XF210 build in the UK

[Oxonjohn]

I'm going to cut the holes for the jack sockets next, but I have a couple of questions:

1. Rather than cut a hole and stick a jack plate on the back, I plan to route a circle in the upper back plywood thin enough to mount the jack. Is there any reason I shouldn't do this? It will be a little more difficult but I'm keen to make use of the router now I've got it, and if it goes wrong I should be able to just drill it out and revert to plan A.

2. I'm concerned about my plan for two jacks sockets. The importance of having airtight cabs is often emphasised, but if I have two jacks and only use one my cab won't be sealed as air can escape via the second jack. In fact, even one jack socket surely wouldn't provide an airtight seal? Are there such things as airtight jack sockets like there are for Speakons and XLRs?

Can anybody help me with these?

Thanks,

John

[LelandCrooks]

Airtight is not as critical on xf's.
I'd be concerned that you have enough ply to support plugging and unplugging the jacks. Back it up with another piece of ply inside. And that small a hole is tough to router.

[Oxonjohn]

Thanks Leland. I was going to route the hole using a top bearing bit and piece of scrap with a 1" hole in it as a guide. Guess I won't bother now and use a separate plate for the socket (as per the plans!).

John

[Tom Smit]

One could put a dummy 1/4" plug in the empty extra hole to close it off.

[Charles Jenkinson]

Boxing off behind each of the jack sockets (if they're both together one box would do it) and sealing the wire-through locations is an option.

[Oxonjohn]

Thanks Tom, but putting a dummy plug in the second socket will open the switch and isolate the drivers.

The boxing off idea seems sensible Charles, although Leland didn't seem to think that sealing was too much of a concern on an XF. I'll probably do it anyway as it can't do any harm and will be good practise for when I move on to other cabs. One of the reasons for doing the XF first was to check out my sealing skills on something where it wasn't quite so critical.

John

[Oxonjohn]

Yesterday I fixed in the baffles, probably the most important stage so far. Not the easiest job given that you have to stick several edges of each baffle in one operation - all four in the case of the second baffle.

I put adhesive on the carcass for most of the joints but put it on the baffle for the last edge as I was worried that I wouldn't get any glue between the baffle edge and the carcass otherwise (maybe I made my fit too tight). I found it quite difficult to fit the baffles without the adhesive from the last edge wiping off on the carcass before the panel was in place (see the bottom edge of the right hand baffle in the picture below). I've got a fair bit of excess adhesive to remove from some areas. Hopefully I had enough left in there to give good and airtight joints, but there is very little squeeze out evident on some of them. I'll probably end up adding some kind of sealant to make sure, and also to produce a nice fillet as these joints will be visible (I'll be using individual round grills for each speaker rather than a grill that covers the whole front - after all the work on the angled baffles I want people to be able to see them!).

Any recommendations for the type of sealant I should use - something that my Tuff Cab finish will adhere to?

John

[Charles Jenkinson]

I get the feeling that a slightly different technique for gluing that second baffle in place might be better: to glue up all edges of the baffle and insert it 'tilted' across the shortest diagonal, then rotate about the diagonal so the edges come into mating contact. It would require thinking about back support block locations, which are useful initially for setting/trimming the baffles, but would interfere on baffle installation.

I don't know much about sealants. Hopefully there'll be a recommendation from someone. I think sealing up is not critical because airflow is not huge at non-bass frequencies. Maybe the paint and whatever PL is in the joint may be sufficient?

[Oxonjohn]

You would definitely have to fit at least the top baffle support after the baffle to do it that way. Unfortunately I had already fitted the baffle supports (as per the plans!). It seems to have worked OK - the residual adhesive which didn't get wiped off appears to have expanded enough to seal it. I'll probably still add a fillet on the front though. You mentioned you had used something for this - can you remind me what it was?

John

[Charles Jenkinson]

Cheap acrylic (water based) caulking. Adheres and is paintable.

[Oxonjohn]

It's been slow going for the last couple of weeks due to other commitments, only managing to cut the back door and fix the flanges on the cab and door. I managed to get back onto things this weekend, rounding over the edges, filling holes, sanding down and adding acrylic sealer fillets to the visible joints (thanks Charles). Rounding over was reasonably straightforward and a very satisfying job with the router (how did I get through 48 years without realising what a great tool a router is!). The angled edges were a bit tricky though and needed finishing off with a sander.

I decided to use bolts and tee nuts to fix the back door - I suspect I will leave it in one configuration (open backed or sealed) once it's fully broken in so I don't think I'll miss the quick release catches.

[Oxonjohn]

Just finished my first coat of Tuff Cab (UK product, similar to Duratex I believe). Brushed the inside, rolled the outside with a textured foam roller. Really easy to apply, and appears to cover up all my remaining minor flaws. Hope it looks (and feels) good once it dries.

[Oxonjohn]

Just about finished. The Tuff Cab looks fine, though in hindsight I would brush on the first external coat and only roll the second coat with a textured roller. Metal corners finish it off nicely and are easy to bend to the shape of the angled sides. I was going to fit the handle using tee nuts for strength but the balance point means the handle needs to be fixed just in front of the baffles. As I'm using individual grills per driver rather than one grill over the whole front, the tee nuts and bolts would have been visible. I just used 5/8" screws in the end - the cab is so light that I think they should survive OK.

I've stapled wadding to all the inside faces, though I haven't finished the back door yet so I guess it's a bit superfluous for open backed use. I glued a piece of thin ally on for the jack plate with a printed label over the top. Two jack plugs were fitted so I can run the drivers wired in parallel from one socket or individually from both sockets if necessary. I didn't seal a box behind the jack plate as suggested earlier - I'll use the method of putting a foam ear plug in the unused socket (mentioned on another thread) if I use the cab sealed.

Had a quick low volume functional check and everything seems OK. We've had to move everything out of our rehearsal room this week so I'll not get chance to try it at war volume for a week or two. It will give me a chance to finish off the back door and check for leaks first.

Sound pending, I'm really pleased with how this has turned out. Size and weight are great, it looks far less DIY than I thought it would (even my wife commented how professional it looked) and it's good to have something a bit different. I'll take my time to break the drivers in properly before drawing any final conclusions on the sound, but I look forward to finding out how different it is with regard to dispersion, beaming and on stage coverage.

I'm glad I built this before building a more complex PA cab - I learnt a lot from the process (I haven't done much woodworking since school and this was my first time using a circular saw and router). Although it's over a month since I started I reckon I could now build one of these in a weekend if I set my mind to it.

I'll post a lessons learned list soon. Once the drivers are broken in (maybe a couple of months) I'll post a video review of it running with my Ampmaker PP-18 head (also homemade) back to back with my old Vox AC10.

Thanks to everyone who has offered advice - there were a few times when I definitely needed the help.

John

[Tom Smit]

Looks good, John!
As far as how much time has gone by for the build, you did well.
What is this --|
................... \/

thin ally

Adn yes, this is a great forum.

[Oxonjohn]

Thanks Tom.

Ally = aluminium (or aluminum for you guys on the other side of the pond!)