[for the Aussies] Jaycar 2-Way DIY Floorstanding Tower Speakers - aka The 33s

Hey fellow Aussies!

I haven't seen any recent posts here regarding use of the current (June 2019) range of Jaycar speaker components / drivers / woofers / tweeters so I thought I'd see if there was any interest out there still for people wanting to DIY build some speakers using this 'response' range of products?

I started an idea and build 2.5 years ago and after many changes (with large gaps in between) I finally have a recipe for a speaker I'm proud of and does what I intended it to do!

Short version: ~50L ported enclosure using Jaycar CT2007 1" Tweeter and Jaycar CW2194 6.5" Woofer, tuned to F3 of 33Hz. Designed for enjoying both Movies AND Music without the requirement of a subwoofer.

YES, I do have a sub and love my bass but I also have a 2.5 yr old toddler so I still wanted speakers I could enjoy while he sleeps. These speakers walk the line between not enough and too much low end so you can use them as-is and still enjoy but the sub is always there if need be. Are they reference monitor flat response? No, and they were never meant to be. Are they fun and enjoyable to use for movies and music? Absolutely! :)





I haven't arranged anything yet (I can if need) but I thought I'd gauge some interest if there was anyone out there looking to build something like this and if they were keen on some plans/designs so they'd have the info they need to build their own?

If you've built something similar then please share as I'd love to see your creations from also using the Jaycar drivers :)
 
Zorz, cheers mate :)

Moondog55, surely the house can wait a little longer right? You need something to listen to while you work on the renos :p

Also, I've finally completed these by stealing some pre-made grilles from some old dicksmith (DSE) tower speakers, shown above with silver drivers, and nerve-rackingly drilling holes and installing cups to mount them. Photo isn't too great but they came up looking a treat! Almost can't tell they were DIY now :)


 
D1GGY, avtech23, let me know if you need more to get started :)

BASIC SPECS: (mostly Jaycar parts)

50L enclosure with single 58x120mm bass port, CX2688
Crossover: Tweeter 2nd order with l-pad 'REVERSE POLARITY', woofer 1st order
CT2007 (tweeter)
CW2194 (woofer)
Capacitors, 15uF 100V Electrolytic Crossover Capacitor
Resistors, all 10 watt wirewound
Inductors (not from Jaycar), 0.39mH 21AWG and 3.0mH 20AWG

The l-pad looks weird because I actually had these speakers working with a different tweeter for quite some time after originally failing to get the Jaycar tweeters working how I wanted. Unfortunately the other tweeter went EOL so to be able to quickly and easily change between tweeters I made it so I could alligator clip resistors on the l-pad in parallel to get the desired result without re-soldering the crossover. Makes for quick changeover.

 
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Hi Robert,

I know it's an old thread but I just found it while looking for other things here.

Just a few comments:
- that resistor R6 - is that the DCR of the coil?
- if so replace the coil with a lower DCR one, like a cored one
- with this one you are losing approx. 1.5 dB of sensitivity
your woofer is 87 dB, less 1.5 = 85.5 dB, and that is before any BSC

- which brings the next suggestion - implement some BSC
- looking at your boxes their width is maybe 22 - 24 cm
- using this formula: 115 / 0.24 = 479 Hz
479 x 0.707 = 338 Hz, this is your BSC frequency
- put a parallel LR after your coil - L ~0.8 - 1.0 mH, R ~ 2 - 3 ohm
This will bring your woofer's level to roughly 84 dB.
So you'll have to reduce the tweeter's level accordingly.

That woofer also has a very peaky top end so put a Zobel across its terminal, it will tame it a bit and also flatten the impedance.

Finally the values in the tweeter section look a bit strange, as if you are cutting it at around 1.5 kHz. That will stress the tweeter badly.

Of course you may not read all this, but I thought it was worth pointing out.

Cheers
Stan
 
Hey guys, I've just been given these exact speakers but in 19L sealed boxes as unfinished projects, just needing crossovers. Easy I thought. Heh. I had no idea I knew so little. Any way hate to be asking but and it's only because I cant give this the time that is really needed I gotta concede to this one and ask for help. I've tried some of the online calculators but I could be miles out and have no idea. I just need a parts list and diagram and I can do the rest. Roughly the same requirements as above but sealed enclosures obviously, then I want to give them back to my mate who stopped the project due to bad health and thought he'd never see them finished so gave them away. Any help would be greatly appreciated, cheers.

PS ....old thread and all that etc...roll the dice...
 
An online calculator will almost certainly give you a poor result, but other than that (not very helpful) suggestion, I'm not sure what you can do: the original project has a crossover with parts values, you could try that. I could have a look at the project in Xsim, but that wouldn't use measured data as I don't have the drivers and have never used them. Jaycar's web page has FR plots for them, but they may not be accurate.


Sorry I can't be more helpful.



Geoff
 
Yeah when I found this thread I thought it was finally what I'd been looking for but then I read stanislav's comment, understood only about five of the words he used and realised yet again how little I know and understand. The first bit I thought I could use but then he mentions about cutting the tweeter at 1.5khz will stress it so if I change that it changes a bunch of stuff and I'm back at square one. And how does he know that woofer has a peaky top end? Any way, I guess what I need to know is would this setup be correct for me.? Crossover type, l pad etc? What should I cut the tweeter at? Then I recalculate the crossover components? Then apply stans suggestions? Then my brain explodes.
Can you help with a diagram of all that? It will feel like a minor miracle if I can pull this off. As an average guy, with average ears, will I notice the difference between a generic crossover vs custom? I mean they're cheap *** speakers anyway right? It'd just be nice if they don't sound terrible.
 
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There are a number of factors that make it difficult to say what's right or wrong. I used to run domes that low all the time, because it helps sorting the power response. I bought D25AG when Jaycar first brought them out. If I felt they were stressed I would either cross them harder, or higher until they were useable.

Then people started measuring THD on tweeters, then it was found that THD is potentially not as audible as power response variations.
 
The best I could get from the Jaycar supplied responses was not that good, the woofer is really quite ragged and needs a large (3mH) inductor to squish the rising mid range. A good cabinet design might help the bass response and enable a smaller (and cheaper) inductor to be used.

I worked out a XO point of about 1800Hz. The tweeter is also a bit ragged and the exercise is made difficult because the ZMA (impedance) graph for the tweeter isn't supplied.

The sim indicates a low efficiency of about 82dB. And I haven't looked at the cabinet yet, that will need someone who can work those details out from the woofer specs.

For what it's worth, the tweeter looks like this: 8.2 mF series cap, 2mH shunt coil and a 10 ohm series/8 ohm parallel resistors L-pad. Woofer is 3mH inductor (iron core for low price), and a 5.1mF cap, and 2.7 ohm resistor as a sort of 'Zobel' filter to make for a smoother response and impedance curve.

No idea whether this would work but it should sound better than an off the shelf part.


Geoff
 
Sorry I've not been active guys, didn't think this would get any traction but thank you for your inputs!

The main issue, DATA! Specifically, lack of it! I love Jaycar but garbage in = garbage out. Without proper info (and without proper measurements) I couldn't theoretically design something well enough that could then be fine tuned (at least by me). I plotted responses from picture graphs to actual data files where I could but it was still not great.

So, this might not make some people happy, BUT sadly I removed the Jaycar tweeters (just bugged me long term and couldn't get them where I wanted) , instead I fitted some C3005A - https://core-electronics.com.au/25mm-1-50w-shielded-tweeter-speaker.html
These also were not amazing for info but lower Fs I thought I had a chance to get them to work in a 2-way. Ran these for a bit in my 2-way setup and they were ~$60pr for me so only $10 more than a pair of Jaycar tweeters at the time.

To fix the bass (my idea for BSC) I moved to a TMM design and chucked in an extra woofer, running in parallel with the original.

Shorter bass port gave stronger bass response with 40mm length (in my room / environment at least) with removal of port entirely (just the 19mm thick wood hole) making them sound like a subwoofer in P-plater car days (beefy at a particular note but not great across a range).

Have a look at xsim snapshot, I messed around with components quite a bit to be honest, I don't know if this theoretical response graph is even close to what I'm actually getting but at least they sound the best they ever have while I've been using them!
Using them for music every other day and a movie up nice and loud every week or two and they're still going strong.

Well, might be more questions than answers here, but hopefully it's useful for someone in the future to get what they have working, or move towards a design using drivers with proper data (Dayton comes to mind). For what it's worth, I built some book shelf 2-ways using drivers that had all the accurate data you could want, and I'm still listening to them on my first crossover revision, not 7th revision..... and they do exactly what they were designed to! Good = good chances for result!

If someone sticks with the jaycar lineup, and gets them to a desirable point with affordable X-OVERs then please share for the other folks here, thank you :)

(yes, those resistors are connected with alligator clips, I was 'seasoning to taste' and heck of a lot easier than soldering each time haha)
 

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I'd like to build a speaker one day using the CT2007, to make a point I guess. I'd probably print a waveguide for it. I'd choose a woofer to suit it and make good use of EQ. With the right cabinet and crossing there's no reason it shouldn't sound good.

There are a few things I'd suggest about your sim but first, Xsim doesn't show phase separately unless you set it that way. Until then at least you won't have any need to see the blue phase trace you see now, just red and yellow.