Im getting some serious vibration from 70 to 80hz on my kappa perfect sub... whats up

[lsiberian]

I had a little bit of foam tape but not much. I need to go to the hardware store and get some.

Do you still have some left over rockwool?

You could cut it in a strip cloth wrap it and use that for the sub tape.

 

[Inertia]

I don't have any mineral wool left, i threw the rest out. I will get some foam tape.

 

[Haoleb]

You definetly need the foam gasket tape on the backside of the driver mounting lip. Not only to prevent any vibration but to get a good seal. It may be a ported cabinet but there are still internal pressure's

I found this stuff at ace and it fits perfectly, and works quite well.

 

[highfigh]

Not sure why it started happening now because it wasn't happening before but starting around 70 cycles to 80 cycles on my test tone cd my kappa perfect build is vibrating BADLY! Not sure why it wasn't happening before.... any ideas to fix the problem? I have mineral wool on the whole large brace panel.... just really weird why it wasn't happening before. I am confused.

What did you stuff the cabinet with, and is it a down-firing configuration? If it is down-firing, is the stuffing able to fall onto the back of the cone? How did you secure the brace?

Remove the woofer and use your fist to pound on the cabinet, listening for vibrations. Make sure it's not something nearby that's vibrating- I'm re-loading some speaker cabinets for a bar/restaurant and when I fired up the one I had all kinds of things making noise on my work bench.

If you have or will download Audacity (or something like it), it has a waveform generator and you can select the frequency to select it, instead of doing a sweep and finding a range. The thing to remember is that you don't want to do this at a high power level.

 

[lsiberian]

What did you stuff the cabinet with, and is it a down-firing configuration? If it is down-firing, is the stuffing able to fall onto the back of the cone? How did you secure the brace?

Remove the woofer and use your fist to pound on the cabinet, listening for vibrations. Make sure it's not something nearby that's vibrating- I'm re-loading some speaker cabinets for a bar/restaurant and when I fired up the one I had all kinds of things making noise on my work bench.

If you have or will download Audacity (or something like it), it has a waveform generator and you can select the frequency to select it, instead of doing a sweep and finding a range. The thing to remember is that you don't want to do this at a high power level.

he built a Kappa Perfect MidVQ Ported sub.

 

[MidnightSensi]

Remove the amplifier power, and gently apply pressure to the speaker cone, pushing it in and out... listen for rubbing/scraping... if a coil is unravelling you'll feel and hear the resistance.

I'm surprised those don't come with a seal gasket...

 

[highfigh]

he built a Kappa Perfect MidVQ Ported sub.

Do you have any diagrams or a link to the design?

What are the Fb and vent tuning frequency? Could it be that they coincide/are too close together or that there's too much amplitude below the Fs or Fv?

 

[MidnightSensi]

Do you have any diagrams or a link to the design?

What are the Fb and vent tuning frequency? Could it be that they coincide/are too close together or that there's too much amplitude below the Fs or Fv?

I'm fairly certain he built this:
http://forums.audioholics.com/forums/showthread.php?t=45528

 

[lsiberian]

You definetly need the foam gasket tape on the backside of the driver mounting lip. Not only to prevent any vibration but to get a good seal. It may be a ported cabinet but there are still internal pressure's

I found this stuff at ace and it fits perfectly, and works quite well.

Try this before you do anything else.

 

[Inertia]

Put the foam tape on and problem fixed! It must have just been vibrating the wood it was screwed onto. This thing kicks @ss... definitely gonna make another!

 

[lsiberian]

Put the foam tape on and problem fixed! It must have just been vibrating the wood it was screwed onto. This thing kicks @ss... definitely gonna make another!

Told you it was the screws

 

[JLMEMT]

Glad to see you got it fixed!

And that is one less than that I may do wrong when I finally get around to buidling them.

 

[Inertia]

Isiberian: thanks for the help its nice to have it sounding perfect now.

JLMEMT: You are gonna love this build... I have never heard a better sounding sub.

 

[lsiberian]

Isiberian: thanks for the help its nice to have it sounding perfect now.

JLMEMT: You are gonna love this build... I have never heard a better sounding sub.

There isn't a lot that will extend in a box that size that much.