Try to put 1-2 ohms in series, or a 10 meter 0.01mm2 cable in series with the sub.
Thats what I like most for subs.
I went even longer than this. i have >200 ohms, output impedance from an experiment amp, and thats the best amp i tried so far!!
Read this!!!
Joe Rasmussen "Trans-Amp" - 40 Watt Transconductance "Current Amplifier"
Thats what I like most for subs.
I went even longer than this. i have >200 ohms, output impedance from an experiment amp, and thats the best amp i tried so far!!
Read this!!!
Joe Rasmussen "Trans-Amp" - 40 Watt Transconductance "Current Amplifier"
Everyone can try a Couples of ohms in series with the woofer. And get oceaner morse distortion Free bass... just do it...
Regarding the benefits of current drive or transconductance amplifier please loock on the thread i reffered to.
Joe Rasmussen is explaining this topic and he also mention that "damping factor" is nothing to strive for.
It´s a myth... it´s "busted" and you can bust it yourself by apply a resistance in series with the woofer if you want to.
Joe Rasmussen is explaining this topic and he also mention that "damping factor" is nothing to strive for.
It´s a myth... it´s "busted" and you can bust it yourself by apply a resistance in series with the woofer if you want to.
Quote from scottjopplin link above, regarding resistance between amp and speaker:
"The results of using modified impedance can be very satisfying, allowing a useful extension of the bottom end. My own speakers are driven from a 2 ohm amplifier impedance, and there is no boominess or other unpleasantness, but a worthwhile improvement in bass response is quite noticeable."
Rod Elliott (ESP)
"The results of using modified impedance can be very satisfying, allowing a useful extension of the bottom end. My own speakers are driven from a 2 ohm amplifier impedance, and there is no boominess or other unpleasantness, but a worthwhile improvement in bass response is quite noticeable."
Rod Elliott (ESP)
I do not have such advanced knowledge to enter into any controversy regarding this issue, but I read completely - at its peak - the link you cite, and as I mentioned before, (because of the coming twentieth century) it was very debated by people who seem to live up to the debate, and very controversial.
Anyway I will continue with my anti-Flood concepts, and I will never connect a series resistor to increase the output impedance, that energy that falls into the resistance is wasted (I have never noticed audible improvements) and I am one of those who always prefer a power reserve in the amplifier.
This went very badly translated. I'm sorry
Anyway I will continue with my anti-Flood concepts, and I will never connect a series resistor to increase the output impedance, that energy that falls into the resistance is wasted (I have never noticed audible improvements) and I am one of those who always prefer a power reserve in the amplifier.
This went very badly translated. I'm sorry
Increasing the output impedance in such a way is a fudge when using the wrong speaker with the wrong amp.
Maybe the wheel was not such an important discovery after all ?
Technically, the damping factor of a system refers to the ratio of nominal loudspeaker impedance to the total impedance driving it (amplifier and speaker cable). In practice, damping is the ability of the amplifier to control speaker motion once signal has stopped. A high damping factor means that the amplifier’s impedance can absorb the electricity generated by speaker coil motion, stopping the speaker’s vibration.
What is "Damping Factor"? | Sweetwater
Oops, there's an error here I didn't see before. Doubling the wire diameter (from 4mm to 8mm) increases the cross-section area by 4 times, and thus reduces the resistance by 1/4. This is indeed equivalent of a change of 6 AWG, but you only need to go down 3 AWG to halve the resistance (increasing the diameter by 1.414 will double the area).
Here's a chart:
AWG American Wire Gauge Diameter and Resistance
Of course, the big discussion and what the OP keeps asking is whether a change in damping factor greater than 20 is audible. I'd suggest the OP to change the longer cable with 16 AWG lamp cord (this would definitely lower the damping factor) and listen to how much difference there is versus a lower resistance cable.
From what I’ve read, it seems the general consensus is that once the dampening factor is over a certain amount, it becomes inaudible and so insignificant it’s not worth mentioning.
All I wanted to make sure is that my system that I’m planning on building is over that threshold so not worth worrying about..
Not talking about amplifier dampening factor but the overall factor once speaker wire and speaker are introduced.
But the point of the post was for 2 reasons.
1. Is there any cable with a lower resistance than the one I have but the same thickness. (4mm). As 4mm is the thickness limit for under my carpet.(now a mute point)
2. To discuss the unresolved question of. What is the actual audible limit?
They may have been someone on here who noticed a difference between a calculated 20 to 50 or 50 to 100.
Or it may be inaudible.
This is not to do with DB loss. Which is a difference subject. It’s to do with sound quality and the way the amplifier has control of the speaker cone once the signal has stopped.
I have no clue as to how far to go with this. Most people think that it’s not worth worrying about, but as we can see from how many reply’s this thread has generated, The subject is either not very well understood as a whole and is more complicated than what I think, or people are divided on what matters and what doesn’t.
I think a bit of both.
All I wanted to make sure is that my system that I’m planning on building is over that threshold so not worth worrying about..
Not talking about amplifier dampening factor but the overall factor once speaker wire and speaker are introduced.
But the point of the post was for 2 reasons.
1. Is there any cable with a lower resistance than the one I have but the same thickness. (4mm). As 4mm is the thickness limit for under my carpet.(now a mute point)
2. To discuss the unresolved question of. What is the actual audible limit?
They may have been someone on here who noticed a difference between a calculated 20 to 50 or 50 to 100.
Or it may be inaudible.
This is not to do with DB loss. Which is a difference subject. It’s to do with sound quality and the way the amplifier has control of the speaker cone once the signal has stopped.
I have no clue as to how far to go with this. Most people think that it’s not worth worrying about, but as we can see from how many reply’s this thread has generated, The subject is either not very well understood as a whole and is more complicated than what I think, or people are divided on what matters and what doesn’t.
I think a bit of both.
Sorry.... i dont want to upset anyone.
But let me explain in short the physics, this forum is primarily for education isn´t it?
Regarding really high output impedance, trans conductance or current drive. I have just built some after the schematics here:
Joe Rasmussen "Trans-Amp" - 40 Watt Transconductance "Current Amplifier"
If we listen to the theory that extremely LOW output impedance is "the best" thing... How come that 270 ohms output impedance really outperformed my Bryston 4B amplifier in my active driven hifi system? I have had several listening sessions here confirming that the woofers play deeper, more powerful, and less colored?
This is how it works.
The force F acting upon the membrane comes from the current I of the voice coil wire length L that moves in the magnetic gap adn the field B with the formula F= B*I*L
L and is fixed parameters defined by the construction of the magnetic drive system. So we see that the force F is directly proportional to I current. The speaker is by it´s construction CURRENT DRIVEN and NOT voltage driven. The transconductance amplifier transforms the voltage signal (nice music hopefully) to a current! That we by definition wanted right? This works well in an active loudspeaker system where no other passive crossovers is involved. Thats why this construction isn´t very common, and this is not for every one since you have to do some adjustments to get it work properly (oscillation). The side effect is the you can reduce the distortion of the woofer from 20% to 2%, that means with factor 10 . That is coloration we are talking about, that is smearing out details and ADDING harmonics that is not present in the music signal from the beginning. So where does this distortion comes from and how is it reduced by a strange amplifier topology that none uses?
When the signal current induces a magnetic field around the voice coil, eddy currents in the pole pieces is generated and creates voice coil position impedance variations. Also the voice coil current heats up the copper which in turn increases the resistance and adds compression. And the voice coil itself has 6 ohms resistance when its cold, after some minutes it reaches 6,2 ohms.... A current amplifier will correct this!
It will continue to move the speaker even if the resistance is changing to 10ohm!
If you have a cable with 0.0001 ohm or 3 ohms it will play exactly the same with current drive! The other benefits I can mention another day.
But let me explain in short the physics, this forum is primarily for education isn´t it?
Regarding really high output impedance, trans conductance or current drive. I have just built some after the schematics here:
Joe Rasmussen "Trans-Amp" - 40 Watt Transconductance "Current Amplifier"
If we listen to the theory that extremely LOW output impedance is "the best" thing... How come that 270 ohms output impedance really outperformed my Bryston 4B amplifier in my active driven hifi system? I have had several listening sessions here confirming that the woofers play deeper, more powerful, and less colored?
This is how it works.
The force F acting upon the membrane comes from the current I of the voice coil wire length L that moves in the magnetic gap adn the field B with the formula F= B*I*L
L and is fixed parameters defined by the construction of the magnetic drive system. So we see that the force F is directly proportional to I current. The speaker is by it´s construction CURRENT DRIVEN and NOT voltage driven. The transconductance amplifier transforms the voltage signal (nice music hopefully) to a current! That we by definition wanted right? This works well in an active loudspeaker system where no other passive crossovers is involved. Thats why this construction isn´t very common, and this is not for every one since you have to do some adjustments to get it work properly (oscillation). The side effect is the you can reduce the distortion of the woofer from 20% to 2%, that means with factor 10 . That is coloration we are talking about, that is smearing out details and ADDING harmonics that is not present in the music signal from the beginning. So where does this distortion comes from and how is it reduced by a strange amplifier topology that none uses?
When the signal current induces a magnetic field around the voice coil, eddy currents in the pole pieces is generated and creates voice coil position impedance variations. Also the voice coil current heats up the copper which in turn increases the resistance and adds compression. And the voice coil itself has 6 ohms resistance when its cold, after some minutes it reaches 6,2 ohms.... A current amplifier will correct this!
It will continue to move the speaker even if the resistance is changing to 10ohm!
If you have a cable with 0.0001 ohm or 3 ohms it will play exactly the same with current drive! The other benefits I can mention another day.
Damping factor is a bit of a construct.
It is easier for the average punter to accept that a DF of 80 is good rather than understand that an output impedance of 0.1 ohm is good - a big number has got to be better, right!
An amplifier with low output impedance controls the woofer and produces tight sounding bass, free from overhang.
Listening tests reveal that a DF of around 20 is the break point for audibility with most loudspeakers. Transistor amplifiers exceed this figure by a substantial margin.
Any resistance that lies in the signal path between amplifier and woofer will limit the influence of a high damping factor. For example, a resistance of a few tenths of an ohm will mean that a DF of around 30 may be the best that an 8 ohm woofer will see, or just 15 with a 4 ohm woofer.
This makes high damping factors academic.
Finally, since the resistance of 7m of your suggested speaker cable is only 0.0658 ohm, I repeat that its effect on the amplifier's bass control will be inaudible.
So. I have never heard of these different types of amplifier and I assume that they are not readily available to purchase.
I expect this is due to the nature of the amplifier and how dangerous it is for many components.
I am quite a technical person but I do not understand this amplifier technology and can’t without a lot of reading. But I have a few questions.
Do these amplifiers not have wattage ratings? If a normal amp is rated at 1000w per channel, what would it take to be the equivalent power in a current driven amp?
I expect with one of these amps, they will considerable out perform normal amps so long as the speakers and setup supports being powered by the amp without destroying them.
From reading above the requirements would be, no passive crossovers..
So I take it digital crossovers would need to be used?.
Sorry for my lack of understanding. I am quite happy with what I have learned regarding dampening factor and my system. Treating this thread in an education manner now
I expect this is due to the nature of the amplifier and how dangerous it is for many components.
I am quite a technical person but I do not understand this amplifier technology and can’t without a lot of reading. But I have a few questions.
Do these amplifiers not have wattage ratings? If a normal amp is rated at 1000w per channel, what would it take to be the equivalent power in a current driven amp?
I expect with one of these amps, they will considerable out perform normal amps so long as the speakers and setup supports being powered by the amp without destroying them.
From reading above the requirements would be, no passive crossovers..
So I take it digital crossovers would need to be used?.
Sorry for my lack of understanding. I am quite happy with what I have learned regarding dampening factor and my system. Treating this thread in an education manner now
esl 63, you have asked some questions there about distortion, but it is not audible distortion from the speaker, to understand where Joe has gone wrong I suggest you look at his posts in the Blowtorch thread and the numerous attempts made to show where he is mistaken in his analysis.
All this chatter over damping factors, and "the higher the better"....
Consider this.. McIntosh, a long-time, highly-regarded audio manufacturer, with products from the 1970's still being praised and sold for enormous prices today, has "low" damping in their much-wanted amplifiers.
Examples:
The MC2300 , a solid state monster amp with 300+ watts/channel = damping factor 14
The MC2100, solid state, 100 watts/channel - damping factor 14
YET.... these amps are in demand, fought over by audiophiles.
Tell me.... why is that?
Consider this.. McIntosh, a long-time, highly-regarded audio manufacturer, with products from the 1970's still being praised and sold for enormous prices today, has "low" damping in their much-wanted amplifiers.
Examples:
The MC2300 , a solid state monster amp with 300+ watts/channel = damping factor 14
The MC2100, solid state, 100 watts/channel - damping factor 14
YET.... these amps are in demand, fought over by audiophiles.
Tell me.... why is that?
A lot of marketing and later a lot of nostalgic glamour from fanboys.
Apart from that "damping factor" is irrelevant. Post #53 gives most relevant points.
Apart from that "damping factor" is irrelevant. Post #53 gives most relevant points.
I said that the average punter thinks that a big DF number must be better, but that high damping factors are merely academic.
Damping factor should not be considered in isolation - it is the synergistic combination of amplifier and loudspeaker that determines the resulting sound.
Loudspeakers with high self-damping characteristics are likely to sound good with the McIntosh low damping factor monster - others may not.
Theses amp are designed for use with speakers that are no more than 2 meters away from the amplifier connected via audiophile quality speaker wire and connectors that probably have a low resistance. To a speaker that’s probably 8ohms.
Just because the dampening factor starts at the number 14 doesn’t mean it ends at that number once everything else is considered.
But would you really connect that amp up to a 4ohm 15” sub 7 meters away? I don’t think so.
I think a 15 inch monster sub would need an amp with more control over its cone than some floor standing speakers in smallish cabinets.
- Status
- Not open for further replies.