3-way active crossover - how it works practically

[Baciosa]

Hi everyone,
I’m working on a university assignment and I need to understand the signal path and cabling for a pair of active 3-way loudspeakers. The amplification/DSP I’m referencing is PowerSoft Mezzo 324A (4 channels) + Mezzo 602A (2 channels), so 6 channels total (3 per speaker).

I’d like to confirm that my understanding of the connection order is correct, and ask for best practice to keep the cabling clean in a contract installation.

My understanding (is this correct?)

1. Stereo source (L/R) →
2. Mezzo inputs →
3. Inside the Mezzo: DSP / active crossover (splits into LOW/MID/HIGH for L and R + EQ/delay/limiters) →
4. Inside the Mezzo: power amplification (6 separate amp channels, one per driver) →
5. Outputs to the speakers: 3 amplified lines per cabinet (woofer / mid / tweeter) →
6. Inside each cabinet: direct wiring to each driver (no passive crossover).

Questions

1. Is my idea of the signal flow order above correct for a fully active stereo 3-way using Mezzo units? I'm quite unexperienced so I'm not very sure...
2. For a cleaner look, is it common to run one multi-core speaker cable per cabinet (instead of 3 separate cables) and split internally? If so, which connector approach is recommended (e.g., 8-pole Speakon) and are there typical pinout conventions to avoid mistakes?

Thanks a lot, I'm trying to understand by myself but the more I read the more my doubts increase

 

[TLS Guy]

Hi everyone,
I’m working on a university assignment and I need to understand the signal path and cabling for a pair of active 3-way loudspeakers. The amplification/DSP I’m referencing is PowerSoft Mezzo 324A (4 channels) + Mezzo 602A (2 channels), so 6 channels total (3 per speaker).

I’d like to confirm that my understanding of the connection order is correct, and ask for best practice to keep the cabling clean in a contract installation.

My understanding (is this correct?)

1. Stereo source (L/R) →
2. Mezzo inputs →
3. Inside the Mezzo: DSP / active crossover (splits into LOW/MID/HIGH for L and R + EQ/delay/limiters) →
4. Inside the Mezzo: power amplification (6 separate amp channels, one per driver) →
5. Outputs to the speakers: 3 amplified lines per cabinet (woofer / mid / tweeter) →
6. Inside each cabinet: direct wiring to each driver (no passive crossover).

Questions

1. Is my idea of the signal flow order above correct for a fully active stereo 3-way using Mezzo units? I'm quite unexperienced so I'm not very sure...
2. For a cleaner look, is it common to run one multi-core speaker cable per cabinet (instead of 3 separate cables) and split internally? If so, which connector approach is recommended (e.g., 8-pole Speakon) and are there typical pinout conventions to avoid mistakes?

Thanks a lot, I'm trying to understand by myself but the more I read the more my doubts increase

The bass driver is connected to a low pass filter. The mid range driver is connected to a band pass filter, the tweeter is connected to a high pass filter.

However the trick, and its a difficult one, of designing any crossover, is matching it to the drivers. All speaker drive units have a low end roll off and a top end roll off. In addition they have resonant peaks, and other FR irregularities that the crossover has to deal with. So you need good FR data on each driver.

The next issue is that the drivers will have different sensitivities and you have to match the output of each amp to take that in consideration.

This is an immense subject and designing a speaker that sounds even close to good is not an easy task.

 

[lovinthehd]

Why did you choose the 2ch and 4ch mezzo units particularly instead of a single box that can accommodate dsp/crossover (like a miniDSP unit for example)? Why a 3way speaker instead of a 2way speaker? The path sounds correct generally, tho.

FWIW also this subject more belongs in the DIY subforum here https://forums.audioholics.com/forums/audio/diy-corner-tips-techniques.22/. Asking about how people "unusually" run wiring is a bit odd as there isn't much "usual" about such a setup in home audio. The mentioned Speakon connectors would be a way to do it with a single cable into the loudspeaker, tho.

 

[Baciosa]

Why did you choose the 2ch and 4ch mezzo units particularly instead of a single box that can accommodate dsp/crossover (like a miniDSP unit for example)? Why a 3way speaker instead of a 2way speaker? The path sounds correct generally, tho.

FWIW also this subject more belongs in the DIY subforum here https://forums.audioholics.com/forums/audio/diy-corner-tips-techniques.22/. Asking about how people "unusually" run wiring is a bit odd as there isn't much "usual" about such a setup in home audio. The mentioned Speakon connectors would be a way to do it with a single cable into the loudspeaker, tho.

Thanks for the feedback, and fair questions!


I went with the 4ch + 2ch Mezzo combination mainly because a fully active stereo 3-way needs 6 amp channels total, so that pairing maps cleanly to the requirement without leaving unused channels. I also preferred an integrated platform where DSP (active crossover/EQ/delay/limiters) and amplification are in the same ecosystem, which keeps the signal chain simpler (fewer external boxes and interconnects) and makes system management/presets more straightforward than a separate miniDSP + multiple amps approach.


On the 3-way vs 2-way: the motivation is primarily clarity and headroom. Splitting the workload across three drivers can reduce stress/distortion on each driver in its operating range and can make it easier to maintain clean output at realistic listening levels (with long sessions in mind), even though it adds complexity.

By the way sorrry, It's my first time posting something so I mistook the section...should I delete and repost?

 

[Baciosa]

The bass driver is connected to a low pass filter. The mid range driver is connected to a band pass filter, the tweeter is connected to a high pass filter.

However the trick, and its a difficult one, of designing any crossover, is matching it to the drivers. All speaker drive units have a low end roll off and a top end roll off. In addition they have resonant peaks, and other FR irregularities that the crossover has to deal with. So you need good FR data on each driver.

The next issue is that the drivers will have different sensitivities and you have to match the output of each amp to take that in consideration.

This is an immense subject and designing a speaker that sounds even close to good is not an easy task.

Thanks a lot for the explanation, very clear.


I understand that in a 3-way system each driver is fed through the appropriate filter (woofer = low-pass, mid = band-pass, tweeter = high-pass), and that the real challenge is matching those filters to the drivers’ actual behavior (natural roll-off, resonances, FR irregularities) and their different sensitivities. I am trying my best but since it's quite speculative now I wanted to challenge myself

 

[TLS Guy]

Thanks a lot for the explanation, very clear.


I understand that in a 3-way system each driver is fed through the appropriate filter (woofer = low-pass, mid = band-pass, tweeter = high-pass), and that the real challenge is matching those filters to the drivers’ actual behavior (natural roll-off, resonances, FR irregularities) and their different sensitivities. I am trying my best but since it's quite speculative now I wanted to challenge myself

I will reply to you at length later as you are way adrift at sea.

 

[TLS Guy]

Hi everyone,
I’m working on a university assignment and I need to understand the signal path and cabling for a pair of active 3-way loudspeakers. The amplification/DSP I’m referencing is PowerSoft Mezzo 324A (4 channels) + Mezzo 602A (2 channels), so 6 channels total (3 per speaker).

I’d like to confirm that my understanding of the connection order is correct, and ask for best practice to keep the cabling clean in a contract installation.

My understanding (is this correct?)

1. Stereo source (L/R) →
2. Mezzo inputs →
3. Inside the Mezzo: DSP / active crossover (splits into LOW/MID/HIGH for L and R + EQ/delay/limiters) →
4. Inside the Mezzo: power amplification (6 separate amp channels, one per driver) →
5. Outputs to the speakers: 3 amplified lines per cabinet (woofer / mid / tweeter) →
6. Inside each cabinet: direct wiring to each driver (no passive crossover).

Questions

1. Is my idea of the signal flow order above correct for a fully active stereo 3-way using Mezzo units? I'm quite unexperienced so I'm not very sure...
2. For a cleaner look, is it common to run one multi-core speaker cable per cabinet (instead of 3 separate cables) and split internally? If so, which connector approach is recommended (e.g., 8-pole Speakon) and are there typical pinout conventions to avoid mistakes?

Thanks a lot, I'm trying to understand by myself but the more I read the more my doubts increase

I am going to respond to you at more length now.

The first is an item you have not mentioned. You have to tune any bass driver to the box, be it sealed, ported, TL, or horn. To do this you need reliable data on what are known as the Thiele/Small parameters. Often there is reliable data in the spec. sheet of the driver. This data allows you to assess the optimal mode for loading the driver, and allows you to calculate box volumes, and ports etc. Then you need reliable acoustic data.

Now, as a beginner you don't want to start designing a three way, as that is a much greater design challenge and frequently unsuccessful.

The reason is that you really need a mid driver that will cover the speech discrimination band from at least 400/500 Hz to 3.5 or as high as 5 Khz,. There are very few really good mid range drivers avaialable.

So one crossover point is likely to me much less intrusive than two.

Any crossover, passive or active has to be able to deal with peaks in driver response, which are a frequent occurrence, and other irregularities. Most drivers will show a nasty peaked response as they reach their cone break up mode, and this must be dealt with in the crossover design or the speaker will be a dreadful dog.

These are the high points that confront the designer. It does not matter how fancy the name of your crossover, but these issues have to be dealt with.

At the moment you have to greatly expand your font of knowledge before you are ready to design any speaker.

So study up and really understand the intricacies of speaker design and the challenges that have to be dealt with in every design. Only then can you design the correct box and loading and think how best to integrate drivers with the crossover.