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Large infinite baffle speakers?

There is another tradeoff of course in that the higher you run the mid the closer the tweeter has to be placed to the mid to prevent phase cancellations.

That is a very good point. I suspect it is actually the key thing I learned when trying to use a pair of Decca ribbon tweeters as super-tweeters with my Tannoys. Just didn’t work to my ears, though I’d argue I did far better than Tannoy’s own attempts!
 
Lots of three-way speakers of that form-factor, e.g. AR 3a, Ditton 44 etc. It really surprises me there hasn’t been any revival as it is one of the most sensible ways to build a loudspeaker IMO, and a lovely timeless/classic form-factor aesthetically too.

PS If I ever wanted to try designing a speaker myself this would likely be my starting point. I’d just try to use modern driver advances to run the mid unit over a wider range so it wasn’t too far away conceptually from a full-range driver with a super-tweeter and sub, i.e. get the crossover points as far away from the critical midband as possible. Again it really surprises me no one has tried it.
@yuckyamson have been persistently trying to get me to design a Yam 1000-M tribute with modern drivers. The criteria are high-ish sensitivity (no less than 90dB/w/2.83V), easy load (nominally 8R), and dome midrange (of course). Except for the ATC mid, which is not generally available to the DIY community, there is bugger-all choice.

There are, of course, more conventional (cone) drivers to do mid duties, but the wider-bandwidth ones tend to be less sensitive (they are generally designed to be mid-woofers) or they are less linear.

The woofer and tweeter choices are less troublesome.
 
The Radford M90 was a very clever sealed box design. It’s made from plywood and the two smaller drivers sit in their own compartment whilst the bass unit (12”) sits on its own in about ¾ of the cabinet volume.
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Are those Goodmans drivers, the bass and mid?
 
Yes, originally all the drivers would have been Goodman’s but the tweeters have been replaced.

I have Goodwoods which have the same 12” bass driver and I thought the same mid. They have a wider and shallower cabinet and the mid/tweeter are horizontally aligned, but IIRC only the tweeter has its own compartment.

So we should add Goodmans Goodwood to the list, and Magnums.
 
Linn Ninka
Linn Isobarik
Linn Keltik
Linn Kaber
Linn Keilidh
I’m don’t actually know how big the OP’s speakers are for comparison, but I’ve owned four out of the five you list there, and still do own three of them… in the right system and location, they can have fantastically deep and tight bass… get it wrong and they can be a disaster, but I’ve generally got them right… yes even Kabers can do extended, tight bass.
 
I have Goodwoods which have the same 12” bass driver and I thought the same mid. They have a wider and shallower cabinet and the mid/tweeter are horizontally aligned, but IIRC only the tweeter has its own compartment.

So we should add Goodmans Goodwood to the list, and Magnums.
... And Magisters, the biggest of all the Goodmans (in terms of woofer size at least).

This was my pair:

1185453-7e8f0a85-goodmans-magister-speakers.jpg


45788297984_d9c3a36a63_o.jpg
 
I remember the brochure stating a full octave of bass extension for the Activ version. That could only come from a boost in the Activ filters.
Indeed, this is the case for quite a few Linn speakers. It works extremely effectively though and doesn’t cause an over excursion of the drivers at any realistic listening level.
 
One can always shove some old socks into the port of any reflex loaded design and making it a closed box. Easily reverted if the result isn't an improvement.
 
I've got some NHT Evolutions, a slightly different design than a lot of speakers being actively bi-amped with ther own highpass crossover, better than the old 801's and in some regards the JBL Array's too, dynamic live sound, they work in a smaller room and despite their size the satin grey finish helps them blend into the room. The importer was selling a pair on here for peanuts a while back, shame no one got them.
 
These can even be run active with a Linn Exaktbox, but you'll be lucky to find a pair that has got functioning mid drivers, but they are repairable / replaceable.

I have a working pair of HB3. IIRC only the very last ones had provision to go active. Of course one could remove the crossover and fit an extra two sets of speaker terminals to an earlier pair I guess but the last ones also had the tweeter and mid drivers swapped round ie mid at top and tweeter underneath it.
 
I have a working pair of HB3. IIRC only the very last ones had provision to go active. Of course one could remove the crossover and fit an extra two sets of speaker terminals to an earlier pair I guess but the last ones also had the tweeter and mid drivers swapped round ie mid at top and tweeter underneath it.
I was hunting for a pair of hb3s for exactly this experiment a few years back. Figured I would get some cheap minidsp thing and cheap amps and give it a shot.

Two things derailed this:

1) nearly impossible to find used hb3s in North america. Despite there amazing value offering at the time they didn't sell well in Canada, likely because it was during the time when large standmounts were becoming less fashionable compared to the now de regeur slim floorstanders, and

2) I emailed Peter Comeau, the original designer, and asked him about doing this. He immediately told me that one couldn't simply plug in the same values from the passive filters and expect it to work. I am not technical so I didn't really catch what he was saying but he seemed very confident that finding the right values was a new design exercise in and of itself.

Thus ended the fantasy.
 
I was hunting for a pair of hb3s for exactly this experiment a few years back. Figured I would get some cheap minidsp thing and cheap amps and give it a shot.

Two things derailed this:

1) nearly impossible to find used hb3s in North america. Despite there amazing value offering at the time they didn't sell well in Canada, likely because it was during the time when large standmounts were becoming less fashionable compared to the now de regeur slim floorstanders, and

2) I emailed Peter Comeau, the original designer, and asked him about doing this. He immediately told me that one couldn't simply plug in the same values from the passive filters and expect it to work. I am not technical so I didn't really catch what he was saying but he seemed very confident that finding the right values was a new design exercise in and of itself.

Thus ended the fantasy.

Point 2 is certainly correct yes.
 


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