Obrienp

Just to tie off my previous off-topic post but I think I have fixed the vibrations in my BF Two10 cab. Judicious use of silicone sealant, epoxy glue and some rubber tape off fleaBay seems to have cured it.

Sounds like a good option for somebody. 👍 I’ll keep you posted. Probably in panicked calls for help when I mess up😏. Just collecting the parts at the moment.

Thanks for the offer but I already have the GPA -100 power amp, plus I currently have 4 amp heads. I really need to cull the herd a bit rather than enlarge it.

I have a Gnome iPro and I really don’t like it with the Monza. It is possible to get a sound I like with that combination but the EQ settings have to be really radical and there is nowhere to go for variation once it is dialled in. I already have the HB GPA-100 power amp, which I use occasionally for guitar with a multi effects pedal as preamp. I have also used it with a Monza and Bass Flyrig V2 for rehearsals and small gigs. The advantage of the Flyrig is that it has two preamp channels and all the effects I use built in, a tuner, plus a good DI (it’s raison d’etre). It just reduces the kit required in cramped conditions. An active cab would reduce it further but I really don’t like the affordable options available at the moment. I could use a 12” active PA cabinet but it doesn’t look right. Also I want the challenge of building a cab and the sense of achievement when it’s built.

Thank you for the advice @Phil Starr. I hadn’t thought about thicker ply changing the internal dimensions. I will have to do some calculations to make sure I am getting at least 30 litres internally. I have decided to go for @Chienmortbb’s 12PR320. It will save me quite a few quid over buying a new one and keep the overall cost down. I wanted to do a 12” simply because I have 10” well covered by my Monzas and BF Two10. I had a little Mark Bass 8” combo and that has somewhat put my off 8” drivers, even though the real limitations were in the EQ department. Illogical I know.

Sounds brilliant! Unfortunately, I think it is going to cost quite a bit more now but still worth it IMO.

I hope this thread isn’t dead, as I am hoping some kind soul will be prepared to answer a few questions. I fancy taking on a simple and relatively cheap 12” cabinet build. I say relatively cheap but everything seems to have got a lot more expensive since the last post above and some of the drivers mentioned don’t seem to be available anymore. However, if I can come in around £250, I will feel it was worth it and hopefully will enjoy the process. I actually want to build a powered cab using the Harley Benton GPA-100 power amp. I’m thinking of extending the height of the compact cab in this thread (30L) and putting the GPA in a full width box on the top. This would provide a simple, relatively light (I hope) cab for rehearsals and small tricky acoustics gigs, when I don’t want to use a big amp and my LFSys Monza(s). I would use my Flyrig 2 for the preamp. Anyway, the GPA can churn out 200 watts at 4 ohms, so I was thinking of getting a 4 ohm speaker rated at 300 watts RMS/AES to get some headroom. Although not cheap, I was thinking of something like the Faital Pro 12 PR 310. Would this 30L design be OK for something like that, or would it require more cab volume? Having recently been unimpressed by the 10mm ply in my BF Two10, I was thinking of using 15mm. Will that have a huge impact on the weight? Apologies in advance for directing more idiot boy questions in the direction of @Phil Starr, among others.

Interesting! I guess that, plus the positioning further from the neck, is what makes the sound less like a Gibson mudbucker. The name “Bi-Sonic” is misleading then. I may have gone too far towards the mudbucker tone with the humbucking P-127 then. However, I have the ‘60s British Invasion bass tone in my head and a lot of that was achieved with Gibson humbuckers.

Well I’ve got through stage one of fitting the DiMarzio P-127 set. This was not without a few tech issues. I was delighted to score 3 CTS 250K audio taper pots with long shafts on FleaBay for just under £10! I have not seen these on sale in the U.K. before (250K with long shaft). Unfortunately, I just couldn’t get them to go through the f-hole, however I tried. Ditto full sized Alphas. The only mini pot I had in my parts box was an Alpha 100K B but having got everything else into the bass, I was keen to have something to play, so I put it in but using screw terminal blocks to connect it up. I am now waiting for a CTS 250K A mini-pot. The P-127 is meant to be pretty hot, so I was kind of expecting the 100K pot to tame it. It still has a lot of grunt but does sound a bit blunted. I am reserving judgement on whether the P-127 is going to give me a tone close to a big humbucker. It certainly has some of the qualities of the D-145 mudbucker I have in another bass. It’s definitely punchy and has more bottom than your average P. I am reserving judgement until I have tried it with a 250K pot. One thing that seems to be a bit worse, is the amount of hum coming from the bass. I added some copper tape to improve the shielding in the pickup cavity and I may have made the hum worse. I am not sure if the earth wire in the cavity is connected to the ground properly. I can remedy that when I change the pot. It seems that the chrome pickup covers act as an antennae for interference when I touch them. I need to make sure they get grounded properly. Here is a pic of the P-127 set in situ. I need to realign the treble side to eliminate the slight gap. Fortunately the rails are not touching the chrome covers. More to follow after fitting the 250K pot.

Bardzo dobrze!

Thank you again for the advice. I’m pretty sure the switch is Barefaced OEM. I found a video of Alex demonstrating the procedure for opening up a Two10S and the switch assembly looked the same. It was meant to be a demo of installing a switch kit but he used a Two10S and just discussed how to install the kit, rather than actually doing it. I don’t think I would have found that too helpful, if I was about to try to do it. However, he did mention that the coil and magnet assembly tie-wrapped to one of the speaker frames should be removed. It’s still there in my cab, so it’s obviously a conversion that wasn’t executed perfectly. I’ve been searching for written instructions on their website but very few of the technical links seem to work anymore. An email to Alex is in order.

I bought an Ashdown RM 800 from Paul. It was a very smooth and easy transaction: great comms, well packed and promptly dispatched. The amp was as described and I am very happy with the whole transaction. Buy with confidence.

Thank you for the suggestion. Fortunately, it was just a little damage to the ply where the feet were located: the two on the front side of the cab, so I was able to inspect it thoroughly when I removed the drivers. The only internal bracing is the internal baffle board assembly, as far as I could see. There is certainly nothing loose inside. I reinforced the area where the ply was damaged with some rectangles of 8mm ply, glued and stapled. I am pretty sure that is not moving and the buzzing is not coming from that area. TBH this cab always vibrated a lot at volume. I guess that is what comes from the lightweight construction: 10mm ply throughout. I always put a non-slip mat on top when gigging it. The buzz is something I hadn’t noticed before but I haven’t used it for a while. I have been using my LFSys Monzas, which are made of thicker ply and don’t vibrate as much. Now I have heard the buzz, I can’t un-hear it. I probably do need to consult Alex but I wanted to get an impartial view first. Unfortunately, the cab isn’t insured and the incident with the feet happened a couple of years ago.

Thank you @Phil Starr for the advice. Unfortunately, it looks like that DPDT switch (which, as you say is very standard) is attached to the PCB stuck on the back of the unit. I am not sure whether it will be within my capabilities to replace it. That PCB is mounted on a 50mm chunk of ply attached to the metal plate. Not sure why they did that. I assume it was to give it sufficient mass to resist vibration but it also protrudes a long way into the cabinet. I would have thought creating a long lever would make it amplify any movement in the plate. One supplementary question: should there be any wadding in the back compartment of the cabinet; ie the space behind the internal baffle? Would it help reduce the resonance if I put some in? I would be careful not to block the port that is at the bottom of that compartment. At the moment the cabinet vibrates so much (when I hit Eb, E, F) that the amp starts to dance about on top. Thank you for your forbearance. As must be obvious, this is far from my area of expertise.

I hope this isn’t hijacking this thread but the conversation by @Phil Starr and others about internal acoustic damping is very timely for me as I am trying to sort out a few little issues with my Barefaced Two10S, which has caused me to remove the drivers at one point and notice the internal damping material. I took the drivers out as I was implementing a long term fix to the anchoring of the feet on the long side of the cab (horizontal position). One had been torn out and another bent at an angle (over enthusiastic helper at a gig). I did a temporary fix with filler but the screws had started to work themselves free recently. On inspection the thin ply had been weakened around the screw holes, so I decided to use threaded captive nuts and reinforce the two damaged areas internally with rectangles of 8mm ply (glued and stapled). In the process I noticed that the white damping material appeared to have come away from where it had been stapled (staples still there but material scrunched up). I put it back where it had obviously been and re-stapled it. This formed a lining on four sides against the internal baffle board but not on the speaker baffle. It covered the slots in the internal baffle board. Is this correct? Strikes me it must be restricting the flow of air into the reflex chamber in the back of the cab. Should it be like that? On reassembly (with new speaker mounting bolts), I tested it with a Mark Bass LM111 500 with gain at 12 o’clock and EQ the same, filters off and master at about 11. I immediately noticed there appeared to be a distinct resonance around Eb, E, F accompanied by a sympathetic buzzing from somewhere on the cab. I eventually tracked this down to the switch plate on the back. The retaining screws weren’t that tight and couldn’t get proper purchase in the 10mm ply, so I eventually resorted to T-nuts and hex bolts, plus rubber draft excluder to make a gasket. This improved things a bit but did not eliminate the buzz. It really is in sympathy with the cab’s resonance around E: high pitched on a high E and low when I play open E. I think it is actually coming from the DPDT switch itself and that is probably something I need to seek advice from Alex about (new unit is around £120 😱, well that is what the switch conversion kit costs). All the above said, I noticed that there is no damping material in the back compartment of the cab. I am just wondering if putting some in might damp down the resonance around E, or will it just mess up the function of the reflex and port? Apologies, if I should be posting this in a different thread. incidentally, I am interested in making my own little low wattage cab like the BC 8” cab but I want to embed my HB GPA-100 power amp in it somehow, without it overheating (convection cooling). More of that later, when I have sorted out the Two10.