Multiple Chamber Aligned in Parallel Cavity Resonator (MCAP-CR)
Suggested Cabinet Designs

Important Notes

Some reference design and drawings are listed here.
All the drawings below are based on author's calculation and design experience but not tested by author unless noted diferently.

Some of these are designed per request by certain readers. Most of designed cabinets are for more general use than for specific drivers. Suggested drivers are listed as well.
You may use this design or change design by yourself, if you agree to the condition that all the risk is taken care by youreslf. So you must not complain about design or drawing errors or sound if you do not like the sound of your works using these designs. This applies to all the coontents of my pages. User's satisfaction is not guaranteed.

Availability of standard wood material depends on business area.
  1. It is assumed that standard thickness of plywood is 12mm, 15mm, 18mm, 21mm.
  2. It is assumed that standard thickness of bonded pine wood is 12mm, 14mm, 18mm, 24mm.
Your information of available wood materials in your area is very much appreciated.

I wish you good luck with this information.

120 - 130mm (4.5" - 5")
160mm (6.5")
200 - 225mm (8" - 9")

Common Notes & Tips

Please refer to Application Reports of manufactured examples as well.

TR120b1 (design not yet complete)
TR120b2 (drawings checked by author: 2009/04/25)

Designed Characteristic Frequencies
30Hz, 40Hz, 53Hz, 66Hz, 74Hz, 99Hz

External Dimension
b1: 900H x 230W x 230D per channel
b2: 900H x 236W x 244D per channel

Assembly Drawings
b1/b2: Isometric Assembly
b1: Third Angle Projecion Drawing
b1: Plate Cutting Plan
b2: Third Angle Projection Drawing
b2: Plate Cutting Plan

TR225a1 (design not yet complete)
TR225a2 (design was checked by author: 2009/05/06)

Designed Characteristic Frequencies

External Dimension
1200H x 400W x 400D (192L or 6.83 cft per channel without double side panels)
Assembly Drawing
TR225a1 Isometric Assembly
TR225a1 Third Angle Projection Drawing
TR225a1 Plate Cutting Plan - not

TR225a2 Isometric Assembly
TR225a2 Third Angle Projection Drawing
TR225a2 Plate Cutting Plan 1 of 2
TR225a2 Plate Cutting Plan 2 of 2

(design checked by author: 2009/05/09)

This is modified version of TR130c1. TR130c1 has complex structure and even myself made mistake in one channel (it was modified as version c2). Version c3 was designed not to make assembly mistakes. Basic design is same as TR130c1.

Suggested Drivers
Any Feastrex 5" drivers especially D5e
FE138ES-R by Fostex
W5-1611SA by Tangband
Other powerful 5" drivers
6.5" fullrange drivers may be suitable

Assembly Drawings
Isometric Assembly
Third Angle Projection Drawing
Cutting Plan

DU130a (design checked by author: 2009/05/10)


This design is for non-classical music.  Lowest characteristic frequency was designed to 42Hz. Other characteristic frequencies are 58Hz, 82Hz, and 104Hz.
Lowest frequency of 42Hz will suffice for most music sources except particular classical musics. This is easy to assemble and economical.

Suggested Drivers
Mild 5" drivers are suggested.
L5 by Omnes Audio or HX132 by Ciare may be good to use with DU130a. TR130c3 is recommended for powerful drivers. Mild 4" drivers like FE103E by Fostex may fit.

Assembly Drawings
Isometric Assembly Drawing
Third Angle Projection Drawing
Cutting Plan

Common Notes and Tips

Selection of Woods
My design assumes that structure is rigid enough. It means that vibration of cabinet is not taken account. From this respect, wood may be selected in any way, unless material is not rigid enough.
I do not recommend very soft and/or light materials for structural materials. I prefer relatively heavy (density is bigger than 0.5 kg/L) materials.
Another important thing is availability and price. There are reasonably priced plywoods and bonded woods. MDF is also available, but it does not look good. Practically best material is linden-apiton plywood. It is relatively heavy and proce is reasonable. Another choice will be birch plywood. Birch plywood is more expensive than linden-apiton, but heavier.
Bonded pine wood looks better than plywoods. Disadvantage of bonded pine is its softness and its dimensional change. Even though pine wood was cut accurately, it changes dimension to 0.x %. This change makes difficult to assemble.
One advantage of DIY is to save money. We may choose best cost / performance materials with best drivers to realize best cost / performance.

Absorption Materials
Absorption materials should be chosen by users. Function of absorption materials is mainly abosorb mid-range and higher range sound pressure inside the chamber. Low-range sound pressure will not be much affected unless ducts are plugged. Plugging any duct is not recommended, because MCAP-CR is designed to maximize characteric vibrations of masses in ducts.
 I suggest not to use too much absorption materials, because it makes the sound dead. Using absorption materials must be based on user's preference.

Suggested Usage of Absorption Materials:
Important Notes:

Speaker Wiring Terminals
Setting terminals should be taken care by users.
Some terminals may release sound pressure from its gap or gap between terminal and cabinet. Recommended terminals are:
Large and thin plastic terminals are not recommended.

Choosing Wires
Expensive wires are not recommended. Cables really affect sound quality, but effect is very small compared with other reasons like driver selection or cabinet design & manufacturing. 0.75 - 1.25 square milimeter copper wire for power handling use may suffice.
You may try very expensive audio wires. It is up to you.