EVA has a point. when you disconect the other speakers and listen just to the sub (assuming it is crossed over somewhrere below 100hz) most of the time what you hear is uner whelming. There are rare exceptions. Nontheless, if yoy listen to all the speakles but try it with and without the sub the difference can be sustantial. A good sub doesn't do much but what does it does well.
Why?I havent done any sims, but I'd guess the Qtc doesnt get below .5(critically dampened). I see no point in making sealed boxes as small as possible[/qoute]
I think due to the size of the box and the port size, there is no rear dampening.
No, I don' think he should make the box smaller. However, if you take the port out altogther, the recommended box size for infinite baffle will need to be even smaller than the recommended size for a bass-reflex box.
Try to make changes that won't cost you too much money first.
eag, if you are going to compensate for the internal volume, use something solid that won't make noise of its own. Use something like 2x4s, just make sure they don't rattle around.
What will it hurt to try to reduce the size? Some time and a couple of bucks?
It's a beauty of a box. Be a shame to take it apart.
if u want kickbass make boxes with good transient response (small group delay)
try to respect this formula: f*gd<400
for this u will need to simulate that box (if u have t/s parameters)
group delays smaller then 10ms@50hz or 3-4ms@80hz are perfect and u will "hear" kickbass.
if u make a 3db boost around 60-90hz u can improve kickbass too
try to respect this formula: f*gd<400
for this u will need to simulate that box (if u have t/s parameters)
group delays smaller then 10ms@50hz or 3-4ms@80hz are perfect and u will "hear" kickbass.
if u make a 3db boost around 60-90hz u can improve kickbass too
Hey all,
What about the passive radiatior on sale now by PE?
It is an 8"er for $10 smackers. Would it work for me if I seal the port? I guess I could get two and put one on each side of the box, that would look very cool to me.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-492&dotd=031506
What about the passive radiatior on sale now by PE?
It is an 8"er for $10 smackers. Would it work for me if I seal the port? I guess I could get two and put one on each side of the box, that would look very cool to me.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-492&dotd=031506
I think your Vb and tuning goal should work out, depending upon how high you want to cross it over. Keep in the EBS aligment lowers the efficiency a bit, and you may wish for more than 70W. The little port just isn't going to work, and you'd have to make a bunch of bends in a larger port. A slot port may work, but a PR is far easier.
For the same price as two of the 8" PR's, I'd strongly consider the 10" PR Cal linked to, or this:
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=55-2425&info=details
It was made for the MCM clone driver, has a displacment advantage, and matches cosmetically. I don't know if they PE drivers suspensions will handle enough extra mass to reach the tuning you desire.
I built a sub with the MCM driver, a 10" passive with a (supposed) 24mm Xmax (no longer available, AFAIK) and a 150W plate amp. There was no lack of output, and I think most of the PR's excursion capabilities were used.
Are you sure you don't have any leaks? Try playing a 20hz test tone (don't break it) and feel around for moving air.
For the same price as two of the 8" PR's, I'd strongly consider the 10" PR Cal linked to, or this:
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=55-2425&info=details
It was made for the MCM clone driver, has a displacment advantage, and matches cosmetically. I don't know if they PE drivers suspensions will handle enough extra mass to reach the tuning you desire.
I built a sub with the MCM driver, a 10" passive with a (supposed) 24mm Xmax (no longer available, AFAIK) and a 150W plate amp. There was no lack of output, and I think most of the PR's excursion capabilities were used.
Are you sure you don't have any leaks? Try playing a 20hz test tone (don't break it) and feel around for moving air.
Would a leak cause a significant lack of output like I had?
The sub is at home, unfortunately, and I'm at college. I don't have the tools here to do anything really so I left it at home. When I'm back I'll take out the foam, seal the port, test for leaks, and then add a radiator to the bottom of the box and I see that to be the best plan.
The sub is at home, unfortunately, and I'm at college. I don't have the tools here to do anything really so I left it at home. When I'm back I'll take out the foam, seal the port, test for leaks, and then add a radiator to the bottom of the box and I see that to be the best plan.
Before buying the 8's you should calculate how much mass you'd need to add and ask PE if they'll take it. I'd guess not. I've used this quick and dirty method before. I don't know how accurate it is. I'm sure a proper modeling program will be much better.
http://www.diysubwoofers.org/prd/
The MCM is great for the purpose, as it starts out at 400 grams.
The PR's suspensions probably can't handle the cone's weight in a downfiring setup.
http://www.diysubwoofers.org/prd/
The MCM is great for the purpose, as it starts out at 400 grams.
The PR's suspensions probably can't handle the cone's weight in a downfiring setup.
Yeah a PR is usually a modified driver. They take out the magnet and the coil, then they overweight the cone. Problem is usually the surround and the spider used are the same, so they are near their weight limit. If you do it downfiring, the cone will destroy the spider and the surround over time.
If you still want to go with two PRs, you could go with two 10".
Did you check the two 8"? Maybe they would work.
If you still want to go with two PRs, you could go with two 10".
Did you check the two 8"? Maybe they would work.
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