Hey Y'all.
I put together what I think would be a great enclosure for my Dayton Titanic 12" mkIII. Its been living in an old JBL enclosure power by a BASH 500. Please let me know if I missed anything here.
I entered the driver into WinISD
The only thing that was different from the spec sheet was Sd. It autocalculated and manually entering from the spec sheet would caused driver invalidation.
WinISD liked 130 liters tuned to just under 20 hz, SPL at 500 watts rms, 45 deg angle, 3 meters away.
Made this in sketchup to match:
Heres cone excursion and port velocity:
Looks like I'll need to filter under 20hz, but i have a DSP to help out.
Does that all check out? Did i make any mistakes?
I put together what I think would be a great enclosure for my Dayton Titanic 12" mkIII. Its been living in an old JBL enclosure power by a BASH 500. Please let me know if I missed anything here.
I entered the driver into WinISD
The only thing that was different from the spec sheet was Sd. It autocalculated and manually entering from the spec sheet would caused driver invalidation.
WinISD liked 130 liters tuned to just under 20 hz, SPL at 500 watts rms, 45 deg angle, 3 meters away.
Made this in sketchup to match:
Heres cone excursion and port velocity:
Looks like I'll need to filter under 20hz, but i have a DSP to help out.
Does that all check out? Did i make any mistakes?
It'd require more power to get the same SPL. Whether the driver will comfortably accept the extra power will vary.
If you're going to be running it hard, I'd build something as efficient as possible so the driver absorbs minimal power. If you only care about lower listening levels, then using some DSP boost on a smaller cabinet can make a lot of sense.
Chris
If you're going to be running it hard, I'd build something as efficient as possible so the driver absorbs minimal power. If you only care about lower listening levels, then using some DSP boost on a smaller cabinet can make a lot of sense.
Chris
I probably wont be running it to hard, I probably have the amp level set at 50% in the current enclosure.
That said, the design has a pretty small foot print. Going from 130 liters to 90 liters takes off 8 inches of height... not sure what good saving that 8 inches would do.
Would probably be better to make the box ideal, then use the DSP for any room effect or things WinISD didn't/couldn't account for.
That said, the design has a pretty small foot print. Going from 130 liters to 90 liters takes off 8 inches of height... not sure what good saving that 8 inches would do.
Would probably be better to make the box ideal, then use the DSP for any room effect or things WinISD didn't/couldn't account for.
I suppose I was thinking to geometrically.
Thanks chriss661 and BPFanatic. I'll switch it over to an L port.... I'm embarrassed, i have a degree in aerospace engineering
Hi GM, do you have a link or diagram for this? I'm doing a design for a driver with similar specs and have being playing around with Hornresp looking at a MLTL to see what difference there is over a basic ported design. There doesn't seem to be much difference but I might be looking at the wrong thing.
Greets!
No, not really; I mean in its base form it's just a shelf vent that's angled to create a 1/8 parabolic horn, though some folks flare the opening, but for subs this just increases normally unwanted port HF. Historically the throat [St] = [Sd/8] with taper typically 10:1 and its length a bit shorter than an axial 1/8 WL due to its large mouth/terminus end correction.
That said, I managed to miss this, so a horn vent's super low vent mach, minor peaking at [Fb] is wasted in your app, i.e. just EQ it a bit: I probably wont be running it to hard.
Re MLTL: for most apps here, its impact on vent damping is minimal, basically meaning the cab doesn't need as much internal damping. You can achieve the same by 'critically' damping a BR's vent,, i.e. using an impulse test to damp the vent's pipe harmonics with cloth/whatever tightly stretched over it. Pre software 'click' test: Click Test | GM210 | Flickr
For higher tuned apps where the cab doesn't need to be so long is where it excels since all we're doing is increasing height/volume to decrease vent system bulk. Of course one can fold a long, low tuned pipe, but most folks want 'simple'.
That said, high [Vas] drivers tuned as low as 20 Hz can work well in ~60" high cabs, so slowly becoming more popular among the vintage Altec, etc., crowds.
GM
No, not really; I mean in its base form it's just a shelf vent that's angled to create a 1/8 parabolic horn, though some folks flare the opening, but for subs this just increases normally unwanted port HF. Historically the throat [St] = [Sd/8] with taper typically 10:1 and its length a bit shorter than an axial 1/8 WL due to its large mouth/terminus end correction.
That said, I managed to miss this, so a horn vent's super low vent mach, minor peaking at [Fb] is wasted in your app, i.e. just EQ it a bit: I probably wont be running it to hard.
Re MLTL: for most apps here, its impact on vent damping is minimal, basically meaning the cab doesn't need as much internal damping. You can achieve the same by 'critically' damping a BR's vent,, i.e. using an impulse test to damp the vent's pipe harmonics with cloth/whatever tightly stretched over it. Pre software 'click' test: Click Test | GM210 | Flickr
For higher tuned apps where the cab doesn't need to be so long is where it excels since all we're doing is increasing height/volume to decrease vent system bulk. Of course one can fold a long, low tuned pipe, but most folks want 'simple'.
That said, high [Vas] drivers tuned as low as 20 Hz can work well in ~60" high cabs, so slowly becoming more popular among the vintage Altec, etc., crowds.
GM
Thanks for your reply 
. Yes, a horn for the port is probably not worth pursuing. I have done a bit more modelling in hornresp and found that there is some advantage (keeping total box dimensions the same) in going with a folded mltl:
- Keeping the same port area it allows me to shorten the port to fit along one wall, rather than going around the corner
- The shorter port pushes the first port resonance up past 200 Hz
- The fold partition provides some useful bracing
- Can be easily tuned with stuffing in the "wide end" of the line (the volume above the fold partition in the attached diagram)
The OP might want to look at this as an option.
. Yes, a horn for the port is probably not worth pursuing. I have done a bit more modelling in hornresp and found that there is some advantage (keeping total box dimensions the same) in going with a folded mltl:- Keeping the same port area it allows me to shorten the port to fit along one wall, rather than going around the corner
- The shorter port pushes the first port resonance up past 200 Hz
- The fold partition provides some useful bracing
- Can be easily tuned with stuffing in the "wide end" of the line (the volume above the fold partition in the attached diagram)
The OP might want to look at this as an option.
Attachments
Well, the city I live in got devastated by a derecho (land hurricane). So I haven't been on in a bit. But I decided to go for the build with the materials I had. I needed a break from chain sawing and calling insurance.
My plywood was less than straight. But building material is scarce after the storm Needs some more filler sanding before finish. But it sounds great and didn't cost me anything.
It's not louder then before but way way deeper and it vanishes sound wise. You cant tell the bass isn't coming from the mains. I think it's a big sound quality upgrade. And as a bonus it shakes my house with inaudibly low bass.
My plywood was less than straight. But building material is scarce after the storm Needs some more filler sanding before finish. But it sounds great and didn't cost me anything.
It's not louder then before but way way deeper and it vanishes sound wise. You cant tell the bass isn't coming from the mains. I think it's a big sound quality upgrade. And as a bonus it shakes my house with inaudibly low bass.
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