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Mini 3-way (7l). f6 ~40Hz. Low distortion in midrange. Recommended PR PIR slopes. Inexpensive drivers and components. (Mechano325)

Maybe for the record, the reason I asked about flush mounting the LF driver was purely aesthetics.

Your designs are so convincing @XMechanik that they often make me play with the thought of trying to build a pair. However I personally don’t like naked drivers. Flush mounting them would make adding grilles a bit easier, that’s all.

Either way terrific work and thank you so much for sharing it all.
 
Just for the curious mind.
What will be the implications to the response, if speaker box orientation is made vertical and speaker drivers are in one line from top to bottom ?
Thanks for sharing.
 
Hiten said:
If change is made in box construction keeping volume same would it give same response/dispersion ?
Ofcourse not asking to make it. Just theoritical question.
Click to expand...
Baffle size/shape determines diffraction calculations and baffle step. Additionally, reorienting the drivers makes the interaction between them different.Thus, there may be enough change to make the design no longer successful. It will need to be modelled again.
 
Yes thats what I wnated to know. Am no expert but probably placing Tweeter and mid range driver offcenter near the edge may help slightly as seen in some vintage 3 way speakers.
regds.
 
As can also be seen in one of his other designs, Mechano323.

Interestingly, it lead to people wondering what would happen if the drivers were arranged KH 310 style. :)
 
JDSP said:
I couldn't find the exact matches for the Inductors but would the following be correct?
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It's hard to tell until the ESR is provided for the replacement coils. They are surprisingly costly, I'd expect something air-core and thick-wired, which is not necessarily. Despite the high costs they would take lot of place and weight. For similar reasons consider bipolar capacitors >10uF (esp. the 270uF, not included on your list).
 
XMechanik said:
It's hard to tell until the ESR is provided for the replacement coils. They are surprisingly costly, I'd expect something air-core and thick-wired, which is not necessarily. Despite the high costs they would take lot of place and weight. For similar reasons consider bipolar capacitors >10uF (esp. the 270uF, not included on your list).
Click to expand...
I've updated the sheet with lower cost components + more information, reduced the price by 35% + added the missing 270uF

There are probably cheaper places to get these in the UK / EU but it's a mission finding all the parts :)
 
Excellent! I was looking for something like this! If you ever make a larger version, lmk :)

I would love to put an efficient larger version of this kind of speaker on a bookshelf and in my hatchback Toyota.
 
Hello, this and your other designs look very interesting. Good performance out of affordable drivers. Win win. I was thinking, Nowadays there are some quite affordable very capable two channel DSP amps available from AliExpress, like the bdm3p module for example. It has got 18 fully parametric eq points and it sounds great. I've bought two already for other speakers and I can fine tune them to a very good result (i was not very happy with their sound before, even with a full passive filter design). For example one module is powering my pair of DIY diyrm sbx3 speaker effortlessly and they have got a 8", 4" and 1" drivers.

Could these speakers or any other of your speakers be built with reduced amount of components in the passive filter and instead use the parametric eq in the dsp amp to tweak the response, but still be single amp channel running each speaker? One good thing with passive filters is the reduced noise from the amp coming to the drivers. (I'm rather sensitive to hiss/noisy amps making their way thru to the speakers, something I often experience in fully bi-amped speakers).

I was looking at ordering components and drivers, and it seemed I had to order from two or three different stores, shipping and complexity adding up and I got a little discouraged. If I could get away with less components and possibly find everything in one or maybe two stores it would be nice indeed (and less expense on passive crossover is also a plus).

Many thanks!
 
Last edited:
Ossian said:
I was looking at ordering components and drivers, and it seemed I had to order from two or three different stores, shipping and complexity adding up and I got a little discouraged.
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Regarding single ordering source, if you are within PE shipping range, you can try the following crossover version. Unfortunately some of the components are currently back ordered (for next month).
m325pe.png
ND28F-6
PC83-4
DSA135-8

9.1ohm
5.6ohm
7ohm

6.8uF
2.2uF
9.1uF
33uF
68uF
250uF

0.15mH
0.44mH
0.6mH
1mH
9mH
4.7mH

$278/pair
 
XMechanik said:
Regarding single ordering source, if you are within PE shipping range, you can try the following crossover version. Unfortunately some of the components are currently back ordered (for next month).
View attachment 443908
ND28F-6
PC83-4
DSA135-8

9.1ohm
5.6ohm
7ohm

6.8uF
2.2uF
9.1uF
33uF
68uF
250uF

0.15mH
0.44mH
0.6mH
1mH
9mH
4.7mH

$278/pair
Click to expand...
Thank you for the effort and taking the time. Unfortunately I'm in Sweden and I put the items in the basket and shipping turned out to be 185 dollars. Too much for me but hopefully it can help someone overseas. By the way, are there details on the port geometry?
 
Ossian said:
By the way, are there details on the port geometry?
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I made the BR tunnel from a piece of HDF glued on slats. The port area corresponds to the area of a 3.5cm diameter tube. That is 1cm x 9.6cm of the tunnel opening, but the slats reduce its width which was taken into account. I thought I had a photo of this piece of HDF with the actual dimensions, but I can't find it. VituixCad->Tools->Enclosure 7l 45Hz gives a tunnel length of about 16cm (enclosure thickness should be subtracted from that). a regular pipe BR tunnel or a suitably cut piece of PP pipe would possibly give just as good a result.
 
Azrael said:
The port resonances are comparatively well under control. Did you do anything special for this or did it just happen that way?
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As this is a three-way system with fp1=650Hz the woofer is already filtered at fundamental port resonance frequency which is f=c/(2*port_length)=1.1kHz. At this frequency range the polyester fiber filling has also some impact on decoupling between the cone and the port.
 
XMechanik said:
View attachment 428629

The drivers:
DSA135-8 link
PC83-4 link
ND28F-6 link

Filter schematics and and charts:
View attachment 428628

THD -47dB or 0.5% (at 86dB)
View attachment 428625

Assembled crossover (3 filters):
View attachment 428624
Component costs: c.a. 280EUR/pair (including drivers)

Box dimensions: 290x174x263mm.
Only the tweeter is flush-mounted.
View attachment 428623

Midrange driver chamber
View attachment 428626 View attachment 428627

BR port and tuning
View attachment 435500View attachment 435499
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Hi there, new here, and very interested in building my set of passive speakers. I have never built a crossover before. What recommendations would you have for videos to watch and articles to read? The carpentry is not a problem.

Regards
Phillipi
 
PRS1623 said:
Hi there, new here, and very interested in building my set of passive speakers. I have never built a crossover before. What recommendations would you have for videos to watch and articles to read? The carpentry is not a problem.

Regards
Phillipi
Click to expand...
Sorry for late reply. The question is what exactly are you having trouble with. As for soldering, you can find many soldering tutorials on YT. As for translating the crossover schematic to component connections, I could probably post the wiring diagram when I have a moment. BTW, it's not that hard, just keep in mind that the component leads connected on the schematic must also be connected on the pad.
 
XMechanik said:
Sorry for late reply. The question is what exactly are you having trouble with. As for soldering, you can find many soldering tutorials on YT. As for translating the crossover schematic to component connections, I could probably post the wiring diagram when I have a moment. BTW, it's not that hard, just keep in mind that the component leads connected on the schematic must also be connected on the pad.
Click to expand...
Hi, thanks for the reply. I guess what I'd need help with is more related to the specs and values of parts; hands-on stuff like soldering is fairly easy for me.

Regards
 
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