capslock said:
For what it is worth, there is an ignore function...
Goto the profile for the person whose posts you wish not to see, then at the bottom click the link 'Add xxxxx to Your Ignore List'
Thank You so much for the ignore info. My blood pressure might return to normal. I don't know who you might be referring to 🙄 but by his own admission he has been banned from other sites. When will he learn that an opinion isn't a very high level contribution to a thread if it doesn't add a useful concept or technical back-up!
Groman ... Maybe you should listen a bit to what we say...
No one in this forum would have any bad negative feellings about you if you listen a bit to what we say...
Serious!! You will get a lot of friends here... I think that is what makes people happy...
Sonny
No one in this forum would have any bad negative feellings about you if you listen a bit to what we say...
Serious!! You will get a lot of friends here... I think that is what makes people happy...
Sonny
Hi Groman,
we have had some overley manic people here and they get told, and politely, so don't take it personally.
Perhaps you should work on your english a little (some of your translations don't make a whole lot of sense), and post stuff that is friendly and relevant to the discussion concerned, such as interesting observations, knowledge, experience or advice - that is how you get respect round here.
Variac - chill.
Regards, Eric.
we have had some overley manic people here and they get told, and politely, so don't take it personally.
Perhaps you should work on your english a little (some of your translations don't make a whole lot of sense), and post stuff that is friendly and relevant to the discussion concerned, such as interesting observations, knowledge, experience or advice - that is how you get respect round here.
Variac - chill.
Regards, Eric.
info etc
..and, I may add, be honest. You (gromanswe) posted on another
thread that you had a *local* volume control working, but you ignored requests for specific details. Unless you come up with those, I can only conclude that gromanswe lied. That is unforgiveable on a board like this. People may spend money or go in a specific direction based on your info. If you talk nonsense or outright lies, that resets your trustworthiness to zero. I myself will ignore gromanswe's posts because so far I don't know if he is joking, lies or has something worthwhile to offer.
Jan Didden
..and, I may add, be honest. You (gromanswe) posted on another
thread that you had a *local* volume control working, but you ignored requests for specific details. Unless you come up with those, I can only conclude that gromanswe lied. That is unforgiveable on a board like this. People may spend money or go in a specific direction based on your info. If you talk nonsense or outright lies, that resets your trustworthiness to zero. I myself will ignore gromanswe's posts because so far I don't know if he is joking, lies or has something worthwhile to offer.
Jan Didden
Maybe the Son of Dork guys should consider this
The irony is that I thought the local volume control was a really good idea and I had never heard of it or thought of it before.
I told him this. Maybe he just got a little carried away.
Clearly Gromanswe has some things to contribute to the forums,
but as I was putting him on my ignore list I noted his posts averaged 13.5 per DAY. I don't think anyone here could come up with over 13 useful posts a day. Hey Gromanswe, just cut down the posts a bit to the ones that you can really contribute to and keep 'em short, and you will be very appreciated here😉
The irony is that I thought the local volume control was a really good idea and I had never heard of it or thought of it before.
I told him this. Maybe he just got a little carried away.
Clearly Gromanswe has some things to contribute to the forums,
but as I was putting him on my ignore list I noted his posts averaged 13.5 per DAY. I don't think anyone here could come up with over 13 useful posts a day. Hey Gromanswe, just cut down the posts a bit to the ones that you can really contribute to and keep 'em short, and you will be very appreciated here😉
that is not my way
so I will not do it
as it would'nt be me
and groman is who I want to be!
what do you want....
so I will not do it
as it would'nt be me
and groman is who I want to be!
what do you want....
To me dampening factor has very little or no effect. Like Douglas Self said, "the dampening factor will contribute to 0.67% of the sound." If anybody did an experiment on dampening factor verses frequency. They will see an inconsistant dampening factor spec.
Look up http://www.trueaudio.com/post_013.htm
Look up http://www.trueaudio.com/post_013.htm
Trying to hear an exotic amplifier before buying is like seeing a pig fly.
Groman if you have nothing else better to say in this Forum you should go somewhere else. If you just want to make a lot of posts, make your own thread and talk to yourself. Nobody is very interested in what you say.
top of the line speaker has >0.43 series resistance in crossover
Well, I am humbled! I have measured the components in the bass crossover of my highly respected (were second highest class in the German Stereoplay magazine in their time) T+A T160E speakers. Turns out the woofers (2x5R6 DC resistance, connected in parallel) are driven trough two series connected inductors with a total series resistance of 0.43R. There is a dubious optional bass boost circuit which puts 800 uF in series. I suspect the two paralleled capacitors to add another 0.2-0.5 R.
So on this speaker, which is probably better than 95% of the speakers around, it really won't matter whether amp and cable add a few mR...
If I knew what influence the speaker reactance has on the total frequency response, I'd probably do away with the passive filter and go active for the bass section...
Eric
Well, I am humbled! I have measured the components in the bass crossover of my highly respected (were second highest class in the German Stereoplay magazine in their time) T+A T160E speakers. Turns out the woofers (2x5R6 DC resistance, connected in parallel) are driven trough two series connected inductors with a total series resistance of 0.43R. There is a dubious optional bass boost circuit which puts 800 uF in series. I suspect the two paralleled capacitors to add another 0.2-0.5 R.
So on this speaker, which is probably better than 95% of the speakers around, it really won't matter whether amp and cable add a few mR...
If I knew what influence the speaker reactance has on the total frequency response, I'd probably do away with the passive filter and go active for the bass section...
Eric
Hi Eric
Below you see, in a simplified form what an amplifier basically
"sees", when a bare driver or a driver in a closed box (to keep things simple) is connected to it.
The mechanical resonance is elecromagnetically transformed into an electrical resonant circuit prensent at the driver's terminals. The damping of this resonance is mainly achieved by the diver's "motor" connected to the amp via the winding resistance (Re) which is the dominant part when it comes to adding together all series resistances.
A good designer is taking the series impedances of x-over components into account when determining the tuning of the box (any positive series resistance increases Qes).
If you now go active and drive your woofer directly from a power amp this will have some influence on the tunig/damping. If better or worse or to your like/dislike -- you will have to try out and judge by yourself, but I am positive about that, beeing a fan of active solutions.
The trick with the series capacitance is one of the favourite tricks of Mr. Timmermanns, the editor of the German magazine "Hobby HiFi". It is adding another order into the bass system's transfer function and is trading off a little more bass at the lower end - against a steeper rolloff.
In an active system this behaviour could be achieved electronically without the need of large and expensive capacitors.
Regards
Charles
P.S. The values shown would be for a typical driver in a box with a Qtc of 0.6 approx and an fsb of 50 Hz approx.
Below you see, in a simplified form what an amplifier basically
"sees", when a bare driver or a driver in a closed box (to keep things simple) is connected to it.
The mechanical resonance is elecromagnetically transformed into an electrical resonant circuit prensent at the driver's terminals. The damping of this resonance is mainly achieved by the diver's "motor" connected to the amp via the winding resistance (Re) which is the dominant part when it comes to adding together all series resistances.
A good designer is taking the series impedances of x-over components into account when determining the tuning of the box (any positive series resistance increases Qes).
If you now go active and drive your woofer directly from a power amp this will have some influence on the tunig/damping. If better or worse or to your like/dislike -- you will have to try out and judge by yourself, but I am positive about that, beeing a fan of active solutions.
The trick with the series capacitance is one of the favourite tricks of Mr. Timmermanns, the editor of the German magazine "Hobby HiFi". It is adding another order into the bass system's transfer function and is trading off a little more bass at the lower end - against a steeper rolloff.
In an active system this behaviour could be achieved electronically without the need of large and expensive capacitors.
Regards
Charles
P.S. The values shown would be for a typical driver in a box with a Qtc of 0.6 approx and an fsb of 50 Hz approx.
Taking the speaker cable out of the equation ?
I just had a nice cup of coffey with my girlfriend, and while we were talking about something else I had an idear.
How about taking the NFB from the fpeaker terminals (The live one) insted of keaping it inside the box.
Has it wver been done ? and could it be stable ???
Has anyone tried this ?
\Jens
I just had a nice cup of coffey with my girlfriend, and while we were talking about something else I had an idear.
How about taking the NFB from the fpeaker terminals (The live one) insted of keaping it inside the box.
Has it wver been done ? and could it be stable ???
Has anyone tried this ?
\Jens
Hi Jens
The ones that just crossed my mind are the Spectron amplifiers and the Dutch company Stage Accompany (SA). They supply speaker cables with integrated feedback lines. That is they don't go into the Speaker (at least to my knowledge - maybe SA does this for actively driven P.A. Speakers) but take feedback at the end of the cable.
This is indeed a solution to eliminate the cable resistance's detrimental effect on damping factor.
But you can do it only before the crossover or else use active solutions - AND as you seem already beeing alert of: it may deteriorate stability.
SA once stated a damping factor in the range of several thousand using this technique (or even 10 000 ?!).
But as already mentioned before: There is little sonic difference between a DF of several hundred and several thousand (if the ONLY differenc is DF).
Another solution is the use of amplifiers with negative output resistance which would even allow lowering of the Qtc, but such things have to be done with great care or "things might get interesting"*.
Or you can do the contrary and use current-drive instead of voltage drive which eliminates the effect of any series resistance (even heat related efficiency decrease !) and voice-coil inductance completely, but then special action has to be taken around the driver's fundamental resonance.
Regards
Charles
* the originator of this ingenious phrase is Nelson Pass although not in the context of damping factor.
The ones that just crossed my mind are the Spectron amplifiers and the Dutch company Stage Accompany (SA). They supply speaker cables with integrated feedback lines. That is they don't go into the Speaker (at least to my knowledge - maybe SA does this for actively driven P.A. Speakers) but take feedback at the end of the cable.
This is indeed a solution to eliminate the cable resistance's detrimental effect on damping factor.
But you can do it only before the crossover or else use active solutions - AND as you seem already beeing alert of: it may deteriorate stability.
SA once stated a damping factor in the range of several thousand using this technique (or even 10 000 ?!).
But as already mentioned before: There is little sonic difference between a DF of several hundred and several thousand (if the ONLY differenc is DF).
Another solution is the use of amplifiers with negative output resistance which would even allow lowering of the Qtc, but such things have to be done with great care or "things might get interesting"*.
Or you can do the contrary and use current-drive instead of voltage drive which eliminates the effect of any series resistance (even heat related efficiency decrease !) and voice-coil inductance completely, but then special action has to be taken around the driver's fundamental resonance.
Regards
Charles
* the originator of this ingenious phrase is Nelson Pass although not in the context of damping factor.
Active VS Passive X-over
Since the passive crossover for a LP - filter often includes an inductor, does damping change throu the freq span, or is i just a definition that includes the nominal impeedence of the speaker ?
If the same driver is driven with an active system, does the damping factor become the same ? I would prefer active cross overs anyday (It's what I was brought up with when i did my apprenticeship at B&O) Since active filters give one the option of "helping" a driver when it needs it.
Is damping generelly better in active systems, or is it just because of better filtering that they sound more precise ?
\Jens
Since the passive crossover for a LP - filter often includes an inductor, does damping change throu the freq span, or is i just a definition that includes the nominal impeedence of the speaker ?
If the same driver is driven with an active system, does the damping factor become the same ? I would prefer active cross overs anyday (It's what I was brought up with when i did my apprenticeship at B&O) Since active filters give one the option of "helping" a driver when it needs it.
Is damping generelly better in active systems, or is it just because of better filtering that they sound more precise ?
\Jens
Ringing ?
Questions/Pondering.
Assume that a typical bass driver has a DC resistance of say 6 ohms.
In the overshoot condition (after application of a pulse) such a driver acts as a generator.
When the driver is in the generator condition (overshoot) it has an output impedence of, say 6 ohms.
Radio and transmission line theory would indicate that this generator needs to be coupled with a line of same characteristic impedence, and the line loaded with the same characteristic impedence so as to eliminate signal reflections.
So is back loading (damping) a driver with an amplifier with near zero output impedence actually the wrong approach ?.
Should the damping factor be 1 ?.
There have been observations that low damping factor amplifiers can sound more pleasing, and that high DF amplifiers can be displeasing.
I use 25 pair telephone cable that gives a characteristic impedence of around 8 ohms I think.
I find this cable to give a typically more pleasing result on most systems.
Are we listening to high frequency ringing conditions causing intermod distortion in high DF (high loop NFB) amplifiers ?.
Eric.
Questions/Pondering.
Assume that a typical bass driver has a DC resistance of say 6 ohms.
In the overshoot condition (after application of a pulse) such a driver acts as a generator.
When the driver is in the generator condition (overshoot) it has an output impedence of, say 6 ohms.
Radio and transmission line theory would indicate that this generator needs to be coupled with a line of same characteristic impedence, and the line loaded with the same characteristic impedence so as to eliminate signal reflections.
So is back loading (damping) a driver with an amplifier with near zero output impedence actually the wrong approach ?.
Should the damping factor be 1 ?.
There have been observations that low damping factor amplifiers can sound more pleasing, and that high DF amplifiers can be displeasing.
I use 25 pair telephone cable that gives a characteristic impedence of around 8 ohms I think.
I find this cable to give a typically more pleasing result on most systems.
Are we listening to high frequency ringing conditions causing intermod distortion in high DF (high loop NFB) amplifiers ?.
Eric.
Hi Jens
The control of the amp over the driver does indeed change over frequency influenced by any component between speaker and amp.
The direct connection of amp and speaker is actually one of the reasons that make them sond more clean. The German magazine
"Klang & Ton" (a mag about speaker building) went active with one of their flagship designs and they measured a distinctive decrease in DRIVER related THD !
But this does not per se mean that every amp would like driving every bare driver.
Another reason is that you can theoretically correct for whatever warped frequency response of your driver you like to (although rationality sets limits here).
You don't even have to live with the TS-parameters your driver is delivered with, i.e. you can artificially alter them if you like !!!
You can use analog computing techniques to achieve flat frequency response AND perfect transient response (i.e. subtractive crossovers).
You can use MFB (motional **************) techniques to have even more control over a cone's motion. Although I am not a fan of this.
Regards
Charles
I am wondering when the automatic parser will be going to scan for "OP-AMP", "ceramic capacitor", "electrolytic" and Bose as well !! 😉 😀
The control of the amp over the driver does indeed change over frequency influenced by any component between speaker and amp.
The direct connection of amp and speaker is actually one of the reasons that make them sond more clean. The German magazine
"Klang & Ton" (a mag about speaker building) went active with one of their flagship designs and they measured a distinctive decrease in DRIVER related THD !
But this does not per se mean that every amp would like driving every bare driver.
Another reason is that you can theoretically correct for whatever warped frequency response of your driver you like to (although rationality sets limits here).
You don't even have to live with the TS-parameters your driver is delivered with, i.e. you can artificially alter them if you like !!!
You can use analog computing techniques to achieve flat frequency response AND perfect transient response (i.e. subtractive crossovers).
You can use MFB (motional **************) techniques to have even more control over a cone's motion. Although I am not a fan of this.
Regards
Charles
I am wondering when the automatic parser will be going to scan for "OP-AMP", "ceramic capacitor", "electrolytic" and Bose as well !! 😉 😀