In a quest for awesome bass, I've formulated this plan after some thinking.
Adire Tumult(old version which I have)
Adire ADA1200(which I just ordered last week)
Stryke18" passive radiator(perhaps 2 later, but we'll see how one does)
6cubic foot enclosure
I was going to simply use a ported box, but considering the length of port required to get infasonic tuning(between 10-16hz) I decided a passive radiator might be a better way to go even though it costs more.
I was looking at tuning right around 16hz in 6 cubic feet, but with a single passive it doesnt seem possible as the highest tuning allowed is 13hz. For two passives it is easily achieveable, but I dont exactly need 18liters of PR Vd! A single passive does run out of excursion at ~15hz with 1200watts of power, but considering how often there is content that low in the signal, and how often I turn things up all the way, I dont think it will be a problem.
So what I'm going to do is buy one passive radiator next friday. In the mean time I'm going to build a 6cubic foot sealed box which will house the Tumult and ADA amp for now until the passive arrives and I'll cut a hole to fit the PR. I think I'll eventually get a 2nd PR, but probably not for another couple weeks.
Construction will begin tonight and pics coming soon! Stay tuned
Any comments are welcome also
Adire Tumult(old version which I have)
Adire ADA1200(which I just ordered last week)
Stryke18" passive radiator(perhaps 2 later, but we'll see how one does)
6cubic foot enclosure
I was going to simply use a ported box, but considering the length of port required to get infasonic tuning(between 10-16hz) I decided a passive radiator might be a better way to go even though it costs more.
I was looking at tuning right around 16hz in 6 cubic feet, but with a single passive it doesnt seem possible as the highest tuning allowed is 13hz. For two passives it is easily achieveable, but I dont exactly need 18liters of PR Vd! A single passive does run out of excursion at ~15hz with 1200watts of power, but considering how often there is content that low in the signal, and how often I turn things up all the way, I dont think it will be a problem.
So what I'm going to do is buy one passive radiator next friday. In the mean time I'm going to build a 6cubic foot sealed box which will house the Tumult and ADA amp for now until the passive arrives and I'll cut a hole to fit the PR. I think I'll eventually get a 2nd PR, but probably not for another couple weeks.
Construction will begin tonight and pics coming soon! Stay tuned
Any comments are welcome also
I assume you mean a low pass filter. The ADA amps have Twin cascaded second order filters Q=0.707 adjustable from 35 to 110 Hz. The crossover network can be defeated, 2nd, or 4th order.
If you mean a subsonic filter, no I'm not planning to use one.
greater than 90% of the time I wont be going anywhere near full power. The other 10% of the time I'm not going to be playing anything with strong content below 30hz, much less 14hz where excursion reaches 34mm at 1200watts. It should not be needed
Simply put, I am careful not to abuse my speakers
Simply put, I am careful not to abuse my speakers
I had a question... if anyone knows this it would be very helpful
What is the mounting depth on the stryke PR-18?
I emailed stryke a few days ago and havent gotten a reply yet. I'm guessing is probably not deeper than 6 or 7 inches, but its hard to tell from just a picture. I need to know so I can tell what kind of cutouts need to be done in the bracing. Does anyone know?
What is the mounting depth on the stryke PR-18?
I emailed stryke a few days ago and havent gotten a reply yet. I'm guessing is probably not deeper than 6 or 7 inches, but its hard to tell from just a picture. I need to know so I can tell what kind of cutouts need to be done in the bracing. Does anyone know?
You can have a fold in the bassreflex channel, that does not harm very much. So you could build it out of wood and use the enclosure walls for it.
I don't think John checks the old Stryke Audio email accounts anymore, but if you email him at sales@aespeakers.com then you might get a more expedient response.
No ports for this one... A port with sufficient cross section will be very long and large. It will have a low pipe resonance frequency, and will also take up a good deal of room in the enclosure. The passive radiator approach will provide deep tuning without chuffing or pipe resonace while doing it in a minimal enclosure size
Your sub sounds very cool!
Have you considered using the Linkwitz transform circuit that is built into your ADA1200?? I bet that you will still have more than enough power and then you could do away with the passive radiator and port.
nate
Have you considered using the Linkwitz transform circuit that is built into your ADA1200?? I bet that you will still have more than enough power and then you could do away with the passive radiator and port.
nate
i could use the linkwitz for sealed box, BUT if anything I'd probably just EQ it flat, and well I prefer the PR with ~7db gain in efficiency at 16hz and excursion reduction. And the 18" PR's look cool
Absolutely. I was just wondering if you considered the LT. I've never tried it.
Best of luck!
Nate
Best of luck!
Nate
I can understand why you are using a PR with the Tumult! Definately if it was to be a port, then not a slot port, that would just get too big. You would probably need a pair of 150mm vents, which would have to run external to get them tuned low enough.
One thing to keep in mind with PRs is that you don't want to use all of their VD, or even close. Remember a PR is a driver minus a motor, hence the output from the PR will have compression related to increased suspension stiffness with excursion. ie for a given PR, the more VD you have, the less excursion required and the less compression you will have. Unfortunately, the engineering of PRs will not normally match the Tumult with its flat BL curve and I believe also fairly flat suspension curve.
The VD of a passive is rated to the suspension limit, but do you think it's a good idea to be using them to their mechanical limit? Probably not a good thing for SQ!
Also consider things like having PRs in opposing pairs balances the moving mass. Mostly relevant to keep the box from moving, unless its so big that this won't be an issue.
To me this seems a bit ironic - you want a vented/PR alignment for the extra output, yet if this will be used for movies, not using a rumble filter will potentially lose you more output than using a sealed box with EQ will. If you are prepared to give up that much low end potential SPL, then why not just save the money spent on PRs and use a sealed box!
One thing to keep in mind with PRs is that you don't want to use all of their VD, or even close. Remember a PR is a driver minus a motor, hence the output from the PR will have compression related to increased suspension stiffness with excursion. ie for a given PR, the more VD you have, the less excursion required and the less compression you will have. Unfortunately, the engineering of PRs will not normally match the Tumult with its flat BL curve and I believe also fairly flat suspension curve.
The VD of a passive is rated to the suspension limit, but do you think it's a good idea to be using them to their mechanical limit? Probably not a good thing for SQ!
Also consider things like having PRs in opposing pairs balances the moving mass. Mostly relevant to keep the box from moving, unless its so big that this won't be an issue.
To me this seems a bit ironic - you want a vented/PR alignment for the extra output, yet if this will be used for movies, not using a rumble filter will potentially lose you more output than using a sealed box with EQ will. If you are prepared to give up that much low end potential SPL, then why not just save the money spent on PRs and use a sealed box!
BassAwdyO said:
That's right, 70cm will give sth like 200 Hz if I'm not totally wrong, you have to filter 4th order to get control of it.
Hey guys... dont be hating on the passive radiator approach
no matter how you look at it a ported or passive radiator is going to get me >7db @ 16hz. A sealed box of 6 cubic feet runs out of xmax before it even takes 1200watts at 16hz. A ported or passive radiator enclousre doent run out of excursion until 14hz with 1200watts.
The passive radiator should not suffer from linearity problems until below 30hz,... And well how much linearity below 30hz is required? Most subs have high non-linearity below these frequencys, so a passive radiator cant be smearing the sound any more really. The excursion reduction of the driver and low Fs of the pasisve would probably lower distortion?
no matter how you look at it a ported or passive radiator is going to get me >7db @ 16hz. A sealed box of 6 cubic feet runs out of xmax before it even takes 1200watts at 16hz. A ported or passive radiator enclousre doent run out of excursion until 14hz with 1200watts.
The passive radiator should not suffer from linearity problems until below 30hz,... And well how much linearity below 30hz is required? Most subs have high non-linearity below these frequencys, so a passive radiator cant be smearing the sound any more really. The excursion reduction of the driver and low Fs of the pasisve would probably lower distortion?
There are 2 problems I see.
1. Tuned that low it is likely to sound terrible for music, loose and sloppy and you can't stuff a PR like you can a port.
2. For HT the group delay is going to be so high that when you see the dinosaur step here on the video you'll hear, rather feel, the footstep like it was 10 or 20 meters further away. While it may feel cool and go unnoticed, it still won't be accurate.
Make some cool external ports, if cool is important. Then figure out a cool mechanism for closing them up.
Just my 2 cents.
1. Tuned that low it is likely to sound terrible for music, loose and sloppy and you can't stuff a PR like you can a port.
2. For HT the group delay is going to be so high that when you see the dinosaur step here on the video you'll hear, rather feel, the footstep like it was 10 or 20 meters further away. While it may feel cool and go unnoticed, it still won't be accurate.
Make some cool external ports, if cool is important. Then figure out a cool mechanism for closing them up.
Just my 2 cents.
BA, can you not see the contradiction here I mentioned?
You want the extra output so you spend money on a PR but you don't want to use a rumble filter because you don't need the extra output?!
If you have more output than you want, then why not save your money and use a sealed box?
If you want the ultimate in value for money, SPL and extension then use a very large low tuned vented box.
If you want the above but either can't achieve noise free ports, or want it smaller, then use at least a pair of PRs.
Convention seems to be to use a pair of 18" PRs for a single 15" high excursion driver, but my initial guess is that four might be appropriate for the Tumult.
I'd expect distortion performance to improve due to reduced excursion.
You want the extra output so you spend money on a PR but you don't want to use a rumble filter because you don't need the extra output?!
If you have more output than you want, then why not save your money and use a sealed box?
If you want the ultimate in value for money, SPL and extension then use a very large low tuned vented box.
If you want the above but either can't achieve noise free ports, or want it smaller, then use at least a pair of PRs.
Convention seems to be to use a pair of 18" PRs for a single 15" high excursion driver, but my initial guess is that four might be appropriate for the Tumult.
I'd expect distortion performance to improve due to reduced excursion.
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