Garage speakers Low cost important

[Moondog55]

Another project for a friend, I'm reusing a freebie box of 30 litres and I have a good enough 5 inch midrange here salvaged from an old Sony 2-way.
In my bits box I have a 5.8mH coil and a 47uF cap which should give me close to a Bessel roll-off on the low end at ~300Hz The mid should be OK using its natural roll-off but I can find a coil for a first order cut at if I need it
mid will be used in a closed box ( Actually my coffee can trick ) of 1.75 litres

My problem is not having another coil to use on the woofer ( which hasn't been found yet but I have a few cheap 8inch here and 8 is the biggest the box will take
What I do have in my box is a large selection of large caps
Has any-one tried using a shunt coil in a first order XO in combination with a normal ( parallel ) second order high pass

 

[AllenB]

If you mean that one of the drivers will have a second order high pass filter followed by a shunt coil to cut the highs, you should consider that there will be relatively little source impedance above the passband for the shunt coil to work with and it's probably not a good idea unless given some careful consideration.

 

[sreten]

Hi,

Can't make much sense of your post.
You can't use shunt components in a parallel 1st order crossover.

Try using the coil and cap 1st order series on both drivers.

rgds, sreten.

 

[cT equals piD]

Do you mean something like a hybrid series/ parallel crossover network? What I'm thinking is,

-the low-pass (LP) coil connected across the input terminals to the second order high-pass filter,
-the tweeter connected to the output terminals of the high-pass filter (of course)
-the + terminal of the woofer connected to one terminal of the LP coil
-the - terminal of the woofer connected to - out of the amp
-finally, the other terminal of the LP coil connected to the + out of the amp.

IMO that would work in some fashion. I haven't tried it.

Regards,
Pete

 

[sreten]

Hi,

A series second order on the mid and first order on the bass
has one inductor and two capacitors, you could try that.

rgds, sreten.

No such thing as a hybrid series/parallel crossover.

 

[PeteMcK]

something like this?

 

[cT equals piD]

In my post #4, substitute mid for tweeter. Actually what I had in mind wouldn't work at all. In the pass-band for the mid, the impedance of network including the mid approaches being equal to the impedance of the mid itself. So in that range, the woofer would be receiving about half of the amp's voltage, assuming equal impedance of the woofer and mid.

-Pete

 

[cT equals piD]

something like this?

Can you explain your network? I see high-pass and maybe band-pass sections, but not a low-pass section.
Pete

 

[PeteMcK]

series, 1st order on woofer, 2nd on mid, tweeter is 1st order in parallel with the mid,
add a couple of resistors to taste...

 

[cT equals piD]

series, 1st order on woofer, 2nd on mid, tweeter is 1st order in parallel with the mid,
add a couple of resistors to taste...

Thanks, I understand it now. With schematics, I'm used to seeing wire junctions shown with a dot.

-Pete

 

[Moondog55]

OK What I was thinking won't work.
I get used to being wrong.
Problem solved though as I just found an 8inch full range with a rising response so I guess it's going to be a 1.5Way Baffle is 270mm wide so I guess I'll just add a boost woofer 1st order at ~ the -6dB point somewhere close to 400hz. 2.7 - 3mh should do it
I did say low cost was the priority