Hi
Let's say we have a woofer that is good to xo anywhere up to 500hz and a mid that is good to xo down to 200hz.
If an XO anywhere within that range 200-500hz is just as good for both drivers where should it be? Lower or higher?
BTW, the baffle step -3db point will be around 400hz.
Mos
Let's say we have a woofer that is good to xo anywhere up to 500hz and a mid that is good to xo down to 200hz.
If an XO anywhere within that range 200-500hz is just as good for both drivers where should it be? Lower or higher?
BTW, the baffle step -3db point will be around 400hz.
Mos
Id say try all in between which provides the least phase cancellation. The lower the x over freq, the better the dispersion would be from the , but the lower the ultimate power handling.
Rod Elliot recommends crossing outside of the intelligence band, 300-3kHz. 300Hz sounds like it would work well here without overly taxing your drivers.
Out of band response
You may want to consider the how smooth the response of the drivers is outside the band in which they're being used when deciding the xover point too
Pete McK
You may want to consider the how smooth the response of the drivers is outside the band in which they're being used when deciding the xover point too
Pete McK
You need to consider driver diameters/dispersion, driver bandwidths, and their physical location. Without specifying all those things, trying to choose a crossover doesn't even rise to the level of theoretical exercise.
And what does this "just as good" mean, exactly??? Good when individually crossed?
As for the baffle step, I really don't know about this, but I think some people will cross the mid at 400Hz, which is a non-sense to me. IMO there are factors that you haven't specified and are more important than just a baffle step to affect the design of the crossover (and haven't you already decided to use a 3-way?) And if any x-over point would just as good, you surely wouldn't have had asked the question. But as an "audiophile", I will seriously consider the one that bring a maximum transient (is it 200 or 500? 😉). But then again, aren't they just as good? 😕
But, SY, by having specified the 400Hz baffle step, haven't those aspects been taken into consideration already? Or may be not? Well, looking from the whole question, the 400Hz must have been derived simply from Freq = Blablabla / Baffle_Width, which surely be the center frequency of the loss area as baffle loss is spanning about several octaves (meaning that the 400Hz doesn't tell much for the x-point design process).
Just an opinion.
Not. The driver geometries are first order determinants of polar pattern and in-room response. So are interdriver spacings and the placement of woofer and midrange with respect to nearby boundaries.
Jay, it's replies like yours that turn relative newcomers off from asking questions in the first place.
If you found my question tiresome and lacking in information, you had two choices: either ask (out of genuine interest and a desire to help) for additional details, or simply refrain from replying and move yourself on to more "audiophile" matters.
Think I'll try this query over at Madisound--I've never had a demonstrative reply like yours at that board.
Mos
NB: thanks for the other replies.
If you found my question tiresome and lacking in information, you had two choices: either ask (out of genuine interest and a desire to help) for additional details, or simply refrain from replying and move yourself on to more "audiophile" matters.
Think I'll try this query over at Madisound--I've never had a demonstrative reply like yours at that board.
Mos
NB: thanks for the other replies.
Hey Mos - take it easy
I think Jay was trying to help.
I don't know him, but his post seems like what I have observed from engineer and anayltical types - they get so hung up in the details they don't think about the niceties - at least he was looking at your situation and trying to help figure it out.
And as far as Madisound goes, I've cetainly been treated far worse there over far less. The internet is like that.
I do think you covered your question reasonably well by saying anywhere within the range would be equally good for both drivers.
having said that - when I recently configured my ative subs for my horns I didn't even think about baffle step, and frankly I don't know how would be the best way to allow for it or if it it needs to be allowed for
I think that part of the problem is that they took your question literally and specifically, while I interpret your questions as asking in general terms with all other things being equal - what things might you take into consideration.
I have no clue as to all of the factors that might be considered in a passive design.
As a general starting point to start calculating - you said "the drivers were good to xover" which I am interpreting as meaning flat to those points
For best integration, You want to cross where you have the most overlap on each side of the crossover point.
this would indicate to me a beginning point for calculations of say around 325 or so.
Figuring that you could go lower than that with a L-R 4th order you could drop that down to around 300 safely and still get good integration - My guess is that if you go below 275 you are likely to lose good integration.
Generally, you want to go as low as you can and still get good integration- the lower you go - the more solid the bass will sound and the less beaming will come into play on the woofers - Also the lower you go the more you keep the crossover effects below that 300hz point.
All this assumes the drivers/cabs, are flat between 200-500
Caveat: this is my unscientific, prejudiced, personal opinion -
And I am telling you basically exactly what I did recently with a Behringer digital crossover.
There I had the luxury of pushing buttons and selecting and playing with it to my hearts content -
For reasons of overlap my theoretical target was 170. I had been told by another owner to expect to cross between 120 to 160.
The best initial setting was 162 - when I had more time, I played with a variety of orders and slopes and crossover points- It sorted down after much playing around and listening to 145hz with a L-R 4th order. Which is of course one of the most common crossover slopes for subs.
As an aside, I was surprised to see how much difference there could be in say 10 hz - which should be the rough equivalent of 20 hz an octave higher - you can hear the difference in just 3 or 4 hz. and there was noticeable difference in 10 hz increments
regards
Ken L
I think Jay was trying to help.
I don't know him, but his post seems like what I have observed from engineer and anayltical types - they get so hung up in the details they don't think about the niceties - at least he was looking at your situation and trying to help figure it out.
And as far as Madisound goes, I've cetainly been treated far worse there over far less. The internet is like that.
I do think you covered your question reasonably well by saying anywhere within the range would be equally good for both drivers.
having said that - when I recently configured my ative subs for my horns I didn't even think about baffle step, and frankly I don't know how would be the best way to allow for it or if it it needs to be allowed for
I think that part of the problem is that they took your question literally and specifically, while I interpret your questions as asking in general terms with all other things being equal - what things might you take into consideration.
I have no clue as to all of the factors that might be considered in a passive design.
As a general starting point to start calculating - you said "the drivers were good to xover" which I am interpreting as meaning flat to those points
For best integration, You want to cross where you have the most overlap on each side of the crossover point.
this would indicate to me a beginning point for calculations of say around 325 or so.
Figuring that you could go lower than that with a L-R 4th order you could drop that down to around 300 safely and still get good integration - My guess is that if you go below 275 you are likely to lose good integration.
Generally, you want to go as low as you can and still get good integration- the lower you go - the more solid the bass will sound and the less beaming will come into play on the woofers - Also the lower you go the more you keep the crossover effects below that 300hz point.
All this assumes the drivers/cabs, are flat between 200-500
Caveat: this is my unscientific, prejudiced, personal opinion -
And I am telling you basically exactly what I did recently with a Behringer digital crossover.
There I had the luxury of pushing buttons and selecting and playing with it to my hearts content -
For reasons of overlap my theoretical target was 170. I had been told by another owner to expect to cross between 120 to 160.
The best initial setting was 162 - when I had more time, I played with a variety of orders and slopes and crossover points- It sorted down after much playing around and listening to 145hz with a L-R 4th order. Which is of course one of the most common crossover slopes for subs.
As an aside, I was surprised to see how much difference there could be in say 10 hz - which should be the rough equivalent of 20 hz an octave higher - you can hear the difference in just 3 or 4 hz. and there was noticeable difference in 10 hz increments
regards
Ken L
Thanks, Ken...
...spot on.
It was obviously a generalised query as in: with all things being equal where, sonically, would be the best place to put the XO point. I've learned an awful lot in the last few months on this and other boards and my question was one of those "fill in the blanks" or "is there anything obvious that I'm missing" type of questions.
Regards
Mos
...spot on.
It was obviously a generalised query as in: with all things being equal where, sonically, would be the best place to put the XO point. I've learned an awful lot in the last few months on this and other boards and my question was one of those "fill in the blanks" or "is there anything obvious that I'm missing" type of questions.
Regards
Mos
Mos, the problem with a question like that is that it really is too general. While there's a certain satisfaction in having an "expert" say definitively "172.55 Hertz," that sort of answer is misleading and in most instances will be wrong. That's why the excellent Mach 1 speakers crossed over at 250 Hz, the excellent NHT 3.3s crossed over at 120 Hz, and the excellent Dynaudio Consequence crossed over at 300 Hz, to pick a few examples.
Musings On Drivers and their cross Over Points
The last post was nice thoughtfull and balanced. Here is my two cents. To point you in the right direction think about the following:
15" 661 hz
12" 912 hz
10" 1065 hz
8" 1302 hz
7" 1540 hz
5" 2051 hz
4" 2687 hz
These are the beginings of the upper limits of the respective drivers. You must always crossover to another at or around the magic numbers to prevent beaming ( beging able to locate the driver by listening rather than having a roughly uniform sound out of your box). The advice on higher order X-overs is good but you need to do some serious modeling on this because they are very finicky little beasts to get exactly what you want. You have to use impedance compensations in the form of a zobel network at the X-over frequency. Nothing writen in stone just a little more info.
P.S. the little chart is from page 105 of the loudspeaker design cookbook. If you don't have it get it
Mark
The last post was nice thoughtfull and balanced. Here is my two cents. To point you in the right direction think about the following:
15" 661 hz
12" 912 hz
10" 1065 hz
8" 1302 hz
7" 1540 hz
5" 2051 hz
4" 2687 hz
These are the beginings of the upper limits of the respective drivers. You must always crossover to another at or around the magic numbers to prevent beaming ( beging able to locate the driver by listening rather than having a roughly uniform sound out of your box). The advice on higher order X-overs is good but you need to do some serious modeling on this because they are very finicky little beasts to get exactly what you want. You have to use impedance compensations in the form of a zobel network at the X-over frequency. Nothing writen in stone just a little more info.
P.S. the little chart is from page 105 of the loudspeaker design cookbook. If you don't have it get it
Mark
>Let's say we have a woofer that is good to xo anywhere up to 500hz and a mid that is good to xo down to 200hz.
If an XO anywhere within that range 200-500hz is just as good for both drivers where should it be? Lower or higher?
BTW, the baffle step -3db point will be around 400hz.
====
As stated it's a no-brainer, 500Hz, since the highest power requirements are in the <500Hz BW and you want the driver with the most acoustic efficiency to cover it.
GM
If an XO anywhere within that range 200-500hz is just as good for both drivers where should it be? Lower or higher?
BTW, the baffle step -3db point will be around 400hz.
====
As stated it's a no-brainer, 500Hz, since the highest power requirements are in the <500Hz BW and you want the driver with the most acoustic efficiency to cover it.
GM
Just curious, Mark, but what cone material is assumed for those magic numbers? Some materials break up worse than others, and so should be crossed at those freqs, but some cones' breakup modes are absolutely tolerable, and so can be considered as full-range without too much trouble. I have some Radio Shack 8"ers that sound comfortably good up to ~10k, even though "by the book" they shouldn't.
In short: every driver is different, so understand the benefits and drawbacks before you pick a point.
In short: every driver is different, so understand the benefits and drawbacks before you pick a point.
Drivers and Compromises
About the table I posted. It's just a guide line. There are as many exceptions to rules as there are rules. It is always the compromises that we make and are willing to put up with that makes up the art of loudspeaker integration. The post about the 8" driver is a good case in point. I to worked with and designed/built 6 1/2" full range drivers a few years back. They can be pushed pretty far up with whizzer cones and phase plugs. What you get is a driver that produces a wider frequency response with smaller peaks and dips than the those equivalent numbers in the table. (Just a side note the table mentions the -3db point of a typical driver of the stated diameter.) But there still are large response anomolies. If you can push these problems up above 3.5 to 4khz it starts to become less noticeable. Just think that few intruments have pure notes above 4khz. It's the harmonics or the part of the notes/music that gives us the richness and fullnes of tone that can go above and beyond our hearing. Cymbals and french horns are two examples that go beyond 40 khz. I don't mean to give the last word but to help people think about the underlying principles as to what and why we make these decisions. A helping hand not a push ar shove. Food for thought only
Mark
About the table I posted. It's just a guide line. There are as many exceptions to rules as there are rules. It is always the compromises that we make and are willing to put up with that makes up the art of loudspeaker integration. The post about the 8" driver is a good case in point. I to worked with and designed/built 6 1/2" full range drivers a few years back. They can be pushed pretty far up with whizzer cones and phase plugs. What you get is a driver that produces a wider frequency response with smaller peaks and dips than the those equivalent numbers in the table. (Just a side note the table mentions the -3db point of a typical driver of the stated diameter.) But there still are large response anomolies. If you can push these problems up above 3.5 to 4khz it starts to become less noticeable. Just think that few intruments have pure notes above 4khz. It's the harmonics or the part of the notes/music that gives us the richness and fullnes of tone that can go above and beyond our hearing. Cymbals and french horns are two examples that go beyond 40 khz. I don't mean to give the last word but to help people think about the underlying principles as to what and why we make these decisions. A helping hand not a push ar shove. Food for thought only
Mark
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