"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. Deviations from a flat frequency response at any point along the signal chain from microphone to ear is likely to give an audible sonic personality to the system at your ear; this includes the significant contribution of the listening room itself. To accurately reproduce the recorded sound as Harbeth speakers are designed to do, you would be best 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 will alter the sound balance of what you hear. This may or may not be what you wish to achieve, but any deviation from a flat response is a step away from a truly neutral system. HUG has extensively discussed amplifiers and the methods for seeking the most objectively neutral among a plethora of product choices.

HUG specialises in making complex technical matters simple to understand, getting at the repeatable facts in a post-truth environment where objectivity is increasingly ridiculed. With our heritage of natural sound and pragmatic design, HUG is not the best place to discuss non-Harbeth audio components selected, knowingly or not, to introduce a significantly personalised system 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. Our overall objective here is to empower readers to make the factually best procurement decisions in the interests of lifelike music at home.

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. Always keep in mind that without basic test equipment, subjective opinions will reign unchallenged. With test equipment, universal facts and truths are exposed.

If some of the science behind faithfully reproducing the sound intended by the composer, score, conductor and musicians over Harbeth speakers is your thing, this forum has been helping with that since 2006. If you just want to share your opinions and photos with others then the unrelated Harbeth Speakers Facebook page may be for you. Either way, welcome to the world of Harbeth!"

Feb. 2018
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Harbeth HL MK2 For my Log Cabin, what glue can I use to re-seal cone to surrounding rubber?

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  • Harbeth HL MK2 For my Log Cabin, what glue can I use to re-seal cone to surrounding rubber?

    Hi guys, I recently purchased some older Harbeth HL MK2's for my Log Cabin (going alongside 4 Harbeth Xpressions with new cones) Just to add some temporary Bass to the situation.

    The only downside is on one of the older Harbeth HL MK2's, the cone seems to have become dis-attatched to the rubber around it (shown in image below) Just wondering if anyone could suggest what glue would be best to re attatch it to the surroundings?

    I do have some spare 'Rubber Cement' but not sure if this would be best fitted for the job? Just wondering what kind of glue would be best to use on the old MK2 polypropylene cones?? Any advice would be appreciated. Many thanks!
    Attached Files

  • #2

    Anyone have any ideas? Would like to make a start on fixing them tonight -
    Best regards


    • #3
      Before gluing: lock the voice coil/cone height

      Sorry for the delay: I overlooked your post.

      The key point is that without a jig, there is a danger that you will glue the cone/surround such that the voice coil is slightly off-centre and will rub. The best way, as you have already removed the entire surround from the cone (inadvisable), although this may alarm you, is to peel off the dust cap (you will re-use it) and find a sheet of paper that can be slid down into the tiny gap between the inside of the voice coil and magnet pole piece. The idea is to lock the cone/coil with a suitable shim at the correct rest height before attempting to glue the surround onto the cone. If the coil is pushed too deep or stands too proud at rest, the surround will have to stretch to make contact with the cone, which will greatly reduce the excursion possibility of the drive unit.

      Do that first, then please report back. Rushing ahead now will negate your chances of a successful repair.
      Alan A. Shaw
      Designer, owner
      Harbeth Audio UK


      • #4

        Thank you for the detailed response, I shall try this, also another part of my question is just, what kind of glue to use, Areldite or Rubber Cement? Kind regards


        • #5
          Glue suggestions


          Rubber cement is for glueing rubber to rubber. It works by effectively melting the surface of rubber so the two pieces mix and fuse. It's for repairing things like the inner tubes of bicycle tyres and unlikely to glue anything to polypropylene.

          Araldite is extremely strong however it is unlikely to adhere well to rubber, and it does not function well in any kind of flexing situation because it sets absolutely rigid.

          I recommend impact adhesive - since you have a log cabin it's unlikely you are in the UK so this may have another name in your country, but it is very tough and flexible. It's the smelly stuff that people sometimes abuse because it is full of the solvent toluene, usually a dull yellow colour. There are many brands. You apply it to both sides, let it become tacky and then press them together and in general they don't come apart again.