You modeled the 4FE35 for me in post #2297 PG. 230 of this topic.This would be a 4 ohm load for the amplifier.
I guess that's where I got confused. Post 1156, page 116, the 4FE32 was simmed for a .62x box and the 4FE35 was simmed for a .57x box. Two, 8 ohm drivers per box for a 4 ohm load.
Either way, I will try one size or both to see which sound better. I also want to try both wood and foam. I'm hoping wood sounds as good as the foam because I think I can get a better wife approved finish with wood. I'll probably try something in the 1/4" thickness range. This build will happen after I finish my end tables with dual opposed 12's.
Thanks to all who have contributed to this thread. I've probably read it twice now, lol.
Either way, I will try one size or both to see which sound better. I also want to try both wood and foam. I'm hoping wood sounds as good as the foam because I think I can get a better wife approved finish with wood. I'll probably try something in the 1/4" thickness range. This build will happen after I finish my end tables with dual opposed 12's.
Thanks to all who have contributed to this thread. I've probably read it twice now, lol.
Well, finally got around to starting on a pair of foamcore speakers. Doing the vifa in a pair of the 0.4x. The only boards I could find that weren't mangled were black, and a single sheet of white, so black it is. Cutting went pretty easy, but there sure is a bit of a learning curve getting the whole thing folded and glued, and the lo-temp hot glue gun we have didn't help things... They are glued and drying as we speak.
As you can see my son couldn't resist being right there while I was doing it
As you can see my son couldn't resist being right there while I was doing it
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You gotta get to them before their mothers put other ideas in their heads!
Black looks nice! I also had a little helper making mine at the kitchen table She gave up after burning herself on the glue gun a couple of times and decided that drawing was more for her (shes 6 by the way, i wouldnt let a 3 year old hold the glue gun!).
They're great for the kids room too, they can color them before you put in the drivers Another point for foamcore...
Black looks nice! I also had a little helper making mine at the kitchen table
She gave up after burning herself on the glue gun a couple of times and decided that drawing was more for her (shes 6 by the way, i wouldnt let a 3 year old hold the glue gun!). They're great for the kids room too, they can color them before you put in the drivers
Another point for foamcore...you gotta get to them before their mothers but other thoughs in their heads
Black looks nice! I also had a little helper making mine at the kitchen table She gave up after burning herself on the glue gun a couple of times and decided that drawing was more for her (shes 6 by the way, i wouldnt let a 3 year old hold the glue gun!).
They're great for the kids room too, they can color them before you put in the drivers Another point for foamcore...
Black looks nice! I also had a little helper making mine at the kitchen table
She gave up after burning herself on the glue gun a couple of times and decided that drawing was more for her (shes 6 by the way, i wouldnt let a 3 year old hold the glue gun!). They're great for the kids room too, they can color them before you put in the drivers
Another point for foamcore...
...or can we even consider laminating thin outer plywood etc with a foamcore inner skin?
That thought has crossed my mind too. How the thicker wall will affect the sound is an unknown. I've also thought about using 3mm Birch plywood or even Liteply (poplar plywood used in model airplanes) for the construction. MDF would be first prize, though - but only if the sound is not affected.
It's been a long time since I read through this thread but better sound was, I think, one of the reasons I used foam. If I recall correctly some were unhappy with the sound from their mdf and/or wood assemblies. I have a large stack of mdf here and after the falling mattress accident, I've been considering it so I'm kind of curious about this too. If I'm motivated this weekend I could build both and have a listen when their ready. Doubtful I'm motivated.
Liteply was successful I think as it resonates much like a tone wood panel on a guitar. I think laminating liteply with foam core would work fine. Some damping provided by the foam is good. As always, bracing internally should be done so it doesn't vibrate like a drum membrane. MDF and plywood have been used with mixed results. I think Francisco built a beautiful one from ply and painted all white. He did not say anything about poor sound quality. But I have heard from 3 others that plywood or MDF sounded bad.
FWIW a co-worker did a 0.41x pair with the TC9 in 1/4" BB ply and they sound fantastic, but he said it took a ton of trial and error with stuffing, and he lined the rear of the karlson aperture with felt, as well as used carpet padding on the rear wall just behind the driver. He likes them so much he wants to do a set of 0.53x in 1/2" ply next with dual TC9s for use at home. He runs them on his desk at work with a Tubelab Simple SE running 6V6 triode outputs, and it's a wonderful and affordable setup for killer quality all around. I have to say that with them running in an office environment it's hard to actually tell where they are until you know where to look.
I haven't finished mine yet (I spent my day off yesterday putting an engine in my car, synchronizing carburetors, then date night) but if I like mine I'm thinking of grabbing a quad of the TG9 that are on special at madisound to do up a pair of the 0.53x.
From the other thread-
Vifa TG9FD10-04 3.5" Full Range
Do you think that the TG9 would be a drop-in substitute for the TC9 in the 0.53x dual version? It seems that they should be... Or do you think using a PA130 or two TC9 per side would be better?
I haven't finished mine yet (I spent my day off yesterday putting an engine in my car, synchronizing carburetors, then date night) but if I like mine I'm thinking of grabbing a quad of the TG9 that are on special at madisound to do up a pair of the 0.53x.
From the other thread-
Vifa TG9FD10-04 3.5" Full Range
Do you think that the TG9 would be a drop-in substitute for the TC9 in the 0.53x dual version? It seems that they should be... Or do you think using a PA130 or two TC9 per side would be better?
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Thanks for the feedback on wooden mini 0.4x Karlsonators that sound great. It looks like lots of padding on back chamber is needed to get rid of boxy sound and felt on inside of the K aperture too. The foam core probably absorbs some of the sound and is not a good reflector like wood is.
For a dual TC9FD in 0.53x, you cannot use the 4ohm TG9FD as that would be a 2ohm load (unless you have a 2ohm capable amp). Also, the 4ohm TG9FD appears to be substantially different in frequency response than either the 8ohm TG9FD or the TC9FD. You would be better off getting the $12 TC9FD and getting four of them. Alternatively, if you want super high sensitivity, do what Skyar did and get a pair of Faital Pro 3FE25 in 16ohms (91dB ea) and wire in parallel for a 97dB sensitive 8ohm speaker. You are now into the ultra high sensitivity speaker realm of $400 to $600 Lowthers and similar high end drivers (which are not anywhere nearly as flat measuring).
My recommendation if you want ultimate sound, get the dual 3FE25-16's. For fun budget sound, get the PA130-8. For budget smooth sound at 91dB sensitivity and 4ohms, get the dual TC9FD.
For a dual TC9FD in 0.53x, you cannot use the 4ohm TG9FD as that would be a 2ohm load (unless you have a 2ohm capable amp). Also, the 4ohm TG9FD appears to be substantially different in frequency response than either the 8ohm TG9FD or the TC9FD. You would be better off getting the $12 TC9FD and getting four of them. Alternatively, if you want super high sensitivity, do what Skyar did and get a pair of Faital Pro 3FE25 in 16ohms (91dB ea) and wire in parallel for a 97dB sensitive 8ohm speaker. You are now into the ultra high sensitivity speaker realm of $400 to $600 Lowthers and similar high end drivers (which are not anywhere nearly as flat measuring).
My recommendation if you want ultimate sound, get the dual 3FE25-16's. For fun budget sound, get the PA130-8. For budget smooth sound at 91dB sensitivity and 4ohms, get the dual TC9FD.
Would there be some "gotcha" I'm not seeing that would prevent me from using the 4 ohm TG9 in series for 8 ohm total? Or do they just have improper characteristics for karlsonators? I can work with a 4 or 8 (even 16, really) ohm nominal with my amplifiers, I'm a DIY tube guy and can make do with most setups with amp selection or output transformer tap selection.
If you don't think they are worth the effort/money I'll stick to the TC9, it's just tempting based on the posted measurements and price to grab a few 4 ohm TG9 to try if they can work well, maybe even just for 0.41x karlsonators later on.
Those 3FE25 look very tempting, and would probably be a fantastic choice, a bit out of budget currently, but definitely worth keeping in mind and thinking about. Especially since I have a thing for super low THD flea power experiments lately, I've got a 6SN7GTA AB2 (Yes, AB2, grids fed positive voltage via mosfet followers for extra oomph at high signal level) that will do an honest 2W at .01% THD, although it will make tube purists insane
It would be sweet to have a pair of ultra-efficient foamcore speakers that are every bit as good as bigbuck speakers... Would drive the snobs crazy.
If you don't think they are worth the effort/money I'll stick to the TC9, it's just tempting based on the posted measurements and price to grab a few 4 ohm TG9 to try if they can work well, maybe even just for 0.41x karlsonators later on.
Those 3FE25 look very tempting, and would probably be a fantastic choice, a bit out of budget currently, but definitely worth keeping in mind and thinking about. Especially since I have a thing for super low THD flea power experiments lately, I've got a 6SN7GTA AB2 (Yes, AB2, grids fed positive voltage via mosfet followers for extra oomph at high signal level) that will do an honest 2W at .01% THD, although it will make tube purists insane
It would be sweet to have a pair of ultra-efficient foamcore speakers that are every bit as good as bigbuck speakers... Would drive the snobs crazy.
Dual TG9FD 4ohms in series is 8ohms but sensitivity takes a hit so it requires more voltage. However, if driving with 8ohms output transformers and tube amp it may work just fine. The frequency response should be fine - I was more concerned about going 8ohms and 80dB at 2.83v.
You could go do an ultimate quad x 4ohm TG9FD (wired series parallel) in a diamond pattern on a 1.0x scale Karlsonator for 91dB sensitive speaker that probably goes to 42Hz.
Let me run a sim of the quad driver Karlsonator to defermine exact scaling. It might be 0.75x or something like that.
You could go do an ultimate quad x 4ohm TG9FD (wired series parallel) in a diamond pattern on a 1.0x scale Karlsonator for 91dB sensitive speaker that probably goes to 42Hz.
Let me run a sim of the quad driver Karlsonator to defermine exact scaling. It might be 0.75x or something like that.
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Quad TG9FD-04 Karlsonator
I ran some quick sims and it looks like a quad TG9FD could be really interesting. Not the deepest bass extension, but is a bonafide 96dB at 2.83v speaker with about 75Hz tuning (62Hz F3) for rich full bass. This could work very well for fleawatt system. Max power is only about 10.5wrms (6.5vrms) before hitting xmax and gets about 104dB.
So dimensions ended up at a squat looking wide format box 0.52x scale in Height and Depth and 0.78x in Width. This works out to be a Square format box at 16in tall x 16in wide x 9in deep. Not the most attractive aspect ratio, but can be nice if you don't mind a "sound cube" concept.
Here is frequency response:
Here is Impedance:
Here is Cone Displacement:
Here is Cone Displacement at xmax limtied max power of 10.5wrms (thermal max power is 5w x 4 or 20wrms):
At $9ea x 4 = $36 and not a bad deal for a 96dB sensitive speaker.
For normal music listening levels of 90dB at 1m, takes 1.5vrms and cone displacement max is only 0.8mm, so it is well within linear travel limts so will sound very clear and low distortion. With 14dB dynamic reserve from 90dB is a good thing. Should be a fine sounding quite compact speaker.
I ran some quick sims and it looks like a quad TG9FD could be really interesting. Not the deepest bass extension, but is a bonafide 96dB at 2.83v speaker with about 75Hz tuning (62Hz F3) for rich full bass. This could work very well for fleawatt system. Max power is only about 10.5wrms (6.5vrms) before hitting xmax and gets about 104dB.
So dimensions ended up at a squat looking wide format box 0.52x scale in Height and Depth and 0.78x in Width. This works out to be a Square format box at 16in tall x 16in wide x 9in deep. Not the most attractive aspect ratio, but can be nice if you don't mind a "sound cube" concept.
Here is frequency response:
Here is Impedance:
Here is Cone Displacement:
Here is Cone Displacement at xmax limtied max power of 10.5wrms (thermal max power is 5w x 4 or 20wrms):
At $9ea x 4 = $36 and not a bad deal for a 96dB sensitive speaker.
For normal music listening levels of 90dB at 1m, takes 1.5vrms and cone displacement max is only 0.8mm, so it is well within linear travel limts so will sound very clear and low distortion. With 14dB dynamic reserve from 90dB is a good thing. Should be a fine sounding quite compact speaker.
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I'm a novice willing to patiently and cluelessly follow instructions at the mercy of other's expertise but I think the high frequency is problematic.
TG9FD 4ohm frequency response 110 - 10k
TC9FD 8ohm 100 - 20k
side note: Man this place is addictive. I want to ditch/sell my brand name gear and diy sound in four different applications. Five! Forgot the car.
TG9FD 4ohm frequency response 110 - 10k
TC9FD 8ohm 100 - 20k
side note: Man this place is addictive. I want to ditch/sell my brand name gear and diy sound in four different applications. Five! Forgot the car.