[mhennessy]

Hi Robin,

Thanks for the update - and don't worry; that "Celestion" label is easily missed

Taking your info, plus some more recent purchases and other sets that I've seen or fixed since the last update:

• Goodmans (3 bolts): 26 (3 in RP10, 9 in RP18, 6 in RP25, 1 in AM Herald RP30, 1 in Jonster's AM Herald unnumbered - probably RP30, 1 in SW Herald RP31SW, 2 in Marine Herald RP32, 2 in Herald RP35, 1 in Helmsman RP36)
  
• Goodmans (no bolts): 16 (2 in Sovereign RP25, 1 in AM Herald RP30*, 5 in AM Herald RP35, 3 in Helmsman RP36, 3 in VHF Herald RP37, 1 in VHF Herald RP37A, 1 in Hunter RP38)
  
• Celestion (silver frame): 8 (3 in Sovereign RP25, 2 in RP25A, 1 in RP25B, 2 in VHF Herald RP37A)
  
• Celestion (black frame): 5 (4 in Sovereign RP25B, 1 in VHF Herald RP37A)
  
• Elac (large magnet): 3 (VHF Herald RP37A)
  
• Elac (small magnet): 2 (Hunter RP38A)

* The AM Herald RP30 having a no-bolt Goodmans seems a bit anomalous, but this set is incomplete, and it's possibly not the original speaker. The impedance might be a clue - it should be 30 ohms, but so far I've only seen the newer Goodmans in 15 ohm form. More when it arrives...

So this shows up an inconsistency - your RP37A has a Goodmans speaker, which goes against the conclusions so far. This suggests that your speaker might not be the original model - RP37As should have left the factory with Celestion or large-magnet Elacs. But as you seem to prefer the Goodmans to the Celestion, this sounds like a good result

As before, the latest version of the conclusions in light of new data - not only from here, but from service manuals (thanks, Paul!), pictures on websites, etc. Changes in bold:

1. The Goodmans speaker was the "general purpose" model that was used in most models. It is available in two versions: the earlier version had 3 bolts, later ones don't, and it's available in 15 ohm and 30 ohm versions.
   
2. The large magnet Elac was only fitted to RP37A VHF Heralds.
   
3. The Celestions were only fitted to later RP25 Sovereigns and VHF Heralds (perhaps only the RP37A, but more input welcome). Later versions had a black chassis.
   
4. An RP25 might have an early Goodmans with bolts, the later Goodmans sans bolts, or a Celestion! I presume it depends on serial number, along with the usual production variances - trying to drill down further might be going too far
   
5. RP25As and Bs should have the Celestion speaker... There's every chance (but no guarantee) that speakers in the RP25B sets will have a black frame.
   
6. The change from early to late Goodmans speakers that occurred during the life of the RP25 is also seen in the AM Herald RP35 and contemporaries. This change is close to the change from germanium to silicon AM IF panels.
   
7. Finally, the Elac with the small magnet and gold-coloured frame/magnet was fitted to RP38A Hunters, and possibly later models throughout the 1970s (The Sovereign III family (Black Knight, Super Sovereign, etc) used a smaller 5 by 7" speaker, and I've no idea who makes that. From a picture of a Sovereign IV, it looks like an Elac, but it's hard to be sure).

Thanks again,

Mark