Speaker building final degree project doubts

[audio_04]

Hi again,

First of all, thanks a lot for the advice about drivers so far, it’s been really helpful.

Now I’m starting to look into the electronics side and I’m a bit confused about how to properly integrate amplification, crossover and TWS in the same system.

I’ve been looking at modules like the Wondom JAB2+ (https://store.sure-electronics.com/product/812), which seems quite convenient since it already includes Bluetooth and amplification. The thing is, I’m not sure how the crossover would be handled. From what I understand, if there is no proper crossover built in, I would need separate amplification channels per frequency band.

In that case, I guess I would end up doing something like using one amplifier for the woofers of both speakers and another one for the tweeters of both speakers. But that’s not really what I’m aiming for.

What I actually want is to have two separate speakers (left and right), each one being a 2-way system, and ideally each speaker would handle its own woofer and tweeter internally, while also having Bluetooth and TWS between them.

So basically I’m trying to understand what the “standard” approach is here. Is it better to use a DSP amplifier board in each speaker so the crossover is done there, or is it more common to use a single DSP with multiple amplifiers, or even just go with a passive crossover inside each speaker and keep the amp simpler?

I feel like I’m missing something fundamental in how these systems are usually implemented, so any guidance or example setups would really help.

 

[voodooless]

The thing is, I’m not sure how the crossover would be handled. From what I understand, if there is no proper crossover built in, I would need separate amplification channels per frequency band.

It's a board with built-in DSP. You can use the PC software they offer, or SigmaStudio, to create a crossover. No need for anything external, other than a programmer board.

I don't know if the Bluetooth module supports TWS, though. Edit, ah, it does:

As to how you implement it.. anything is possible. You'll have to come up with the reasoning for picking either of those options.

 

[Arindal]

go up to the RS125 or SIG120-4.

RS125 in my experience has similar issues with breakup/cancellation above 1K, and SIG120 is pretty restricted in terms of bass reproduction (which can be compensated for in an active DSP concept).

CF120 or DS135 make sense in a slightly bigger enclosure.

I used the RS100-8 in an experimental build with the cheap PTmini-6 tweeter.

This tweeter is tempting, but really difficult to handle, and calls for very high crossover frequency and a good directivity strategy. Despite its price, I would leave it to very experienced loudspeaker designers. There are alternatives like AMT mini, or something by Swans or GRS.

The Tang Band W5-1138SMF (5-1/4 inch) is legendary for the bass it can produce in a small box

Absolutely agree, but it depends on what you call a small box, 10l? Particularly vented systems should not be much smaller IMHO with these TB woofers.

 

[Audionaut]

It’s the final year of my degree in Telecommunications Engineering, specialized in Sound and Image Engineering.
For my project, I’m designing and building a pair of active stereo speakers.

It may be that I don’t fully understand the structure of your degree program, but a final thesis—whether for a bachelor’s, master’s, or doctoral degree—should always demonstrate, at whatever level, that you have thoroughly grasped the subject matter and can use that foundation to produce an original piece of academic work.
However, since the beginning of this thread, you’ve been asking questions like a complete beginner to the subject, and it seems as though you’re only just starting to explore this field.

 

[staticV3]

Now I’m starting to look into the electronics side and I’m a bit confused about how to properly integrate amplification, crossover and TWS in the same system.

See post #11 for another option.

 

[audio_04]

You may be able to do all of this with one Up2Cast Amp board per speaker.

Crossover and baffle step correction etc. is programmed using ACPWorkbench, with one channel going to the woofer and one to the tweeter.

The TX Amp receives a Stereo signal from your source device via Bluetooth or SPDIF, then transmits it to the RX Amp via Auracast.

In ACPWorkbench you should be able to configure that one Amp plays only the left channel and the other only right.

I don't own one though, so best to confirm this with customer support first.

Thanks a lot for the suggestion, that actually sounds like a really good option.

I’ve just contacted them to confirm all of this directly, but if everything works as it seems (having built-in crossover through ACPWorkbench and Bluetooth/Auracast to link both speakers) then I think that would basically cover everything I need in a single board.

That would simplify the whole system a lot, so really appreciate the recommendation.

 

[audio_04]

It may be that I don’t fully understand the structure of your degree program, but a final thesis—whether for a bachelor’s, master’s, or doctoral degree—should always demonstrate, at whatever level, that you have thoroughly grasped the subject matter and can use that foundation to produce an original piece of academic work.
However, since the beginning of this thread, you’ve been asking questions like a complete beginner to the subject, and it seems as though you’re only just starting to explore this field.

Hi,

In my degree, most of the focus is actually on room acoustics, environmental acoustics, and noise control, along with the image/signal side. Because of that, the electroacoustics side, especially the practical implementation of loudspeakers and the electronics involved, hasn’t really been covered in depth.

That’s precisely why I chose this topic for my final project. Since most people in my program tend to do projects related to room treatment or acoustic analysis, I wanted to use this opportunity to explore a more practical side that we don’t usually work on, and build a stronger understanding of loudspeaker design and implementation.

So while I may be asking more basic questions, that’s intentional, the goal of this thread is to get an overall sense of how people in the DIY community approach and think about these things.

 

[Penelinfi]

I made a passive TL speaker using rs100-4 and Vifa ox20 in a tiny bevel "waveguide", more than a decade ago. It sounds fine I guess. A little more trebly sounding due to certain factors though design was mostly flat with dip in power response. Bass is ok considering it's mostly a 3" woofer. You do get a little bit of the feeling of three way speaker that's missing the big bass driver, because the little one didn't have any bass bumps to trick you.

The nd91 is better for a bass driver in that size. You can get passive radiators too.

Depends on what you're going for with the speaker. There's trying to make an accurate monitor vs concentrating more on the form factor and functionality - eg small size with decent bass, the tws system, or battery powered etc.