Hi fellow hifi tinkerers
I have recently been given 5 pairs of Goodmans Magnum speakers (yeah, you did read that correctly!) in what I believe was a house clearance from someone who clearly liked Goodmans and horded them (or worked for them and ended up with stock sitting at home, can't decide which!)
I don't really want to necro old threads despite there being a few of them so here goes...
I've got: 2 pairs of K's and 3 pairs of K2s. Some googling and linking from other forums seems to suggest that this is the place to be if one wants to alter these models. One of the Ks is the original birch ply construction and is in pretty good condition bar a couple of dents, even the Lpads seem to work well, not that I care too much for them. The other is chipboard and smells like an old fish tank inside - but the drivers appear pristine, thankfully!
One pair of K2s have been extremely well looked after and are almost pristine, one pair are in 'ok' condition, and the last ones are working but are very poor cosmetically - they look like they've been dragged down the road behind a car and some toddlers have been let loose on the tweeter domes :-/
Despite not being able to refuse the offer (it was take them all, or not at all!) I do not have the room in my house for 10 K series speakers! I would like to b**** the poorer units over for the best drivers ultimately preserving the nicest pair of K's and K2s. Then replace caps and run through the list of other well known upgrades / mods. As I understand it, the paper tweets that come with the Ks are inferior to the K2 DT-3s but the Alnico mid in the K's is superior to the K2 mid. I'm not worried about the majority of cosmetic stuff for now, it's mostly functionality.... So:
K's: bypass/remove Lpads, swap tweeters for DT-3s, recap, rewire, add decent 4mm posts, remove wadding, line cabs, dope bass / mids, seal cabs properly
K2's: swap mids for K Alnico mids, recap, rewire, add decent 4mm posts, remove wadding, line cabs, dope mids (not sure on bass as it's already covered in a coating), seal cabs properly
The vast majority of this I am able to do, and I've been reading through the many many threads here, but I have a couple of questions for those in the know or who have completed these mods and know what's what:
1. Which Bison compound is used? I can find reference to both the car mirror stuff and the kit stuff in a tin. They seem quite different products!
2. Does anyone have a photo of the Bison compound once 'wormed' round / drizzled down to the cap? (most the tinypic links are shot). It seems to me that there could be quite a variation on amount depending on user [in]experience and I don't want to screw it up.
3. Does anyone have a photo of the cab once steel lined? (again, most pic links are shot). I'm trying to get an idea of how completely edge to edge the coverage is. Are we talking do your best but some gaps are ok, or it MUST be edge to edge?
4. I was toying with the idea of using acrylic to line the K2 cabs just because of ease of cutting, it's not going to be as easy as with the Ks as the back is sealed... I read acrylic can be used - is this a waste of time / should I persevere with steel? That baffle is going to be interesting!
5. Can someone recommend a sealant to run round the inside of the cabs for air tightness? I'm not used to infinity bass and didn't realise the air leak thing was so important - will hot glue / liberal PVA suffice?
6. Does anyone know if the K2 bass cone paper caps be sprayed with the Plastidip? I have read they may need to breathe.. but it would be good if it matched the rest of the cone like the end result of the K bass.
7. On paper, the K2 bass goes lower, but I would welcome some input from those with these models - and I do not know how the doping will affect this - would you guys also swap the K bass to the K2 or is it worth keeping? Apart from the cab design, that will be the only difference between the two. I don't really subscribe to "on paper", I only care what the end result is.
I think that's it for now, I might have to ask other things as issues arise! Sorry if this is yet another Goodmans Magnum thread, but its pointless to necro the others.
Goodman's Magnum K series MEGA collection... Mod advice
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Goodman's Magnum K series MEGA collection... Mod advice
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- Lindsayt (Wed Jun 14, 2023 4:57 pm)
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Re: Goodman's Magnum K series MEGA collection... Mod advice
Wow you've asked a lot of questions.
I've just converted the garage from a dump to my workshop , I should be able to get some photos of my definitive wharfedale dovedales interior in a few days.
Bison is a brand (Google it ) I am of the opinion you can use any contact glue
Your cabs are well built , the only sealent I use is between drivers and cab and I use blue tack for it ease of deconstructing
I'm using a combination of steel and 15 mm acrylic .
Plastidip covers the dust cover . Remember doping is an alternative to a crossover , not in my opinion a compliment
I've just converted the garage from a dump to my workshop , I should be able to get some photos of my definitive wharfedale dovedales interior in a few days.
Bison is a brand (Google it ) I am of the opinion you can use any contact glue
Your cabs are well built , the only sealent I use is between drivers and cab and I use blue tack for it ease of deconstructing
I'm using a combination of steel and 15 mm acrylic .
Plastidip covers the dust cover . Remember doping is an alternative to a crossover , not in my opinion a compliment
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- Lindsayt (Wed Jun 14, 2023 4:57 pm)
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Re: Goodman's Magnum K series MEGA collection... Mod advice
I can only answer 5.
I wouldn't use hot glue because it needs absolute cleanliness to stick well and I think you will struggle to get it into the inevitable gapes in the joints. A quick curing silicon sealant however will get into the joints and is somewhat more tolerant of less than perfect cleanliness.
I wouldn't use hot glue because it needs absolute cleanliness to stick well and I think you will struggle to get it into the inevitable gapes in the joints. A quick curing silicon sealant however will get into the joints and is somewhat more tolerant of less than perfect cleanliness.
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- Lindsayt (Wed Jun 14, 2023 4:58 pm) • lysergic-skies (Wed Jun 28, 2023 3:20 am)
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Re: Goodman's Magnum K series MEGA collection... Mod advice
Thanks for the replies.
Despite the plethora of info I managed to gather from the older threads, I found myself with a lot of questions about the doping and lining.
That'd be great to see the photos when you get a minute, thanks
Yeah sorry about that, in hindsight it wasn't the "couple of" I said it would beDaniel Quinn wrote: ↑Wed Jun 14, 2023 12:43 pm Wow you've asked a lot of questions.
I've just converted the garage from a dump to my workshop , I should be able to get some photos of my definitive wharfedale dovedales interior in a few days.
Bison is a brand (Google it ) I am of the opinion you can use any contact glue
Your cabs are well built , the only sealent I use is between drivers and cab and I use blue tack for it ease of deconstructing
I'm using a combination of steel and 15 mm acrylic .
Plastidip covers the dust cover . Remember doping is an alternative to a crossover , not in my opinion a compliment
Despite the plethora of info I managed to gather from the older threads, I found myself with a lot of questions about the doping and lining.
That'd be great to see the photos when you get a minute, thanks
That makes sense, thanks.Geoff.R.G wrote: ↑Wed Jun 14, 2023 1:08 pm I can only answer 5.
I wouldn't use hot glue because it needs absolute cleanliness to stick well and I think you will struggle to get it into the inevitable gapes in the joints. A quick curing silicon sealant however will get into the joints and is somewhat more tolerant of less than perfect cleanliness.
No love for the suggested mods? I am interested to know why? What would you do? Recap and re-wire and leave it at that?
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Re: Goodman's Magnum K series MEGA collection... Mod advice
With 5 pairs you have the potential for a good all-matched Atmos AV speaker system.
Any chance of some photos of the various speakers?
For the tattiest pair I'd be tempted to knock up shrouding panels - ie chipboard or plywood sheets attached to the outside of the speakers.
Any chance of some photos of the various speakers?
For the tattiest pair I'd be tempted to knock up shrouding panels - ie chipboard or plywood sheets attached to the outside of the speakers.
Re: Goodman's Magnum K series MEGA collection... Mod advice
Yes, that’s all I’d do. They’re decent speakers and that’s all they should need.lysergic-skies wrote: ↑Wed Jun 14, 2023 1:43 pm No love for the suggested mods? I am interested to know why? What would you do? Recap and re-wire and leave it at that?
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Re: Goodman's Magnum K series MEGA collection... Mod advice
Regarding sound quality, I'm not sure if anyone has been able to carry out a side by side comparison of original vs modded Magnums. The next best thing would be the feedback from those who have modded a pair themselves. Maybe some members can arrange a bake off.
I see that Russ Andrews is now promoting the same crossover removal mod for Spendor BC1s. The current nostalgia for BBC designs means that a set of even tatty BC1s will set you back £300 plus, whereas the Goodmans can still be found for under a third of that.
I like reading about real experiences and learning, so good luck to the OP, and I hope that those with first hand experience of doc mods (continue to) contribute actively to this thread.
I see that Russ Andrews is now promoting the same crossover removal mod for Spendor BC1s. The current nostalgia for BBC designs means that a set of even tatty BC1s will set you back £300 plus, whereas the Goodmans can still be found for under a third of that.
I like reading about real experiences and learning, so good luck to the OP, and I hope that those with first hand experience of doc mods (continue to) contribute actively to this thread.
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Re: Goodman's Magnum K series MEGA collection... Mod advice
Given you've got so many , you can mod one and compare .
I bet you a tenner you don't agree with riat
I bet you a tenner you don't agree with riat
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Re: Goodman's Magnum K series MEGA collection... Mod advice
I would love that, if only I had the room!Lindsayt wrote: ↑Wed Jun 14, 2023 5:04 pm With 5 pairs you have the potential for a good all-matched Atmos AV speaker system.
Any chance of some photos of the various speakers?
For the tattiest pair I'd be tempted to knock up shrouding panels - ie chipboard or plywood sheets attached to the outside of the speakers.
Here's a couple of really crappy pics quickly thrown together: https://ibb.co/album/rf6PJV I need to go out soon so please bear with me and I'll upload more soon. The Ks side by side are the near perfect ones. The K2 is the 'ok' (veneer) but as you can see the drivers are good. The K on it's side is the fish tank one and you can see all the rusty screws and where brackets have been screwed to the bottom and painted around! The really rubbish pic of 4 together is because I cannot move further back in my living room, those are the crap Ks and 'ok' K2s. The badges on the Ks are still there which I'm pleased about. The really rubbish grille with awful fabric is off the tatty set. The rubbish set is at a friends right now and the pristine K2 set is in a cupboard so the kids don't touch them!
Well, I am not opposed to that if we hear from those who have gone through the doc process and it turns out it's best to leave it alone. As previously mentioned, I only care about results. My goal is to make them sound as good as possible
Thanks savvypaul, hopefully we will hear from those who have done this and I can make a decision from there. I'll make sure to post any progress heresavvypaul wrote: ↑Wed Jun 14, 2023 6:43 pm Regarding sound quality, I'm not sure if anyone has been able to carry out a side by side comparison of original vs modded Magnums. The next best thing would be the feedback from those who have modded a pair themselves. Maybe some members can arrange a bake off.
I see that Russ Andrews is now promoting the same crossover removal mod for Spendor BC1s. The current nostalgia for BBC designs means that a set of even tatty BC1s will set you back £300 plus, whereas the Goodmans can still be found for under a third of that.
I like reading about real experiences and learning, so good luck to the OP, and I hope that those with first hand experience of doc mods (continue to) contribute actively to this thread.
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