Damping Factor relevance

**BTB** · 06 June 2006, 12:23 Tuesday

I don't know, opinions vary, I've spoken to some very informed people who seem to think it's not something to get excited about, others very much think it is. But for what it's worth, I also owned that PM 7200 you're talking about...

So I know it's a little "lax" down below...

My Rotels now have a damping factor of 500 and the "tightness" esp. lower frequencies is quite remarkable by comparison. But at the cost of some other things the Marantz did really well...

**Sim reality** · 06 June 2006, 13:25 Tuesday

The differences in the damping factors is like comparing something being 99% efficient and 99.8% effecient at controlling the speakers...

Can you hear it? Probably. Is it worth the extra price? Depends on how obsessive this hobby is to you and what your preferences are... (IE: Sort of like asking if the Ferrari Enzo is really worth that much more then a F430... Or if you rather get a Mercedes Maybach)

**Alaric** · 06 June 2006, 13:26 Tuesday

Ahhh,that Marantz "magic"

Female vocals and horns. My little Marantz has yet to be beat (purely subjective) in my small listening area. It actually handles bass fairly well with efficient speakers , but Natalie Merchant and John Coltrane come alive with my lil' amp. Multi-instrument crescendos give it fits , but I haven't found an amp that equals the high points of the Marantz and provides the headroom and bass control it lacks. For now , I get few opportunities to crank it up loud enough to bring it's shortcomings out. A noticeable improvement in SQ is several thousand dollars out of my budget at the moment , but I annoy the crap out of audio store employees every chance I get- just in case I win the lottery...... :lol: Those who are polite enough not to actually show said annoyance are in for a banner day if that lottery thing works out!!!
Headroom and "punch" are stellar with the RB1080 , but the "sweetness" of the PM7200 in the mids and highs are phenomenal from a $500 amp. My closest audio store is very McIntosh , so most of thier demos are on Big Macs , and the Marantz has a lot of that character in the sound. However , the 1200 watt Mac monoblock has a wee bit more headroom....!!!!!
Anyway , the damping factor/watts thing has some potential to weed out some theories vs. experience issues. There are so many "high end" amps out there I think a little real world clarification is in order and this forum seems to have the people to do it.

**aud19** · 06 June 2006, 13:26 Tuesday

Anything above ~400 is superfluous. Better? Technically yes. Noticeable? Probably not

**Alaric** · 06 June 2006, 13:37 Tuesday

aud19

So watts sufficient to have a DF of 400+ is the point at which other factors come into play?(THD , power supply , etc.) How does this figure into "range"? Meaning the ability to reproduce "tight" bass and carry good depth in the midrange and clear highs? I like the tight , somewhat harsh , sound of Krell and the smoothness of McIntosh. I guess I want the character of valve amps with the precision of transistors-Am I dreaming?

**Sim reality** · 06 June 2006, 14:08 Tuesday

I am guessing at this point...

But logic would reason that DF and Intermodulation Distortion predominate in the lower frequencies where the power demands and resistance of the speaker dips the most and THD, SNR predominate in the higher frequencies...

I read in some articles that most humans actually prefer a little bit of "properly applied" distortion (which I guess is what audiophiles call "voicing") but I doubt you could tell how it works by just single number descripters...

**Alaric** · 06 June 2006, 14:13 Tuesday

This is getting good!

**Boombox** · 06 June 2006, 16:58 Tuesday

Yeh....I spent hours researching this and the conclusion is that high damping factors are good for amps. The RB1070 has a DF of 500, whereas the RB1080 has DF of 1000.

I don't think that my analogy will hit the mark here, but I'll try my best.
The way that i understand the DF is similar to the way a shock absorber responds in a car. The "stiffer" (higher DF) the shocks are the better handling, grip, acceleration and braking one gets from the vehicle. Worn out shocks (low DF) makes a car a danger to society.

The DF is an indication of how well (high DF - good; low DF - poor) an amp can restore a speaker to its equilibrium position resisting its response to an impulse + its (the speaker's) natural resonance. This is crucial because when the next impulse arrives, the speaker cone must be "in theory" stationary (or better said, in equilibrium).

Now here's the bummer....the DF drops to almost 80 (I think 81 in the RB1070 and 89 in the RB1080) at the speaker due to the impedance of the speaker wire. That said, this impressive decay is a function of the length and "quality" of your speaker cable. With that out the way, it is "common knowledge" (yeh..right!!) or stated differently..."it can easily be shown"...(for graduates - don't you just hate that statement)...that when the DF drops to below 10 it becomes audible...!!! 8O

That just makes you want to replace your speaker's internal wiring.....

Regards,

**chrispy35** · 06 June 2006, 17:40 Tuesday

Google dampingfactor.php for a good analysis. Boombox's #'s illustrate things well too...your speaker wire likely has much greater influence on system damping than the output impedance of your amp.

Valve character is due to harmonics isn't it? That's the opposite of precision.

Chris P.

**BTB** · 07 June 2006, 03:25 Wednesday

Nice one Boombox... I understand your analogy just fine!!!

Originally posted by Alaric

I guess I want the character of valve amps with the precision of transistors-Am I dreaming?

Me too!!! Is it an oversimplification to assume that using a valve pre with a transistor power stage would get close to the ideal? Otherwise hybrid amps are also an option? Alaric... Google "Consonance Calaf"... just for an example, or visit the Opera Audio, Consonance website... a chinese brand (and loosely the subject of another post on this forum)... they've got the Calaf integrated amp from their "Forbidden City" range, valve pre stage, transistor power stage
(200w of it)... incidentally, it claims a DF of 1000!! But then again... those darned speaker cables... :W

Anyway, I don't want to seem like I have some special interest in "pimping" these particular products... just heard some of their gear recently and was very impressed (and therefore excited) because it came so close to my ideal.

**soundhound** · 07 June 2006, 06:57 Wednesday

Originally posted by Alaric

So watts sufficient to have a DF of 400+ is the point at which other factors come into play?(THD , power supply , etc.) How does this figure into "range"? Meaning the ability to reproduce "tight" bass and carry good depth in the midrange and clear highs? I like the tight , somewhat harsh , sound of Krell and the smoothness of McIntosh. I guess I want the character of valve amps with the precision of transistors-Am I dreaming?

Not at all Alaric, go find a VTL dealer and take a ride

**Alaric** · 07 June 2006, 08:55 Wednesday

The fog is lifting....

So , Boombox , am I to understand the watts make the cone move appropriately (knew that!) but the damping factor does just that-damps the reaction of the cone? So for ribbon speakers , the damping factor has no relevance? Geez , I wish my brain were bigger.

ops:

**Sim reality** · 07 June 2006, 11:22 Wednesday

Damping factor is actually a misnomer... It does not indicate that the motion of the speaker had been damped.

What is actualy is the factor of the (speaker impedence)/(amp impedence) which gives the efficency that the amp has to control the speaker (IE: the amount of available power used to drive the speakers).

This is more important to maintain microdymanics in the sound coming out (IE: when the voltage of the speaker drops on the big boom of the drum you don't lose the flute playing in the background).

This ratio is why speaker wire actually has a bigger effect on the damping factor when you get to very large damping factors (hence the 400 comment by aud19).

The same idea applies to ribbon speakers except that they react differently under load. (This is where I am not even going to guess at th exact reaction forces because ribbon speakers can react very differently depending if you are using a "capacitance" type of electrostatic [I think that is what it's called] which uses some sort of elastic media to separate the plates which move based on attraction and repulsion or some sort of suspended media that moves based on changes in the electromagentic field)

Anyways, I hope this is:
a) right
b) clear...

Damping Factor relevance

Damping Factor relevance

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