Kairos Speaker Build

Discussion in 'Audio Visual' started by Eclipsor, Sep 10, 2018.

  1. OP
    OP
    Eclipsor

    Eclipsor Member

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    Happy new year all! Well, this has now officially extended from a winter project to a 2018 project to just a project... However, with some annual leave forced on me with an office closure this week I've done a lot of work and reached a milestone with the speakers. The 2-way Kairos are finished! I'm very glad to have them back playing music. The temporary speakers I'd been running for a couple of months weren't really inspiring me.

    Side and top veneer applied, trimmed and sanded. You can see the J-Roller in the bottom right corner that I ordered after veneering the first panel in early Dec. I was worried about peeling back some grain by just using a rounded piece of ply to press it down.

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    Front chamfer veneer glued down. It was very fiddly and time consuming trimming all the edges around the front due to the angles. I ended up trimming all the veneer with a knife by hand.

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    All veneer trimmed and initial sanding with 240grit. I applied a solid sheet to the front and with a lot more fiddly and time consuming trimming with a scalpel trimmed out the driver holes.

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    I went to some effort to cascade the grain from the top onto the fronts

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    First coat of finish applied (it is still wet in the photo). I ended up using Whitle Waxes Evolution Hardwax Oil in satin. I was aiming to get a finish similar to using Danish oil, but was hoping for something that provided a bit more protection. This product is primarily intended for coating timber floors, so I'm hoping it does this. I wasn't after a very glossy finish, but I may have gone for the gloss if I had the time again, but overall I'm pretty happy with the result.

    For reference, my procedure was:
    - Final sand to 320grit
    - Clean and wipe down
    - Apply fairly thick coat with a foam brush
    - Sand lightly with 400grit to take off the grain lifted by the first coat
    - Clean and wipe down
    - Applied another 3 coats with a rag wiping down between each

    It will apparently take 8-10 days to fully cure and apparently I shouldn't lay carpet on top of it or walk on it before then. ;)

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    4 coats applied

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    Terminal holes redrilled and terminals fitted

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    I'll leave it hanging there for now. I've removed the terminal connectors for the driver and input terminal connections now and soldered direct. I've refitted the drivers and they're up and running. I'll take them outside later on for a proper photo shoot.
     
    Last edited: Jan 11, 2019
  2. DangerMaus

    DangerMaus Member

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    Looks great. How are you liking the sound after a while?
     
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  3. evilasdeath

    evilasdeath Member

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    looks sweet!
     
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  4. OP
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    Eclipsor

    Eclipsor Member

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    Just getting used to them again now. Overall I'm very happy with the sound. I think I'll be able to live with these for quite a while. I'll probably actively avoid listening to any others for a while so that I can live in my little bubble that these are the best speakers ever made for a while at least. :p But I would like to think that I'd be hard pressed improving on them for less than $2-$3k (at least at new prices). That said, I'm not under any illusions that building my own was a very low budget way of doing things. Especially being my first pair. Now that I have the baseline tools the second set might be a much better bang for buck, whenever that happens...
     
  5. OP
    OP
    Eclipsor

    Eclipsor Member

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    Some camera shots:

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  6. Hi-end Head

    Hi-end Head Member

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    While the sound might be very exceptable now. Give it a few months when there "run in" and the sound will improve very slowly over time.
    Your next challenge will be a quality integrated amp, to really make them shine
     
  7. OP
    OP
    Eclipsor

    Eclipsor Member

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    Yes, the idea of an amp has been niggling away at me for a little bit now.
     
  8. Hi-end Head

    Hi-end Head Member

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    The problem is most people think that the only things available with-in there price range is an AVR. If you believe the likes of Gerry and JB, Who only seem to stock AVR, simply because of all the features, we must all have. 90% of them we never use. The other problem is the AVR was never designed for Audio, That together with the over inflated spec's about power outputs.

    You really don't need to spend a fortune or a Kidney, If you still have one left., on a quality integrated, there are meany opportunities to acquire used or demo stock. An example this was a while back when Vincent changed importers, and main retailers like Eastwood, where selling quality gear at half the retail price simply to clear stock.

    An example of what's available is shown here https://www.aussieaudiomart.com/classifieds/18-integrated-amplifiers/ with prices to suit most budgets. While I'm not suggesting you spend mega dollars, believe me the day will come when you will consider something above entry level. Simply play the waiting game, an something will come along to suit your requirements and price
     
  9. OP
    OP
    Eclipsor

    Eclipsor Member

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    I've got a Cambridge 2-channel integrated currently which I'm pretty happy with. I'm mainly interested in the idea of making a DIY amp now.
     
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  10. Hi-end Head

    Hi-end Head Member

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    Cambridge make some fine products, Unfortunately there UHD player has gone the way of Oppo, and has ceased production.
    Many people intending to build there own amp's go for a Valve design, probable due to the fact that printed circuit boards are not readily available together with the many small components .

    Valve designs normally have point to point wiring, which simplify's construction. One of the better design sites available, [ even though little known ] is Pat Turners site http://turneraudio.com.au/
    Years ago Pat's designs where legendary in both build quality and performance. It's said that people that own his amps, are buried with them. I have never seen a used PT amp offered for sale His site offers spec's and wiring plans for the home builder

    Another manufacturer to offer pre-assembled components is "Holton" HTTPS://holtonprecisionaudio.com/ While they are very "HighEnd" with there products they do offer a range of components for the home DIY builder https://holtonprecisionaudio.com/collections/diy-audio-products
     
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  11. MUTMAN

    MUTMAN Member

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    so they're ready to have the carpet laid on them now ?

    nice work on lining up the veneer too, great effort all round.
    If you're going DIY on the amp, have a look at DIYaudio.com, or just buy a nice clean example of a sansui alpha AU-907 ;)
     
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  12. DangerMaus

    DangerMaus Member

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    You again?
    It's been a few months since he started breaking them in...
     
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  13. OP
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    Eclipsor

    Eclipsor Member

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    Thanks. I'll check out those sites.

    Haha yep. Thanks. I've had a bit of a look around the diyaudio amp section. All a bit overwhelming. Early days though. Always got half an eye on gumtree. ;) I tried to buy a Yamaha A-1020 that had issues the other day as I thought doing up an amp might be a good place to start rather than from scratch, but it was gone within a few hours.
     
  14. MUTMAN

    MUTMAN Member

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    Power amps go relatively cheap (keep half an eye on SNA too) and you could build a passive pre yourself.
    Just spend up on the potentiometer ;)
     
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  15. Sarsippius

    Sarsippius Member

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    The speakers have come up nicely, I don't think the look of the angled back baffle really does it for me in general but you've done a good job. :thumbup:
     
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  16. OP
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    Eclipsor

    Eclipsor Member

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    Thanks. Yeah, fair enough. I don't mind it, but it probably wasn't my first choice for aesthetics either. The sloped baffle provides time alignment of the drivers though, so it is a functional part of the design at least.
     
  17. Hi-end Head

    Hi-end Head Member

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    That's very debatable, when you consider the fact that both of your speakers [drivers] are on the same vertical plan, regardless of the angle, in short you get what you get.

    Time alignment is somewhat of a debatable subject, Large high-end designers [Wilson, YG, etc] will waffle on about "Time Alignment" and just how beneficial it can be.

    High end reviewers will write large reviews on the subject, of just how beneficial it it. Together with detailed graphs, and measurements. Can a difference be heard, in most cases it can not. But that feature does in part justify the high cost of the speaker.

    BUT most of there designs, consist of separate independent baffles, which can and do change there angle of alignment, So that at a distance to be determined by the user will allow both speaker volumes to interact and duplicate the sound output at precisely the same time, and in the same space // place,
     
  18. OP
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    Eclipsor

    Eclipsor Member

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    The drivers are on the same vertical plane if you are sitting about 4m in the air above them. However, if you're sitting in front of them the tweeter is certainly positioned behind the mid/woofer.

    I'm not going to pretend to be an expert in speaker design, but the design process for these speakers is discussed in great detail in Jeff Bagby's white paper here if you are interested.

    He goes through his design process when dealing with issues relating to vertical and horizontal off-axis response, the issue of the drivers being off-axis by default due to the sloped baffle and many others. The exceptionally linear phase and time domain response of this design is one of its defining features.

    Cost/benefit discussion points like this are moot for DIY because it doesn't add to the cost. Either the designer has the skills and thinks it is worthwhile to design it in, and the builder can be bothered/has the tools/time to make it or they don't. Jeff has even designed a version without the sloped baffle called the Adelphos but the kit for this actually costs more because the crossover has more parts.

    With all that said though. No, I can't say whether I can hear the difference or not as I don't have any other comparable quality speakers to compare to, or have listened to many others over the years. So yes, potentially it was a complete waste of time. ;) Plenty of others that have built them do attribute some of the quality of the output to these design attributes though.
     
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  19. Hi-end Head

    Hi-end Head Member

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    Far from it, you should be commended for what you have achieved, and for what you have learned on your journey, Just remember you would not have thought 6 months ago, that what you have done was possible.
    As I said before "Time Alignment" was a contentious issue, Just about every reviewer has a different opinion, on the subject. It could be argued that while you have a sloping baffle, The mid-range while larger and pushing more air, should be placed at the top of the baffle, with the Tweeter below it, and closer to the designated point, due to the fact that the sound has to travel a shorter distance. But while the tweeter is at the top of the slope it needs to travel further, and as it produces a weaker signal.
    Of cause it goes without saying that the complete reverse is also correct, as I said it's a contentious issue, which will remain unsolved, as spec's and measurements are gathered in complete secret, and are undeniable unable to be proved or discounted. My own personal opinion is most of the so-called data on Time Alignment is complete "snake oil" and completely unproven, and the sound produced no different from a standard baffle design.
     
  20. DangerMaus

    DangerMaus Member

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    Hahahaha. What?
     
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