For private reasons I have to finish my DIY speaker ASAP, I have two Hivi M6N and 1 MOREL MDT32ST in one 41liter bass reflex box. I want to build a temporary x-over without measuring and later when I have time to make the measurements and desing (and learn) a proper xo. Could you please advise a schematic which would the best in this case?
I would cross @1500Hz is it enough?
M6N:
Morel:
Thanks
I would cross @1500Hz is it enough?
M6N:
Morel:
Thanks
Crossing over at 1500Hz would be difficult to do without detailed measurements...I worry about keeping enough low frequencies out of the tweeter.
I have made a xo desing with the manufacturer parameters in XSIM. What I dont like is the 5dB jump between 1k and 4k. Can I handle this problem somehow? Is this schematic ok? thanks
An externally hosted image should be here but it was not working when we last tested it.
It would work....as in it'll make sound. You'll need a notch filter in series with the woofer...if you use a filter in parallel with the woofer the impedance will likely drop too low.
The bigger issue is that the frequency response of the woofers and tweeters on the test baffle are not the same as the frequency response in the actual speaker...so that peak may or may not be there, and if it is there may or may not be that shape. If it isn't there, there may or may not be peaks in other locations.
Scott
Ing, despite SpeakerScott's worthy efforts to do something with those HiVi M6N woofers, they just look plain awful in this application.
Something like an 8" SEAS CA22RNY just looks so simple by comparison in a 40L box. Crossover around 2.5-3.5 kHz.
Time to reconsider? 🙂
Something like an 8" SEAS CA22RNY just looks so simple by comparison in a 40L box. Crossover around 2.5-3.5 kHz.
Time to reconsider? 🙂
Well, it is too late🙂 This my first DIY speaker since a while, and I wanted to start with some cheaper speakers, and I have get this speakers quite cheap. MY plan is to built some really good one after this. I mean that is in my 10 years plan 😀 Thanks anyway🙂
Thanks for the help. Yeah I am aware the test baffle is not the same, but unfortunatelly I have this paramteres so far. So I need to make something with this. I will check the notch filter.
Everybody seems to have scattered on this one. But since you have built some nice cabs already, I'll tell you what I know.
http://www.diyaudio.com/forums/multi-way/272036-hivi-morel-2-way-stand-speaker-project.html
I had a play with a fourth order 1.7kHz crossover and it was doing the right things, but it's quite a modelling job really. I was using much bigger coils than you, BTW. Bafflestep an' all that.
Seems to me the HIVi M6A is just the M6N's similar predecessor. 😎
So we could work with Paul Carmody's tested HiVi M6A ZX Spectrum design.
https://sites.google.com/site/undefinition/zx-spectrum
That's an idea for the bass and treble filters. Obviously the Morel will need something slightly different. I never really like Paul's deep tank notches, and a 22R resistor might play nicely in series with that 0.1uF capacitor. The rest, as they say is just technique. For doubled basses in series or parallel, you do that halving and doubling thing on bass filter values, and adjust tweeter level accordingly. 🙂
http://www.diyaudio.com/forums/multi-way/272036-hivi-morel-2-way-stand-speaker-project.html
I had a play with a fourth order 1.7kHz crossover and it was doing the right things, but it's quite a modelling job really. I was using much bigger coils than you, BTW. Bafflestep an' all that.
Seems to me the HIVi M6A is just the M6N's similar predecessor. 😎
So we could work with Paul Carmody's tested HiVi M6A ZX Spectrum design.
https://sites.google.com/site/undefinition/zx-spectrum
That's an idea for the bass and treble filters. Obviously the Morel will need something slightly different. I never really like Paul's deep tank notches, and a 22R resistor might play nicely in series with that 0.1uF capacitor. The rest, as they say is just technique. For doubled basses in series or parallel, you do that halving and doubling thing on bass filter values, and adjust tweeter level accordingly. 🙂
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I did a little playing and I don't think it is that bad to deal with. Note Ing you should do your own modeling as I may have made a mistake, as I did it pretty quickly.
What I did was trace the HiVi curve, add baffle step (using your cabinet dimentions (but only one driver) using response modeler spreadsheet. I then spliced in low frequency data based on your cab and tuning using response blender spreadsheet.
I took that and loaded into speaker workshop, set a goal of 4th order accoustic bessel at 2Khz and the below is what came out.
Note that the rise between 50 and 200Hz (over the original response) looks sus to me. but I think it shows that the drivers can be massaged into shape.
note I increased the spl 6db and halved the impedance (to simulate the two drivers) rather than using two drivers as the speakerworkshop optimizer doen't work with more than a single driver. Note I didn't spend much time trying to tweak this so it can almost certainly be improved 😉
Tony.
What I did was trace the HiVi curve, add baffle step (using your cabinet dimentions (but only one driver) using response modeler spreadsheet. I then spliced in low frequency data based on your cab and tuning using response blender spreadsheet.
I took that and loaded into speaker workshop, set a goal of 4th order accoustic bessel at 2Khz and the below is what came out.
Note that the rise between 50 and 200Hz (over the original response) looks sus to me. but I think it shows that the drivers can be massaged into shape.
note I increased the spl 6db and halved the impedance (to simulate the two drivers) rather than using two drivers as the speakerworkshop optimizer doen't work with more than a single driver. Note I didn't spend much time trying to tweak this so it can almost certainly be improved 😉
Tony.
Attachments
Hi Ing here is a link software I used both the response modeler and the FRD blender spreadsheets there to get an approximation of how the driver would perform in your enclosure, rather than just relying on the IEC baffle measurements.
Also check out the tutorial by Dave Dal Farra at the end of the page 🙂
Tony.
Also check out the tutorial by Dave Dal Farra at the end of the page 🙂
Tony.
Hi Tony,
Dal Farra's tutorial is useful, although it lacks the explanation how one
(a newbie) can perform a subtraction of the IEC baffle response to get
an infinite baffle response. It's either that or I have missed the information
about it.The IEC baffle dimensions are provided, not for the roundover though,
assuming there is one at all.
Lojzec, it is a bit of a problem. Not all factory measurements are done in the same way. Some are infinite baffle, some are IEC baffle, and some are quite possibly something else (I think seas are a case in point). A lot don't even mention what the measurement conditions are.
I haven't worried about it (I think originally when I read the tut I didn't understand it and skipped that bit!) But from memory the response modeler spreadsheet allows you to do the BS correction as either addition or subtraction, so I guess the way to go is to add in the IEC BS, save then reload and model with your actual baffle.
I've just applied the BS correction as if it was infinite baffle and spliced in the low frequency from the sim (in the 200-300 hz range) The HiVi measurement doesn't state the measurement conditions but it is likely IB.
I was actually thinking this afternoon I should do the procedure on my SB 4" drivers and see how it compares to my actual measurements, I'll check if the are IEC (I think they are) and see if I can work out how to do the subtraction bit.
Tony.
I haven't worried about it (I think originally when I read the tut I didn't understand it and skipped that bit!) But from memory the response modeler spreadsheet allows you to do the BS correction as either addition or subtraction, so I guess the way to go is to add in the IEC BS, save then reload and model with your actual baffle.
I've just applied the BS correction as if it was infinite baffle and spliced in the low frequency from the sim (in the 200-300 hz range) The HiVi measurement doesn't state the measurement conditions but it is likely IB.
I was actually thinking this afternoon I should do the procedure on my SB 4" drivers and see how it compares to my actual measurements, I'll check if the are IEC (I think they are) and see if I can work out how to do the subtraction bit.
Tony.
Thanks Tony. I do know of a way how to subtract the baffle response,
it's just that I would like it to be covered in the tutorial especially because
the author thought of it to be a worthwhile effort, otherwise he wouldnt
have mentioned it.
it's just that I would like it to be covered in the tutorial especially because
the author thought of it to be a worthwhile effort, otherwise he wouldnt
have mentioned it.
I've just been playing around with it. But I'm not 100% convinced it works as it should. I traced SB12MNRX25-4 spl curve (because I have one) and set up an IEC baffle in the response modeler spreadsheet. (setting the distance as it is specified on the SB datasheet).
The thing that doesn't seem right is that when modeled as a gain it simply increases the SPL rather than decreasing it. The actual baffle diffraction data is not inverted (as I would have expected)..
I applied it as a gain and then loaded the new version into speaker workshop to compare to the original. There is not much difference, but I think the change is incorrect.
Below a screen shot of the SW comparison, and how I set IEC baffle in the response moddeler spreadsheet. The blue curve is the adjusted one. It seems it has just added the diffraction curve to it, not subtracted it.
I suspect that when modeling low frequency with a box modeling program and splicing it at 300Hz or so that the effects of the IEC baffle could probably mostly be ignored.
Tony.
The thing that doesn't seem right is that when modeled as a gain it simply increases the SPL rather than decreasing it. The actual baffle diffraction data is not inverted (as I would have expected)..
I applied it as a gain and then loaded the new version into speaker workshop to compare to the original. There is not much difference, but I think the change is incorrect.
Below a screen shot of the SW comparison, and how I set IEC baffle in the response moddeler spreadsheet. The blue curve is the adjusted one. It seems it has just added the diffraction curve to it, not subtracted it.
I suspect that when modeling low frequency with a box modeling program and splicing it at 300Hz or so that the effects of the IEC baffle could probably mostly be ignored.
Tony.
Attachments
A how to subtract a baffle step from a response
In order to subtract the baffle step response from the response
that already includes baffle step, you gotta have those two frd's
saved separately. First you model the baffle step as a loss, then
save it and calculate its minimum phase. Then you prepare the
other frd of the driver with baffle step already calculated in, with
the minimum phase. Load these two to a software that can perform
a division of these frd's. In the numerator you put the response of
the driver with its baffle step and in the denominator only the baffle
step frd. HolmImpulse has such a mathematical function C=A/B.
In order to subtract the baffle step response from the response
that already includes baffle step, you gotta have those two frd's
saved separately. First you model the baffle step as a loss, then
save it and calculate its minimum phase. Then you prepare the
other frd of the driver with baffle step already calculated in, with
the minimum phase. Load these two to a software that can perform
a division of these frd's. In the numerator you put the response of
the driver with its baffle step and in the denominator only the baffle
step frd. HolmImpulse has such a mathematical function C=A/B.
Thanks Lojzek, I actually tried that in holm impulse last night (using the C=A/B) but I wasn't sure I was doing it right. I used the baffle response modeled as a gain rather than as a loss 🙂 I'll try again with the gain modeled as a loss.
This is quite timely as I am working on my own tutorial, and I was just getting to the Baffle step simulation bit 🙂
Tony.
This is quite timely as I am working on my own tutorial, and I was just getting to the Baffle step simulation bit 🙂
Tony.
Just for completeness here are the measurements in holm impulse. Ing you do not need to worry about this for your factory measurements of the HiVi as I do not believe (looking at it's response curve) that it was measured on an IEC baffle.
It is possible to do this if you want the best accuracy but if splicing in simulated low frequency response below 300Hz it looks like it will make little difference.
Tony.
It is possible to do this if you want the best accuracy but if splicing in simulated low frequency response below 300Hz it looks like it will make little difference.
Tony.
Attachments
Here is a comparison of the simulated result (using traced manufacturers curve and blended in simulated low end response) compared to an actual outside measurement of the finished speaker (which is 1/6th ocatave smoothed). Blue trace is the real measurement.
I would say that the correlation is pretty good. The nastiness in the low frequencies in the real measurement is due to reflections.
Sorry for the OT Ing, I hope it was at least informative 🙂
Tony.
I would say that the correlation is pretty good. The nastiness in the low frequencies in the real measurement is due to reflections.
Sorry for the OT Ing, I hope it was at least informative 🙂
Tony.
Attachments
Since we are interested in having the response simulated in free space,
our baffle step model should be adjusted as a loss. Otherwise the
difference between loss and gain is strictly 6 db in spl with the same
response shape. Adding the baffle step equals to multiplying the two
responses.
So great you are working on a tutorial!
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