Final sub cabinets

[jeffsg4mac]

Picked up a table saw at Sears today and started my final sub cabinets. Right now I have them tuned flat to 20hz in a 25in cube and they are way too big. Just look at how huge these things are. I am glad I never finished the cabinets. The new ones will look just like the Axiom EP600, but slightly smaller at 45x15x15. Right now they are so big I can't even put one up front. Since my in room response was into the high teens I tuned them up just tad to 23hz for a little better power handling. The drivers are some ACI SV12's that I got from a friend who never used them. I will put up some in progress pics tomorrow.

 

[jeffsg4mac]

Here is the response graph.

 

[lsiberian]

interesting to say the least.

have you tried out winISD Pro yet?

It's the new fad and everybody's doing it.

Ok I envy your bass box pro 6

 

[jeffsg4mac]

interesting to say the least.

have you tried out winISD Pro yet?

It's the new fad and everybody's doing it.

Ok I envy your bass box pro 6

I tried it, but I am used to bass box pro. They gave me almost identical results as they should based on the same math and parameters.

Getting it together now, pics later tonight

 

[jeffsg4mac]

Hey guys some pics as promised. I just finished putting the radius on the edges and tomorrow I will putty and sand it down. Sunday I will shoot the first coat on and if looks good I will put another one on monday. If I am not happy with the the first coat then I will shoot some texture on and then apply another coat of satin black.

Enjoy!

 

[annunaki]

Jeff,

How much clearance is between the rear of the enclosure the the vent inside the enclosure?

It looks like it is a bit close from the picture. If it is not at least the port's diameter away from a boundary it may induce chuffing by increasing vent velocity around the opening.

I am surprised you did not go the route of a slot vent.

 

[jeffsg4mac]

Jeff,

How much clearance is between the rear of the enclosure the the vent inside the enclosure?

It looks like it is a bit close from the picture. If it is not at least the port's diameter away from a boundary it may induce chuffing by increasing vent velocity around the opening.

I am surprised you did not go the route of a slot vent.

I am going to stick an elbow on it. I was just checking the fit.

 

[annunaki]

I am going to stick an elbow on it. I was just checking the fit.

Be sure to radius those internal edges.

What was your vent velocity in m/s with rated input power in your modeling??

 

[jeffsg4mac]

Be sure to radius those internal edges.

What was your vent velocity in m/s with rated input power in your modeling??

Yep already done Vent velocity with rated power was 31.5 at 19hz. On the high side but below the 35 mark. I just was not liking the results of the slotted port.

 

[annunaki]

Yep already done Vent velocity with rated power was 31.5 at 19hz. On the high side but below the 35 mark. I just was not liking the results of the slotted port.

31.5 m/s is going to be VERY audible. 17m/s-18m/s is considered the high end of what is acceptable.

Sorry to say but this is going to choke out your low end output and add a lot of coloration to the low end.

 

[jeffsg4mac]

31.5 m/s is going to be VERY audible. 17m/s-18m/s is considered the high end of what is acceptable.

Sorry to say but this is going to choke out your low end output and add a lot of coloration to the low end.

I don't know about that. I was not audible on the other cabinets. I have pumped frequencies through them from 20-80 hz and heard nothing but clean low end and no distracting port noise. I was getting low end down to 16 hz in my room too. Remember too that was at 19 hz with 350watts and 112db's output. At the F3 point the vent velocity was considerably lower.

 

[annunaki]

I don't know about that. I was not audible on the other cabinets. I have pumped frequencies through them from 20-80 hz and heard nothing but clean low end and no distracting port noise. I was getting low end down to 16 hz in my room too. Remember too that was at 19 hz with 350watts and 112db's output. At the F3 point the vent velocity was considerably lower.

Assuming that it is 31.5ft/s and not 31.5m/s that would make sense. Port compression is setting in at 31.5m/s and does limit output to a degree.

 

[lsiberian]

I'd be mindful of chuffing too, but as long as your volume is reasonable I see no issues.

Still be careful.

 

[jeffsg4mac]

I don't think I will ever reach that point in normal real world use. Remember also I am building two of these guys. One goes up front laying down under the center channel and the other will be standing up in the back Before I build the second one though I will put the first one through some test to make sure I am happy with everything. If the weather holds then tuesday I should be testing!

Rob,

Where did you get the 31.5 m/s from? I have always understood that port noise starts when the vent is exceeding 10% of the velocity of sound in air which is approximately 35 m/s or 113 ft/s? Theoretically of course.

 

[lsiberian]

I don't think I will ever reach that point in normal real world use. Remember also I am building two of these guys. One goes up front laying down under the center channel and the other will be standing up in the back Before I build the second one though I will put the first one through some test to make sure I am happy with everything. If the weather holds then tuesday I should be testing!

Rob,

Where did you get the 31.5 m/s from? I have always understood that port noise starts when the vent is exceeding 10% of the velocity of sound in air which is approximately 35 m/s or 113 ft/s? Theoretically of course.

It's generally cleaner to have much lower port air velocity because it causes less distortion. Try breathing out a straw and you'll get the idea. a wider port = better breathing for the sub. Still many folks here are perfectionists. Though once you've tried wide ports I hear you never go back. It's like when you get a mean steak I guess. You never can eat bad steak again.

 

[jeffsg4mac]

It's generally cleaner to have much lower port air velocity because it causes less distortion. Try breathing out a straw and you'll get the idea. a wider port = better breathing for the sub. Still many folks here are perfectionists. Though once you've tried wide ports I hear you never go back. It's like when you get a mean steak I guess. You never can eat bad steak again.

Trust me I know. I have been building speakers for over 24 years. I have never had an issue with port noise on anything that I ever built myself, but I have seen and heard what happens when there is a problem.

 

[jeffsg4mac]

Ok here it is all puttied and sanded with first 150 then 220. It is now smooth as a baby's bottom and ready for first coat of primer as soon as I drill the mounting holes. Can't wait to try the new spray gun out Have to start another one next week Fun but it is a lot of work still.

 

[annunaki]

Rob,

Where did you get the 31.5 m/s from? I have always understood that port noise starts when the vent is exceeding 10% of the velocity of sound in air which is approximately 35 m/s or 113 ft/s? Theoretically of course.

I got the 31.5 from you.

I never exceed 17m/s-18m/s vent velocity. This helps to improve overall output at the extremes as there is no possibility of compression.

I have built systems in the past that had 30m/s vent velocity and you can hear the air moving at high output levels, no chuffing, but getting close.

 

[lsiberian]

Ok here it is all puttied and sanded with first 150 then 220. It is now smooth as a baby's bottom and ready for first coat of primer as soon as I drill the mounting holes. Can't wait to try the new spray gun out Have to start another one next week Fun but it is a lot of work still.

Is that your house and forest?

If so it's very pretty.

 

[jeffsg4mac]

Is that your house and forest?

If so it's very pretty.

Nope that is a day care center and appts accross from our hose.