A DIY lighter cabinet? I'd like one made!

[Dood]

I'm just floating an idea here. I love the sound of my Hartke 4.5XL cabinet. It does however weigh a ton in comparison to modern Neo kit.

I was wondering on the viability of having someone make a clone cabinet out of say 15mm Poplar Ply (with additional bracing should it need it) then drop all the existing hardware, speakers and grill in to the new box. I feel sure that there would be a substantial weight saving, given the standard shell is made of 18mm birch ply. (lined with lead it seems).

Standard cabinet weight 45kg. I could also replace the carpet covering with some of that paint of finish so my cat doesn't destroy the cabinet finish too!

Thoughts?

[Mr. Foxen]

If you keep the box volume and tuning, could probably rearrange it beneficially for dispersion too. Is it lined and such? Part of the colour might come from being unlined and having walls that distance from the speaker, if it is all lined, that is less of an issue to a different shape.

[paul_5]

Is it still considered DIY if you're having one made? thought not [/pedantry]

[Dood]

Hey!

It is lined with the usually wading 'stuff' - seems quite ample in there too. I think I'll pop one of the drivers out at some point for a snout round to see what's what. On a bit of a tangent, I know the 410XL cabinet (standard weight 32Kg) uses the same drivers, so I was even tempted to clone that box and drop the 4.5 drivers in. but I think the 4.5XL has a deeper tone to it.

I love the idea of rearranging the drivers to aid dispersion - that sounds like fun - The reason for keeping the same dimensions was to make fitting existing hardware, such as the grill straight on without having to customise or purchase new. Keeping costs down in the long run.

[Dood]

[quote name='paul_5' timestamp='1344971799' post='1771908']
Is it still considered DIY if you're having one made? thought not [/pedantry]
[/quote]

heh heh, I guess not, but it draws the DIYers in to have a looksie!

[paul_5]

ooh, I see what you did there - very canny!


I can see I shall have to keep my eye on you...

[Dood]

[quote name='paul_5' timestamp='1344972066' post='1771918']
ooh, I see what you did there - very canny!


I can see I shall have to keep my eye on you...
[/quote]

Whilst you were typing, your cuppa just went missing. Nomm!

[paul_5]

B'stard! I'd only had two sips...

[Dood]

In all seriousness though, is it pretty easy to get hold of the lightweight ply that the 'boutique cab' builders favour?

[Balcro]

Hi Dood,


http://www.avonply.co.uk/Stocks.aspx

2500mm x 1220 x 15. -- £52.73 + Vat.

Balcro

[Dood]

Thank you Balcro!!

Dooooood

[Happy Jack]

[url="http://www.ebay.com/itm/48-Zippo-Lighter-Display-Rack-Case-Cabinet-Wood-Door-/370270683081"]http://www.ebay.com/itm/48-Zippo-Lighter-Display-Rack-Case-Cabinet-Wood-Door-/370270683081[/url]

Here's a lighter cabinet.

Not sure it's DIY though.

[Dood]

[quote name='Happy Jack' timestamp='1345034642' post='1772631']
[url="http://www.ebay.com/itm/48-Zippo-Lighter-Display-Rack-Case-Cabinet-Wood-Door-/370270683081"]http://www.ebay.com/...r-/370270683081[/url]

Here's a lighter cabinet.

Not sure it's DIY though.
[/quote]

"DUDE!! Your playing was on FIRE tonight!!"

[Mr. Foxen]

[quote name='Balcro' timestamp='1345031715' post='1772544']
Hi Dood,


[url="http://www.avonply.co.uk/Stocks.aspx"]http://www.avonply.co.uk/Stocks.aspx[/url]

2500mm x 1220 x 15. -- £52.73 + Vat.

Balcro
[/quote]

Avon ply are great to deal with, sorted all the wood for the octobass, and CNC cut it.

[Dood]

They'll CNC cut for me too? Now that's going to make things very helpful! Sadly, I don't own a tool shed or the necessary cutting tools. Construction of the parts would be a much easier job for me!

[paul_5]

no toolshed? where do you keep your erm, you know....[i]things[/i]?

[GarethFlatlands]

[quote name='paul_5' timestamp='1345049084' post='1772886']
no toolshed? where do you keep your erm, you know.... grumble mags?
[/quote]

Fixed.

[Dood]

[quote name='paul_5' timestamp='1345049084' post='1772886']
no toolshed? where do you keep your erm, you know....[i]things[/i]?
[/quote]
[quote name='GarethFlatlands' timestamp='1345049687' post='1772901']
Fixed.
[/quote]

Ha ha ha ha - I keep [i]my[/i] 'things' all over [i]my[/i] house. I'm, not confined to keeping things in one room.

Grumble mags? Nah, I have a hotty for a girlfriend

[Mr. Foxen]

[quote name='dood' timestamp='1345039610' post='1772732']
They'll CNC cut for me too? Now that's going to make things very helpful! Sadly, I don't own a tool shed or the necessary cutting tools. Construction of the parts would be a much easier job for me!
[/quote]

CNC funny shapes and it costs, you have to sort them with some sort of plan, obviously octobass was weird shapes, so we made a proper CAD file for it. Squares they can do the trad way. They've done lots of speaker cabs so can sort that easy, cutting big round holes for speakers.

[Dood]

Diamond, just what I wanted to hear. I need to do a cutting sheet with the details for them and then I'll ask for a quote. I think this could well be a 'do-er' as they say! An interesting project, but at the same time a way to test a theory. Can I make my favourite cabinet even better?

[stevie]

An interesting project. Bear in mind though that you already have the ideal cabinet material in 3/4" plywood and are unlikely to maintain the same quality of sound if you go lighter. Unless a lightweight cabinet is a 'must', the best solution to transporting the cab would be castors or a trolley.

(Now cue all those with cabs made of 1/8" balsa wood telling me I'm wrong. )

If you go ahead, I hope you'll report back with your findings.

Edited August 16, 2012 by stevie

[Dood]

Cheers Stevie! I'm expecting a change in tone, but that could be said of the likes of Tecamp / Barefaced / [insert lightweight cab manufacturer] if they'd opted to included an 18mm birch ply cabinet version too. Yup, it's a weight saving decision solely.

Having looked at the 4.5xl vs the 410xl, even a change in cabinet dimensions but using the same materials saves aroiund 13kg! (both cabs use the same 10" drivers). I could even look at doing a lightweight version of the 410 xl; yes i think it couod suffer tonally, but i hope it'd still maintain the Hartke Alu character but at a substantial weight saving. It'd also be a fun project.

It's funny, i was thinking - we spend so much time effing with our basses with new pickups, hardware and construction as well as modding amps - why not mess with a cabinet or two as well!

I think if i get started, i'll merge these posts in to a build diary. Oh and i might just stick wheels on the cab too for a laugh!

[Phil Starr]

Stevie's comment got me thinking, I'm an old fashioned boy and my cabs tend to be made of 18mm birch ply or even high density Chipboard, a much underrated material for cabs.

The sound transmitted by the panels of a cab is moderately difficult to predict but will depend upon the mass of the panel, the flexibility, the dimensions and any damping. In the end a high mass will have a lower resonance and move less for the same applied energy so a 3/4" panel will 'sound' less than a 1/2" panel. (I said I was old fashioned)

Birch ply has a density of about 690kg/m3 and Poplar about 520kg/m3.

If you drop from 18mm to 15mm with birch ply and your cab has about 2m2 of board in it you'll save about 4.2kg if you go as low as 12mm then it will be 8.3kg.

Swapping birch ply for poplar (18mm) will save you 3.4kg

I haven't checked the Young's modulus for the various plys (Basically how bendy they are) so I don't know which timber will be more resonant. I might look that up too.

Using thinner panels would mean you need to add some bracing and this would add more weight to the cab so in practice you wouldn't get the full weight saving unless you were happy to live with a more resonant cab. Cab resonance isn't always a bad thing however; it all adds to the 'sound' of your cab which will change subtly with the use of different panel materials and damping. I think the character of the Hartke drivers would still be strongly evident though.

[charic]

Remember, lightweight cabs are just helping the thieves

I actually NEVER worried about my Line6 as it weight in at 96lb iirc. Any poor git tried to nick that they'd be in for a shock and i'd probably find it less than 100m down the road

[alexclaber]

[quote name='charic' timestamp='1345189907' post='1774655']
Remember, lightweight cabs are just helping the thieves

I actually NEVER worried about my Line6 as it weight in at 96lb iirc. Any poor git tried to nick that they'd be in for a shock and i'd probably find it less than 100m down the road [/quote]

I felt the same about my trusty Peavey combo!

Phil, if you maintain (or increase) stiffness through bracing, whilst lowering mass, you raise the resonance of the panels to the point that they are no longer excited by pressure but instead excited by the backwave, and the backwave and the resulting panel emittance can be damped effectively, unlike pressure changes which you don't want to damp (as they excite the port). In the process you also reduce the backwave reflection which exits through the cone. Personally I consider panel resonance in a loudspeaker a horrible thing unless it's being used to cancel unwanted energy - the last thing I'd want is significant acoustic energy radiating from a panel, with particular consideration being given to how it screws up transient response.