Enclosure

Calculate Enclosure Size

Look at golden ratio of enclosure

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Types

• Infinite Baffle
• Sealed or Closed Enclosure
• Vented or Ported Enclosure
• Passive Radiator Enclosure
• 4th order enclosure
• 6th order enclosure
• Transmission Line
• Horn Loudspeaker
• ABC

How to select enclosure type

First, you need to get Thiele-Small Parameters from speaker datasheet or measure by yourself.

Generally

• Bass reflex is +3dB louder than sealed.
• Bandpass has a narrower frequency response bandwidth, compared to bass reflex.

Hoffman’s Iron Law

Choose 2 of

• Enclosure size
• Efficiency
• Low-end extension (deep bass)

1. EBP (Efficiency Bandwidth Product)

$EBP=\frac{Fs}{Qes}$

EBP	Recommended
< 50	Sealed or 4th order
50 - 100	Either
100 - 130	Vented or 6th order
> 130	Horn Londspeaker

2. Qts

Qts	Recommended
< 0.4	Vented
0.4 – 0.7	Sealed
> 0.7	free-air or infinite baffle application
~ 0.7	Most compatible with Transmission Line

3. Isobaric drivers

Isobaric loading

• Put 2 speakers series to each other (magnet to cone) or facing each other (cone to cone)
• same $Fs$, same $Qts$
• but cut $Vas$ in half
• so smaller enclosure can be build