measured:lab 13000 vs proline 3000

audiomik wrote: Re: "Without constant monitoring or careful use of voltage limiters it is easy for the amp to pole pate the drivers." Am of the opinion that voltage limiting isn't the answer since the current can be doing some 'nasty' things long before any voltage limiting occurs. A pic of a 'scope image showing a nice clean output voltage from an amplifier with a very distorted current waveform at the same time (Center trace) when driving a 'Speaker: Now with a good set of results for the real load the 'Speaker presents to an Amplifier; then this sort of thing can be predicted. A bit divergent from the OP for this thread but nevertheless relevant to where the discussion has moved to. Mik

think it might be good if I better explain what is happening in the test above.

The Current waveform is not limited in any way by the Amplifier since this would also appear on the Voltage waveform.

The Current distortion is a direct result of the non-linear impedance of the test 'Speaker's voice coil as it moves within the magnet gap.

Now with these effects happening and being different for each 'Speaker/Cab combination; then they will occur at different Voltage drive levels and in different forms and thus be 'handled' differently by different Amplifiers.

Amplifier Power Supplies: so long as they 'hold up' to provide the Output Voltage and Current demanded by the load aren't the main issue here - the ability of the Amplifier design itself to well manage these non-linear loads is more the issue!

So having a good set of parameters for what load is being presented to the Amplifier is very useful in designing the Amplifier in the first place
Otherwise it is to a certain extent guesswork and why some Amplifiers of similar specifications perform differently to others under the same conditions......

As to Voltage limiting - OK as a device of 'last resort' when set sensibly - but a good pair of ears are definitely best!

Mik

All this got me thinking so i took a volt meter and measured the voltage of our biggest amp.

Heh :)

It will be very interesting to see how the whole China situation plays out.  They had been under pressure to let the value of the currency rise, but mainly from America .. and I don think the US has much influence over China as they need loans ...

What people need to remember is this:  China does not buy from Europe, but Europe buys from China.  Every time you buy Chinese made kit, a small part of the UK now bleongs to China, inch by inch ( or even cm by cm ;) ) It may not be obvious, and the financial routes may be complex, but without bilateral trade,  we are simply swapping the country out, but by bit.

What we need is relatively balanced trade, as a net importer we are simply selling the country off in exchange for short-lived goods. The Chinese will own that bit of land forever, long after the plastic tat has gone to the dump.

Even if they don't directly purchase land, but instead make loans back to us, that too has its price.

You just watch what happens when China makes a move on Taiwan ... I'll put money that a small note about loan repayments is made to Obama .. and the US will "decide not to get involved".   With presedential elections in Taiwan withing two weeks and the DPP candidate (Tsai Ing-wen) looking strong .. it could be sooner than you think.

Thats because they have been buying British and US goverments bonds for age's and now essentially own them. Funny how world power goes round in cycles over many millennia. On that note Id like to wish everyone a happy new year!!!!!!!

Nitz V1505 wrote: Thats because they have been buying British and US goverments bonds for age's and now essentially own them. Funny how world power goes round in cycles over many millennia. On that note Id like to wish everyone a happy new year!!!!!!!

http://www.businessinsider.com/who-owns-us-debt-2011-7#china-15
http://www.businessinsider.com/the-gigantic-chinese-trade-deficit-which-nobody-knows-exists-2011-6

OK,i have cleaned this thread up a bit.

Now i want to make this clear...Stick to the facts.

Choose your words respectfully and carefully Gentlemen.

The first person,(and i dont care who it is,even if you are using a pseudonym) who makes any personal remarks about another member is going to get barred.