Hi all,
I've been pumping out cabinets for my single bass array, but needed a side quest to break up the flow and have a little fun. I really like fiddling with open baffle and I like the sound, but I also wanted to use the dipole effect for a real purpose in my upcoming room it will be in I think which is a long 40 foot room spanning the house with one end is the living room and the other end is the kitchen. I'd like to try out some large open baffles in the living room that will see daily use for all kinds of content so that the family can be loud and whatever in the living room, and the kitchen will be a far distance and 90 degree's off axis from these dipoles. So hopefully you can have a conversation in the kitchen without loud Lord of the Rails, Thomas the Engine, etc, barking from the 5 year old watching his shows and all that. Obviously not a hifi listening space lol. So this lets me satisfy the itch of building a new open baffle and experimenting and having a real place and purpose for it, and not just another pair of speakers to find a place for in the house.
With the looming economy and unclear duties shipping from over seas to USA, I was very weary to order some of the drivers I really wanted. I happened to find some Lii Song F-6's locally for a little more than the retail cost. These are budget drivers, no doubt, they're like $60 MSRP from China from Lii Song. But, I love the look and I like whizzer cones. I really wanted Fast 8's or The 12's or 15's even, but I didn't want to find out what duties I would swallow after paying, shipping and then double the cost or something from duties due to tariffs. So I just sat that out. Maybe in a few years I'll order a pair of what I really want. But until then, just gonna play with what's local. I just like the look of the Lii Songs, Tangs and a few Fostex that have that cream color bone color woofer cones, and like how they match organically in look to hard wood.
I have 4x GRS 8SW4HE drivers sitting around for projects and figured I'd try them out. They're not optimal for open baffle, but they have good power handling and excursion so I'll see if I can make it work with them instead of buying more stuff. My heart wanted 4x15's on these, but I also want to see the wood of the baffle and really didn't want to spend $500+ just to get a little bit more towards 30hz. We will see.
So experimenting with questionable combinations of drivers on a baffle.
My long term goal is to use two large mirror oak slabs that I have for the final iteration of this potentially. I'm going to experiment and develop on plywood baffles of similar dimensions to get the bulk of the effort done first though.
These are about 18 inches wide nominal and over 70 inches tall. Pretty flat. But I'll have to work them if I get to use them. My goal is to pick out about 50~55 inches of length from these and shorten it but keep all the live edge sides (bark removed). So knowing that, the shortest baffle dimension is around 18 inches. So planning around how 18 inches will factor into things.
I have some other drivers that I was interested in trying. So I did some overlays to see how it would look.
I have some PT6816 planar magnetic wide bands, a mid-woofer, the Lii F6's and the GRS 8's, so just to see how some arrangements might look. I also looked at how a MA200 Mark Audio and CHN110 Mark audio and CHR120 Mark audio might look on such slabs. They are not perfectly scaled here, just looking at how the drivers look with the slabs.
Not to scale:
I much prefer the warmer cones of the Marks and Lii's here. The Marks have low Qts and the Lii has higher Qts, so figured, for this I'll try the Lii's. Found them locally for an acceptable price so they were cheap.
I paid about $40 per driver new ($30 MSRP from China each, but lord knows what duties and shipping would have been, not worth it for cheap drivers like this).
Maybe after the tariff war nonsense if things get better, I'll feel better about ordering some Fast 8's or Fast 15's. These cheap F-6's will scratch the itch until then I suppose.
Then just for fun, how could the arrangements look with the GRS 8's and the drivers I have:
Didn't like these.
I think I like the Woofer Lii Woofer best (the look):
So will probably move forward with the Woofer Wideband Woofer arrangement on the baffles.
Very best,
I've been pumping out cabinets for my single bass array, but needed a side quest to break up the flow and have a little fun. I really like fiddling with open baffle and I like the sound, but I also wanted to use the dipole effect for a real purpose in my upcoming room it will be in I think which is a long 40 foot room spanning the house with one end is the living room and the other end is the kitchen. I'd like to try out some large open baffles in the living room that will see daily use for all kinds of content so that the family can be loud and whatever in the living room, and the kitchen will be a far distance and 90 degree's off axis from these dipoles. So hopefully you can have a conversation in the kitchen without loud Lord of the Rails, Thomas the Engine, etc, barking from the 5 year old watching his shows and all that. Obviously not a hifi listening space lol. So this lets me satisfy the itch of building a new open baffle and experimenting and having a real place and purpose for it, and not just another pair of speakers to find a place for in the house.
With the looming economy and unclear duties shipping from over seas to USA, I was very weary to order some of the drivers I really wanted. I happened to find some Lii Song F-6's locally for a little more than the retail cost. These are budget drivers, no doubt, they're like $60 MSRP from China from Lii Song. But, I love the look and I like whizzer cones. I really wanted Fast 8's or The 12's or 15's even, but I didn't want to find out what duties I would swallow after paying, shipping and then double the cost or something from duties due to tariffs. So I just sat that out. Maybe in a few years I'll order a pair of what I really want. But until then, just gonna play with what's local. I just like the look of the Lii Songs, Tangs and a few Fostex that have that cream color bone color woofer cones, and like how they match organically in look to hard wood.
I have 4x GRS 8SW4HE drivers sitting around for projects and figured I'd try them out. They're not optimal for open baffle, but they have good power handling and excursion so I'll see if I can make it work with them instead of buying more stuff. My heart wanted 4x15's on these, but I also want to see the wood of the baffle and really didn't want to spend $500+ just to get a little bit more towards 30hz. We will see.
So experimenting with questionable combinations of drivers on a baffle.
My long term goal is to use two large mirror oak slabs that I have for the final iteration of this potentially. I'm going to experiment and develop on plywood baffles of similar dimensions to get the bulk of the effort done first though.
These are about 18 inches wide nominal and over 70 inches tall. Pretty flat. But I'll have to work them if I get to use them. My goal is to pick out about 50~55 inches of length from these and shorten it but keep all the live edge sides (bark removed). So knowing that, the shortest baffle dimension is around 18 inches. So planning around how 18 inches will factor into things.
I have some other drivers that I was interested in trying. So I did some overlays to see how it would look.
I have some PT6816 planar magnetic wide bands, a mid-woofer, the Lii F6's and the GRS 8's, so just to see how some arrangements might look. I also looked at how a MA200 Mark Audio and CHN110 Mark audio and CHR120 Mark audio might look on such slabs. They are not perfectly scaled here, just looking at how the drivers look with the slabs.
Not to scale:
I much prefer the warmer cones of the Marks and Lii's here. The Marks have low Qts and the Lii has higher Qts, so figured, for this I'll try the Lii's. Found them locally for an acceptable price so they were cheap.
I paid about $40 per driver new ($30 MSRP from China each, but lord knows what duties and shipping would have been, not worth it for cheap drivers like this).
Maybe after the tariff war nonsense if things get better, I'll feel better about ordering some Fast 8's or Fast 15's. These cheap F-6's will scratch the itch until then I suppose.
Then just for fun, how could the arrangements look with the GRS 8's and the drivers I have:
Didn't like these.
I think I like the Woofer Lii Woofer best (the look):
So will probably move forward with the Woofer Wideband Woofer arrangement on the baffles.
Very best,
I tried to model with Edge & Basta to get an idea of what to expect with these. I know they will roll off early. The baffle width is 18", so it'll start around 750hz or so and really kick in lower some where in the hundreds of hz. Overall I'm not trying to be too specific since my final baffles will not be perfect geometry so I know I'll have to just fiddle and tinker with things as I go. Part of the fun!
Edge:
Looking at the wideband placement first since it will cover everything until somehwere between 100~300hz range I think.
Center arrangement prediction has a nasty cancellation around 1300hz.
Off center, about 1/3rd of the baffle looks better:
Looks like the roll off really starts under 300hz as expected.
Finally, closer to center but off center a tiny bit vertically and more like 1/4th or 1/5th baffle width placement, I see this prediction:
Ultimately not sure which will matter most, but I figure I should hang onto any bass efficiency I can and also want to keep the wideband approximately ear height while seated in typical height seating.
Basta:
Went into Basta to get a look at things too. Ultimately I liked what I saw with this placement on the baffle dimensions:
So maybe somewhere near 200hz I'll see if I can cross my woofers and see how that looks.
Very best,
Edge:
Looking at the wideband placement first since it will cover everything until somehwere between 100~300hz range I think.
Center arrangement prediction has a nasty cancellation around 1300hz.
Off center, about 1/3rd of the baffle looks better:
Looks like the roll off really starts under 300hz as expected.
Finally, closer to center but off center a tiny bit vertically and more like 1/4th or 1/5th baffle width placement, I see this prediction:
Ultimately not sure which will matter most, but I figure I should hang onto any bass efficiency I can and also want to keep the wideband approximately ear height while seated in typical height seating.
Basta:
Went into Basta to get a look at things too. Ultimately I liked what I saw with this placement on the baffle dimensions:
So maybe somewhere near 200hz I'll see if I can cross my woofers and see how that looks.
Very best,
Received the Lii Song F6's from a 3rd party retailer on Amazon in 3 days. Sure wish they carried the Fast series.
Back of the driver. Not sure I believe the T&S, will test.
Face of the driver, lovely cream cone, whizzer, I like the look.
Measured on DATS and then ran them to moderate excursion (or high excursion for them) to see their behavior and sort out if they're lemons or not.
Cold DATS out of the box:
F&S is double what they claimed on the back of the driver lol.
With a jig placed for scale, I gave them some excursion to break them in and then measured them again the next day after a few hours of 30hz with about 3~4mm of peak to peak excursion.
I scale measured them to 4.6mm peak to peak excursion at 7.5V in free air, so maybe 2mm xmax is the practical limit.
After the break in, here's the new DATS. Fs came down a bit. Still, no where near published 40's hz. That's fine though.
Very best,
Back of the driver. Not sure I believe the T&S, will test.
Face of the driver, lovely cream cone, whizzer, I like the look.
Measured on DATS and then ran them to moderate excursion (or high excursion for them) to see their behavior and sort out if they're lemons or not.
Cold DATS out of the box:
F&S is double what they claimed on the back of the driver lol.
With a jig placed for scale, I gave them some excursion to break them in and then measured them again the next day after a few hours of 30hz with about 3~4mm of peak to peak excursion.
I scale measured them to 4.6mm peak to peak excursion at 7.5V in free air, so maybe 2mm xmax is the practical limit.
After the break in, here's the new DATS. Fs came down a bit. Still, no where near published 40's hz. That's fine though.
Very best,
Next up, test baffle iteration one.
I took some scrap plywood to make a test baffle.
I went with 1/3rd off center towards an edge with the wideband.
I centered the woofers, they're about 20 inches center to center space (0.5 meters)
About 10 inches center to center from the wide band to the center of either woofer (0.25 meters)
Just a hopefully transparent kickstand to hold them up while testing things. Final version will have something different. I did this just to have easy access to the drivers and stuff while testing and tinkering.
54" (1.37m) x 18" (0.457m) final baffle size.
Driver fitting.
I really like the look of drivers behind the baffle to hide the mounting flange. But, I know that it can make a mess with the mids-treble range with the cavity as a pseudo-waveguide and flip phase and stuff. Still, I'll test on both sides of the baffle to see how bad it is.
The Lii is probably best mounted on the front, flush.
But, I want to see how bad it is from behind the baffle just in case its tolerable.
Just to get an idea of the arrangement, baffle size, placement, etc. The hardware is temporary (machine screws and washers and nuts). Final version will not have hardware on the front of the baffle. This is just testing iteration 1.
Very best,
I took some scrap plywood to make a test baffle.
I went with 1/3rd off center towards an edge with the wideband.
I centered the woofers, they're about 20 inches center to center space (0.5 meters)
About 10 inches center to center from the wide band to the center of either woofer (0.25 meters)
Just a hopefully transparent kickstand to hold them up while testing things. Final version will have something different. I did this just to have easy access to the drivers and stuff while testing and tinkering.
54" (1.37m) x 18" (0.457m) final baffle size.
Driver fitting.
I really like the look of drivers behind the baffle to hide the mounting flange. But, I know that it can make a mess with the mids-treble range with the cavity as a pseudo-waveguide and flip phase and stuff. Still, I'll test on both sides of the baffle to see how bad it is.
The Lii is probably best mounted on the front, flush.
But, I want to see how bad it is from behind the baffle just in case its tolerable.
Just to get an idea of the arrangement, baffle size, placement, etc. The hardware is temporary (machine screws and washers and nuts). Final version will not have hardware on the front of the baffle. This is just testing iteration 1.
Very best,
Some quick dirty measurements to see how it behaves and how the roll off looks. I'm not trying to get anechoic measurements at this stage, just getting an idea of the overall shape.
This is the Lii F6 on the test baffle by itself just a raw sweep at distance. Again, no correction, just seeing the initial shape potential. I see right away 3~5khz range has two nasty peaks with significant amplitude. Likely the cavity from the driver mounted from behind the baffle I imagine. Also a peak around 900hz with significant amplitude. The rest is tolerable looking and seems to do ok down to about 200~300hz then rolls off significantly under 100hz as expected.
Here's the GRS8's in series on the baffle mounted from behind, long sweep just to see entire behavior. Not corrected for. Not near field. All I'm looking at is how they behave from the bottom to about 500~600hz. Above that it gets nasty. They roll off naturally under 60hz. But from 60hz to 600hz there's plenty to work with there it seems.
GRS 8's impedance sweep and T&S on the baffle.
Lii F6 on the baffle impedance and T&S.
With a DSP, I'm just looking at potential crossing points to see how it looks. Here I'm crossing around 280hz or so and keeping the woofers output higher so I can shape and cut, later will boost output to 30hz range if I can.
In the T.racks 4x Mini Pro, I'm trying a new notches on those peaks and high passing it around 200hz.
Most of the notches in place as above. Then lifted bass and crossed.
Did some shelving and high pass on the woofers, just to keep them behaved but push them pretty hard towards 30hz to see if I can get that up to flat or better. These 8's have 11mm excursion and can handle it pretty nicely, just inefficient to do it, but maybe it will work. Will find out.
Re-shaping the wide band, shelving the top and bottom for a bit more of a curve and to tame the whizzer treble area but also lift a bit towards where I'm crossing to smooth that out if I can.
Landed here for now. I know this is not flat. This is also not corrected or anechoic or anything. Again, just shaping to see rough form of curve to see what's even possible and if these drivers will even work out on this baffle size, or if I need to abandon them and get different drivers for this. So far, this crude curve looks ok to me. It sounds fairly good surprisingly just listening to content I'm familiar with. The bass is significant which is nice, the 8's are surprisingly capable with the power behind them. The excursion and power overcomes the dipole cancellation to a degree and the lack of baffle width. It can't do anything more than 30~40hz though, it tanks under that and cannot give any more. Some prefer flat, but I do not, I like it warmer and heavy towards 30hz and with whizzers I like a rolled off treble top. For a smooth warm listen. Again, this is not final, just seeing what's possible with the DSP and if these can be made to work out and sound ok to be comfortable with moving forward with them.
Next, I need to test the Lii F6 on the front of the baffle, flush, to see if I can get away with less notches.
I also need to test adding wings behind the baffle to help the bass response a little more. Foam board testing time.
Very best,
This is the Lii F6 on the test baffle by itself just a raw sweep at distance. Again, no correction, just seeing the initial shape potential. I see right away 3~5khz range has two nasty peaks with significant amplitude. Likely the cavity from the driver mounted from behind the baffle I imagine. Also a peak around 900hz with significant amplitude. The rest is tolerable looking and seems to do ok down to about 200~300hz then rolls off significantly under 100hz as expected.
Here's the GRS8's in series on the baffle mounted from behind, long sweep just to see entire behavior. Not corrected for. Not near field. All I'm looking at is how they behave from the bottom to about 500~600hz. Above that it gets nasty. They roll off naturally under 60hz. But from 60hz to 600hz there's plenty to work with there it seems.
GRS 8's impedance sweep and T&S on the baffle.
Lii F6 on the baffle impedance and T&S.
With a DSP, I'm just looking at potential crossing points to see how it looks. Here I'm crossing around 280hz or so and keeping the woofers output higher so I can shape and cut, later will boost output to 30hz range if I can.
In the T.racks 4x Mini Pro, I'm trying a new notches on those peaks and high passing it around 200hz.
Most of the notches in place as above. Then lifted bass and crossed.
Did some shelving and high pass on the woofers, just to keep them behaved but push them pretty hard towards 30hz to see if I can get that up to flat or better. These 8's have 11mm excursion and can handle it pretty nicely, just inefficient to do it, but maybe it will work. Will find out.
Re-shaping the wide band, shelving the top and bottom for a bit more of a curve and to tame the whizzer treble area but also lift a bit towards where I'm crossing to smooth that out if I can.
Landed here for now. I know this is not flat. This is also not corrected or anechoic or anything. Again, just shaping to see rough form of curve to see what's even possible and if these drivers will even work out on this baffle size, or if I need to abandon them and get different drivers for this. So far, this crude curve looks ok to me. It sounds fairly good surprisingly just listening to content I'm familiar with. The bass is significant which is nice, the 8's are surprisingly capable with the power behind them. The excursion and power overcomes the dipole cancellation to a degree and the lack of baffle width. It can't do anything more than 30~40hz though, it tanks under that and cannot give any more. Some prefer flat, but I do not, I like it warmer and heavy towards 30hz and with whizzers I like a rolled off treble top. For a smooth warm listen. Again, this is not final, just seeing what's possible with the DSP and if these can be made to work out and sound ok to be comfortable with moving forward with them.
Next, I need to test the Lii F6 on the front of the baffle, flush, to see if I can get away with less notches.
I also need to test adding wings behind the baffle to help the bass response a little more. Foam board testing time.
Very best,
Testing another baffle mounting for the Lii, I cut another 18" baffle and cut out a hole and rabbet cut out a place for the flange and it now is flush with the baffle to test that.
I have a tiny gap that I could have made a bit better here, so, will make note of that on the next prototype.
Overall, I'm ok with the look of it being front flush mounted. I prefer the look of the driver mounted from behind the baffle and no hardware to be seen.
Baffle 1 (red) mounted from behind
Baffle 2 (blue) mounted flush on the front
Separated more so we can examine them. The 3khz spike is gone. The 4.5khz spike is still there. So not sure what that is and if I can do something with this. I may try a few wings or materials to see if it's the driver, the baffle, or geometry based from the baffle. The top end is less bright. The rest is fine to start working with. But so far, this may indicate that its just going to be better to flush mount the driver on the front of the baffle. I worry about this some because my oak slabs are 1.5" thick (36mm) and so if I mount this from behind, it will have a 36mm waveguide essentially and likely have really gnarly peaks and phase flipping and stuff just from past experience doing that. I prefer the rear mounted look. But, it may just be better overall to flush mount on the front.
Any input appreciated.
Very best,
I have a tiny gap that I could have made a bit better here, so, will make note of that on the next prototype.
Overall, I'm ok with the look of it being front flush mounted. I prefer the look of the driver mounted from behind the baffle and no hardware to be seen.
Baffle 1 (red) mounted from behind
Baffle 2 (blue) mounted flush on the front
Separated more so we can examine them. The 3khz spike is gone. The 4.5khz spike is still there. So not sure what that is and if I can do something with this. I may try a few wings or materials to see if it's the driver, the baffle, or geometry based from the baffle. The top end is less bright. The rest is fine to start working with. But so far, this may indicate that its just going to be better to flush mount the driver on the front of the baffle. I worry about this some because my oak slabs are 1.5" thick (36mm) and so if I mount this from behind, it will have a 36mm waveguide essentially and likely have really gnarly peaks and phase flipping and stuff just from past experience doing that. I prefer the rear mounted look. But, it may just be better overall to flush mount on the front.
Any input appreciated.
Very best,
Trying another baffle just to see how bad it gets because I really like how it looks to mount a driver behind the baffle.
And a quick response look:
The 3khz and 4.2khz spikes are still there, so that has to be from the radius and depth of the cut out and flipping phases and causing that there.
So a quick look at phase relative to response, there's a 4khz phase bump. Anywhere a big dip is noted, there's a phase spike. So probably cannot fix these without heavy DSP/all pass filtering or just accept them.
Very best,
And a quick response look:
The 3khz and 4.2khz spikes are still there, so that has to be from the radius and depth of the cut out and flipping phases and causing that there.
So a quick look at phase relative to response, there's a 4khz phase bump. Anywhere a big dip is noted, there's a phase spike. So probably cannot fix these without heavy DSP/all pass filtering or just accept them.
Very best,
Next up, the 8" woofers I have are black. Hard to find colored woofers out there other than black. So, I probably will have to DIY my woofers to be a similar color to my wideband. I can't exactly match it so I'm gonna test a few different paint colors and then do a test run to see how it looks and practice. I'm no painter. But gonna have to learn.
This is a sample of the oak I will be using. Just to see how it response to polyurethane for color and saturation (satin).
Sampling paints
Using an old test woofer that doesn't matter, to try to see if I can paint a cone. I'm no painter. I expect to mess this up. Don't care about this woofer, so this is the test.
So I messed up and some tape leaked so some paint scattered. I'll use painter's tape next time and do a better job. Still, proof of concept done. I can paint these. I just need to do better on the next try. I can always brush black over any areas to tighten the lines I think.
I think the ivory / beige / cream cones will look good with the warmer darker oak.
Very best,
This is a sample of the oak I will be using. Just to see how it response to polyurethane for color and saturation (satin).
Sampling paints
Using an old test woofer that doesn't matter, to try to see if I can paint a cone. I'm no painter. I expect to mess this up. Don't care about this woofer, so this is the test.
So I messed up and some tape leaked so some paint scattered. I'll use painter's tape next time and do a better job. Still, proof of concept done. I can paint these. I just need to do better on the next try. I can always brush black over any areas to tighten the lines I think.
I think the ivory / beige / cream cones will look good with the warmer darker oak.
Very best,
Playing around with the woofers to see if I can improve them. I measured the GRS8 woofers in a sealed enclosure, then open baffle (technically a u-frame I suppose), and then partially blocked with a slot.
So to test this, I put gasket on the one open side, so I can close it with clamps and go sealed. Then open it back up and measure the same response but as an open baffle in a compact u-frame of sorts. Whatever you would call this.
Example of the slot, or partially obstructed side.
I then measured it sealed, fully open and with a slot or obstruction.
No DSP in the following, just raw sweeps.
Sealed. 60hz to 30hz has a 12~13db drop, so it's behaving as sealed clamped up.
Slot obstructed 1" and 2.25". The obvious cavity resonance is noted and at difference positions based on the slot area. But, the interesting thing is the slope below this is better and its nearly flat to 40hz naturally now. But the resonant spikes at 120~140hz range are not something I can work with in this system, so this is not an option.
Finally, fully open on the one side. Away from boundaries. No DSP. One sweep is the sub only. One sweep with the Lii wideband contributing above 200hz to see any behavior or conflicts. It's pretty flat to 50hz and starts to only drop by 2~3db at 40hz and 5~6db at 30hz. Much better. And fully open baffle still. I like this. So I think I will try some open backer boxes behind my primary baffle in these dimensions (11" x 11" x 11" is what did this).
I'll remeasure ground plane 2m and 4m in a few days when I can to confirm this first though.
Here's what the open baffle looks like when it has no framing at all, just my primary 18" baffle as the first measurements (in red) and what changes when the u-frame baffle is added to this woofer. A nice distinct change in the bandpass that matters most here, 30~50hz range. So I'll try to get better measurements to confirm, and then try some backer boxes with open sides on the back of the primary baffle on both GRS8 woofers.
Very best,
So to test this, I put gasket on the one open side, so I can close it with clamps and go sealed. Then open it back up and measure the same response but as an open baffle in a compact u-frame of sorts. Whatever you would call this.
Example of the slot, or partially obstructed side.
I then measured it sealed, fully open and with a slot or obstruction.
No DSP in the following, just raw sweeps.
Sealed. 60hz to 30hz has a 12~13db drop, so it's behaving as sealed clamped up.
Slot obstructed 1" and 2.25". The obvious cavity resonance is noted and at difference positions based on the slot area. But, the interesting thing is the slope below this is better and its nearly flat to 40hz naturally now. But the resonant spikes at 120~140hz range are not something I can work with in this system, so this is not an option.
Finally, fully open on the one side. Away from boundaries. No DSP. One sweep is the sub only. One sweep with the Lii wideband contributing above 200hz to see any behavior or conflicts. It's pretty flat to 50hz and starts to only drop by 2~3db at 40hz and 5~6db at 30hz. Much better. And fully open baffle still. I like this. So I think I will try some open backer boxes behind my primary baffle in these dimensions (11" x 11" x 11" is what did this).
I'll remeasure ground plane 2m and 4m in a few days when I can to confirm this first though.
Here's what the open baffle looks like when it has no framing at all, just my primary 18" baffle as the first measurements (in red) and what changes when the u-frame baffle is added to this woofer. A nice distinct change in the bandpass that matters most here, 30~50hz range. So I'll try to get better measurements to confirm, and then try some backer boxes with open sides on the back of the primary baffle on both GRS8 woofers.
Very best,
While you're at it perhaps try push-pull clamshell (with and without a small gap), sealed/isobaric vs OB/nude vs OB-U/openback. Like classic high-end KEF and Celestion. Wish GRS were sold in China.
It's bizarre to me that something made in China isn't for sale in China. 😵
GRS is just "great replacement speakers." A budget line from Dayton. They're just inexpensive options, though lately they're getting expensive due to tariff nonsense. Sadly.
It would be fun to test them in various configs, but for now, just trying to see what can be done with them that looks nice on my intended oak baffles and improve their response.
Very best,
I don't get it either. Specialty stores (on taobao) consider stamped basket too low-brow I guess. OTOH Taiwan brand Tangband moved production to China but not even a taobao store, just nada.
Given your setup with the "subwoofer" you might be pleasantly surprised by gapped clamshell isobaric or OB-U. I was! (You just mount another driver from the inside.)
Given your setup with the "subwoofer" you might be pleasantly surprised by gapped clamshell isobaric or OB-U. I was! (You just mount another driver from the inside.)
I'll consider for sure! Thanks!
This is essentially a wideband mounted on a baffle with integrated subwoofers essentially. Not really a WAW/FAST perhaps, but similar, just crossing much lower to sub drivers that cannot really do much above 500hz. But I vastly prefer full range towers with the subs integrated and not a separate thing. Just a preference.
Very best,
Another test this morning with foam board.
Made a backer box u-frame, basically, and put it on the baffle over the back of the driver.
Glued and taped it in place.
Pulled it out to the middle of a room and did a raw no-dsp sweep:
Dimensions are about 10" x 10" on the u-frame walls and 11" cavity depth. Final cavity resonance should be around 235hz or so and I see a spike around that area but its low. It would be higher on a firmer material I think. Overall shape is promising, getting flatter towards 30hz. I have an obvious hump at 60~70hz range. I'm not sure what this is yet. I think it's the frame that I glued to the kickstand being excited and coupled. It has a phase dip associated with it so I think its baffle sourced. My kickstand is 54" long and only attached at 3 little points on the back of the baffle. I glued the u-frame box to it just to keep it upright since its just on there with glue and tape. I'd think the hot glue was non-elastic enough to not transfer vibration. Maybe that's incorrect. But, 54" is 1.37m and 4x1.37m = 5.48m, 343/5.48m = 62.5hz and that's right in my hump... so maybe its just that coupling at the kick stand. Dunno. Next test I will not glue it to the kick stand and see if I get rid of that. Otherwise, pretty flat to 28hz now.
Very best,
Made a backer box u-frame, basically, and put it on the baffle over the back of the driver.
Glued and taped it in place.
Pulled it out to the middle of a room and did a raw no-dsp sweep:
Dimensions are about 10" x 10" on the u-frame walls and 11" cavity depth. Final cavity resonance should be around 235hz or so and I see a spike around that area but its low. It would be higher on a firmer material I think. Overall shape is promising, getting flatter towards 30hz. I have an obvious hump at 60~70hz range. I'm not sure what this is yet. I think it's the frame that I glued to the kickstand being excited and coupled. It has a phase dip associated with it so I think its baffle sourced. My kickstand is 54" long and only attached at 3 little points on the back of the baffle. I glued the u-frame box to it just to keep it upright since its just on there with glue and tape. I'd think the hot glue was non-elastic enough to not transfer vibration. Maybe that's incorrect. But, 54" is 1.37m and 4x1.37m = 5.48m, 343/5.48m = 62.5hz and that's right in my hump... so maybe its just that coupling at the kick stand. Dunno. Next test I will not glue it to the kick stand and see if I get rid of that. Otherwise, pretty flat to 28hz now.
Very best,
Ok, from the previous testing it's time for a new baffle incorporating everything from before that was positive.
So, cutting a new baffle. Similar dimensions, 18" width (because my final slabs of oak are 18" width on average), height somewhere between 50~60 inches. My oak slabs are over 70" long but I will cut them down. Placement of drivers and size of baffle really will be about placing the drivers at ear height when seated with one woofer above the wide band, so 45~60" baffle height is likely. So far I like the 50~55" range.
This time I'm doubling the baffle so I can get deeper chamfers and get an idea of the resulting response changes with all drivers mounted in chamfered cavities behind the baffle with a bit more depth. Similar depth to my oak slab so I know what to at least sort of expect.
After this I will cut the wholes, I think I will bring the woofers a bit closer to each other so the quarter wave distance is appropriate for about 180~200hz where I intend to hopefully cross over around from the wide band to the woofers.
I'm changing to a Lii Fast-8 instead of the F6, so an 8" wideband. Will adjust for its placement. It will not arrive for probably a month, so I will use a Visaton BG20 8" full range driver in its place in the mean time, they will have similar bass response on the baffle so I can continue tweaking there.
I'll build a scaffold out of 2x3 studs for the stand this time using joist hangers.
Instead of u-frame backer boxes as squares, I'm going to try out some 12" sonotube and cut it to about 11" length/depth and center on the back of each woofer as the u-frame backer box that is open. This way I can test the geometry, lighten the weight and then test whether or not it needs liner material to smooth out any thing other than bass.
Then install drivers and test again.
So this baffle is doubled, 1.25" thick (two 5/8th inch thick panels), 18" by 56" or so. It should have similar response as the previous due to the 18" width.
Gonna let this glue dry and the brad nails will hold it together until then and work on it tomorrow after its dry.
Very best,
So, cutting a new baffle. Similar dimensions, 18" width (because my final slabs of oak are 18" width on average), height somewhere between 50~60 inches. My oak slabs are over 70" long but I will cut them down. Placement of drivers and size of baffle really will be about placing the drivers at ear height when seated with one woofer above the wide band, so 45~60" baffle height is likely. So far I like the 50~55" range.
This time I'm doubling the baffle so I can get deeper chamfers and get an idea of the resulting response changes with all drivers mounted in chamfered cavities behind the baffle with a bit more depth. Similar depth to my oak slab so I know what to at least sort of expect.
After this I will cut the wholes, I think I will bring the woofers a bit closer to each other so the quarter wave distance is appropriate for about 180~200hz where I intend to hopefully cross over around from the wide band to the woofers.
I'm changing to a Lii Fast-8 instead of the F6, so an 8" wideband. Will adjust for its placement. It will not arrive for probably a month, so I will use a Visaton BG20 8" full range driver in its place in the mean time, they will have similar bass response on the baffle so I can continue tweaking there.
I'll build a scaffold out of 2x3 studs for the stand this time using joist hangers.
Instead of u-frame backer boxes as squares, I'm going to try out some 12" sonotube and cut it to about 11" length/depth and center on the back of each woofer as the u-frame backer box that is open. This way I can test the geometry, lighten the weight and then test whether or not it needs liner material to smooth out any thing other than bass.
Then install drivers and test again.
So this baffle is doubled, 1.25" thick (two 5/8th inch thick panels), 18" by 56" or so. It should have similar response as the previous due to the 18" width.
Gonna let this glue dry and the brad nails will hold it together until then and work on it tomorrow after its dry.
Very best,
Ok, got to work on this next baffle setup.
This time I'm swapping in the Visaton BG20 8" full range to act as my wideband until my Lii Song Fast-8 arrives (20~30 days?).
Goal this time is:
Make the similar size baffle.
Brace the baffle on the back.
Make a triangle kick stand on the back.
Sonotube backer "u-frames" instead of boxes on the woofers.
Heavy chamfer on each driver hole.
Mount drivers from behind.
Heavy sand the wideband chamfered hole (greater than 60 degree angle)
See what I get.
It's about 0930am. I'm also throwing a nice pork butt in my smoker so I can let that do its thing while I work.
First the 45 degree chamfer.
Rolling smoke.
60 degree chamfer on the central hole for the wide band.
Sanding it down with 40 grit.
Doing rabbets on the back so the drivers fit into a cubby to make it easier to hold them in place to secure down from behind.
Testing fit.
Went ahead and rounded the edges.
Baffle done. Now the support and u-frame backer tubes.
Very best,
This time I'm swapping in the Visaton BG20 8" full range to act as my wideband until my Lii Song Fast-8 arrives (20~30 days?).
Goal this time is:
Make the similar size baffle.
Brace the baffle on the back.
Make a triangle kick stand on the back.
Sonotube backer "u-frames" instead of boxes on the woofers.
Heavy chamfer on each driver hole.
Mount drivers from behind.
Heavy sand the wideband chamfered hole (greater than 60 degree angle)
See what I get.
It's about 0930am. I'm also throwing a nice pork butt in my smoker so I can let that do its thing while I work.
First the 45 degree chamfer.
Rolling smoke.
60 degree chamfer on the central hole for the wide band.
Sanding it down with 40 grit.
Doing rabbets on the back so the drivers fit into a cubby to make it easier to hold them in place to secure down from behind.
Testing fit.
Went ahead and rounded the edges.
Baffle done. Now the support and u-frame backer tubes.
Very best,
Continuing with the kick stand and the backer u-frame tubes.
I'm using 2x3's (1.5" x 2.5") studs for the bracing and framing for the stand.
Pocket jig being used for lots of pocket screws to hold it all together nicely.
Glue, clamp, pocket screw.
The entire back is now framed, serves as slightly wider baffle and a bit of bracing and easy attachment points for the stand.
Going to use 22.5 degree angles for the kick stand triangle.
Kick stand triangle 1, doing the next.
22.5 degree kick stand.
Glued, clamped, screwed in.
Next the sonotube. 12" (give or take 1") diameter. I'm using a 11" length on all of it.
Dry fitting.
Hot glue.
Both tubes in place. Effectively u-frames with a diameter of 12" and length of 11".
Let's look at the completed baffle.
Very best,
I'm using 2x3's (1.5" x 2.5") studs for the bracing and framing for the stand.
Pocket jig being used for lots of pocket screws to hold it all together nicely.
Glue, clamp, pocket screw.
The entire back is now framed, serves as slightly wider baffle and a bit of bracing and easy attachment points for the stand.
Going to use 22.5 degree angles for the kick stand triangle.
Kick stand triangle 1, doing the next.
22.5 degree kick stand.
Glued, clamped, screwed in.
Next the sonotube. 12" (give or take 1") diameter. I'm using a 11" length on all of it.
Dry fitting.
Hot glue.
Both tubes in place. Effectively u-frames with a diameter of 12" and length of 11".
Let's look at the completed baffle.
Very best,
Now to install drivers.
I'm subbing in the Visaton BG20 8" wideband until my Lii Fast-8 arrives.
I'm securing with short wood screws using stacks of washers to pinch the drivers into their rabbet holes. This way I have material away from the thin part of the chamfer on the other side to avoid any break throughs.
Same thing on the woofers.
A final view of the completed system before we test it out.
Very best,
I'm subbing in the Visaton BG20 8" wideband until my Lii Fast-8 arrives.
I'm securing with short wood screws using stacks of washers to pinch the drivers into their rabbet holes. This way I have material away from the thin part of the chamfer on the other side to avoid any break throughs.
Same thing on the woofers.
A final view of the completed system before we test it out.
Very best,
Testing time.
I did some raw sweeps and then went into the DSP to address a few things. The larger chamfered wideband hole has 2 spikes as expected, lower frequency than before since the dimensions are larger for the hole. Notching them out. Shelving up bass a bit to roll off after that.
RAW sweep of the 8" woofers in their backer open u-frame tubes. Flat to 35hz pretty much. Naturally, with no DSP. The cavity resonance is in the 230hz+ range and noted. They will be rolled down with a low pass around 200hz anyways.
Super happy with the bass response being naturally flat to 35hz like this. This was in a room not near a wall, just in the middle of the room. It will look worse when I get it outside to do a 2~4 meter ground plane measurement. But, it's great so far. Plenty of room to work with.
So then to the DSP.
The woofers get some high pass and low pass and a little shelving to give me a little more back towards 30~35hz range.
Here's the wideband and the woofers response and how I'm crossing them just under 200hz.
Sitting on this response currently. Good enough to listen to it for a while and see what I think. Will do more tweaking another day, for now, time to just kick back and listen and take notes on what to try or tweak next.
Very best,
I did some raw sweeps and then went into the DSP to address a few things. The larger chamfered wideband hole has 2 spikes as expected, lower frequency than before since the dimensions are larger for the hole. Notching them out. Shelving up bass a bit to roll off after that.
RAW sweep of the 8" woofers in their backer open u-frame tubes. Flat to 35hz pretty much. Naturally, with no DSP. The cavity resonance is in the 230hz+ range and noted. They will be rolled down with a low pass around 200hz anyways.
Super happy with the bass response being naturally flat to 35hz like this. This was in a room not near a wall, just in the middle of the room. It will look worse when I get it outside to do a 2~4 meter ground plane measurement. But, it's great so far. Plenty of room to work with.
So then to the DSP.
The woofers get some high pass and low pass and a little shelving to give me a little more back towards 30~35hz range.
Here's the wideband and the woofers response and how I'm crossing them just under 200hz.
Sitting on this response currently. Good enough to listen to it for a while and see what I think. Will do more tweaking another day, for now, time to just kick back and listen and take notes on what to try or tweak next.
Very best,
Ok, took the prototype outside to get some better measurements so I'm not chasing white rabbits down holes before I move on to the final iteration of the baffle.
I did a couple of measurements of the woofers and the wideband, separately, with no DSP or filters or anything, just raw measurements outside. Some of it ground plane, some of it semi-ground plane because I stood it up to see differences.
GRS8 woofers, laying on its side, ground plane, 2 meters. I did 3db levels increase just to see behavior and compression behavior and to look at any differences on the waterfall for structural issues (ridges ringing out, etc).
Standing upright, 2 meters, front output vs rear output (rear output is the blue/purple).
On their side, on axis vs off axis of the woofers. We see they're still behaving as a dipole, cancellation is pretty solid even at just 2 meters when 90 degree off axis well into bass.
Now standing upright, on and off axis of the woofers.
The usable bandpass of the GRS8 woofers, 20hz to 200hz (though I only care about 30hz to 200hz let's say). No smoothing. 2 meters. 100hz to 50hz is 95db to 103db (8db delta). 80hz to 40hz is 101db to 92db (9db delta), 60hz to 30hz is 97db to 87db (10db delta). 40hz to 20hz is 92db to 79db (13db delta). So my roll is pretty good, better than sealed roll off. Despite still behaving as a dipole off axis. Those u-tubes on the back are so helpful.
Waterfall just to examine it at 1000ms to see any ridges, ringing, etc. So far looks ok.
BG20 wide band gated, 2 meters, front vs rear. It's wonky as expected, but it casually gets to 300hz without rolling off hard which is all I really care to see from it. This is not my final use driver, just a place holder for now.
Finally some on vs off axis results with the wideband. It heavily drops as expected.
With that, I'm happy with the woofers and u-tube/frame behind them. The bass is fine. It will lift up to 30~35hz in a room near a boundary and still cancel nicely off axis so its less loud in my kitchen from the living room. That was the goal anyways.
This means I can move forward on my actual final baffle and start working my oak slabs to prepare them for the drivers.
Waiting to receive the Lii Song Fast-8's, hopefully soon.
Very best,
I did a couple of measurements of the woofers and the wideband, separately, with no DSP or filters or anything, just raw measurements outside. Some of it ground plane, some of it semi-ground plane because I stood it up to see differences.
GRS8 woofers, laying on its side, ground plane, 2 meters. I did 3db levels increase just to see behavior and compression behavior and to look at any differences on the waterfall for structural issues (ridges ringing out, etc).
Standing upright, 2 meters, front output vs rear output (rear output is the blue/purple).
On their side, on axis vs off axis of the woofers. We see they're still behaving as a dipole, cancellation is pretty solid even at just 2 meters when 90 degree off axis well into bass.
Now standing upright, on and off axis of the woofers.
The usable bandpass of the GRS8 woofers, 20hz to 200hz (though I only care about 30hz to 200hz let's say). No smoothing. 2 meters. 100hz to 50hz is 95db to 103db (8db delta). 80hz to 40hz is 101db to 92db (9db delta), 60hz to 30hz is 97db to 87db (10db delta). 40hz to 20hz is 92db to 79db (13db delta). So my roll is pretty good, better than sealed roll off. Despite still behaving as a dipole off axis. Those u-tubes on the back are so helpful.
Waterfall just to examine it at 1000ms to see any ridges, ringing, etc. So far looks ok.
BG20 wide band gated, 2 meters, front vs rear. It's wonky as expected, but it casually gets to 300hz without rolling off hard which is all I really care to see from it. This is not my final use driver, just a place holder for now.
Finally some on vs off axis results with the wideband. It heavily drops as expected.
With that, I'm happy with the woofers and u-tube/frame behind them. The bass is fine. It will lift up to 30~35hz in a room near a boundary and still cancel nicely off axis so its less loud in my kitchen from the living room. That was the goal anyways.
This means I can move forward on my actual final baffle and start working my oak slabs to prepare them for the drivers.
Waiting to receive the Lii Song Fast-8's, hopefully soon.
Very best,