North Creek Music Systems

North 13W-06S

5" woofer has been designed for AV systems, MTM's and line arrays.

 

Features:

Pressed Paper cone

Inverted Rubber suround

Nylon Dust Cap

Cast aluminium frame

Vented Below Dust Cap

Magnetically shielded motor

High DCR

Special Price $14 each, $144.00/matched 12

 

Design Details

We selected a pressed paper cone as is very light and exhibits a nice midrange quality. Paper is warmer and more forgiving than other cone materials, and as we the intended crossover frequency is below 2kHz, there is no need to go to more exotic materials to extend the driver's bandwidth. The light cone allowed us to make a smaller magnet in the motor, that could be fully shielded with the addition of a bucking magnet and shield cup.

The nylon dust cap is a good match as it good and clean to 2kHz and rolls off nicely above.

The DCR of the driver is very high (7.18 Ohms) so it can be used in the MTM configuration without creating a difficult load for the amplifier.

The motor uses a 25mm voice coil 12mm in height. The top plate is 6mm thick and the pole is extended 1 mm to extend the symmetric magnetic field in the gap. This geometry yields a very linear 6mm p-p excursion, optimum for small acoustic suspension or aperiodic enclosures.

The frame is heavily ribbed cast aluminum with a 4-bolt mounting pattern.

Theile-Small parameters are as follows:

Fs = 76.5 Hz

Qts = 0.743

Qes = 0.849

Qms = 5.92

Vas = 5.19 liters

Re = 7.18 Ohms

Bl = 5.93 Tm

d = 13.0 CM

Sd = 86.6cm2

SPL = 86.2dB/2.83V,1m

recommended cabinet volume 5 to 7 liters, sealed or aperiodic.

At right is an MTM tower prototype system built by Lee Taylor.

 

 

The North 13W-06S19W exhibits a remarkably smooth frequency response of +-2dB from the box tuning requency to nearly 2kHz. A second order crossover at 1.8kHz is recommended.

 

 

Below is the free air impedance curve. DCR is very high so several may be used in parallel or series-parallel combinations without straining the amplifier.

 

 

North 13W-06S .....$14.00 each, $144-matched 12

 

Our first loudspeaker offered with the North 13W-06S is in combination with the North D25-06S called "Echo". It is a near wall specific, subwoofer required, 5.1 to 7.1 channel and surround loudspeaker, just a touch smaller than the Okara II. System frequency response is shown below:

This crossover network is decidedly simple; a first order with impedance compensation, where the compensation resistor is deliberately very low so the slope behaves like a second order around turnover. This combined with the 13W's natural frequency response makes a very easy third order low pass to work with.

The tweeter network is a standard second order followed by an attenuation L-pad.

Component values are

L1

2.2.0mH

C1

20uF

R1

2.74 Ohm

C2

8uF

L2

0.56mH

R2

3.32 Ohm

R3

6.19 Ohm

 

 

The Echo is available unassembled for $149 per pair.