3 way active design sanity check

[tanno1]

Hey,

I am working on a 3-way active speaker design. Below are my drivers, amps, and power supplies. I also included a rough drawing of my design. I am hoping to get feedback on the legitimacy of my design and see if anyone has any advice or input that I may not have considered. Once I get some feedback here, I am going to come up with a more fleshed out version of the electronics diagram and ask for some feedback there.

Also, is it common to have a separate power supply for the subwoofer? They consistently seem to take up way more power and I could not find a power supply that was within my range that would work for all 3 in combination with some buck/boost converters. Not sure if that is bad practice.

Lastly, since I am investing so much into the power supply for the subwoofer, I would be interested in getting a nicer subwoofer if it is wroth it. Based off of frequency curves, I could find another that is a bit flatter, but I am not sure how much it is worth it at this scale.

Drivers:
Subwoofer: GRS 10SW-4 10" Poly Cone Subwoofer 4 Ohm
Midrange: Dayton Audio DC130BS-4 5-1/4" Classic Shielded Woofer 4 Ohm
Tweeter: Dayton Audio ND25FW-4 1" Soft Dome Neodymium Tweeter with Waveguide 4 Ohm

Amps:
Mid/tweeter: Dayton Audio KABM-30M 1 x 30W Bluetooth 5.0 Amp Board with EQ Programing Port
Subwoofer (built in power supply): ICEPower 300AS1 Class D Amplifier Module with Built-In Power Supply 1 x 300W

Power Supply:
Mid/tweeter: Mean Well RSP-150-15

Diagram:

If I am missing any relevant information, let me know.

Thank you.

 

[Keith_W]

It is common for subwoofers to have their own plate amps.

You might get much better help at diyaudio.com. Don't worry, those guys are objectivists as well. No voodoo over there.

 

[AnalogSteph]

What kind of crossover are you planning to use?

Also, is it common to have a separate power supply for the subwoofer?

No, but it may be a worthwhile concession for a one-off DIY design.

I can't say I'm too thrilled with the choice of mid/tweeter amp, 30 W / 4 ohms and 91 dB of SNR translates to about 300 µV worth of noise. Not great when your midrange has a sensitivity exceeding 91 dB / 2.83 V / m... you can expect about 10 dB @ 1 m from that alone, not to mention the mid-treble peak. The tweeter is likely to require some passive attenuation. Consider using a classic Class AB amp instead (some TDA7493 or LM3886 deal).

Do the electronics need to be integrated into the speaker itself? You tend to have more choice among ready-made external amps.

Be sure you consult some actual measurements for your drivers. I remember the ND25FW having a funky double impedance hump that can mess you up when using as much as a series resistor.

Lastly, since I am investing so much into the power supply for the subwoofer, I would be interested in getting a nicer subwoofer if it is wroth it.

That's not even a subwoofer, it's just a classic woofer. A DSP crossover should be able to sort out any remaining issues with flatness (Qts is rather too high even for a sealed enclosure otherwise, let alone BR). This driver is realistically good to about 600 Hz, it should cross over around 300 Hz with ease. It's obviously nothing too special in terms of excursion and power handling and stuff but seems workable enough. Couldn't find anything about the kind of voice coil former.

The midrange has an Al voice coil former, so expect robustness but mediocre electrical distortion. The mid-treble breakup hump may warrant some passive notching action.

Dayton Audio Classic DC130BS-4 - 5.25″ Woofer

5.25″ Woofer, 51 Hz, 60 W, 87 dB, 4 Ω

loudspeakerdatabase.com

Low Distortion Filter for PTT6.5X04-NAA

purifi-audio.com

In terms of potential alternatives, maybe Dayton's SIG150-4? Hmm, Al shorting sleeve and phenolic former, a copper shorting ring and kapton former would be decidedly better. Probably more expensive, too...

 

[Busdriver02]

Active designs always end up costing more. Amp hiss drives more expensive amps, then you don't want to skimp on drivers, etc. etc.

What are you trying to accomplish? There's a difference between building a tower that happens to have a sub in it, and trying to smash all of that into a monitor sized stand mount.

 

[tanno1]

What kind of crossover are you planning to use?


No, but it may be a worthwhile concession for a one-off DIY design.

I can't say I'm too thrilled with the choice of mid/tweeter amp, 30 W / 4 ohms and 91 dB of SNR translates to about 300 µV worth of noise. Not great when your midrange has a sensitivity exceeding 91 dB / 2.83 V / m... you can expect about 10 dB @ 1 m from that alone, not to mention the mid-treble peak. The tweeter is likely to require some passive attenuation. Consider using a classic Class AB amp instead (some TDA7493 or LM3886 deal).

Do the electronics need to be integrated into the speaker itself? You tend to have more choice among ready-made external amps.

Be sure you consult some actual measurements for your drivers. I remember the ND25FW having a funky double impedance hump that can mess you up when using as much as a series resistor.

That's not even a subwoofer, it's just a classic woofer. A DSP crossover should be able to sort out any remaining issues with flatness (Qts is rather too high even for a sealed enclosure otherwise, let alone BR). This driver is realistically good to about 600 Hz, it should cross over around 300 Hz with ease. It's obviously nothing too special in terms of excursion and power handling and stuff but seems workable enough. Couldn't find anything about the kind of voice coil former.

The midrange has an Al voice coil former, so expect robustness but mediocre electrical distortion. The mid-treble breakup hump may warrant some passive notching action.

Dayton Audio Classic DC130BS-4 - 5.25″ Woofer

5.25″ Woofer, 51 Hz, 60 W, 87 dB, 4 Ω

loudspeakerdatabase.com

Low Distortion Filter for PTT6.5X04-NAA

purifi-audio.com

In terms of potential alternatives, maybe Dayton's SIG150-4? Hmm, Al shorting sleeve and phenolic former, a copper shorting ring and kapton former would be decidedly better. Probably more expensive, too...

Wow, thanks for a great response! Firstly, I am planning on building my own crossover. It might be helpful to outline some specifications for this speaker to limit price/quality needs. Currently with the components I have, it is around $360 per speaker and I am fine with that. At or below this price range, I would like to optimize my build to produce the best sound possible. At this point, I don't think I fully understand what that means yet, but I was aiming for flat frequency responses on each of my drivers and that is about it so far.

I am a bit confused about this part. How did you get that noise calculation? Noise is just the standing noise that comes out of a powered speaker right?

I can't say I'm too thrilled with the choice of mid/tweeter amp, 30 W / 4 ohms and 91 dB of SNR translates to about 300 µV worth of noise. Not great when your midrange has a sensitivity exceeding 91 dB / 2.83 V / m... you can expect about 10 dB @ 1 m from that alone, not to mention the mid-treble peak. The tweeter is likely to require some passive attenuation. Consider using a classic Class AB amp instead (some TDA7493 or LM3886 deal).

For electronics, I am trying to implement everything inside the enclosure which I am designing with the help of WinSD. I want these to be standalone speakers that can sit on my desk, even though they might be heavy.

As for the subwoofer part, I was planning on setting the crossover at 300Hz. I am going to reread this reply in the morning and research some of the other things you are mentioning as far as coil material and the mid-treble peak, this is a new world for me and I really appreciate the time you put into this reply. Thank you.

 

[Busdriver02]

I want these to be standalone speakers that can sit on my desk, even though they might be heavy.

If your thought is these will live on your desk, is it fair to say you'll mostly be listening to these while sitting at your desk? A 10 inch is pretty big to put on a desk, are you thinking putting the sub under the desk?

I'm asking all this, because I think the idea of what you want to build isn't the same as what most folks think when they read "3-way active design."

 

[tanno1]

If your thought is these will live on your desk, is it fair to say you'll mostly be listening to these while sitting at your desk? A 10 inch is pretty big to put on a desk, are you thinking putting the sub under the desk?

I'm asking all this, because I think the idea of what you want to build isn't the same as what most folks think when they read "3-way active design."

I currently have a pair of M1 Active Alesis' on my desk. I have a desk made of a standard sized door, so it is pretty large. They have a 6.5" woofer so I honestly might size everything down quite a bit the more I think about this. They are also two way, and I am considering just doing a two way setup for cost and size.

As for the 3 way active design, my understanding is that an active speaker has the crossover placed before the amp, and it is all inside of the speaker as one complete unit. With active speakers, I just plug in my power and audio, and I am ready to go. Is that not correct?

 

[AnalogSteph]

Firstly, I am planning on building my own crossover.

Your own custom active XO? I have a feeling this is gonna be rough. You can expect some development time there. And then we haven't even talked about the enclosure.

Currently with the components I have, it is around $360 per speaker and I am fine with that. At or below this price range, I would like to optimize my build to produce the best sound possible.

I hope you're not doing this to save money.

I am a bit confused about this part. How did you get that noise calculation?

Rated power output is
Vnom = √(30 W * 4 Ω) ~= 10.95 Vrms
Hence 91 dB below that we get
Vnoise = Vnom * 10^(-91/20) ~= 308 µVrms
That's the first part. As it happens, I have a decent idea about the noise level out of 88 dB / 2.81 V / m speakers from an amp rated 85 W / 8 ohms and 100 dB, which is actually a bit lower yet still quite perceptible at 1 m.

You can also calculate SPL given that we know midrange output is Sens = 91.6 dB SPL / 2.83 V / m:

Dayton Audio - DC130BS-4 5-1/4" Classic Shielded Woofer 4 Ohm

DC130BS-4 5-1/4" Classic Shielded Woofer 4 Ohm

www.daytonaudio.com

SPLout = Sens + 20log(Vnoise/2.83 V) ~= 91.6 dB SPL - 79.3 dB
~= 12.3 dB SPL @ 1 m
(Add 20 dB for comparison to the monitor "hiss list" @ 10 cm - I can tell you that 32.3 dB would be quite appalling and is mostly found on speakers with large typical listening distances. The KRK Rokit RP10-3 comes to mind.)

Pure white noise tends to become audible in a quiet room at around 4 dB SPL.
The mid-treble peak was from measurements here:

Dayton Audio Classic DC130BS-4 - 5.25″ Woofer

5.25″ Woofer, 51 Hz, 60 W, 87 dB, 4 Ω

loudspeakerdatabase.com

Right around 4-5 kHz where our ears are the most sensitive.

I want these to be standalone speakers that can sit on my desk, even though they might be heavy.

On your desk? I mean, it could work out dimension-wise as a 10" is about the height of typical desk stands as required to get things to ear height, but you may have a hard time matching the midrange-tweeter spacing of commercially available 5" class nearfield monitors, many of which are even sporting cutouts to either driver in an effort to minimize it.

You may want to consider going with some of the rather plentiful decent inexpensive 5" class monitors and only DIY the (sub)woofer portion with crossover, phase adjustment and balanced I/O to go with them. It would reduce the scope of this project from a massive undertaking to something a lot more realistically manageable.

EDIT:

I currently have a pair of M1 Active Alesis' on my desk. I have a desk made of a standard sized door, so it is pretty large. They have a 6.5" woofer so I honestly might size everything down quite a bit the more I think about this.

These?

They are clearly not designed as nearfields with that kind of massive driver spacing (they may not integrate too well at typical desk listening distances of ~0.8 m yet), and much different from the M1 Actives that Alesis are selling today. Those are cheap 5" powered speakers with passive crossover, so not even actually deserving of the name "Active". Either way, a lot has happened in the market in the last 25 years. You can pick up some Kali IN-8v2s at $399 a pop ready to go, a 3-way with 4"/1" coaxial mid/tweeter and 8" woofer. Not the world's best 8" woofer, mind you, but...

 

[tanno1]

Your own custom active XO? I have a feeling this is gonna be rough. You can expect some development time there. And then we haven't even talked about the enclosure.

I hope you're not doing this to save money.

Rated power output is
Vnom = √(30 W * 4 Ω) ~= 10.95 Vrms
Hence 91 dB below that we get
Vnoise = Vnom * 10^(-91/20) ~= 308 µVrms
That's the first part. As it happens, I have a decent idea about the noise level out of 88 dB / 2.81 V / m speakers from an amp rated 85 W / 8 ohms and 100 dB, which is actually a bit lower yet still quite perceptible at 1 m.

You can also calculate SPL given that we know midrange output is Sens = 91.6 dB SPL / 2.83 V / m:

Dayton Audio - DC130BS-4 5-1/4" Classic Shielded Woofer 4 Ohm

DC130BS-4 5-1/4" Classic Shielded Woofer 4 Ohm

www.daytonaudio.com

SPLout = Sens + 20log(Vnoise/2.83 V) ~= 91.6 dB SPL - 79.3 dB
~= 12.3 dB SPL @ 1 m
(Add 20 dB for comparison to the monitor "hiss list" @ 10 cm - I can tell you that 32.3 dB would be quite appalling and is mostly found on speakers with large typical listening distances. The KRK Rokit RP10-3 comes to mind.)

Pure white noise tends to become audible in a quiet room at around 4 dB SPL.
The mid-treble peak was from measurements here:

Dayton Audio Classic DC130BS-4 - 5.25″ Woofer

5.25″ Woofer, 51 Hz, 60 W, 87 dB, 4 Ω

loudspeakerdatabase.com

Right around 4-5 kHz where our ears are the most sensitive.

On your desk? I mean, it could work out dimension-wise as a 10" is about the height of typical desk stands as required to get things to ear height, but you may have a hard time matching the midrange-tweeter spacing of commercially available 5" class nearfield monitors, many of which are even sporting cutouts to either driver.

You may want to consider going with some of the rather plentiful decent inexpensive 5" class monitors and only DIY the (sub)woofer portion with crossover, phase adjustment and balanced I/O to go with them. It would reduce the scope of this project from a massive undertaking to something a lot more realistically manageable.

I am trying to learn about electronics, audio, and product development. I am a mechanical engineer and I have history designing PCB boards and mechatronics projects. I do expect this to take some time and I am not stuck to this design at all, I am fully willing to adjust it. I think I am going to reduce it down to a 2-way active with a full range and a tweeter as I learn more.

I think I am starting to get what you are saying about the rated power output. If I have larger drivers, they have larger listening distances, so having them on my desk would be quite miserable. For a pair of desktop speakers, I see pairs like the KRK Rokit 8 with an SPL of 109db @ 1m, which is higher than 88 db/watt/m for an 8 ohm speaker, so is that hiss going to be present in those? I have listened on those speakers before and it has sounded pretty good.

This is a project I was referencing in the early design work, although this guy had an external amp, and I want mine to have that inside the enclosure. https://courses.physics.illinois.edu/phys406/sp2017/Student_Projects/Spring12/Alex_Kulyk_P406_Project_Report_Sp12.pdf

I'm gonna hit the drawing board again and revise my plans. I'll post the update here and ask for some feedback, once again, thank you for the expertise and advice.

 

[AnalogSteph]

I think I am going to reduce it down to a 2-way active with a full range and a tweeter as I learn more.

Not a bad idea.

If I have larger drivers, they have larger listening distances, so having them on my desk would be quite miserable.

Driver spacing is one reason why some people swear by point source speakers like coaxes... although these are a huge can of worms and extremely hard to get right, and if you don't they can have super erratic dispersion. KEF is one of the few manufacturers who have managed to tame them after decades worth of improvements. The Kali koaxes are decent but not in the same league. There's also the category of "pseudo-coax" arrangements like the Genelec Ones with their pair of racetrack woofers firing out on the top and bottom behind a central mid/tweeter coax (some of the most advanced speakers in the world at this time). Some manufacturers also have coaxes with stick-out tweeters, e.g. Fluid Audio FX series, and ME Geithain does the whole baffle with midrange and tweeter mounted in front of a woofer thing quite a lot, aside from having pioneered cardioid bass (several high-end speaker designs are also doing that these days... Kii Three, Dutch & Dutch 8C, Mesanovic etc.).

Size alone is not a criterion when it comes to how well speakers will work in nearfield... driver spacing, time alignment and crossover frequencies and steepness play a major role, alongside noise levels. You could easily use Neumann KH420s like that, even if it seems silly to have midfield monitors for 10 grand the pair twiddle their thumbs in boredom on a desk (not to mention the 120 W of idle power consumption for both).

see pairs like the KRK Rokit 8 with an SPL of 109db @ 1m, which is higher than 88 db/watt/m for an 8 ohm speaker, so is that hiss going to be present in those?

You're mixing up totally different specs. 109 dB / 1 m probably is the maximum output level spec for these, not their input sensitivity! Manufacturers of these lower-end monitors tend not to publish input sensitivity figures very often. In any case an active speaker is pretty much a "black box" that can have almost arbitrarily high or low sensitivity without it telling you anything about the drivers... there's power amps, crossovers, level trims and input circuitry in between. You have to go to the pros to get actual sensitivity specs, e.g. Neumann (dB SPL @ 1 m for 0 dBu in) or Genelec (dBu in for 100 dB SPL out @ 1 m).

But yes, the larger KRKs have a reputation for being hissy... the RP5 was the only G4 to be nice and quiet, I hope this also applies to the G5.

BTW, I have to wonder why they keep making 8"/1" models with little to no waveguide action on the tweeter. You just can't match the directivity of such a combo very well, so sound in diffuse field is always going to be distinctly colored if they are flat on axis and vice versa. You can EQ them flat on axis, listen in nearfield and hope that a heavily sound treated studio will absorb most of the off-axis radiation, which I guess may be the modus operandi for these. Whenever you find an 8"/1" that doesn't kind of look like a Behringer B2031A, be wary. Even the ND25FW seems a bit too wide for a 7" (180 mm) woofer already...

Introducing Denotiva DIY speakers!

Well was planning to wait until a later date to announce this, but the budget Directiva project required that I exchange the Seas DXT tweeter and so it seemed the time had arrived. To date all Directiva speakers have used the DXT tweeter but as I worked on a budget version I realized that the...

www.audiosciencereview.com

 

[Busdriver02]

my understanding is that an active speaker has the crossover placed before the amp, and it is all inside of the speaker as one complete unit. With active speakers, I just plug in my power and audio, and I am ready to go. Is that not correct?

I would think most folks would call that a powered system. Active speaker would normally mean a digital signal processor followed by individual per channel amplifiers. I suppose you could argue that an analogue (op amps and whatnot), powered cross over could be active. In any event, it opens up possibilities that can't be done with a passive crossover (only inductors and capacitors).

If what you are really after is a self powered system that sits on your desk and connects to your computer/phone/streamer, I'd look into a 2.1 desktop amp and passive bookshelf speakers and a sub to go under the desk. Something like the Fosi BT-30 should be plenty of power to do near field desktop duty. That will also free up a lot of your budget to spend on speakers.

Prioritize your money on the desktop speakers, then spend on subwoofer after that. The 6 inch version of the woofers below got a good review from Erin's audio, and the SB19 has a good rep for bang for the buck tweeter.

Quick wag on bill:
Amazon--BT-30D Pro amplifier $110
Madisound--SB Acoustics SB19ST Tweeter $24 x2
Madisound--SB Acoustics SB15CAC30 5" Woofer $100x2 or SB12CAC25 4" Woofer $75 x2
Parts-Express--Dayton 6.5" Classic Subwoofer $50

I would lean towards the 4 inch woofer to get closer center to center driver spacing and dispersion matching (Analogsteph's points)
The .23 and .56 cubic foot flat pack enclosures on PE could be made to work (glue some blocks inside to shrink the volume). $100

That leaves $200 in your original component budget for odds and ends (terminal cups, port tubes, paint, screws, etc) and the crossovers parts.

 

[AnalogSteph]

I would think most folks would call that a powered system. Active speaker would normally mean a digital signal processor followed by individual per channel amplifiers. I suppose you could argue that an analogue (op amps and whatnot), powered cross over could be active. In any event, it opens up possibilities that can't be done with a passive crossover (only inductors and capacitors).

Powered = integrated power amp, passive XO (including the dreaded single capacitor variety found on so many budget wannabe "monitors")
Active = integrated analog or DSP crossover and power amp
Both handle fundamentally the same, the differences are purely internal. A powered speaker basically is just a speaker and an amplifier mashed together.

There are quite a number of active speakers with traditional analog active crossovers still - Genelec 80xx, Neumann KH120 (the old one, not the II), KH310, KH420, Yamahas, Focals, Dynaudios, ...

 

[Busdriver02]

Powered = integrated power amp, passive XO (including the dreaded single capacitor variety found on so many budget wannabe "monitors")
Active = integrated analog or DSP crossover and power amp

Agree, this is what I was trying to say.

 

[tanno1]

These?

They are clearly not designed as nearfields with that kind of massive driver spacing (they may not integrate too well at typical desk listening distances of ~0.8 m yet), and much different from the M1 Actives that Alesis are selling today. Those are cheap 5" powered speakers with passive crossover, so not even actually deserving of the name "Active". Either way, a lot has happened in the market in the last 25 years. You can pick up some Kali IN-8v2s at $399 a pop ready to go, a 3-way with 4"/1" coaxial mid/tweeter and 8" woofer. Not the world's best 8" woofer, mind you, but...

Yes, these are the ones I use. I have used them for years. They are a reference for what I am trying to replace because they have started to wear out. Good to know that they aren't even a good speaker to use haha.

 

[tanno1]

Powered = integrated power amp, passive XO (including the dreaded single capacitor variety found on so many budget wannabe "monitors")
Active = integrated analog or DSP crossover and power amp
Both handle fundamentally the same, the differences are purely internal. A powered speaker basically is just a speaker and an amplifier mashed together.

There are quite a number of active speakers with traditional analog active crossovers still - Genelec 80xx, Neumann KH120 (the old one, not the II), KH310, KH420, Yamahas, Focals, Dynaudios, ...

Gotcha, sounds like I was wrong. My goal is not 3 way active speakers, I want to make powered speakers with a passive XO then. An active XO is just an analog crossover that is powered so that it can be adjusted right?

 

[tanno1]

I would think most folks would call that a powered system. Active speaker would normally mean a digital signal processor followed by individual per channel amplifiers. I suppose you could argue that an analogue (op amps and whatnot), powered cross over could be active. In any event, it opens up possibilities that can't be done with a passive crossover (only inductors and capacitors).

If what you are really after is a self powered system that sits on your desk and connects to your computer/phone/streamer, I'd look into a 2.1 desktop amp and passive bookshelf speakers and a sub to go under the desk. Something like the Fosi BT-30 should be plenty of power to do near field desktop duty. That will also free up a lot of your budget to spend on speakers.

Prioritize your money on the desktop speakers, then spend on subwoofer after that. The 6 inch version of the woofers below got a good review from Erin's audio, and the SB19 has a good rep for bang for the buck tweeter.

Quick wag on bill:
Amazon--BT-30D Pro amplifier $110
Madisound--SB Acoustics SB19ST Tweeter $24 x2
Madisound--SB Acoustics SB15CAC30 5" Woofer $100x2 or SB12CAC25 4" Woofer $75 x2
Parts-Express--Dayton 6.5" Classic Subwoofer $50

I would lean towards the 4 inch woofer to get closer center to center driver spacing and dispersion matching (Analogsteph's points)
The .23 and .56 cubic foot flat pack enclosures on PE could be made to work (glue some blocks inside to shrink the volume). $100

That leaves $200 in your original component budget for odds and ends (terminal cups, port tubes, paint, screws, etc) and the crossovers parts.

Ideally I want to put everything in one box and have it on my desk/above my desk, I am really aiming to showcase this as a product development project with some intermediate electronics work. I will check out these Madisound drivers and likely have some more comments on it later, I am a bit busy today so don't have enough time to work on this. Very thankful for you and AnalogSteph though, the knowledge you guys have is insane haha. Thanks!

 

[tanno1]

My current audio setup has always sounded good to me but it might be comically clapped: I have a Focusrite scarlett solo for my interface, and that has pushed audio to my left and right M1 Active Alesis which are positioned one on my desk, and one on this shelf behind my desk about 1.5' above my monitors.

 

[Busdriver02]

a product development project

House of quality then; you need to prioritize your wants/needs for this project.

If you have your current speakers setup at different heights/distances from your seat, then you have some experimental learning to do. Set your current speakers up in an equilateral triangle with your seating position and all at the same height. Start with the triangle legs pretty close, probably either side of your computer monitor. Then listen, then slide your chair back and listen, then widen the speakers all the way out, then listen, then slide your chair back in, etc. Have the speakers pointed directly at your chair fro this. Listen for things that are different between the various setups, what you like and don't like.

Active, Digital X-Over is a computer chip
Active, Analog X-Over Design:

Passive X-Over:

 

[tanno1]

hey @Busdriver02 @AnalogSteph. I am back with some updates to my design and some clarifying Qs. Here is my updated part list, all subject to change.

Drivers: Dayton Audio PA130-8 5" Full Range PA Driver, Dayton Audio ND25FW-4 1" Soft Dome Neodymium Tweeter with Waveguide 4 Ohm

Amps: Dayton Audio KAB-250v4 2 x 50W Class D Audio Amplifier Board with Bluetooth 5.0

PSU: Mean Well LRS-150-24 24V 6.5A 150W Regulated Switching Power Supply

XO:
Designing based off of the process used in the following link. I am not yet concerned with the XO, (maybe not smart), but it doesnt seem fully relevant until I define what I am going to have it feeding audio into, so the drivers and amps seem of the most importance right now: https://www.ti.com/lit/ug/tidu035/t...69574&ref_url=https%3A%2F%2Fwww.google.com%2F

Now for some questions:
1. Is it valid to use that amp or should i use bi-amping. It should provide 2 x 30W @ 8ohms according to what I read online, and the full range has a RMS wattage at 50W. That should still work for medium volume home listening, and I would be fine making that compromise to use one amp, but I don't know if that defeats the purpose of the XO splitting the signal to use differently spec'd amps for each driver.
2. PSU for the XO. How are these active analog crossovers usually powered? Is there any standard?
3. I calculated 436 µVrms, and 11.97 dB SPLout, adding 20 for the "hiss list" is 31.97 dB @ 1m for the full range driver. This is pretty close to what you calculated for the first set, which had a much larger diameter for the "subwoofer". Am I making a poor decision choice somewhere, or why is this so high?

That seems like a good start. Apologies for anything that might be easy, I am incredibly overwhelmed with information about speaker design and am having to learn to make compromises, but I will get this project done even if it is slow.

 

[tanno1]

Reading through the XO design document, it seems to be extremely dependent on the actual drivers I get and their decibel response with respect to frequency. Once I get drivers, I will start testing them in my room and designing the XO.