New generation Monitor 40 (M40.1 provisional name)
I have not been able to give my full attention to the User Group for several weeks. This is because of my commitment to the final stages of the design of the new Monitor 40. Now that I have virtually finished, I would like to take a short holiday. After I return, I will listen again and if I am completely satisfied, we can set a production start date for as early as possible.
This project has been underway for over a year and has ranged through every single aspect of the design. The original objective was quite narrow; to replace the abruptly discontinued VIFA bass unit with a Harbeth designed, Harbeth made woofer. However, as the months progressed, I became deeper and deeper involved with the minute details of the design, and this led to numerous small improvements. So the bass unit is completely new - a 12" first for Harbeth and the midrange driver is a new version featuring a 9 ohm voice coil to keep the system impedance nice and high: a very easy load indeed.
Unfortunately, the changes are so extensive that there is no practical upgrade path from the original model.
You may be interested in my reasoning behind the overall system balance of the new M40.1. I believe that in the 10 years since production commenced we have filled most of the professional installations that demand a true-BBC monitor. Also, most BBC installations are Active, and this allows great flexibility in tuning the speaker to the studio acoustics which is not possible with the passive version as used at home. This has resulted in some users deciding to invest in room-EQ systems when I would like to save them the cost, trouble and inconvenience by making the M40 even more universally usable in ordinary rooms.
The working life of a Harbeth is 15-20 years (or more) so the best potential for sales growth for the M40 is the domestic non-studio market; that is, ordinary rooms in your homes. With this in mind, I have decided that as the Active version offers whatever adjustments the pro user demands, I should concentrate on making the new M40 100% domestic friendly. That means, in the same size classic-BBC three-way box as the previous model ...
1. A tighter, dryer bass thanks to the cast-chassis plastic-coned Harbeth-designed and made 12" woofer (compared to the pressed chassis, paper coned VIFA unit)
2. Higher electrical resistance (and easier load)
3. Even smoother frequency response by attending to micro-details in the response,
4. Better on and above-axis response integration so less height critical due to complete redesign of the crossover (which uses less components)
5. New 8" RADIAL midrange driver with 9 ohm voice coil and long-throw high-flux magnet
6. Overall system is noticeably more sensitive. About 4dB more sensitive than the original model so nearly the same sensitivity as the C7ES3. That's an astonishing increase in efficiency.
Needless to say, it sounds 100% true to the Harbeth philosophy. What astonishes me is just how huge and unconstrained the sound stage is: as if the sound stage curves around the speakers and along the side walls. It must be related to the extremely well integrated responses.
We have many back orders to complete so please order soon if you expect delivery in 2007. More details to follow: look out for the August 07 News & Views newsletter with pictures of the (grey box, pro-cabinet) prototype being tested recently by Derek and myself in the BBC anechoic chamber. Normal domestic veneers are and remain Cherry and Eucalyptus. Picture of my prototype crossover - fewer components than the original model. I will try and make time to design a new PCB on my laptop.
Am I allowed a short holiday now - please?!
Alan A. Shaw
Harbeth Audio UK