You need a soundstage knob, knock that sibilance right out of the park .....
https://m.youtube.com/watch?v=qjkGPvrQP5s
Yes yes. all true. Guess, I'll have to do it and show it. Leaving for LA in the morning. Leaving for Asia in 2 weeks. .... to be continued.
THx-RNmarsh
75% marketing, 25% product value, right?
Sure enough, most people are just plain silly.
Ciao,
I'd say more like 90-10.
I was implying that since they survive against the trend, they must do 'something' right. I don't know the brand well enough to know in detail what it is they do 'right'.
But I would venture that brand positioning, advertising and image building plays a large, if not the largest, part in doing 'it' right. Of course after the customer has been convinced to buy the thing, it must sound good enough for him to be happy about his purchase. This will provide positive feedback to reinforce the brand image and lead to more sales. So it's an interlocked set of issues that have to be considered to be successful, and sound quality is one, but I don't think it is the most important one.
Everybody hates Bose for sound quality yet Amar build a billion-dollar company on this supposedly bad sound, so he was also doing 'something' right!
Jan
Jan,
On Amar Bose - I don't know how much he knows about audio, but I am certain he is a marketing guru. He, or somebody from his company, have a very keen ear and eye for market trends, and he will adapt to anything, including waterptoof toilet systems.
On Naim - I haven't heard anything by them for quite a while, but what I have heard always seemed a bit odd to me. Not bad, but with a distinct specific blend. And it was always there, big or small, cheap or expensive, if theirs, then same general blend. Obviously, some people love it, and that's all right, but that is definitely not my cup of coffee. I prefer audio which does not have any particular blend to it.
But do take a look at the German e-bay, for example, and you will notice that their gear doesn't fetch half as much there as it doesn in the UK.
On Amar Bose - I don't know how much he knows about audio, but I am certain he is a marketing guru. He, or somebody from his company, have a very keen ear and eye for market trends, and he will adapt to anything, including waterptoof toilet systems.
On Naim - I haven't heard anything by them for quite a while, but what I have heard always seemed a bit odd to me. Not bad, but with a distinct specific blend. And it was always there, big or small, cheap or expensive, if theirs, then same general blend. Obviously, some people love it, and that's all right, but that is definitely not my cup of coffee. I prefer audio which does not have any particular blend to it.
But do take a look at the German e-bay, for example, and you will notice that their gear doesn't fetch half as much there as it doesn in the UK.
You are completely out of your water here.
On the one hand, you argue that there are audible differences, even between amplifiers of the same make and model.
At the same time, you apparently have never heard a loudspeaker going out of alignment at elevated SPL.
The voice coil of a driver will increase in resistance by 50% between room temperature and 150 degrees C. In a 1st order alignment, this will cause the -6dB xover point of the low pass to increase by 50%, and the -6dB xover point of the high pass to decrease by about 33%. For example, in a nominally 2KHz xover, the low pass will increase to 3KHz and the high pass will decrease to 1.3KHz.
Almost all energy fed into a loudspeaker is turned into heat. So believe you me, 150 degrees in a VC is not unheard of if you play loud.
As to the heat increase in xover caps: first of all, it has nothing to do with their voltage rating, but with their internal loss mechanisms (DA, ESR). Let's limit ourselves to ESR. We are talking mOhms here. So, first of all, the heating up is not that much. Caps in xovers may get warm, but most of them would certainly self destruct at the temperatures habitually reached in voice coils. But even if they would go that high, the increase in R would be limited to a percentage of mOhms. Nothing to worry about.
One thing that helped slightly was to finish damping the input shunt cap, since it was resonating with the source and picking up radio at 6MHz.
Any kind of resonance seems to cause sibilance which can be improved by damping. However this is pretty much the most resonance-free circuit I've ever had on my bench. It's quite surprising really. It does however have some overshoot which I will be looking at tomorrow.
The signal was digitally generated and there is no problem to send it to an amplifier and analyze both by scope and FFT analysis. 'Normal' amplifer will have no problems.
Attachments
Have you measured or is this Wikipedia....
Again you say loud , i said domestic , have you ever measured how much power is required to raise VC TEMP to 150, i have measured while testing and have never seen such temps unless in sound reinforcement where there is no xover. In domestic use its pretty rare to be using more than 10-15 watts RMS EVEN at elevàted volume and yes , I'm aware of this strawman argument from those pushing the virtues of Horns ...
I have seen caps fail in xovers big time and i never said it had anything to do with ESR , i mentioned this could be more of a concern than heating VC's in domestic use, you should measure...
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I have seen caps fail in xovers big time and i never said it had anything to do with ESR , i mentioned this could be more of a concern than heating VC's in domestic use, you should measure...
They usually fail due to over voltage.... most home systems use caps in cross over which are rated for 100vdc.
THx-RNMarsh
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using the specific waveform I put up was in fact used and a white paper generated by Japanese consumer electronics company a long time ago. It did show nonlinearities behaviour and signature of topologies. Cant find the paper at this time. Maybe some old timer here will recognise it. But would be worth a rerun with todays amps... and for Tube and old favorites which are still being made here at DIY Land as well as new designs.
THx-RNMarsh
I suppose in a commercial xover where you are only using a single cap to attain your value and the voltage rating is rather low you could see failed caps. But when I have done crossovers of close tolerance I have used multiple caps of 100v rating in parallel. I would like to see what it takes to have a failure with 3 or 4 100v pp caps in parallel? I will say that in some older cheap xovers it wasn't so uncommon to see 25v or 50v electrolytic caps, there I can imagine you could have a failure.
If somebody is using a typical bookshelf speaker with a 84 to 86db efficiency you can imagine the peak drive voltage at high output levels and especially fast peak transients. This is where you will get those high voicecoil temp. Dome tweeters are hurt this way all the time especially when you happen to clip the amplifier if used with a single channel driving both the bass/mid and dome at the same time with a passive crossover. I would say clipping amplifier behavior at high levels will be your most common failure mode in a domestic speaker system.
Now I'll throw in another thing to think about. Voicecoil length vs gap length. Many speakers will use an overhung voicecoil in the mistaken belief that this is a linear drive method, it truly never is, which exposes large areas of the voicecoil to nothing but free air. Where is the heat generated in that coil supposed to dissipate? Air has a poor transfer rate in this regard compared to an equal hung or underhung voicecoil and the transfer of that heat into the steel of a typical top plate and pole piece. Look at the resistive impedance rise due to that voicecoil hanging in space vs one contained in a gap.
If somebody is using a typical bookshelf speaker with a 84 to 86db efficiency you can imagine the peak drive voltage at high output levels and especially fast peak transients. This is where you will get those high voicecoil temp. Dome tweeters are hurt this way all the time especially when you happen to clip the amplifier if used with a single channel driving both the bass/mid and dome at the same time with a passive crossover. I would say clipping amplifier behavior at high levels will be your most common failure mode in a domestic speaker system.
Now I'll throw in another thing to think about. Voicecoil length vs gap length. Many speakers will use an overhung voicecoil in the mistaken belief that this is a linear drive method, it truly never is, which exposes large areas of the voicecoil to nothing but free air. Where is the heat generated in that coil supposed to dissipate? Air has a poor transfer rate in this regard compared to an equal hung or underhung voicecoil and the transfer of that heat into the steel of a typical top plate and pole piece. Look at the resistive impedance rise due to that voicecoil hanging in space vs one contained in a gap.
When it comes to caps, I trust Richard Marsh first. Why? Because he still thinks they are important, and he has done considerable research, and actually received a patent for one of his cap designs.
Now getting to 'quibbling', it does not NECESSARILY follow that DA is directly proportional to linearity, BUT there is usually a strong correspondence between distortion and DA. One exception MIGHT BE the DA in an NPO ceramic cap. Is it virtually unmeasurable, or is it relatively high? (like Mylar, for example) I don't know for sure.
However, the MODEL used by Dow, and copied by Pease is a LINEAR model, and has no non-linear parts in it, so it cannot be used to correlate the linear and non-linear distortion in caps. It must be remembered the the original DA model was for a polystyrene cap, that is well known to be very linear. Of course, the model can be used for Tantalum or Aluminum caps as well as all others, but it will not predict the non-linearity that is present in the cap as well.
Now getting to 'quibbling', it does not NECESSARILY follow that DA is directly proportional to linearity, BUT there is usually a strong correspondence between distortion and DA. One exception MIGHT BE the DA in an NPO ceramic cap. Is it virtually unmeasurable, or is it relatively high? (like Mylar, for example) I don't know for sure.
However, the MODEL used by Dow, and copied by Pease is a LINEAR model, and has no non-linear parts in it, so it cannot be used to correlate the linear and non-linear distortion in caps. It must be remembered the the original DA model was for a polystyrene cap, that is well known to be very linear. Of course, the model can be used for Tantalum or Aluminum caps as well as all others, but it will not predict the non-linearity that is present in the cap as well.
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