I am impressed with high WAF stereo console projects and want to make someday one for our apartment where the space is pretty limited. There are many of the design variants, but the one that I am leaning to is to have "kinda" 3 way design with shared DVC woofer and 2 mids + 2 tweeters. My shameless edit of well-know project:
The design objectives:
1. High WAF, of course
2. Single shared woofer with DVC, that will play pretty high, up to 400-600 Hz, as I am not worried about stereo presentation much, as there will be limited one because of pretty small c-c distance between mids and tweeters. The space is mostly limited in width. and with this setup I can still make pretty big BR box for woofer.
3. Distance between tweeters is ~1 meter at most, and ~0.8m between mids, or even less. Maybe SICA 5inch coax for combined tw-mid or SBA 4-5 inch NRX or PFCR and small 14-25mm tweeter-supertweeter.
4. Passive design, with normal 3-way stereo crossover(-s). Would like to avoid expensive capacitors, and still to stay with MKP/MKT, no electrolytics.
Right now I see that I am limited with driver selection as the single 10 inch class DVC woofer, that is not rated as subwoofer with 8+8Ohm impedance is Ciare HS251, there are couple 8inch 8+8Ohm from Audax and that is pretty much it. All the others DVC are Dayton subwoofers, mostly 4+4Ohm, which are not suitable for passive 400+Hz crossovers, also I am from EU, where the pricing of Dayton is not that attractive.
There are also an option to go 2x FR drivers with no crossover or the same DVC woofer with 2xFR as WAW/FAST 2-way, but right now full 3-way study is priority.
Also maybe there are other nuances, community brainstorm is very welcome.
The design objectives:
1. High WAF, of course
2. Single shared woofer with DVC, that will play pretty high, up to 400-600 Hz, as I am not worried about stereo presentation much, as there will be limited one because of pretty small c-c distance between mids and tweeters. The space is mostly limited in width. and with this setup I can still make pretty big BR box for woofer.
3. Distance between tweeters is ~1 meter at most, and ~0.8m between mids, or even less. Maybe SICA 5inch coax for combined tw-mid or SBA 4-5 inch NRX or PFCR and small 14-25mm tweeter-supertweeter.
4. Passive design, with normal 3-way stereo crossover(-s). Would like to avoid expensive capacitors, and still to stay with MKP/MKT, no electrolytics.
Right now I see that I am limited with driver selection as the single 10 inch class DVC woofer, that is not rated as subwoofer with 8+8Ohm impedance is Ciare HS251, there are couple 8inch 8+8Ohm from Audax and that is pretty much it. All the others DVC are Dayton subwoofers, mostly 4+4Ohm, which are not suitable for passive 400+Hz crossovers, also I am from EU, where the pricing of Dayton is not that attractive.
There are also an option to go 2x FR drivers with no crossover or the same DVC woofer with 2xFR as WAW/FAST 2-way, but right now full 3-way study is priority.
Also maybe there are other nuances, community brainstorm is very welcome.
With a cross point around 500 Hz, I would be concerned about off-axis performance given your suggested driver spacing. For an application like this, I would normally try to maintain even off-axis response since people are more likely to be way off axis with TV viewing or background listening. If your listening positions are only directly in front the speaker, this may be less important to you though.
Just a rough model using one side driver and the woofer, but at 500 Hz 12 dB/octave cross and 19.5 inches of horizontal driver spacing, at 20° off axis horizontally you are looking at something like this:
How it all combines in real life when both left and right are playing along with the woofer is harder to predict, since it would vary based on where something is in the soundstage.
I've been messing around with a similar idea, but using two 10-inch woofers and having them as close as possible to the co-ax's. The height of the cabinet got a bit large for my tastes, and the woofer got discontinued, so now I'm considering the SB Acoustics SB23NRXS45-4. It should do pretty well in a reasonably small, ported enclosure.
Just a rough model using one side driver and the woofer, but at 500 Hz 12 dB/octave cross and 19.5 inches of horizontal driver spacing, at 20° off axis horizontally you are looking at something like this:
How it all combines in real life when both left and right are playing along with the woofer is harder to predict, since it would vary based on where something is in the soundstage.
I've been messing around with a similar idea, but using two 10-inch woofers and having them as close as possible to the co-ax's. The height of the cabinet got a bit large for my tastes, and the woofer got discontinued, so now I'm considering the SB Acoustics SB23NRXS45-4. It should do pretty well in a reasonably small, ported enclosure.
@mattstat
If I understood you well, the pretty high crossover, lets say at 500Hz and the spacing will be the cause of that dip at ~630Hz @ 20 degrees hor?
Probably the easiest way is to build 2 elongated bookshelves, join them together and call it a day, but I want that coolness factor of single woofer ant 2 small mids on the sides 🙂
If I understood you well, the pretty high crossover, lets say at 500Hz and the spacing will be the cause of that dip at ~630Hz @ 20 degrees hor?
Probably the easiest way is to build 2 elongated bookshelves, join them together and call it a day, but I want that coolness factor of single woofer ant 2 small mids on the sides 🙂
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Ok, I tried to sim this quick n dirty. Now more questions, than answers.
With 300mm X spacing between woofer to mid c-c, everything seems manageable, crossover at ~300Hz, that bump on 1khz is BSC, so do not care for now.
With 400 mm and ~350Hz crossover it gets uglier:
The main question is if that anomaly on ~500Hz is inside the listening space or outside???
300mm c-c it is not much uglier than some reviews on ASR.
I would like to experiment of this one, but the drivers are expensive, and I will have no use for 8+8Ohm DVC woofer if this will not work.
With 300mm X spacing between woofer to mid c-c, everything seems manageable, crossover at ~300Hz, that bump on 1khz is BSC, so do not care for now.
With 400 mm and ~350Hz crossover it gets uglier:
The main question is if that anomaly on ~500Hz is inside the listening space or outside???
300mm c-c it is not much uglier than some reviews on ASR.
I would like to experiment of this one, but the drivers are expensive, and I will have no use for 8+8Ohm DVC woofer if this will not work.
Yes. It's fallout from the varying distance to each driver as you move off axis. Typical suggestion is to keep drivers at 1/4 wavelength spacing at the cross point (or under) if you want good off-axis behavior. This often can't be done in practice, so most designs have some amount of trouble along the axis where the drivers have spacing. This is normally the vertical axis, so in reviews there's often a restricted range on that axis and much worse performance than horizontal. Since you've flipped spacing to horizontal, that's your trouble axis.
You can mock up your design with other drivers if you have some handy. It doesn't have to be with the final ones or even with a dual-voice coil driver. You can use a summed signal for the woofer if you have an extra amp channel handy and some other parts around.
It does not look asymmetric, it is 2nd order both of them. Or is it asymmetric because of the actual tweeter slopes are more aggressive?
The whole idea is loosing its "magic" - just forgot that all the ver lobbing and problems are transferred to hor. 2 joined together bookshelves are not that badass.
...it is hard for me to admit, but I still do not know how to read and what to expect from phase charts, but I do understand what the wave phase is...
In this case one being ahead of the other gets them to meet up more to the right or left. You can wave your mic in front of them and find the peak, then tilt it on the simulator by offsetting the crossover a little at a time.
You are talking about Z depth? In that case difference in Z has to be substantial to have some influence.
Why don't you try delaying in vituixcad to change the phase alignment. The polar map has a sudden colour change which looks worse than it is.
Thanx - I will when have some time. But just as the study. In the production I don't want to be dependent on delay, as this is passive design. Active is too expensive for me and I have some amp boxes around.