Betsy-K in a BR

[Karl71]

Has anyone tried the Betsy-K in a bass reflex enclosure?

I have modeled one in BassBox Pro and get a response hump peak at around 45Hz. It's about +3dB. How could I flatten it? That's the final result with heavy stuffing simulated. The F3 is 35.94Hz.

So that the enclosure will take up the minimum amount of floor space, a real premium in my living room, the box is about 48" H x 12" W. Could I be dealing with pipe resonances?

Any thoughts?

Regards,

Karl

[norman bates]

what exactly is wrong with a +3db bump at 45hz ?

sounds like the box is a bit too small.

Norman

[fastbike1]

Bassbox Pro doesn't know anything about pipe resonance.

You're tuned too low. Where is your box tuned? Based on measured T/s BetsyK seems to give the flattest response tuned to about 45 - 46 Hz. (65 -85 liters net)

[pjanda1]

Karl,

I bet your box is just a little small. The SimpleTL is my attempt to get the most out of floor space, so you might give it a look.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[Karl71]

Paul -

What about the Skinny Quasi TQWT/TL? Do you have plans available?

Regards,

Karl

[pjanda1]

Are we talking about the same thing? This thread is as close as I've got to plans.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[Karl71]

In the sticky for enclosures, you mention a skinny quasi tqwt/tl. I believe that you refer to it being similar to the Zu speaker cabinet. Is this the same as the box in the plans you linked?

[pjanda1]

Yup, that's it. It's similar to the Druid in profile, not in design! This too, will have a little "hump", but I tried to make it broad. The idea is to help out baffle step loss a bit. But, they should still be close to a wall, IMO. How does that cabinet volume compare to what you are simulating? You should be able to get similar results with a traditional round port. I think this is more fun, though.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[Karl71]

The dims are very similar. The vent is 4 in. dia. by ~1.5 in. length.

What do you think of a br?

[GM]

Originally Posted by Karl71

I have modeled one in BassBox Pro and get a response hump peak at around 45Hz. It's about +3dB.

Hmm, based on my understanding of what the reflex inventor/patent holder considered an optimum box loading, then using the published specs requires a ~2.03 ft^3 net/50 Hz Fb alignment when driven with a low output impedance and tuned to Fs with a high one.

Simming a golden ratio BR for a low output impedance in MJK's early freeware with both the published and measured specs from an earlier thread, shows only a 'full' sounding half space mid-bass response with only minimal damping and a lower F3 for the measured specs.

In a high enough aspect ratio alignment, proper driver and vent location will be required to preserve the inventor's theoretically correct driver loading.

GM