I will try this first
maybe I will increase (not too much ) those resistor to suit the woofer power
the mid 8 ohm and the tweeter is 8 ohm
I am assuming the mid and tweeter are somthing like 91db -93db sensitivity
can you jReave do a chart to whole ebay XO . and to see what influence has those resistor to total FR ?
An externally hosted image should be here but it was not working when we last tested it.
maybe I will increase (not too much ) those resistor to suit the woofer power
the mid 8 ohm and the tweeter is 8 ohm
I am assuming the mid and tweeter are somthing like 91db -93db sensitivity
can you jReave do a chart to whole ebay XO . and to see what influence has those resistor to total FR ?
I think that's a good starting point but the step after that (playing with the resistors on the ebay xo) is not what I've suggested. But try it if you want to. It's not going to hurt anything.
You see, you are not quite getting what I'm trying to tell you here. To model a driver, you need to have the frequency response, the impedance response (the whole impedance response for the full frequency range which will be different for pretty much every single 8ohm driver), the baffle dimensions and driver positions on the baffle and the T/S parameters of woofers and mids.
You need those 1st three in particular to model what a particular xo is going to do for particular drivers in a particular speaker and we don't have all of those for your mid and tweeter. So sorry, I can only model the woofer accurately. You have to go with trial and error for the rest.
You see, you are not quite getting what I'm trying to tell you here. To model a driver, you need to have the frequency response, the impedance response (the whole impedance response for the full frequency range which will be different for pretty much every single 8ohm driver), the baffle dimensions and driver positions on the baffle and the T/S parameters of woofers and mids.
You need those 1st three in particular to model what a particular xo is going to do for particular drivers in a particular speaker and we don't have all of those for your mid and tweeter. So sorry, I can only model the woofer accurately. You have to go with trial and error for the rest.
the ebay XO arrive a few days ago .
I wanted to try it first . I did this mod in the picture .
I have to say the High's and the Mid's sound now much more accurate .
I think there is improvement in the bass .overall I am satisfied may be I will change the resistor in the HPF and Band pass filter
I wanted to try it first . I did this mod in the picture .
I have to say the High's and the Mid's sound now much more accurate .
I think there is improvement in the bass .overall I am satisfied may be I will change the resistor in the HPF and Band pass filter
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Ok, I had to go and re-read a few pages to remember what your situation was all about. With the woofer inductor now up to 4.6mH, you should have a lot more bass as long as the mid and tweeter levels are not too high.
I suggest listening to the speakers as you have them right now with music that you are very familiar with for at least a few days so that you can determine if the driver balance is the way you like it.
Is the bass loud enough?
Are the symbols too prominent?
Are vocals too shouty?
etc, etc....
And then make an adjustment to either the tweeter or mid resistors as you think is necessary. And if you think it sounds good to you, then it does. No need to change to the design that I suggested.
Cheers
I suggest listening to the speakers as you have them right now with music that you are very familiar with for at least a few days so that you can determine if the driver balance is the way you like it.
Is the bass loud enough?
Are the symbols too prominent?
Are vocals too shouty?
etc, etc....
And then make an adjustment to either the tweeter or mid resistors as you think is necessary. And if you think it sounds good to you, then it does. No need to change to the design that I suggested.
Cheers
after a couple of weeks with this XO
the high's and Mid's are very good and accurate
The bass on most song is good and tight but on some song the bass is not accurate and muddy . maybe is because the lift on 350HZ ?
jReave I would like to stay with this eaby XO . what mod do you suggest me to do to get flat and accurae bass response ?
the high's and Mid's are very good and accurate
The bass on most song is good and tight but on some song the bass is not accurate and muddy . maybe is because the lift on 350HZ ?
jReave I would like to stay with this eaby XO . what mod do you suggest me to do to get flat and accurae bass response ?
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It's a little hard to know exactly what the problem is by your description. Maybe it's the FR. Maybe it's a driver quality issue. Maybe it's even a cabinet resonance issue.
I guess the 1st thing to do is to try to better define the nature of the problem. So find those songs and/or places in songs where things don't sound good. That can maybe help us to identify the problem frequencies. You could also run some simple test tones and try to subjectively determine if there is anything that stands out as too loud or too resonant/distorted if you feel ambitious. WinISD has some tones that you can use.
Here's what I would be double checking:
Are you sure it's the woofer? --> Disconnect the mid and tweeter. Is the problem still there?
Are you sure it's not a cabinet resonance? --> Try the woofer alone again but now unattached to the box. Still sounds bad?
Or if you want, you can take care of the woofer the way I originally suggested by just adding a few more caps and resistors to the woofer filter and see how that sounds.
The values are a little different than before because this time I'm not trying to use values that you already had. The schematic and FR are below. If you want you can try C4 = 40uF to 50uF. The differences are pretty small.
For comparison, the last chart is the woofer response with your current xo.
I guess the 1st thing to do is to try to better define the nature of the problem. So find those songs and/or places in songs where things don't sound good. That can maybe help us to identify the problem frequencies. You could also run some simple test tones and try to subjectively determine if there is anything that stands out as too loud or too resonant/distorted if you feel ambitious. WinISD has some tones that you can use.
Here's what I would be double checking:
Are you sure it's the woofer? --> Disconnect the mid and tweeter. Is the problem still there?
Are you sure it's not a cabinet resonance? --> Try the woofer alone again but now unattached to the box. Still sounds bad?
Or if you want, you can take care of the woofer the way I originally suggested by just adding a few more caps and resistors to the woofer filter and see how that sounds.
The values are a little different than before because this time I'm not trying to use values that you already had. The schematic and FR are below. If you want you can try C4 = 40uF to 50uF. The differences are pretty small.
For comparison, the last chart is the woofer response with your current xo.
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Hi jReave thank you very much for your assistance
the problem is definitely was from the woofer
its about the low's production and not some noise or something like that .
I did a mod to the XO . now the XO is like the picture below
there is now a big improvement , it is way better than combaining the two inductors .
Its look fine for now you have an idea how to improve this eaby XO LPF ?
the mod you suggested to do it too complicate and I would like to stay with the eaby XO bacause its has better high's and mid's
the problem is definitely was from the woofer
its about the low's production and not some noise or something like that .
I did a mod to the XO . now the XO is like the picture below
there is now a big improvement , it is way better than combaining the two inductors .
Its look fine for now you have an idea how to improve this eaby XO LPF ?
the mod you suggested to do it too complicate and I would like to stay with the eaby XO bacause its has better high's and mid's
Attachments
Well, that certainly surprised me.
Given that your initial problem was a lack of bass, I assumed that you weren't compensating enough for baffle step loss. But with a fairly wide baffle with a 12" driver, I didn't figure you needed the whole 6dB so I've been modelling at 4dB of baffle step loss. And the most common way to compensate for that is to use a bigger inductor on the woofer which is what we did.
But you thought that sounded muddy sometimes - which I'm going to translate as too much LF below about 300Hz (see attached) - and which you seem to have confirmed by finding the sound to be better by reducing the inductor from 4.63 to 2.83mH. Which means that 4dB of baffle step compensation (bsc) was too much. In fact, way too much. Because the only way that a 2.83mH inductor produces a flat LF response (assuming Dayton's measured FR is accurate) is if I don't use any bsc on it at all. That's the 1st chart below with 2.83mH (.8ohm) and the 31uF cap which is showing a flat response and which is what you have on it now. So that's what it looks like in other words if I don't include any bsc which means that you must be getting a fair bit of boundary reenforcement in the LF from the way you have your speakers placed in your room.
The 2nd chart shows you the FR from before, with the 4.8mH combination and 31uF cap and here you are getting a peaking LF response which would account for the muddiness.
The last chart shows you the response with the 2.83mH inductor but with the parallel cap now increased to 50uF. You can see that this does a little better job of pulling the response down above about 600Hz. At this point, that's about the only suggestion I have for you other than perhaps tweeking the mid and/or tweeter levels again to match the new woofer response.
Best of luck
Given that your initial problem was a lack of bass, I assumed that you weren't compensating enough for baffle step loss. But with a fairly wide baffle with a 12" driver, I didn't figure you needed the whole 6dB so I've been modelling at 4dB of baffle step loss. And the most common way to compensate for that is to use a bigger inductor on the woofer which is what we did.
But you thought that sounded muddy sometimes - which I'm going to translate as too much LF below about 300Hz (see attached) - and which you seem to have confirmed by finding the sound to be better by reducing the inductor from 4.63 to 2.83mH. Which means that 4dB of baffle step compensation (bsc) was too much. In fact, way too much. Because the only way that a 2.83mH inductor produces a flat LF response (assuming Dayton's measured FR is accurate) is if I don't use any bsc on it at all. That's the 1st chart below with 2.83mH (.8ohm) and the 31uF cap which is showing a flat response and which is what you have on it now. So that's what it looks like in other words if I don't include any bsc which means that you must be getting a fair bit of boundary reenforcement in the LF from the way you have your speakers placed in your room.
The 2nd chart shows you the FR from before, with the 4.8mH combination and 31uF cap and here you are getting a peaking LF response which would account for the muddiness.
The last chart shows you the response with the 2.83mH inductor but with the parallel cap now increased to 50uF. You can see that this does a little better job of pulling the response down above about 600Hz. At this point, that's about the only suggestion I have for you other than perhaps tweeking the mid and/or tweeter levels again to match the new woofer response.
Best of luck
Attachments
I am very appreciate your help guys and I am sorry I did not under stand you well
I am looking for a cheap solution , i can buy capacitors and resistors with no problem , but inductors i can buy only two for LPF and no more .
if you have an idea how to do it with this budget I will be glad
I saw in ebay this crossover do you think it will be good ?
2pcs New for Kasun as 33c 3 Way 3 Unit Hi Fi Speaker Frequency Divider Crossover | eBay
I brought 2 of these xovers as well and found the lack of bass was a big problem after taking resistors out lowing them increasing them adding different chokes I relied it wasn't going to work out adding new ones so I pulled them apart read the inductors with my DMM Inductions meter to find they didn't match schematics all that well, so with adding chokes together and unwinding a few chokes to get the design chokes I came up with this xover which to my ears sounds really good. For the money I spent on these brought xovers was cheap and I got to build new from them
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