For anybody interested, it looks like Home Depot sells 1/4" plywood with some nice veneer for a pretty reasonable price (online only, ship to home) and will custom cut it for you. The reviews seem fairly positive, and they apparently are cut nicely. Red oak is $6 each, not too bad. I've been thinking of buying four of the 1/4"x24"x24" in Cedar, not too bad of a price at $8.25 a sheet, for $43.21 shipped (in my case, with tax to my area), may be a good option for some who aren't able/equipped to cut the wood themselves.
Still not too pricy, once considered. Figure a $10~$20 driver (TC9FD, FE85, 3FE25, etc) per side you're still at $60~85 a pair when using foamcore for the channels.
https://www.homedepot.com/p/Columbia-Forest-Products-1-4-in-x-2-ft-x-2-ft-PureBond-Aromatic-Cedar-Plywood-Project-Panel-Free-Custom-Cut-Available-2809/204771228
Only issue here is that one can't pick out what they want, but there's also some fun to be had figuring out how to use stuff as it comes, if you're into that sort of thing
Still not too pricy, once considered. Figure a $10~$20 driver (TC9FD, FE85, 3FE25, etc) per side you're still at $60~85 a pair when using foamcore for the channels.
https://www.homedepot.com/p/Columbia-Forest-Products-1-4-in-x-2-ft-x-2-ft-PureBond-Aromatic-Cedar-Plywood-Project-Panel-Free-Custom-Cut-Available-2809/204771228
Only issue here is that one can't pick out what they want, but there's also some fun to be had figuring out how to use stuff as it comes, if you're into that sort of thing
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That's nice stuff. Thanks for the tip.
The other thing I have noticed are hardwood faced engineered floorboards. They can be had in 5in widths perfect for 3.5in driver baffles. Cheap (free) if you can get excess cut-offs or samples. They are also interlocking so two could be glued for a 10in baffle.
There are even all vinyl synthetic wood floors with cork backing. They are very dense and probably make a great baffle.
The other thing I have noticed are hardwood faced engineered floorboards. They can be had in 5in widths perfect for 3.5in driver baffles. Cheap (free) if you can get excess cut-offs or samples. They are also interlocking so two could be glued for a 10in baffle.
There are even all vinyl synthetic wood floors with cork backing. They are very dense and probably make a great baffle.
That should fit a standard 28in x 5in deep Cornu. Note that it’s not a full range driver so may need a tweeter (super tweeter) above 8kHz. Try a small flat Nd dome with a simple circa 1uF to 4.7uF cap in parallel to main driver. Maybe add resistors to attenuate tweeter to level match. Sort of like the XKiClops. Or a small a AMT may work very nicely too.
Dayton Audio AMT Mini-8 Air Motion Transformer Tweeter 8 Ohm
Dayton Audio AMT Mini-8 Air Motion Transformer Tweeter 8 Ohm
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Thanks xrk971! Good to be back and see ur posts. I'm not married to this driver; is there a proven good one for this same size box ~28X5? I tried to read thru this thread again, but 250 pages- I fell asleeo a few times I'm 66 and don't hear too high on the freq scale anymore, maybe 13Khz is where I max out.
I'm 66 and don't hear too high on the freq scale anymore, maybe 13Khz is where I max out.
This driver also caught my eye- it's cheap too. Dayton PC105
Product Specifications
Nominal Diameter4"Power Handling (RMS)40 Watts
Power Handling (max)80 WattsImpedance4 ohms
Frequency Response80 to 15,000 HzSensitivity90.3 dB 2.83V/1m
Voice Coil Diameter1"
Thiele-Small Parameters
Resonant Frequency (Fs)81.4 HzDC Resistance (Re)3.3 ohms
Voice Coil Inductance (Le)0.32 mHMechanical Q (Qms)2.17
Electromagnetic Q (Qes)0.67Total Q (Qts)0.51
Compliance Equivalent Volume (Vas)0.13 ft.³Mechanical Compliance of Suspension (Cms)0.92 mm/N
BL Product (BL)3.3 TmDiaphragm Mass Inc. Airload (Mms)4.2g
Maximum Linear Excursion (Xmax)2 mmSurface Area of Cone (Sd)52.8 cm²
Product Specifications
Nominal Diameter4"Power Handling (RMS)40 Watts
Power Handling (max)80 WattsImpedance4 ohms
Frequency Response80 to 15,000 HzSensitivity90.3 dB 2.83V/1m
Voice Coil Diameter1"
Thiele-Small Parameters
Resonant Frequency (Fs)81.4 HzDC Resistance (Re)3.3 ohms
Voice Coil Inductance (Le)0.32 mHMechanical Q (Qms)2.17
Electromagnetic Q (Qes)0.67Total Q (Qts)0.51
Compliance Equivalent Volume (Vas)0.13 ft.³Mechanical Compliance of Suspension (Cms)0.92 mm/N
BL Product (BL)3.3 TmDiaphragm Mass Inc. Airload (Mms)4.2g
Maximum Linear Excursion (Xmax)2 mmSurface Area of Cone (Sd)52.8 cm²
Friends,
I did an experiment.
I just mixed this full range Cornu board with high class Fountek rd 1.0 Ribbon Tweeter.
Now again i added Denon Sub-Woofer, for Lowest Frequencies to add depth.
To add, some more spices, i used MiniDSP 2X4 Board with Active DSP, to leverage full benefits of Parametric EQ and Leveler to match Speakers crossover (48DB/Oct separation), and you all will be surprised with that.
I uploaded video on you tube, link is YouTube
I recorded audio-video in 24-Bit audio format but editing and uploading into Youtube, just messed up with original quality. Although quality is somehow manageable.
I need carl & xrk971 review, as this thread is only because of their most of contribution.
YouTube
This costing a lot (around 400$ + more)
I did an experiment.
I just mixed this full range Cornu board with high class Fountek rd 1.0 Ribbon Tweeter.
Now again i added Denon Sub-Woofer, for Lowest Frequencies to add depth.
To add, some more spices, i used MiniDSP 2X4 Board with Active DSP, to leverage full benefits of Parametric EQ and Leveler to match Speakers crossover (48DB/Oct separation), and you all will be surprised with that.
I uploaded video on you tube, link is YouTube
I recorded audio-video in 24-Bit audio format but editing and uploading into Youtube, just messed up with original quality. Although quality is somehow manageable.
I need carl & xrk971 review, as this thread is only because of their most of contribution.
YouTube
This costing a lot (around 400$ + more)
CIRCLE
I used full range audio labs 4" dual cone speaker as mid range.
Fountek rd 1.0 super tweeter has been used at 3500hz cutoff frequency with 48db/octave filter.
Denon sub woofer being used below 200 to 75 hz.
ACTIVE DSP IS BEING USED.
Crossover function is used through MINIDSP.
Input signal is fed through creative sound card.
Original Recording was made through 24bit recorder, but YouTube and I movie editor ruined it.
Parametric EQ was also implemented through MINIDSP.
80+80 watt rms class-d amplifier was used (TDA7498).
I used full range audio labs 4" dual cone speaker as mid range.
Fountek rd 1.0 super tweeter has been used at 3500hz cutoff frequency with 48db/octave filter.
Denon sub woofer being used below 200 to 75 hz.
ACTIVE DSP IS BEING USED.
Crossover function is used through MINIDSP.
Input signal is fed through creative sound card.
Original Recording was made through 24bit recorder, but YouTube and I movie editor ruined it.
Parametric EQ was also implemented through MINIDSP.
80+80 watt rms class-d amplifier was used (TDA7498).
Hi SDJ,
I listened again with my nice headphones (OB-1) and a SE Class A headphone amp and the sound is very good - excellent actually. Nice bass and surprising depth from a 4in driver and a Cornu. You did not mention the dimensions of the Cornu you used, or standard 28in x 5.5in deep?
I could barely make out the ribbon tweeter at the top as it is partially cropped. Anyhow, nice work. I may have to revisit the Cornu again and add maybe a small AMT or a B&G on top.
Thanks for sharing.
I listened again with my nice headphones (OB-1) and a SE Class A headphone amp and the sound is very good - excellent actually. Nice bass and surprising depth from a 4in driver and a Cornu. You did not mention the dimensions of the Cornu you used, or standard 28in x 5.5in deep?
I could barely make out the ribbon tweeter at the top as it is partially cropped. Anyhow, nice work. I may have to revisit the Cornu again and add maybe a small AMT or a B&G on top.
Thanks for sharing.
Attachments
I took advantage of the single digit temps (or less) and whipped up a couple more of these foamcore speakers. These are 28” x 4” Cornu spiral horns with Dayton PC105-4 4” drivers. Cost about $60 altogether. Used Lowe's RevolutionPly 5mm poplar plywood for the front and backs. Overall they turned out OK. There is some confusion as to what I'm hearing in the midrange on some recordings, most likely drum or percussive string sounds. I'm a big fan of the various mini Karlsonators w/TC9FD's, and have delved into high end wooden projects in the past w/Focal and ScanSpeak drivers. So it'd be nice to have clearer detail, and I may order some Tang Band W42142's to plop in these boxes. Previously I built micro Cornus (14.5” sq) w/2” drivers for my TV and they yielded outstanding results. I knew ahead of time that these are not reference monitors but should result in some big wow factor. A surprise was working with the RevolutionPly instead of all foamcore. Even tho I picked a very good specimen 4x8 out of the stack at Lowes, the material exhibited waviness and buckling, especially when attaching the second piece (back). I was simply unprepeared for that and didn't have the necessary number of small heavy weights or dozens of large clamps necessary to combat this. The first speaker came out OK but the second was a mess and had lots of large air gaps after the glue dried. Hopefully they were all near the edges so I could fill in the gaps. All four horns seem to be transmitting OK tho one was a bit weaker than the others. That said, there is no lacking of bass in these things. It was a wonderful way to fill up a subzero week. Only sliced my finger once and then took time off to build an apple pie Also threw a loaf of bread in there for some variety. Thanks to everyone who tried these and talked about their experiences especially Cal and X. I posted a YouTube with a variety of short music clips that I'm prone to listen to and one w/ vocals that we recorded here locally with people I regularly work with. It was recorded on a portable Tascam that has built in X-Y mics. Everything on the recorder is flat but it yielded a bassier sound than what was experienced in the listening room. There is very minor adjustment to the eq in my computer, maybe 3 bands and nothing changed more than 2dB. So these speakers turned out surprisingly flat.
YouTube
Also threw a loaf of bread in there for some variety. Thanks to everyone who tried these and talked about their experiences especially Cal and X. I posted a YouTube with a variety of short music clips that I'm prone to listen to and one w/ vocals that we recorded here locally with people I regularly work with. It was recorded on a portable Tascam that has built in X-Y mics. Everything on the recorder is flat but it yielded a bassier sound than what was experienced in the listening room. There is very minor adjustment to the eq in my computer, maybe 3 bands and nothing changed more than 2dB. So these speakers turned out surprisingly flat.YouTube
Attachments
Hi Bonjonno,
I loved your video! Nice production and what a great way to share the journey of making the Cornu's. I see the Karlsonator's have a big role in your sound system too. Your Cornu's sound excellent - I have never heard the new Dayton's before so it looks like they might be a good choice for a lot of projects. You are a baker too! Winter is a great time to make bread and nothing makes the house smell better. It looks like you really made this on your kitchen counter.
Thanks for sharing,
X
Qts of 0.51 is a nice figure for a $10 driver. This would be great for a MLTL or in a Karlsonator too.
https://www.parts-express.com/pedocs/specs/295-158--dayton-audio-pc105-4-specifications.pdf
I loved your video! Nice production and what a great way to share the journey of making the Cornu's. I see the Karlsonator's have a big role in your sound system too. Your Cornu's sound excellent - I have never heard the new Dayton's before so it looks like they might be a good choice for a lot of projects. You are a baker too! Winter is a great time to make bread and nothing makes the house smell better. It looks like you really made this on your kitchen counter.
Thanks for sharing,
X
Qts of 0.51 is a nice figure for a $10 driver. This would be great for a MLTL or in a Karlsonator too.
https://www.parts-express.com/pedocs/specs/295-158--dayton-audio-pc105-4-specifications.pdf
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DOH! I subscribed to this thread but didn't get any notification you guys replied. Thanks X for ur kind words, you have been a total inspiration for these projects. Down to one piece of apple pie I have connected the 28" Cornu and XKiClops together and have listened to the combo for 12 hours or so and they sound great together. It could be that the Cornus are breaking in a bit and smoothing out a little. PJN thanks for the tip. In fact, I forgot to stuff b4 gluing on the back. Forgot twice!! One of the perks of getting old. I use dacron from old pillows because it's usually on hand and goes a long way. So, I pushed some into the two channels of the throat as far as I could, stuffed the speaker box- did this b4 first screwing the driver on, and put two good fistfuls in each horn mouth to taste while the music was playing. The big wads in the horn mouths really cured the boominess. It's cool you suggested exactly what I already did, affirmation that it's a good move.
I have connected the 28" Cornu and XKiClops together and have listened to the combo for 12 hours or so and they sound great together. It could be that the Cornus are breaking in a bit and smoothing out a little. PJN thanks for the tip. In fact, I forgot to stuff b4 gluing on the back. Forgot twice!! One of the perks of getting old. I use dacron from old pillows because it's usually on hand and goes a long way. So, I pushed some into the two channels of the throat as far as I could, stuffed the speaker box- did this b4 first screwing the driver on, and put two good fistfuls in each horn mouth to taste while the music was playing. The big wads in the horn mouths really cured the boominess. It's cool you suggested exactly what I already did, affirmation that it's a good move.
Damping
Hey guys,
I even had to use some damping material in my Monster Spiral Horn to reduce a weak peak at ~ 75 Hz - although the horn is only operated from about 30 Hz to about 60 Hz.
A 20cm ball of rather tightly pressed and laced BAF wool just behind the two drivers was enough.
Careful attenuation of horns with broadband speakers is therefore even more important.
LG Doc
Hey guys,
I even had to use some damping material in my Monster Spiral Horn to reduce a weak peak at ~ 75 Hz - although the horn is only operated from about 30 Hz to about 60 Hz.
A 20cm ball of rather tightly pressed and laced BAF wool just behind the two drivers was enough.
Careful attenuation of horns with broadband speakers is therefore even more important.
LG Doc
Horny Cornu's
I've been grooving on a Cornu Plus setup for the last few months. The 'plus' is that I added a pair of XKiClops (XKi's w/ tweeters)speakers to fill out the midrange and highs. The Cornus really filled up the room with a nice horn sound, but wasn't very bright with the driver I chose (Dayton PC105). Last night I was eating dinner and my playlist ran out; the ensuing silence was interesting and I had an idea. Build a small horn for the 4" driver. The purists are going to hate this part, but I cut some trapezoids out of foamcore and glued this thing up w/o any idea about angles and sizes except what I pictured in my head. As soon as I held the horn up to the driver I could hear the sound "focus." So I taped the horns on temporarily and started listening. There is an abundance of mids now that matches better the rest of the sound. I listen to alot of jazz, acoustic and electric. The horns sound magnificent and so does acoustic piano. Everything is in ur face now. Drums slam and kick drum is much punchier. About the only minus is that staging is not enormous like it used to be. Spatially it's flatter effect.
I've been grooving on a Cornu Plus setup for the last few months. The 'plus' is that I added a pair of XKiClops (XKi's w/ tweeters)speakers to fill out the midrange and highs. The Cornus really filled up the room with a nice horn sound, but wasn't very bright with the driver I chose (Dayton PC105). Last night I was eating dinner and my playlist ran out; the ensuing silence was interesting and I had an idea. Build a small horn for the 4" driver. The purists are going to hate this part, but I cut some trapezoids out of foamcore and glued this thing up w/o any idea about angles and sizes except what I pictured in my head. As soon as I held the horn up to the driver I could hear the sound "focus." So I taped the horns on temporarily and started listening. There is an abundance of mids now that matches better the rest of the sound. I listen to alot of jazz, acoustic and electric. The horns sound magnificent and so does acoustic piano. Everything is in ur face now. Drums slam and kick drum is much punchier. About the only minus is that staging is not enormous like it used to be. Spatially it's flatter effect.
Attachments
Nice work Bonjonno!
If you look in HornResp software, it can generate a tractrix profile template for you. It will sound much better - amazing actually.
Tractrix Midbass Fronthorns – Volvotreter Homepage
I have also used a spreadsheet that Volvotreter has provided on his website to make some nice tractrix horns.
If you look in HornResp software, it can generate a tractrix profile template for you. It will sound much better - amazing actually.
Tractrix Midbass Fronthorns – Volvotreter Homepage
I have also used a spreadsheet that Volvotreter has provided on his website to make some nice tractrix horns.
