Large infinite baffle speakers?

[Robert]

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!

A nice 5" Kef Uni-Q paired with a 12" woofer in a closed box design. Needs to be done.

 

[sunbeamgls]

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.

Yes, the passive crossover needs to be removed and extra terminals added. Its a very simple box inside, so its an easy enough job. The available Exakt filters are for the Mk1 version. Happy to create filters for the MkII if anyone needs them

 

[sunbeamgls]

A nice 5" Kef Uni-Q paired with a 12" woofer in a closed box design. Needs to be done.

You're almost describing Andrew Jones' Adante range for ELAC, but they use multiple smaller woofers rather than one big one, and an interesting full size passive radiator in a strange sealed / not ported kind of design.

 

[Arkless Electronics]

The KEF R105/3's I have possess 2 x 8" woofers each in a sealed box at top and bottom of the speaker which fire into a central cavity which then has a very wide port to the outside world. KEF's "coupled cavity" bass loading method.
Unusual but seems to work. These crossover to a D' Apolito arrangement of 5" (ish) lower mid drivers (so 2 of) with the Uni-Q upper mid and treble driver in the middle. 114dB max SPL

 

[RJohan]

The KEF R105/3's I have possess 2 x 8" woofers each in a sealed box at top and bottom of the speaker which fire into a central cavity which then has a very wide port to the outside world. KEF's "coupled cavity" bass loading method.
Unusual but seems to work. These crossover to a D' Apolito arrangement of 5" (ish) lower mid drivers (so 2 of) with the Uni-Q upper mid and treble driver in the middle. 114dB max SPL

Also known as fourth order bandpass. Through the years it has been very popular in car stereo and among DIY'ers in general. It was a long time since I saw it in a commercial design, though.

 

[RichShortland]

Here's my sealed / infinite baffle speakers. They are Hales Revelation IIIs, a US design. They have a 10" bass, with the mid and tweeter all in their own separate internal spaces. Think the mid/bass are Peerless (?). I bought them in a very sorry state, and refurbed them using a slight sparkle back vinyl wrap over the nasty tatty dark veneer, repainted the (thick solid) front baffles, and fitted the spiked feet. They have the receivers for some grills so I'll make up some shaped grills, perhaps with cloth in a bright colour at some point.
They are very heavy and quite massive visually, but work really well up against the wall which helps with the domestic harmony...
Originally they had metal dome tweeters (one of which was damaged) so I upgraded them with a slightly better fabric dome which has very nicely lifted the top end performance.
What I love about these is the quality as well as the quantity of the bass performance, and the separation and cohesion achieved throughout, which I think is definitely a symptom of the sealed design. Sonically they disappear quite well.

 

[Chris]

Robert’s own AR22t used a BMR to cover most of the audio band with a refoamed AR 8 incher for the bass only and a vifa supertweeter above 16kHz. Whatever happened to BMR designs ?

 

[PerF]

The BMR used in Ovators, RS10 and some Cambridge, maybe others ?

 

[Colin L]

Ive always wondered how you can accommodate an infinite baffle speaker domestically.
Like, don't you need a really, really, really large room

 

[Arkless Electronics]

Ideally you use the room as the baffle! A pair of Tannoy DC's set into the wall and simply open at the back, "venting" into the room behind... Add a pair of tweeters close to the backs of the units in the other room and there you have it... a multi-room installation

 

[Mike P]

I've a vague recollection of a Gilbert Briggs design for brick built speaker enclosures built into the walls of your house. Or did I just dream that up?

 

[yuckyamson]

Robert’s own AR22t used a BMR to cover most of the audio band with a refoamed AR 8 incher for the bass only and a vifa supertweeter above 16kHz. Whatever happened to BMR designs ?

the problem with BMR's is their sensitivity. While they have great wide frequency response and good dispersion, it is very difficult to find one that is greater than 83/84 dB in sensitivity.

While power is readily available today in large quantities thanks to Class D, as I've learned from @James , you have to know what you're trying to do with a loudspeaker when you have a design brief. If the idea is to have a speaker that is low in sensitivity (like an LS3/5a, for example), then fine. But if you want something that hits 90 dB and allows for partnering with lower-powered Class A amps, then a BMR is tough to integrate.