TerryC
Stunt Coordinator
- Joined
- Oct 19, 1999
- Messages
- 218
Spent the day making a sealed Tempest and the results are much, much better than I expected for a sealed sub. No subjective comments yet as I've only finished it so there's only measurement data to find here.
Here is a Pic of the finished prototype sub:
Dimensions (H x W x D): 22 X 20.25 X 21.25
Volume after bracing/driver: 3.88ft3
Qtc: 0.75
Stuffed with 48oz's of Polyfill(not sure how much this effects Qtc?)
Here are some measurements taken at the seat as well as after EQ'ing:
Red-No EQ Seated low SPL
Pink-No EQ, Mic Placed 0.50" away from dustcap
Green-EQ'd, Mic Placed 0.50" away from dustcap. Attenuated 60hz area and boosted 20 to 40hz to make the sub almost flat nearfield
Blue-Seated position after the nearfield EQ'ing
One thing I hope some of the more experienced here can answer, how does EQ'ing change the Qtc of the sub if any at all??
Here is how it compares to my Ported Mass(4.18ft3, 19hz tune) at Max SPL:
Red-EQ'd Tempest
Pink-Non EQ'd Mass
Not much of a difference!! Very surprised at that myself as I'm sure others will be as well!
Here is a graph about having multiple subs placed within my room to see if I have any cancelation issues. Please note that no EQ used on this test as I do not have another RCA to Phono cable to allow me to have both channels running individually. Both channels are on their own but run off the same input vs, their own input. Will get that cable this week and EQ both subs for bass nirvana.
Subs are located in each of the rear corners on either side of the listening position.
Red-Tempest on its own(notice it is located in the better corner of the two)
Pink-Mass 2012 on its own
Blue-Paradigm Studio 100's on their own
Green-All three running together, notice the slight cancelation at 75hz, possibly something to be concerned for some but seems okay to me. If the volume gets turned up this cancelation becomes more noticeable, other frequencies get louder but the 75hz area stays where its at.
Last graph is the different phase settings.
Nothing was touched except the phase setting of the sub output on the Sony.
It pays to play with the phase setting which I've already learned long ago. I just put this up for others as an example of what improper phase can do. I get much better response from my rear subs in reverse phase.
That's it, will post some subjective stuff in the weeks to come. So far I really like the idea of a sealed sub EQ'd with lots of amp power. Seems to make a great combination. Comparing these results to the Velodyne FSR-15 I tested a while back it looks to me as if this sub will annihilate the FSR in about the same sized box. Maybe sometime in the next couple of months I'll be able to compare the two in the same room.
Terry
Here is a Pic of the finished prototype sub:
Dimensions (H x W x D): 22 X 20.25 X 21.25
Volume after bracing/driver: 3.88ft3
Qtc: 0.75
Stuffed with 48oz's of Polyfill(not sure how much this effects Qtc?)
Here are some measurements taken at the seat as well as after EQ'ing:
Red-No EQ Seated low SPL
Pink-No EQ, Mic Placed 0.50" away from dustcap
Green-EQ'd, Mic Placed 0.50" away from dustcap. Attenuated 60hz area and boosted 20 to 40hz to make the sub almost flat nearfield
Blue-Seated position after the nearfield EQ'ing
One thing I hope some of the more experienced here can answer, how does EQ'ing change the Qtc of the sub if any at all??
Here is how it compares to my Ported Mass(4.18ft3, 19hz tune) at Max SPL:
Red-EQ'd Tempest
Pink-Non EQ'd Mass
Not much of a difference!! Very surprised at that myself as I'm sure others will be as well!
Here is a graph about having multiple subs placed within my room to see if I have any cancelation issues. Please note that no EQ used on this test as I do not have another RCA to Phono cable to allow me to have both channels running individually. Both channels are on their own but run off the same input vs, their own input. Will get that cable this week and EQ both subs for bass nirvana.
Subs are located in each of the rear corners on either side of the listening position.
Red-Tempest on its own(notice it is located in the better corner of the two)
Pink-Mass 2012 on its own
Blue-Paradigm Studio 100's on their own
Green-All three running together, notice the slight cancelation at 75hz, possibly something to be concerned for some but seems okay to me. If the volume gets turned up this cancelation becomes more noticeable, other frequencies get louder but the 75hz area stays where its at.
Last graph is the different phase settings.
Nothing was touched except the phase setting of the sub output on the Sony.
It pays to play with the phase setting which I've already learned long ago. I just put this up for others as an example of what improper phase can do. I get much better response from my rear subs in reverse phase.
That's it, will post some subjective stuff in the weeks to come. So far I really like the idea of a sealed sub EQ'd with lots of amp power. Seems to make a great combination. Comparing these results to the Velodyne FSR-15 I tested a while back it looks to me as if this sub will annihilate the FSR in about the same sized box. Maybe sometime in the next couple of months I'll be able to compare the two in the same room.
Terry