When and why did the typical floorstanding speaker lose the midrange driver?

[drrdf]

Part of this may be due to the fact that infra-base no longer seems to be popular or fashionable. You cannot get acceptable coverage down to 15 Hz with these modern devices.

[Barry]

Part of this may be due to the fact that infra-base no longer seems to be popular or fashionable. You cannot get acceptable coverage down to 15 Hz with these modern devices.

I seriously doubt you can get 'acceptable coverage down to 15Hz' with any reasonably sized domestic speaker. Most of what you are hearing is usually frequency doubling.

[Lawrence001]

I seriously doubt you can get 'acceptable coverage down to 15Hz' with any reasonably sized domestic speaker. Most of what you are hearing is usually frequency doubling.

Can domestic rooms even handle the note, what's the wavelength?

[Barry]

Can domestic rooms even handle the note, what's the wavelength?

You can certainly reproduce a note whose wavelength is greater than the maximum dimensions of the room - its just that its not a free-space situation. Also the sensitivity of the human ear is very low at those frequencies, so taken with the need to provide a compression wave, and the generally poor efficiency of speakers, an awful lot of power is required.

[drrdf]

I can assure you that it is possible to reproduce audio adequately down to 15 Hz. I have designed speaker instruments which do it perfectly (- 3dB of course). (I am an indentured apprenticeship-served Engineer with a PhD in Electronic Engineering.) The problem is that the physical enclosures are large, and that is the difficulty for most domestic situations in today's modern miniature houses for dwarfs. However, if you have a large enough home that is not a great problem. (It is always the wife which is biggest problem.) The lowest note on a good pipe organ is a 32 foot open pipe and is a C (15 Hz). Real Hi-Fi is all about reproducing the total audio spectrum properly.

[Macca]

I can assure you that it is possible to reproduce audio adequately down to 15 Hz. I have designed speaker instruments which do it perfectly (- 3dB of course). (I am an indentured apprenticeship-served Engineer with a PhD in Electronic Engineering.) The problem is that the physical enclosures are large, and that is the difficulty for most domestic situations in today's modern miniature houses for dwarfs. However, if you have a large enough home that is not a great problem. (It is always the wife which is biggest problem.) The lowest note on a good pipe organ is a 32 foot open pipe and is a C (15 Hz). Real Hi-Fi is all about reproducing the total audio spectrum properly.

I think the point was not that you can't get speakers to do useful 15Hz reproduction, but that hardly any speakers do either currently or from way back when, midrange driver or not.

[drrdf]

Indeed Macca; that was the main reason I was driven to designing and making my own. But as you seem to agree, it can be done. The large size necessary is the limitation. But of course that is why a double bass is so large.

By the way, one of the best ways to extend infra bass is to install the baffle assembly in an outside wall of the room where you wish to listen, with a suitable vent to the outside environment. You must of course protect from inclement weather. This approach produces much superior results to Helmholtz resonating enclosures (reflex enclosures) and labyrinths as the anti-phase problem is completely eliminated, and there is no back pressure whatsoever on the drive units.

[struth]

Taking things to extremes me thinks

[Barry]

Indeed Macca; that was the main reason I was driven to designing and making my own. But as you seem to agree, it can be done. The large size necessary is the limitation. But of course that is why a double bass is so large.

By the way, one of the best ways to extend infra bass is to install the baffle assembly in an outside wall of the room where you wish to listen, with a suitable vent to the outside environment. You must of course protect from inclement weather. This approach produces much superior results to Helmholtz resonating enclosures (reflex enclosures) and labyrinths as the anti-phase problem is completely eliminated, and there is no back pressure whatsoever on the drive units.

That was what I had in mind when I said it could be done, but not in a free space environment. Brüel & Kjær wrote a paper on such a compression wave approach a few years ago. You still need a lot of power though.

[Macca]

Indeed Macca; that was the main reason I was driven to designing and making my own. But as you seem to agree, it can be done. The large size necessary is the limitation. But of course that is why a double bass is so large.

By the way, one of the best ways to extend infra bass is to install the baffle assembly in an outside wall of the room where you wish to listen, with a suitable vent to the outside environment. You must of course protect from inclement weather. This approach produces much superior results to Helmholtz resonating enclosures (reflex enclosures) and labyrinths as the anti-phase problem is completely eliminated, and there is no back pressure whatsoever on the drive units.

I'd be lying if I said I hadn't considered it. More than once. I think it was Paul Messenger did do it with 15'' Tannoys but his only vented to the adjoining room. Probably sufficient though.