If the amp is truely a voltage source, and it isn't if its a tube amp, then the voltage is independent of the load and a parallel resistor won't make a bit of difference. Tube amps have a lot of output impedance and there will be a big difference.
B&Cs 8 ohn compression drivers are all 6.3 ohms DC and the 16 ohm ones are only about ten ohms.
B&Cs 8 ohn compression drivers are all 6.3 ohms DC and the 16 ohm ones are only about ten ohms.
passive=not as good as active
YES to the first part save for the effects of the passive crossover itself soft of... Adding a resistor in parallel can make a passive high level crossover behave very differently than some other method. A series resistor simply smears the sound which can hide many sins. Buy a cheap full range driver (<$30) and listen to it connected directly to the amplifier. Then add your series resistor and listen. You will find degradation of the sound with anything put between the amp and the cheap speaker. NOW imagine what your REAL speaker does??
Anything between the amp and the speaker is in the way of the sound. This is why every driver should have its' own private amplifier. You have it very right that passive high level anything is a big problem.
YES to the first part save for the effects of the passive crossover itself soft of... Adding a resistor in parallel can make a passive high level crossover behave very differently than some other method. A series resistor simply smears the sound which can hide many sins. Buy a cheap full range driver (<$30) and listen to it connected directly to the amplifier. Then add your series resistor and listen. You will find degradation of the sound with anything put between the amp and the cheap speaker. NOW imagine what your REAL speaker does??
Anything between the amp and the speaker is in the way of the sound. This is why every driver should have its' own private amplifier. You have it very right that passive high level anything is a big problem.
Wow, this discussion sees to have gone off on some strange esoteric tangent.
What about simple practical concerns?
For most folks the only difference between an 8 and 16 ohm driver is going to be the crossover. Period. The subtle differences discussed in this thread are likely to be completely swamped by room acoustics, seating position, good or bad crossovers, etc.
You might try to choose a compression driver that is nominally the same impedance as your woofer, but that's all. Either will work fine.
What about simple practical concerns?
For most folks the only difference between an 8 and 16 ohm driver is going to be the crossover. Period. The subtle differences discussed in this thread are likely to be completely swamped by room acoustics, seating position, good or bad crossovers, etc.
You might try to choose a compression driver that is nominally the same impedance as your woofer, but that's all. Either will work fine.
Stupid question. Resistor in parallel to driver --> more current drawn from amp but part of it will go to resistor and turn to heat. Where is the sense?
And what about lighter VC of 16 ohm driver, will it heat up earlier which gains resistance even more?
And what about lighter VC of 16 ohm driver, will it heat up earlier which gains resistance even more?
There is no sense if the device is directly connected to the amp. But if it follows a passive HP then the flattening of the load impedance with the parallel resistor is a big advantage. The impedance of a Cpompression driver can be quite complex and this can cause all kinds of problems to a passive crossover. SInce the HF virtually always need to be padded down, this loss of power to the driver helps to pad as well as to smooth the load.
Yeah, I noticed that Z smoothing thing.
Semi offtopic, what do you think should I try to connect 8 ohms parallel to my tweeter (and change cap to tweeter for the same XO point)? I have this kind of speakers. Only cap in tweeter, nothing else XO.
What are those resistor "mods" negative sides?
Semi offtopic, what do you think should I try to connect 8 ohms parallel to my tweeter (and change cap to tweeter for the same XO point)? I have this kind of speakers. Only cap in tweeter, nothing else XO.
What are those resistor "mods" negative sides?
Actually it is not off subject so much because the better sound comes from the higher Z driver. In the old days we could buy 32 ohm drivers and they sounded so sweet compared to there 8 ohm counterpart only the deaf could not hear the difference. We have gone as far a having high Z compression drivers made but these days with massive production this is not an option.
I thought the goal was to give a chance to get to the better sound and not just something that makes noise.
I wouldnt make 16ohm a priority
It would limit your options
And your best option may not be available in other than 8ohm
But if its in general, I would expect some drivers might sound better in 16ohm, while other wouldnt
I would look at each driver seperately, and not generalise
It would limit your options
And your best option may not be available in other than 8ohm
But if its in general, I would expect some drivers might sound better in 16ohm, while other wouldnt
I would look at each driver seperately, and not generalise
You are correct of course.
Having tested a lot of the 4, ohm, 8 ohm, and 16 ohm version of the same driver (or woofer or midrange) it has only been every time the high Z driver was better in every way other than the higher drive voltage needed.
Best sounding driver for domestic use would have powerhandling around 10watt or so, lowish 100db SPL, and based on thin and short wire in underhung design, that would be sweet
And to build one based on a replacement diaphragm should be possible
Coating might be another option
And to build one based on a replacement diaphragm should be possible
Coating might be another option
The excursion in a compression driver is so low that an underhung VC would just be a waste of flux. And I'd rather have nice beefy wire that doesn't get as hot and compress the output.
I doubt very much that 10watt will cause any compression
Besides, Im not interested in 120db SPL
But others may be, I know that
We just have different goals
Flux is not a problem either, it will be plenty
With underhung you can make the voicecoil shorter
You wont loose much flux, but only have lower SPL
And underhung will deal with part of the possible heat induced compression
With a short voicecoil underhung design is the perfect choise
I only see advantages
This is also the foundation for many new exotic hifi tweeters
Very short low impedance underhung voicecoil is not just for fun
Besides, Im not interested in 120db SPL
But others may be, I know that
We just have different goals
Flux is not a problem either, it will be plenty
With underhung you can make the voicecoil shorter
You wont loose much flux, but only have lower SPL
And underhung will deal with part of the possible heat induced compression
With a short voicecoil underhung design is the perfect choise
I only see advantages
This is also the foundation for many new exotic hifi tweeters
Very short low impedance underhung voicecoil is not just for fun
Well its not for better sound either.
No, I think that we have the same goals, we just believe different things. I believe what I believe because I have tested it in accurate subjective tests. I'm guessing you believe what you believe because you heard it for yourself.
This is fine as an opinion. Your experience is certainly welcome.
But I have yet to see or hear anything that leads me to believe that 16 ohm drivers sound much better than 8 ohm versions of the same driver. I have not ever heard it, and this is the first time I've ever seen anyone mention it.
If you have some documentation of this, it would be great to see. Because given the choice, we want the better driver! If it is as simple as choosing 16 ohms over 8, then it's a no-brainer.
The second statement is a special case because the impedance ratio is 4, meaning a bifilar coil can be used and connected in series or parallel.
But when making drivers with an impedance ratio of two, say 4/8 ohm versions or 8/16 ohm versions, the parameters will be slightly different even if you tweak other stuff. This is because the voice coil wire must be different, and ends up with different length or more wire in the gap and so on. Even if you just lengthened the 8 ohm coil twice as long, there would be more moving mass and it would pick up more BL product. If you tried to reduce the moving mass elsewhere, the driver would have other different characteristics.
The final impedance will depend a lot on the horn and horn termination, so the actual impedance should be measured. It may be really messy, which is why active crossovers can be much better for horns, because a passive crossover won't work ideally even with Zobel networks.
Anyway, unless using ultra sensitive woofers, the 16 ohm driver is probably more than sensitive enough. (Simplistic thinking would say "hey, 16 ohms is double 8 ohms, so it will have 3 dB less output for the same voltage"-but in reality, due to smaller gauge of wire in the gap cutting more flux-turns, the difference may be less).
But when making drivers with an impedance ratio of two, say 4/8 ohm versions or 8/16 ohm versions, the parameters will be slightly different even if you tweak other stuff. This is because the voice coil wire must be different, and ends up with different length or more wire in the gap and so on. Even if you just lengthened the 8 ohm coil twice as long, there would be more moving mass and it would pick up more BL product. If you tried to reduce the moving mass elsewhere, the driver would have other different characteristics.
The final impedance will depend a lot on the horn and horn termination, so the actual impedance should be measured. It may be really messy, which is why active crossovers can be much better for horns, because a passive crossover won't work ideally even with Zobel networks.
Anyway, unless using ultra sensitive woofers, the 16 ohm driver is probably more than sensitive enough. (Simplistic thinking would say "hey, 16 ohms is double 8 ohms, so it will have 3 dB less output for the same voltage"-but in reality, due to smaller gauge of wire in the gap cutting more flux-turns, the difference may be less).
Warning- A big soapbox below-
Now I am going to soapbox....
Have you panomaniac (and this goes for some of you other guys out there also especially the people who model and never go to the laboratory) ever measure one driver or circuit in the laboratory? Have you ever measured the harmonic and IM distortion, frequency response, power handling, phase response, resonant frequency, moving mass, or any other transducer property in the laboratory? What I state is not an opinion though what you state seems very likely to be one. I have measured these items on over 1000 drivers of all shapes and sizes and guess what, EVERYTIME with all things being otherwise equal the 16 ohm outperformed in every important way its 8 ohm counterpart. And I do not mean just looking at some impedance graph either. I mean direct measurement of BL and moving mass and not using the very error prone methods laid out by Small. I have little use for opinion other than for aesthetic preferences. I do hold DIRECT LABORATORY MEASUREMENTS in high regard and every statement I make on DIY audio is exactly that- the result of 35 years of professional audio in the lab and in the field designing building, manufacturing, and installing every aspect of audio systems before the digital age. I have MY lab since 1980 and been in one since 1976. TEF, HP spectrum analyzer, IASYS, LMS, DSP based measurement systems of my own design, analog measurement systems of my own design, and on and on all right here at my finger tips. Do you have ready access to any test equipment beyond a DVM? And guess what I do not need to measure anymore? The transducer with all things being equal and voice coil wound for 8 ohm or 16 ohm the 16 ohm will ALWAYS be better in every important way. THAT IS A FACT and your tossing your opinion without laboratory or manufacturer data to support it does not help anyone. Oh yes, by the way I also make drivers and have a voice coil winding machine for handy prototype fabrication and lots of speaker bits and pieces in the way around here. I am please to say we have designed here some of the most copied drivers in the world.
So if someone out there is ready to take it to task with me that person better have both feet cast in concrete in LABORATORY direct measurement and not a bunch of first approximation theory (Theil) to lean on. I will chew you down to the size you are. Theory is great but THEORY IS NOT THE REAL THING. Reading about sex will never tell anyone what the experience is and theory and models are exactly that compared to laboratory direct measurements.
I try to be civil and hope this does not get me kicked off the forum as I am here to add great knowledge and experience being helpful because I am bored and extremely knowledgeable.
Now I am going to soapbox....
Have you panomaniac (and this goes for some of you other guys out there also especially the people who model and never go to the laboratory) ever measure one driver or circuit in the laboratory? Have you ever measured the harmonic and IM distortion, frequency response, power handling, phase response, resonant frequency, moving mass, or any other transducer property in the laboratory? What I state is not an opinion though what you state seems very likely to be one. I have measured these items on over 1000 drivers of all shapes and sizes and guess what, EVERYTIME with all things being otherwise equal the 16 ohm outperformed in every important way its 8 ohm counterpart. And I do not mean just looking at some impedance graph either. I mean direct measurement of BL and moving mass and not using the very error prone methods laid out by Small. I have little use for opinion other than for aesthetic preferences. I do hold DIRECT LABORATORY MEASUREMENTS in high regard and every statement I make on DIY audio is exactly that- the result of 35 years of professional audio in the lab and in the field designing building, manufacturing, and installing every aspect of audio systems before the digital age. I have MY lab since 1980 and been in one since 1976. TEF, HP spectrum analyzer, IASYS, LMS, DSP based measurement systems of my own design, analog measurement systems of my own design, and on and on all right here at my finger tips. Do you have ready access to any test equipment beyond a DVM? And guess what I do not need to measure anymore? The transducer with all things being equal and voice coil wound for 8 ohm or 16 ohm the 16 ohm will ALWAYS be better in every important way. THAT IS A FACT and your tossing your opinion without laboratory or manufacturer data to support it does not help anyone. Oh yes, by the way I also make drivers and have a voice coil winding machine for handy prototype fabrication and lots of speaker bits and pieces in the way around here. I am please to say we have designed here some of the most copied drivers in the world.
So if someone out there is ready to take it to task with me that person better have both feet cast in concrete in LABORATORY direct measurement and not a bunch of first approximation theory (Theil) to lean on. I will chew you down to the size you are. Theory is great but THEORY IS NOT THE REAL THING. Reading about sex will never tell anyone what the experience is and theory and models are exactly that compared to laboratory direct measurements.
I try to be civil and hope this does not get me kicked off the forum as I am here to add great knowledge and experience being helpful because I am bored and extremely knowledgeable.
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