But the B110 is a small driver. Too small to function reasonably as a woofer. The parameters suggest a volume of about 5-6 litres for a sealed box and a volume of about 10-12 litres for a ported box.
The Daline and Mini-line both consist of an enclosure plus a long line and both look to be around the same volume. The Daline stuffs the line which addresses one of my concerns. In the Daline the incompressible port resonance is below 20 Hz and not really a factor. Don't know about the Mini-line but the business about cross sectional area is a concern.
The Daline has been designed to be used flat against a wall which raises the bass about 6 dB and removes the need for baffle step correction in the crossover. Given the tiny driver this looks a good move so long as the speaker can be placed flat against a wall. The mini-line looks to be a more conventional arrangement so goodbye to 6dB gain where it is needed.
Given both speakers use an unconventional and unpopular arrangement (i.e. one that almost certainly does not do well in terms of performance for cost) I would suggest being rather wary without some measurements to show things are under control.
My point was that the author claims stiffness is important and then does not apply it in the design. I would need to investigate further to determine if 6mm and/or 12mm is adequate but it is a fair bit thinner than what is normally used in DIY speakers that seek to be high quality.
Only if the design is poor. A precise amount and type of stuffing is part of the design of a competent transmission line. The lowest frequency compressible line resonance needs to be impeded as little as possible whereas all the higher frequency line resonances need to be blocked as much as possible. Stuffing can also change the speed of sound in the line and hence the frequencies of the resonances. There is quite a lot to juggle in a competent design with little wiggle room left at the end.
My point was that different density materials have nothing to do with damping. A sound wave hitting the interface between materials of different density will be partly reflected and partly transmitted. This is not damping but it is another indication, like the above, that the author may not be fully on top of things. I should stress that I lack the evidence to say whether the mini-line is a good, bad or middling design but some of the signs are not encouraging.
Plywood is a significantly stiffer than MDF. Why do you think MDF might be a preferable material?
A disaster would be easy. A more likely outcome is that you spend considerable money and effort to get something that doesn't perform badly but doesn't perform well either. For example, you are not going to get satisfactory bass out of a B110 but the modest level that is present may be OK at modest listening levels and appropriate types of music. It will be a step down from what you are currently used to assuming your current speakers are competent examples.
In your position, LS3/5A main speakers with B139 subwoofers would seem a reasonable and safe way to get smaller size, good performance and little risk for someone with little knowledge about speaker DIY. One concern would be that running the B110 down to 100 Hz or so rather than a more reasonable 400 Hz will limit how loud the system will play cleanly. If it becomes an issue then moving the subwoofers near the main speakers would allow the crossover frequency to be raised to some extent.
Another option might be to simply to put what you already have in a 12" x 24" x 12" sealed stuff box if this is a more domestically acceptable size. This should give a Q of about 0.7 and f3 of a bit above 50 Hz if the parameters in the spec sheet are to be believed. It is likely to outperform anything you can do with just the midrange and tweeter alone. Crossover might benefit from a bit of tweaking though.
Thanks for the detailed feedback Andy, much appreciated. I will think about most of your posts but the ones above can be addressed easily.
- Let me be clear, ALL of the external cabinet walls are 12 mm except for the base which for some reason is 18 mm. There is extensive bracing. No walls are 6 mm. I believe that the LS3/5a had 12mm unbraced but damped walls and when I suggested that thicker walls might be a good idea, many people here disagreed.
- I wasn't suggesting the exclusive use of MDF, just 6mm MDF on the inner walls and 6mm ply on the outer walls. However, as I said, I would be unlikely to try this experiment.
- Much as I would love to (it would be very easy to put together), I really can't take seriously your suggestion that I should place a B139, B110 & T27 in a 24" x 12" x 12" infinite baffle cabinet. Kef are quite clear that the B110 should be placed in an IB box of 4.25 to 7.26 litres and the B139 should be placed in a reflex IB box of 62 litres - your mileage may vary but not to the extent you suggest.
They were quite right to disagree because the fairly complex LS3/5A cabinet has been designed to work in a particular way using thin walls and lots of damping. However, this is not the normal way to make a cabinet that is acoustically inert where you would use thicker walls.
I don't know where you are getting this duff information but, for example, there are suggested sizes for sealed enclosures on the KEF B139 spec sheet!
A port in a large box will give significantly deeper bass but at the expense of degraded transient response. However, the limited linear excursion and the low "natural" tuning means the port isn't helping much where it is needed when playing at higher SPLs. Sealed probably looks the better option and using a subwoofer if you want clean thunderous bass.
Which B139 do you have? The later B139B needs smaller cabinets than the earlier B139.
Despite not accepting your "box" suggestion I do appreciate your feedback, many thanks Andy . . . now if you could help with the design of a crossover for the Atkinson Mini-Line . . .
Well if telling you not to do it is helping.
Poor old andy19191. Trying to give good advice and it's falling on deaf ears!
I just wouldn't waste time on a 5" driver in a 8L closed box. It just isn't a good sound overall. No bass. Much better in a three way where you can preserve the midrange strengths.
So why do people still hanker after these old speakers? And Wilmslow Audio are doing a commendable job of keeping them alive:
STAND MOUNTING Loudspeakers
A reflex LS3/5A clone, which looks good, a Heybrook HB1 and a Heybrook HB2 using those lovely old Vifa midbasses:
Vifa Bass-Mid and Bass Units
The Heybrook HB1 is a bit flawed IMO with first order tweeter, despite the nice Vifa M21 bass unit. But the HB2 with the polycone Vifa P17 was rather good:
A classic BW3 crossover. Troels Gravesen always agonises between "integrated" LR2 and "dry" LR4 filters. What is special about BW3 is it has flat power delivery. Which means it doesn't have that unpleasant hole in power response at crossover that comes with even order filters. Combine that with a tweeter Zobel, and you know what was good about the LS3/5A.
But frankly, the art has moved on. Spendor and Harbeth use much tidier 5" woofers these days. And better tweeters. But still around 3-4 kHz negative polarity BW3 crossover, because that is what makes the magic work.
I just wouldn't waste time on a 5" driver in a 8L closed box. It just isn't a good sound overall. No bass. Much better in a three way where you can preserve the midrange strengths.
So why do people still hanker after these old speakers? And Wilmslow Audio are doing a commendable job of keeping them alive:
STAND MOUNTING Loudspeakers
A reflex LS3/5A clone, which looks good, a Heybrook HB1 and a Heybrook HB2 using those lovely old Vifa midbasses:
Vifa Bass-Mid and Bass Units
The Heybrook HB1 is a bit flawed IMO with first order tweeter, despite the nice Vifa M21 bass unit. But the HB2 with the polycone Vifa P17 was rather good:
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An externally hosted image should be here but it was not working when we last tested it.
A classic BW3 crossover. Troels Gravesen always agonises between "integrated" LR2 and "dry" LR4 filters. What is special about BW3 is it has flat power delivery. Which means it doesn't have that unpleasant hole in power response at crossover that comes with even order filters. Combine that with a tweeter Zobel, and you know what was good about the LS3/5A.
But frankly, the art has moved on. Spendor and Harbeth use much tidier 5" woofers these days. And better tweeters. But still around 3-4 kHz negative polarity BW3 crossover, because that is what makes the magic work.
surv1v0r, you request suggestions for a crossover for the Atkinson mini-line. I would suggest KEF's own design, http://www.hifiloudspeakers.info/Anatomy/KEFDocuments/KEFCS1A/KefCross.gif
This is intended for a smaller baffle size than the mini-line, I believe, but KEF's ability to design crossovers that compensated for their drivers imperfections were renowned at the time, imo. You may find original crossover designs for the mini-line or the LS3/5 but I am sure they will sound less neutral than the KEF design.
This is intended for a smaller baffle size than the mini-line, I believe, but KEF's ability to design crossovers that compensated for their drivers imperfections were renowned at the time, imo. You may find original crossover designs for the mini-line or the LS3/5 but I am sure they will sound less neutral than the KEF design.
Another thought would be to take another look at the 1070s Linkwitz article that actually used these same drivers.. . t27, b110 and b139 in a thoroughly thought-out design...
SB1980-3way
SB1980-3way
Ah, back to the old 8L box and KEF's bolloxed and long abandoned and broken Acoustic Butterworth filter.
Let's run on for another 15 pages of pointless rubbish. But I explained it. I can only do what I can do. Small drivers in small boxes don't do bass very well.
And why use the old KEF B139. Surely the art has moved on, jplesset, even if it claims the dubious vales of an active system? Don't live in the past.
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Many thanks for that ertner - on topic - WOW!
Someone pointed me in the direction of the CS1A crossover earlier today and I am aware that Falcon Acoustics list the CS1 crossover but it seems to be for use with the B110 SP1057, should this work correctly my B110 SP1003?
Someone pointed me in the direction of the CS1A crossover earlier today and I am aware that Falcon Acoustics list the CS1 crossover but it seems to be for use with the B110 SP1057, should this work correctly my B110 SP1003?
Of course it won't. The SP1057 was more of a midrange driver than a midbass. A smoother driver.
You seem not to be keeping up, sometime ago I saidAh, back to the old 8L box and KEF's bolloxed and long abandoned and broken Acoustic Butterworth filter.
Let's run on for another 15 pages of pointless rubbish. But I explained it. I can only do what I can do. Small drivers in small boxes don't do bass very well.
And why use the old KEF B139. Surely the art has moved on, jplesset, even if it claims the dubious vales of an active system? Don't live in the past.
ertner seemed actually to understand my question and to have tried to help.
As to the B139 - frankly I don't care, it is not relevant in this context, I want to place a B110 and T27 that I have in the Atkinson Transmission Line cabinet - everything else is just noise.
OK?
ertner didn't understand your question at all. He just rehashed the rotten old KEF Constructor CS1A design.
You see, you seem to think you can break the laws of physics here.
I'm just trying to save you wasted effort. But let the forum majority win. That's how it goes. Even if they are wrong.
You see, you seem to think you can break the laws of physics here.
I'm just trying to save you wasted effort. But let the forum majority win. That's how it goes. Even if they are wrong.
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This is getting a bit ragged. I suggest the OP talks to Falcon, who have more experience with the B110 than anyone else and have reintroduced the driver.
I suspect they're going to recommend the LS3/5a design but let's wait and see.
Although I raised the Mini-Line as an interesting design from the period when the B110 was popular, I don't know anyone who has built it, whereas the Daline and LS3/5a derivatives have a lot of history and user feedback.
Worth pointing out that although the LS3/5a doesn't really do bass below 100Hz it does do the illusion of bass and that may be perfectly satisfactory. If you have suitable drivers you can add real bass later as your ideas and experience evolve.
I suspect they're going to recommend the LS3/5a design but let's wait and see.
Although I raised the Mini-Line as an interesting design from the period when the B110 was popular, I don't know anyone who has built it, whereas the Daline and LS3/5a derivatives have a lot of history and user feedback.
Worth pointing out that although the LS3/5a doesn't really do bass below 100Hz it does do the illusion of bass and that may be perfectly satisfactory. If you have suitable drivers you can add real bass later as your ideas and experience evolve.
It is obviously OK in the sense that it is your project to do with as you see fit. What is perhaps less OK is expecting "helpful" rather than "unhelpful" input when you baffle people with decisions that do not line up with your stated objectives or implicit objectives like minimising cost and maximising performance.
How have you ended up opting for a design?:
- that almost nobody has built
- gives the appearance of being poorly designed
- has no supporting measurements to alleviate concerns
- is relatively complicated and expensive to build
- is not designed for the drivers you are going to use
- for which you do not have a good crossover
- for which you do not have an obvious way of obtaining a good crossover
- has poor bass and limited SPL
- etc...
Do you want a good crossover or would you settle for a crossover that will work but not necessarily particularly well? The former requires a purpose designed crossover for your drivers and your cabinet which is a normal part of the DIY speaker process. If you do not want to design the crossover yourself I can see no practical way for you to get a good crossover for this cabinet but I can see various ways you might get a crossover that does something passable:
- use the relevant tweeter and midrange parts of the crossover you already have so long as they are independent of the woofer components
- ring up Falcon and do what they suggest assuming they are prepared to suggest something
- obtain the parameters for your tweeter and the tweeter used in mini-line, post the circuit and ask what values to change
The guy is having a hobby, it is not supposed to make sense, give him a break.
I built the Decca Corner Horn, flimsy walls, weird flare and no damping material what so ever and in the end was surprised that it could sound so good. The mini TLS has some weird things like stating that proper sealing in line is not that important. But still the hobby project to use vintage drivers fitting a vintage design, why not?
If he wanted maximal sound quality for the money why not buy second hand modern mini speakers of good quality, but what is the fun in that...
There must be people in the UK audio fora that has built the mini tls, snoop around.
I built the Decca Corner Horn, flimsy walls, weird flare and no damping material what so ever and in the end was surprised that it could sound so good. The mini TLS has some weird things like stating that proper sealing in line is not that important. But still the hobby project to use vintage drivers fitting a vintage design, why not?
If he wanted maximal sound quality for the money why not buy second hand modern mini speakers of good quality, but what is the fun in that...
There must be people in the UK audio fora that has built the mini tls, snoop around.
That is interesting since there doesn't seem to be much about them on the web. Did you build the mini-line to spec with 6mm walls, unstuffed line,... or did you modify them a bit? Do you have measurements you can show?
I build the mini line interior within the specs and the outside of the cabinet with a sandfilled layer.
A very solid build. Midrange was ok, but the bass of the daline was more impressive and overall better balanced. The daline needs to be with the back against the wall.
The Atkinson SOTA has a very impressive deep TL-bass sound and the best midrange I have ever heard from the KEF B-110 driver. I reduced the SOTA to a 3 way system instead of the 5-way (with 6 drivers) Atkinson designd. I believed a 5-way system was over the top!
Funny enough now I am building a complete 4-way active DSP controled system and I would like to have a 5-way system to cover the audio spectrum.
The Daline and SOTA I build about 25 years ago but are still in use by my friends.
A very solid build. Midrange was ok, but the bass of the daline was more impressive and overall better balanced. The daline needs to be with the back against the wall.
The Atkinson SOTA has a very impressive deep TL-bass sound and the best midrange I have ever heard from the KEF B-110 driver. I reduced the SOTA to a 3 way system instead of the 5-way (with 6 drivers) Atkinson designd. I believed a 5-way system was over the top!
Funny enough now I am building a complete 4-way active DSP controled system and I would like to have a 5-way system to cover the audio spectrum.
The Daline and SOTA I build about 25 years ago but are still in use by my friends.
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