Two DIY Subwoofer builds, suggestions and ideas?

[whista]

Hello Audioholics, new on the forum but have some DIY background. I've got plans to build my first real sub! I want some decent extension and punch, but I'm limited on space and money.

I live in Sweden so driver choices are somewhat limited and more expensive than in the US. But the idea is a sub with a single 12 or 15" driver with a well designed ported enclosure smaller than 5.5 cu ft. I live in an smallish apartment, so a single sub is the way to go right now. It will be used for music ~60% and movies ~40%.

Things I already own: Inuke 1000, Mini-DSP.

Sub #1. The driver I've got my eyes on currently is the Dayton Titanic 12" MkIV in a ~4 cu. ft cabinet tuned to ~22Hz via a slotted port. I wish I could afford the 18" 460HO driver but that's outside my pricerange by far here in Sweden. Does this sound like a fair idea to you guys? Any other drivers I should be looking at in that pricerange?

Sub #2, This one is for a friend who just needs some bass extension. I bought a single Infinity 1260W on a sale, figured putting it in a 2-2.1 cu. ft ported box tuned to ~22hz would make a decent budget sub for the money?

I'm a carpenter by trade and have built several speaker projects before so the build itself should pose no problems.

Would be very thankful for any advice, I'm by no means experienced with subwoofer constructions other than the basics.

 

[jinjuku]

The Dayton would be my choice out of the two.

 

[whista]

The Dayton would be my choice out of the two.

Thank you for the reply, sorry if I was vague in my explanation. I'm building two subs, one for me which is meant to be a sub with decent SPL and pretty good punch. That's the one I'm considering the Titanic for.

Sub #2 is a freebie-build for a friend since I got the driver close to free. Asking on opinions on both constructions.

 

[rojo]

For sub 1, the tuning is too low. You should tune so the excursion null occurs at the driver's Fs. I think a 3.2 cu. ft. enclosure tuned to 28.25Hz would better suit that driver. Can you get the Dayton HO series driver, either 12" or 15", for around the same price as the Titanic? I think the Titanic would be better suited for car audio.

For sub 2 I'll have to look for the t/s params when I get to a PC.

Sent from my LG-VS980 using Forum Fiend v1.3.1.

 

[whista]

For sub 1, the tuning is too low. You should tune so the excursion null occurs at the driver's Fs. I think a 3.2 cu. ft. enclosure tuned to 28.25Hz would better suit that driver. Can you get the Dayton HO series driver, either 12" or 15", for around the same price as the Titanic? I think the Titanic would be better suited for car audio.

For sub 2 I'll have to look for the t/s params when I get to a PC.

Sent from my LG-VS980 using Forum Fiend v1.3.1.

Thank you for the reply, the lower than fs tuning frequency of 22hz was chosen because of the ugly hump in response when tuned at 28, a lower tune evened out the response nicely and gave much needed support around 20hz. Was that the incorrect approach?

I've been trying to get my hands on a 390HO, but it's easier said than done it seems.. is it a worthwhile driver to invest in if I manage to find one?

Thank you for your time, greatly appreciated.

EDIT: It appears there might be a reseller that can get me the Reference 390HO-4 for 2/3 of the price of a titanic 12".

 

[rojo]

Yeah, subs tuned below the driver's Fs don't sound as good as with tuning at Fs. It's better to look for a driver with a lower Fs.

How about the Eminence Lab 12 or the Creative Sound Solutions SDX12? Bygg Din Bas appears to be a distributor for CSS drivers in Sweden. That driver models extremely well in a ported box with excellent infrasonic extension (especially with room gain). Or you could do a 3 cu. ft. sealed box like mine, and EQ the bottom end. I'm thoroughly pleased with this configuration.

Your model of the Infinity 1260w isn't too bad. You lose about 5dB at 22Hz from using such a small box, though. If you could do a 4 cu. ft. box it'd be better. I actually think this driver looks better suited for your original plans for the Titanic. I recommend a 2nd order high pass filter at 20Hz to prevent over-excursion.

 

[whista]

Yeah, subs tuned below the driver's Fs don't sound as good as with tuning at Fs. It's better to look for a driver with a lower Fs.

How about the Eminence Lab 12 or the Creative Sound Solutions SDX12? Bygg din bas appears to be a distributor for CSS drivers in Sweden. That driver models extremely well in a ported box with excellent infrasonic extension (especially with room gain).

The Lab12 is nowhere to be found and ByggDinBas shut down their buissness last month. No decent way of getting the CSS-woofers in Sweden anymore. But like I said, the 390HO4 appears to be obtainable now.

The SDX12 was prohibitly expensive in Sweden anyhow... I could get at least two 390HO-4's for the price of a single SDX12 here.

 

[rojo]

The Dayton 15" HO is my favorite option. If you can do anywhere from a 3.5 to a 4.5 cubic foot box (4.5 giving the flattest response) tuned around 24Hz, you'd have a great sub.

 

[whista]

Hello again, sorry for the late reply. Been a busy weekend to say the least.
It appears I had incorrect data on the Infinity and 390HO Sub from the shop. I've revised the simulation with data from reliable WinISD sources.. Guess that's a cause for the confusion on my part, don't trust the information the shop supplies I guess.

Anyhow I've run some sims with the suggested volumes and tunes for the 390HO and got some questions. 3.5 cu ft with 24-25Hz tune seems to have a reasonably low group delay and response, over excursion takes place at ~20Hz at 300 watts, 18Hz at 200 watts... A much needed high pass filter @17Hz seems to do the trick, it increases group delay but it's within tolerance I guess?

Increasing size of the box to 4.5 cu and/or lowering the tune 2Hz seems to a few dB increase at 20dB and offer better extension and little flatter response at the cost of higher group delay and of course a larger box. How big of a deal is the group delay in reality? Is it worth it for the extra extension? for me a slightly smaller box with lower group delay seems like a decent offering, but I'm loosing a few dB at 20Hz, but the gap narrows down the further down you go in frequency.

Oddly enough, the Infinity 1260W seems to keep up very well with the Dayton in simulations, especially considering the smaller box/driver size and price difference. Or am I missing something? I revised my simulations on that driver too and found that your tune and box size was much more correct and made a whole lot of sense when I had the right data. I apologize for the slip-up on my side!

Any other ideas are most welcome.

 

[rojo]

...A much needed high pass filter @17Hz seems to do the trick, it increases group delay but it's within tolerance I guess?

TLS Guy tells me that group delay is what it is. I've seen other resources claiming that Hz * ms <= 400 is a worthwhile target to aim for. I'm afraid I don't have sufficient experience to confirm or refute either assessment. In this situation, though, I wouldn't put much consideration into how EQ and a subsonic filter affects group delay. Unless you've got bass traps and other acoustic treatments in your room, any room interactions will probably make the minutiae of group delay a moot point.

Increasing size of the box to 4.5 cu and/or lowering the tune 2Hz seems to a few dB increase at 20dB and offer better extension and little flatter response at the cost of higher group delay and of course a larger box. How big of a deal is the group delay in reality? Is it worth it for the extra extension? for me a slightly smaller box with lower group delay seems like a decent offering, but I'm loosing a few dB at 20Hz, but the gap narrows down the further down you go in frequency.

Consider that WinISD models anechoic response. With room gain, whatever rolloff you see will be much less pronounced. My sealed sub starts rolling off in the 40's; but with EQ house curve and corner loading, Funkenspelunkin shakes my room and pressurizes my ears. Between your iNuke's DSP and your miniDSP, I think you've got the response curve covered. You might as well go with the smaller enclosure.

 

[lsiberian]

Hello again, sorry for the late reply. Been a busy weekend to say the least.
It appears I had incorrect data on the Infinity and 390HO Sub from the shop. I've revised the simulation with data from reliable WinISD sources.. Guess that's a cause for the confusion on my part, don't trust the information the shop supplies I guess.

Anyhow I've run some sims with the suggested volumes and tunes for the 390HO and got some questions. 3.5 cu ft with 24-25Hz tune seems to have a reasonably low group delay and response, over excursion takes place at ~20Hz at 300 watts, 18Hz at 200 watts... A much needed high pass filter @17Hz seems to do the trick, it increases group delay but it's within tolerance I guess?

Increasing size of the box to 4.5 cu and/or lowering the tune 2Hz seems to a few dB increase at 20dB and offer better extension and little flatter response at the cost of higher group delay and of course a larger box. How big of a deal is the group delay in reality? Is it worth it for the extra extension? for me a slightly smaller box with lower group delay seems like a decent offering, but I'm loosing a few dB at 20Hz, but the gap narrows down the further down you go in frequency.

Oddly enough, the Infinity 1260W seems to keep up very well with the Dayton in simulations, especially considering the smaller box/driver size and price difference. Or am I missing something? I revised my simulations on that driver too and found that your tune and box size was much more correct and made a whole lot of sense when I had the right data. I apologize for the slip-up on my side!

Any other ideas are most welcome.

I strongly suggest you go with the Dayton. They are very capable drivers and well worth the extra cost. Even a 12" is gonna deliver exceptional bass when properly tuned. That said I won't port my sub in an apartment so I went with a TC Sounds driver and sealed it. If you plan to do a lot of moves make sure you use cabinet grade plywood.

FWIW tuning around Fs is only one alignment type there are others and they have their followings. I'd not worry about group delay it's a wild goose chase IMO.

 

[whista]

TLS Guy tells me that group delay is what it is. I've seen other resources claiming that Hz * ms <= 400 is a worthwhile target to aim for. I'm afraid I don't have sufficient experience to confirm or refute either assessment. In this situation, though, I wouldn't put much consideration into how EQ and a subsonic filter affects group delay. Unless you've got bass traps and other acoustic treatments in your room, any room interactions will probably make the minutiae of group delay a moot point.


Consider that WinISD models anechoic response. With room gain, whatever rolloff you see will be much less pronounced. My sealed sub starts rolling off in the 40's; but with EQ house curve and corner loading, Funkenspelunkin shakes my room and pressurizes my ears. Between your iNuke's DSP and your miniDSP, I think you've got the response curve covered. You might as well go with the smaller enclosure.

I'll just let the group delay be whatever it seems to be then. I've got some acoustic treatment, but it's not over the top. Rather basic actually...

Yeah, I know the response is anechoic and counting on room gain to give me headroom enough for flatten the response curve properly. I'll begin with basic design for the sub tomorrow after midsummer, see how it turns out. Seems I need double 4" ports or a nice slotted port to make sure I avoid chuffing noises.

Thanks you for the feedback.

I strongly suggest you go with the Dayton. They are very capable drivers and well worth the extra cost. Even a 12" is gonna deliver exceptional bass when properly tuned. That said I won't port my sub in an apartment so I went with a TC Sounds driver and sealed it. If you plan to do a lot of moves make sure you use cabinet grade plywood.

FWIW tuning around Fs is only one alignment type there are others and they have their followings. I'd not worry about group delay it's a wild goose chase IMO.

I will do so, the Infinity design is just for a friend who needs some more omph in the bottom end. Why no ported sub in your apartement? Neighbours to take into account?

I'll not move too much. I already have MDF laying around I was planning to use. Yeah, I've heard that as well and made some basic EBS designs before and they turned out pretty good. So I figured that lowering the tuning a bit to assist where the woofer had issues due to over excursion was a decent enough idea. But hey, I'm just an happy amateur when i comes to subwoofer design. Thanks again for the input!

 

[lsiberian]

Slotted ports give you plenty of air, brace the sub better, and are normally cheaper.

If you fold the port I suggest using the average between the outer and inner wall. If you have the latest .net framework and windows I have a program around here you can use to help get the dimensions dialed in. I definitely suggest you get the best sub driver you can even if you need to hold off a couple months.

there are numerous ways to build a speaker box the method I've use the most is simple butt end joints with corner and pipe clamps with titebond. TLS Guy rabbets each board with a 1/4" rabbet which creates a fantastic 1/4" space for a quarter round.

I know another guy who builds the frame with a rabbeted 2x2 and then lays the panels into the frame. I plan to try out that one on my next build.

Remember you will need an amp and a crossover. For a crossover the minidsp will work just fine.

 

[whista]

Hello again, I've been designing an enclosure, cutting MDF and aquiring a Dayton RSS390HO Driver.
I've got the latest .net framework installed so that's not an issue, I'd love to try out your program.

I will be doing a fairly simple braced butt end joints build with internal bracing and double baffles, I've got the MDF cut to the millimeter so it'll be a simple thing to put together in the coming days. I could go for a rabbeted cabinet as I have the tools but for this sub-build I don't see the need.

I traded the Inuke away due to various reasons, so now I'm stuck without an amplifier. Any suggestions on a fairly cheap amp up for the job? It'll get replaced in about half a year when the boring cold season starts to bore me and christmas comes along. Used is not an issue here.