E-170 Loudspeaker Enclosure

Yellowstone National Park, WY USA (Photo by Yuichi)

E-170 Specifications

= Volume : 170 liters
= Size : W 640mm, H 740mm, D520mm
= Type : Vented
= F(B) : Approx. 35Hz
= Direct radiator driver : TAD 1601x 15 in (or 38cm) or equivalent
= Frequency range : 35Hz to 1.2KHz (high limit is depends on driver
....capability

= Material : Cherry plywoods (25mm thickness)
= Front material : a Chinese quince laminated lumber (30mm thickness)
= Finish : Oil based clear polyurethane
= Coloring : Water based

= Others
- Speaker terminals : Right or left side
- Internal access : Rear baffle can be removed by loosing screws.

....Dec. 1990 MJ Magazine....
Building and assembly process

Cutting of the plates (25mm) except front baffle by a circular saw Cutting of front baffle
(30mm) plate by a circular
saw
Assembly process of walls
on the front baffle plate
Completion of basic box
assembly
Driver mounting hole
cutting process by a
electric router
Making of vent holes by
a router
Support structure between
front and rear plates
Surface finishing
All corner is rounded by
a router.
Rear side view for the
internal construction
Oil based clear coating
is applied twice after water
based coloring.
After applying sound
absorption material, driver
is mounted.

Measurement and Data


Left is a frequency response curve.

Data shows very flat output from 40Hz to 1000Hz. It isreally hard to obtain accurate low frequency datain regular listening room because of the effect of standing wave in a room. Also, we have to think about the effect of 1, 1/2, 1/4 space question.


Anyway, this is near fieldproperty. Therefore, loweredge output will increase in far-fieldlistening position, I suppose.
Right side data is a impedance curve.

As you can see, around 35Hz is anti-resonance point. There is no outstanding reflection in the enclosure. Therefore, I can remove a little bit of sound absorption material, rock wool in this case.

Since impedance in higher frequency goes up soundly, we can cancel these by impedance compensator
very easily.

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