Damping Factor/ WPC

[TerryO]

.....that's speculation on your part, Terry....McIntosh surely sold a ton of 2105's, and they're still highly sought after.....

Actually it's not speculation, as McIntosh published a statement to that effect, because they were under constant fire from several of the magazines, especially High Fidelity and Stereo Review at the time.

.....and, I'm one of those people, even though I guess I'm just a poor misguided wretch like you referred to earlier ....these Crown K2's I've got are exceptionally tight and crisp, top to bottom....the damping factor of a Crown K2 is >3000 from 10 to 400 hz....is there an amp which has a higher DF than that?....when I'm listening to a system, the LAST thing I'm going to do afterwards is go do math to see if what I heard was possible.....

The K2 is an excellent amp and I've never heard anyone that said different. However, the fact is that a high Damping Factor doesn't make a dime's worth of difference, just as Dick Pierce correctly points out.

Best Regards,
TerryO

 

[mulester7]

Yup, sure are. Crown Studio Reference and Macro Reference sport DF of >20,000. I've seen some other high ones too but don't recall them off hand. Those were sorta hard to forget with that number.

.....20,000 damping factor, wow....that's probably above the limits of hearing any difference, but it would have to be mighty crisp....pro amps by Crown are good stuff, that's for sure....these K2's have a signal/noise of 110....that's in the territory of 8-9 year old McIntosh amp sections.....my two multi-channel Mac amps are 110 and 112 s/n.....

.....anyhow, the K2's put two vintage Mac amps into storage at my house....the 2105 and the 2200....I sold the 2200 to Dokblues in dry-heat, Arizona, and danged if he didn't fall off in the deep end again and sold it for a fartin' Carver setup....YEAH!....boy howdy, I just don't know about them Maggies....oh well, his business, I guess.....

.....Crown K2's, no fan, sealed....do they get hot?....absolutely, but a small plastic fan from Wal-Mart on low, blowing on and across the top will only help in the dissipation of heat....at one time, I stacked three K2's using twelve 2x2x2 stained blocks of wood, and had a 9 inch fan on both sides blowing between different layers of the three....you don't "have" to cool them with a fan at all, but I thought why not make my K2's last longer, just my choice....for the blocks, I ripped a 2x4 down the middle longways to start with, then clipped two inch pieces....then came stain and 24 hours to dry....worked Great.....

.....it took my current multi-channel Mac amps to retire the K2's from full-range....I've now got three, and will keep them for spare amp channels which are great....sorry to turn this into a K2 endorsement, but I think a Great deal of them being used for full range matched with the pre-amp you love....500 at 8, stable at 2, crisp and tight, top to bottom.....

.....oh yeah, this thread's about Damping Factor....ahem, I only know what I've heard from amps at both extremes of damping factor, and I don't put much faith in a page of math telling me I couldn't have heard what I did....good night.....

 

[mulester7]

the fact is that a high Damping Factor doesn't make a dime's worth of difference, just as Dick Pierce correctly points out.

.....TerryO, all I can say is I think it matters, and is noticeable most in the low end, especially if it's extreme in either direction....and, for all I know, Dick Pierce has a genuine tin ear and loves math, a lot....seriously, I couldn't care less what 50 Dick Pierces think using their measuring machines to make hearing conclusions.....we don't know what he hears, nor if it's in any way trustworthy, we only know for sure what's being processed inside ourselves....Dick Pierce for Dogcatcher, let's hear it.....

 

[89grand]

Audio is really weird. It's really the only place where I hear so many stories about the things people think make a difference when science suggests otherwise.

What anyone hears, or believes they hear can never be proven, so you've got people that genuinely believe things like cable elevators, magic pebbles, power wire, etc make a difference. Most of that stuff sounds more like voodoo to me, and I can't hear those types of things, but I can't prove others can't hear it. It really doesn't matter I guess, if people feel they hear the difference, then to them they do regardless if it's real or imagined.

 

[dezmond76]

.....that's speculation on your part, Terry....McIntosh surely sold a ton of 2105's, and they're still highly sought after.....

.....and, I'm one of those people, even though I guess I'm just a poor misguided wretch like you referred to earlier ....these Crown K2's I've got are exceptionally tight and crisp, top to bottom....the damping factor of a Crown K2 is >3000 from 10 to 400 hz....is there an amp which has a higher DF than that?....when I'm listening to a system, the LAST thing I'm going to do afterwards is go do math to see if what I heard was possible.....

I think it all depends on the amps design if damping factor comes in to play. Most of the old timers on here would never crank up a sub with 1500 watt at 20hz, this is where you would hear and see the difference of more cone control at high db's.

 

[TerryO]

I think it all depends on the amps design if damping factor comes in to play. Most of the old timers on here would never crank up a sub with 1500 watt at 20hz, this is where you would hear and see the difference of more cone control at high db's.

Obviously if the amp has a lot of negative feedback it could certainly come into play, although it may not be in a positive manner.

As for the old timers here never cranking up a sub with 1500 watts at 20 Hz, it's equally obvious that you have no idea what you're talking about.

However, I'll try to be fair and let you have your say.

So, what exactly did you see when you did these tests, what was the total duration of each test and what did the measurements show? How many tests were performed in all. What baseline data did you use for your comparisons and how was it obtained? How did the sound of the "control" differ from the DUT?

One other thing, beside the fact that you're being overly presumptuous, you are evidently ignorant of the credentials of a fair number of people "on here" that you refer to as old timers.

TerryO

 

[70salesguy]

Some input from the James B. Lansing Sound Company.

http://www.lansingheritage.org/html/jbl/reference/technical/damping-factor.htm

And some input on the subject from Crown Audio.

http://www.crownaudio.com/pdf/amps/damping_factor.pdf

 

[dezmond76]

Ok, first off , I don't need to prove anything to you Terry, you will obviously defend your low damping factor equipment regardless. Now that being said , I have 3, 18 subs , the older jbl 4645 is very easy to see the difference in the cone movement. The behringer ep2500 and qsc rmx 2450 have similiar damping factors 300-350 , now after I hooked up the crest v1500 there was less movement at the same volume and a lower low end.Almost as if a hpf or crossover was enabled.

 

[whoaru99]

Ok, first off , I don't need to prove anything to you Terry, you will obviously defend your low damping factor equipment regardless. Now that being said , I have 3, 18 subs , the older jbl 4645 is very easy to see the difference in the cone movement. The behringer ep2500 and qsc rmx 2450 have similiar damping factors 300-350 , now after I hooked up the crest v1500 there was less movement at the same volume and a lower low end.Almost as if a hpf or crossover was enabled.

There's no need to defend anything. I personally have amps with DF from 20 (and maybe even lower on a homebrew tube amp) to >1000.

The point is only to dispel myths.

I'm not discounting your observations, only contending that DF is probably not the causal.

 

[motorstereo]

My take on it is df is it's pretty much a meaningless spec. I've had high df amps which are supposed to have better control the multiple woofers in my set up. I quickly found that high df does not necessarily equal better bass. I'm currently running a Mcintosh amp with a low df and I've truly never had better bass.

 

[Soundminded]

The damping factor of an amplifier is the ratio of the load (speaker) impedance to the source (amplifier) impedance. However to that you have to add the impedance of the speaker wire so for longer runs, use heavier gage wire to get a high damping factor. I use No 16 for about 20 to 30 feet and that works fine for my equipment.

Damping factor has to do with the way energy in the moving mass of the speaker, the cone, voice coil, and coil former dissipates its kinetic energy (energy of motion) back through the amplifier. A speaker is actually a linear motor that can act like an electrial generator. It creates a back emf that tries to push back at the amplifier. The lower the combined impedance of the amplifier output stage plus the wire the faster that energy dissipates. The amplifier acts like an electrical shunt. In practical terms this relates to woofers. A low damping factor can create a bass resonance in some speakers. Higher damping factors reduce or elimiate it. In general most solid state amplifiers have high damping factors. Tube amplifiers have lower damping factors. One way to make a solid state amplifier sound more like a tube amp is to insert a 1 or 2 ohm resistor (at least 10 or 20 watts) in series with the speaker. That will reduce damping on a 4 ohm speaker to no more than 1 or 2 and on an 8 ohm speaker to no more than 4 or 8.

 

[westend]

I think it all depends on the amps design if damping factor comes in to play. Most of the old timers on here would never crank up a sub with 1500 watt at 20hz, this is where you would hear and see the difference of more cone control at high db's.

Hey, I resemble that remark.

Ok, first off , I don't need to prove anything to you Terry, you will obviously defend your low damping factor equipment regardless. Now that being said , I have 3, 18 subs , the older jbl 4645 is very easy to see the difference in the cone movement. The behringer ep2500 and qsc rmx 2450 have similiar damping factors 300-350 , now after I hooked up the crest v1500 there was less movement at the same volume and a lower low end.Almost as if a hpf or crossover was enabled.

*goes for Crest to see*

There's no need to defend anything. I personally have amps with DF from 20 (and maybe even lower on a homebrew tube amp) to >1000.

The point is only to dispel myths.

I'm not discounting your observations, only contending that DF is probably not the causal.

I'm with 'ya, never noted big differences from a change in DF, although I wanted to hear it. :yes:
FWIW, I've had amps with DF over 200 (JBL/UREI 6290) and ones with DF of less than 20 (Pass F5) on Altec 15" and all observable cone motion and tonal characteristics were very close.

 

[mulester7]

The damping factor of an amplifier is the ratio of the load (speaker) impedance to the source (amplifier) impedance. However to that you have to add the impedance of the speaker wire so for longer runs, use heavier gage wire to get a high damping factor. I use No 16 for about 20 to 30 feet and that works fine for my equipment.

Damping factor has to do with the way energy in the moving mass of the speaker, the cone, voice coil, and coil former dissipates its kinetic energy (energy of motion) back through the amplifier. A speaker is actually a linear motor that can act like an electrical generator. It creates a back emf that tries to push back at the amplifier. The lower the combined impedance of the amplifier output stage plus the wire the faster that energy dissipates. The amplifier acts like an electrical shunt. In practical terms this relates to woofers. A low damping factor can create a bass resonance in some speakers. Higher damping factors reduce or eliminate it. In general most solid state amplifiers have high damping factors. Tube amplifiers have lower damping factors. One way to make a solid state amplifier sound more like a tube amp is to insert a 1 or 2 ohm resistor (at least 10 or 20 watts) in series with the speaker. That will reduce damping on a 4 ohm speaker to no more than 1 or 2 and on an 8 ohm speaker to no more than 4 or 8.

.....best post of the thread, imo....thank you for not enlightening us with what someone else thinks as your sole message.....

 

[goldear]

As many otherse have already stated here: Damping factor means next to nothing when it comes to the actual sound of the amp. But for that matter, most specifications really don't tell you very much about the sound of an amp; at least so long as they are not trully terrible.

 

[TerryO]

Ok, first off , I don't need to prove anything to you Terry, you will obviously defend your low damping factor equipment regardless. Now that being said , I have 3, 18 subs , the older jbl 4645 is very easy to see the difference in the cone movement. The behringer ep2500 and qsc rmx 2450 have similiar damping factors 300-350 , now after I hooked up the crest v1500 there was less movement at the same volume and a lower low end.Almost as if a hpf or crossover was enabled.

Actually, when you start making statements about what you assume others have, or haven't, done in this area you're already treading on thin ice. As for "my" equipment, you have no idea what I (or anyone else) has used and since you want to make this into some sort of immature pissing contest, it's not unexpected.

However, just to put your mind at ease, I'll mention that for a great deal of the high power subwoofer testing (and destruction) that was done at Adire, a Crown K2 amp was used, although on occasion there were others. The fact that the Crown is nearly indestructible, puts out tremendous amounts of clean power and is consistently reliable were the reasons that it was used, not because of any DF hocus-pocus.

TerryO

 

[Uncle Paul]

I learned something new today reading this thread, and put to rest my misconceptions about the damping factor, and what it means. Thanks all for your knowledge and input.

 

[Vinylcalle]

I overheard some speaker/amplifier designers/technicans talking about damping factor a while back.

They´re take on it was that a high damping factor isn´t allways what will sound best with all speakers. And also that beyond a damping factor of about 70-80 there won´t really be any important diffrence.

 

[Kevin Gong]

Just as Soundminded states, damping factor is the ratio of the load to the source impedance. Back in my electronics class days in the 60's. The goal for good damping factor is 10 or over by all power distribution companies. This means a 10% power loss. But in audio, It has an effect on the sound because the speaker is not linear, thus for all the discussions about whether they are good or bad. A little history. Back when audio was only tubes. The damping was about 2-3 due to the tube always have high plate impedance. Then came the ideal tube call the 300B had low impedance and high power(all 15W). The biggest breakthrough came in 1947 with the Williamson amplifier with a 20db feedback to get the damping factor to about 10 which is the ideal. That was when the audio came of age so to speak. Then came the transistors amp from Japan, using multiple feedback loops drives dampping factor to 100 or more. Along withe high damping, the amp has lower distortion. Kill 2 birds with 1 stone. The amp now looks real good on paper. But amp does not sound "right" because the the speaker is still not linier. This kind of explans why McIntosh amps has a damping factor still at about 10.
My 2 cents,
Kevin

 

[charles 1973]

I had pretty much assumed that DF really didn't mean much untill A recent thread involving tube amps. This fellow was commenting on the fact that no matter which tube amp he used, a little sony reciever sounded much better. He later read the manual on the speakers and it said to use a High quality SS amp with as high a damping factor as practical.

I recently purchased an Good Amp with an 800 DF. My old Fairly good amp had a DF of 100. The better amps bass response is a hair better, but not nearly the 8x better suggested by DF. In fact sometimes the amp with the low DF Gives the bass more weight with 90% of the control. I've a feeling most of that difference has little to do with DF anyway.

As a rule of thumb I'm thinking a DF of over 60 should be fine for most speakers. The low DF of Tube amps however may be an Issue with the wrong speakers. Thats one reason I prefer using tubes at the source or a tube preamp and stay SS with the power amp.

 

[kevzep]

I have Crown macrotech 5002VZ sometimes but mainly QSC powerlite 4.0 on my 15inch L'acousatic subs....I usually have the crowns after I have repaired or serviced them (our sound company has 72 of them)
The Crown has a damping factor of 1000, and the QSC has a damping factor of 500.
I have noticed the QSC has a more rounded and resonant bass sound, whereas the Crown has a more linear and even bass sound which sounds like it has more sustain, now the interesting part is even though these amplifiers have the same sensitivity, I always seem to end up running the Crown about 2-3db hotter than the QSC for what sounds to me like a much cleaner and very musical bass response.....
This seems to fit with what some guys have been posting here......I found it quite interesting to read this thread, Ive never thought about damping factor before, but now I have.......:thmbsp: