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As it is, your question is a bit like “what’s better: ant eaters or paint brushes. I understand why you ask the question but you’re putting the cart before the horse. Your engineering a solution without defining the goals or challenges, except for a few things you mention (loud rock in a big room).
Rock = low frequency content played loud
Big room = needs power
You express a preference for loud.
That driver has low distortion from around 200-300hz and looks like it will not be too directional until over 3khz. Distortion rises below 200 hz. Low guitar string is 80hz or so, and low bass string 40hz.
It seems obvious you will need a low frequency driver.
The other thing your post suggests is that you are experimenting. Try build it as a two way and then add a woofer as a three way and see what happens. Try different woofer configuration such as dipole or transmission line.
Your should read the write ups on the tarkus, and Jeff bagby’s bass add on for the kairos and continuum.
The bass section of the tarkus uses an inexpensive driver that has been used by many of the best designers in diy. Jeff’s are much more expensive but he discusses the choice of woofers. The Dayton RS 10” still show up in a lot of respected designs. Jon Marsh big projects at htguide have a lot of discussion around driver selection but his xovers are advanced, complex and expensive, and he uses pricey drivers.
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Actually, I think it's more forgetting I wasn't in an anteater forum. In the audio circles I normally move it is axiomatic that all electronic components between the source and listener degrade audio pleasure, this goes double for caps, triple for inductors, and anything at speaker level is even worse. Also, multiple units wreck the soundstage.
Ergo unless one has a very good reason otherwise one uses two unit speakers with simple crossovers and lives with a lack of deep bass and a less than even frequency response.
Seen in THAT context, I was saying I have a good reason for 3 unit speakers (loud, bassy music in a large room, which is why my current main speakers are indeed three unit) and that given this system is an experiment with DSP (this house already contains four pairs of audiophile speakers and I don't need any more) most of the disadvantages of a three way speaker system disappear anyway. Fiddling in the digital domain does not involve any extra components, and one can switch the order of the crossover slopes at the touch of a button, once programmed.
So my question was that, given it's 30 years since I last looked at speaker design, have drive units moved on far enough that going three way is silly, even with DSP?
However, this is purely philosophical. I will indeed go three unit.
It's an experiment, but what I wish to experiment with is DSP. I don't wish to add any other variables, so I'll be going with a relatively conventional three sealed enclosure system using conventional well understood drive units from a single manufacturer.
Another way of doing this would be to whip the crossover out of a pair of existing three ways and replace with DSP. However I'm quite fond of all my existing speakers and am reluctant to butcher a pair!
Other than higher power handling, more durable, no, there's been no major conceptual changes since the '30s, i.e. they're still basically solenoid driven diaphragms. Can't cheat Mother Nature.
Ideally need a [5] way for 16-22 kHz, a real nightmare with passive and a trivial pursuit with DSP.
Ideally need a [5] way for 16-22 kHz, a real nightmare with passive and a trivial pursuit with DSP.
^^ No, physics is still the same as decades ago. Single biggest factor of "sound quality" is frequency response. It is silly to sacrifice frequency response for anything. Main takeaway adding ways is increase in parts, but it doesn't mean the sound quality will degrade. Cost will increase, and cost is obvious trade off to take if one is after better sound quality. Never trade-off sound quality like the frequency response which is the most basic thing anyone learns first when introduced to loudspeakers.
Yes, there might be difference between different amounts of passive parts but since using one cap instead of properly designed crossover changes things so much you cannot compare, don't know which of the changed properties affected the sound quality. Sometimes one cap is the perfect recipe but your loudspeaker acoustic design/properties will define that, what is needed from the crossover. Type of crossover doesn't matter much, only thing that matters is the acoustic output your device emits and you can measure that. Some aspects of it can be affected by the crossover but most of it is the transducers (number and size) and the cabinet (size and form). Crossover splits the sound (electronically) so that it combines back acoustically as well as possible. You need to have the complete speaker built and measured to design the crossover, it is the acoustic output you are after.
Three way is the minimum I'd say, because of the physics. If the speed of sound in your listening environment changed considerably from the standard then two way might be enough or you might need more ways depending on which gasses you now use in which temperature and pressure, given the hearing system stays unmodified 😀 but then the atmospheric music would sound weird. I'll get my coat.
Yes, there might be difference between different amounts of passive parts but since using one cap instead of properly designed crossover changes things so much you cannot compare, don't know which of the changed properties affected the sound quality. Sometimes one cap is the perfect recipe but your loudspeaker acoustic design/properties will define that, what is needed from the crossover. Type of crossover doesn't matter much, only thing that matters is the acoustic output your device emits and you can measure that. Some aspects of it can be affected by the crossover but most of it is the transducers (number and size) and the cabinet (size and form). Crossover splits the sound (electronically) so that it combines back acoustically as well as possible. You need to have the complete speaker built and measured to design the crossover, it is the acoustic output you are after.
Three way is the minimum I'd say, because of the physics. If the speed of sound in your listening environment changed considerably from the standard then two way might be enough or you might need more ways depending on which gasses you now use in which temperature and pressure, given the hearing system stays unmodified 😀 but then the atmospheric music would sound weird. I'll get my coat.
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One more, the SPL level the system is capable to reproduce with the bandwidth it is designed to is very important. It should be able to reproduce sound level that is comfortably loud. Hearing system is weird and says louder is better until the loudspeaker or the hearing says the sound quality is unpleasant. Maximum enjoyment potential is achieved when the SPL capability of the loudspeaker is beyond the limit (comfort) of your hearing. A three way speaker should be more capable in this regard than a two way, less sacrificed frequency response.
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I should have got my coat ages ago, since the question is answered, but still 🙂
Frequency response has the virtue as a parameter that it can be easily measure, but does colouration matter?
I'm listening to Melody Gardot in my office as I type this. It's furnished like a gentleman's club, small, crammed full with leather furniture, wood panelled, with a Persian carpet. Outside the door is my main system, big, sparsely furnished room, all concrete walls and ceiling with a pool table and a baby grand piano. No sofas because the bloody puppies we raise and rehome eat them. Beyond that is a conservatory, glass and concrete, marble tile floor. Each has a hifi system, and someone someone will have carefully measured the frequency response of each pair of speakers at the design stage to make them reasonably neutral
They all sound totally different, of course.
But after ten minutes in any room my brain adjusts and they sound fine (I make a possible exception for the conservatory, which makes my head hurt after an hour or so, although up to that point the sound is great, really clear and impressive, you can see how people sold bright speakers to the unwary).
The brain adjusts for colouration. But it can't adjust for the life sucked out of the music.
Of course, if you want to apply that philosophy at the extreme and make a set of speakers with one capacitor as the crossover, you will have to, as Robin Sherwood did, design a one off sophisticated and expensive bass / mid. I can't do that. So I couldn't go that far. But I'm good with the principles, and I'm still annoyed a lightening strike deprived me of those amazing speakers.
They were designed 35 years ago, hence my wondering if improved magnets, better materials and computational power to calculate finite elements had taken us far enough that an off the shelf bass/mid COULD now do the job. Or even just negate the need for a separate bass unit.
Apparently not. Can't say I'm surprised, but it was worth asking 🙂
Frequency response has the virtue as a parameter that it can be easily measure, but does colouration matter?
I'm listening to Melody Gardot in my office as I type this. It's furnished like a gentleman's club, small, crammed full with leather furniture, wood panelled, with a Persian carpet. Outside the door is my main system, big, sparsely furnished room, all concrete walls and ceiling with a pool table and a baby grand piano. No sofas because the bloody puppies we raise and rehome eat them. Beyond that is a conservatory, glass and concrete, marble tile floor. Each has a hifi system, and someone someone will have carefully measured the frequency response of each pair of speakers at the design stage to make them reasonably neutral
They all sound totally different, of course.
But after ten minutes in any room my brain adjusts and they sound fine (I make a possible exception for the conservatory, which makes my head hurt after an hour or so, although up to that point the sound is great, really clear and impressive, you can see how people sold bright speakers to the unwary).
The brain adjusts for colouration. But it can't adjust for the life sucked out of the music.
Of course, if you want to apply that philosophy at the extreme and make a set of speakers with one capacitor as the crossover, you will have to, as Robin Sherwood did, design a one off sophisticated and expensive bass / mid. I can't do that. So I couldn't go that far. But I'm good with the principles, and I'm still annoyed a lightening strike deprived me of those amazing speakers.
They were designed 35 years ago, hence my wondering if improved magnets, better materials and computational power to calculate finite elements had taken us far enough that an off the shelf bass/mid COULD now do the job. Or even just negate the need for a separate bass unit.
Apparently not. Can't say I'm surprised, but it was worth asking 🙂
Asking never hurts 🙂 As you find out even the most advanced alien technology wouldn't help too much (unless they invented physical vibrator which is big but small at the same time, or way to generate sound without physical vibrating objects) since low frequencies require loads of displacement, displacement is surface area times excursion. Big woofer it is for lows to have manageable excursion but while big woofer can play high frequencies the "self-interference" makes the output beam and off-axis sound does not resemble on axis sound anymore = coloration, the bigger the woofer the lower the frequency where beaming starts. On the other hand with a small woofer, too much excursion and both on and off-axis response get modulation. All this regardless of magnet material or wire thickness or transducer type, it is about wavelengths.
Room coloration can be controlled by the speaker designer somewhat. Best thing one can do in a speaker design is to make sure sound radiating off-axis has similar tone than the designed listening axis. Furthermore one can control the output pattern to lessen the first reflections somewhat (without killing the spaciousness completely). This however, is matter of the acoustic design of the speaker and what comes beyond that (the room) is out of control of the loudspeaker designer. Computation has progressed acoustic design possibilities of loudspeaker design and manufacturing in recent years though. Checkout the ATH thread on the multiway forum, awesome stuff. Many examples of developed computation and manufacturing techniques in the commercial sector as well. Even with the best speakers of them all, don't forget the positioning, toe in and listening position affects the experience. With good food, nice companions and beautiful sight makes speakers sound magical but if you are alone and angry nothing will sound good. Separate issues, technical side and emotional side, you should optimize both for most joyful experience, tingle all senses to the max 😀
I suggest give scientific approach a chance while you are at it. Check out Floyd Tooles book that contains info what measurable metrics have been found to sound best in blind listening tests during the years. You'll find out that smooth off axis response has been one key factor between good sounding speakers. Remember to have fun, what ever the path is you are going to take 🙂 allright, too much preaching already..
Room coloration can be controlled by the speaker designer somewhat. Best thing one can do in a speaker design is to make sure sound radiating off-axis has similar tone than the designed listening axis. Furthermore one can control the output pattern to lessen the first reflections somewhat (without killing the spaciousness completely). This however, is matter of the acoustic design of the speaker and what comes beyond that (the room) is out of control of the loudspeaker designer. Computation has progressed acoustic design possibilities of loudspeaker design and manufacturing in recent years though. Checkout the ATH thread on the multiway forum, awesome stuff. Many examples of developed computation and manufacturing techniques in the commercial sector as well. Even with the best speakers of them all, don't forget the positioning, toe in and listening position affects the experience. With good food, nice companions and beautiful sight makes speakers sound magical but if you are alone and angry nothing will sound good. Separate issues, technical side and emotional side, you should optimize both for most joyful experience, tingle all senses to the max 😀
I suggest give scientific approach a chance while you are at it. Check out Floyd Tooles book that contains info what measurable metrics have been found to sound best in blind listening tests during the years. You'll find out that smooth off axis response has been one key factor between good sounding speakers. Remember to have fun, what ever the path is you are going to take 🙂 allright, too much preaching already..
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Dipole designs attempt to reduce interaction with the room. In audiophile circles dipole is often treated as some esoteric, flawed, technology but that is based on ignorance. Go to linkwitzlabs to learn more. Directivity control is also something that didn’t used to be discussed a lot in diy and is now considered in almost every project. Anyway, this isn’t what you came here to ask, but it worth looking into. I hope you’ll let us know how it goes.
Your opinion about caps and inductors is totaly wrong. Btw.
Any active device will do far worse damage to signal than any passive element.
Best amplifiers i heared were all cap coupled, even with interstage transformer.
You keep mentioning dsp like its some kind of mirracle. Well, it is convenient, but sonically transparent it is not.
Input buffer, ADC, digital processing, DACs, outputs, all adds up.
Good luck with your project.
3-way using Avalon Style cabinet with all sealed drivers.
1" Tweeter SB26STCN-C000-4 = smooth high end + small diameter allows 50mm C-to-C after trimming the bottom portion of the tweeter faceplate
6.5" black aluminum come midrange sb17nbac34-4 = sealed enclosure
12" paper cone woofer sb34nrx75-6 = sealed enclosure
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Thanks, some practical advice! I fancy some Sonotube speakers though. Will try and get a little further with building them tomorrow.
I don't know if DSP is a miracle or not. That's why I'm doing this. As far as I can see processing in the digital domain shouldn't do any harm.
There will be no ADC. If there were an ADC I'd not be doing it. Not sure what you mean by an input buffer. The DAC is inevitable with a digital source, as is an output stage. Of course you are correct that there are THREE DACs and three output stages. My theory is that since these are in parallel rather than in series it doesn't matter. We'll see 🙂
Nah If using DSP go a full 4-Way.
Get the bass into a decent big woofer and the midbass above 80 suddenly becomes clear, cross to the mid around 300Hz and you can then use passive for the mid-tweeter separation.
Get the bass into a decent big woofer and the midbass above 80 suddenly becomes clear, cross to the mid around 300Hz and you can then use passive for the mid-tweeter separation.
Better than 3 way or 2 way....--> 2.5way with lower woofer missing tweeter xo and woofers large enough to keep excursion away from midwoofer with highpass...HE2.75waylol