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INTRODUCTION - PLEASE READ FIRST TO UNDERSTAND THIS FORUM!

"This Harbeth User Group (HUG) is the Manufacturer's own managed forum dedicated to natural sound from microphone to ear, achievable by recognising and controlling the numerous confounding variables that exist along the audio chain. The Harbeth designer's objective is to make loudspeakers that contribute little of themselves to the music passing through them.

Identifying system components for their sonic neutrality should logically proceed from the interpretation and analysis of their technical, objective performance, since deviations from a flat frequency response at any point along the signal chain from microphone to ear is likely to create an audible sonic personality in what you hear. That includes the contribution of the listening room itself. To accurately reproduce the recorded sound, as Harbeth speakers are designed to do, you would be advised to select system components (sources, electronics, cables and so on) that do not color the sound before it reaches the speakers.

For example, the design of and interaction between the hifi amplifier and its speaker load can and potentially will alter the sound balance of what you hear. This may or may not be what you wish to achieve, but on the face of it, any deviation from a flat response - and the frequency balance of tube amplifiers are usually influenced by their speaker load - is a step away from a truly neutral system. HUG has extensively discussed amplifiers and the methods for seeking the most objectively neutral amongst a plethora of available product choices.

HUG specialises in making complex technical matters simple to understand, aiding the identification of audio components likely to maintain a faithful relationship between the recorded sound and the sound you hear. With our heritage of natural sound and pragmatism, HUG cannot be expected to be a place to discuss the selection, approval or endorsement of non-Harbeth system elements selected, knowingly or not, to create a significantly personalised sound. For that you should do your own research and above all, make the effort to visit an Authorised Dealer and listen to your music at your loudness on your loudspeakers through the various offerings there. There is really no on-line substitute for time invested in a dealer's showroom because 'tuning' your system to taste is such a highly personal matter.

Please consider carefully how much you should rely upon and be influenced by the subjective opinions of strangers. Their hearing acuity and taste will be different to yours, as will be their motives and budget, their listening distance, loudness and room treatment, not necessarily leading to appropriate equipment selection and listening satisfaction for you.

If faithfully reproducing the sound intended by the composer, score, conductor and musicians in your home and over Harbeth speakers is your audio dream, then understanding something of the issues likely to fulfill that intention is what this forum has been helping to do since 2006. Welcome!"


Feb. 2018
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Harbeth older and discontinued models:

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  • #46
    Harbeth LS3/5a - the facts about why production ended

    There seems to be some misunderstanding about why the original KEF woofer/tweeter based BBC LS3/5a ceased production more than ten years ago. This terminated not only the production of the well regarded Harbeth LS3/5a version but all other KEF-based LS3/5a offerings.

    The facts are these: KEF, manufacturer of the T27 tweeter and B110 (SP1228 variant) made a business decision to cease production of these parts. It coincided with KEF being taken over by the acoustics division of Gold Peak (GP) the world's largest battery manufacturer. Naturally, large efficient corporations such as GP have management priorities and a business strategy which is under constant review and obviously designed to maximise shareholder value. When this trickles down to individual production facilities, local management consider the balance of hassle v. profitability v. demand and products are axed because the income they generate does not meet business criteria. This sealed the fate of the T27 and B110.

    For some reason - perhaps due to the number of simultaneous licenced suppliers of the LS3/5a - the consumer perceived a price ceiling for the small box beyond which the demand dropped dramatically. In short, the public just wouldn't pay above a price point (of around ?600 UK pounds) when in fact the 'correct' full-costing retail price was over ?1000. In consequence, every time KEF quite reasonably passed on additional manufacturing costs to us licenced manufacturers of the complete speaker, we either couldn't pass them on to the consumer, or we refused to accept them. You can imaging that we and the other LS3/5a makers were in a pincer movement between ever increasing material costs and our customer's willingness to pay. Inevitably, KEF ceased production of the drivers, closed the UK hifi drive unit production lines, closed the factory, mothballed and/or wrote-off any residual component stock and that seemed to be that.

    Commercially, the demise of the LS3/5a effected Harbeth negligibly because in as we'd edged up the ex-factory price we'd already seen LS3/5a sales demand drop to a low level and of course, the BBC had been buying the Harbeth P3/Monitor 20 for many years. So we were in the protected position that I'd anticipated; should either the KEF parts (for the LS3/5a) or SEAS parts (for the P3) dry up, we'd still have a mini-monitor to sell.

    Unbeknown to Harbeth, KEF UK had an ongoing demand for some of the older-style woofers for earlier KEF Reference series, for then current KEF in-wall models and general spares associated with their long warranty period but these older 'classic' designs used tooling, glues and techniques which were not transferable to their impressive modern facilities in China. As a former KEF customer we had maintained good relations with them and as by now we had a long experience of making the Harbeth RADIAL drivers we offered to manufacture any 'classic' parts that KEF needed. A formal knowledge-transfer arrangement was made between KEF and Harbeth covering just these parts on a need-to-know basis. KEF assigned a semi-resident engineer at Harbeth to train us how to make their woofers, from their drawings and using parts free-issued from KEF and following closely the methods KEF had refined over many years. We were considered a 'foundry' for their woofer needs. Harbeth invoiced KEF solely for labour costs (with an agreed profit margin). KEF supplied Harbeth with bulk stock and later kits of parts to assemble a range of drive units using component stock salveaged from their stores from when they closed the UK woofer lines.

    Purchase orders arrived at Harbeth driectly from KEF's purchasing department and we would check the stock of parts they'd free-issued to us, identify any shortages and then make, test, package and deliver complete woofers to them. Any material shortages were flagged and KEF took care of sourcing whatever we needed. The key point is this: we were not authorised to make any drive units until we received a covering Purchase Order from KEF otherwise we would have eaten into their stock and this would have got us into some trouble. Now, concerning the B110 woofer for the LS3/5a, although we were trained to make this part, and in fact did make about 20 pcs. to prove that we could, we did not receive additional POs from KEF and consequently KEF didn't free-issue components parts to make more.

    During the five years that we were making various woofers for KEF I do not recall more than a handful of end-user request for B110s and I'm sure that KEF themselves only experienced a trickle of enquiries - not sufficient to warrant buying and pre-paying for bulk stock of necessary parts (from their overseas factories). We would have been pleased to manufacture the B110 here as it was equally profitable for us as any other KEF unit, but without POs and parts that was impossible.

    I hope that this finally lays to rest the ill-founded rumour that Harbeth were instrumental in 'killing off the LS3/5a' as that is wholly untrue.
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

    Comment


    • #47
      Re: Harbeth older and discontinued models:

      Hi,

      I currently have a pair of P3s which are great - but I am considering upgrading. I was wondering if a naim nait 5i would drive a pair of HL5s circa 1994?

      Cheers

      Andy

      Think I originally posted in the wrong section - sorry

      Comment


      • #48
        Re: Harbeth older and discontinued models:

        Nait 5i is a solid amp capable of about 70wpc so will have no trouble with the HL5.

        Comment


        • #49
          Re: Harbeth older and discontinued models:

          thanks very much

          Comment


          • #50
            Re: Harbeth older and discontinued models:

            Hello, all

            I hope I'm in the right place here, as I realize that the Monitor 20 is still current. I was wondering if the new 5 inch Radial driver has been, or will be, retro-fitted to this speaker. I've also always been curious as to the internal difference between the M 20 and the old HL-P3ES 2/new P3ESR, as they appear to be identical externally.

            Thanks.

            Bob LaBarca
            State College, PA
            USA

            Comment


            • #51
              Re: Harbeth older and discontinued models:

              The Monitor 20 with the SEAS woofer (and tweeter) is indeed current. As we are still selling this speaker and have good stocks of parts, we have no plans to make any changes at this time.
              Alan A. Shaw
              Designer, owner
              Harbeth Audio UK

              Comment


              • #52
                Actives .... and after-care/support

                Just to clarify again our position on all Harbeth actives. This is what we have been saying to callers for many years now. See here and here.

                There is no after-care support for Harbeth active speakers. As a policy decision they were never sold outside the UK. All UK installations were by hand, in our own vehicle direct to the studio. There were no suitable cartons made as these were not necessary for personal delivery. The original Monitor 40 Active with inbuilt electronics is now about ten years old, and were sold originally with a one year warranty. We do not think that these old, complex active speakers are robust enough to be transported by standard courier where they will be thrown around. We cannot enter into any correspondence about circuits, servicing, modifications or other matters concerning these long out of production speakers. Please also be aware that there are no new spares of the 12" woofer used in the M40 active.
                If you are interested in the Harbeth flagship we strongly recommend the Monitor 40.1 passive, which used with an external rack-mount power amplifier is eminently suitable for studio use. Thank you for your understanding.
                Harbeth PR,
                Harbeth UK

                Comment


                • #53
                  Re: Harbeth older and discontinued models:

                  Disappointing. When we explain in minute detail why we cannot service ten year old active speakers we are criticised for not being more proactive and for being disinterested. Seems we can't win by being honest! Folks buying on Ebay please have realistic hopes of what miracles we can or can't perform. The weakness of the original M40 active is the circuit board connectors. There are many. Even if the ten year old speaker is serviced here, there is no guarantee that it will arrive a continent away in good working condition. That would cause untold customer stress.
                  Harbeth PR,
                  Harbeth UK

                  Comment


                  • #54
                    Re: Harbeth older and discontinued models:

                    Originally posted by harbethpr View Post
                    ... The weakness of the original M40 active is the circuit board connectors. There are many. Even if the ten year old speaker is serviced here, there is no guarantee that it will arrive a continent away in good working condition. That would cause untold customer stress.
                    This is absolutely true. Providing that the speakers are not disturbed they should work indefinitely. But I will not take the risk that upon return to a customer (if they could be repaired) that they'd not work.

                    As far as Actives and their support is concerned we have laid out the situation with clarity. I really regret if any customers have purchased these actives, but to the very best of our knowledge, we have been completely honest if they contact us before purchase as to the situation. If they ignore us and purchase, or purchase without checking with us, we will unfortunately have to break the news to them.
                    Alan A. Shaw
                    Designer, owner
                    Harbeth Audio UK

                    Comment


                    • #55
                      Converting actives to passives ....

                      One of our members has made a suggestion that may solve the M40 Mk1 active situation. For a fixed price we could theoretically convert these to passives. But this is fiddly work and will need to be carefully costed. It would probably cost about 60% of buying a new pair of M40.1 passive.

                      NOTE: It is impossible to convert the M40 Mk1 active (inbuilt electronics) to M40.1. I repeat - impossible to convert M40 active to M40.1 because the bass unit cut-out is completely different and the M40.1 bass unit cannot and will not fit into the M40's baffle. Nor will the M40.1 crossover drive the VIFA 12" bass unit, nor the M40 crossver drive the new M40.1 Harbeth-made bass unit. Also, the midrange drivers are different and would need to be replaced. The tweeters would be the only common part.

                      We are not able to offer hybrid baffles that fit the original M40 cabinets which are subtly different to the M40.1 cabinet. So that basic de-activisation of the M40 is as far as we are able to take the conversion so please do not ask how/when/how much to convert M40's active or passive to M40.1. It just cannot be done.

                      This conversion from M40 active to M40 passive assumes that the original VIFA 12" bass unit is in pristine condition.
                      Alan A. Shaw
                      Designer, owner
                      Harbeth Audio UK

                      Comment


                      • #56
                        Seeking information about the older Harbeth HL Monitor Mk II.....crossover point?

                        Regarding the Harbeth HL Monitor 2 (Mk II) loudspeakers. I understand that the crossover frequency on the original HL model was 2kHz. Is this the same crossover point in the Mk II version or did it change?

                        Cheers!

                        {Moderator's comment: No it was about 3.5kHz. A 1" tweeter cannot be operated safely at 2kHz or below.}

                        Comment


                        • #57
                          Crossover

                          RE: Moderator's comment: Thank you for your reply. According to this document, http://www.harbeth.co.uk/hifispeaker...images/mk1.pdf , the crossover frequency on the original HL Mk 1 was, in fact, 2kHz. Are you saying this was changed to approximately 3.5kHz for the Mk II version? I am confused. Can you please clarify?

                          Comment


                          • #58
                            Obsolete crossovers

                            The original HL Monitor Mk1,2,3 ended production in about 1985, that's twenty seven years ago. We have no more information than you have about the crossover. If Mr Harwood's 1977 sales leaflet says 2kHz then that must be taken as correct. All three models were long finished when the company changed hands. It is unlikely to be different for Mk1 2 or 3 as only the woofer changed and maybe that resulted in small crossover changes. Or maybe none at all.

                            Why is this point of interest to you?

                            Comment


                            • #59
                              A DIY modern Harbeth?

                              I am interested because I have an opportunity to purchase a pair, however I have no interest in the vintage tweeter and would upgrade the unit to a modern SEAS unit similar to the one used in the Monitor 30.

                              It's unbelievable to me that the specifications for the Mk II will forever remain a mystery and that of all people, the Harbeth company themselves would not know. Surely, as meticulous as the current owner/designer seems to be, I would imagine such records would be preserved and maintained.

                              I wonder if there is some reason why these specifications are deliberately withheld? There are claims on other hi-fi discussion boards that Harbeth deliberately withholds information about older models in order to motivate people to purchase new product. I have a hard time believing that this is true, yet in light of this thread...I can't help but wonder.

                              I'd love to have a pair of Monitor 30's. I simply can't afford them right now, that's all.

                              Comment


                              • #60
                                Harbeth Mk1, 2, 3, 4: a poor man's way to ultimate hi-fi?

                                Originally posted by RogerMBond View Post
                                I am interested because I have an opportunity to purchase a pair, however I have no interest in the vintage tweeter and would upgrade the unit to a modern SEAS unit similar to the one used in the Monitor 30.

                                It's unbelievable to me that the specifications for the Mk II will forever remain a mystery and that of all people, the Harbeth company themselves would not know. Surely, as meticulous as the current owner/designer seems to be, I would imagine such records would be preserved and maintained.

                                I wonder if there is some reason why these specifications are deliberately withheld? There are claims on other hi-fi discussion boards that Harbeth deliberately withholds information about older models in order to motivate people to purchase new product. I have a hard time believing that this is true, yet in light of this thread...I can't help but wonder.

                                I'd love to have a pair of Monitor 30's. I simply can't afford them right now, that's all.
                                OK, I'd like to nip this in the bud before you go any further. First, the speakers you are considering purchasing were made over thirty years ago (if they are Mk 1/2) by Dudley Harwood himself. When I took over in 1986 the Mk4 was just in production, and Harwood being a boffin and concerned only with the latest invention, had mentally already distanced himself from the polypropylene cones of the Mk 1, 2, and 3. He gave me no information whatsoever on the Mk 1, 2, 3 except what you already have as a PDF. No circuit diagrams. No bills of materials. Nothing. And frankly, as I was in effect a clean start, I didn't see the need for it at the time. I started with the recently introduced HL Mk4, and the only documentation for that was a hand drawn circuit.

                                The Mk4 used an Audax woofer, and that in effect severed the relationship Harwood had had with Rogers, who made the Mk 1, 2 and 3 polypropylene woofers and that was not a relationship I needed to reactivate. So spares for these antique Harbeths have never been available, and with the demise of Audax themselves fifteen or so years ago, that ended the supply of tweeters.

                                The woofers and tweeters were made to the prevailing normal commercial specification of thirty years ago, long before cyanoacrylates (super glues) were introduced to the speaker industry. That means that the weakest parts of these old speakers are the glue joints which are, by now, held together by not much more than a wing and a prayer. You'll see evidence of that as dark staining around the rubber surround (in the Mk 2 and 3) where the contact adhesive has attacked the cone. The Mk1 has a different problem: the clear PVC surround has a tendency to return to the flat state (it has material memory) and that means the half-roll may have flattened out. The normal anticipated service life of such a speaker at the time would have been up to ten years at best, so they are now approaching three times their design life. Common sense says that they are extremely fragile. If you buy a car from an elderly person who has just pottered around the village you must expect the clutch to fail. It's the same problem with speakers: the shock of the duty cycle the new owner gives them strains fragile parts.

                                There is also an issue with (all?) similar Audax tweeters, including their big-brother soft-domes (37mm?): the hair-thin voice coil lead-out wires corrode and fracture for no apparent reason. But again, that's typically after 15 years so well beyond the design life.

                                To stand any chance of grafting a modern tweeter onto an old Harbeth (or indeed any commercial speaker) you will need some knowledge and certainly test equipment. The chance of making a text book crossover and successfully optimising by ear is, if I am honest, nil. You risk placing yourself in a state of permanent anxiety whereby you cannot enjoy the music because you are forever jumping from the hot seat to tinker with the crossover, just as I did as a teenager. It never sounded "right". After what seems like years of tinkering I finally admitted defeat and bought a pair of then-BBC monitors and got on with the music.

                                Your best bet would be to pay as little as possible for these speakers commensurate with the risk that they could/will fail at any moment and try and track down some clone Audax tweeters, which I have heard are available in the Far East. Don't do anything other than drop them in, settle back and consider the surgery complete.

                                It is true that we have mortgages to pay, mouths to feed and to run a viable supply and after care support operation for our over forty distributors. If we had spares we could, of course, make these available. But we don't and never will as key suppliers - Rogers, Audax just to mention two - closed their door many years ago.

                                I hope that helps.

                                P.S. Whilst I hesitate to counter Mr. Harwood's claim of 2kHz crossover frequency, there is ambiguity. Did he mean electrical 2kHz or acoustic 2kHz? It wouldn't surprise me if he said one but cunningly meant the other and wasn't going to waste the printed paper!

                                P.P.S. I must be going soft ..... I've found for you the one frequency response plot I inherited. It would have been measured at either BBC Kingswood Warren anechoic chamber or at the Rogers chamber in Mitcham. I think it proves my point. Written in Harwood's own hand is "with and without Daclon at 4.5 inches". I'd suspect that the Daclon is the acoustic grille foam which is virtually acoustically transparent hence very small differences on/off. That implies Mk1, 2, 3 or 4 all of which used the same tweeter. I think you can see for yourself that the crossover frequency shown here is, as stated before, probably around 3kHz, not 2kHz.

                                It's now 2320 and I'd like to conclude this and get to bed. You know as much as I do now.
                                Attached Files
                                Alan A. Shaw
                                Designer, owner
                                Harbeth Audio UK

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