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Speakers: MUN17-3W

I think I've just about decided on what to do cabinet-wise. There were some grand visions of exotic materials sprinkled with gold dust but in reality my skills in this area are sorely lacking and I suspect I would make a complete hash of it. I've narrowed it down to a few more basic options...

1. Build the whole cabinet out of valchromat, veneer the main body of the cabinet and leave the baffle black

2. Build the cabinets in ply, veneer all round and fit some valchromat baffles to the front. Kind of like a poor man's ATC floor stander

From some searches online it looks like decent plywood is now so expensive that it doesn't make much difference if you build the whole thing in either material. Is there a consensus on which is 'better'? I imagine valchromat is probably easier to veneer over.
 
I built mind with a combination of MDF and marine ply, ply is harder to work with so depends on your tools
and skill.I use a layered and braced combination, plywood core with MDF outer skins, veneered on sides and
painted black MDF baffles.Took me ages to finish so depends on how much time you want to spend and finish
quality you want.
Given the cost and quality of your drivers I wouldn't skimp on materials or tools to build them, and don't rush
it's easy to get carried away and end up with a dog's dinner.
 
I wouldn't stress too much about the material. You could build the bass section out of mdf and the rest out of ply.

My latest build used ordinary plywood (which I got free). The occasional void is not a problem, just fill with polyfilla and sand flat before veneering.
I actually went for a sandwich construction.
https://pinkfishmedia.net/forum/threads/discocat-speaker-design.283558/

I will eventually get round to accelerometer testing versus my previous boxes, which are MDF/Chipboard/Ply. I don't expect the new ones to be worse... judging from the sound quality.
 
Thanks gents... Your construction looks excellent S-man, I'd be happy with a similar quality here!

Spot on advice regarding not rushing into the build. I'm very guilty of doing this, every time. I never learn.

Troels sent through the b.o.m this week so I quickly priced up the components. I may be naive but I was expecting to pay a few hundred pounds on the crossovers here. My basket is sitting at £1,500!

I'm sure the quality is excellent however the cost does make me consider using the hypex x-over option for the midbass as well, leaving solely the tweeters as passive. I could always mount the rear of the mid cabinet in a removable fashion to facilitate a swap to passive later on so I can hear them how they were intended.

I'm wary of driving the tweeters actively in case something goes pop and I'm left with some lovely paperweights.
 
The choice of crossover components from Troels are based on the quality of the drive units.
If you go to the humblehifi website capacitor test
https://www.humblehomemadehifi.com/Cap.html
you can get an idea of the sound quality versus cost equation for capacitors.

If you don't want to start with the "boutique" components choose a "normal" level of components, you can always upgrade later.

A rough rule of thumb for self build speakers is that the crossovers cost nearly as much as the drive units. Normal 2 way woofer and tweeter costs about 100€ per speaker, I would pay about the same for a standard 2nd order low pass, woofer, and 3rd order high pass, tweeter.
 
It’s worth remembering that Troels is sponsored by Scan-Speak. This may also be true for pricey XO parts.

I am not overly convinced that XO parts need to be expensive. My latest XO for the DiscoCATs uses very cheap components and sounds very good. It’s hard to imagine the earlier XOs sounding that good even with golden virgin oil caps etc.
I will do some comparisons with better parts when the values are fixed, but I’m not expecting huge improvements when I swap eg the cheapest ebay series cap on the tweeter to something fancier.

if you want to go all-active you could use a large value single cap in series with the tweeter, to provide dc protection.
 
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S-Man said:
I am not overly convinced that XO parts need to be expensive. My latest XO for the DiscoCATs uses very cheap components and sounds very good. It’s hard to imagine the earlier XOs sounding that good even with golden virgin oil caps etc.
I will do some comparisons with better parts when the values are fixed, but I’m not expecting huge improvements when I swap eg the cheapest ebay series cap on the tweeter to something fancier.
Click to expand...
I personally think this is the key for all these areas where there is a great deal of discussion (cables, xo-over parts, opamp-rolling in electronics etc.) that you need a baseline to compare against in order for it to make any sense. You can of course pick the most expensive parts from the beginning, but experimenting to then try and make your speaker sound worse with cheaper parts seems a bit backwards...

I would say that logically the type and quality of transducers (drivers) and the x-over topology including x-over frequencies will have a much bigger impact than e.g. two different capacitors of identical value. Therefore, building a reasonable x-over circuit with "fit-for-purpose" parts and if you want to experiment then selectively replace parts and listen if you can hear a difference once everything else is settled.
 
@James extolled the virtues of Superior Z caps for anything in series and these are highly rated in the link provided by @cpg above:
"The Jantzen Audio Superior Z-Cap is a no-brainer if you are looking for a capacitor that performs well in all area's and is very well balanced. One of my personal allround favourites :)". You can get away with 'lesser' parts that are in parallel or shunting to 0V. Cricklewood electronics do Ansar caps to big values (weirdly only on ebay, not via the site?) Here https://www.ebay.co.uk/itm/26485395...d=link&campid=5338728743&toolid=20001&mkevt=1 and these are good vfm
 
This site contains affiliate links for which pink fish media may be compensated.
It's worth shelling out for the caps in series with the mid range, either Mundorf supreme (my favourate) or the Jantzens mentioned above.Most of the music is in the mid range and our ears are most sensitive here.All the rest even the tweter cap can be basic polypropalenes to start with especially those to ground.
Not worth skimping on coils just get what he recomends.I
The Hype x plate amps are not cheap either these days and you will have to do a shed lot of work to get it going.Do you have measurement tools, microphone etc, the Hype x software is not easy to use in measurement mode and it needs
a compatible mic.
 
Interesting. And didn't realise Troels was sponsored by some of these companies - makes sense!

Regarding the hypex set up; he's provided a download for this based on activating the bass driver only. If I wanted to play about with a more active setup I'd be on my own, although the basic crossover points are published I believe.

The principle behind building a lower cost crossover to begin with makes sense however it's potentially further expense in the long run. Plan A is still to build it as per the standard build.
 
Makes sense especially with such high cost drivers, I found with my speakers his recommended tweeter dropping resisters
we're too bright for me so increased the value,worth buying some extra resisters of around 0.5ohm difference to find tune.
There is a similar design on his site (The Fusion) which uses the same mid, this has a number of passive and active
options which you could get inspiration from if you want to go in the active direction.
 
The drive units have arrived, thankfully unmolested by the delivery company. It'll be a while until they make any music but if aesthetics were any guarantee of quality I'd be very happy. They look great. The bass drivers are ridiculous. One of them alone weighs more than most pairs of speakers I've had.
 
After much to-ing and fro-ing I've ordered the cabinet materials. As my woodworking skills aren't up to much, and my garage is full of just about everything other than my tools, I've gone for one of those cut to size places online. I've used a place called 'cut my plastic' which funnily enough has a great selection of sheet wood, MDF and valchromat. This came to more than I wanted to pay but includes doing some fancy cuts and the driver holes for the woofers. I've not strayed too far from troels' design; just a slightly different build method using the same overall sizes.

Spend to date:
Speaker Plans : £90
Woofers: £1,147.90
Mids: £381.71
Tweeters: £984.35
Ply / valchromat: £469.61
Total: £3,073.57

I should point out I'm not tallying up the spend here to impress. I think it's important to record it both for myself and also for others to put a realistic value on these builds and compare them to commercially available offerings. These things will end up equal to or more than some very well thought of ATC options for example - it does open up some questions for me. Particularly as the resale value will be close to zero!
 
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Can anyone recommend any black self tapping screws / hex bolts to use here? If I've read the datasheets properly the hole dimensions are:

Tweeter: 4.5m hole; 8mm opening
Mid: 5.3mm hole; 10mm opening
Bass: 6.3mm hole; 11mm opening

The baffles will be around 30mm thick
 
I would use inserts like these https://modelfixings.co.uk/threaded_inserts.htm driven into the front panel from the back and then M4/M5/M6 hexhead/torxhead bolts to mount the respective drivers (also available from modelfixings in both black and stainless). A bit more work overall, but if you are building "serious" speakers IMHO it's worth it to ensure you can safely remove and refit drivers later on.

If you build with a removeable back panel so you have sufficient access to the rear of the drivers, you can also mount drivers with longer bolts through the panel and then simple use good-quality nuts/washers to secure them. Saves faffing about with the threaded inserts.

PS: Linking to modelfixings as I found them to be 100% reliable for years and years of buying fasteners. Unfortunately Brexit made them unviable for shipments to EU :(
 
Is there a dummies guide to using a router anywhere? I've never used one but suspect it would be a good investment...
 
This site contains affiliate links for which pink fish media may be compensated.
fraser. said:
Is there a dummies guide to using a router anywhere? I've never used one but suspect it would be a good investment...
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Have a look on utube, lots of stuff on there, get some mdf from a wood supplier they often have lots of scrap
pieces they will sell you cheap, use this to practice on first.
When you do progress to your proper stuff use shallow cuts don't try and do it in one shot.
I don't use t nuts just wood screws, I know it's fashionable to bolt drivers down tightly but you can distort chassis
quite easily especially the Scan tweeters, they only need to be tight enough to get a seal.Check out what Troels
Uses.
 
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