passive radiator help on a 6th order

[Jroo 10+ year member]

A few months ago someone was nice enough to model 4 MCM subs in a 6th order.

MCM Audio Select 8'' High Excursion Woofer - 120W RMS 4ohm | 55-2421 (552421) | MCM Audio Select

They were cheap enough and I figured why not. I was kicking around the idea of running 4 in an isobaric 6th order and he came up with the following specs.

Vf: .25ftⁿ

Fb: 60Hz

Vent: 3" (7.06in²) X 18.55"

Vr: .75ftⁿ

Fb: 30Hz

Vent: 3" (7.06in²) X 25.47"

As modeled, that box goes down at 73Hz on the top but it also goes down at 28Hz on the bottom.

I was looking at the ports and the port length and thought about trying passive radiators instead of running traditional ports. Now, since I have never tried passive radiators, I need some help picking out the size and also the weight each needs. Is there anyone out there that has experience and would lend me a hand picking the radiators that work?

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[wew lad 5,000+ posts]

you may want to try diyma or a more sq oriented forum

 

[CSCStang]

I've built a few enclosures with pr's and you'll need one 10" pr for each 8" sub.

 

[wew lad 5,000+ posts]

I've built a few enclosures with pr's and you'll need one 10" pr for each 8" sub.

you feeling better yet? hopefully your shoulder is leaving you alone

 

[CSCStang]

you feeling better yet? hopefully your shoulder is leaving you alone

I find out when surgery is on May 10th....finally....

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[Papermaker85 5,000+ posts]

A few months ago someone was nice enough to model 4 MCM subs in a 6th order.
MCM Audio Select 8'' High Excursion Woofer - 120W RMS 4ohm | 55-2421 (552421) | MCM Audio Select

They were cheap enough and I figured why not. I was kicking around the idea of running 4 in an isobaric 6th order and he came up with the following specs.

Vf: .25ftⁿ

Fb: 60Hz

Vent: 3" (7.06in²) X 18.55"

Vr: .75ftⁿ

Fb: 30Hz

Vent: 3" (7.06in²) X 25.47"

As modeled, that box goes down at 73Hz on the top but it also goes down at 28Hz on the bottom.

I was looking at the ports and the port length and thought about trying passive radiators instead of running traditional ports. Now, since I have never tried passive radiators, I need some help picking out the size and also the weight each needs. Is there anyone out there that has experience and would lend me a hand picking the radiators that work?

if you doing isobaric(i personally wouldn't) adding a radiator defeats the purpose really.

when your choosing a passive radiator you want to make sure the radiator has at least 125% of the total displacement of the driver/s you're using also make sure its linear travel as well..

i wouldn't go iso and i wouldn't use PRs for this alignment. but if you do chose the right alignment and PRs to you can get good results.

https://www.madisoundspeakerstore.com/approx-10-subwoofers/seas-sl26r-d1003-10-passive-radiator-mate-to-l26roy/

 

[wew lad 5,000+ posts]

I find out when surgery is on May 10th....finally....
Sent from my SCH-I605 using Tapatalk

my grandfather was having a pretty similar problem although im sure yours is worse because hes in his 80s. shot him up with some of that stuff that makes it easier to move, not sure what the name of it is not a pain killer but a kind of liquid that eases movement of the bone in the joint. he was able to get most of it resolved with physical therapy and a good massage therapist.

good luck man health is important

 

[CSCStang]

my grandfather was having a pretty similar problem although im sure yours is worse because hes in his 80s. shot him up with some of that stuff that makes it easier to move, not sure what the name of it is not a pain killer but a kind of liquid that eases movement of the bone in the joint. he was able to get most of it resolved with physical therapy and a good massage therapist.
good luck man health is important

Cortisone.

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[macsdad 10+ year member]

Cortisone shots, I have had them in my knee. Hope you finally get some relief stang.

 

[ciaonzo 5,000+ posts]

There is an added degree of complexity when designing and constructing/tuning a PR alignment versus a standard vented alignment. This will be severely compounded when attempting a 6th order bandpass with PR's. Standard 6th order with conventional vents is difficult enough to fine tune.

You will need some excellent modeling software and lots of patience when actually tuning that device.

 

[Papermaker85 5,000+ posts]

Cortisone.
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I used to pitch back in my younger days. i had no cartilage left in my throwing sholder by the time i was 20. man that was a bad bad pain. when you can't lift your arm past your waste without wanting to choke someone that is not a good feeling.

what happened to your arm money?

 

[CSCStang]

I used to pitch back in my younger days. i had no cartilage left in my throwing sholder by the time i was 20. man that was a bad bad pain. when you can't lift your arm past your waste without wanting to choke someone that is not a good feeling.what happened to your arm money?

Work injury. Mri shows two tears in muscle and a torn tendon. Doc says he'll fix the rotator while he's in there as well.

 

[adulbrich 5,000+ posts]

I used to pitch back in my younger days. i had no cartilage left in my throwing sholder by the time i was 20. man that was a bad bad pain. when you can't lift your arm past your waste without wanting to choke someone that is not a good feeling.what happened to your arm money?

You strike me as more of a catcher //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[Papermaker85 5,000+ posts]

You strike me as more of a catcher //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

id smoke your lame ***..

 

---------- Post added at 03:10 PM ---------- Previous post was at 03:09 PM ----------

 

Work injury. Mri shows two tears in muscle and a torn tendon. Doc says he'll fix the rotator while he's in there as well.

****. hope all goes well money

 

[adulbrich 5,000+ posts]

id smoke your lame ***..

I bet you would want to smoke my ass, you peter-puffer!