Adjustable passive radiator series tuned 6th order.

Brother went on vacation and wanted his music for his trip, so this build is one hold for a few weeks. Did a project using a cheap Chinese 2 channel BT amplifier and some 6x9 speakers I had lying around instead of his build today.. Amp does about 30 watts rms x 2. Actually sounds pretty darn nice and is really loud with these high sensitivity speakers. Hank the hater is up in arms.
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Quick random question:
When you build an enclosure and utilize PRs, do you still use polyfill?
I always use polyfill in any sealed chamber that a sub motor sits in. Inside a vacuum, which is what a sealed chamber is, any air inside will be an adiabatic air mass. Basically the air will move, but the heat wont move and will sit where the heat is created, which is around the coil. Using polyfill helps create an isothermal air mass where heat is moved around with the air inside the vacuum. In theory, this should help dissipate heat more evenly inside the box and keep the coil cooler. I’ve always used it. A passive system might not need polyfill, since they are pushing and pulling opposite the sub, but I don’t see why you couldn’t use it. I used some in my passive radiator setup.
 
I always use polyfill in any sealed chamber that a sub motor sits in. I used some in my passive radiator setup.



Doing it this week. I have a stock Dodge Challenger Harmon Kardon subwoofer system. There are a pair of dual voice coil 10" subs. Strangely only 3 coils are wired. So I am thinking I will pull both 10s out, drop one beefier one in, and fill the hole with a passive radiator, after I load 'er up with some of that poly fill.

Now I need to find an amp with high level inputs. Looking into a few. Skar, NVX, and a few others.
 
Some say that the PRs on the same face may not be recommended, though Im not sure why. Anyone know the reasoning?

BTW any updates on the 6th order?

P.S. Was that a Kicker L7 QB8 that I saw in some of the earlier pics?
 
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Some say that the PRs on the same face may not be recommended, though Im not sure why. Anyone know the reasoning?

BTW any updates on the 6th order?

P.S. Was that a Kicker L7 QB8 that I saw in some of the earlier pics?
I blew out the radiator and haven’t bought any more to finish this project. It’s just difficult to design the box with enough room on the face for radiators and sub, but It seems to work well. Sound seems fine. I have an L7 12 in a 4th order bandpass, but the only 8 I have is an RDS audio.
 
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I blew out the radiator and haven’t bought any more to finish this project. It’s just difficult to design the box with enough room on the face for radiators and sub, but It seems to work well. Sound seems fine. I have an L7 12 in a 4th order bandpass, but the only 8 I have is an RDS audio.
Thats too bad, I was really looking forward to the innovative build. I thought those PRs by earthquake were almost indestructible under normal thresholds. Lesson learned for me is that vs vent a PR can for the most part get damaged. I have quite a few of the other Earthquake PRs unused yet, one of which seems like a concentric PR.

Curious, how did you blow out your PR and any other PR tips that you came across for use in a 4th/6th type design?
 
Thats too bad, I was really looking forward to the innovative build. I thought those PRs by earthquake were almost indestructible under normal thresholds. Lesson learned for me is that vs vent a PR can for the most part get damaged. I have quite a few of the other Earthquake PRs unused yet, one of which seems like a concentric PR.

Curious, how did you blow out your PR and any other PR tips that you came across for use in a 4th/6th type design?
I blew them out because the baskets get warped if you remove them too many times. Plastic baskets. The surround comes unglued from the edge. I used them in 4 different boxes with 3 different subs.
 
Some say that the PRs on the same face may not be recommended, though Im not sure why. Anyone know the reasoning?
I think this may be more of a home theater thing to just keep them from wanting to vibrate across the room by balancing them out. This may or may not be ******** or may only be an issue with a lighter weight subwoofer system. Best placement for subs and port/passive on the box in a vehicle is probably going to depend on the vehicle and figuring out which orientation is optimum will require testing.
 
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