I have been putting Duct Seal on all my drivers since 1983, Always an improvement, even on very expensive drivers.
So, When I built my BK12m's I duct sealed the backs of the Fostex drivers, Additionally I have added some felt to the mouth, and lead and duct seal to the voids in the corners of the cabinets, yet after a few hundred hours of listening, still not all that happy with the result.
My little 4" full range speakers in small sealed cabinets seem to do most things better (except base extension).
What are the listening impressions of other BK12 builders.
Perhaps I should move them to a small room to see if they will do better?
So, When I built my BK12m's I duct sealed the backs of the Fostex drivers, Additionally I have added some felt to the mouth, and lead and duct seal to the voids in the corners of the cabinets, yet after a few hundred hours of listening, still not all that happy with the result.
My little 4" full range speakers in small sealed cabinets seem to do most things better (except base extension).
What are the listening impressions of other BK12 builders.
Perhaps I should move them to a small room to see if they will do better?
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not happy in what regard - bass extension/ slam / impact, etc?
I found them to perform quite well enough considering the design goals, most particularly the small size and front mouth that precludes effective corner loading that definitely benefits the FE126E in a BLH of such shortened path length.
I've heard this driver in at least half a dozen enclosures over the years, and those that elicit "more" of what I'm imagining you were hoping for tend to have any combination of longer path length / larger final flare rates and mouth area, and /or utilize corner loading.
Hi Chris
I built a set of BIB's with 108ez's a few years ago. I built the Bib's with a false bottom to raise the driver to a seated persons ear level, and filled the bottom void with sand. I built the BK12's because I liked the shorter height, but they just seem very shouty, and I tire easily listening to them. I'm using a modified Dynaco Stereo 70, (Which I have another that drives the 108ex Bib's) so very similer setups,
The 108ez Bib's image better, sound Bigger, play louder without fatuiging.
The main difference is the room, so that's what lead to my comment about trying a different room ? (the Bib's and the BK12 are in different houses so I cannot A/B or swap rooms)
Perhaps treating the 126en's with Modpodge ? Or going the whole Modpodge/enable/microgloss routine will help with the shouty fatiguing quality.
EDIT
Also note that I built the BK12's from scratch, not the Madisound kit. Although my wood working is not the best, they came out fairly decent using 3/4" ply.
I built a set of BIB's with 108ez's a few years ago. I built the Bib's with a false bottom to raise the driver to a seated persons ear level, and filled the bottom void with sand. I built the BK12's because I liked the shorter height, but they just seem very shouty, and I tire easily listening to them. I'm using a modified Dynaco Stereo 70, (Which I have another that drives the 108ex Bib's) so very similer setups,
The 108ez Bib's image better, sound Bigger, play louder without fatuiging.
The main difference is the room, so that's what lead to my comment about trying a different room ? (the Bib's and the BK12 are in different houses so I cannot A/B or swap rooms)
Perhaps treating the 126en's with Modpodge ? Or going the whole Modpodge/enable/microgloss routine will help with the shouty fatiguing quality.
EDIT
Also note that I built the BK12's from scratch, not the Madisound kit. Although my wood working is not the best, they came out fairly decent using 3/4" ply.
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a few thoughts on this, in no particular order
In several different enclosures, I found the 108EZ to be far smoother and more "organic" throughout the midrange than the FE126E, even with the latter fully treated with polka dot craziness (with which I'm quite familiar and a big fan of).
Being a much larger and when implemented as originally designed, boundary loaded, the BIB will deliver deeper extension and impact than the BK12
the FE126E is nominally 3 dB more sensitive than the Sigma, and has upper midrange peaks far more pronounced than some of the published graphs would suggest (certainly when compared to the Sigma) - i.e. a dynamic and forward "personality" that some folks find fatiguing
With the full monty EnABL treatment, I personally don't find the FE126s intolerable, but at over 60 and with work related hearing damage and tinnitus, there's a lot of things I don't hear - ask my wife
Unless there was something tragically wrong with your build, I'd imagine most of what you're not enjoying with them is related to that portion of the bandwidth not affected by the enclosure loading.
Did you line / fill the driver chamber with felt or fiber fill? There's always a chance that some of the issues are related to either lack of or excessive damping in the chamber.
There are other enclosures in which the 126 works well - assuming that they'd result in a tonal balance more to your liking - but since this thread is for the BK12, I'll leave it up to your searching (or PM) to find a list of candidates
Hi Chris
Your description seems very accurate.
The BK12 / FE126EN is very nice, and does some things very well, it's just that when doing some critical listening there were a few concerns. The main reason that I decided to build the BK12 was to put by the pool table and, have a floor standing speaker that the butt of the pool cues would pass over. That "personality", as you call it, may be well suited to a room of people playing pool. So for the price and ease of build it is a very good value. The Madisound kit at 315 bucks gets DIY'ers a great fullrange BLH.
A pair of 108EZ's are $ 225, for the drivers alone, So not all that surprising that when A/B'd there are some things I prefer from the more expensive driver and larger cabinet. Duh !
I did stuff the enclosure of the BK12, so I think that some more experimenting there, perhaps adding some more directly behind the driver.
I have stained the BK12's a dark brown to match the pool table, and am considering covering the baffel with Cork, to hide the plywood edges.
Also, I will be adding the metal grills on the FE126EN's to protect them from pool cue butts, so in the end I will not be doing a lot of critical listening with them and they will be ideal for the purpose that I built them.
Your description seems very accurate.
The BK12 / FE126EN is very nice, and does some things very well, it's just that when doing some critical listening there were a few concerns. The main reason that I decided to build the BK12 was to put by the pool table and, have a floor standing speaker that the butt of the pool cues would pass over. That "personality", as you call it, may be well suited to a room of people playing pool. So for the price and ease of build it is a very good value. The Madisound kit at 315 bucks gets DIY'ers a great fullrange BLH.
A pair of 108EZ's are $ 225, for the drivers alone, So not all that surprising that when A/B'd there are some things I prefer from the more expensive driver and larger cabinet. Duh !
I did stuff the enclosure of the BK12, so I think that some more experimenting there, perhaps adding some more directly behind the driver.
I have stained the BK12's a dark brown to match the pool table, and am considering covering the baffel with Cork, to hide the plywood edges.
Also, I will be adding the metal grills on the FE126EN's to protect them from pool cue butts, so in the end I will not be doing a lot of critical listening with them and they will be ideal for the purpose that I built them.
Since the cabinet is rolled off above 300Hz, chances are, as Chris suggests, you simply don't like the 126. It tends to polarise opinion since it has similar characteristics to Lowther drive units. Some love it for that, some can't get on with it. YMMV. The 125 should go in, and is somewhat less characterful, so you could swap them out at some point if it bothers you.
Just Finished Mine
Wanted to thank Planet 10 for the great plans on this build. My first attempt at a build in 20 years. It feels good to be back. I wanted to start from scratch without the pack to learn the woodworking end as well. 3/4 inch oak plywood.
Gear:
Musical Paradise - MP301 MK2 - 7 watt tube amp.
Emotiva- XDA1 -DAC
Hand-Me-Down Dell Computer - Ubuntu - DeadBeef Player
FLAC files from HDTracks
When I ran demos in my living room, I heard the decreased bass response. However, the placement in my "listening room" was closer to the wall (8inches) , and the bass really came out. Very pleased with the sound.
Wanted to thank Planet 10 for the great plans on this build. My first attempt at a build in 20 years. It feels good to be back. I wanted to start from scratch without the pack to learn the woodworking end as well. 3/4 inch oak plywood.
Gear:
Musical Paradise - MP301 MK2 - 7 watt tube amp.
Emotiva- XDA1 -DAC
Hand-Me-Down Dell Computer - Ubuntu - DeadBeef Player
FLAC files from HDTracks
When I ran demos in my living room, I heard the decreased bass response. However, the placement in my "listening room" was closer to the wall (8inches) , and the bass really came out. Very pleased with the sound.
Attachments
Glad you like them. For the size & configuration requirements, I'm pleased with how the BK turned out.
I'm not suggesting it as a general course of action, but if you don't like the FE126En (as evidently the case), the FF125wk should work, and I suspect you will prefer it to the 126.
I'm not suggesting it as a general course of action, but if you don't like the FE126En (as evidently the case), the FF125wk should work, and I suspect you will prefer it to the 126.
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see also my PM re the FE126EN, but a couple more public musings:
it's possible to over-stuff an enclosure which can certainly result in weakened LF extension / impact, exacerbating the 126's forward nature
I quite like the FF125W. although admittedly the nominal 4dB sensitivity penalty compared to the 126 could be a "deal breaker" for some situations, such as use with flea powered SET amps. Compared to the 126, I've personally found it sounds far smoother / less aggressive in the upper mid band than the published graphs would suggest, and at $5 more, still represent an excellent value IMO. If you decide to try them in the BK12s and don't like them, there are several other enclosures in which I've heard them work very well.
Chris
Thanks for further musings.
I only used moderate stuffing as I didn.t have alot left over from previous projects. Also I did follow the plans (Downloaded from Madisound) as per stuffing quantity.
Sensitivity is usually not an issue, and I have the Dynaco Stereo 70, and my room is not overly large.
I'll do some experiments with the other 4" drivers that I have and see what prevails.
Regards
Simon
Thanks for further musings.
I only used moderate stuffing as I didn.t have alot left over from previous projects. Also I did follow the plans (Downloaded from Madisound) as per stuffing quantity.
Sensitivity is usually not an issue, and I have the Dynaco Stereo 70, and my room is not overly large.
I'll do some experiments with the other 4" drivers that I have and see what prevails.
Regards
Simon
Thanks Dave. I'm currently in the process of building the BK-12m (my first attempt at DIY
), sourced the parts at Madi and DIYd the box using 3/4 plywood. Have some more noob questions re this1. do you need to apply silicone sealant to have an airtight seal?
2. fill the i4 and i5 chambers with sand?
3. what's the best route for the internal wire- through a hole at i1 or snake it through the chambers to a terminal cup or binding posts at the back board?
cheers
agsmd793
with a DIY build (as opposed to the Madisound flat-pack) provided clean cut glue edges, I've found standard yellow cabinetmaking glue sufficient - but if you're not completely confident of say the mitered ends of the 3 deflectors, some silicone as well probably couldn't hurt. There's another option that also eliminates the need to fill the voids behind those deflectors - create a staircase of stacked blocks to approximate the slopes. (see PDF)Thanks Dave. I'm currently in the process of building the BK-12m (my first attempt at DIY
1. do you need to apply silicone sealant to have an airtight seal?
provided the deflector voids are fully sealed to avoid leakage, it probably couldn't hurt - but see above
I like to take the shortest route possible; I'd be inclined to install the input terminals approx 100mm from top of back panel so the wires enter just below rear i4 deflector (or stepped blocks), dress them along the top and enter the rear wall of driver chamber, either just below or through the forward deflector. Drill hole just large enough for your wire of choice, and seal with silicone.
Of course you need to do this before attaching the second side.
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1/ Not if the parts are cut well
2/ sure, why not
3/ the best route is the one that works best for you.
dave
My BK-12ms
A big thanks to Planet 10 for this plan, built these from scratch mainly out of 3/4" MDF with a piece of stained beech for the baffle. (I live in Europe so shipping the madisound kit over here wouldn't be worth it)
Powering them off a Topping TP21 class T amp.
A big thanks to Planet 10 for this plan, built these from scratch mainly out of 3/4" MDF with a piece of stained beech for the baffle. (I live in Europe so shipping the madisound kit over here wouldn't be worth it)
Powering them off a Topping TP21 class T amp.
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I recently built the Fostex BK-12m Folded Horn Kit and in many ways I really like them, but found them to be a little fatiguing too. I added some baffle step correction and that seems to have tamed them a bit and I'm no longer fatigued. Also I think as they wear in they are improving too.
They shouldn't require any correction for step loss. That's one of the objects of using a horn in the first place. However, since in practice the 126 does have a rising response / some peaking in the upper registers, a shelving filter (same deal) can help, particularly if you're running a low output impedance amplifer, which the 126 is not designed to be used with.