amplitude most definitely so I can have some sub
Budget: I would like the included parts to cost the equivalent of the SVS with all included equipment, about $1000
Performance: I would like this sub to far outperform the monitors I use, if possible. Port velocity is the constraint without subs, and that is not an issue I would like to repeat. Perhaps I will compensate for the loss of ports by including the addition of a second subwoofer in the future. Eventually I may be replacing these fairly good Speedsters with a monitor design that accompanies subwoofers more directly.
I did a little toying around with the enclosure tool and driver library VituixCAD has to offer. My estimated cabinet volume range was 20-40 liters based on my constraints and vents were looking quite long to keep the extension desirable. The Daytons were clearly happier in a ported box than sealed, so I landed a little unexpectedly on SB Acoustics. The SB29SWNRX-S75-6 has a low Fs and a high excursion, allowing it to handle some of the Linkwitz-Transforms and stock plate amp bass bosts I tested. A pair of them in Series ran 50V, minimum is 9.2 ohms. In parallel it simulated 25V at 2.3 ohms. I suspect the frequency response is optimistic, as the published measurements show -6dB rated sensitivity at 30hz.
Funny, I think I get the "box size doesn't matter" argument. When looking into alignments, I noticed that sealed boxes don't change the power handling at any size, unlike ports. So the only way to raise the dynamic range in a sealed alignment is by increasing the number of drivers. The only limitation is how to handle the back wave, hence bracing/force canceling. This is why the SVS SB3000 Micro is dual opposed, small, and plays so low and loud. It's also why I'm going to copy them.
The pair of these only needs about 250 watts to top out, and there are a plethora of amplifiers which will help me do that. I am leaning towards the Dayton 250W plate amp for it's class AB power, sealed chamber and verified power. No DSP plate amp has a high pass output for crossing to monitors, so I will need a DSP crossover solution, preferably with phase control. I should also get a calibrated omni microphone and stop using my cheap studio mic for EQ.
The Enclosure:
My thoughts on the enclosure are based on reading about high end KEFs and SVS cabinetry with regards to constrained layer damping and magnet bracing. KEF uses cloth as a damper between bracing to prevent vibration between rigid surfaces. These braces cross and lock with foam or cloth between instead of glue to prevent high frequency excitation. SVS braces their magnets to the box, likely to prevent sag, flex or reverb. My idea is to build braces which will relatively closely surround the magnets, and allow them to be coupled to the brace and one another with damping material. Whether this will be a benefit or if coupling the opposed subs will cause a new distortion could be a fun discovery. The planned material is 1/2" and/or 1" MDF. The sides will be one inch thick, with a 1/2" inset panel to reinforce the subwoofer baffles. These will have substantial dado cuts for the bracing to pass through, perhaps wide enough for the cloth damping technique or just wide enough to be glued. It's hard to say if stuffing will help, but let's assume I'll be stapling a thick sheet of damping to the inside walls and stuffing the remainder.
Some basic renderings:
Yes, the plate amp appears to go straight through the supports. I don't know if I need one or two braces, or if the dimensions of the plate amp are correct. Maybe I can just cut a slot in the brace consequence-free. Maybe I shouldn't use a plate amp. Maybe these drivers are wrong. It's what I'm here to work out.
The Bill:
2x SB29SWNRX-S75-6 $404
1x Dayton SPA250 $190
1x MiniDSP 2x4HD $225 // MiniDSP Flex $495
1x UMIK-2 + Tripod $210
1-2 MDF sheets, stuffing, screws, etc. ~$60-150
Totals: ~$850-1400
None of this is final and I am happy to receive constructive feedback or reports on the quality of any products mentioned. I have a few months before I plan to begin construction. It's been a few years, I can wait a little longer to get it all right.
Years ago I had borrowed my friend's SVS SB3000 Micro and used it as a nearfield sub. My life was never the same after. Things have changed in the meantime, and now I would like to plan and build something to go with my DIY nearfield monitors (some Speedsters I'd built a while ago). These monitors can go low with correction, but distort at moderate volumes. Or it can play relatively loudly before the port chuffs. Either way, they could do with some relief below 80hz. And with that relief, the system can sound like nothing else for games, music, a quick TV show at the desk. I want that back.
While I believe the SVS will be difficult to beat in value, I believe in the value of high quality drivers, measurements and corrections.
Goals:
Time: A group delay less than 10ms for music (50hz and above)
Range: 30-100hz, with a non-reverberant cabinet to reduce distortion
Amplitude: A high dynamic range for music (~100dB @50hz), a moderate listening volume for deep bass (90dB+ @30Hz)
Constraints:
Size: A relatively small cabinet. A one foot cube is not going to meet my goals, but as small as possible for nearfield listening. In the triangle of size-->amplitude-->depth, I am cutting amplitude most definitely so I can have some sub
Budget: I would like the included parts to cost the equivalent of the SVS with all included equipment, about $1000
Performance: I would like this sub to far outperform the monitors I use, if possible. Port velocity is the constraint without subs, and that is not an issue I would like to repeat. Perhaps I will compensate for the loss of ports by including the addition of a second subwoofer in the future. Eventually I may be replacing these fairly good Speedsters with a monitor design that accompanies subwoofers more directly.
I did a little toying around with the enclosure tool and driver library VituixCAD has to offer. My estimated cabinet volume range was 20-40 liters based on my constraints and vents were looking quite long to keep the extension desirable. The Daytons were clearly happier in a ported box than sealed, so I landed a little unexpectedly on SB Acoustics. The SB29SWNRX-S75-6 has a low Fs and a high excursion, allowing it to handle some of the Linkwitz-Transforms and stock plate amp bass bosts I tested. A pair of them in Series ran 50V, minimum is 9.2 ohms. In parallel it simulated 25V at 2.3 ohms. I suspect the frequency response is optimistic, as the published measurements show -6dB rated sensitivity at 30hz.
Funny, I think I get the "box size doesn't matter" argument. When looking into alignments, I noticed that sealed boxes don't change the power handling at any size, unlike ports. So the only way to raise the dynamic range in a sealed alignment is by increasing the number of drivers. The only limitation is how to handle the back wave, hence bracing/force canceling. This is why the SVS SB3000 Micro is dual opposed, small, and plays so low and loud. It's also why I'm going to copy them.
The pair of these only needs about 250 watts to top out, and there are a plethora of amplifiers which will help me do that. I am leaning towards the Dayton 250W plate amp for it's class AB power, sealed chamber and verified power. No DSP plate amp has a high pass output for crossing to monitors, so I will need a DSP crossover solution, preferably with phase control. I should also get a calibrated omni microphone and stop using my cheap studio mic for EQ.
The Enclosure:
My thoughts on the enclosure are based on reading about high end KEFs and SVS cabinetry with regards to constrained layer damping and magnet bracing. KEF uses cloth as a damper between bracing to prevent vibration between rigid surfaces. These braces cross and lock with foam or cloth between instead of glue to prevent high frequency excitation. SVS braces their magnets to the box, likely to prevent sag, flex or reverb. My idea is to build braces which will relatively closely surround the magnets, and allow them to be coupled to the brace and one another with damping material. Whether this will be a benefit or if coupling the opposed subs will cause a new distortion could be a fun discovery. The planned material is 1/2" and/or 1" MDF. The sides will be one inch thick, with a 1/2" inset panel to reinforce the subwoofer baffles. These will have substantial dado cuts for the bracing to pass through, perhaps wide enough for the cloth damping technique or just wide enough to be glued. It's hard to say if stuffing will help, but let's assume I'll be stapling a thick sheet of damping to the inside walls and stuffing the remainder.
Some basic renderings:
Yes, the plate amp appears to go straight through the supports. I don't know if I need one or two braces, or if the dimensions of the plate amp are correct. Maybe I can just cut a slot in the brace consequence-free. Maybe I shouldn't use a plate amp. Maybe these drivers are wrong. It's what I'm here to work out.
The Bill:
2x SB29SWNRX-S75-6 $404
1x Dayton SPA250 $190
1x MiniDSP 2x4HD $225 // MiniDSP Flex $495
1x UMIK-2 + Tripod $210
1-2 MDF sheets, stuffing, screws, etc. ~$60-150
Totals: ~$850-1400
None of this is final and I am happy to receive constructive feedback or reports on the quality of any products mentioned. I have a few months before I plan to begin construction. It's been a few years, I can wait a little longer to get it all right.
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It looks nice. Only thing I would suggest is for your bracing scheme to make good glued contact with the middle of the panels which are otherwise unsupported, rather than the corners which are already very strong. Also if your drivers have pole vents then those need room to breathe as well.
While I like the idea of a plate amp for simplicity and portability, it is possible the new TPA powered class D's would provide a better output in less space. It's mostly the reports of the Dayton SPA250 being underrated and overdesigned that appealed to me. The higher power SPA 500 class G is out of stock. The Yung plate amps exist in 300/500W, have a smaller footprint, but no switchable bass boost. Though they have a variable phase adjustment, which is a highly desirable feature in my experience. I haven't seen much on the SPA500, just the now discontinued SPA1000. As much as I'd like to burn Hypex money on all of my audio projects, it probably won't fit the budget.
I'm open to suggestions.
I'm open to suggestions.
Since you're already planning on a miniDSP 2x4HD, the additional boost and phase controls on the amp are surplus to requirements; all you need is clean power.
Personally I prefer passive subs and pro amps, for ease of construction/bracing, as well as reliability. Something like a Crown XLS 1500 would easily power a pair of your subs, and used ones can often be found locally at bargain prices.
Personally I prefer passive subs and pro amps, for ease of construction/bracing, as well as reliability. Something like a Crown XLS 1500 would easily power a pair of your subs, and used ones can often be found locally at bargain prices.
They look excessive in a good way. Some used seem to dip to $200. Are there any telltale signs of abuse to look for? I assume pro amps are designed to last and be repaired, but a new one is in excess of my budget. Even if it scales up with my eventual goal of two DO subs, my available living space may not scale up for some time to suit it.
I like it though. Gonna keep reading about them.
I like it though. Gonna keep reading about them.
With Crown XLS (I've bought a few over the years), I check that the cooling fan isn't caked in filth, although some dust is to be expected. Then power on and set to stereo mode, check that both channels work. Then press all three front panel buttons and check the rail voltages, temperatures, and for any fault codes. If that all looks okay, you should be good to go.
Once home, I open it up and vacuum the dust from around the heatsinks and fan.
I have made some revisions to the model, made each component a unique panel for consistent editing, and set up sheet cut diagram to pull measurements from once everything is finalized. There's enough room for a final window brace and a cross cut in the blank paneling for more reinforcement. The main brace could also be skeletonized somewhat in the future. Tough to say how I would actually cut this piece. Maybe I can get one of the nearby shops with a CNC machine to slice a sheet perfectly for me. Either way, there's room for a spare panel or two.
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Try modeling the Dayton RSS265. I used it in a 1.2 cf sealed box, it's quite a sub & needs only a modicum of DSP PEQ. It goes a bit lower at higher volume than the SBA. 14mm Xmax vs 11mm is the main functional difference. I use the SBA10s in my LX 521 clones & like them a lot but I'd go with the RSS265 next time, having heard what the can do.
Also consider Eric.A's 2x300W class D amps modules in the vendor's bazaar. $99, self powered, and 600W easily bridged. Tho you do need to house it, still a bargain & excellent in the sub amp role.
Note: don't know how much new tariffs will affect price. These come from China. But so do lots of things on your list.
Note: don't know how much new tariffs will affect price. These come from China. But so do lots of things on your list.
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Lots of things need to happen sooner than later because of this. I’m hoping existing stock and wavering actions from my government warrant a stalemate in the market for a while, but it’s hard to say. I’m hoping for the best, doing what I can while I can. It’s also possible the used market will have things for me.
A cheaper alternative to Mini DSP could be a Thomann t.Racks Mini DSP. Depending if there are some functions you require, eg. no biquad filters and no importing filters from REW in the t.Racks.
I'm using that for my 12" 32l closed subs and 15" coaxial tops, the dsp is good enough for basic use but nothing special.
I'm using that for my 12" 32l closed subs and 15" coaxial tops, the dsp is good enough for basic use but nothing special.
This would be nice if I were only equalizing the subwoofers to the room, but I am planning to correct the response with a linkwitz-transform. Likewise it needs to connect to my Mac platforms, my Linux platforms, and my Windows desktop if needed.
Just a quality 4-out DAC would be better, tbh. The source is currently a PC with EQAPO installed. I could run rephase if I had enough analog outputs worth trying. The MiniDSP 2x4HD just fits this requirement, with the Flex being the future-proof option. Even a DX7-style DAC would work if it had four outputs and distortion lower than my listening volume.
I ran a quick sim this morning to compare the Dayton and the SB. Simulations only matter for so much, especially since the SPL estimated appears very optimistic when comparing to the frequency response charts in the specs. Most of these subs appear 6-10dB below rated sensitivity in their advertised range.
It's worth considering that for a small increase in power, these can do the same as the SB subs. Both are good options, and the decision will likely come down to outside factors, like shipping, final price and the used market. Good pick, thanks @mikessi
It's worth considering that for a small increase in power, these can do the same as the SB subs. Both are good options, and the decision will likely come down to outside factors, like shipping, final price and the used market. Good pick, thanks @mikessi
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Given push-push and a pretty well thot out geometry, a simple 15-18mm quality plywood box would VERY likely domjust as well as the constrained layer — nothing wrong with diy overkill.
Your renders suggest MDF which is not a great speaker building material, and even less so for subwoofers.
How many are you buiding?
dave
(PS: i just skimmed the tread and looked at the pictures)
Given push-push and a pretty well thot out geometry, a simple 15-18mm quality plywood box would VERY likely domjust as well as the constrained layer — nothing wrong with diy overkill.
Your renders suggest MDF which is not a great speaker building material, and even less so for subwoofers.
How many are you buiding?
dave
(PS: i just skimmed the tread and looked at the pictures)
MDF is the plan, but I am also considering plywood. Nothing is set right now. I have time.
Currently I have the space for one sub, but eventually I would like two, and a miniDSP crossover would easily allow that.
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When investigating the Dayton subs, it occured to me that the existing box could fit a Dayton RSS315HO/HF. It's only a 25mm difference between the frame of the SB29 and the 315. I get twice the power handling, a significant boost in Xmax and some 3dB output increase. The baffle and bracing took very minimal adjustment, and the existing box would technically work. I've never seen a box so overdamped before, with a Q>1.1, but I believe in the power of the Linkwitz Transform, I guess.
This time the box is 1" thick paneling with 1/2" reinforcement. The baffle is 1.5" thick with the driver inset and a 1/2" chamfered protrusion to protect it from slamming into anything.
This time the box is 1" thick paneling with 1/2" reinforcement. The baffle is 1.5" thick with the driver inset and a 1/2" chamfered protrusion to protect it from slamming into anything.