impedance vs sensitivity

What you are saying initially is pretty common if you think about it... The more drivers, the lower the impedance usually resides.

The BW speakers act closer to being a 4ohm speaker than the 8 ohms they say they are... ex the 802N... Focal speakers too have lows beneath 4 ohms. Tyler units in the past have delved low as well... Even my Silverline Sonata IIIs respond better on some amps 4 ohms taps than their 8's.

Damping rate of the amp can indicate a better fit than mere topology... SS v. Hs. I refer to damping as 'control' of the loudspeakers drivers, preventing them from returning energy to the amp. Generally, lots of watts can overcome it too. Others here can explain this interaction between the amp and speakers far better than myself.

I've noticed this relationship just by how much more low level impact and timberal truth there is, and/or how much more the vol knob gets tweaked upwards to get the same SPL or satisfying sounds. BTW I'm not keen on high levels of Sound pressure, or immense listening levels. So I like an amp which doesn't have to be turned way up to sound good.

Atmasphere

Regardless the rated impedance of the loudspeaker, doesn't the curve of it's impedance linearity play a more important role?

I mean some speakers, my own included profess an impedance level of 8 ohms... but in practice, delve to far lower means in common usage.

From merely the numbers/specs of an amp or a loudspeaker system, can one derive some methodology for pairing amps to speakers, or vice versa?

For instance, with your amplifiers, do you forewarn anyone as to the speakers with which they are not at their best? ....or are there such speakers?

About the only guidelines I've been able to hang my hat on are these... with 250wpc SS power, there aren't too many speakers such an amp won't drive well. ...and conversely, if a tube amp has 100+ wpc, speaker choices are pretty broad too.

The difficulty I've run into has been matching amps and speakers when the power levels of the amps get below 40 or 50 wpc.... or the speakers have exceptionally tall impedance, and a SS amp is the power plant.

The former interests me greatly, the latter not as much, though I thought to include it as the antithesis of the formers train of thought.

Thanks...

Well, thanks very very much, Atmasphere, indeed.

I sort of figured you would go down that path of viability in conjuction with the use of your amps to anothers current speakerage and their intents.

I noted on my own Silverline Snoata IIIs. I foudn better results using the 4 ohm taps off my Dodd 120 wpc mono blocks, than I did the 8 ohm taps.

On the 8's the sound was very 'tipped up' with little bass and it sounded quite thin, but with immense resolution in the upper bandwidth.

Switching to the 4s on a suggestion from another Dodd owner, brought everything into greater balance. More bass, more anturalness, and less accentuation of the upper mids and highs.

I had a similar result with them on a BAT VK 60 using the 8 ohm taps, but never switched to any of the other taps, (4 or 6) as I simply didn't know any better. primarily too, the speakers were rated by the maker at 8 ohms.... SO WHY THEN SWITCH TO A LESSER IMP TAP?

It seemed counter intuitive and perilous to try other taps.

Would you think then, the Sonata IIIs are a 4 ohm spkr vs. 8, or merely less sensitive than the posted numbers suggest?

reportedly, Alan uses first and seconds with this speaker system.

Atmasphere

Thanks much.

I did find it odd that tube amps needed to be set to taps other than the intuitive 8 ohm ones. Which follows my thoughts here and elsewhere, manufacturers suggest numbers they alone are accounting for... unless of course some recognized 3rd party wishes to spec out their product via other testing methods.

Therefore, with that in mind, it seems to me it's a fairly dicey proposition to select speakers and amps by manufacturers spec sheets alone.

in other words, "THINGS LOOK GOOD ON PAPER, YET DIFFER IN PRACTICE A GOOD BIT OF THE TIME."

It sure is a shame that makers of such loftly priced goods cant' be more square shooters on the specs of their porducts using real world measures. Alan had told me these speakers never dropped below 6-7 ohms across their bandwidth, making them easy to drive with nearly any amp of 10wpc or more.

I've also since found out that if one takes the bother to contact the maker/distributer, more insights to actual impedances can be obtained.... and it's suprising considering the contrast between their posted numbers and those gained by a simple phone call.

Are there so many differring sorts of measureing methods that can be used today, which account for makers offering uh, more attractive numbers than may be the actual case?

An impedance curve is far more the better information than is what a speaker does at 1K Hz... and truly the more erstwhile information prospective buyers require.

BTW B&W too said they test and measure their units differently than the majority of other loudspeaker makers do.

In this day and age, especially with pricing being held above the median for exceptional performance producing components, one would think some standards would now be in place and surely adhered to by all the makers, that better correlate to the practical use thereof... and not simply as an aid, or an out for posting their "at best" specs instead.

Not to mention the added light of honesty it would cast onto the industry at large... thereby further increasing it's attraction to the public in general.