Goodmans Magnum K Refurb and Modification (part 2)

[Daniel Quinn]

Tweeter in room response can vary . so in principle it is not a bad idea to be able to tailor the speaker to the room and personal preference .

[_D_S_J_R_]

The Doc and I are broadly from the 'radiogram' generation, where the ones Doc grew up with were mainly big tall chests with a big speaker low down giving a lovely 'rich tone' and the ones I grew up with tended to be low and wide by and large (think HVM Stereomaster for one of the better ones). ALL of these featured a big, bassy (not necessarily boomy) tone and it's my opinion that people upgrading to a more Hifi grade of system back then, wanted a similar full-on richness. Clear, dynamic treble transparency wasn't order of the day, despite the old 1950's designed Celestion HF1300 being an all time great even today.

So firstly, do you prefer the Magnums with pots fully open? if so, just short them out or remove them as recommended above. If a little padding down is preferred, then the values of the L pad could quite easily be replicated with resistors (one in series and one larger? across the load so the amp sees correct impedance I think). I think it fair to add though, that any extra 'stuff' in series with the drivers will always sap power, if only a little, so more power will be needed to attempt to get over this (I do appreciate the power handling of the magnums isn't great, but you get my drift).

Pics please

[Dr Bunsen Honeydew]

The whole point of a padding resistor is to sap power as when the treble is more efficient or forward of the bass / mid, and no you don't need a L Pad if the resistance is fixed it can just be a series resisitance.

[Tim Catt]

The Doc and I are broadly from the 'radiogram' generation, where the ones Doc grew up with were mainly big tall chests with a big speaker low down giving a lovely 'rich tone' and the ones I grew up with tended to be low and wide by and large (think HVM Stereomaster for one of the better ones). ALL of these featured a big, bassy (not necessarily boomy) tone and it's my opinion that people upgrading to a more Hifi grade of system back then, wanted a similar full-on richness. Clear, dynamic treble transparency wasn't order of the day, despite the old 1950's designed Celestion HF1300 being an all time great even today.

So firstly, do you prefer the Magnums with pots fully open? if so, just short them out or remove them as recommended above. If a little padding down is preferred, then the values of the L pad could quite easily be replicated with resistors (one in series and one larger? across the load so the amp sees correct impedance I think). I think it fair to add though, that any extra 'stuff' in series with the drivers will always sap power, if only a little, so more power will be needed to attempt to get over this (I do appreciate the power handling of the magnums isn't great, but you get my drift).

Pics

The Doc and I are broadly from the 'radiogram' generation, where the ones Doc grew up with were mainly big tall chests with a big speaker low down giving a lovely 'rich tone' and the ones I grew up with tended to be low and wide by and large (think HVM Stereomaster for one of the better ones). ALL of these featured a big, bassy (not necessarily boomy) tone and it's my opinion that people upgrading to a more Hifi grade of system back then, wanted a similar full-on richness. Clear, dynamic treble transparency wasn't order of the day, despite the old 1950's designed Celestion HF1300 being an all time great even today.

So firstly, do you prefer the Magnums with pots fully open? if so, just short them out or remove them as recommended above. If a little padding down is preferred, then the values of the L pad could quite easily be replicated with resistors (one in series and one larger? across the load so the amp sees correct impedance I think). I think it fair to add though, that any extra 'stuff' in series with the drivers will always sap power, if only a little, so more power will be needed to attempt to get over this (I do appreciate the power handling of the magnums isn't great, but you get my drift).

Pics please

Many thanks for the insight into the history of such designs. So what would you credit the lack of desire for transparency to?

Even when fully open the lpads were exerting a noticeable amount of resistance making removal my only option and I'm incredibly pleased with the results!

Pics will follow shoortly

[Tim Catt]

I'm considering, for an experiment, swapping the tweeters in the magnums for the tweeters from a pair of goodmans mezzo sl's to see how the magnums sound. The tweeters in the mezzo's appear to be very well made and physically more substantial than the magnum tweeterss.

Mezzo tweeters measure 5.5 ohms and the magnums 3. Could anyone tell me if this a possible straight swap or explain why if not?

[Dr Bunsen Honeydew]

Are you measuring in circuit or out of circuit.

[Tim Catt]

Out of circuit for both units.

[Dr Bunsen Honeydew]

I have never heard of a 3 ohm tweeter.

Anyway suck it and see if you want to.

[Tim Catt]

I will do. Cheers.

[Tim Catt]

Just a thought doc, but will the crossover roll off the same mid frequencies with the mezzo tweeter as it doeswith the original magnum tweeter? The mezzo is designed to go to lower frequencies.