Poll

Please indicate what kind of loudspeakers do you use in your main listening environment (RRP ZAR)

Small Bookshelf-below R20K
11 (9.4%)
Standmount Between R20-R50K
9 (7.7%)
Standmount between R50k-R100k
2 (1.7%)
Floorstander below R20k
27 (23.1%)
Floorstander between R20k-R50k
33 (28.2%)
Floorstander between R50K and R100K
11 (9.4%)
Floorstander over R100k
12 (10.3%)
Planars or electrostatics (can incl  conventional bass drivers)
9 (7.7%)
Horns (primarily based on typology)
3 (2.6%)

Total Members Voted: 117

Author Topic: Air Loudpeakers  (Read 19029 times)

Offline Air

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Re: Air Loudpeakers
« Reply #210 on: September 03, 2017, 10:38:12 AM »
A bit of feedback for those who are interested in our progress.

We are forging ahead and have learned to deal better with time schedules of our suppliers. Working with professional suppliers brings the inevitable that our work is small in comparison to the more profit generating long runs production cycles and development work often is a secondary priority. Production of ticked parts is easier. As an example, the machining of one of our molds will imply a 2-day stop of the normal production line of the bent wood supplier. We could look for a different machining shop and outsource the CNC machine at the risk of quality, purely perhaps of what might be lost in translation and rework which brings costs and frustration with it, so we need to be patient and bet on the quality of time as the key principle of how we tackle the project.  All of this doesn't imply we are not making progress but highlight some of the reasons why we are not progressing at a snail's pace. So we need to manufacture 2 major parts, that has been designed and all the initial testing and prototyping have been done, the bent wood panels and the midrange enclosure.

Our focus, while we wait for the final wood-panels is to work on the finishing details. Earlier in the year, I gave feedback on the aluminum parts finishings and we ran a few test with various options, such as polishing, brushing and blasting as a pre-anodizing step. We liked the blasting option as it creates a satin and even finishes. Polishing is too bling and won't fit the style of the other wood finishes, brushing(often the standard for amps/speakers) are nice but the tolerances are not predictable and can mess up the wave guide profile of the tweeter for example. Blasting we liked and the initial suppliers work looked good on the small 10cm by 10cm test pieces. However, on larger surfaces, the results were uneven as it is often done by hand in SA and not by robot control. So we contacted various suppliers and had to systematically weed out the better quality services from the ones that can't do it well enough. Eventually, we found a supplier that we think can pull it off with consistency and we got them to to the back of the baffle and the pics below show the results. It was done with micro beads but we will use virgin micro beads, at a cost, of course, to try and take it even one step further.




After the preparation phase we will anodize, first, we a thin clear layer and then with black, to hopefully end up with a very high-quality finish.

So hold thumbs.  :pray:


Offline Shonver

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Re: Air Loudpeakers
« Reply #211 on: September 03, 2017, 12:03:24 PM »
Here is an alternative that can yield repeatable results, with regards to aluminium finishing. You will need to standardise (for repeatability) the process. After cleaning up/polishing the surface, immerse the part in an etching bath (rinse afterwards). Caustic soda works, but that is just a DIYer's solution: there may be better products. You will have to control concentration & purity/saturation, temperature and time, as it is a subtractive process. This produces a fine satin finish. At this stage, the surface is very prone to damage, so the very next step must be anodising. You can play with masking of critical/hidden surfaces and also for making patterns.

Also, I forget whether you have addressed this problem before: make sure you specify a grade of aluminium with repeatable properties. This may be more costly than run-of-the-mill grade ally, but the unspecified grades can yield a lot of variability when it comes to anodising in terms of finish and colour (especially if you are anodising black).
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Offline Air

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Re: Air Loudpeakers
« Reply #212 on: September 04, 2017, 09:34:18 AM »
Thanks, Shonver,

I will do some research about your suggestion of an etching bath. Will also, ask the anodozing supplier about their thoughts on the option.

We have specified the aluminum as 6082 T6 based on the machinability and suitability for anodizing, as well as corrosion resistance and availability in SA, hopefully, to get repeatable results.

Of course, we can take the easy way out and that is to powder coat but from a durability perspective and our own style/finish preference, anodizing is the 1st price.

Stefan

Offline skollie

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Re: Air Loudpeakers
« Reply #213 on: September 04, 2017, 10:10:34 AM »
Caustic soda does work. I have used it several times when making replica armwands but professional anodisers don't use this process.

When I anodise cartridge casings, I use phosphoric acid heated to 100degrees C. This processis also known as 'chemical polishing' and gives a beautiful chrome-like finish - except in places where there is impurities in the aluminium used.

skollie
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Offline Air

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Re: Air Loudpeakers
« Reply #214 on: September 04, 2017, 05:22:43 PM »
Thanks, Skollie,
Do you have a detailed pic of the kind of finish that is achieved with this process?
Stefan

Offline skollie

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Re: Air Loudpeakers
« Reply #215 on: September 04, 2017, 08:04:11 PM »
Yes, but I cant't post pics here. One item will be a cartridge casing 'chemically polished' only and the other item (a headshell I made) was processed in phosphoric acid and then anodised.

I can email the pics to someone here. Please note I am not at my workplace for most of tomorrow and it is too late now to take good pics..

skollie
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Offline Nicholas

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Re: Air Loudpeakers
« Reply #216 on: September 05, 2017, 12:26:50 PM »
Hello Stefan,

Really appreciating and respecting your commitment to quality on your project, i love it.

Regarding your engineering suppliers slow service for prototyping, in my engineering experience (not DIY) once you have built the relationship and more importantly the account, they are all too happy to help so hopefully future projects will be quicker.

All the best, keep the updates coming.
Nicholas

Offline Air

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Re: Air Loudpeakers
« Reply #217 on: September 06, 2017, 12:20:04 PM »
Hello Stefan,

Really appreciating and respecting your commitment to quality on your project, i love it.

Regarding your engineering suppliers slow service for prototyping, in my engineering experience (not DIY) once you have built the relationship and more importantly the account, they are all too happy to help so hopefully future projects will be quicker.

All the best, keep the updates coming.
Nicholas

Thanks, Nicholas,
Encouragement is valued.

There are many good products abound and just another "me too" or commodity speaker won't cut it for us. We are fortunate that we can take this approach. We have some sponsorship from people who buy into our vision and we are not dependant on the project to pay the bills. It doesn't mean we don't understand the commercial realities. We are fanatical about every detail and often don't make our lives easier. Despite our frustrations, at times we do find lots of enjoyment in the process. We have learned a hell of a lot as well, about design, materials, production, patience and collaboration for example. Also to be open and listen to specialists in their respective fields, even though they might not be audio enthusiasts or speaker builders/designers. Often their contribution is very valuable.

The proof will be in the pudding but as I often found in my strategy development for organisations, the outcomes are the results of a meticulous attention to the process.

Tomorrow I will spend the day with Alex in Cape Town in a workshop about the detail of the assembly and finishing process, and maybe visit some of our suppliers. High on our agenda will be the finalisation of the mid sub enclosure's design. We have taken our idea of a post or 2 ago to the next level I believe. Hopefully, I will have some drawings of the final design ready to update those that are interested in our efforts.

Thanks again to all who are interested and show support. I am very much aware of the cynism that is out there. South Africans often have a love hate relationship with start ups or new kids on the block. Not only in our hobby but in many fields. So support is not taken for granted, not at all.