Poll

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

Small Bookshelf-below R20K
11 (9%)
Standmount Between R20-R50K
9 (7.4%)
Standmount between R50k-R100k
2 (1.6%)
Floorstander below R20k
28 (23%)
Floorstander between R20k-R50k
35 (28.7%)
Floorstander between R50K and R100K
11 (9%)
Floorstander over R100k
13 (10.7%)
Planars or electrostatics (can incl  conventional bass drivers)
10 (8.2%)
Horns (primarily based on typology)
3 (2.5%)

Total Members Voted: 122

Author Topic: Air Loudpeakers  (Read 21854 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.

Offline Air

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Re: Air Loudpeakers
« Reply #218 on: September 25, 2017, 09:24:05 PM »
Hi guys here is a quick update on progress. After lots of thinking, head-scratching and few versions, here is the final mid compartment of the Vivace. I will leave it up you to try and get behind our thinking with this part.. :thinking:
The drawings have been sent to the machine shop to start with the machining of the mould. Will be a carbon fibre moulded compartment as mentioned previously.











and just to add perspective, this is how it will fit in the carcass with the torque rods visible as well.




Offline Atjan

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Re: Air Loudpeakers
« Reply #219 on: September 28, 2017, 03:48:41 AM »
Very nice! I like the curve that follows the cabinet shape. Are you going for a type of tapered tube effect? Would the mid not have been more effectively insulated from the woofer with a more conventional shelf type cabinet?

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Offline Air

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Re: Air Loudpeakers
« Reply #220 on: September 28, 2017, 01:50:20 PM »
HI Atjan
Thanks for your continued interest and engagement with the project.

Let me start by answering your last question first. If I understand your question correctly you are asking whether 2 separated enclosures, like the Wilson Watt and puppies or like the B&W 801 etc would not provide more isolation than our current approach. I think such an approach is very effective, however, I believe from an industrial design perspective perhaps not so great. The B&W 800's are in my opinion one of the best industrial design exercises. They nailed it whilst Wilson and many others could not achieve the same elegance and refinement. I think the form factor of the Vivace would be compromised if we have gone that route- a smaller cab on a bass bin.

Let's go through our logic. There are basically 3 subsystems in our design. The light carbon fibre carcass, the high mass baffle and top and bottom aluminium parts that are coupled and torqued with tension rods, and then the mid carbon fibre enclosure. These parts can either be directly coupled or decoupled with seals etc. The carcass will float as it is decoupled from rest of high mass parts. The bass driver will be decoupled from the baffle with a gasket, ie it will seal but the driver will be loosely bolted on the baffle. The mid and tweeter will be coupled to the baffle and will use mass as a way to manage the energy when in motion. The mid enclosure is attached to the baffle and doesn't  touch the carcass. So effectively it is 100% isolated from the chassis vibration of the bass driver(decoupled) and the energy of the back-wave of the bass driver( carcass and mid enclosure as not in contact with each other. A high mass approach is good for the mids, and a low mass enclosure where the vibrations can easily be damped because of the light but rigid approach or pushed higher up in the frequency range through bracing. In this approach, we echo B&W view of the mid enclosure and Vivids approach with the decoupling of the bass units(obviously not their the push-pull cancellation approach) Magico and Wilson Benesch are closest to our approach, especially with the moulded mid compartments of the newer models.

As for the design yes it is a taper tube/horn broadly speaking, an inverse horn if your wish, once again like Vivid's tapered midsection, but we paid close attention to make it as asymmetrical as possible. It is also much bigger as our mid will cover a wider frequency spectrum, Vivid's mids are typically from 900Hz to 4Khz.  From the front, it is narrower at the bottom than on the top if you look at it carefully. We also included flares in the side walls, that provides more breathing space right behind and to the sides of the mid driver and that (theoretically) assist with managing the back-wave effect through preventing a direct bounce back through the cone and further diffraction. The design is also just cool in our opinion. I even said to Alex, it would be a cool small desktop speaker if it is finished to Mclaren .carbon fibre standards  :cool:

What we also, once again realise is whilst working on the port is how much a radius increase stiffness in most materials and especially in moulded carbon fibre. The difference in stiffness between a flat panel carbon and a curved one is significant. We also have the option to choose a different and slight softer core for the midsection that will provide more damping than the very stiff but slightly harder core of the carcass. If budget allows it and it can be absorbed in the final pricing we could mould with carbon nanotubes, but maybe that is one step too far and would be extremely expensive.

So much for theory and design principles.. like many on the forum would say.. the proof is in the pudding- sound of final product


« Last Edit: September 28, 2017, 01:58:56 PM by Air »

Offline Atjan

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Re: Air Loudpeakers
« Reply #221 on: October 09, 2017, 02:49:20 AM »
Thanks for sharing all that! Do you have a new completion date yet?
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Offline Air

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Re: Air Loudpeakers
« Reply #222 on: October 23, 2017, 08:29:54 AM »
Hi Atjan, slow reply as I was travelling quite a bit in last month with trips to Kenya, Tanzania and Uganda, so clocking up some miles ;)
I was also waiting to get feedback from our the advanced composite materials supplier on the scheduling of the midsection.
Both the final wood parts as well as the midsection delivery date are scheduled for the 2nd week of November. If there are no hiccups of rework necessary then we are in a strong position to assemble the 1st pair in November. Alex and I are both can't believe that it takes so long, but outsourcing development work to 3 major industries, composite structures, wood bending and aluminium manufacturing make for a lengthy process. We have learned a few lessons in the process and will tackle the next design, the VocÚ, with a slightly different approach to see if we can cut down time with the development process.
cheers
Stefan

Offline Nirvana

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Re: Air Loudpeakers
« Reply #223 on: October 23, 2017, 10:58:20 AM »
Like Atjan,following this with great interest,really hope all goes according to plan re a launch before year end.

Must be frustrating and testing,with wanting to see and hear the final product,but also making sure it's as good as it can get,before opening night...  :2thumbs:
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Offline Atjan

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Re: Air Loudpeakers
« Reply #224 on: October 30, 2017, 03:15:50 AM »
All the best with your efforts towards year-end. In my experience it is very hard to get anyone in industry to provide service to 'non-core' customers in November. December and January you may as well consider non-trading months.
It's only hifi people....