Speaker building final degree project doubts

[audio_04]

Hi!
I am a student and I’m currently working on my final degree project and my goal is to design and build a pair of 2-way speakers. Right now I’m trying to choose suitable drivers for the woofer and tweeter.

For the woofer, I’ve been looking at the RS-100, but I’m not completely sure how to pair it with a tweeter, since it seems more like a full-range driver. So I’m a bit confused about how to properly implement a 2-way system with it.

I also wanted to see if anybody had any recommendations for drivers or general advice on going active (separate amplification + active crossover for each way).

My idea is to make them fully active and wireless, with TWS (so both speakers connect via Bluetooth without needing a cable between them), including amplification and crossover for both drivers.

Any tips or guidance would be really appreciated!

 

[voodooless]

Final year of what? What’s the budget? What are the other requirements and constraints? What is the intended use? What are the success factors?

Seems like these things should be mostly defined before searching for drivers.

 

[Timcognito]

If you have not visit the DIY forum also type Two Way, 2way, two-way, in the search box w&w/o titles only you will be buried in information, tips and were to find components.
Welcome

 

[audio_04]

Final year of what? What’s the budget? What are the other requirements and constraints? What is the intended use? What are the success factors?

Seems like these things should be mostly defined before searching for drivers.

Hi!
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. Each speaker will be a 2-way system (woofer + tweeter), and the idea is that both speakers work wirelessly using TWS (so no cable between them). There's really no limits from the university, nor requirements, other than my own interests. So this is what I came up with:
In terms of requirements:

• Fully active design (separate amplification + crossover for each driver)
• Bluetooth input + TWS between speakers
• Around 60–80 W RMS per speaker (not really sure about this one)
• Target frequency response roughly 55 Hz – 20 kHz
• Intended for near-field / home listening (room use, not PA)

Budget-wise, I’m aiming for around 600–650€ total, including drivers, amplification, Bluetooth/TWS modules, and enclosure materials.

The main goal is to achieve a reasonably flat frequency response and good stereo performance, while also learning the full electroacoustic design process (driver selection, enclosure design, amplification, etc.).
I do have the equipment and help for the messurements of the drivers (this is will take place at the anechoic room of the campus).
I hope this is helpful to understand the project better, and any advice on driver selection or active implementation is welcome!

 

[kemmler3D]

Hey, welcome to ASR. Are you familiar with the concepts of directivity and "beaming"? These are important to the tweeter question. Distortion would also be another reason to use a tweeter instead of running the RS-100 full range.

Getting TWS in there should be the easy part. Before choosing drivers you need to decide on your intended sound quality goals: frequency range, maximum SPL, acceptable distortion, etc. This will dictate the rest of the design.

You can just stick a couple 4" full range drivers in a box and get a speaker that sounds good compared to your phone's speaker. Depending on what course this project is for, you might get full credit for that.

But if you want an actual hi-fi speaker, you have to account for many variables. Definitely check out some of the kits/ plans in the DIY forum, especially the Mechano series... You'll start to see what I mean.

 

[DVDdoug]

I always recommend getting speaker design software. WinISD is free. You enter the (potential) woofer's Thiele-Small parameters and the software helps you to optimize box size and port dimensions or it can model a sealed box, which is sometimes better depending on box size and speaker parameters.

Or, there is more advanced software for designing/modeling a full speaker with tweeter and crossover.

I also wanted to see if anybody had any recommendations for drivers.

You're not going to get "serious bass" from a tiny woofer but as a "designer" you shouldn't be graded on that.

My idea is to make them fully active and wireless, with TWS (so both speakers connect via Bluetooth without needing a cable between them), including amplification and crossover for both drivers.

I also believe that's not the responsibility of the "designer". If I'm right about that, I'd recommend building a regular passive speaker with a passive crossover. You don't want to get bogged-down by something that you won't be graded on. After you get your degree you can upgrade the speakers to wireless active for your personal use.

 

[Arindal]

For the woofer, I’ve been looking at the RS-100, but I’m not completely sure how to pair it with a tweeter, since it seems more like a full-range driver. So I’m a bit confused about how to properly implement a 2-way system with it.

I have quite some experience with Dayton drivers, and many of their units being marketed as fullrange, actually make pretty decent midrange drivers. The RS-100/4 (I guess you are referring to the 4Ohm Aluminium derivate) is not perfect in the 2-4K region, but despite from that pretty versatile working with any lowpass filter design and crossover frequency (which makes it an excellent choice for tiny specialty tweeters like Mini AMT).

For a 2-way non-DSP concept, it is actually pretty difficult to bring them to satisfactory lower bass reproduction. That is a problem you will encounter with lots of midwoofers of the 4" category, my guess would be they are made for active concepts with low resonance frequency and DSP boost in mind. If you master the latter, keep in mind you need lots of power and a good strategy for frequency-selective limiting.

A 2-way concept with a 5.25" midwoofer is definitely more promising in terms of low bass reproduction and easier to build, but requires more enclosure volume.

Distortion would also be another reason to use a tweeter instead of running the RS-100 full range.

I did not notice issues with distortion, except for obvious limitations taking diaphragm area and excursion limits into consideration. Even narrowing directivity above 5K is much smoother compared to other drivers of this category (other Daytons, TB, Jordan, Mark and alike).

 

[voodooless]

The RS-100 will not really get you down to 55Hz reliably, I think.

An interesting option might be a subwoofer driver and a wideband driver. Check out Tangband for small sub drivers, and SB65 for a nice wideband driver. The sub will need some power, though, so specs the amps accordingly. Have a look at Wondom/Sure. They have all kinds of stuff that is DIY friendly. Not top of the line, but inexpensive and probably good enough.

And above all, design, engineer, simulate and measure!

 

[dfuller]

I always recommend getting speaker design software. WinISD is free.

WinISD is very limited compared to, say, vituixCAD - also free.

 

[Arindal]

Check out Tangband for small sub drivers, and SB65 for a nice wideband driver.

I agree for the SB 65, but it requires pretty high x-over freq, not ideal for external subwoofer, and the usable listening window above 8K is pretty restricted with a tiny fullrange. Alternative would be Dayton PC83, pretty underrated driver and easy to cross over.

Which compact TB sub driver would you recommend?

 

[staticV3]

Hi!
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. Each speaker will be a 2-way system (woofer + tweeter), and the idea is that both speakers work wirelessly using TWS (so no cable between them). There's really no limits from the university, nor requirements, other than my own interests. So this is what I came up with:
In terms of requirements:

• Fully active design (separate amplification + crossover for each driver)
• Bluetooth input + TWS between speakers
• Around 60–80 W RMS per speaker (not really sure about this one)
• Target frequency response roughly 55 Hz – 20 kHz
• Intended for near-field / home listening (room use, not PA)

Budget-wise, I’m aiming for around 600–650€ total, including drivers, amplification, Bluetooth/TWS modules, and enclosure materials.

The main goal is to achieve a reasonably flat frequency response and good stereo performance, while also learning the full electroacoustic design process (driver selection, enclosure design, amplification, etc.).
I do have the equipment and help for the messurements of the drivers (this is will take place at the anechoic room of the campus).
I hope this is helpful to understand the project better, and any advice on driver selection or active implementation is welcome!

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.

 

[levimax]

WinISD is very limited compared to, say, vituixCAD - also free.

+1 VituixCad, the learning curve is steep but the documentation is pure gold. It walks you through every step of the design process in exhaustive detail. https://kimmosaunisto.net/Software/VituixCAD/VituixCAD_help_20.html

 

[voodooless]

external subwoofer,

It can be in one box, obviously. So two boxes total, each with the 2 drivers, like any 2-way system.

 

[Arindal]

So two boxes total, each with the 2 drivers, like any 2-way system.

In this case higher crossover freq should not be a problem.

 

[voodooless]

Which compact TB sub driver would you recommend?

No idea at the moment. It will depend highly on budget constraints, available volume and a few other parameters. Simulation is your friend!

You may also want to go though these:

Items about: Voice Coil Test Bench - p 1

audioxpress.com

 

[a4eaudio]

...For the woofer, I’ve been looking at the RS-100, but I’m not completely sure how to pair it with a tweeter, since it seems more like a full-range driver. So I’m a bit confused about how to properly implement a 2-way system with it.

The RS-100 is a great budget driver. You can cross it over to a tweeter anywhere from 2-5kHz, so there are a LOT of tweeters to choose from. The Dayton Audio Reference Series drivers are small for their nominal size, so the RS100 is closer in size to other drivers listed as 3-1/2 inch drivers. If that matters, go up to the RS125 or SIG120-4.

The RS-100 will not really get you down to 55Hz reliably, I think.

I used the RS100-8 in an experimental build with the cheap PTmini-6 tweeter. I got an F3 around 52Hz and produced plenty of bass for a small room. It even sounded fine at modest volume in a hotel conference room at a DIY event - people were putting their hand behind the port laughing at the air pumping out.

...Check out Tangband for small sub drivers...

...Which compact TB sub driver would you recommend?

The Tang Band W5-1138SMF (5-1/4 inch) is legendary for the bass it can produce in a small box and widely used in the "Voxel" project designed by Paul Carmody. The larger 6" W6-1139SIF is quite popular also, but has increased much more in cost over the last 5 years compared to the 5-1/4 inch and requires a larger box.

Dayton Audio just released the MX5-22 and MX6-22 a few months ago to compete with the two Tang Band drivers.
For discussion, as well as a link to a YouTube video comparing the Dayton to Tang Band, go HERE.

 

[Audionaut]

My idea is to make them fully active and wireless, with TWS (so both speakers connect via Bluetooth without needing a cable between them), including amplification and crossover for both drivers.

Any tips or guidance would be really appreciated!

I wouldn't use the RS100 for a two-way project.

If I were you, I’d first consider what the speaker is supposed to do, what needs it’s supposed to meet, where it’ll be placed, and in what kind of room. You probably won’t be very happy with the RS100 in a two-way project, but in a three-way setup, it works very well as a full-range midrange driver.

Amplification and Bluetooth >>>

The simplest and most practical solution for you is something like this. Everything on board

4 x 100W Bluetooth 5.1 DSP Audio Amplifier Board - TSA8814

TSA8814 is a 4x100W Stereo Bluetooth 5 audio amplifier board. It has perfect class-D architecture(Based on TPA3221) and each channel has maximum 100W power output. All channels are capable of outputting nominal power simultaneously and continuously. This board can be powered by any DC12V-30V...

www.tinysineaudio.com

If you want to use individual modules in the enclosure (i.e., 2 separate two-way amplifiers, not everything on a single board like above), Tinysine also offers two-way amplifiers with a TWS Bluetooth module and DSP. Very well-suited for beginners, because you can experiment a lot.

Good luck

 

[Waveform Fidelity]

Hi!
I am a student and I’m currently working on my final degree project and my goal is to design and build a pair of 2-way speakers. Right now I’m trying to choose suitable drivers for the woofer and tweeter.

For the woofer, I’ve been looking at the RS-100, but I’m not completely sure how to pair it with a tweeter, since it seems more like a full-range driver. So I’m a bit confused about how to properly implement a 2-way system with it.

I also wanted to see if anybody had any recommendations for drivers or general advice on going active (separate amplification + active crossover for each way).

My idea is to make them fully active and wireless, with TWS (so both speakers connect via Bluetooth without needing a cable between them), including amplification and crossover for both drivers.

Any tips or guidance would be really appreciated!

Hi Aran

Since your degree is Communications with”sound and image” engineering, I would be tempted to design/study/build something novel. The 2-way, drivers in a box, with a crossover isn’t a particular complex design and if you follow the design process created from commercial software -well there is not a huge amount you can show to your tutor in the way of understanding of wave theory and acoustics.

One suggestion (its just a suggestion) is design and build something novel, but related to “sound and imaging” An omnidirectional speaker using a reflector or lens, or a short phased array of say 4 drivers and show how the beam can be shaped and/or steered to illuminate a listening area. The wave theory is similar to that of antennas, which I am presume you have studied in your Communications Engineering classes.

Just google “Canon S-35 speaker” for a example of a wide “imaging” speaker. With 3D printing you could prototype lens/reflector shapes and demonstrate your understanding of wave theory.

Best wishes with what ever route you take:-;

 

[audio_04]

Hi Aran

Since your degree is Communications with”sound and image” engineering, I would be tempted to design/study/build something novel. The 2-way, drivers in a box, with a crossover isn’t a particular complex design and if you follow the design process created from commercial software -well there is not a huge amount you can show to your tutor in the way of understanding of wave theory and acoustics.

One suggestion (its just a suggestion) is design and build something novel, but related to “sound and imaging” An omnidirectional speaker using a reflector or lens, or a short phased array of say 4 drivers and show how the beam can be shaped and/or steered to illuminate a listening area. The wave theory is similar to that of antennas, which I am presume you have studied in your Communications Engineering classes.

Just google “Canon S-35 speaker” for a example of a wide “imaging” speaker. With 3D printing you could prototype lens/reflector shapes and demonstrate your understanding of wave theory.

Best wishes with what ever route you take:-;

Hi,

Thanks a lot for your suggestion!! I really appreciate it, and I agree that those ideas are very interesting and closely related to wave theory and acoustics.

However, in my case I already submitted my final year project proposal, and I’m kind of committed to developing a pair of active wireless stereo speakers. So at this point I need to stick to that direction.

That said, I’m trying to approach it in a way that still demonstrates solid understanding, not just “drivers in a box.” For example, I plan to focus on aspects like enclosure design, crossover implementation (possibly active/DSP-based), amplification, and overall system integration and optimization.

Thanks again

 

[Timcognito]

@ppataki and @XMechanik have had some interesting and educational endeavors both are great giving and respecting advice. Look at their threads for ideas and push yourself up on the learning curve.

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