3-Way Bluetooth Speaker Build

[DeathMonk]

Long time member, but I've been away for a while. I've built several designs and recently liberated some drivers from a presentation cart/tv /soundbar that was destined for the electronics recycler at work. I thought it would be the perfect opportunity to try learn speaker design.

Some initial investigation looks to be pretty decent drivers:

1x Seas 25TAFNC/QG tweeter
2x Peerless TG9FD Fullrange
2x Seas L15RC/P

I'll be getting the measurement and design tools later this year (after I finish some projects around the house) but in the meantime I would like your thoughts and opinions on enclosure design and baffle layout. Being a speaker designed to move around I need something stable that wont tip easily. I very much appreciate your input!

[JonMarsh]

What room and what placement are you considering? Will this be fed a stereo signal? Have you picked your electronics yet? Downloaded data sheets for these drivers? If I was asked to comment (which you sort of have...) I'd likely suggest that the tweeter is the weak point on this crew, but there's lot of alternatives from Seas, for example, like the 27TBFC, or 27TAC, which a basic HF notch filter can smooth out nicely. But were I in your shoes, I'd give the classic 27TBCD/GB-DXT a close look- the diffraction tweeter is well worth the extra money. In fact, I just bought a pair of those to evaluate for another project...





The directivity control and lower distortion down low are big points for this tweeter. Frankly, you could do a very good two way with these and your Seas Prestige woofers, and save a lot of money on the crossover, though I'd guess with this complement of drivers very low order slopes were probably used, keeping the parts count down (if a passive crossover were used- often it's something done in DSP).




What's more impressive is the directivity and extended polar response off axis:





This is at 0 (black), 15 degrees, 30 degrees, 45 degrees, and 60 degrees. This is much better HF polar extension that you can obtain from a "naked" dome.


I'm thinking off the bat of something a bit sound bar like, with tweeter(s) on the outside, which means two, of course. But this is where understanding your electronics choice comes in, to plan for mono or stereo.

BTW, I have some of the little Peerless full range guys, had been investigating a line array using them from 300Hz on up- may get to that some day, but right now it's a back burner project. They should be very easy to work with.

Last suggestion, probably what I should have lead off with, download a copy of VituixCAD and start getting familiar with it so you'll have a basis for what to do with the measurement data you'll eventually have...


Here's the online Help file if you feel like spending a little time looking it over...


https://kimmosaunisto.net/Software/V...D_help_20.html

[DeathMonk]

What room and what placement are you considering?

The plan is for a portable speaker that can be used anywhere.

Will this be fed a stereo signal?

Mono

Have you picked your electronics yet?

Not yet.

Downloaded data sheets for these drivers?

Yes.

But were I in your shoes, I'd give the classic 27TBCD/GB-DXT a close look

I like the off axis response. It seems like it might be worth it for a speaker where you wont always be at the correct listening position.

I do plan on familiarizing myself with VituixCad. How does it compare to Xsim? I see both used and recommended. As far as baffle layout I was thinking something like this but really don't know the benefits or drawbacks of different layouts.

---M
W T W
---M

[JonMarsh]

From checking it out briefly, X-Sim is a basic passive crossover simulator, created by Liberty Instruments; the last posting on his site shows a file directory for the program and some demonstration files dated 2017; it's reportedly under development (according to message on the web site) but I have a feeling the guy is retired. I've used Praxis and other products from them in the past, but moved on to more useful items. It provides a subset of the capacities of an old program like LspCAD. But it is free, and possibly a faster learning curve for a beginner.

http://www.libinst.com

VituixCAD is used by many professional companies, and for good reason- it's the premier tool out there, and besides the primary simulation/development tool, incudes tools for many common calculations as well as a baffle response calculator, directivity analysis and plotting, etc.

We're talking early elementary school versus college post graduate capabilities.

For individual home users, VituixCAD is free, but I donate monthly to Kimmo- it's worth every penny and then some. Besides passive crossovers it supports a wide variety of active digital tools, and of course you can do active analog crossovers with it, too.

And it's continually evolving and improving- last time I downloaded an update was this weekend. That's a little more recent than 2017.

Just go to the link I provided and start checking it out.

I like the off axis response. It seems like it might be worth it for a speaker where you wont always be at the correct listening position.

Well, for a mono portable speaker, that's likely to be most of the time!

Good luck with your project! And feel free to query folks how they do measurement as well as design. You might get some useful ideas...

[DeathMonk]

Thanks for the replies, Jon.

I downloaded VituixCad last night and was playing around with some Dayton drivers. This is some seriously impressive software - and overwhelming. I have my work cut out for me.

There is a wealth of information out there to get me pretty far into this project but I'm sure I'll have questions.

It might be a while but I will post updates as things progress.