You should not be dissapointed
Hehehe
I hope that your wife won't hate me for it
You should like the amp, they are great little units, light as a feather with a surprising amount of oomph! They also produce very little heat and consume considerably less energy than a traditional amplifier, the cooling fans rarely even spin up with light usage which makes me happy because not only is the Crown silent but it will also not constantly inhale and accumulate all of this awful arizona dust and therefore not require frequent opening and cleaning
The internal filters seem to work , no complaints there .... I haven't yet pushed the Crowns hard enough to test the clip limiters.
Audiophile caliber sound quality with a character that gives it some subtle and smooth midrange presence (comparing it to the character of the other amps i was using)................... It is strange but widely recognized that even amplifiers which technically measure with flat response (as these do) also still tend have their own subtle tonal signature and luckily it compliments my big living room speaker system well .......
The living room is where i have my two Crown XLS1500s permanently installed as of last week (i swapped everything out after receiving delivery of the second amp), and now for the Karlflex i have a little portable Class D amp based on an NXP/Philips chipset which makes about 180w bridged into an 8ohm load on a switching supply.... This amp has less mid-presence and has turned out to be a great match for the Karlflex .... I have three of these little amps (bought them when a Car Audio company had them on clearance a while back) so i will use one with each Karlflex and have an extra as a backup 🙂
Hehehe
I hope that your wife won't hate me for it
You should like the amp, they are great little units, light as a feather with a surprising amount of oomph! They also produce very little heat and consume considerably less energy than a traditional amplifier, the cooling fans rarely even spin up with light usage which makes me happy because not only is the Crown silent but it will also not constantly inhale and accumulate all of this awful arizona dust and therefore not require frequent opening and cleaning
The internal filters seem to work , no complaints there .... I haven't yet pushed the Crowns hard enough to test the clip limiters.
Audiophile caliber sound quality with a character that gives it some subtle and smooth midrange presence (comparing it to the character of the other amps i was using)................... It is strange but widely recognized that even amplifiers which technically measure with flat response (as these do) also still tend have their own subtle tonal signature and luckily it compliments my big living room speaker system well .......
The living room is where i have my two Crown XLS1500s permanently installed as of last week (i swapped everything out after receiving delivery of the second amp), and now for the Karlflex i have a little portable Class D amp based on an NXP/Philips chipset which makes about 180w bridged into an 8ohm load on a switching supply.... This amp has less mid-presence and has turned out to be a great match for the Karlflex .... I have three of these little amps (bought them when a Car Audio company had them on clearance a while back) so i will use one with each Karlflex and have an extra as a backup 🙂
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Hehehe
I hope that your wife won't hate me for it
You should like the amp, they are great little units, light as a feather with a surprising amount of oomph! They also produce very little heat and consume considerably less energy than a traditional amplifier, the cooling fans rarely even spin up with light usage which makes me happy because not only is the Crown silent but it will also not constantly inhale and accumulate all of this awful arizona dust and therefore not require frequent opening and cleaning
The internal filters seem to work , no complaints there .... I haven't yet pushed the Crowns hard enough to test the clip limiters.
Audiophile caliber sound quality with a character that gives it some subtle and smooth midrange presence (comparing it to the character of the other amps i was using)................... It is strange but widely recognized that even amplifiers which technically measure with flat response (as these do) also still tend have their own subtle tonal signature and luckily it compliments my big living room speaker system well .......
The living room is where i have my two Crown XLS1500s permanently installed as of last week (i swapped everything out after receiving delivery of the second amp), and now for the Karlflex i have a little portable Class D amp based on an NXP/Philips chipset which makes about 180w bridged into an 8ohm load on a switching supply.... This amp has less mid-presence and has turned out to be a great match for the Karlflex .... I have three of these little amps (bought them when a Car Audio company had them on clearance a while back) so i will use one with each Karlflex and have an extra as a backup 🙂
Three XLS 1500s and one XLS 2500 - I may have little bit more than I need ....
IIRC - those were the Guitar Center/Misician's Friend special - I got one of the little ones (X1000 - I think it was $99).
yep - hope it works ~43lb - 20A IEC socket so had to buy an adapter cord - rumored to sound awful (?)- hope no worse than the old Behringer 2500 - xls are pretty good sonically
Actually, they were the darlings over on Tech Talk (and I think AVS, too).
I have heard they are very well suited for sub duty (and are heavy enough to hold the house down).
good - do XLS clip lights ever come on? - do they turn "red"? I could not get my 2000 to indicate clipping into a Trio12
Beau,
Nice Drivecore collection!
You must really like the sound of these if you keep buying them 🙂
Hi Matthew.
Something just crossed my mind. Now that the 2 Freddi Mods Ducts are different in height 7 and 4 cm, then continuing the long duct and folding it is not possible 😕
Could it be done this way?!
Something just crossed my mind. Now that the 2 Freddi Mods Ducts are different in height 7 and 4 cm, then continuing the long duct and folding it is not possible 😕
Could it be done this way?!
OFFICIAL "SIMPLE KARLFLEX" (bi-chamber) SKETCH WITH DETAILS
RESPECTABLE GENTLEMAN AND ACOUSTIC BRAINIACS OF DIYAUDIO
I present my sketch for your review.
It is a humble 2d sketch made in Microsoft paint but provides enough detail to allow almost anyone with basic woodworking skills, basic tools and easily obtainable materials such as birch plywood, PL adhesive, and poly-fiberfil (or fiberglass, or wool) to build one or more of these cabinets.
AN ELEGANT ACOUSTIC CONTRAPTION
BE CHIC AND UNIQUE BY BUILDING THE FIRST SET IN YOUR TOWN!😎
Operating principle is a 6th order series-tuned design but the aperture/mouth geometry allows for extended operating bandwidth. This is made possible by strategically placed stubs, offsets, mass loading, damping materials and taking advantage of the longer wavelengths of bass frequencies which are conducive to coupling between the front chamber and the front of the driver's cone because the driver is somewhat recessed into a mouth which is also fed and shared by the front chamber's vent, all being in extremely close proximity.... However at higher frequencies the front of the cone will begin to decouple from the front chamber, this is a gradual, graceful and reasonably seamless transition...... At 1khz and above the front of the cone becomes almost entirely decoupled from the front chamber (with only a small amount of loading added by the mouth area's depth) and behaves much like a direct radiating system at those higher frequencies in regards to frequency/amplitude response and polar response patterns, so a builder has the convenience of referring to the driver manufacturer's published graphs to predict what the performance above 1khz will be like. 🙂
(more pros/cons and notes will be listed below the sketch)
FAR MORE MOJO THAN YOUR AVERAGE SPEAKER BOX!😱
Below is a measurement of the real-world prototype cabinet which ended up tuned too low ... Once tuning is raised the dip at 300 should be filled in and 40hz output should increase by a few decibels .... As you can see the upper response is not nearly as volatile as the software simulations would have us believe.
THE CHICKS WILL DIG IT!!
(in other words your wife will approve of the compact size.. hehe)
TIRED OF LUGGING AROUND BULKY CABINETS FOR YOUR BAND OR DJ GIGs? YOUR BACK WILL APPRECIATE THESE MUCH MORE. 🙂
I know that this post and even the sketch are all very wordy to the point of being bizarre, sort of like a Dr Bronner's soap bottle! hehehe (ever see one of those? if not you should check one out for fun), I swear that i really do have a reason for the rambling tedium and run-on sentences! I just wanted to make sure that any enthusiast who was considering this project would be well informed because it is the responsible thing for me to do...
Big thanks to everyone on DIY audio who got involved and helped me develop this! IT TAKES A VILLAINAGE! 😉
RESPECTABLE GENTLEMAN AND ACOUSTIC BRAINIACS OF DIYAUDIO
I present my sketch for your review.
It is a humble 2d sketch made in Microsoft paint but provides enough detail to allow almost anyone with basic woodworking skills, basic tools and easily obtainable materials such as birch plywood, PL adhesive, and poly-fiberfil (or fiberglass, or wool) to build one or more of these cabinets.
AN ELEGANT ACOUSTIC CONTRAPTION
BE CHIC AND UNIQUE BY BUILDING THE FIRST SET IN YOUR TOWN!😎
Operating principle is a 6th order series-tuned design but the aperture/mouth geometry allows for extended operating bandwidth. This is made possible by strategically placed stubs, offsets, mass loading, damping materials and taking advantage of the longer wavelengths of bass frequencies which are conducive to coupling between the front chamber and the front of the driver's cone because the driver is somewhat recessed into a mouth which is also fed and shared by the front chamber's vent, all being in extremely close proximity.... However at higher frequencies the front of the cone will begin to decouple from the front chamber, this is a gradual, graceful and reasonably seamless transition...... At 1khz and above the front of the cone becomes almost entirely decoupled from the front chamber (with only a small amount of loading added by the mouth area's depth) and behaves much like a direct radiating system at those higher frequencies in regards to frequency/amplitude response and polar response patterns, so a builder has the convenience of referring to the driver manufacturer's published graphs to predict what the performance above 1khz will be like. 🙂
(more pros/cons and notes will be listed below the sketch)
An externally hosted image should be here but it was not working when we last tested it.
- As some of you already know i have a prototype cabinet built and it is a fine performer, works well, but the fundamental tuning ended up being low compared to the virtual model, so with this new revision i intentionally aimed high on the tuning by a couple of hertz as an attempt to compensate for the discrepancy.... If you (the builder) are concerned about the tuning ending up too high or if you prefer a lower tuning you can add the optional panel (in green) to extend the interchamber vent, and since that panel will be easily accessible (even after the box is built) you can trim, cut or drill that panel post-build in order to raise the tuning if you feel so inclined 🙂
- About "DIMENSION X" (*spooky sci-fi music plays*
) You will want to stay to the high side of this range for 12" drivers and 10" drivers in order to prevent the path from being pinched too much via the gap created by the bottom or the end of the front panel (the panel that forms the front chamber) coming close to the top edge of the driver's frame, you will not want this gap to measure any less than dimension "B" .... So based upon the angle of the baffle make "X"= 2" for 10" & 12" drivers, and for 15" drivers "X"=1.5" inches will be sufficient unless the edge of the driver's frame is very thick, and in that case make "X"=2" ...
FAR MORE MOJO THAN YOUR AVERAGE SPEAKER BOX!😱
An externally hosted image should be here but it was not working when we last tested it.
Below is a measurement of the real-world prototype cabinet which ended up tuned too low ... Once tuning is raised the dip at 300 should be filled in and 40hz output should increase by a few decibels .... As you can see the upper response is not nearly as volatile as the software simulations would have us believe.
An externally hosted image should be here but it was not working when we last tested it.
- Do not be afraid to get a little bit creative with the shape of the "aperture" or mouth for the sake of experimentation and measurements, consider EXAMPLE 1: If you are using a 15" driver in a 20" wide Karlflex this gives you enough room to extend the front panel down on each side of the driver without obscuring the front of the cone and forming what would look sort of like a FU MANCHU mustache shaped aperture! This shape may improve bass coupling between the front of the cone and the front chamber without significantly affecting the upper mid response...... EXAMPLE 2: If you have a driver with a rising upper midrange response then you have the option of adding some removable panels that obscure the sides of the cone to some extent which will tame the rising response with the additional benefit of making your upper midrange's horizontal dispersion pattern very consistent with less "beaming" thanks to this acoustical diffraction lens effect, a feature of the classic K-slot ........ Drivers with the qualifying upper-mid rise (refer to the manufacturer's on-axis response measurement) would be drivers such as the Eminence Beta-12A2 , or the Deltalite II 2512 (or 2515), BassLite S2012 , DeltaPro 12-450A, but unfortunately all of those drivers do not have particularly strong motors, nor do they have extended XMAX capabilities so their sub-bass output is limited in this Karlflex cabinet and will provide that typical overdamped PA bass contour with loud midbass but the output at 40hz is reduced...... In this scenario the builder would not want to tune the cabinets with these drivers too low because it would exacerbate the weak driver's shortcomings so you will surely want to leave out the optional internal duct-extension especially since "squeezing" the mouth area down with these wing panels would result in shifting the fundamental tuning down even further ..................... Higher performance driver alternatives with stronger motors and more XMAX are the Kappalite 3012HO, and Kappalite3012LF (4 and 8) which appear to be the best of both worlds! With their combination of improved bass extension and the higher fidelity bass curve thanks to the superior motor strength combined with the rising upper-mid response which allows for the use of the K-slot-esque diffraction lens method, all desirable characteristics which suggest that these particular Eminence models appear to be excellent choice
.
THE CHICKS WILL DIG IT!!
(in other words your wife will approve of the compact size.. hehe)
- This Karlflex cabinet will not sound like your typical mass manufactured portable compact PA box, at least not with the stronger recommended drivers... To help everyone understand how different these animals sound i will first describe something that most all pro audio professionals will be familiar with for the sake of perspective....EXAMPLE: Most of those typical small PA boxes (if loaded with a 12" or 15" driver) are designed around a different set of compromises and commonly have a large hump in midbass response providing the listener with the impression of subjective bass presence but unfortunately at the same time this leaves one wanting for deeper tones, and that big midbass honk can sound muddy and annoying .... These sorts of cabinets i am describing are standard fare in the Pro Audio world and can be pretty good if used with crossover and separate subwoofer but are lacking if used as standalone cabinets ... ON THE OTHER HAND, The Karlflex has a more neutral sound without that midbass hump (if using drivers with decent motor strength) and offers an extended bass response, the Karlflex was intended to be used without a subwoofer as a standalone cabinet, if you want more output just build more Karlflex cabs
.
- This Karlflex has a dynamic, lively and tight presentation with drums (a characteristic said to be shared with the rest of the Karlson family), while also conveying a warm reproduction of vocals and instruments, very tastefully emphasizing the resonance contained within those sources, a chameleon-like coloration ... Some amount of resonant midrange coloration is unavoidable due to the front chamber, but i rather appreciate the texture of this highly broadband and adaptable form of coloration, it sounds pleasant to me, and just seems to somehow bring forth already existing resonances contained in voices and instruments without adding much of it's own resonance to sources that have none to begin with. This was an unintentional side-effect of the design but i am not complaining 🙂
- THIS IS AN UNDERSIZED BOX at about half the size of a Tapped Horn (using the same tuning and the same driver) so do not expect the extremely high efficiency of a large TH or Front Loaded Horn unless using these in multiples but you can expect to get bass output that will keep up with the mids as long as the midrange sensitivity rating of the driver is not too high (the spec that the manufacturer provides is classically taken at 1khz) ... I can say from experience that when using a 12" driver with a 96db @1w/1m rating in a 60 liter Karlflex it has a decent tonal balance
but if my 12" driver were rated at 99db @1w/1m it would sound too hot in the midrange which can be fixed with EQ but some of us prefer not use any EQ if we can help it .... If we are talking about a 15" driver in the 120 liter Karlflex you could get away with using something that has closer to a 99db @1w/1m rating (assuming all other T/S parameters are in proper ranges) and would likely have a neutral tonal balance (without EQ), as opposed to a 15" driver with 93db @1w/1m sensitivity in that same 120L cab which would produce a more bass-heavy tone .... It is all relative....
TIRED OF LUGGING AROUND BULKY CABINETS FOR YOUR BAND OR DJ GIGs? YOUR BACK WILL APPRECIATE THESE MUCH MORE. 🙂
- Some drivers that need larger cabinets such as the Kappalite 3015lf-4 or the Kappa Pro 15LF-C will produce an overdamped bottom end contour that people will recognize as similar to the standard PA bass sound, and some people may prefer that familiar extra punch of additional output between 60hz and 150hz-ish at the expense of some output at 40hz ... This midbass dominant contour would also more closely resemble the classic Karlson curve, so if that is what you want then your choice in driver is key to making that happen. 🙂
- COMPRESSION DRIVER OR TWEETER MATCH: Make your choice based upon the woofer/driver or midwoofer that you will be using (just as you would if building a two-way reflex cabinet, this could also be done as a three-way if you really wanted to), matching sensitivity ratings and finding the right crossover points according to your driver's polar response patterns is important ..... I got lucky with my Dayton PA310 drivers as their dispersion is acceptable enough for me up to 2khz (verified at 45 degrees VS on-axis measurements) and i just happen to have some good custom horn tweets that run smooth from 2k on up with sensitivity of around 99db that i have been wanting to use, but i know that many other people would prefer to crossover lower than that, and people also have their personal preferences for a hot high end or a subdued high end so i will leave this part up to you guys to decide upon for yourselves 🙂...
- I SAY THE FOLLOWING NOT TO BE NEGATIVE, BUT BECAUSE I DO NOT WANT TO GIVE ANYONE ANY FALSE HOPES, LETS BE REALISTIC: The Karlflex will not miraculously fix your room, meaning it will still be negatively affected if your listening space has insufferable acoustics, in other words if your room sounds like a trainwreck (no matter what speakers you have tried in there) then you should consider installing some forms of sound treatment.............................................. Nor will the Karlflex fix poorly recorded music, if your source material is bass deficient, or clipped, or lacking resolution from poor digital encoding, or squashed or whatever, that mess will simply be faithfully reproduced by the Karlflex ... Garbage In=Garbage Out, The Karlflex is not a magical automatic turd polishing device
.................. Also, even though the Karlflex was designed to be used without the need for a separate subwoofer it will not sound like DJ Thumpmonster's multi-amped system with his sub channel gains overpumped, the Karlflex is not bass-obnoxious but instead it is faithful and neutral, like listening to music over a decent set of headphones..
- I see tremendous potential for dollar-per-decibel & pack-space value in the use of these (or similar variant) as modules in larger arrays when entertaining larger crowds at sizable events. These should prove to be effective when used in herds stacked on their sides as line arrays or can also be arranged as splayed cluster arrays...... Used in this manner it would be hard to beat their value since separate subwoofers would not be required in such a scenario , the Karlflex cabinet would provide reproduction between 40hz and 1khz (to 2khz) while separate Horn loaded compression driver arrays (or tweeter arrays) could provide the 1khz to 2khz and up .......
I know that this post and even the sketch are all very wordy to the point of being bizarre, sort of like a Dr Bronner's soap bottle! hehehe (ever see one of those? if not you should check one out for fun), I swear that i really do have a reason for the rambling tedium and run-on sentences! I just wanted to make sure that any enthusiast who was considering this project would be well informed because it is the responsible thing for me to do...
Big thanks to everyone on DIY audio who got involved and helped me develop this! IT TAKES A VILLAINAGE! 😉
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I concur with this train of thought. Once had a similar plan, but ran short
of practical stuff, like having not a spare dime to spare for plywood, or a
workspace that would long tolerate the slow pace and high mess factor
that I prefer to work at. To the best of my knowledge, no one has ever
been mentally disturbed enough to build it. You could be first!
of practical stuff, like having not a spare dime to spare for plywood, or a
workspace that would long tolerate the slow pace and high mess factor
that I prefer to work at. To the best of my knowledge, no one has ever
been mentally disturbed enough to build it. You could be first!
Attachments
post 1611 is a marvelous, succinct (detailed graphic) and auspicious point in the thread so far 😀😀 - - ( Kenpeter's K-variant is cool)
Series resistor can fix overdamped. Nothing can fix underdamped...
Which side of this conundrum would you prefer to error upon?
---------
377.5 Litres. As if anyone would still be counting after first 300L.
Might just barely wedge a 21" in there, but was thinking for 18".
Past experience with overstuffed Karlson, don't recommend it...
Made sure to limit depth dimension 20" to fit through door. With
clearance for hinge maybe not swinging entirely out of the way...
---------
Your 123L box comes to 172.3L by my math (outside dimensions).
Which side of this conundrum would you prefer to error upon?
---------
377.5 Litres. As if anyone would still be counting after first 300L.
Might just barely wedge a 21" in there, but was thinking for 18".
Past experience with overstuffed Karlson, don't recommend it...
Made sure to limit depth dimension 20" to fit through door. With
clearance for hinge maybe not swinging entirely out of the way...
---------
Your 123L box comes to 172.3L by my math (outside dimensions).
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If you build Karlflex with a traditional exponential cut (for dispersion),
plan some way you can remove those wings. Cause looks impossible
to install your driver into that design from any vantage but the front.
-------
I went bottom access non-removable in my above plan. Cause all my
removable wing experiences have been want for some extra bracing
that just wasn't practical. Figure all bracing should have function, and
all function should provide bracing. Only two small panels in mine
(serve as bracing only) fail to meet the dual purpose criteria.
You could jam a pillow sideways through the two holes in the braces
and claim a function. But wan't part of the plan, just afterthought.
Was really thinking, "what if it needs to breath there for the slot to
work properly?"
Not saying with any certainty that its even an issue. But right where
proper breathing K slot can usually blow out a candle. I worry a bit,
what obstruction those braces might inadvertently become.
At 48" tall, would not expect to need an extra Freddi stub to fake it.
plan some way you can remove those wings. Cause looks impossible
to install your driver into that design from any vantage but the front.
-------
I went bottom access non-removable in my above plan. Cause all my
removable wing experiences have been want for some extra bracing
that just wasn't practical. Figure all bracing should have function, and
all function should provide bracing. Only two small panels in mine
(serve as bracing only) fail to meet the dual purpose criteria.
You could jam a pillow sideways through the two holes in the braces
and claim a function. But wan't part of the plan, just afterthought.
Was really thinking, "what if it needs to breath there for the slot to
work properly?"
Not saying with any certainty that its even an issue. But right where
proper breathing K slot can usually blow out a candle. I worry a bit,
what obstruction those braces might inadvertently become.
At 48" tall, would not expect to need an extra Freddi stub to fake it.
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K-relatives
Kenpeter,
Very nice K-variant! There are some resemblances, offset driver, nice long path length and such...
Looks about right for an 18 🙂
Have an Akabak script for this?
Kenpeter,
Very nice K-variant! There are some resemblances, offset driver, nice long path length and such...
Looks about right for an 18 🙂
Have an Akabak script for this?
(and yes on the Kenpeter K, looks neat!)
Nice sum up, of your impressive work
What you discripe about the Karlflex sound is very interestingly. This vibrant resonance sound will definitely set it apart from the ordinary home box speaker, which I often think sounds a sort of dry, lacking texture and livelyness, in short unmusical.
I know that Audio Note also "tune" their speakers cabs like instruments, so they ad richness and texture.
So about the front aperture, would it be counterproductive to bracing it to much, making it to rigid?
with regular Karlson playing a higher levels, the wings and back panel need bracing - bass tautness suffers and wing deflection makes a "shimmering" modulation sound - similar can happen with poorly braced horn mouths, thin direct radiator baffles.
- look at Guits' 2nd video to see a K15's 18mm plywood wings deflecting quite a bit
http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-72.html#post4481365
video from that post https://goo.gl/photos/ByhFAJ6sWffwZin67
- look at Guits' 2nd video to see a K15's 18mm plywood wings deflecting quite a bit
http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-72.html#post4481365
video from that post https://goo.gl/photos/ByhFAJ6sWffwZin67
Stuffing and stuff
Overstuffed would be a bad thing for sure, some stuffing in the offset section and stubs sees like a good way to go for good effect without too much loss ... I also suggested some lining behind the driver to cut back on the internal mid reflection making it's way back through the cone as some out of phase nastiness (after lining the lower part of the forward facing side of the S1 panel on the prototype it seemed to mellow out the mids a little) ...
---------
I am just using my trusty ole box size calculator from winISD , accounting for 1/2" ply and the extra internal panels etc .... It is an approximation ... If i apply the exact same compensation to the 60L (same as applied to the larger cabs) i end up with something like 63 liters which is close enough for me 🙂
Overstuffed would be a bad thing for sure, some stuffing in the offset section and stubs sees like a good way to go for good effect without too much loss ... I also suggested some lining behind the driver to cut back on the internal mid reflection making it's way back through the cone as some out of phase nastiness (after lining the lower part of the forward facing side of the S1 panel on the prototype it seemed to mellow out the mids a little) ...
---------
I am just using my trusty ole box size calculator from winISD , accounting for 1/2" ply and the extra internal panels etc .... It is an approximation ... If i apply the exact same compensation to the 60L (same as applied to the larger cabs) i end up with something like 63 liters which is close enough for me 🙂