HiVi F5 5″ Midwoofer Thiele/Small

HiVi F5 Thiele/Small

I have been avoiding buying the HiVi F5 for many years. That stems from my disappointment with their 8″ M8a. When I measured the T/S with DATS, they were completely off. Hopefully, this F5 measurements will be closer.

Manufacturer’s Specs
HiVi F5 Thiele & Small Parameters (DATS)
As it turned out, my fears were unwarranted. My F5 T/S by DATS is close to the published specs. Qts is 0.407 which is almost HiVi’s 0.41.

Sealed Box=4 liters | F3=115Hz | Q=0.70

The optimal loading in a Sealed Box is 4 liters. This is great as I intend to use the F5 as a midrange. In a 3-way speaker, I can build a 4 liter sub-enclosure inside speaker box. However, if the F5 is to be used with a tweeter in a stand-alone mid/high unit as in the Swallow-BC, a larger box is preferred.

Sealed Box=7 liters | F3=118Hz | Q=0.60

Using the same 7 liters sealed box as the Swallow-BC, the Qtc is 0.60. F3 is 118Hz. An active crossover at about 200Hz (24dB/oct) can then cross to the woofer for the bass.

Ported Box=7 liters | Fb=72Hz | Q=0.60

In a 7 liters bass reflex, the F3 is lower at 70Hz. Bear in mind that the Xmax of the F5 is only 2.5mm. Playing too loud can destroy the voice coil

Ported Box=13 liters | Fb=60Hz | Q=0.52

For an even lower F3, the F5 can be loaded into a 13 liters bass reflex. F3 is now 55Hz. Great for Back Ground Music.