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At its inception ten years ago, the Harbeth User Group's ambition was to create a lasting knowledge archive. Knowledge is based on facts and observations. Knowledge is timeless, independent of the observer and can be replicated. However, we live in new world in which objective facts have become flexible, personal and debatable. HUG operates in that real world, and that has now been reflected in the structure of HUG.

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{Updated Jan. 2017}
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Harbeth HL Compact 7ES-3 specific

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  • Spade connectors

    Originally posted by Don Jr View Post
    The web site states 4 mm binding posts on the C7. Is that the diameter of the hole for bare wire? I bought Audioquest Rockefeller cables with spades at the speaker end and the spades were too small to fit the posts. The spades are rated for 1/4" & 5/16" posts. It's not the end of the world as I replaced the ends with bananas. Just wondered if anyone else is using spade connectors or if anyone has run into this?
    Hi Don Jr, 4 mm is the banana hole diameter size, I use a 9mm gapped spade to match with the Harbeth speaker terminals.
    Thanks Jason.


    • My first truly great speakers

      Originally posted by A.S. View Post
      I have the highest respect for the BC1 and its designers and a good specimen still performs well if not fully to the original published specification. I owned BC1s for many years and these are my personal feelings about them. As we review the history of the BBC's speaker project and we should remember that the BC1 was the product of a particular time, to meet a very specific BBC need. It was luck indeed that the BC1 'leaked out' into the domestic market. In contract, the Harbeth Compact 7ES3 is a modern speaker designed in the 96k digital era with wide application in modern listening environments, wide musical tastes and with high resolution to get the best from modern equipment, ultra-quiet sources and wide dynamic recordings.

      As I see it, the BC1 was designed in the (hissy pre-Dolby) analogue mid-60s for near-field operation in smaller BBC control rooms where the sound engineer could reach out and touch the speakers. This implies that the listening level was low. In turn, according to the way that the human ear operates, listening at a low level implies that the bass frequencies are subjectively reproduced at a lower level than ideal. The designers were aware of this issue and to some extent compensated for this in the design. However, the BC1 was not designed for far-field listening at higher sound pressure levels where self-evidently it 'runs out of steam' in the bass register. Remember - in the mid 1960's when the BBC were developing the LS3/4 (which became the BC1) rock/pop music was in its infancy and the elitist BBC did its very best to ignore it; there was no Radio 1; the Light Programme served up 'popular entertainment' comprising big bands, folk, jazz and classical music. This pre-pop era was one of soft bass and low sound pressure levels, a much less demanding duty for the loudspeaker to perform. I myself burned-out two or three BC1 bass units on pop music and I was not playing that loud!

      The 'BC' name refers to Bextrene Cone, a first generation plastic (polystyrene actually) and this material has well-documented sonic colourations, typically of a 'quacky' or beaky sound. During the plastic research phase the BBC discovered that if PVA (wood glue of a particular type) was generously painted onto the front and back of the cone by hand, these colourations could be tamed - but - at the cost of somewhat increased cone mass (PVA is heavy) which pressurises the bass unit's loudness/mass/excursion/colouration/hangover/efficiency issues. As you can see, taming the colouration leads to other spin-off problems.

      In time, the BBC concluded that Polypropylene (second generation cone plastic) was a better material being far lighter than bextrene and not (they said) needing the PVA dope treatment. At that point - 1977 - Harbeth was founded by the BBC's Head of Speaker design (Dudley Harwood) and the polypropylene- based HL monitor was born with an undoped PP cone. Harwood held the patent on PP cones under a deal with the BBC who had by that point decided to replace their BC1 stock with new BBC-designed speakers (LS5/8, LS5/9) which could play much louder and with lower colouration and by about 1988 apparently all BC1s had been decommissioned. The BC2 with its 1.5" voice coil was designed to offer a lounder/more efficient BC1 but this trade-off changed the overall acoustic signature. Speaker design is all about compromises.

      By about 1983, Harwood/Harbeth was made aware of a new, third generation cone material candidate being investigated by Audax, France, and convinced by the performance, he decided to dispose of his PP patent (now seemingly owned by Sony via many changes of hands), abandon PP and started production of the HL Mk4 with the bought-in Audax TPX cone. At that point I became involved with Harbeth. I had used BC1s (and the PP-based SP1s) daily for about 10 years and I knew their sound very well but the new TPX cones were a revelation. I liked their clean, transparent sound so much that, well, I bought Harbeth and gave up my day job at NEC Corp..

      Now, the Harbeth HL Compact 7ES3 uses a fourth generation cone material we call RADIAL (Research And Development Into Advanced Loudspeakers) and which was developed in collaboration with British Governments funding. We manufacture the RADIAL woofers in-house here at Harbeth. Unlike all the previous materials mentioned, our RADIAL is injection moulded in our own (expensive) tool because it is a compound of granules, not a general-purpose sheet material bought on a roll from a plastic company as bextrene or PP. It is engineered for its acoustic properties and every cone is just like every other. The cost is high but so is the performance.

      What does this translate into? Well, the inner-clarity of the C7ES3 is really astonishing as you would expect for a 4th generation material and it is as if a thin veil has been removed from the speaker: the balance will be instantly familiar to you as the 'BBC balance' but you'll enjoy hearing micro-details that were absorbed (as heat) in the earlier materials. The bass handling, maximum spl, extended HF and cosmetics are all enhanced too and the frequency response is flatter.

      Hope this helps.
      To add to Alan's post, a personal experience. I owned BC1s for over 30 years and would agree, more or less, to what has been written. At low level, playing classical or folk music, the BC1 performed well. I never ran them at high levels. If rock type music was played, at highish levels the speakers could sound stressed. That is the only way I can describe it.

      Due to a house change, the Spendors were bass heavy in my new room and no amount of positioning could alleviate it. After trying various small speakers, including LS3/5as, I bought a pair of early HL Monitors. To me, they have the BBC-like characteristics of midrange and top, but the bass end is much less heavy . They have been a very good replacement for the BC1s.

      With ref. to the reproduction of micro details in the music, as I also own a pair of P3ESRs on another system I know exactly what Alan means. I will always have great respect for my BC1s. They were the first truly great speakers I owned
      Last edited by Miles MG; 07-10-2014, 04:25 PM. Reason: Change letter. 'of ' to 'or'