Possessing no talents myself, all I can say is damn, well done 
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Great read and once again 
on the job you have done with those crossovers, brilliant.
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I have gone gloss black on the cases for the cross over, there is a bit too much wood going on 
I feel like I am getting half way good at piano black.
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I honestly thought about it for a long while but in my space probably a bit much!
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What a finish
You are king. Unbelievable - as ever.
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I have deep respect for people that can do things like this. I canât even drill a hole properlyâŚ
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Its all self taught or looking at youtube. To be honest I am slightly bewildered I did it lol.
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There were a few good reasons my original custom PAXO were designed for the speakers to be somewhat away from the rear wallâŚ
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The 15â driver is capable of prodigious amounts of bass and should not need boundary reinforcement.
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Here in the USA, unless you have the speakers on an outside wall, the rear wall will be flimsy sheetrock with hollow cavities, and will not provide the bass reinforcement that they ideally should.
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The XO was also optimised for toe-in to enhance imaging, and if you toe speakers in, they cannot be fully wall-braced.
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I had plenty of space in what I thought would be my âforeverâ room, so pulling them a bit out was no problem.
Over 200 different x/o designs were modelled using at the time the best available software (the LEAP). And the guy who designed my XO also wrote the XO design software for LEAP.
Anyway, the final chosen XO version seemed to offer the best balance between compensating for the intrinsic in-cabinet non-linearities of the drivers, extended LF response, increasing the bandpass HF point for the tweeter-which essentially cures its proclivity to self destruct at âmodestâ listening levels, and a very smooth phase response.
For the first year I had the new XO, I kept the original PAXOs bolted on the rear of the speakers, and every so often I would swap back to them just for reference. I donât think they stayed in place for more than an hour thoughâŚ
Over the years the design maturedâŚnot in topology, but in parts quality. The original tape foil inductors in the LF were replaced with toroids that had much lower DCR, Solen caps replaced with Cardas, Mills resistors replaced with Duelund or Path. I think if I was having a set put together today, I would look at Duelund, VCaps or Jupiter to replace the long-since discontinued Cardas caps.
As adventurous as I thought my x/o were at the time (?2003) what garyi is doing is on an entirely different level.
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I would put DBLs with a well-sorted XO against pretty much most active versions. The SNAXO was no better in sound quality than a 72, even with a formidable Supercap strapped to it-and could be the bottle-neck.Indeed a friend of mine who was running his DBLs with 3x500, SNAXO/SC greatly preferred the custom passive XO and a single 500.
The DBL really needs a 500 series SNAXO, which never was made.
The X/O that garyi has made would probably retail for $20k if they were made commercially, which is almost double of what I paid for my DBLs in the 1990s.
I would have guessed 12k. Component cost with the boxes and the silver solder and what have you has topped 2.2k. in terms of where I could have gone the sky is the limit. The mundorf are considered mid range.
But itâs the knowledge and the skill that I donât possess. Itâs been a wonderful learning experience and I hope I have made a friend along the way as well.
Listened last night five hours of pure joy just hitting the library for all the songs lol.
I am not in a position to say component quality makes a difference. I was not replicating a cross over after all so have no reference. I can categorically state that a cross over designed from your own room measurements is next level
Is this a service any company anywhere offers?
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I bought the Sean Jacobs PAXOs for my SBLs, I think @RonToolsie had some input on the design?
From what I know, Sean Jacobs offers PAXOs for the DBLs, but doesnât advertise.
SJ built a set of DBL x/o for a forum member who lives in London (SB) that was the exact schematic that I provided. This was supposed to be a one-off.
If he still offers DBL PAXOs, it probably still is this design.
Iâm not sure if the SJ SBL PAXOs are the original Naim schematic or a complete redesign.
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On your PAXOâŚdo you know what the bandpass frequencies are centerd around?
I got tired of getting a new matched pair of tweeters every year, because they were cutting in at the low end at a frequency that could easily have been handled by the MR drivers, with made them blow at annoyingly frequent intervals.
I see,you wanted a very different speaker design
Was this based on the original PAXO network specifications but with better components, designed for use spiked on a concrete floor with the speaker backed as close as possible to the brick wall behind it?
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So anyway part of the reason for reopening this thread was to to conclude it. As I stated right at the beginning, I got these on the understanding that the bass drivers were not original.
Now I have no idea how these landed up in the boxes. But it turns out that thanks to a fluke facebook marketplace listing (or are they spying!) the bass drivers in my speakers are celestion. Specifically BL15-300X. The parameters of these are quite different to what shipped so I have no idea what the deal was here, whether someone swapped them out for these or what.
But for me, it became a bit of an obsession to get these speakers as stock as possible. I tried all avenues, including ATC themselves. Sadly the baskets are no longer available and have not been for some while. They can repair, they cannot supply.
So for months I have had searches out on ebay etc but nothing came up. I also dropped James at tomtom an email I have been keeping him appraised of developments. After a while some hopeful news popped back. âI may have some, âIâll let you knowâ.
After another month of a search to find them, I am happy to say I can close out this story to some extent. James dug out a NOS pair of drivers for DBLs.
Without doubt, James has wanted to see these speakers enjoyed. I honestly think he is pleased to see where these landed up. Without doubt he took a wash on the drivers, he sold them to me at a great price. Honestly I am so delighted to round out these speakers. Turns out to be one of the later pairs to be made by a guy call Toby at ATC who retired a few years ago. Excellent!
So here I am with a broadly speaking, âproperâ pair of DBLs. With what I think is an excellent history.
The only thing missing was the bespoke filter on the back, which some 3D printing sorted
Now obviously this has implications for the Crossover. This is the beauty of the three board approach. It should hopefully be minimal or at least contained challenge to sort out any changes. Though I wonât lie, they sound phenomenal. I have been listening for a fair few hours now.
Another thanks goes out to James at Tomtom. This is honestly I guy I would like to call friend one day. So knowledgable and approachable. I know like myself, he wanted to see this worthwhile project out. What a fantastic journey!
Also to my new found friend helping me with these crossovers, such an interesting project, boarding on obsession, but the best kind!
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It was the completely new redesign, and not anywhere close to the original PAXO. So it would perform better away from the rear wall.
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This was Ronâs design, (as specified to SJ) with âhigh qualityâ components.
I keep mine pretty close to the wall, but will now experiment a bit more given Ronâs âaway from the rear wallâ statement.
They transformed the DBLsâŚ
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