@gedlee with my woofers placed in/near the corners of the room, Fr has been really good for the low end. My experiments with Rew room sim show no significant improvement by surrounding myself with quadratic stereo subwoofers. It's also space saving to just keep things co located in the corner in a single cabinet.
If I use 1 18" front firing on the front baffle, I have 5 baffles and 2 more 18"s to play with. The question is where to place them? They would be crossed to allow 1/4th wave length coupling. I can fit the 2 additional woofers diagonally on one baffle or just one per baffle.
So now that you see the possibilities, what would you chose? Given the corner type placement and close 1m listen distance what would be optimal? I could see the additional woofers being place top and bottom or bottom and rear or left/right side... or 2 on rear baffle etc etc but whats the one to desire if painted into this corner?
If I use 1 18" front firing on the front baffle, I have 5 baffles and 2 more 18"s to play with. The question is where to place them? They would be crossed to allow 1/4th wave length coupling. I can fit the 2 additional woofers diagonally on one baffle or just one per baffle.
So now that you see the possibilities, what would you chose? Given the corner type placement and close 1m listen distance what would be optimal? I could see the additional woofers being place top and bottom or bottom and rear or left/right side... or 2 on rear baffle etc etc but whats the one to desire if painted into this corner?
We are getting there, I have one cabinet that I am wanting to develop to be placed in/near the corner. A front firing 18" on the front baffle to mate with the horn, and then what to do with the additional 2 18"s. I would cross them to maintain 1/4wl coupling throughout their passband. I think you like the idea of 2 on the floor facing baffle??? Other possibilities left snd right side? Top and bottom, bottom and rear, 2 on bottom, 2 on rear etc etc
Whats the desire-able one for my given details such as 1m listening, corner located, 1/4wavelength pass.
If you know me then you should realize that I find nonlinear distortion measurements to be mostly pointless and almost irrelevant. You can find things that are broken with them, but that's about all.
So you didn't measured them in the case of the NS15 for example? Just asking.
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Depending on the placement on the box it will tell me my limitation. To rear of the box is ~32". If I mounted them underneath diagonally, you could say about 16" to the center of both drivers. I'll would chose the xo points based off of 1/4wl spacing is what I mean.
My main concern is choosing the desired configuration for the woofers given corner loading and close proximity listening.
YSDR, now that it's common knowledge that the increased source impedance of a passive crossover tends to reduce measured nonlinear distortion, have you ever wondered why many active crossover aficionados didn't stop to complain about the increased distortion?
I don't recall that happening, they mostly talked about clean sound. While some may disagree as to the cause of that, today's point is that they noticed a linear effect, and they didn't notice a nonlinear effect.
I don't know, but IMD distortion is fundamentally very different compared to HD distortion.
So just taken them all in one sentence if they are equal makes no sense.
I think you should even know that.
I am not saying that we have to go down to insanely low levels, there is most definitely a threshold.
But just dumping blunt statements that they are only good for finding out if things are broken is far to simplified.
Besides, from a practical point of view exact absolute numbers are less important, but knowing when distortion either ramps up, or when issues like cone break-ups are starting to occur are absolutely a must for a good a proper loudspeaker design.
So in that regard it is actually EXTREMELY relevant to know.
Even more so when people have no choice to go for smaller drivers for whatever reason.
If you have the luxury, money, space, WAF for going very big at baby sound pressure levels + you don't mind a very tight directivity and sweetspot.
As well as using mid-woofers that don't create any modulation products because of the lack of excursion.
Sure, it doesn't really matter.
But that is putting the entire argument totally out of context and fitting it into a very specific niche.
Meaning an asterisk is needed with such statements.
I am reluctant to respond to a critique from someone who clearly does not understand linear/nonlinear systems theory. You need to understand it before you can critique it.
1)"IMD distortion is fundamentally very different compared to HD distortion" This is incorrect. They are both symptomes of the same underlying nonlinearity, just using different probe signals. With sufficient information, I can calculate one from the other, implying that they are not independent and as such are basically just different ways of looking at the same thing
2)"when issues like cone break-ups are starting to occur are absolutely a must" Cone breakup is a linear phenomena- not nonlinear - and as such has no bearing on my comment.
3)"But that is putting the entire argument totally out of context" The context here is very clear - hi output loudspeaker of premium quality and not run-of-the-mill BT mini-monitors. Hence it is your comment "people have no choice to go for smaller drivers for whatever reason" is the one that is out of context.
1)"IMD distortion is fundamentally very different compared to HD distortion" This is incorrect. They are both symptomes of the same underlying nonlinearity, just using different probe signals. With sufficient information, I can calculate one from the other, implying that they are not independent and as such are basically just different ways of looking at the same thing
2)"when issues like cone break-ups are starting to occur are absolutely a must" Cone breakup is a linear phenomena- not nonlinear - and as such has no bearing on my comment.
3)"But that is putting the entire argument totally out of context" The context here is very clear - hi output loudspeaker of premium quality and not run-of-the-mill BT mini-monitors. Hence it is your comment "people have no choice to go for smaller drivers for whatever reason" is the one that is out of context.
No, I am not in the habit of making measurements that do not provide any useful information.
Once again I seem to have to point out that IMD and HD have never been shown to be correlated to perception. They are just numbers with no link to sound quality (except if the speakers are broken of incompetent.)
"If you have the luxury, money, space, WAF for going very big at baby sound pressure levels + you don't mind a very tight directivity and sweetspot.
As well as using mid-woofers that don't create any modulation products because of the lack of excursion."
Hey I resemble that remark- at least the WAF part and system design. I've always biased towards larger systems and I describe it as "ease" of presentation. I can hear a small midbass' character in the bass and midbass compared to larger drivers, though admittedly I haven't heard the seemingly superb offerings from Purifi. The best drivers do this less, but the best solution for driver sound quality in many cases is just to ask less excursion/power from it. I much prefer the character of a massively over-scaled system, despite requiring large speakers/complexity, but delays and integration are what multi-amping and DSP are for. I feel like bass arrays get under-represented- there's a lot you can do with shaded arrays that offer significant performance advantages over some of the complex cabinets we build for higher-efficiency woofers. I do pay for quality drivers, with shorting paths and other features, despite the use case being "easy mode".
As well as using mid-woofers that don't create any modulation products because of the lack of excursion."
Hey I resemble that remark- at least the WAF part and system design. I've always biased towards larger systems and I describe it as "ease" of presentation. I can hear a small midbass' character in the bass and midbass compared to larger drivers, though admittedly I haven't heard the seemingly superb offerings from Purifi. The best drivers do this less, but the best solution for driver sound quality in many cases is just to ask less excursion/power from it. I much prefer the character of a massively over-scaled system, despite requiring large speakers/complexity, but delays and integration are what multi-amping and DSP are for. I feel like bass arrays get under-represented- there's a lot you can do with shaded arrays that offer significant performance advantages over some of the complex cabinets we build for higher-efficiency woofers. I do pay for quality drivers, with shorting paths and other features, despite the use case being "easy mode".
Ok, Ive been working so much lately all I do is go home and eat and fall asleep so I haven't been able to draw an illustration so I can help you guys help me.
@gedlee @GM @weltersys
@b_force
Again...
I am getting great FR at my 1meter via corner placement. Unless there is some other benefit, I am not certain the traditional approach of multi sub is needed here. In rew room sim, it shows no FR improvement with quadratic stereo subwoofers, ie, 2 rear subs accompanying the corner full range mains.
My woofer box is 26"tall 32" wide 32" deep
Leys say I place one 18" woofer on the front baffle, front firing. What to do with the remaining two 18 inch woofers, in order to incorporate them into this cabinets. Wherever I decide to place some on the cabinet I would cross them in order to maintain 1/4 wave length coupling through their pants band.
I could place them on the top and bottom baffle, left snd right baffle, bottom and rear baffle... I can even squeeze 2 18s on one baffle if staggered diagonally.
Please tell me what you would choose and why 😀
@gedlee @GM @weltersys
@b_force
Again...
I am getting great FR at my 1meter via corner placement. Unless there is some other benefit, I am not certain the traditional approach of multi sub is needed here. In rew room sim, it shows no FR improvement with quadratic stereo subwoofers, ie, 2 rear subs accompanying the corner full range mains.
My woofer box is 26"tall 32" wide 32" deep
Leys say I place one 18" woofer on the front baffle, front firing. What to do with the remaining two 18 inch woofers, in order to incorporate them into this cabinets. Wherever I decide to place some on the cabinet I would cross them in order to maintain 1/4 wave length coupling through their pants band.
I could place them on the top and bottom baffle, left snd right baffle, bottom and rear baffle... I can even squeeze 2 18s on one baffle if staggered diagonally.
Please tell me what you would choose and why 😀
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No need to throw with poop or attack people personally, just stay on the subject.
I expect much more professional and mature behavior from people with a certain background.
Camplo,
Unless your basement room is quite small (you have not shared dimensions) you seem to have departed from the 1 meter listening distance concept you had been touting for a few years.
I have told you what I'd choose to do with your choice of loudspeakers in corners in post 13374 and why in dozens of posts prior.
Art
Unless your basement room is quite small (you have not shared dimensions) you seem to have departed from the 1 meter listening distance concept you had been touting for a few years.
I have told you what I'd choose to do with your choice of loudspeakers in corners in post 13374 and why in dozens of posts prior.
Art
Okay explain to me this why people like Klippel take these different kinds of distortion very differently?
They even provide a threshold reference in their graphs (I think it's around 3%) which indicates where either/or IMD or HD distortion is to high.
BL(x) for example is a very obvious result of modulation distortion.
Where the entire higher frequency part of a loudspeaker modulates because the low-end creates a bigger cone excursion.
While Cms(x) only results in HD distortion.
Although exaggerated, people from Purifi very clearly show this difference
https://purifi-audio.com/blog/tech-...o-whats-the-point-of-low-distortion-drivers-4
So from there we can already conclude that most definitely and factually not every distortion is the same.
They are in fact far from "being the same underlying principle".
Read my comment again, because it's obvious that this is not what I wrote.
Everyone who has designed loudspeakers, knows that at a certain point distortion level will ramp up close to cone-break up. Which is reflected in motor system at higher order harmonics at lower frequencies.
Although you can say that those levels are not audible, the huge ramping up of the distortion near cone break-up or in the low-end near Fs is very significantly
Sorry but this is just a straight up dumb comment and you absolutely know this yourself.
It even sounds incredibly rude and disrespectful.
First of all, there are actually very high-quality BT-monitors, with objectively the best performing premium drivers and directivity.
Or are we now all of a sudden saying that bluetooth isn't good enough?
I thought that you just said that distortion doesn't matter?
Meaning that BT is most definitely good enough!
Which makes the entire point invalid.
Second, even if that would not be the case, it's just silly to assume there is nothing in between cheap BT and big 15 inch monsters. Unless you call anything else just cheap stuff?
A 5 inch can be perfectly premium quality, but still inherently has its limitations.
One of them is that you WILL start to hear distortion if sound pressure levels go up.
Meaning that a driver with better distortion numbers will provide headroom as well a leverage in the entire system design.
Particularly talking about modulation products here, since we have no other way than using more cone-excursion = more intermodulation distortion.
So no, this is actually very much into context and it would be very much appreciated if you could have a more constructive and respectful way of discussing the matter.
I am not asking for personal attacks, don't appreciate those and I most definitely expect an higher quality level from certain people.
Thank you for taking the time to reply, I also would envision the solution you suggest to be a superior option it's just not something that is feasible for my location. Maybe in future with a more permanent location, I could pull something like this off, so with that being said, and being limited to the options that I presented in my last post what configuration would you choose???
I am working in what is basically a long rectangle which is about 13 feet wide and 8 feet tall and some 30 feet long. me and the system are to be located on one side of the triangle which easily supports corner loading with the chair in the middle and about 5-6 feet away from the front wall. I do not wish to relocate the listening position
Free standing soffits or gobos (movable acoustic isolation panels) can easily be moved to any location..
I wouldn't limit the options to those presented in your last post, even if I understood what you were trying to accomplish:
If limited to one sub, I'd probably center it.
I might put each of the slot load 2x18" sub boxes in the corners.
I would put the HF horns above separate ~100Hz to ~400Hz mid-bass boxes, and place the mid-high for optimum coverage of the chosen listening position, either on top of the subs or on pedestal boxes to bring the center of the mid-high to ear height.
Assuming you haven't sold your 15" mid-bass boxes, I'd certainly use them rather than buying 18" for mid bass, or pulling one of the slot load 2x18" apart to use the drivers for low mid range.
If you had sold the mid-bass boxes, I might build a horn mid-bass with around the same depth as your high horn so the acoustic points of mid/high origin would not shift when listening off-axis.
Art
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These boxes I am trying to design are to replace the slot loading idea. So they're two 26" high by 32" dept and width boxes, to design with. The front of the box will be the woofer crossing to the Horn. Lets leave that there, because whether its the 15" or 18" it will remain front firing on the front baffle. I have 2 more 18"s for each box, that I'd like to incorporate into the same cabinet. If I have design separate compartments into this box, it is inconsequential.
being my close listening proximity, and corner placement of the speaker, do you think I should have left and right baffle for the 2 additional 18"s per 26" high by 32" dept and width box that has the horn sitting on top of it............ or Bottom and rear baffle? Or top and bottom baffle? I can even fit 2 woofers diagonally on a baffle so 2 on the rear or bottom for example.... No matter where the two additional woofers are placed on the box that also houses the front firing woofer that crosses to the horn thats sitting on top of the box.... They will be low passed in order to maintain 1/4wl coupling, with the front firing woofer... that is on the front baffle of the 26" high by 32" dept and width, box....that also has the horn sitting on top of it.... placed in the corners.
being my close listening proximity, and corner placement of the speaker, do you think I should have left and right baffle for the 2 additional 18"s per 26" high by 32" dept and width box that has the horn sitting on top of it............ or Bottom and rear baffle? Or top and bottom baffle? I can even fit 2 woofers diagonally on a baffle so 2 on the rear or bottom for example.... No matter where the two additional woofers are placed on the box that also houses the front firing woofer that crosses to the horn thats sitting on top of the box.... They will be low passed in order to maintain 1/4wl coupling, with the front firing woofer... that is on the front baffle of the 26" high by 32" dept and width, box....that also has the horn sitting on top of it.... placed in the corners.
Why?
The slot is not a problem if you use the sub woofers below ~100 Hz.
From the height dimension you have chosen, perhaps you like you like to sit on the floor in the lotus position, or you like the sound source below you. I don't like either of those choices.
An equilateral triangle between the speakers and listening position is fairly typical.
The corner to corner distance is going to fix your listening triangle distance.
Putting the subwoofers and front firing mid bass in the same cabinet is a self-imposed restriction that will reduce your positioning and proximity options, cost you more time and expense while reducing the potential for a balanced system and LF corner gain.
Why make more work for yourself when it won't have a positive outcome?
No.
Hmm, this + 1 m LP distance implies you'll be moving the speakers from near the chair to hard in the corners? This ideally puts all drivers on the front to moving the dual woofers to on the back or sides and 'gapped' to 'taste' in the corners, so best compromise in this case for me is one on each side.