Author Topic: Speaker cabinet damping (Kairos kit)  (Read 299 times)

Offline Ita0101

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Speaker cabinet damping (Kairos kit)
« on: July 17, 2018, 11:59:11 PM »
Hi,
I'm about to pull the trigger on Jeff Bagby, Kairos bare bones kit.
The full kit comes with Dacron damping.
I want to combine Dacron + Sonic Barrier 1" (from PE), Or Eco-Core damping from Meniscus.
What do you think?
Thanks,
Itamar.
« Last Edit: July 18, 2018, 12:45:21 AM by Ita0101 »

Offline rollo

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Re: Speaker cabinet damping (Kairos kit)
« Reply #1 on: July 18, 2018, 07:39:24 AM »
  The cabinet may have to be larger using the 1" th. Sonic Barrier. No-Rez is also a well regarded dampening solution. Have fun.



charles
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Offline Ita0101

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Re: Speaker cabinet damping (Kairos kit)
« Reply #2 on: July 18, 2018, 07:54:56 AM »
Are you sure?
If I will use 3/4" I still be needed?

Thanks
« Last Edit: July 18, 2018, 08:02:05 AM by Ita0101 »

Offline richidoo

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Re: Speaker cabinet damping (Kairos kit)
« Reply #3 on: July 18, 2018, 08:45:40 AM »
Stick with the stock stuffing. It's optimal for the design. I've tried many other stuffing schemes, now I'm back to stuffing that is very similar to stock.

Offline S Clark

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Re: Speaker cabinet damping (Kairos kit)
« Reply #4 on: July 18, 2018, 09:17:52 AM »
No, don't increase the cabinet size.  Although it seems backward, adding acoustic insulation increases the effective volume of the cabinet.  No Rez is better, easier, but more expensive than the other options listed.  However, it is self adhesive, so no need to buy any glues. Also, you don't have to smear glue on the inside of the cabinet.
Forget the measurements, are your toes tapping???

Offline Ita0101

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Re: Speaker cabinet damping (Kairos kit)
« Reply #5 on: July 19, 2018, 07:44:46 AM »
I will stick to original plans.
Thanks.


Offline richidoo

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Re: Speaker cabinet damping (Kairos kit)
« Reply #6 on: July 19, 2018, 09:23:40 AM »
The eco core from Meniscus is recycled demin cotton batt. It is extremely powerful acoustic absorber, makes excellent bass traps. I have 12 pieces of 2 foot x 8 foot x 4" that I roll up inside garbage bags. I have 1" thick sheets of it also. Whenever I put it inside a speaker it damps the drivers too strongly and sucks out the life and midrange detail. 

On the other hand, you want a lot of stuffing inside a box to minimize the internal reflections. This is why the polyfill is the right choice. It fills half the box as specified but does not overly damp the woofer, because it's a relatively lousy absorber. Air does not feel friction when passing through polyfill as much as it does with cotton or fiberglass insulation. A thin layer of cotton batt on the walls should work even better than polyfill for reflections, and have less driver damping than the 1" cotton. I have some 1/2" stuff sold online by Homedepot that I will be trying if I ever build new speakers.

Offline Ita0101

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Re: Speaker cabinet damping (Kairos kit)
« Reply #7 on: July 19, 2018, 02:57:42 PM »
Thanks for your answer.
I want to build sealed box, How did you build yours?
« Last Edit: July 19, 2018, 03:01:06 PM by Ita0101 »

Offline richidoo

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Re: Speaker cabinet damping (Kairos kit)
« Reply #8 on: July 19, 2018, 04:35:27 PM »
Thanks for your answer.
I want to build sealed box, How did you build yours?

I first built it sealed, on Bagby's recommendation. But later I changed to ported and I like that better because my room is too big for the Kairos. If you want to use Kairos with subwoofers then it has to be sealed to achieve good integration. But you can build it with ports and later stuff a sock in the port for the subwoofer.

If you have a small listening room, then sealed might work well. I have a huge listening room, so the sealed alignment was not able to fill up my room with enough bass. A small room has 2nd order room gain would match the 2nd order rolloff of the sealed speaker, making flat FR down very low. The trick is matching the corner frequencies of the room and the speaker to get flat response. The variables are the volume of the room vs the diameter of the bass driver. For 6" driver like Kairos the room has to be pretty small, like a bedroom, to make the sealed alignment make a flat FR in room. ymmv. In this type of setup, sealed will sound better, more natural. But I could argue a large room will always sound better even without enough bass. But not everybody has a big room. yadayadayada

Offline Ita0101

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Re: Speaker cabinet damping (Kairos kit)
« Reply #9 on: July 20, 2018, 03:48:33 AM »
I have small room and a SVS SB2000, I think to go for the sealed with out any port.

Thanks

:cheers:

Offline richidoo

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Re: Speaker cabinet damping (Kairos kit)
« Reply #10 on: July 20, 2018, 04:54:31 AM »
Cool!!   :thumb: