House jam-inspired backpack-sized 1x6" cabinet experiment

[cbd]

Years ago I built a 2x6" cabinet with a pair of Faital 6FE100s, exactly the size of my largest pannier bag so I could cycle to gigs with it. It turned out, mostly by accident, to be a success, and more recently I've been using it a bunch for double bass gigs. However at ~8kg or so it's still quite a lot of stuff to carry alongside a big bass, and I'm often playing drumless so I never turn it up past halfway anyway.

 

So after stumbling across @Phil Starr's micro cab design I thought I'd have a go at that to see if I could reduce the schlep even more - ideally for these gigs I could wheel the double bass in front of me with a normal-looking backpack with a cab in.

 

However I've had to modify the design slightly as not many bags are actually cuboid shaped. Here's what I've got so far after a trip to Huws Gray for some of their 9mm poplar ply and a day in the garage:

 

Next step - a baffle.

[Hellzero]

Following with interest.

[pete.young]

12 hours ago, cbd said:

Years ago I built a 2x6" cabinet with a pair of Faital 6FE100s, exactly the size of my largest pannier bag so I could cycle to gigs with it. It turned out, mostly by accident, to be a success, and more recently I've been using it a bunch for double bass gigs.

 

 

You cycle to double bass gigs?  I use a golf bag trolley to wheel mine around and was thinking about modifying it so that it could attach to the seat post with a Tagalong-style joint. That's a build thread I'd like to see!

[cbd]

52 minutes ago, pete.young said:

 

You cycle to double bass gigs?  I use a golf bag trolley to wheel mine around and was thinking about modifying it so that it could attach to the seat post with a Tagalong-style joint. That's a build thread I'd like to see!

Ah sadly my wife has forbidden that! Although I reckon some kind of trailer must be possible - I borrowed a friend's MIG welder for another project and it's given me all sorts of ideas...

 

I built the 2x6 for electric bass originally, and when I started playing upright more seriously a couple of years ago it's come in handy, being lighter than a full size cab and not super subby which I don't need for upright.

[cbd]

Baffle cut out, and some ports added. I had some 40mm drain pipe left over from doing up my kitchen so I wanted to try and use those instead of buying a whole new 2.5m of guttering as used in the micro house jam.

I've put the ports in the side rather than in the baffle. This is because I've bought another Faital 6FE100 as well as the Fane 6-100 and I'd like to be able to swap them out to compare. The issue here being that according to WinISD, the Faital needs much longer ports, so they wouldn't fit if I put them in the baffle!

[cbd]

I had a little play around with both speakers, trying out different port lengths as well. Some things I noticed:

- I actually tried both speakers _without_ ports at all first. Super interesting - the Faital sounds quite bad in such a tiny unported box, but at least there's some bass coming out. The Fane 6-100 sounded _terrible_ in an unported box - imagine trying to play through one of those 5w guitar amps that come free with the guitar...

 

- The difference after adding ports is insane - it seems completely impossible that drilling a hole and adding some old drainpipe would suddenly make it sound like a bass amp, but it actually works!

 

- I played both speakers with upright and electric. The Fane has a really nice top end, especially with a P-bass. As promised in the House Jam Micro Cab thread, it has much more low end than you'd expect. But I think the Faital is slightly more full at the very lowest frequencies, and seems to take away some of the nasally-ness of the double bass piezo pickup.

 

On both though there's an unusable amount of port noise. It's less bad with my BAM200, which seems to have a decent amount of high pass filtering going on, but with my GK MB200 it's pretty intolerable even for low volume noodling unless I use an HPF pedal or take most of the bass EQ out.

 

That's not a criticism of Phil's design though - for starters I think my cab has ended up being slightly smaller, more like 8.5L internally rather than 10 - plus I was being lazy and used the wrong diameter pipe for the ports, which means I've got less cross-sectional area than if I was using 68mm downpipe.

 

So next I'm going to fill in my old port holes and get some downpipe from screwfix.

[PaulThePlug]

Kick Backs... so sensible

What sort of Watt?

[cbd]

Both speakers I'm trying have ~100W average power handling. I'm planning to use this mostly with my TC BAM200 which claims to be 200W - but that's probably ambitious and into 4 ohms, so is probably unlikely to blow up the speaker

[PinkMohawk]

On 16/12/2024 at 21:53, cbd said:

I had a little play around with both speakers, trying out different port lengths as well. Some things I noticed:

- I actually tried both speakers _without_ ports at all first. Super interesting - the Faital sounds quite bad in such a tiny unported box, but at least there's some bass coming out. The Fane 6-100 sounded _terrible_ in an unported box - imagine trying to play through one of those 5w guitar amps that come free with the guitar...

 

- The difference after adding ports is insane - it seems completely impossible that drilling a hole and adding some old drainpipe would suddenly make it sound like a bass amp, but it actually works!

 

- I played both speakers with upright and electric. The Fane has a really nice top end, especially with a P-bass. As promised in the House Jam Micro Cab thread, it has much more low end than you'd expect. But I think the Faital is slightly more full at the very lowest frequencies, and seems to take away some of the nasally-ness of the double bass piezo pickup.

 

On both though there's an unusable amount of port noise. It's less bad with my BAM200, which seems to have a decent amount of high pass filtering going on, but with my GK MB200 it's pretty intolerable even for low volume noodling unless I use an HPF pedal or take most of the bass EQ out.

 

That's not a criticism of Phil's design though - for starters I think my cab has ended up being slightly smaller, more like 8.5L internally rather than 10 - plus I was being lazy and used the wrong diameter pipe for the ports, which means I've got less cross-sectional area than if I was using 68mm downpipe.

 

So next I'm going to fill in my old port holes and get some downpipe from screwfix.

Air flow is restricted on sharp edges, might be worth getting flares on the ends of the ports to help cut down some of that noise. 

[JohnH89]

I agree about the ports . Have a look here ...

https://www.bluearan.co.uk/index.php?browsemode=category&category=Hardware&masthead=Case_!amp!_Speaker_Parts&subheadnew=Tuning_Ports

Not going to break the bank and I have used these on a few builds without any problems .

[Phil Starr]

On 16/12/2024 at 21:53, cbd said:

 

On both though there's an unusable amount of port noise. I

 

On 16/12/2024 at 22:01, cbd said:

TC BAM200 which claims to be 200W

Even the 68mm port is a bit on the small side. 75mm would be better. I use drainpipe because it's easy to get hold of and you can get hole saws to cut a 68mm hole. It's part of the easy build philosophy behind my BassChat designs and I think I mentioned this somewhere in the text. We did specify the Blue Aran ports early on but availability was so patchy people were pausing their builds so I went back to drainpipe.

 

The micro amps are 130W into 8 ohms.

[cbd]

9 hours ago, PinkMohawk said:

Air flow is restricted on sharp edges, might be worth getting flares on the ends of the ports to help cut down some of that noise. 

Good idea, I've got a chamfer bit so I can hopefully round over the edge of the drain pipe port once I've got the 68mm pipe in.

[cbd]

5 hours ago, Phil Starr said:

 

Even the 68mm port is a bit on the small side. 75mm would be better. I use drainpipe because it's easy to get hold of and you can get hole saws to cut a 68mm hole. It's part of the easy build philosophy behind my BassChat designs and I think I mentioned this somewhere in the text. We did specify the Blue Aran ports early on but availability was so patchy people were pausing their builds so I went back to drainpipe.

 

The micro amps are 130W into 8 ohms.

The local screwfix has sorted me out with 2.5m of guttering high performance acoustic port material - hopefully that'll do the trick. I don't think I could go much wider with this design unfortunately - with 68mm I can just about tune it to 60Hz with the 6FE100 with a 27cm long tube, any wider and the port would have to be longer than the box (about 32cm long). Obviously the Faital would work just fine as at 87Hz tuning it doesn't need such a long port.

[cbd]

Seamless plugging of the old port hole - cut out a circle approximately the right size with a different hole saw then JB-welded in place (epoxy being much better at filling the enormous gaps my terrible carpentry left):

 

Looks better after some sanding:

 

Cutting a new bigger hole with a 68mm hole saw. Had to clamp on another bit of ply for support as there was a massive hole just where I wanted to put the drill bit...

 

Massive port for the 6FE100 installed. Hopefully under a load of tuff-cab no-one will ever know I didn't design it this way from the start:

[SpondonBassed]

On 18/12/2024 at 15:25, cbd said:

my terrible carpentry

 

Don't sell yourself short.  It looks fine to me.  Unless you are a proper Joiner that is, in which case...

Edited Thursday at 15:30 by SpondonBassed

[cbd]

1 hour ago, SpondonBassed said:

Unless you are a proper Joiner that is, in which case...

Ha thanks - fortunately not! Music is my hobby-gone-way-too-far that people for some reason pay me for, which means I can treat fettling around like this as a proper hobby, where I can get away with stuff like this without worrying about being judged too much...

[SpondonBassed]

4 minutes ago, cbd said:

Ha thanks - fortunately not! Music is my hobby-gone-way-too-far that people for some reason pay me for, which means I can treat fettling around like this as a proper hobby, where I can get away with stuff like this without worrying about being judged too much...

 

Living the life eh?  Good on yer.

[cbd]

Port noise is much better with the 68mm downpipe. After swapping between the two drivers, I've decided to go with the 6FE100. It does require an enormous port, which presumably takes away from already-limited 8.5L internal volume, but somehow it still works. There's not loads in it between the two, but the 6FE100 sounds a bit fuller on the lower strings (even works with a low B) and is a bit lighter.

 

Having made that decision I've glued the port in and rounded the edge over with the router, which takes the port noise down to close to inaudible.

 

Unfortunately it does mean cutting a new baffle, as the 6FE100 is a 6-hole mount and I'd put 4 T-nuts in the baffle for the Fane 6-100.

 

I did the first one with a jigsaw but it came out a bit wobbly so I thought I'd go fancy and use the router and a jig:

 

After getting most of the way through the board I cut through close to the line with a jig saw and used a flush trim bit to clean it up: