For the last couple months I've been on a research rampage learning everything there is to know about DIY subwoofers(it's kind've what I do when I get interested in something...) and currently I'm in approximately 15' x 20' x 8' room in an apartment, so SPL is not a concern because I'd get evicted immediately. My main concerns are that every note be hit which since I listen to pretty much every type of music means at least the low 20's for extension and hopefully lower and that it have very tight quick bass so that it can keep up with my magnepan 1.6's. So far I have a QSC USA 1300 to power the subs and a minidsp to crossover and par EQ, and I'm also running my magnepans through the minidsp to par EQ the midbass. I was worried it would impact SQ through the speakers, and there was a slight noticeable difference, but I value smooth midbass response over the slight impact in SQ.
So what I have learned in my long long searching is to keep excursion as low as possible, to go sealed if ultimate SQ is your goal and go ported if HT and deeper extension is your ultimate goal. So to get ultimate SQ you want multiple subs to smooth response, excursions well below Xmax, a very well braced enclosure aaaand...
That's it? Is that really all it takes to make a good high quality sounding subwoofer? I haven't really found much else besides very rarely mentioned things like balanced subs that point in opposite directions to minimize box vibrations, but what I generally see is those have litte noticeable impact on SQ. Is there something I'm missing?
So far my design is to build 2 subs, each with a Dayton audio RSS315HO-44 due to its relatively good excursion, while having a relatively low Vas to be able to put in a decently small box. I would put them each in a box that is about 14 in by 18 in by about 24 in going along the walls behind my magnepans. Then I would have a port at the bottom tuned to about 18hz which gives me way more SPL then I would ever need to below the frequencies I wanted, then I could seal the port and run it in sealed mode, which would be great in the approximately 3 Cu Ft enclosure and would be an optimal size for sealed. Then I could use the minidsp to EQ the low end so that it is flat to a lower frequency(essentially a linkwitz transform). I've also considered instead of using the Dayton to use an infinity Kappa 100w.9 which has a vas of only about 15L or so, can't remember off the top of my head. This would make the 3 cuFt box essentially an IB enclosure since it would be about 5x Vas.
So my question is, is that it? Is that all it takes to make a good subwoofer? And how important is it for a sealed sub to be in a large enclosure? I've heard that a large sealed/IB gives you the lowest distortion bass because it takes the least amount of power to get a certain amount of bass, but then I've also heard all that really matters is keeping Xmax down, so as long as you can pump the power into a small enclosure you'd be fine. I just want someone to sort of clear up what makes a good sounding sealed subwoofer. And also whether the Dayton is a better idea or the infinity.
Also as a sidenote I'll only be using these subs up to 40-50 hz at which point the magnepans will take over.
So what I have learned in my long long searching is to keep excursion as low as possible, to go sealed if ultimate SQ is your goal and go ported if HT and deeper extension is your ultimate goal. So to get ultimate SQ you want multiple subs to smooth response, excursions well below Xmax, a very well braced enclosure aaaand...
That's it? Is that really all it takes to make a good high quality sounding subwoofer? I haven't really found much else besides very rarely mentioned things like balanced subs that point in opposite directions to minimize box vibrations, but what I generally see is those have litte noticeable impact on SQ. Is there something I'm missing?
So far my design is to build 2 subs, each with a Dayton audio RSS315HO-44 due to its relatively good excursion, while having a relatively low Vas to be able to put in a decently small box. I would put them each in a box that is about 14 in by 18 in by about 24 in going along the walls behind my magnepans. Then I would have a port at the bottom tuned to about 18hz which gives me way more SPL then I would ever need to below the frequencies I wanted, then I could seal the port and run it in sealed mode, which would be great in the approximately 3 Cu Ft enclosure and would be an optimal size for sealed. Then I could use the minidsp to EQ the low end so that it is flat to a lower frequency(essentially a linkwitz transform). I've also considered instead of using the Dayton to use an infinity Kappa 100w.9 which has a vas of only about 15L or so, can't remember off the top of my head. This would make the 3 cuFt box essentially an IB enclosure since it would be about 5x Vas.
So my question is, is that it? Is that all it takes to make a good subwoofer? And how important is it for a sealed sub to be in a large enclosure? I've heard that a large sealed/IB gives you the lowest distortion bass because it takes the least amount of power to get a certain amount of bass, but then I've also heard all that really matters is keeping Xmax down, so as long as you can pump the power into a small enclosure you'd be fine. I just want someone to sort of clear up what makes a good sounding sealed subwoofer. And also whether the Dayton is a better idea or the infinity.
Also as a sidenote I'll only be using these subs up to 40-50 hz at which point the magnepans will take over.
What makes a subwoofer sound good is putting it in a room with well controlled room modes. 🙂 If your listening room is bounded by stud partitions with drywall, you may be OK as these will absorb standing waves by vibrating slightly. But in a smallish room with plastered brick walls, you may never get good bass without acoustic treatment or digital room correction (or ideally both)
Since you have the MiniDSP, you can dial up some parametric EQ for room correction. This tends to make the fine details of subwoofer frequency response irrelevant, since you will be correcting it along with the room. You just need plenty of output with low distortion. A sealed box would probably still be a better solution than a vented one, as the response falls off slower at low frequencies and is more suited to correction by EQ.
"Tight quick bass" is not a function of the subwoofer, it is a property of the whole system when everything is working just right. It comes from good integration with the main speakers and good control of the room modes.
Since you have the MiniDSP, you can dial up some parametric EQ for room correction. This tends to make the fine details of subwoofer frequency response irrelevant, since you will be correcting it along with the room. You just need plenty of output with low distortion. A sealed box would probably still be a better solution than a vented one, as the response falls off slower at low frequencies and is more suited to correction by EQ.
"Tight quick bass" is not a function of the subwoofer, it is a property of the whole system when everything is working just right. It comes from good integration with the main speakers and good control of the room modes.
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Hi,
5 x Vas is just a very bad design, no better than 2 x Vas.
You want at the most about Vas of box volume.
Optimum sealed volume of the Dayton is not 3cuft,
its about 1 cuft sealed, and about 2 cuft for vented.
"OPTIMUM CABINET SIZE
(DETERMINED USING BASSBOX 6 PRO HIGH FIDELITY SUGGESTION)
Sealed Volume 0.49 ft.³ Sealed F3 47 Hz
Vented Volume 1.36 ft.³ Vented F3 27 Hz"
My numbers are based on a different definition of optimum.
If SPL is not an issue, always go sealed and stuffed with a Qbox
of about 0.6, and after EQuing out any room mode peaks, go for
a mildly peaking 2nd order high pass for low boost, say at 20Hz.
Its unlikely you'll need any more EQ, due to room gain effects.
If you are limited to low overall SPL's, as I am in a block of
flats, I've built EQ (mainly low bass) into my preamplifier.
rgds, sreten.
5 x Vas is just a very bad design, no better than 2 x Vas.
You want at the most about Vas of box volume.
Optimum sealed volume of the Dayton is not 3cuft,
its about 1 cuft sealed, and about 2 cuft for vented.
"OPTIMUM CABINET SIZE
(DETERMINED USING BASSBOX 6 PRO HIGH FIDELITY SUGGESTION)
Sealed Volume 0.49 ft.³ Sealed F3 47 Hz
Vented Volume 1.36 ft.³ Vented F3 27 Hz"
My numbers are based on a different definition of optimum.
If SPL is not an issue, always go sealed and stuffed with a Qbox
of about 0.6, and after EQuing out any room mode peaks, go for
a mildly peaking 2nd order high pass for low boost, say at 20Hz.
Its unlikely you'll need any more EQ, due to room gain effects.
If you are limited to low overall SPL's, as I am in a block of
flats, I've built EQ (mainly low bass) into my preamplifier.
rgds, sreten.
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Additional thoughts:
Ported systems are resonant systems. While "steady-state" response may look fine, personally, I find most ported systems seem to miss something. My 4 10" subs are sealed, and somewhat small overall. DSP eq gets me as deep as I need to go. I recently went from mono to stereo on the system, but can't say it made much difference. My room is larger than yours, more than double the volume, so you may not need nearly as much woofer. I do play loud sometimes....
Ported systems are resonant systems. While "steady-state" response may look fine, personally, I find most ported systems seem to miss something. My 4 10" subs are sealed, and somewhat small overall. DSP eq gets me as deep as I need to go. I recently went from mono to stereo on the system, but can't say it made much difference. My room is larger than yours, more than double the volume, so you may not need nearly as much woofer. I do play loud sometimes....
This.
The Linkwitz speakers, already mentioned by jacq, seem perfect for what you need.
Make the woofer only section of the LX521, add basstraps and you'll be fine.
Did you ever own dipole bass system from LinkwitzLab? I have for 15 years now. I have yet to fine a more accurate bass reproduction system that integrates so nicely with the rest of the spectrum. It ended décades of fidling in search of good bass reproduction. Of course you do not get the seductive viscéral impact of a closed box but the neighbors don't eighter or much much less as by vélocity it does not travell to room structure as much as per pressure driven alignements.
But bottom line it's all a matter of taste.
Regards
Jacq.
This is not always true. A front loaded bass horn sub or a tapped horn sub, if properly designed, will probably have lower cone movement for the same SPL as a sealed box.
The problem with a horn is that it does have a cutoff frequency, where it no longer helps, and to get to the 20s, you need a BIG horn.
Very much so, unless they're "aperiodic" resistive ports, then transient response can be quite good and critically damped,
with a much improved impedance curve near the resonant frequency.
Look into Bill Fitzmaurice sub designs,we just finished a pair of his Table Tuba's to help out our LaScalla's below 100hz. My search is over of course we all have our own needs and listening preference. Good Luck in your search.
So what I'm getting then is good bass comes from good room control and having a large output headroom and sealed for best sq.
Then I think I'm going to go dual infinity kappa 100w.9's because they have the best price to output ratio and also can fit in a smaller size which is always nice. They'll probably fall off earlier but eq can fix that.
How much would room treatment cost and how much space would it take up? I don't currently have any acoustic treatment but can't seem to figure out where to start without spending an arm and a leg and covering all my walls...
Also I found somewhere that cabin gain begins at speed of sound/(2 x the longest distance in the room) which for me would be about 25hz and then it's 12db/octave below that. That would mean if I can make a sealed sub flat down to 25hz in an open space it will be flat further down in my room since sealed subs fall off at 12db/octave. Wouldn't that mean my bass response would just stay flat?
Then I think I'm going to go dual infinity kappa 100w.9's because they have the best price to output ratio and also can fit in a smaller size which is always nice. They'll probably fall off earlier but eq can fix that.
How much would room treatment cost and how much space would it take up? I don't currently have any acoustic treatment but can't seem to figure out where to start without spending an arm and a leg and covering all my walls...
Also I found somewhere that cabin gain begins at speed of sound/(2 x the longest distance in the room) which for me would be about 25hz and then it's 12db/octave below that. That would mean if I can make a sealed sub flat down to 25hz in an open space it will be flat further down in my room since sealed subs fall off at 12db/octave. Wouldn't that mean my bass response would just stay flat?
Hi,
There is more to it than that, the Dayton drivers have good motors.
You can't simply judge a driver on claimed Xmax. What are
the specs of the Kappa's your going on ? planned boxes ?
FWIW lowbass room gain depends on the room being airtight.
rgds, sreten.
There is more to it than that, the Dayton drivers have good motors.
You can't simply judge a driver on claimed Xmax. What are
the specs of the Kappa's your going on ? planned boxes ?
FWIW lowbass room gain depends on the room being airtight.
rgds, sreten.
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