What Damping factor 250 Vs 135?
Posted by: Noel on 11 July 2003
Just curious, I've never enquired too deeply about the specs before. It's usually the wattage and current capability that get bandied about, but does anyone know the damping factor for an 'Olive' early 90's Naim 250, and how that compares to a pair of 135's? Are these kind of figures, slew rates etc., published anywhere. (I can understand if they're not as things can quickly descend into 'Product A is better than Product B because....')
Noel.
Posted on: 11 July 2003 by Andrew L. Weekes
Date: April 26, 1999 01:58 AM
Author: julian vereker
Subject: Just a number
Damping factor is just a rather poor way of describing the output
impedance of the amplifier.
The figure is derived from the impedance of the speaker divided by the
ouput impedance of the amplifier - since most speaker impedances vary
by at least 10 to 1 over their bandwidth, particularly in the bass
region where 'damping factor' is supposed to be useful - I supect that
it is a very unhelpful & misleading number.
julian
Naim do publish a performance criteria for their amplifiers which is probably one of the tightest anywhere, it just doesn't include any actual numbers, since these are often meaningless.
Andy.
[This message was edited by Andrew L. Weekes on FRIDAY 11 July 2003 at 14:46.]
Posted on: 11 July 2003 by Paul Ranson
Damping factor is meaningless. Naim amps (certainly of the Olive class) have a resistor in series with the output, this will dominate the output impedance of the amp. In the general case the impedance of the PCB tracks, wiring, socketry, speaker cables add up to rather more than the output impedance of the amp measured at the feedback take off point. And then add in the speaker components....
FWIW I'd expect the 250 and 135 to measure the same for this parameter.
Paul
Posted on: 11 July 2003 by Noel
Thanks for the replies Andy and Paul. I've always liked what I feel is the slightly 'easier, more relaxed' sound of the 250 compared to the 135s using SBLs. Now I use Arcs, the grip of the 135s becomes more attractive. I then started wondering about why they sound different. As I originally alluded, statistics and measurements can be easily misused. Obviously listening is the key.......Anybody want to lend me a pair of 135's????
