Technical questions to Harbeth's designer

[Thorsten Rock]

Hi Alan,

I still have two old 8" woofers by Harbeth which I bought in the late 1980s. They are marked LF8MkIII and bear a golden star (probably for matching?).

Now I suspect these are the drivers which were sold in Germany without consent of Harbeth (you said something about those in the old forum - yes, they were advertised as genuine Harbeth drivers) - but they still look very similar to those used in the H.L. Monitor Mk III (I hope these are real Harbeths at least).

Do you still have the cabinet (and port) dimensions and the schematics for the crossover? I know that there's much more to speaker design than putting the parts into some home-made box, but as I still have the drivers here I hope it will make a very decent low-budget speaker at least - even if it won't equal the quality of your current products.

Thank you very much,
with kind regards,
Thorsten

[kevint]

Hi Alan,
Curious to know how ready Harbeth speaker is on RoHS compliance regards. I learnt from a magazine that a UK speaker manufacturer has to move some of production processes offshore in order to use typical lead solder on their crossover board which the manufacturer thinks sounds better than lead-free solder.

What kind of solder does Harbeth use? Does it matter?

Kevin

[A.S.]

I think you're kidding me about the sound of solder! How on earth can there be any difference? Marketing - merely marketing talk (IMHO).

We regrettably ceased using leaded solder a few months ago. It's a pity - the visual quality of solder joints was better but mechanically and electrically, we are assured that there are no differences.

[Vangelis]

Hi Alan, A while back I ordered a pair SHL5s in tiger ebony. I needed a darker finsh so I ordered them sight unseen. I'm excited about the speakers and I was wondering if you have any photos of Harbeths in the Tiger Ebony? A photo would help ease my wait. Thanks.

[macolive]

Hi Vangelis,

Allow me to post a picture of my SHL5 Ebony. Just in case Alan is too busy.

http://i8.photobucket.com/albums/a16...huncovered.jpg

[Vangelis]

Macolive, Wow, what a great photo. Its the first image I've seen of the Tiger Ebony that I ordered. It will be worth the wait. Thanks Again.

[macolive]

I forgot to say congratulations! You will definitely not be disappointed. It's a glorious sound coming out from a gorgeous speaker.

[Jeff Day]

Hi Alan,

The grills on my new Super HL5 are a very tight fit and I was wondering if you have a recommended method for removing the grills that doesn't put the cabinets' veneer at risk from a nick or scuff, as I want to photograph them with the grills off (the Tiger Ebony is beautiful by the way).

Kind regards,

Jeff

[A.S.]

Jeff - that's a very good question, and one we were discussing in the office recently as we studied a customer's picture which clearly showed that a screwdriver (or similar) had been used to lever-off the grille.

We are planning to make a little video, but in the meantime I'd say pinch some cloth between thumb and first finger and give the grille a really good tug. Yes, sometimes they are tight, but that's a better than loose and buzzing and as you may know, I recommend that the grilles are left fitted for listening - counter-intuitive maybe but the response is actually smoother with them on so effective is the grille design.

By the way, here in the UK we say "grille" not "grill".

[Jeff Day]

Thanks for the tip Alan - appreciated. I tried pulling it off with my fingers as you recommended but couldn't get a firm grip on the edge, so I covered a pair of round-nose pliers with masking tape to protect the cloth and veneer from the metal of the pliers. The pliers allowed me to grip the edge of the frame & cloth tightly and easily & neatly extract the 'grille' without any damage to the cloth or veneer.

Best,

Jeff

[Shutterbox]

Alan, how about fixing/stapling a short piece of fabric to the side of the frame of the grill, on both sides of the grill.

So that when the user holds both the short pieces of fabric(short so as not to affect the looks of the speaker, if thats a concern at all), and grill can be remove w/o warping the grill frame.

[A.S.]

That's a very good idea. I'll talk it over with the grille maker ladies. I guess it's going to rely entirely on the strength of the glue.

[KT88]

Hello,all. I have the opposite problem with my Compact 7ES-2's. The grilles seem to be too loose in their channels and will buzz/vibrate at certain lower frequencies. Any suggestions for a fix on this? Thanks. Bob LaBarca

[A.S.]

Ah - steel and wood each with their own unique characteristics. This is quite easy: remove grilles, apply a little outward bias on both long sides and refit.

[James Beltran]

Alan,
Being a contented owner of numerous models over the years( and still hanging on to them) I am happy to say that if it is time to change my SHL 5 it's going to be the M40 for me. For that I need to buy another house.But in the meanwhile, I am wondering if I should attempt to tighten the screws on the front and rear panels as they may be lose after years of use and is there any advice on the level of tightness which allows the speakers to perform at it's best.
Best Regards
James Beltran
Malaysia

[oferab]

Hi dear harberth designers
I have a question about active vs. passive loudspeakers design,
regarding the benefit of active loudspeakers design, among them are better crossover, more efficienty, better amplifier matching, more control on the frequency response and more, why don't Harbeth produce more active loudspeakers, and only have one model which is active, is it because the audiophile market is not mature enough for Active loudspeakers, or are there other reasons
Regards
Ofer

[A.S.]

... better crossover, more efficiency, better amplifier matching, more control on the frequency response and more

Interesting question. Actually, the sonic advantages of Active are really small compared with passive. It is not true to say that an Active crossover is necessarily better - it is certainly much more complicated.

In my opinion the correct way to design a speaker system is this:

1. Design and optimise passive version. This then becomes the template for the active filter circuits.

2. Design the active filters from the passive filter template.

3. Adjust time delay etc. in the active if desired.

Commercially, the hifi user wants maximum choice. This speaker + that amp. If he buys active he has no choice of amp. Not ideal for him. In the studio what they will pay for is convenience - they are not much interested in the active v. passive arguments which they really don't understand.

[leekb]

I brought home a brand new S-SHL5 yesterday. The grille fits so tightly I do not think I will ever be able to remove the grille to catch a glimpse of the drivers. Alan, how's the little video coming along? It will be useful for those who have problems removing the grille, including me.

[A.S.]

Could you email me privately with the serial numbers so I can investigate this please? Can you also tell me your room temperature now?

Since I'm not aware of any really tight grille/cabinets here I think expansion of the grille frame (steel) or cabinet due to temperature is a factor.

The video - yes, I will talk to our PR man about that next week.

[Jeff Day]

Hi Alan,

I've had the same problem with my grilles being too tight. In fact after my 6Moons article went live I was demoing the speakers for visitors and ended up tearing the grill fabric on one of the grilles while removing them. Any chance I can get it recovered?

Kind regards,

Jeff