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Discussion Starter #1
Hi :wave:

I'm looking for some advice on what size enclosure and what tuning freq I should use with this driver. I can go as big as 10 cu ft and I'm looking to tune it quite low (below 20hz)

View attachment AA Hovoc 15 2011.wdr

If any of you could give me your opinion on what to go for I would appreciate it.

Cheers :thumb:
 

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It has an Fs of 29, which is relatively high.

You could do 20hz no problem... I'm not sure how much lower you'd want to go.

I can create some excursion graphs.. I don't know how many watts these drivers are rated for.

Images are 15, 18, 20 hz. The dip starts to grow dramatically with tunings below 20hz.
 

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Cheers for that Zeitgeist. I'm currently testing the driver with a EP4000 at 4ohms bridged in a 4.5 cuft box tuned to 35hz. If I stuff the port with a pillow I think it sounds quite nice, otherwise it's really peaky, which I expected with that tuning. With no hpf I can run 15hz sine waves until the amps clip light shows without the driver showing any signs of distress, so I'm really not worried about the excursion limits.

What would you recommend after looking at those graphs. 18hz tuning seems ok, although is the 2db loss around the 20hz range worth the 3db gain at 15hz in your opinion?
 

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Here are 3 winisd files for you.

10 cu ft 17hz tune with 1000 watts

10 cu ft 17hz tune with 1000 watts

10 cu ft 14hz tune with 1500 watts


Personally I think the 14hz tune is about as low as you would want to go. This would give you with room gain very good output down to 11-12hz. That's what I would shoot for.

cheers

Graham
 

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Discussion Starter #5
Thanks Graham! that 14hz tune does look good :)

Would you expect it to perform well on both movies and music with the 14hz tuning?
 

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The 14hz tune in the 10 cu ft box almost makes it a LLT sub for a 15" driver and when you look a the group delay on the lower tune it is quite a bit lower. You loose 2db at 20hz on the higher tune which is nothing really but you gain so much below 15hz which will come in handy for low bass tracks for having a play with.

I presume this is a dual 2 ohm driver so you could buy a EP4000 amp and bridge it into 4 ohms and away you go. And you wouldn't need a hpf too.


I'd say go for it.
 

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Discussion Starter #7
Yes, it's a dual 2 ohm driver and I already have a EP4000 :bigsmile:

Just one last question....I have always made slot / L ports. I'm guessing that wouldn't be possible with an enclosure this size would it...?
 

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Port - 3 x 9 inchs x 32 long. Does that sound ok? or do I need to make the port bigger and longer to avoid port noise?

 

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Just realised I wasn't keeping my eye on the ball and missed the port velocity speed.

Here's a revised winisd file.

10 cu ft tuned to 15hz with the following port.

12" wide by 3.5" high by 44.75" long.

1000 watts input power gives 33 m/s velocity

1500 watts input power gives 41 m/s velocity

The 1500 watts figure is quite high but my low tune has a velocity off 44 m/s at 10hz and I have never heard any port noise even at that speed. You max velocity is at 13.5hz which shouldn't cause any issues. Some people will say it way too high but I've never come across any problems.

The other option would be to go for a 16hz tune which with a hpf set you could have 2000 watts off input power and this would give a port off 10" wide by 4" high by 36.75" long.
Port velocity is 30 m/s and that is with 2000 watts input power which would suit the ep4000 better as that is what is rated at.
 

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Discussion Starter #10
Thanks alot for spending your time to do that for me :) I think I might go for the 16hz tune. I will re-read through it all in the morning and make a propper sketchup model.

Thanks again mate :T
 
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