MrShazBot,
Thanks for sharing your dual 3FE25 Karlsonator build! If you take a sharp utility knife, you can trim and clean up that curved aperture to make it smoother. It will look better and maybe even sound nicer. Otherwise the construction looks good. If you have any pinhole air leaks in the sealed TL end above the drivers, or if the driver gaskets are leaky - you might lose some deeper bass. (In the same way that if you play a flute and you have a small leak on a finger pad, you can’t hit the low C note). I think mine don’t start to fall off until below 75Hz. But if you have a sub, doesn’t matter. Your measurements look great the wiggles in the mid are the nature of the K aperture. But your measurements are surprisingly balanced and neutral. The HF reach is remarkable.
Thanks for sharing your dual 3FE25 Karlsonator build! If you take a sharp utility knife, you can trim and clean up that curved aperture to make it smoother. It will look better and maybe even sound nicer. Otherwise the construction looks good. If you have any pinhole air leaks in the sealed TL end above the drivers, or if the driver gaskets are leaky - you might lose some deeper bass. (In the same way that if you play a flute and you have a small leak on a finger pad, you can’t hit the low C note). I think mine don’t start to fall off until below 75Hz. But if you have a sub, doesn’t matter. Your measurements look great the wiggles in the mid are the nature of the K aperture. But your measurements are surprisingly balanced and neutral. The HF reach is remarkable.
Thanks. I doubled up the K aperture because it was really vibrating and making a slight noise. I couldn’t find my extra blades so I practically had to saw that last piece with a dull blade!
I’m sure I have a leak in the TL somewhere but it’s not a huge deal.
I’ll probably make a wood enclosure for it soon because I really like how it sounds.
I’m sure I have a leak in the TL somewhere but it’s not a huge deal.
I’ll probably make a wood enclosure for it soon because I really like how it sounds.
I think that I'm the one who built the very first dual 3FE25-16 K's and I've been listening to it ever since. Like X says, there is bass down to below 80Hz, but it's always been weak, bass-wise.
Recently I've added an active sub and my Karlsonators came alive - especially the bass. It's like different speakers now. It sounds like the bass is coming from the Karlsonators, not the sub. So, a subwoofer or two with the Karlsonators is highly recommended.
Recently I've added an active sub and my Karlsonators came alive - especially the bass. It's like different speakers now. It sounds like the bass is coming from the Karlsonators, not the sub. So, a subwoofer or two with the Karlsonators is highly recommended.
I still use my dual 3FE25-16 K's as my main speakers. I love them. Still working on adding a subwoofer, I have one from an old home theater kit and a small class D amp for it, just need to make a low pass filter for it, as the built in one crosses at ~150hz or so and I can't figure out the schematic from the PCB.
Mini K’s With Open Baffle Bass
I built some open baffles to experiment with adding more low end to my system this weekend. They’re roughly based on John Busch’s Manzanitas in terms of the GRS15 woofers, baffle size and wings and the 20mH inductor on the XO. I have an 8 Ohm mills resistor in series with the 0.53x Mini-k with dual 3fe25’s. I like what I’m hearing so far. They blend pretty well and give the low end I was missing along with some good punch on percussion. I think the woofers still need some break-in time to loosen up the surrounds and things will get even better. Maybe some more XO experimentation later this week too.
I built some open baffles to experiment with adding more low end to my system this weekend. They’re roughly based on John Busch’s Manzanitas in terms of the GRS15 woofers, baffle size and wings and the 20mH inductor on the XO. I have an 8 Ohm mills resistor in series with the 0.53x Mini-k with dual 3fe25’s. I like what I’m hearing so far. They blend pretty well and give the low end I was missing along with some good punch on percussion. I think the woofers still need some break-in time to loosen up the surrounds and things will get even better. Maybe some more XO experimentation later this week too.
Attachments
Thanks for sharing. I have been thinking about doing something similar for a long time now and might just attempt it early next year. Are you running both sets of speakers from one amp? I am planning to try bi-amping but not sure how to implement the XO yet.I built some open baffles to experiment with adding more low end to my system this weekend. They’re roughly based on John Busch’s Manzanitas in terms of the GRS15 woofers, baffle size and wings and the 20mH inductor on the XO. I have an 8 Ohm mills resistor in series with the 0.53x Mini-k with dual 3fe25’s. I like what I’m hearing so far. They blend pretty well and give the low end I was missing along with some good punch on percussion. I think the woofers still need some break-in time to loosen up the surrounds and things will get even better. Maybe some more XO experimentation later this week too.
Your Manzanita like baffles are slightly different with the added wings to the front of the baffle. What is the reason for this? Getting closer to a H frame. I will be using a 12” driver, so I’ll be using the 12” Manzanita baffle size and add some wings (maybe 4”) to the back only.
Hi twocents. Yes, they’re running off of a single amp. Right now it’s my F7 clone (Class A with lateral mosfets) and have a WHAMMY as the pre. Great combo and still plenty of headroom left even with 20-ish Watts. According to my XSim simulation this combo should still be about 88-90db efficient.
Check out the Manzanita thread around post #1776 for an explanation of the wings by John Busch. He did 2.5” in the front and 5” in the back. I would think it’s getting closer to an H frame, yes. He may have also given some info about using this with the 12” peerless woofer later in the thread.
I can say the experiment was worth it if you’re looking for extended, toneful lows. It’s still not going to give you earthshaking, window rattling bass, but that’s not what I’m after. It was a plus I already had my table saw set up for another home improvement project so I was able to cut the parts from 4’x4’ of mdf with almost zero waste. I put them together in about 3-4 hours of work from start to finish.
Nice work Jwarch! It must sound great. I can imagine the sound of the open baffle bass is very clean, dry, and tight. Not flappy. Bravo!
Btw, thanks for plans!
I am in the kitchen working on the computer and listening to Diana Krall on my dual 3FE25-16’s in the wooden cabinets that Jhofland made for me. Beautiful sound. No sub but still great.
I am using a basic commercial boxed Class D amp with an Amazon Dot as the source. Works great for a kitchen radio.
Btw, thanks for plans!
I am in the kitchen working on the computer and listening to Diana Krall on my dual 3FE25-16’s in the wooden cabinets that Jhofland made for me. Beautiful sound. No sub but still great.
I am using a basic commercial boxed Class D amp with an Amazon Dot as the source. Works great for a kitchen radio.
Thanks X. Yes, the bass is nice and tight. You can really hear every note. Especially good with upright bass. A track i'm really enjoying right now is The Eagles, Hotel California, Live from a 1994 MTV concert on the Hell Freezes Over album. The bongo drums on the intro sound so realistic impact wise.
Another plus of the combo are the minimal XO components (only 2 right now). Although I'm planning on experimenting with another solution to roll the mini-k's off on the low end with a 2.5mH inductor and 16 ohm resistor, and invert the polarity. Then roll the highs off on the GRS15's with 44uF worth of caps. Image attached. Sensitivity will certainly take a hit but may sound better overall. I'll let you know.
Not a bad kitchen system, indeed! The 3fe25's really do make a great speaker. I still have to glue some felt to the back of the apertures. I'm sure that will take things up another notch as well.
Another plus of the combo are the minimal XO components (only 2 right now). Although I'm planning on experimenting with another solution to roll the mini-k's off on the low end with a 2.5mH inductor and 16 ohm resistor, and invert the polarity. Then roll the highs off on the GRS15's with 44uF worth of caps. Image attached. Sensitivity will certainly take a hit but may sound better overall. I'll let you know.
Not a bad kitchen system, indeed!
The 3fe25's really do make a great speaker. I still have to glue some felt to the back of the apertures. I'm sure that will take things up another notch as well.Attachments
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Jwjarch, thank you for the info and CAD files. I have 0.4x Karlsonators with TC9FD18 drivers. I was thinking of building Manzanitas long ago but in the end the cost of the inductors let me change my mind, so I built the Karlsonators in stead, and I love them. With the addition of 12” OB woofers the setup might sound something like the Manzanitas, provided I can get the bi-amping and XO sorted. The other motivation for building the 12” OB woofers is because I am thinking of playing with DML panels and will need bass support. Too many plans, too little time.
For woofers don’t be afraid to use iron laminated core inductors to get the big mH values. No need for air core. Also, smaller gauge wire is OK too. Adds a bit of series resistance which will improve OB bass extension by making Qts larger.
Use two 10mH 18AWG in series for half the price of a 20mH 16ga. DCR of 0.78ohm x 2 = 1.6 ohms. Vs 16g which is 0.6ohms. An extra ohm of DCR is no big deal - and save $20ea.
Dayton Audio 10mH 18 AWG I Core Inductor Crossover Coil
Use two 10mH 18AWG in series for half the price of a 20mH 16ga. DCR of 0.78ohm x 2 = 1.6 ohms. Vs 16g which is 0.6ohms. An extra ohm of DCR is no big deal - and save $20ea.
Dayton Audio 10mH 18 AWG I Core Inductor Crossover Coil
That’s a great tip X! Wish I had thought of that. Haha! I sprang for the 20mH inductors instead. Oh well... I may also play around with my minidsp 2x4hd eventually. I feel the same way twocents. Between amp, preamp, and speaker building there is never enough time. Not to mention life getting in the way every now and then
Yes, life and work and sh$t happens all the time, and that has to be tended to. Nice thing about DIY is that it’s always there when you have time and come back (well almost always). A member told me that he took a break to find his wife had thrown out some of his stuff because she was cleaning up and it was lying around in a kraft bubble mailer envelopes and looked like junk. Be sure you put it away in a safe place! These were new PCBs he had ordered from me but did not get to use.
I am using two madisound 10" woofers, each in a 63L Speakerlab wooden vented box for subs; something leftover from speaker building in a different century. I drive them with about $20 worth of electronics from China, an electronic crossover and two 3118's. Huge. this augments my two Xiclops and 28" Cornu's driven by one 3eaudio 3251, with a customized acurus preamp. I listen to mostly jazz. Acoustic instruments on this setup sound like they are in my living room. Upright bass is shockingly great. If more zing is needed I add a pair of MK's each w/ two TC9FD18's. X's designs have rocked my world and we're all better for it.
Spent some time listening to the XO configuration I posted on post #3491 last night. In fact I couldn’t stop listening! This XO has taken things to a new level. I was experiencing some obvious resonances with the mini k’s on this like bass guitar before. That has all been cleaned up and I feel like the mini k’s and the GRS15’s are blending more seamlessly than before. Efficiency is down but I thing I still have enough power to get the volume I want. Time will tell with more hours in the listening chair.