KS-009

IMG_3520.JPG

Introduction
Prototypes
Enclosure
Crossover
Simulations
Measurements
Sound
Summary


Introduction

Technical specifications

General 3-way, dipole
Dimensions 330 x 1780 x 200 mm (W x H x D)
X/O frequencies 210 Hz and 2500 Hz
Drivers B&G Neo3-PDR
4 x Peerless HDS 5.25" Exclusive (831882)
4 x Peerless SLS-10" (830668)
Impedance 8 / 8 / 4 ohm


Prototypes

None.


Enclosure

Enclosure is not so heavy. Internal part of 30 mm MDF is very light.

Enclosure drawing: KS-009.pdf

IMG_3427.JPG IMG_3430.JPG
IMG_3428.JPG
IMG_3435.JPG IMG_3437.JPG IMG_3442.JPG IMG_3446.JPG IMG_3494.JPG IMG_3612.JPG IMG_3613.JPG

Crossover

LR2&4 (30.03.2008): KS-009LR2&4.xpc
Download Behringer DCX-Remote16a.exe to investigate xpc files.

Gain of power amplifiers:

Woofers 26 dB
Midrange 20 dB
Tweeter 20 dB

Connection of drivers

KS-009_wiring.gif

Simulations

Simulated vertical directivity. Drivers are monopolic - so this is not even close to real life:
KS-009_vert_off-axis_simu.gif

Frequency response wth LR2&4 crossover
KS-009_FR-simu_LR2&4.gif

Phase response with LR2&4 crossover
KS-009_PR-simu_LR2&4.gif

Step response with LR2&4 crossover
KS-009_SR-simu_LR2&4.gif


Measurements

Room response

Distance: 260 x 95 cm, 0°.
Adaptive (blue): filtered PIR + 600ms, smoothing 1/12 oct
Linear (red): 600ms, average smoothing 1/3 oct
Median (green): 600ms, median smoothing 1/3 oct
Average (black): average of previous three curves
KS-009_FR_260cm_000deg_R.png
Level of 300...800 Hz is too low compared to higher frequencies. Slightly too much mid-bass also.

Impedance response

SLS-10"

SLS-10_ZR.gif

HDS-5.25" Exclusive

HDS-150_ZR.gif

Neo3-PDR

Neo3-PDR_ZR.gif

Harmonic distortion

90 dB at 1 meter
KS-009_THD_90dB.PNG


Sound

Dynamics and slamming of higher frequencies is moderate. Bass slam is...  hmmm... dipolic.

Horizontal listening range is not exceptionally large. Upper midrange yodels to 90 degrees, restricting listening sector below 360 degrees. Listening is possible over longer distances and higher elevation. Longer distances increases presence. "They are here" illusion and naturality are ok, but there's not too much "flavor of life" in the reproduction.

Tracing of bass notes is good, but better exists. Bass is soft and tempo slow - like with lowered pitch. Bass extension is enough in our house.
Midrange is very good but slightly thin. Sound balance is not perfect - there could be more level at lower midrange from 300 Hz to 800 Hz to decrease thinnes and bring vocals in front of the band. This is adjustable with active X/O - of course.

Clarity and transparency of treble is not very good over longer distances. There was also some resonance at low treble. Measurement shows ageing symptoms at 6-7 kHz.

Soundstage is logical and exact but not needle-sharp. It's higher and deeper than with average box speaker. Sometimes high frequency voices disintegrate to the speakers. Especially classical is divided into speakers too much if listening triangle is close to equilateral. Etheric - floorless floating of vocals doesn't exist.


Summary

Speakers are ok even there were compromises everywhere. This project proved that it's possible to make a good dipole speaker without special intelligence, knowledge, luck, materials and working methods. Dipole is able to fix and hide many kind of shortages in design. Maybe this is the reason why open baffles are so popular.

Page updated 19.10.2010

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