Vintage speaker enclosures - help needed

[OldRecordLover]

I inherited a pair of speaker enclosures, custom-made by a relative in the early/mid 1970s. This photo of the crossover units shows what the drivers are.

https://theartofsound.net/forum/attachment.php?attachmentid=30425&d=1655714260

On the back of each speaker there's a small cream knob which has two positions only - it's under the crossover wiring loom in the second photo.

On the back of one speaker, there's a larger clear dial which has four positions.

https://theartofsound.net/forum/attachment.php?attachmentid=30426&d=1655714270

I tried the knobs in different combinations and there was some difference to the tone but when I turned up the volume, the amp started misbehaving (power light flashed on/off, one channel stopped working temporarily). It's an old backup amp (Denon PMA-355UK) and these problems might be unrelated to the speaker controls - just coincidence.

I have no idea what the different knobs might do - can anyone offer suggestions/advice?

[Macca]

I inherited a pair of speaker enclosures, custom-made by a relative in the early/mid 1970s. This photo of the crossover units shows what the drivers are.

https://theartofsound.net/forum/attachment.php?attachmentid=30425&d=1655714260


petty sure these dials are to adjust relative levels of each driver. As for the rest I don't know. There may be a fault in the crossover on one of the speakers that is causing the amplifier to go into protection. Any chance we can have some more pictures?

[OldRecordLover]

petty sure these dials are to adjust relative levels of each driver. As for the rest I don't know. There may be a fault in the crossover on one of the speakers that is causing the amplifier to go into protection. Any chance we can have some more pictures?

Thank you. I know what the controls on the crossover units do - it's the knobs on the back that are the mystery. I can post photos of the front of the speakers (I don't think that'd help, though) but short of removing the backs, I'm not sure what other photos would be useful?

[Macca]

Thank you. I know what the controls on the crossover units do - it's the knobs on the back that are the mystery. I can post photos of the front of the speakers (I don't think that'd help, though) but short of removing the backs, I'm not sure what other photos would be useful?

Need to see where all the wires go, that's the only way of working it out.

[snowman_al]

You might find this interesting:- https://www.voxac100.org.uk/midax.htm

You will have to remove the backs to find out any more, they are clearly very well made, but we all do 'it' differently.

I suspect you need to look at ebay prices (for the Trebax 100 and Midax 650) to get an idea of value... There are many WB Stentorian models so have a look inside.

Alan

[OldRecordLover]

You might find this interesting:- https://www.voxac100.org.uk/midax.htm

You will have to remove the backs to find out any more, they are clearly very well made, but we all do 'it' differently.

I suspect you need to look at ebay prices (for the Trebax 100 and Midax 650) to get an idea of value... There are many WB Stentorian models so have a look inside.

Alan

Thanks, Alan - that's an interesting page. I have some original paperwork for the speakers (ppssibly made by "A Davies & Co, North London") which includes one of those "Blue Dot" leaflets pictured on the Vox site.

It looks like I'll need to remove the backs at some point but in the meantime, maybe there'll be some educated guesses about the purpose of those two mystery dials...

[struth]

some of the whiteley's bass drivers had different taps for impedence so im guessing one at least is for that. probably 2 way.

[snowman_al]

We do not know what type / make the bass driver is yet.
The Stentorian knob has the script, ''Cone Tweeter'' round the dial.
Even more reason to get the back off...

[Macca]

God only knows what's going on in there.

[Barry]

Thanks, Alan - that's an interesting page. I have some original paperwork for the speakers (ppssibly made by "A Davies & Co, North London") which includes one of those "Blue Dot" leaflets pictured on the Vox site.




I used to have some literature by A. Davies on their loudspeaker enclosure cabinets. They were designed to use a variety of drive units from the, then, major driver maunufactures: Wharfedale, Goodmans and Stentorian, as well as 'exotica' such as the Kelly ribbon and Shackman electrostatic treble units.

Unfortunately, during a clearout a couple of months ago of a mass of hi-fi magazines and audio component manufacture's leaflets and literature, I threw out the A. Davies stuff. :doh: