Damping Factor Article

Dedicated to those large boxes at one end of the room
Post Reply
JohnG
Old Hand
Posts: 418
Joined: Sat Mar 25, 2017 10:59 am

#1 Damping Factor Article

Post by JohnG »

The Link is to a Article that the forums Speaker Builders with 'time to kill' might like to look into.
I hope there is info available that makes posting it worthwhile.


http://benchmarkmedia.com/blogs/applica ... e=omnisend
chris661
Shed dweller
Posts: 2556
Joined: Mon Feb 22, 2010 7:29 am
Location: Sheffield

#2 Re: Damping Factor Article

Post by chris661 »

Good to see someone run the numbers.
I do recall some people saying that a Zobel filter robs the speaker of "life", and I'm wondering if that's because there would be less output in the high frequencies due to the driver's rising impedance being flattened. A few dB here and there can make quite the difference.

Chris
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#3 Re: Damping Factor Article

Post by IslandPink »

I had a quick run through the article but it didn't look very sophisticated, and it could be accused of being a sales blurb for their cables.
It seems to miss the point that speaker units and their alignments can be under-damped or over-damped. If the amp ( eg. valve amp ) is going to be relatively high output impedance, say 2 ohms, this just adds to the Qes of the speaker parameters. The point being, the choice of drive unit, and loading ( box size, porting, etc ) can be adapted to the output impedance of the amp - it just needs to be included in the software calcs at the start.
"Once you find out ... the Circumstances ; then you can go out"
JamesD
Old Hand
Posts: 997
Joined: Tue Oct 09, 2007 4:26 pm
Location: North Yorkshire

#4 Re: Damping Factor Article

Post by JamesD »

I wrote a response and deleted it as being too harsh - it started as stating the article was "self serving twaddle" and went on from there :)

Its marketing masquerading as technical and it makes as many specific assumptions that it doesn't detail as the myths it purports to debunk...

Its particularly inappropriate here as the assumption made in the article of ideal voltage source behaviour for the amplifier output impedance and the speaker expected signal source impedance do not apply to 90% of the amplifiers we design and discuss in that these are no global feedback tube designs and particularly the SE ones are better modeled as a current source with finite output impedance... something Scott as speaker designer always takes into account and has mentioned here many times.

This is not meant in any way to be criticism of John for posting it as it lets us raise the issue here and discuss it for all our benefit.

James
User avatar
ed
retired
Posts: 5384
Joined: Thu Jun 21, 2007 4:01 pm
Location: yorkshire
Contact:

#5 Re: Damping Factor Article

Post by ed »

+1 to Mark and James....

I went some way to explore this in regard to speaker alignment and loading and demo'd some findings at Owston some time back. The main enlightenment came with the F2 which has v.high o/p impedance which can produce some very bloated bass. I demo'd with a few speakers of increasing loading and the change in bass response was marked...

I'm not sure the results proved anything concrete regarding d/f being good or bad because despite the f2 having high output impedance it can sound superb when coupled with the right speakers....
There's nowhere you can be that isn't where you're meant to be
JohnG
Old Hand
Posts: 418
Joined: Sat Mar 25, 2017 10:59 am

#6 Re: Damping Factor Article

Post by JohnG »

I'm a Crocodile when it comes to Skin Thickness, I'm not feeling any upset by the Replies .
I'm Glad the Article was shown to be Questionable as to the content, if the Intention of the author was to angle for cable sales, he has not escaped this being revealed on Audio Talk.
chris661
Shed dweller
Posts: 2556
Joined: Mon Feb 22, 2010 7:29 am
Location: Sheffield

#7 Re: Damping Factor Article

Post by chris661 »

IslandPink wrote: Wed Jun 10, 2020 10:37 am this just adds to the Qes of the speaker parameters.
True, but there are effects outside of the Thiele-Small range, which I think this article covers fairly well.
I think we should give the writer more credit - it's a much better piece of work than most HiFi manufacturers would put out.

Chris
Post Reply