Sir.Byrd
Lunatic Member
Is Fb the tuning frequency? They are tuned for around 35Hz IIRC, it wasn't exact due to the flared ports.
Sir.Byrd's 2226H based super speaker project
- Thread starter Sir.Byrd
- Start date
Is Fb the tuning frequency? They are tuned for around 35Hz IIRC, it wasn't exact due to the flared ports.
Yes Fb is the box resonance with the port and it is the minimum in the input impedance. Did you verify the tuning by measuring?
Looked like you had them pretty well stuffed in some of the photos. You might try reducing the stuffing, cut it in half in one and then compare the two - but I can understand not wanting to dig back into them.
Looked like you had them pretty well stuffed in some of the photos. You might try reducing the stuffing, cut it in half in one and then compare the two - but I can understand not wanting to dig back into them.
Very nice work, by the way!
Yes, the box losses at Fb go up when there is too much stuffing.
I perfer to use more than the old traditional standard of ~1" on
the walls or none, and I often go overboard then have to take
some out.
More is good for reducing upper bass cavity resonances, it also
makes the box appear bigger, volume wise which will give you
more bass around Fb, however this can be offset more by the
increase in losses if there is too much, or it is placed close to
the open end of the ports.
You might even try one with no stuffing just to get a baseline,
expect to observe excessive cavity resonances, but at least you
will hear what a low loss box sounds like as far as deep bass goes.
It is probably safe to put 1-2" on all the walls. Even more against
the back wall since it is far away from the driver and the open end
of the ports. You might go to 3 - 6" there.
You can confirm the tuning frequency by measuring the input
impedance. You don't have to do a precise measurement just find
the minimum between the two low bass peaks. Computer with
sound generator software, low power amp, series resistor and
AC voltmeter is all you need.
Yes, the box losses at Fb go up when there is too much stuffing.
I perfer to use more than the old traditional standard of ~1" on
the walls or none, and I often go overboard then have to take
some out.
More is good for reducing upper bass cavity resonances, it also
makes the box appear bigger, volume wise which will give you
more bass around Fb, however this can be offset more by the
increase in losses if there is too much, or it is placed close to
the open end of the ports.
You might even try one with no stuffing just to get a baseline,
expect to observe excessive cavity resonances, but at least you
will hear what a low loss box sounds like as far as deep bass goes.
It is probably safe to put 1-2" on all the walls. Even more against
the back wall since it is far away from the driver and the open end
of the ports. You might go to 3 - 6" there.
You can confirm the tuning frequency by measuring the input
impedance. You don't have to do a precise measurement just find
the minimum between the two low bass peaks. Computer with
sound generator software, low power amp, series resistor and
AC voltmeter is all you need.
Last edited:
Sir.Byrd
Lunatic Member
Actually it is the 4Pi schematic