Hello, brand new here so please bare with me.
I have searched for this information on the The Unofficial LS3/5a Support Site.
Are there any new drivers being produced that have close specs to the currently out of production KEF B110 and T27?
If I was to buy a kit would I be able to use drop in replacements? Hard to believe some other manufacturer has not cloned these.
I have searched for this information on the The Unofficial LS3/5a Support Site.
Are there any new drivers being produced that have close specs to the currently out of production KEF B110 and T27?
If I was to buy a kit would I be able to use drop in replacements? Hard to believe some other manufacturer has not cloned these.
Jeff Bagby of PCD fame, designed the Continuum. The kit is available from Meniscus.
Continuum, Pr
Continuum, Pr
Attachments
The BBC LS3/5A was carefully equalised in the crossover for what is, by modern standards, a quirky heavy 5" KEF bextrene unit and a mylar domed T27 tweeter. I'd say the art has moved on a lot. 
Tweeters like the Vifa XT19TD00-04 soft dome are just SO much better. You have a huge choice of 5" units these days too. Kevlar or paper might be nice. Naturally cabinet size is dictated by woofer characteristics, but if you then apply baffle step correction and tweeter impedance equalisation, you should get something very BBC, as discussed here:
http://www.diyaudio.com/forums/multi-way/147632-classic-monitor-designs-13.html#post2891255
Baffle step calculation: Loudspeaker Diffraction Loss and Baffle Step Compensation Circuits
Impedance correction: Impedance Equalization (L-Pad) Circuit Designer / Calculator
One must move with the times!
Tweeters like the Vifa XT19TD00-04 soft dome are just SO much better. You have a huge choice of 5" units these days too. Kevlar or paper might be nice. Naturally cabinet size is dictated by woofer characteristics, but if you then apply baffle step correction and tweeter impedance equalisation, you should get something very BBC, as discussed here:
http://www.diyaudio.com/forums/multi-way/147632-classic-monitor-designs-13.html#post2891255
Baffle step calculation: Loudspeaker Diffraction Loss and Baffle Step Compensation Circuits
Impedance correction: Impedance Equalization (L-Pad) Circuit Designer / Calculator
One must move with the times!
I have owned the Spendor BC1 and have heard really many current production speakers. You can build lookalikes of such speakers, but nothing that is similar to bextren cones sonically. The best current production polymer cones IMHO are those from ATE, but as far as I know they are not available for DIYers.
http://www.a-t-e.de/
Polypropylene IMHO is no option.
http://www.a-t-e.de/
Polypropylene IMHO is no option.
I believe these drivers were intended to be a modern take on the KEF drivers. However I really doubt they will work as drop in replacements. It is very likely the crossover will need to be matched to the characteristics of the driver.
SPP-110/8 - Monacor hiFi bass-midrange speakers 60Wmax 8Ω - Europe
http://www.europe-audio.com/Product.asp?Product_ID=3665
I have not tried these so can't comment on if they are any good but they are not that expensive if you wanted to have a go.
Regards,
Andy
SPP-110/8 - Monacor hiFi bass-midrange speakers 60Wmax 8Ω - Europe
http://www.europe-audio.com/Product.asp?Product_ID=3665
I have not tried these so can't comment on if they are any good but they are not that expensive if you wanted to have a go.
Regards,
Andy
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Very nice. Exactly what I'm looking for. Do you know of any other pictures of that one. I could not find any specific threads.
Thanks. Any specific kits, or designs with part lists you can recommend?
Hi,
Why would you want to clone drivers, especially the B110
that have known issues and known consistency issues ?
Why would you build drivers you know you have to correct
in the x/o ? (This applies to most bextrene cone drivers.)
and why build drivers with low power handling ?
You can get 3/4" tweeters that easily outperform the T27.
Although it has a cult following, the LS3/5A is not a particularly
good domestic loudpeaker*, it ended being relatively poor value,
and still is if you pay the going rate for vintage drivers (a lot
of which are not the correct spec) and build cabs and x/o.
a fully working, ful spec pair of L3/5A's would be a nice thing
to own, a bit of history, but they are not cheap. It is not worth
the effort IMO to try and clone them, given other options.
I've not seen that Continuum kit before, TBH it looks quite good.
The fat bass is replicated, the rest of it looks good to me.
rgds, sreten.
* for its cost.
My interest in the LS5/3A comes from in store audition (Rogers) about 22 years that left a great impression. I recently read some articles about them (and their cult following) that spurned my re-interest. That is how I ended up at this discussion board.
I was not aware of any this. Any suggestions for a 2-way bookshelf for roughly under $1000 USD in parts?
I found this info on the Asterion, but a quick search tells me that Vifa XT18WH 6.5"might not be available anymore.
http://www.rjbaudio.com/Asterion/asterion.html
I do have the woodworking skills and tools to build great cabinets, so I just need a great set of plans and part list for a set of currently available drivers. I have built one set of speakers from scratch many years ago from my own calculated design with mediocre results.
Thanks for the help!
I was not aware of any this. Any suggestions for a 2-way bookshelf for roughly under $1000 USD in parts?
I found this info on the Asterion, but a quick search tells me that Vifa XT18WH 6.5"might not be available anymore.
http://www.rjbaudio.com/Asterion/asterion.html
I do have the woodworking skills and tools to build great cabinets, so I just need a great set of plans and part list for a set of currently available drivers. I have built one set of speakers from scratch many years ago from my own calculated design with mediocre results.
Thanks for the help!
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Please ignore earlier post which points to the wrong Monacor drive unit. This kit from Stirling has modern replacement drive units and a crossover to match. It even comes with the baffle so all you need to make it the rest of the box to match.
Complete Replacement LS3 5a Driver Kit Pair items in Stirling Broadcast LS3 5a Shop store on eBay!
I have no experience of these parts so can't comment on how well the work.
Regards,
Andrew
Complete Replacement LS3 5a Driver Kit Pair items in Stirling Broadcast LS3 5a Shop store on eBay!
I have no experience of these parts so can't comment on how well the work.
Regards,
Andrew
the LS3/5 were a monitoring speaker. Probably only for nearfield use.
As such they were intended for helping to find errors in transmission quality.
That made them fairly good as not loud level reproduction speakers in a quiet domestic environment.
They certainly were not made for a Christmas party, nor the kids' friends coming round.
As such they were intended for helping to find errors in transmission quality.
That made them fairly good as not loud level reproduction speakers in a quiet domestic environment.
They certainly were not made for a Christmas party, nor the kids' friends coming round.
If you are interested the original white paper by the BBC is still available:
http://downloads.bbc.co.uk/rd/pubs/reports/1976-29.pdf
Before people believed speakers were a black art and data was actually published.
Regards,
Andrew
http://downloads.bbc.co.uk/rd/pubs/reports/1976-29.pdf
Before people believed speakers were a black art and data was actually published.
Regards,
Andrew
I enjoy reading articles by BBC engineers, and studied that BBC LS3/5Aarticle in detail. They really know their stuff and apply a few old radio frequency techniques when appropriate. Morgan Jones was a BBC sound engineer, and his little Arpeggio loudspeaker is a masterclass in optimising a design for a high source impedance SET valve amp.
http://www.diyaudio.com/forums/diyaudio-com-articles/158899-arpeggio-loudspeaker.html
Modern is done very well by Troels Gravesen, and he tells you ALL about it:
DIY Loudspeaker Projects Troels Gravesen
The Vifa section is interesting for this affordable reflex mini speaker, for instance, albeit impedance plummets to 4 ohms at times:
Vifa PL14WJ-
Just bear in mind these tiny speakers are great on vocals, but really don't have much bass, though you could fiddle with that a bit.
http://www.diyaudio.com/forums/diyaudio-com-articles/158899-arpeggio-loudspeaker.html
Modern is done very well by Troels Gravesen, and he tells you ALL about it:
DIY Loudspeaker Projects Troels Gravesen
The Vifa section is interesting for this affordable reflex mini speaker, for instance, albeit impedance plummets to 4 ohms at times:
Vifa PL14WJ-
Just bear in mind these tiny speakers are great on vocals, but really don't have much bass, though you could fiddle with that a bit.
Hi,
IMO the best 5"/1" design available is :
Zaph|Audio - ZD5 - Scan Speak 15W8530K00 and Vifa XT25
Note that high quality small speakers don't belong anywhere near bookshelves,
they must be stand mounted away from walls, consequently the floor standing
version makes a lot of sense given the cost of high quality good speaker stands.
Its not the highest value, but I reckon it is the best for a no sub set up.
One could go somewhat more OTT on the cabinets, depending on skills,
time, patience and cost. These two sites take cabinets very seriously :
DIY Loudspeaker Projects Troels Gravesen
Humble Homemade Hifi
A boat shaped cabinet is an obvious improvement to be made.
Maintaining the front baffle specifications as stated of course.
rgds, sreten.
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Which, of the very many projects on Troels' site, are we looking for in the context of this thread?
i have a friend who always wanted a set of LS3/5A (his main speakers are a set of stacked quads, and his second srting areSpendor BC1 he bought new).
He bought a set from the local emporium, that turned out to have dented tweeter (with no covers), the wrong woofer, the wrong crossover, the wrong grills and not all the binding posts the same... the boxes and grill frames original.
I restored them, new tweeter (thanc Jeff), proper B110 (matched) and XOs from Falcon that i got in the UK. I had the proper grill material salvaged frm some Tangets, i swapped a set of working VIFA tweeters for a set of grills off of dead Celestion HF2000, and upgraded the binding posts.
Restored head to head against a set of mFonken, they trailed badly for domestic use (can'tcomment on their use in a BBC broadcast van). There are any number of my milliSize boxes that should be more suitable for the given use and at a fraction of the cost.And if i can do it, there have to be lots of other candidates for better value & performance, i'm sure many alteady linked qualify.
dave
If you liked the sound of the LS3/5A my guess would be that the Zaph Audio design would be more of a modern take on that than the MFonken (Which is based on a full range light weight driver). Zaph's designs are very well researched and it is well worth looking through his website to see his thought on speaker design.
But if you really liked the very controlled sound of the LS3/5A the kit from Sterling is probably the closest you will get with easily available parts.
Regards,
Andrew
But if you really liked the very controlled sound of the LS3/5A the kit from Sterling is probably the closest you will get with easily available parts.
Regards,
Andrew
The LS3/5A was a tiny 5L of birchwood ply closed box, bringing the benefit of low distortion due to low cone excursion and an undemanding high load impedance. One of the things to consider is what you will be driving a modern clone with. Presumably a low output impedance transistor design. I see signs that the BBC design is optimised for this in the asymetric capacitor values in the high pass:
Spendor builds opted for 1.5uf/0.3mH/5.03uf for C2/L3/C4 with a standard inductor in the 3rd. order highpass filter and a resistive pad on the tweeter. The autotransformer was a tricky item to build within spec. R3 of 82 ohm goes without the auto, it was just to stop a HF ringing.
The 500Hz baffle step compensation on the lowpass will actually slightly modify the values in the lowpass filter, but that is simply a matter for calculation using older radio techniques where source impedance is a consideration.
The Zobel network on the tweeter is something you can take or leave, it has little affect on the HP filter, but IMO smooths the HF performance. The R2/L2/C5 trap is rather specific to the peaky B110, and would be simplified on a modern design.
Where this is leading, is if you want to clone this design in a modern context, I'd say go infinite baffle with modern drivers. 2nd order with baffle step on the LP, 3rd. order on HP with attenuation pad and Zobel impedance matching. It would be fun to analyse that HP filter and see if it's nearer butterworth or bessel slope. But I'm not gonna do it, it's your baby!
I'd certainly use a bigger cabinet for a bit more real bass. Mainly deeper, keeping the same front dimensions.
Ooh, FWIW, that Zaph audio design has the weirdest bandstop filter on the treble and some highly specific total Vifa XT impedance matching. What's that all about? Good or just unusual?
An externally hosted image should be here but it was not working when we last tested it.
Spendor builds opted for 1.5uf/0.3mH/5.03uf for C2/L3/C4 with a standard inductor in the 3rd. order highpass filter and a resistive pad on the tweeter. The autotransformer was a tricky item to build within spec. R3 of 82 ohm goes without the auto, it was just to stop a HF ringing.
The 500Hz baffle step compensation on the lowpass will actually slightly modify the values in the lowpass filter, but that is simply a matter for calculation using older radio techniques where source impedance is a consideration.
The Zobel network on the tweeter is something you can take or leave, it has little affect on the HP filter, but IMO smooths the HF performance. The R2/L2/C5 trap is rather specific to the peaky B110, and would be simplified on a modern design.
Where this is leading, is if you want to clone this design in a modern context, I'd say go infinite baffle with modern drivers. 2nd order with baffle step on the LP, 3rd. order on HP with attenuation pad and Zobel impedance matching. It would be fun to analyse that HP filter and see if it's nearer butterworth or bessel slope. But I'm not gonna do it, it's your baby!
I'd certainly use a bigger cabinet for a bit more real bass. Mainly deeper, keeping the same front dimensions.
Ooh, FWIW, that Zaph audio design has the weirdest bandstop filter on the treble and some highly specific total Vifa XT impedance matching. What's that all about? Good or just unusual?
Ooh, FWIW, that Zaph audio design has the weirdest bandstop filter on the treble and some highly specific total Vifa XT impedance matching. What's that all about? Good or just unusual?
The delay circuit on the tweeter (XT25) of the ZD5? I don't like such circuit. If you had access to a lot of drivers, why not choose drivers combo that doesn't require complex filter? Best speaker always start with best matched drivers.
Bit off-topic, but, a strange beast really!
An externally hosted image should be here but it was not working when we last tested it.
Zaph is introducing a midpass or midstop filter around 2kHz into the high pass element. L11, R12 and C10 are just correcting impedance for the Fs resonance at 500Hz, which is no bad thing, and will improve power handling. The midpass is a nice touch in 2nd order active filtering and might get you an overall allpass response with inevitable group delay, if you know your transfer functions which have 1, s and s^2 elements in the numerator and denominator where s is the midpass element, but must do HORRIBLE things to impedance and matching with non-ideal loads in passive filtering, which is why he's put 5 ohms at the HP input. Wouldn't fancy it myself, but will mull it over.
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Wouldn't fancy it myself, but will mull it over.
Imagine that if all out of phase response between woofer and tweeter can be solved using the delay circuit without ill effect, then it will make speaker designers life a lot easier. But I have tried it and decided not to use it. Prefer to find the in-phase response without the delay circuit.
Well, I know, a first order on the woofer will give a very good sound, and you may want to "sacrifice" the tweeter for that
