RichardH Posted June 12, 2017 Share Posted June 12, 2017 Cheers Stevie - maybe it was in the mk1 thread I read comments about a lower tuning.... or maybe I dreamt the whole thing Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted June 12, 2017 Share Posted June 12, 2017 You're right, we did try the 40Hz tuning for the MK1, the 50Hz sounded better and had better power handling over the important frequencies. Quote Link to comment Share on other sites More sharing options...
RichardH Posted June 13, 2017 Share Posted June 13, 2017 (edited) Just priced up the components via [url="https://www.hificollective.co.uk/"]HiFiCollective[/url] They don't keep the inductors in stock, but their prices are reasonable. They even do the [url="https://www.hificollective.co.uk/catalog/tag-board-p-695.html"]tag board[/url]. So including shipping, the parts come to £21.15. Then all you will need is some 6mm ply or similar to mount the circuit on. Am wondering about just getting some bare paxolin board and mounting the crossover on that, then just adding terminals for the connectors. I was thinking of doing it all with turret connectors, but you usually have to buy them in bulk, so not good for people to follow suit. What does the panel think? I would like to do it in the easiest way for others to follow, so best to keep the tool count down as much as we can. Edited June 13, 2017 by RichardH Quote Link to comment Share on other sites More sharing options...
stevie Posted June 14, 2017 Author Share Posted June 14, 2017 (edited) I'm used to designing and using proper fibreglass PCB boards, but they do need to be produced in quantity. I've experimented with a variety of materials for one-off builds, and 6mm ply and tag board is the best solution I've found so far. 6mm ply is also very cheap, but the problem is getting hold of small pieces. Wickes and Homebass sell a 1200 x 600mm sheet for about a tenner, and I'm sure there must be wood merchants and joiners prepared to sell smaller sheets of offcuts (my local DIY shop does). Anyone building their own cab from 15mm poplar ply could use offcuts of that. Homebase also sell a 1200 x 600 sheet of 6mm MDF for £6. Edited June 14, 2017 by stevie Quote Link to comment Share on other sites More sharing options...
RichardH Posted June 14, 2017 Share Posted June 14, 2017 Yes, I think that's the way to go. You can buy blank PCB board fibreglass - or phenolic board - on eBay, but equally you can also buy small bits of ply as well. Actually, I've just remembered, I have a huge chunk of thin ply left over from dome house DIY. Geoff is up for having a crossover built, so I will buy the bits and document the process for anyone else feeling nervous about doing it. Quote Link to comment Share on other sites More sharing options...
stevie Posted June 14, 2017 Author Share Posted June 14, 2017 Excellent! That would be very helpful. Quote Link to comment Share on other sites More sharing options...
stevie Posted June 14, 2017 Author Share Posted June 14, 2017 Incidentally, Richard, I have sheets of blank PCB board fibreglass in my workshop, but I still find it easier to use 6mm ply. It doesn't look quite as "pro", but that doesn't really matter. Quote Link to comment Share on other sites More sharing options...
Beer of the Bass Posted June 14, 2017 Share Posted June 14, 2017 There are lots of ways to skin a cat, but the method I've been using to make eyelet boards for valve amps might be applicable to crossovers. I use 2mm phenolic sheet bought cheaply from eBay suppliers (easier to cut and drill than fibreglass, more resistant to soldering heat than ply) with brass haberdashery eyelets set into holes (easy to solder to, cheaper than turret terminals). Larger components are held in place with hot glue or cable ties. Quote Link to comment Share on other sites More sharing options...
RichardH Posted June 14, 2017 Share Posted June 14, 2017 That sounds a good way to do - I had been thinking of using the phenolic sheet. The eyelets idea is genius - that way you can pass leads though the board rather than keep it all on the surface. I guess a punch tool might be needed too, though I wouldn't be suprised if that can be got around without too much trouble. If I go that way then I wouldn't mind knocking up a few blank boards for anyone else who wants to build a crossover. Quote Link to comment Share on other sites More sharing options...
Beer of the Bass Posted June 14, 2017 Share Posted June 14, 2017 [quote name='RichardH' timestamp='1497441141' post='3318144'] That sounds a good way to do - I had been thinking of using the phenolic sheet. The eyelets idea is genius - that way you can pass leads though the board rather than keep it all on the surface. I guess a punch tool might be needed too, though I wouldn't be suprised if that can be got around without too much trouble. If I go that way then I wouldn't mind knocking up a few blank boards for anyone else who wants to build a crossover. [/quote] I don't have the proper eyelet setting tool, but I've found it works OK to place them in drilled holes, turn the board over and splay the other side by tapping them with an old centre punch. Quote Link to comment Share on other sites More sharing options...
stevie Posted June 14, 2017 Author Share Posted June 14, 2017 [quote name='RichardH' timestamp='1497441141' post='3318144'] That sounds a good way to do - I had been thinking of using the phenolic sheet. The eyelets idea is genius - that way you can pass leads though the board rather than keep it all on the surface. [/quote] There is no wiring on the surface. The layout is as it would be for a regular printed circuit board, with all the component wires passing through holes in the board and then being hardwired underneath the board (instead of being connected by PCB track). The holes at the right hand side of the tag board are where the wires come back up through the board to connect to the tags. I think a photo would have saved a lot of confusion here. Quote Link to comment Share on other sites More sharing options...
RichardH Posted June 14, 2017 Share Posted June 14, 2017 No, that is what I had assumed - all the wiring would run under the board, but I was a little hesitant to run wired through ply and have the resistors hard up against the ply surface - though I guess they aren't going to get that hot, so it's not really a problem. Quote Link to comment Share on other sites More sharing options...
stevie Posted June 14, 2017 Author Share Posted June 14, 2017 (edited) OK, good. The resistors won't get hot enough to damage the ply. A couple of tips for crossover assembly. Use non-ferrous screws, brass or stainless steel, close to the coils; anything ferrous will alter their value. Use silicon sealant to glue the components down. Unibond Power Extreme also works well but is a bit pricey unless you can get the Aldi version. Don't use heat glue; its shear strength is poor and the heavier components will become detached if the cabinet is dropped. Use cable ties generously. Edited June 14, 2017 by stevie Quote Link to comment Share on other sites More sharing options...
Pea Turgh Posted June 15, 2017 Share Posted June 15, 2017 Hello chaps. Just read this thread start to finish and I'm kinda interested in having a pop at it. One thing first though, I currently use a Peterson P120 (and love it). Just need a little bit more oomph. Would swapping out the stock driver in my Peterson in favour of the 12" Beyma be sufficient? Currently the output volume dial doesn't go past 12 o'clock. If I had a higher rated speaker, I could put more wattage in. I know a low power amp can still total a high power speaker with square waving, and maybe the speaker in there already is more sensitive (doubt it as it's about 35yrs old). I also had a crazy idea of making a separate enclosure for just the crossover and had driver to sit on top of the combo (The cabinet is mahogany and looks the business). Thanks in advance, Pete. Quote Link to comment Share on other sites More sharing options...
Pea Turgh Posted June 15, 2017 Share Posted June 15, 2017 (edited) Hmm... just measured my cab internal dimensions- about 36 litres. Pulled the driver out to see what it is - it's an Electrovoice EVM12L. From what I googled, it's a guitar speaker. Weird. Would the Beyma be a worthwhile upgrade? Edited June 16, 2017 by Pea Turgh Quote Link to comment Share on other sites More sharing options...
RichardH Posted June 17, 2017 Share Posted June 17, 2017 I'm no expert, but at 36l, that cab sounds like it might be a touch small for the Beyma - it will depend a lot on the porting arrangement on the Peterson. If you can measure the port (width, height and depth) then that will give more info. Quote Link to comment Share on other sites More sharing options...
Pea Turgh Posted June 17, 2017 Share Posted June 17, 2017 (edited) Hello. The ports are either side of the amp, slot style. So 2x 3cm wide, 41cm high, 25cm deep, with a very small 1cm gap at the back (top to bottom). I've thought about removing the internal box bit so I could have the full 46cm internal width - that gives me another 10 litres! Will modifying this cabinet and switching to the Beyma be a worthwhile exercise? Or should I just build the BC cab, buy another amp and be done with it?! Thanks for taking the time to respond! Edited June 17, 2017 by Pea Turgh Quote Link to comment Share on other sites More sharing options...
RichardH Posted June 18, 2017 Share Posted June 18, 2017 So do you mean the full depth of the cab is 25cm, but the panel that forms the side slot is 24cm (leaving a 1cm gap for the air to pass through from the main body of the cab out through the slot)? If that is the case then I don't think the Beyma will work very well - from a rough and ready plot in WinISD the bass will roll off a lot sooner than the BC112, and there will be quite a big "hump" at 100Hz. Quote Link to comment Share on other sites More sharing options...
Pea Turgh Posted June 18, 2017 Share Posted June 18, 2017 Cool - thank you for checking that out! I think I'll just go ahead and make the cab that has been tried and tested! I can keep the mahogany beast in the house to run my Pianet through. I can't believe how small amps are these days. It'll be nice to pick up a rig and not sh*t myself with strain. Gotta start looking after myself these days, innit! Thanks again, Pete. Quote Link to comment Share on other sites More sharing options...
Beer of the Bass Posted June 18, 2017 Share Posted June 18, 2017 [quote name='Pea Turgh' timestamp='1497792596' post='3320569'] I think I'll just go ahead and make the cab that has been tried and tested! I can keep the mahogany beast in the house to run my Pianet through. [/quote] Ooh, N, T or one of the other Pianets? I love those things, and have an N myself. I think I like it best through a guitar amp rather than bass or full-range amplification though. (Apologies for dragging the thread way off topic!) Quote Link to comment Share on other sites More sharing options...
RichardH Posted June 18, 2017 Share Posted June 18, 2017 [quote name='Pea Turgh' timestamp='1497792596' post='3320569'] I think I'll just go ahead and make the cab that has been tried and tested! I can keep the mahogany beast in the house to run my Pianet through. [/quote] Much the better idea. Quote Link to comment Share on other sites More sharing options...
Thunderpaws Posted June 20, 2017 Share Posted June 20, 2017 I remember the group was putting together plans/drawings/instruction guide for Mk1...did that ever happen? Quote Link to comment Share on other sites More sharing options...
Thunderpaws Posted June 20, 2017 Share Posted June 20, 2017 I remember the group was putting together plans/drawings/instruction guide for Mk1...did that ever happen? Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted June 21, 2017 Share Posted June 21, 2017 The plans are all there in the original thread. Unlike Stevie I didn't get round to putting up all the relevant bits at the beginning of the thread. Bass playing keeps getting in the way. Quote Link to comment Share on other sites More sharing options...
Pea Turgh Posted July 16, 2017 Share Posted July 16, 2017 Ooh, time. It's in short supply! Still interested in doing one of these, but won't get around to it til 2025. Anybody building one fancy doing a second? Throw me a price for the wood assembled!?! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.