Subwoofer riser

brunogiovs

Member
2014-09-29 7:16 pm
Hello guys

I have a 3 way active setup , so the low frequencies goes to a speaker cabinet of MDF 3.0 cu. ft. with a dayton Dayton Audio RSS390HF-4 15".

It will live in my basement, so over a carpet with concrete floor underneath. so I was wondering if I should put a raiser , this cabinet will be serving from 40hz to 300hz .

So if a raiser is needed what height is recommended?

Thanks
 
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Face

Member
2007-05-23 8:38 pm
I would not want 300hz coming from a riser. Remember, crossover slopes are not brick wall filters, so you'll have dialogue coming from below your feet. Same goes for bass shakers, I cross mine at 40hz otherwise the couch starts to speak.
 
300 is very high for a subwoofer like that, it means with a 3db slope your subwoofer will be producing audible frequencies up to the 500hz range and higher.

You can experiment and do what sounds good, generally most cross over 100hz or lower, so long your subwoofer is in the front sound stage there would be no need to raise the subwoofer at all.


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brunogiovs

Member
2014-09-29 7:16 pm
Sorry guys if wasn't very clear.
I have active crossover. it uses 48db slopes. no issue there.
I just want to raise the height of the all speaker as the mid and the tweeter is too low right now at the subwoofer cabinet has 20 inches and the mid has 9 inches.

So my question is how tall should be the raiser? should the mid ( 300hz to 2hk) be at level of sight ( when you are in sit position )?

Thanks
 

eriksquires

Member
2013-05-10 4:11 pm
You should try to achieve 2 things simultaneously.

1 - Avoid large surface areas making contact with another large surface area.
2 - Fix the speaker in place. The energy drivers exert to move air is tremendous. Newton's third law of motion applies here. To move forward, a driver must exert force on the cabinet in the opposite direction. This could cause the cabinet to move back and forth, creating minute doppler shifts in the final output, or even causing the speaker baffle to radiate out of phase with the driver. Straps or weight work. Experiment yourself to see if it's an issue. Add 20-40 lbs and listen. No improvement = no issue.

Of course, if bass matters to you, I always recommend at least a pair of GIK Acoustics Soffit Traps. Two pairs are even better. If you DIY them, make sure you have a design proven to work below 100 Hz.

Best,


Erik
 
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brunogiovs

Member
2014-09-29 7:16 pm
You should try to achieve 2 things simultaneously.

1 - Avoid large surface areas making contact with another large surface area.
2 - Fix the speaker in place. The energy drivers exert to move air is tremendous. Newton's third law of motion applies here. To move forward, a driver must exert force on the cabinet in the opposite direction. This can cause the cabinet to move back and forth, creating minute doppler shifts in the final output. Straps or weight work. Experiment yourself to see if it's an issue. Ad 20-40 lbs and listen. No improvement = no issue.

Best,


Erik

My speaker doesn't move a bit... just the subwoofer box weights 82lb.