Quote Originally Posted by Ian Mackenzie View Post
Hi All,

I thought l would let you know where this is at.

With the flux of time during Covid 19 there has been some pondering of matching needs to product features and benefits.

With that in mind l am interested in your impressions and thoughts on the following:

Option 1.
A simple to use stereo 2 way universal analogue active crossover with continuously adjustable crossover points from 200-1500 hertz or similar.

24 dB LR slopes, state variable with balanced/unbalanced inputs and outputs.
Designed with premium TI audiophile chips and hi quality Wima capacitors and high quality pots.

This will be an improved Ashly or other universal crossovers like the Rane.

The idea is too keep it simple for those who want premium sound quality but aren’t into taking the lid off and making fine adjustments.

It won’t cost an arm and a leg because you will deal direct with the factory.

Option 2.
A stereo 2 way analogue active crossover that can be set up for specific Jbl systems using plug in cards.
In concept like the DX1. It will also feature a sub out put with an optimal low pass filter.

The crossover frequency, slopes ect are all set precisely for your particular Jbl systems.

The design will use premium class A Jfet buffers and high headroom studio quality discrete op amps.
Available in unbalanced as this crossover is for consumer hifi fanatics. Balanced connection and circuits add cost and complexity and frankly don’t promise improvement in sound quality.
All parts are of the highest quality. This product will be endorsed by Greg Timbers.

Option 3.

A Stereo 2 way or Tri amp analogue active crossover for the audio amateurs who enjoy building project loudspeakers of their own design.

The design will feature premium class A buffers like option two but with adjustable plug in crossover cards for crossover points and slopes. Special purpose plug in cards will be made available for equalisation of low and high frequency drivers and phase alignment of low and mid frequency drivers.

It will available with unbalanced or balanced connectors to a customers requirements.

Option 3 will be sold with the Dayton Omni Loudspeaker measurement system.

I have a reasonable inventory of popular JBL small and large format compression drivers and a growing collection of horns and woofers. So I can offer users with ball park crossover set up guidance.

Why Analogue? Because it’s simple with not a lot to learn and adjust. The focus is on doing the least damage to your precious analogue source. Vinyl is well and truly back and it sounds incredible with with a pristine signal path.

I have some state of art test abs measurement equipment on order.

Just a show of hands would be useful or other ideas.

Ian
Option 2 fleshed out for now.

Basic description
A stereo two way crossover with preset plug in crossover cards with D connectors and front panel level controls.

The user
The product is primarily for users of premium consumer JBL and sort after JBL vintage loudspeakers and other loudspeakers configured for bi amp operation. Audio amateurs will find application with the design of their own project loudspeaker system.

Cards will also be available for other consumer loudspeaker of popularity that have bi amp capability. Adjustable plug in cards will be made available including adjustable crossover frequency and crossover slopes.

Specification - draft
The front panel will have adjustment for both Low and High Levels for left and right loudspeakers, a power indicator.
The level tim controls will have a range of +6 db to - 20 db.
24 VDC power input jack from an external smps.
The outputs and inputs for Left and Right Low and High channels outputs and a left, right and mixed mono sub output for external self powered subwoofers. A rear panel D link connector is specified. This will simplify fabrication and aid user setup and installation.

The interior has plug in crossover cards which are installed by the factory on a main mother board.
The plug-in crossover cards can be installed or changed by the user with a removable top panel.
The std specification is up to 24 db LR but higher order filters can be achieved.
The mother board will have capacity for additional plug-in card modules to expansion capability to a fully active two way loudspeaker system.
This modules include LF Shelf to compensate for room boundaries, LF Boost, Room EQ Notch, LF phase shift (delay), Horn EQ with trim adjustment.
The motherboard can be configured for mono three way operation (4 way with sub output)

The interior has low voltage DC power supply.
Internal are some adjustments to assist with earthing to minimise earth loops
The product is packaged with a simple set up tool and a more advanced set up option available as an add on sale.
The chassis is made of machined and anodised aluminium panels and is solidly constructed.
Dimensions 18" x 4" x 15"
Weight 15 Ibs.

Specification and design
Low Noise Linear System Jfets, Sparko Labs and Sonic Imagery discrete studio grade operational amplifier modules.
Bourins and TDK potentiometers
Wima polyropolyne capacitors
Vishay resisters

Noise - 100 db
Distortion less than 0.002%
Frequency response 20 - 20,000 hertz +-0.25 db

Price POA based on a users requirements which will be unique in many cases. So you only buy what you need and can update and expand later.