The Karlsonators' imaging is absolutely excellent. It is so good, I think I'm spoiled for life. I'm afraid that IF (not when) I ever "upgrade" to bigger speakers, I'll lose the fantastic imaging of my 0.53x dual 3FE25-16 Karlsonators. I have yet to listen to speakers that come even close in that department! But I imagine it also has to do with the amp you power them with. I'm using an ACA with B1 buffer/pre and H2 V1. Not the most powerful setup, but boy, is the imaging good!
Edit: Nearly forgot... To get good imaging, I use "toe in" or whatever it's called. The certrelines of the speakers have to cross about two feet in front of your face for best results..
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Edit: Nearly forgot... To get good imaging, I use "toe in" or whatever it's called. The certrelines of the speakers have to cross about two feet in front of your face for best results..
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I made the foamcore K's!
I had great fun building them, based on the brilliant and almost idiot-proof Muddjester plans.
Notes from an idiot:
I didn't "buy" (steal from work) enough foamcore. Ran out, and had to actually BUY some.
I riffed off the measurements a bit, and rounding errors add up. Also my decision to step the edge joins (a very basic rebate joint) lead to a lot of head-scratching, and a few mis-cuts.
Hot glue cools fast. It was a fight to get all the beads laid in time. The first few side laminates I did in hot glue, but couldn't squeeze them tightly together. (I bet there's all sorts of resonant hell going on with those). The rest I did with spray contact adhesive which worked fine.
I squidged wadding into the speakers as directed by one or other of the threads here, but ran out of that too. Probably should have got more before I glued the speakers up.
I used a big pack of eBay magic sponges I found at home, and somewhat haphazardly popped them in up the back of the enclosure, leaving some for the cheeks on the front as suggested by Lord xrk. Ran out of these also. Speakers use a lot of stuff! I've never built speakers before, in case you couldn't tell.
I pondered how to access the nearly built speakers in order to finesse the amount of dampening but then glued them up anyway. Wine was involved. I can always make more.
They're really solid! What a great structural design, thanks xrk.
I'm loving how they sound. Actually proper bass, and real depth at low volumes. They sound like they'll go loud as well from my little SET amp. I only have one layer of foam on the grille at the moment (oh HI, work stationery cupboard!!), which probably accounts for a bit more resonance than I'd like at the moment. And the grilles are blu-tac'd on.
I'll continue fiddling with them for a few weeks, then think about making some permanent versions for home. I'm not wedded to wood- Has anyone tried foamex? We've been CNC-ing things out of it at work and it's an impressive material, I can imagine interesting for speakers.
Thanks again to xrk for enticing me onto this bandwagon..!
(yes I know the pictures are sideways. No I can't remember how to fix it)
I had great fun building them, based on the brilliant and almost idiot-proof Muddjester plans.
Notes from an idiot:
I didn't "buy" (steal from work) enough foamcore. Ran out, and had to actually BUY some.
I riffed off the measurements a bit, and rounding errors add up. Also my decision to step the edge joins (a very basic rebate joint) lead to a lot of head-scratching, and a few mis-cuts.
Hot glue cools fast. It was a fight to get all the beads laid in time. The first few side laminates I did in hot glue, but couldn't squeeze them tightly together. (I bet there's all sorts of resonant hell going on with those). The rest I did with spray contact adhesive which worked fine.
I squidged wadding into the speakers as directed by one or other of the threads here, but ran out of that too. Probably should have got more before I glued the speakers up.
I used a big pack of eBay magic sponges I found at home, and somewhat haphazardly popped them in up the back of the enclosure, leaving some for the cheeks on the front as suggested by Lord xrk. Ran out of these also. Speakers use a lot of stuff! I've never built speakers before, in case you couldn't tell.
I pondered how to access the nearly built speakers in order to finesse the amount of dampening but then glued them up anyway. Wine was involved. I can always make more.
They're really solid! What a great structural design, thanks xrk.
I'm loving how they sound. Actually proper bass, and real depth at low volumes. They sound like they'll go loud as well from my little SET amp. I only have one layer of foam on the grille at the moment (oh HI, work stationery cupboard!!), which probably accounts for a bit more resonance than I'd like at the moment. And the grilles are blu-tac'd on.
I'll continue fiddling with them for a few weeks, then think about making some permanent versions for home. I'm not wedded to wood- Has anyone tried foamex? We've been CNC-ing things out of it at work and it's an impressive material, I can imagine interesting for speakers.
Thanks again to xrk for enticing me onto this bandwagon..!
(yes I know the pictures are sideways. No I can't remember how to fix it)
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Hi Jodyone,
Very nice work! They look great. I wouldn’t have known they were your first foam core speakers as you made it look clean and neat. The second final side wall has to be glued with a slow drying glue. Hot melt hardens too fast. If they made one that took 2 minutes to harden we would have something.
I did not catch what drivers you are using? Or you asked at one point and I forgot. They look nice.
Very nice work! They look great. I wouldn’t have known they were your first foam core speakers as you made it look clean and neat. The second final side wall has to be glued with a slow drying glue. Hot melt hardens too fast. If they made one that took 2 minutes to harden we would have something.
I did not catch what drivers you are using? Or you asked at one point and I forgot. They look nice.
Thanks xrk. I managed to just outrace the hot glue on the final side wall, so I'm confident it's sealed internally, but could have been neater.
Drivers are Realistic 40-1311, NOS from the 70's. Nice chunky cast ali baskets. They're apparently a version of Fostex FX120's, according to the internet. I really enjoyed them in some quick open baffles I made, and I like them more now they have bass.
Drivers are Realistic 40-1311, NOS from the 70's. Nice chunky cast ali baskets. They're apparently a version of Fostex FX120's, according to the internet. I really enjoyed them in some quick open baffles I made, and I like them more now they have bass.
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Hi Folks,
I was listening to the 0.53x with dual 3FE25-16’s last night on a stand out in the open. The imaging was incredible but I noticed the tonal balance was vastly improved with a simple baffle step compensation (BSC) filter consisting of a 0.68mH inductor in parallel with a 4.7ohm resistor. I tried both steel core and air core and found no difference in sound quality on the mids and highs. But the steel core has lower DCR so better bass, plus they cost less. A very worthwhile mod of you are wondering - it really brings up the bass and makes the speaker feel like it’s reaching closer to 55Hz now, vs 70Hz or 80Hz as before. You lose a tad in sensitivity of the top end but worth it in my opinion. Give it a try, cheap as mods go. Under $11 mod.
1mH can work too - have a listen yourself. Easy to unwind about 20 loops to make it 0.68mH (use an LCR to check).
Dayton Audio 1.0mH 18 AWG I Core Inductor Crossover Coil
https://www.parts-express.com/Dayton-Audio-DNR-4.7-4.7-Ohm-10W-Precision-Audio-Grade-Resis-004-4.7
I was listening to the 0.53x with dual 3FE25-16’s last night on a stand out in the open. The imaging was incredible but I noticed the tonal balance was vastly improved with a simple baffle step compensation (BSC) filter consisting of a 0.68mH inductor in parallel with a 4.7ohm resistor. I tried both steel core and air core and found no difference in sound quality on the mids and highs. But the steel core has lower DCR so better bass, plus they cost less. A very worthwhile mod of you are wondering - it really brings up the bass and makes the speaker feel like it’s reaching closer to 55Hz now, vs 70Hz or 80Hz as before. You lose a tad in sensitivity of the top end but worth it in my opinion. Give it a try, cheap as mods go. Under $11 mod.
1mH can work too - have a listen yourself. Easy to unwind about 20 loops to make it 0.68mH (use an LCR to check).
Dayton Audio 1.0mH 18 AWG I Core Inductor Crossover Coil
https://www.parts-express.com/Dayton-Audio-DNR-4.7-4.7-Ohm-10W-Precision-Audio-Grade-Resis-004-4.7
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Beautiful job Jodyone! I've made much sloppier versions of a lot of XRK's designs and they have all been satisfying. The first attempt were Mini K's with TC9's which I still use on one of my computers. I audition all the weekly Spotify recommendations on them and they never seem lacking. On another rig at the same location I monitor on much larger Focals with 7" woofer and 1" titanium tweeter; of course they sound larger but both systems sound fine to my musician ears. In my main room I built Trynergy's out of foam and they are just like being there.
Attachments
I think Jantzen inductors is a good source in EU. Air core ones would work fine. Something like 18ga 0.68mH to 1mH.
Air Core Wire Coil - Jantzen-audio.com
Air Core Wire Coil - Jantzen-audio.com
Inductor types for crossovers
This is a little off topic; my apologies.
is there some reason that crossover inductors are often air-core?
How would the listed Dayton ferrite-core inductor differ?
And then further, how would a toroidal inductor differ?
I suppose I can do my own experiments.
*sigh*
Kind regards,
Drew
This is a little off topic; my apologies.
is there some reason that crossover inductors are often air-core?
How would the listed Dayton ferrite-core inductor differ?
And then further, how would a toroidal inductor differ?
I suppose I can do my own experiments.
*sigh*
Kind regards,
Drew
Air core inductors will not suffer from saturation and will have less distortion. Although the flat plates iron inductors work quite well for my purposes. Toroidal core will contain the magnetic field more but can saturate easier from DC offset. Air core will be larger and need significantly more wire so have higher DCR. For use with woofers where keeping DCR low is important, the iron core makes more sense.
But I use microwave oven transformers for audio inductors as a choke load on a single ended Class A amp and they sound fine and measure well. For example:
LuFo Amp - 39w SE Class A from 28v Rail
The may saturate sooner from higher DC loads at low bass frequencies compared to audio-specific inductors.
But I use microwave oven transformers for audio inductors as a choke load on a single ended Class A amp and they sound fine and measure well. For example:
LuFo Amp - 39w SE Class A from 28v Rail
The may saturate sooner from higher DC loads at low bass frequencies compared to audio-specific inductors.
3fe 25 in a .4x
Hi all,
I've been following this thread for a while and so I thought I must try to make one (pair).
I'm converting a van to camper at the moment and a .4x Karlsonator should be light and tidy enough to fit in somewhere.
I've already bought a pair of 3fe 25s, a Sure Electronics AA-JA 32151 amp module, and three sheets of 10mm foamcore. I'm just wondering will I need any particular type of damping in the box?
Hi all,
I've been following this thread for a while and so I thought I must try to make one (pair).
I'm converting a van to camper at the moment and a .4x Karlsonator should be light and tidy enough to fit in somewhere.
I've already bought a pair of 3fe 25s, a Sure Electronics AA-JA 32151 amp module, and three sheets of 10mm foamcore. I'm just wondering will I need any particular type of damping in the box?
Hi XRK971, I don't think the za14w08 will work, but can you run it on the driver below? I apologize for the formatting ahead of time, I am on my phone.
Beyma 3FR30:
Specifications:
Impedance 8 ohms
AES Power Rating 30 Watts
Sensitivity (1W/1m) 91dB
BL Factor 4.9 N/A
Thiele-Small Parameters:
Resonant Frequency (fs) 160 Hz
Impedance (Re) 5.6 ohms
Coil Inductance (Le) .25 mH
Mechanical Q (Qms) 8
Electrical Factor (Qes) .52
Total Q (Qts) .49
Comp. Equivalent Vol. (Vas) .024 ft3 / .67 Liters
Voice Coil Overhang (Xmax) 4.5mm
Moving Mass (Mms) 2 Grams
Surface Area of Cone (Sd) .0022m2
Reference Efficiency .5%
Displacement Volume (Vd) 13.5 cm3
I am trying to hit at 103-104db @ 1m before xmax/rms power rating, low f3 is not as critical as I will use a sub, but I am trying to keep the box small. Any suggestions? Would dual 3fe22-16 be better?
Thanks!!
Beyma 3FR30:
Specifications:
Impedance 8 ohms
AES Power Rating 30 Watts
Sensitivity (1W/1m) 91dB
BL Factor 4.9 N/A
Thiele-Small Parameters:
Resonant Frequency (fs) 160 Hz
Impedance (Re) 5.6 ohms
Coil Inductance (Le) .25 mH
Mechanical Q (Qms) 8
Electrical Factor (Qes) .52
Total Q (Qts) .49
Comp. Equivalent Vol. (Vas) .024 ft3 / .67 Liters
Voice Coil Overhang (Xmax) 4.5mm
Moving Mass (Mms) 2 Grams
Surface Area of Cone (Sd) .0022m2
Reference Efficiency .5%
Displacement Volume (Vd) 13.5 cm3
I am trying to hit at 103-104db @ 1m before xmax/rms power rating, low f3 is not as critical as I will use a sub, but I am trying to keep the box small. Any suggestions? Would dual 3fe22-16 be better?
Thanks!!
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