jam1n

Nice! How tall are they. I can't seem to find the height online.

Thanks Adams. Makes sense. I'll give this a go.

Thanks everyone. Thanks genek. Mine are now in alcoves, either side of a fireplace, which comes close to this, on one side at least. The Roy Allison articles help to explain why this seems to help. Thanks Aaadams! Giorgio, I found the full Roy Allison paper online here and (of course!) in the CSP library here. Interesting reading but a bit too technical for me at points. I also found this article, which is a bit more accessible. It gives a simplified overview of the conclusions from his research and describes a computer program he made to model the effects of room placement on output. I also found the program itself in the CSP library to download here.😄 If I understood it correctly, the conclusion of these papers was that the best placement (if not recessed) is where the distance from the rear wall, nearest side wall and the floor are as different as possible, which also chimes with what samberger said: Mine are now backed up against one wall, recessed in an alcove, about a foot off the floor and two feet from the side walls. Seems to work but it’s nice to understand a bit more about why. The one thing I’d like to understand better is why I seem to prefer them tilted backwards. I think I read something PeteB said on the forum about this at some point but I’ve not been able find it again. I did. Sounds like fun! Any advice for how best to accomplish it?

I've just finished restoring a pair of AR-3a's and I'm interested to know how people find they get the best sound from them. I've read a few comments here and there on the forum but couldn't find a specific thread on the subject. So, how do you find the AR-3a to sound its best? Against the wall or out in the room? Toed in or parallel? Tipped back slightly or level? I know some people say they should really be on their sides but that's not an option for me at the moment due to the space. I have mine on home made stands, tipped back about five degrees. I had been enjoying them toed in, a couple of feet out from the wall but since rebuilding the crossovers, I'm finding that I like them better parallel, back against the wall. It seems to open up the sound stage in every direction for a much more immersive listening experience. What works best for you? Ben

Here are a few pictures of the original AR-3a Improved crossover I removed from the cabinets and the AR-3a Limited crossover I built. Not bad for a complete novice. I couldn't have done it without all your kind help! 😃

Thanks for all the help everyone - especially RoyC and JKent! I managed to finish the crossovers, with a bit more help along the way from Roy. The speakers are now fully re-built and sounding fantastic. I'll post some pics of the crossovers below. I have one more question. What position should the l-pad knobs be in for a flat response? Thanks again! Ben

I’m nearly ready to build the crossovers. I took Roy’s advice and matched the original spec as closely as possible. I have all the capacitors/inductors and some18ga tinned copper wire. I‘m just waiting for the L-Pads and a decent soldering iron. Does anyone have any recommendations on what to use for the crossover board? I have various bits of scrap wood lying around, including wood fibre board, chipboard, ply and MDF. Both the pictures Kent posted look like pine boards. Is solid wood better?

Thanks Kent Does this look like the kind of thing you had in mind? https://www.ebay.co.uk/itm/154026431801 Ben

Thanks for your help everyone! My crossover upgrade project has been on the back burner for the last few weeks while I finished up restoring the cabinets and gave my wife a well-earned rest from discussions (i.e. monologues) about capacitors. I had some trouble with one of the joints where the water damage was quite bad but I got there in the end. I still have to finish the grills but the speakers are looking much more presentable and I'm confident they are now structurally sound. I received the new Midwest tweeters a few weeks ago. It took a bit of getting used to the change as the original tweeters' output was very low and I'd been quite enjoying that rolled off sound. I thought there was a problem with them at first as I got hung up on the sibilance in Diana Krall's 'Stop this world' – until I listened to it on my headphones and realised it was on the recording. I also thought I was losing my hearing in one ear for a while until I realised that a bad contact meant there was no output from one of the new tweeters after I installed its foam gasket. I thought I was going mad for a while but, now everything's working properly, the speakers are sounding amazing and I'm falling in love with my music collection all over again. I'd still like to rebuild the crossovers, but I'll probably wait until September, when the kids are (hopefully) back at school and I should have a bit more time. I might order a basic capacitance meter in the meantime, so I can see how close to spec the capacitors are actually performing. For now, I'm just enjoying the music!

Hi IARybody. Thanks for the recommendation. Is there any benefit to using the ‘plain’ ECaps in the woofer bypass as well or would the ‘raw’ etched version suffice here since it’s not in the signal path? Also, what are your thoughts on the 4uf (with the Midwest AR-11 type tweeter)? I noted on this thread that you’ve used the Jantzen Superior/ClarityCap CSA/Mundorf Supreme. I’d love to know how you’ve found these compared to the Daytons, whose virtues I saw you extolling on AK in an older thread. Which do you think would play best with the ECaps? I’m leaning towards the CSA, on the basis that they might help to tame the slightly forward character of my amp in the top end. But I’m also very curious about the Jantzens. Any thoughts? Ben

Thanks Kent. Very helpful indeed. Your comment about ESR sent me down another very interesting rabbit hole. I think I understand better where Roy is coming from now. Keeping to the spec they were designed to makes a lot of sense. It's probably the sensible place to start. From what I read about ESR, it seems that using three 50uf caps in parallel would significantly reduce the ESR. I can get 50uf/100V ALCAPs selected with a 2% tolerance from Falcon Acoustics here in the UK, so I'll probably do that for the woofer circuit to match the original. I'm still on the fence about the mid. It seems there are some advantages to film caps but also some potential drawbacks in deviating from the original crossover design. I'm going to have to give this one a bit more thought. Ben

Thanks Roy My priority is to get the speakers sounding the best they can. I've been enjoying them a great deal already, but I sense they're capable of more. I had the impression the consensus was that film caps sound better than electrolytics when used in the signal path? I'd planned to use NPEs for the 150uf and film caps for the rest, as per Kent's advice above. I was looking at the Mundford ECap for the woofer circuit. The 150uf is only 63V and they don't have a 50uf but I can combine 68uf + 82uf to get to 150 and the 100V version is very reasonably priced. Would that do? The 40uf film cap I'm looking at for the mid is not too expensive either. The speakers were given to my father by an old neighbour whose wife considered them an eyesore, so I don't mind spending a bit to breathe some new life into them! Unless you think they'd sound better with an electrolytic capacitor in there as well? Ben

Thanks Roy 18 it is. I'm glad I asked! Just to double check the inductor values before I order: L1 - 2.60 mH L2 - 0.7 mH L3 - 44 uH = 0.044 mH L4 - 160 uH = 0.16 mH Also, what width of gasket tape do I need for the drivers? The woofer foam needs replacing and one of the tweeters didn't have any at all! I'm in the UK. I've never been a particularly patriotic person but, in these bizarre times we live in, I'd like to support the HiFi industry here if possible and I've heard good things about ClarityCap from people whose judgement I trust. I realise that 'high end' capacitors are a divisive issue and I'm not looking to dive too far down that rabbit hole, but I was tempted to go slightly higher up their range. Doubling up to make exact values gets expensive pretty quickly though, so I think I'd better rein myself in! Ben

Thanks for the pictures, Kent. That really helps to visualise what's involved. 😃 I'm putting together a parts list and I have a couple of questions about how accurately I need to match the coils/caps in the limited crossover. Jantzen seem well regarded and do custom value inductors. There's a longer lead time but I'm in no rush. They have 17AWG/1.2mm & 18AWG/1mm coils. I'm assuming that 17 would be better than 18 if that what was used in the originals but, in some of the coil values, they have two 17AWG options with different stated DCR. After reading RoyC talking on another thread about how important it is to match the DCR of the originals as closely as possible, I'm wondering if anyone knows the values for the coils in the limited crossover? Or am I over complicating this? Obsession with detail can be a blessing and a curse - sometimes it's hard to tell which! 😜 In a similar vein, the closest values I can find to 4uf/40uf in most ranges of capacitors are 3.9 & 39. That's off by 2.5%, which is within the tolerance range of most of the capacitors I'm looking at. Is this close enough, or is it worth spending the extra to make up the exact values by combining caps? Thanks again Ben

Thanks Kent! No offence taken. I'm not sure yet, which is why I want to understand as much as possible about what's involved. But I do enjoy a challenge and I like learning new skills. I've spent a lot of time reading on the forum and I get the impression this would be the best way to give these speakers a new lease of life. Also, I'd like to replace the binding posts and the capacitors at some point and, please correct me if I'm wrong, but I got the impression it might actually be easier to build a new crossover than doing that with the existing one in place. BTW, thanks for all your advice on the forum about cabinet repair (and Glen's), which has given me the confidence to tackle some nasty water damage where a few of the panels have separated at the joints. I've restored a few pieces of furniture before but this was by far the most ambitious repair I've taken on. I finished the first cabinet this afternoon and it has come out very nicely! One more question. There is a 0.51 Ohm/22W resistor in the limited crossover. So far, I've only found a 10W one. Would that be an acceptable substitute or do I need to find another option with a higher power rating? Ben