I've got an IDMAX that I'm gonna be using for a HT/music sub. I was thinking of a 4 cu/ft box tuned to 18-20 hz. Thats calls for some seriously big ports, so I was thinking of trying a passive radiator setup. Would a single 15" PR be sufficient? Where can a person find a decent inexpensive PR?
You will need probably two PRs.
You can get them here...
http://www.acoustic-visions.com/~acoustic/products/passive_radiators/
You can get them here...
http://www.acoustic-visions.com/~acoustic/products/passive_radiators/
Cal Weldon said:
For car use, I thoughrally agree, and have only had it sealed in my car. However, in home, I don't think i'm gonna get enough room gain to make it flat to 20hz
simon5 said:
two ya think? May I ask why? I did some calculations, and it seems that the added cone area and xmax of the PR (specifically the Adire) that a single 15" would be fine. I was thinking of the Adire, because I calculated it out to needing around 650g, and the Stryke/AE are all too heavy. The Adire weighs 285, and I could add the rest. Am I on the right track?
Well, it depends, if you want to stay under 250W RMS, then one Adire Audio PR15 is enough.
If you want to use the full power your subwoofer can take in a 4 cu.ft box (875W RMS) then you need two Adire Audio PR15.
I checked and yes, you should use Adire Audio PR15 in your application with 875W RMS, unless price is an issue.
If you want to use the full power your subwoofer can take in a 4 cu.ft box (875W RMS) then you need two Adire Audio PR15.
I checked and yes, you should use Adire Audio PR15 in your application with 875W RMS, unless price is an issue.
simon5 said:
I've got 900WRMS to play with. How did you come up with that 875W number?
Anyways, if I need 2 PR, I calculated it out to 864g. Stryke has got a 1050g radiator on sale for $45, is there a way to lighten it? Price isn't a death blow, but i'd like to get by at the lowest cost I can
thanks
Well, I'm using WinISD Pro.
In a 4 cu.ft box NET internal volume, tuned to 18.77 Hz, with two Adire Audio PR15 with 975g added mass on each, you can use 875W RMS, if you use more, you'll have slight overexcursion of your woofer. Probably OK, it's only 25W, but it's not a good thing to run a woofer higher than the linear excursion on the long term.
You can use Stryke Audio PRs, but they will go down to 17 Hz when your woofer can do 16 Hz, so you might damage your PRs at 16 Hz without hearing it because the woofer will still be ok. You would need to buy two SA-PR15-1050 and add 260g to each one.
That's why I recommend using Adire Audio PR15 in that high power application if you're using an amplifier that can output 900 real watts RMS. The Adire Audio PRs are capable of going down to 13.75 Hz in this application, so you'll have the PRs protected by the ugly sound your woofer will make when driven in overexcursion, well before the PRs excursion limit is reached.
In a 4 cu.ft box NET internal volume, tuned to 18.77 Hz, with two Adire Audio PR15 with 975g added mass on each, you can use 875W RMS, if you use more, you'll have slight overexcursion of your woofer. Probably OK, it's only 25W, but it's not a good thing to run a woofer higher than the linear excursion on the long term.
You can use Stryke Audio PRs, but they will go down to 17 Hz when your woofer can do 16 Hz, so you might damage your PRs at 16 Hz without hearing it because the woofer will still be ok. You would need to buy two SA-PR15-1050 and add 260g to each one.
That's why I recommend using Adire Audio PR15 in that high power application if you're using an amplifier that can output 900 real watts RMS. The Adire Audio PRs are capable of going down to 13.75 Hz in this application, so you'll have the PRs protected by the ugly sound your woofer will make when driven in overexcursion, well before the PRs excursion limit is reached.
simon5 said:
I've just got WinISD beta. Anyways, since your calculating power is much higher than mine, if I got a pair of Adire PR15's, how heavy should I make them? Whats my optimal tuning freqency?
Also, I don't understand why the Adire is better than the Stryke, and I don't understand why I would add weight to the Stryke. Oh, and I most likely will have the amp turned down most of the time, but thats the maximum power I would send to the sub.
Thanks a lot!
Get WinISD Pro alpha, it's better overall than the old WinISD beta.
Well, the optimal tuning frequency choice is yours. It's a compromise between maximum power and group delay.
I could tune it a bit higher so you could use the full 900W of power you got.
To tune to 18.77 Hz, like I said, you would need to add about 975g to each PR.
The Adire is better, mostly because you have 31mm excursion versus 25mm excursion.
You could add 935g to each PR, so you got a nice 19 Hz tune, you can use the full power of your amplifier, so 900W. I guess that's the best compromise.
You need to add weight to the Stryke Audio PR, if you don't it will be tuned too high, at about 21 Hz.
Well, the optimal tuning frequency choice is yours. It's a compromise between maximum power and group delay.
I could tune it a bit higher so you could use the full 900W of power you got.
To tune to 18.77 Hz, like I said, you would need to add about 975g to each PR.
The Adire is better, mostly because you have 31mm excursion versus 25mm excursion.
You could add 935g to each PR, so you got a nice 19 Hz tune, you can use the full power of your amplifier, so 900W. I guess that's the best compromise.
You need to add weight to the Stryke Audio PR, if you don't it will be tuned too high, at about 21 Hz.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.