Have you loaded all 4 files I've given you? your sim still shows default impedance and I don't see any "ripple" in your frequency response curves.
Note: Trying to simulate bass response in woofers with accuracy is hard without measured data to truly see what is going on. However I believe your biggest problem is going to be in the ~ 100Hz to 400Hz area as shown. This is because you have baffle step loss (perfectly normal) with a woofer in a bookshelf sized enclosure / baffle.
Note: Trying to simulate bass response in woofers with accuracy is hard without measured data to truly see what is going on. However I believe your biggest problem is going to be in the ~ 100Hz to 400Hz area as shown. This is because you have baffle step loss (perfectly normal) with a woofer in a bookshelf sized enclosure / baffle.
Thank you so much Mr. Dave. Now I can revised my crossover and 700-2000hz now is less bump.
Revise crossover file with help of .FRD .ZMA from Mr. Dave is here
https://file.io/UpIHthg45wSB
Revise crossover file with help of .FRD .ZMA from Mr. Dave is here
https://file.io/UpIHthg45wSB
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Here's my revision of your crossover. All I have done is change parts values. Note: I have had to invert the tweeter polarity to get an inphase response (that is not a mistake):
The following image is with both drivers wired with the same polarity (showing a LR style crossover with a symmetrical reverse null at the XO point):
The following image is with both drivers wired with the same polarity (showing a LR style crossover with a symmetrical reverse null at the XO point):
PS: I have aimed for ~ 85dB sensitivity (allowing for ~5 dB baffle step losses). You may need less compensation if you are planning to place these against a wall or in a book shelf (although I'd advise against it with a rear facing port = boomy)
What Z offset have you used on the woofer? This allows for the acoustic offset since the woofer voice coil is "back" from the baffle, meaning the same frequency played by both tweeter and woofer, the woofer will arrive later.
Here's what I mean about Z offset.
When I model your latest crossover (post #23) - without an offset, I get the same response...
However - when I enter a Z offset for the woofer (~47.5mm = 138usec) - I get the following response for your crossover.
When I model your latest crossover (post #23) - without an offset, I get the same response...
However - when I enter a Z offset for the woofer (~47.5mm = 138usec) - I get the following response for your crossover.
Z in this case is not impedance Z.... this is X/Y/Z in terms of AXIS placement = spatial positioning. X = horizontal offset on the baffle. in this case, both your tweeter and woofer vertically align on the centre of the baffle, so this is 0
The Y is the distance the woofer is from the tweeter. I have already allowed for this in the baffle sim so this should be 0 too.
Next is the Z offset. This would be 0 if you were using a stepped or slanted baffle to make the woofer voice coil align on the baffle with the tweeter.
Because the woofer is "deeper" - its voicecoil is set "behind" the baffle. So we need to enter an acoustic Z offset on the woofer (only - not tweeter) to tell the crossover software how far behind the woofer is in relation to the tweeter.
Now 47.5mm may be too much. I think I only used about 28mm on one of my other designs with a 5" driver. I'll need to check this.
In anycase you need to use some sort of Z offset - 30mm would get you in the ballpark
The Y is the distance the woofer is from the tweeter. I have already allowed for this in the baffle sim so this should be 0 too.
Next is the Z offset. This would be 0 if you were using a stepped or slanted baffle to make the woofer voice coil align on the baffle with the tweeter.
Because the woofer is "deeper" - its voicecoil is set "behind" the baffle. So we need to enter an acoustic Z offset on the woofer (only - not tweeter) to tell the crossover software how far behind the woofer is in relation to the tweeter.
Now 47.5mm may be too much. I think I only used about 28mm on one of my other designs with a 5" driver. I'll need to check this.
In anycase you need to use some sort of Z offset - 30mm would get you in the ballpark
I hadn't guessed you were trying to replicate another design. The design in question uses a stepped baffle to almost bring the woofer voicecoil into alignment. This means either a zero or close to zero value for "Z" on the woofer acoustic offset.
However - your cabinet is flat baffle. this means you will need to enter a Z offset as I suggested (say 30mm) and update your crossover component values, since you are not building the same cabinet.
However - your cabinet is flat baffle. this means you will need to enter a Z offset as I suggested (say 30mm) and update your crossover component values, since you are not building the same cabinet.
Then I will add more 30mm to my woofer to make Z offset to be 0. My bass box pro can not add Z offset.
In case of I add 30 mm MDF thickness to my woofer in front of my Tweeter, What crossover value of LRC I should adjust.
Thank you.
In case of I add 30 mm MDF thickness to my woofer in front of my Tweeter, What crossover value of LRC I should adjust.
Thank you.
I let my carpenter to add 30 mm MDF for the woofer. I think off set now is about 0.59in in Lxim to be adjusted.
The design in question uses a 19mm thick piece. I would recommend you stick with a flat baffle, use a 29mm offset in your design. here is why.
I just measured the dustcap offset of the SB17NBAC. it is 19mm from the basket edge. Then you have an extra 10mm of "flight time" as you are designing and measuring on the tweeter axis. this puts the woofer 29mm "behind" the tweeter.
So stick with a flat baffle, and get the sim working for Woofer Z=29mm. Check your reverse null.
I just measured the dustcap offset of the SB17NBAC. it is 19mm from the basket edge. Then you have an extra 10mm of "flight time" as you are designing and measuring on the tweeter axis. this puts the woofer 29mm "behind" the tweeter.
So stick with a flat baffle, and get the sim working for Woofer Z=29mm. Check your reverse null.
Adding ofset of 29mm (1.14") to woofer parameter, is it "mod delay" in woofer parameter to in put 1.14" am I correct?
add +29mm (1.14") mod delay and revised many parts in crossover get better result. Thank you very much Mr. Dave.
Ok, here's my attempt using the same crossover scheme. Round values to the nearest available for purchase (within 10% should be ok but simulate to check)
This assumes a flat baffle as per your original cabinet drawing and 29mm woofer Z offset (so you can match this in XSim)
Note tweeter is wired in reverse (opposite) polarity to the woofer:
Here is the reverse null:
This assumes a flat baffle as per your original cabinet drawing and 29mm woofer Z offset (so you can match this in XSim)
Note tweeter is wired in reverse (opposite) polarity to the woofer:
Here is the reverse null:
I have gone for a steeper slope on the SB17NBAC to avoid the primary breakup at 9Khz which will result in a 3rd order harmonic distortion peak at 3KHz.
i.e. you want to notch or use a steep slope to reduce the impact of the breakup.
i.e. you want to notch or use a steep slope to reduce the impact of the breakup.
Nice work Dave and quite interesting. Even as TG may not be amused. He seems to be a little sensitive about his builds.
This is a very good example what nonsense you get when you enter wrong data into a good simulation.
I never build a speaker this way, with a fixed x-over topology, trying to replicate a response curve.
Usually, after guessing from provided data I design a cabinet and measure the result. Sometimes I look what other experienced builders did with the selected chassis in compareable builds. This helps saving time as you don't have to follow any option to the last dead end.
Would be very interesting how this "remote control build" measures in different stages. The last improvements by the TS seem a step back to start?
A picture of the x-over and the parts used may give some new ideas.
@ supernut you have to listen for some time with a new tuning of the x-over, especialy if you don't want to measure. The ears adapt to even the worst sounding constructions. So your listening may be quite far "off" by now. Give it a break and then try again with high quality recording material and mixed styles.
This is a very good example what nonsense you get when you enter wrong data into a good simulation.
I never build a speaker this way, with a fixed x-over topology, trying to replicate a response curve.
Usually, after guessing from provided data I design a cabinet and measure the result. Sometimes I look what other experienced builders did with the selected chassis in compareable builds. This helps saving time as you don't have to follow any option to the last dead end.
Would be very interesting how this "remote control build" measures in different stages. The last improvements by the TS seem a step back to start?
A picture of the x-over and the parts used may give some new ideas.
@ supernut you have to listen for some time with a new tuning of the x-over, especialy if you don't want to measure. The ears adapt to even the worst sounding constructions. So your listening may be quite far "off" by now. Give it a break and then try again with high quality recording material and mixed styles.
I had skipped over the "reverse engineer" implications. In anycase, the "new" speaker baffle is not stepped and may be different dimensions? and I sourced the files myself and applied the diffraction and ripple itself. I don't believe the XO topology is copyright (it's 4th order / 3rd order electrical with a shunt resistor to help shape the woofer LP which I have used on prior builds) and a lead tweeter resistor to attenuate, so I can understand someone being upset, but it's not as if I haven't done all the legwork myself off raw self acquired data.