Harbeth Monitor 40.1 specific

[chord]

A question regarding positioning.
Can the speakers be placed closed to the back wall and side wall? What is the minimum distance for each?

[A.S.]

I'd say that the minimum should be about 2 feet. You will encourage bass lift but that can sound OK depending on the music, your taste and how loud you play. 3 feet (say, 1m ) or more is ideal. I specifically worked on this region in the M40.1 design to make it more domestic room friendly than the studio-intended Monitor 40.

[chord]

Thanks for the response. If I have to position the speakers close to the walls, digital room correction should be able to correct the bass lift?

[A.S.]

The M40.1 design is now complete. As always, the last 10% of the design effort takes weeks of careful listening to brief snips (say, each track under 30 seconds) of the widest variety of music possible. I have copied my entire CD collection to a 'small form factor' Compaq PC with a very quiet fan which sits next to me in at listening chair. It allows me to call up thousands of music tracks at the click of the mouse - or at random.

The way I work is to give my full attention to the speaker under design and deliberately not to make A/B switchovers - and not to listen to any other speakers* - until 99.9% of the design process is complete. Only when I am fully convinced from the way I feel about the sound presentation (and the in-room response measures nicely) that the design is complete to my own satisfaction do I introduce another speaker, and make an instantaneous A/B comparison with my relay change-over box. That was the point I was at yesterday evening.

A/B switching the M40.1 to the M30 (I happened to have them to hand) gives exactly the same balance in the mid/top between these speakers which is remarkable considering how dissimilar their size and make-up. The M40.1 has more resolution, bass extension and overall transparency but the M30/M40.1 are so similar that they would make a great combination either in one surround-sound system or in a studio situation where projects pass from the M30 to the M40.1 and back again.

I am very pleased that 15 months of investment in the M40.1 design yields a speaker that is hugely seductive and so truly a Harbeth. You can have complete confidence that this latest Harbeth is the best - and is 100% to the Harbeth formulae. And all in our 30th year!

*It's best, when working on a new design, to confine ones listening to headphones or portable radios as it is essential not to become imprinted with the signature of another hifi speaker. The object of the exercise is not to re-clone an existing speaker but to try and get as close as possible to a speakerless-sound. For that you need an empty canvas.

[Pluto]

The M40.1 design is now complete.

Alan - congratulations on a landmark achievement. Let's now hope that you will be able to manufacture the many hundreds that your Far Eastern and Stateside customers will be begging for!

[A.S.]

Thank you for the kind words. I'm now zipping up the entire design archive and running off the master curves so that production can clone the Reference speaker.

I am not especially neurotic by nature but when you've worked towards this point incrementally for more than a year you really don't want hand over your baby and there is always the worry that you've overlooked something. So, I just couldn't resist one final day spent on design verification and auditioning with a wider range of speakers on an A/B comparison. From the start of the day to the end I was not tempted to play with even one component on the crossover. And then the final - perhaps ultimate test: instantaneous A/B switch-over comparison with the original M40. This was very interesting indeed as I have not critically listened to the M40 for over a year but this is what I found on an instantaneous switch over:

- The overall balance is very similar between the M40 and the M40.1 and if you leave the room and returned, you can not immediately say whether you are listening to the M40 or M40.1. As the Monitor 40 has a substantial reputation, this is an ideal and credible situation.

Closer listening reveals areas where the M40.1 has an advantage over the M40 in my typical domestic room:

- M40.1 has a tighter, dryer bass with greater extension, lower Q that works with the untreated typical domestic room's natural low frequency boost (As opposed to the studio's very dry bass) to give a very gentle bass response that integrates smoothly with the mid/top and doesn't draw attention to itself

- It is impossible to hear the individual drive units. The integration is so smooth that there is no hint of the sound stage being confined by the boxes laterally, vertically or in the (z) depth plane. The sound stage just hangs there in space.

- Having listened exclusively to the M40.1 as it's been under development, my metal construct of how a sound stage is painted by two speakers is based solely on how they behave - and that's my internal reference. What I have just realised right at the very end of this process now I'm making A/B comparisons is of the M40.1s astonishing stereo width and depth. It truly is a revelation.

- Believe it or not, the M40.1 is more open in the presence/lower treble which gives vocals exactly the right weight so that they are eerily realistic even panned centre stage. The vocals sound extra realistic because the chest component of the voice integrates very well with the lip component. Note: It is a mental illusion that allows sounds, such as vocals that are panned centre stage, to appear as central by some very complex processing in the brain. The more coherent cues that the loudspeaker can provided to the brain, the greater the holographic vividness of these images. I seem to have found and used those magic sonic cues in the M40.1's presentation.

We have started to build the crossovers and as soon as we have a stock of these, all checked against the master, we can commence production. Photo of the master reference board that I hand made attached.

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[A.S.]

Here is a pair of Eucalyptus M40.1 photographed in a traditional setting one with the grille on and one with the grille off. The stands are prototype filled-metal made by a local company to our CAD design.

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[P.C.]

Thanks Alan, This really is my dream speaker ( I have M30s at present) my only problem, apart from cost! is my listening room size which is only 15' x 13' x 8' .It does however open up from a 6' gap along one of the 13' side walls to another room a little larger than the listening room. Could this help in avoiding any excess bass that may occur? Thanks again Philip.

[A.S.]

... my listening room size which is only 15' x 13' x 8' .It does however open up from a 6' gap along one of the 13' side walls to another room a little larger than the listening room. Could this help in avoiding any excess bass that may occur?

The bass end of the M40 and M40.1 sonic spectrum has been the subject of the most intensive research by me, all carefully annotated so that I can be absolutely sure that the M40.1 will work in just about any room. Your room is about the size of my listening room and I truly believe that the M40.1 is not capable of excess bass: the bass is extended and tight.

As I mentioned elsewhere, concerning the design brief, it was the No.1 design specification that then new M40.1 must be 'user friendly' in normal domestic living rooms. As for use in professional studios, they have the time and money available for us to optimise the bass in any way they wish, but the domestic user should have a solution that works 'out of the carton' without EQ, DSP room correction or room treatment.

If I had the choice to make the bass extended and tight or dramatic and obvious I would select the former: and that's what you have in the M40.1.

[DSRANCE]

I am most impressed with the way you've allowed us "into" the development of this speaker to such a great extent. Many thanks indeed.

As a lover of "big" speakers I can only envy those lucky future owners of such a carefully designed monitor. I should be grateful though, if you could give a considered opinion regarding fancy capacitors in the crossover, as I can visualise, some years down the line, someone replacing all those carefully chosen, measured and matched "horrid" electrolytics with totally inappropriate (in this design context) expensive "flavour of the month" ones and totally altering, if not ruining, the performance of the crossover in the process (I've seen this done to otherwise fine, vintage Spendor BC1's for example)...

One final question please. Will there be an active version for domestic use? (excuse my ignorance if this is mentioned elsewhere).

[chord]

Could you please give an idea of when M40.1 will be available in HK?

[A.S.]

I was in Hong Kong a few days ago and discussing the delivery situation. We have a substantial back-order from Hong Kong. We are duplicating the PCBs now. Unfortunately, our production manager broke his arm just before I left the UK and it has not healed. As I write, he is in hospital having a metal plate fitted across the break. He is key to us starting production.

It is our intention that we make the first few pairs next week and that includes some stock for Hong Kong.

[A.S.]

Active M40.1. Situation is this:

A very gifted sound engineer (with a large broadcast organisation) has, at his own initiative and with just basic data from me, found a way to program a multi-channel off-the-shelf digital filter box to precisely clone the crossover of the passive M40.1. This dramatically cuts the development time of a marketable active M40.1 solution, just requiring the programed filter box plus six channels of amplification (bass, mid, tweeter x 2).

We discussed today making time between Christmas and my trip to CES2008 to get together and verify that the DSP works as we expect and to measure and listen to this low-cost active solution v. passive. If it does sound OK, then we will endorse his solution. Whether he is willing to make it available to all customers I can't say, but we are treating this project very seriously indeed.

[P.C.]

[QUOTE=A.S.]. Your room is about the size of my listening room and I truly believe that the M40.1 is not capable of excess bass: the bass is extended and tight.

Thanks Alan, thats great to know. Now starting to save up for a pair.

[A.S.]

You will not be disappointed. If you are, I will offer to eat them for you!

[eelekim]

Mr Shaw, if it really happened and you happened to be too full to eat, I'd volunteer to bring the great speaker home to enjoy the feast. :P

mike

[harbethpr]

Here are photographs of the Monitor 40.1, production model in various settings.

[Peter Jacobsen]

I love the fireplace behind the speakers!! Does anybody live there? The Queen?

[fwinston]

Greetings Alan,

Do you have the frequency response numbers for the M40.1? I"m curious to know how they (may) differ from the M40's 40Hz-20kHz +/- 3 dB.

Thank you.

Frank Winston

[A.S.]

Hello,

We don't publish frequency response curves, because there are so many variables in the measurements that comparisons are impossible. Each brand develops its own methodology and refines it until their measurements convey enough information to them, which somehow correlates with what they hear. Most of us use mathematically manipulated in-room frequency responses (various smoothing techniques) to arrive at a believable quasi-anechoic curve with mental allowances for the known features of the room, according to our long term experience. Unless you could differentiate the room from the measurement the curves would be useless.

What I can say in that in-room (which is what really matters) the M40.1 is, under my measurement conditions and even more importantly, to my ear, exceedingly neutral, balanced and exciting. There are no oddities in an otherwise commendably flat response, and certainly no 'BBC dip' which has never been a feature of Harbeth speakers and about which there is much misunderstanding.

You are correct: what measurements would reveal is that the overall mid/top measured response is very similar between M40 and M40.1 +/- 1dB or so but the M40.1 is measurably and subjectively dryer and tighter in the bass in my rather sparsely damped listening room. What you really need is an outside quasi-anechoic curve, but I'm sorry to say that it's too cold outside to take one. For that we need to get up to 20 degrees C or more or an expensive re-visit to the BBC anechoic chamber, which I do not myself need now I am completely happy with the design.