3-way to active - Hypex FA253 - learning project

Plug these numbers into the F0 and Q0 in the LT, then drop in your desired end state parameters into the F1 and Q1. In this case 40hz and 0.71.
Ok, starting to make sense. But what are the desired parameters? What is f1? Is this the f where I want the peak of the boost to be? The start of the boost? End of the boost?

And what is the difference of using LT vs achieving about the same curve by using shelves?
 
You're using the LT to fake a different response curve. Hypothetically, you could put a driver into an enclosure that's too small.

Here's an example: The SB15NBAC 5 " in a 1.66L enclosure. You can see the freq and QTC at the bottom. Notice the bass bump around 180hz and then a steeper fall off.
1735425207056.png


Lets say I want a 0.7 QTC shaped slope. (Note: this is largely personal preference, room size you plan to use this in, how close to the front wall, etc).
So let's look at the below. You see the humped curve and then two that look pretty similar. The blue one is an LT applied to the small enclosure (F1 of 82, Q1 of 0.7). The green one is the driver in a 4.5L enclosure and no filters, just the driver response. Using the LT to get the response costs power and excursion (xmax)
1735426006624.png

If you have a lot of xmax to play with, you can also get away with lowering the F1 as well. Below I dropped F1 down to 40hz. The kicked with this particular driver is that with the red curve LT, this driver will hit xmax at 30hz and 1 watt average signal. If you then pull up the amplifier apparent load power, and you'll see at 30hz, the boosted signal is actually 60 VA (volt-amps, watts for all intents).
1735426239608.png
 
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At the above If you have a look at post 12 and the third thumbnail image. At the top left hand of the screen it shows the parameters input fields. You have a very much later software version maybe it has changed and that's why you cannot find it
 
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Step 2 of the conversion is on.

Final list of drivers:

Tweeter: SB Satory 29mm soft dome neodymium version 8 ohm
https://sbacoustics.com/wp-content/uploads/2020/05/SATORI-TW29DN-B-8.pdf
Non neodymium version would do, too


Mid: SB Satory 5in paper black 4 ohm mid or midwoofer (4ohm versions to closer match sensitivity between the other drivers
https://sbacoustics.com/wp-content/uploads/2021/01/5in-SATORI-MW13P-4.pdf
Or
https://sbacoustics.com/wp-content/uploads/2021/01/5in-SATORI-MR13P-4.pdf

Woofers: pair of Dayton Epique 5.5in
https://www.daytonaudio.com/images/resources/295-102--epique-e150he-44-spec-sheet.pdf
 
Sensitivity of the mid doesn't matter. You have individual amp channels for each. In either case, your woofers are going to be your volume limit (either amp power or driver excursion). Either driver is fine.

Having individual channels and being able to run whatever driver you want is one of the cool things with an active system. Like using a subwoofer as a woofer. Which is fun (I have a set I built with 8 inch subs as the woofer).

Incidentally, what led you to choosing those drivers?
 
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I have a fixed box with only about 10L available for the bass section, so was looking for drivers that will work in that and the Daytons seem to be a perfect (and the only) match. And they fit on the front baffle, relatively affordable, have high excursion and power.
I did simulations against a few alternatives and the Daytons won hands down.

For mid and tweeter, just went with mid-tier from SB as a brand of good quality and value for money and having full spectrum of drivers available. Initially I shortlisted their 5in carbon drivers, but Daytons turned out a better match.

Early screening was on size to fit on front baffle.

I also looked at coaxials but did not find affordable ones with good specs.
 
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I understand the Epique drivers. I was more curious about the tweeter and midrange. Given the price point you're dabbling in, I would have picked different is all.

For your consideration:
Tweeter: Seas 27BCD Link
This has a small waveguide which helps with off axis performance. Compare the 60 degree off axis lines.
It's also less expensive, winning.

Midrange(s): Seas CA15RLY Link; Seas ER15RLY Link; SB SB15CAC Link SB SB15NBAC Link
The Satori drivers with Papyrus cones all have a dip between 1 and 2 khz on SB's published responses. If you note the corresponding impedance line, it's a resonance/diffraction thing. I think it's the interaction between the spider and cone, and paper drivers are more suspectable, but I"m speculating. In any event, the Satoris are just really pronounced. The two Seas drivers I listed are paper, the SBs are both metal cones. All look better to me than the Satoris. All are less expensive.

I'm basing my pricing thoughts on what these things cost in the US. But Seas is european, so it should be close for you.
 
I did look at the two SB mids but for no particular reason did not want a metal cone. Maybe I should want a metal cone.

I also did not want a white driver, so did not consider the white one at all.

The two Seas mids are larger than the Satoris I picked. Seas has smaller ones that would be more equivalent on size.

The Satoris on paper look more advanced/modern (vented poles, copper sleeves) and the Seases look older specs. The overall smoothness of the response looks largely similar, but the 1k dip on the SBs is indeed pronounced.

Re tweeter: I would like a waveguide, but the advice seems to be the WG diameter should be as large as the mid driver diameter to be beneficial, and I did not find any that are that large. I also think I want a soft tweeter, but I have no objective substantiation for that.
 
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Keep in mind the driver size "on the box" is related to the outside diameter of the frame, not the diameter of the hole in the baffle. As an example, the Seas drivers above have the same cutout (within 1mm) as the Satori drivers you picked. In any event, if you want the Satori I don't think you'll dislike it or anything.

If you're picking a waveguide to print from the thread on this forum, then that is what I'd do to pick one.
That said, you can look at the frequency response curves and see that the smaller waveguides are working.
 
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I think you're going the wrong direction on driver price for a first project!

Link to Data Here's some data on the SB17CAC 6 inch driver. Take a look at his conclusion part, basically very low distortion. This driver should have the same construction as the smaller SB driver (both black and white). So basically, I would need something to tell me to spend more than this on a driver.

Another link Check this out. His test data is quite old. But most of these are still in production. Note his comments on the SB15NRX.
 
Overall much more sensible choices!
If that mid works for your plans size wise, I have no inputs.

If you're deadset on a softdome tweeter, I'd say that's a more sensible choice. The lumpiness between 10 and 20k is common with 1 inch softdomes on waveguides. Note the dip at 12khz that drops down in frequency as you move off axis. Don't try to EQ this with your amp. It's cancellation inside the waveguide. You won't be able to hear it really anyways, best bet is to ignore it.
 
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I agree that those are nice drivers, and very appropriate for the scope and intentions of this project. I used the SB26STWGC in a project recently and I was impressed with the performance and sound.

Link to 3-way project
1735947245890.png


I considered the SB12MNRX-2 midrange driver for this project, I think it has a lot of performance for money. Ultimately I selected a different driver for the midrange, but I would have been happy with the SB12MNRX-2.

j.
 
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I also like SB26STAC in Waveguide.

I suggest you in speaker building learn how to crawl before you try to fly.
Going straight to building 3 way before you have tried a couple 2 ways is IMO the wrong path.

I also suggest you more or less spend absolute minimum time in Hypex HFD.
(Software is tiring to use and filled with non logical functions)

It is way better use of time to build measure turntable and learn basics of VituixCAD. After some time you may learn how few and simple corrections is needed to complete alter sound signature. Many many iterations is possible with just a 2 way.
 
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Yes, crawl, walk, run…
First, I have added a dsp amp to a passive two-way.
Step 2 will be replacing the drivers and strengthening the box (as a 3-way active). Learning VituixCAD will be part of it.
Only then I may try to design and build a speaker from scratch. I have not landed on a concept for that yet.
 
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