NORTH READING ENGINEERING
NORTH READING, MASSACHUSETTS 01864 USA
 

SERVICES
  CUSTOM ENGINEERED PASSIVE LOUDSPEAKER CROSSOVER NETWORKS
  CROSSOVER NETWORK REBUILDS AND MODS INCLUDING DUPLICATION OF VINTAGE OR NLA DESIGNS
  ACTIVE FILTER DESIGN AND PROTOTYPING
  PC BOARD DESIGN AND PROTOTYPING
  VINTAGE McINTOSH AMPLIFIER RESTORATION AND MODIFICATION

Contact North Reading Engineering

WELCOME TO NORTH READING ENGINEERING

North Reading Engineering is a Massachusetts certified business founded to provide engineering services to those engaged in home and professional audio providing loudspeaker crossover network solutions, loudspeaker design, vintage amplifier restorations, amplifier modifications and measurement services. 

CUSTOM ENGINEERED LOUDSPEAKER CROSSOVER NETWORKS

Networks are designed and their performance verified using a wide range of tools including analog circuit simulators, high sampling rate acoustic analyzers, distortion analyzers and precision measurement microphones.  Acoustic measurements are taken in quasi-anechoic conditions using near and far-field techniques.  Designs can be implemented using custom wound autotransformers, PC board layouts and active filters.  

NETWORK REBUILDS, MODS, MEASUREMENTS
Do you have an old JBL, KLIPSCH, EV or other network that you would like made, updated, duplicated or measured?  Pricing is quite competitive and performance data demonstrating network behavior is provided to the customer.

VINTAGE McINTOSH AMPLIFIER REPAIR, RELIABILITY SERVICING, OVERHAULS AND RESTORATIONS
North Reading Engineering has the experience, tools and test instrumentation to properly assess the condition of your vintage, first gen solid state amplifier and make it a whole lot better. More information on amp servicing can be found HERE.

VINTAGE McINTOSH AMPLIFIER UPGRADES
Yes, the first generation McIntosh amps can be modified to make better sound.  A preamplifier section, designed as a direct swap for the 043-795 preamplifier board is available for the these amplifiers (shown below).  The preamplifier board provides a significant, measureable upgrade to these vintage classics.  More can be found HERE.

ACTIVE FILTERS
Crown Amplifier Modifications
D45-75A

With this active filter board the Crown D45-75A series of two channel amplifiers is transformed into the ideal, low cost midrange-tweeter amplifier or "bi-amplifier" for two-way systems.  More on this very cool modification is HERE
.

Crown XLi800, 1500, 2500 and 3500 Class AB
An active filter insert that converts the Crown XLi Series of low cost, high power Class AB amplifiers into steep slope, very low distortion, actively filtered bass horn amplifiers.  Filters specifically designed for the Klipschorn and Jubilee bass units are also available HERE
.

Crown XLi Series, Triamped, 2-Channel, Actively Filtered "Stacks"
If you want to go 3-way active using Class AB amplifiers there is now no need to spend a small fortune on amps, networks and cabling.  With the active filter inserts shown above a 3-way amplifier stack for the Klipschorn, Jubilee or any 3-way audio system can be had for very reasonable cost.  North Reading Engineering can design and install active, steep slope filters in an XLi stack to accommodate either a 2 or 3-way system.  Amps run cooler, no passive network losses and an independent volume control for each driver.

North Reading Engineering Pages
MODELING THE KLIPSCHORN BASS HORN (Part I) - The Beranek Model, LTSPICE and a slew of measurements.
PHOTOGALLERY OF A KLIPSCHORN REPLICA BUILD - Building a Klipschorn is not for the faint of heart!
A KLIPSCHORN NETWORK FOR BUILDERS - A measured design you can build yourself.

Places To Visit
VOLTI AUDIO
RETRO VINTAGE MODERN HIFI
KROHN-HITE
SOUNDSCAPES
NORTH READING ENGINEERING FACEBOOK PAGE



Website and contents property of North Reading Engineering, North Reading, MA 01864 USA.  No part of the above may be copied and published, in part or in total, without permission.
2017 John Warren