Where are the passive radiators?
Wanting a good 15" up to $650.
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Dude - I tried to figure out how to fit twin 18 PRs (2x15 PR was not enough excursion for 2x12SQL Active) in a 2.2 cuft box and there's simply not enough space inside the box.
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I never model those, since most people don't need them, if they do need them someone else can model it.
A 6 foot port seems like it needs some space too.
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Oh it does and that's the reason the 15s work better (easier?) ported than the 12s. I've yet to have anybody tackle the 12s ported in a SQ alignment - they always end up sealed or ported at 32 Hz.
I've designed two different boxes for 12s ported (a single and a dual) but in both cases they went sealed.
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Do they go sealed or ported @32 because that is where everyone does it?
or because that is where it sounds best?
And the driver also has a preference for sealed or ported?
My main point was that if someone is going ported, and they have a 6’ Howitzer barrel to keep it from chuffing, and they are also unsure of the port tuning freq… Then the only rational answer there is, “PASSIVE RADIATOR”.
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Sealed cause they found out that the output they wanted was plenty with sealed.
Ported at 32 was because that was the point at which the port size became manageable for them and what they'd "heard" was the best... 😞 and in one case what they already had which was a total failure as the box separated an hour after they fired it up! LOL
The driver has a preference for sealed but only slightly, like 55/45 on the EBP Calc...
You and I agree about the PR setup and I'm seriously considering doing a really complicated enclosure that would use cleat clamps to hang on the rear seatbacks in my Jeep with Dual SQL12s mounted externally and an 18" PR between them...
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I want the SQL 12" by SI... What size box should I put it in tuned at 32hz? I want to go ported for sure.
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1.5cuft doesn't look right to me.
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The SQL12 "wants" 1.358 cuft tuned to 25.5 Hz (F10 = 19Hz) but porting a box that small that deep results in the port volume taking up more space than the enclosure. The port needs to be 6" Diameter x 81" Long...
Raising that to 32 Hz but keeping the box size the same results in a 50" Long port and a +3dB hump in the response at 37 Hz with F10 of 22.5 Hz - the bigger the box gets from this the bigger the hump becomes.
By the time you get to 2.5 cuft and 32 Hz (25" port length) the peak becomes +6dB at 34Hz with F10 of 23Hz.
Major Boom Box by this point... but if all you want is maximum boom and you're used to the 40-42Hz prefab boxes with Skar Subs then you'll be very pleased as the SQL stomps on them in this situation. I've put SQL12s in prefab boxes purchased from Amazon and had very pleased teenage boys booming away in their squatted trucks. All of this is why we keep looking for ways to make a Passive Radiator work, the SQL12 is simply tailored to such small enclosures that there's not enough baffle space for the PRs.
Here's an example of a properly tuned Ported Enclosure for the SQL12 - this is a top-down cut-a-way view of the enclosure that's 14" tall (1.2 cuft at 26.6 Hz Slot Ported) so it's not impossible to do correctly:
![309401]()
Raising that to 32 Hz but keeping the box size the same results in a 50" Long port and a +3dB hump in the response at 37 Hz with F10 of 22.5 Hz - the bigger the box gets from this the bigger the hump becomes.
By the time you get to 2.5 cuft and 32 Hz (25" port length) the peak becomes +6dB at 34Hz with F10 of 23Hz.
Major Boom Box by this point... but if all you want is maximum boom and you're used to the 40-42Hz prefab boxes with Skar Subs then you'll be very pleased as the SQL stomps on them in this situation. I've put SQL12s in prefab boxes purchased from Amazon and had very pleased teenage boys booming away in their squatted trucks. All of this is why we keep looking for ways to make a Passive Radiator work, the SQL12 is simply tailored to such small enclosures that there's not enough baffle space for the PRs.
Here's an example of a properly tuned Ported Enclosure for the SQL12 - this is a top-down cut-a-way view of the enclosure that's 14" tall (1.2 cuft at 26.6 Hz Slot Ported) so it's not impossible to do correctly:
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I will be using a slot port that will be 2" x 10" x 20" with 2.25cuft tuned at 32hz
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Nick at stereo integrity told me the SQL 12" will work tuned at 32hz but only a max size of 2.0ft3 on the box.
Have you considered using a PR?
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No I want a ported box.
How is a PR not a ported box?
(It is not a sealed box)
That 50” long, and winding, port seems like something one would use to IQ test a rat with.
And a 6” diameter x 81” long port seems like another ideal good candidate for a PR.
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I am doing a box thats 2.0ft3 after all displacements with a slot port thats 2" x 10" x 22.5" long (inside box) tuned at 32hz
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I was surprised as well. Might be a typo for the 15". The 15" HST is asking for 50in^2 but so is the 18" HST so thats weird as well....
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