I want to make a very simple sealed cabinet with a full range 5 inch speaker. I am using this to play back reference recordings as I practise piano and guitar, so as I am recording in mono, I only needs one speaker. I also didn’t want a tweeter as I only need it to go up to 12khz, and I want to avoid phasing.
This is the speaker:
http://www.farnell.com/datasheets/1783230.pdf
When I input the data into several calculators for sealed cabinets, it came back saying I needed a 81.28L cabinet. I must of done something wrong?
This is the speaker:
http://www.farnell.com/datasheets/1783230.pdf
When I input the data into several calculators for sealed cabinets, it came back saying I needed a 81.28L cabinet. I must of done something wrong?
The Vas is is 7.7 liters and the Qts is 1.08, so this is a speaker for open baffle or infinite (sealed) baffle. For infinite baffle I've read that 4 times Vas is appropriate (so 30.8 liters), with a continuum of box size down to the driver Vas (7.7 liters) gradually affecting the Q of the box, with Qbox being in this (30.8 liters) case 1.08 at four times driver Vas and increasing *some amount* as the box gets closer to the driver Vas (7.7 liters).
It may be some artifact of the software trying to lower the Q of the box lower than the Qts of the driver, which isn't possible with a sealed box, but afaik an aperiodic box can do that a little.
It may be some artifact of the software trying to lower the Q of the box lower than the Qts of the driver, which isn't possible with a sealed box, but afaik an aperiodic box can do that a little.
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I looked your driver up and it has a QTS of 1.08 which is pretty high. Usually
a driver with a QTS like this is intended to be used on an open baffle not a box.
And if you use it in a box it will call for a very large box so your calculation seems
reasonable. You might look at using a different driver.
a driver with a QTS like this is intended to be used on an open baffle not a box.
And if you use it in a box it will call for a very large box so your calculation seems
reasonable. You might look at using a different driver.
Yes, maybe that speaker was a bit strange.
This is the other speaker I was considering:
https://www.visaton.de/sites/default/files/dd_product/bg20_8.pdf
How many litres for a sealed cabinet would this need?
This is the other speaker I was considering:
https://www.visaton.de/sites/default/files/dd_product/bg20_8.pdf
How many litres for a sealed cabinet would this need?
Vb = 2.46 ft3 = 69.54 liters
f3 = 61.07 Hz
fb = 61.06 Hz
Q of the box .707
According to this..
Speaker Box Enclosure Designer / Calculator
f3 = 61.07 Hz
fb = 61.06 Hz
Q of the box .707
According to this..
Speaker Box Enclosure Designer / Calculator
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An IB will bring the system Q to 1.08, higher than optimal.
An OB can be used to help lower the Q, but a 5 is not really suited to OB use without a helper woofer.
Your best bet might be a box as large as you can live with, heavily volume damped with an aperiodic vent structure to help damp down the resultin gpeak before rolloff.
dave
When I used that calculator it stayed at .707q for whatever values I put into it. It doesn’t seem to automatically calculate the q. I am having difficulty finding a good way or calculator to calculate qtc.
My sim shows the same results for BG20, given it should have some volume fill, and sealed volume (once above a certain threshold) becomes non-critical, so 55-60 litres F10 in the mid30s.
I haven’t heard the Visaton but the similar SEAS FA22 is very good and fits a similar sealed box.
Drivers that work well in sealed boxes are kinda scarce, if you are fine with other boxes, look at the Mark Audio Alpair 10.3/A11ms. Available from KJF Audio in Kent. He will alos likely do a flat-pak if you need. Pluvia 7, and given the HF requirement A12pw would be candidates.
dave
I haven’t heard the Visaton but the similar SEAS FA22 is very good and fits a similar sealed box.
Drivers that work well in sealed boxes are kinda scarce, if you are fine with other boxes, look at the Mark Audio Alpair 10.3/A11ms. Available from KJF Audio in Kent. He will alos likely do a flat-pak if you need. Pluvia 7, and given the HF requirement A12pw would be candidates.
dave
You can change the system Q manually to whatever you want, it will change the box size. That's the way to do it with this calculator, something more sophisticated might be able to give you the numbers from either way but you can see what the Q is for whatever size box this way, you just have to try it a few times..
On this other speaker
https://www.visaton.de/sites/default/files/dd_product/bg20_8.pdf
I think the qtc is 0.96 - on page 2.
So with calculating I came up with 29.25L which seems fine?
https://www.visaton.de/sites/default/files/dd_product/bg20_8.pdf
I think the qtc is 0.96 - on page 2.
So with calculating I came up with 29.25L which seems fine?
That's the box they're suggesting...
(the Qtc refers to the Box Q and the Qts refers to the driver Q)
(the Qtc refers to the Box Q and the Qts refers to the driver Q)
Ok thanks I understand now.
If I want to add rockwool dampening, does this change how many litres the cabinet is functioning at?
If I want to add rockwool dampening, does this change how many litres the cabinet is functioning at?
The idea is that adding fill allows for a smaller box — with less time-smeared stuff coming back thru the cone.
Why i suggested a smaller box range than the unstuffed model
dave
Why i suggested a smaller box range than the unstuffed model
dave
So would it still be ok using the previously calculated box size of 30L with the stuffing, or would I have to recalculate?
Box size and possible vent tuning will affect only say 2 lowest octaves, around resonance frequency.
What is your goal regarding low frequency range and maximum sound pressure level? Will you place them near the wall or on stands? Does your amplifier have tone controls?
What is your goal regarding low frequency range and maximum sound pressure level? Will you place them near the wall or on stands? Does your amplifier have tone controls?