Recommended Power Amp watts vs Speaker Watt power handling ability

@ bombaywalla, Thanks, I checked out the other thread, too. Good info.

Lots of attention was given to high-end distortion. So I understand that distortion sends harsh high signals to the tweeter and can fry it fast. But I listen to music with lots of bass with levels averaging around 30Hz. I get the impression that Ohms can dip to 2 or 1 with deep bass notes.  

I thought watts doubled as Ohms decreased. The Primare does 250 watts @ 8 Ohms but only 400 watts @ 4 Ohms (I didn't see measurements for lesser Ohms). So it seems the "double watts with lesser Ohms" theory can't be applied. Do I need to worry when listening to music at average levels (50 - 66dBA according to my digital sound level meter)? Is my reasoning erroneous?

mewsickbuff, good to read that you found the info in the other thread informative.

I get the impression that Ohms can dip to 2 or 1 with deep bass notes.

this is not necessary for every speaker. it depends on the speaker design & one needs to see the impedance & phase plots to determine just how low the impedance is in the bass region for a particular speaker. I could not find any imp & ph plots for your MA Gold 300 speaker so i don’t know whether or not your speaker’s imp is low in the bass region....
In general, there are many speakers in the market that do dip in the low Ohms in the bass region - finding a speaker (that is touted to be 8 Ohms nominal) to be 3-4 Ohms in the bass region is not uncommon.

I thought watts doubled as Ohms decreased.

sorry to burst your bubble but they often don’t. Power doubling with each halving of speaker impedance is a huge function of the amp’s power supply - it requires huge power transformers, large heatsinks, many more matched output transistors, excellent design to dissipate the heat otherwise components begin to fail due to exposure to heat & an excellent grounding scheme so that many points in the circuit see a low impedance path to ground. Such amps are very expensive - we’re often talking $10,000 & more. Plus, they are few & far between i.e. not every manuf makes them. Such amps are also very heavy - in excess of 100lbs due to the large transformers heatsinks.

The Primare does 250 watts @ 8 Ohms but only 400 watts @ 4 Ohms (I didn’t see measurements for lesser Ohms). So it seems the "double watts with lesser Ohms" theory can’t be applied.

indeed correct for the Primare. The fact that power rating for below 4 Ohms is not given would seem to imply that the amp should not be used for very low impedance speakers as it could cause (1) excessive heating due to the amp’s output stage trying to output a lot of current to drive the speaker &/or (2) the amp could go unstable as low speaker impedances are often characterized by having a fair amount of capacitance as part of the impedance.

Do I need to worry when listening to music at average levels (50 - 66dBA according to my digital sound level meter)?

according to my research the Nat’l Inst of Occ Safety & Health says that a sound of 85dBA can be listened to for 8 hrs a day. Using this metric I believe that you should have no issues with your Primare driving your Gold 300 speakers at 50-65dBA levels. I.E. your Primare will be outputting only a few watts to generate 50-65dBA sound. I’m sure that you will have peaks that will exceed 50-65dBA but since they are peaks they will last for very short times...

Highly informative. Thanks much!

Amp clipping is the danger

The best amps do  double. Something like big Krells or CJ 350 or the large Musical Fidelities. But these are expensive and heavy. Never depend one of the meters as they lag behind. The LEDs work well but I think they are out of fashion.