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
An externally hosted image should be here but it was not working when we last tested it.
We are sidetracking a bit, but I had a look at that crossover.
The trap on the bass operates at 1kHz and Q=2, the bass notch across the driver at 6khZ and Q=0.9. Looks like first order plus the effect of the trap to me, which is hard to do in your head on a 6.9 ohm Re bass!
The 4.3uF/0.25mH highpass rolloff looks around 5kHz, though I didn't calculate it. The bandstop around 2kHz as I thought. The LCR notch on Fs is really quite variable. I got 225uF, 0.59mh and 3.7 ohm on published specs at Fs 436Hz. Guess that will change as the Re=3 ohm tweeter breaks in.
Seems to me, we agree simpler filters would work just as well.
HeHe, back on-topic!
Fructose, I've got you your design for a nice, modern and tiny studio monitor in BBC tradition, Troels Gravesen's Studio 101:
Studio 101 Monitorcopyright 2009 ©
Decent impedance, stays above 6 ohms. Easy 13L cabinet (extendable if you want bigger) and room to tweak to your hearts content.
Drive units available and nice to boot: ScanSpeak 18W/8542-00 + SEAS 27TFFC.
Scanspeak is £130 6.5" paper unit. SEAS is a £30 vented soft-dome ferrofluid tweeter that I like a lot. Looks ace, and strangely old-fashioned!
Fructose, I've got you your design for a nice, modern and tiny studio monitor in BBC tradition, Troels Gravesen's Studio 101:
Studio 101 Monitorcopyright 2009 ©
Decent impedance, stays above 6 ohms. Easy 13L cabinet (extendable if you want bigger) and room to tweak to your hearts content.
Drive units available and nice to boot: ScanSpeak 18W/8542-00 + SEAS 27TFFC.
Scanspeak is £130 6.5" paper unit. SEAS is a £30 vented soft-dome ferrofluid tweeter that I like a lot. Looks ace, and strangely old-fashioned!
Jeff is very active on PE's TechTalk. A "Continuum" search there has over a hundred mentions and pics. His design is also being sold by Salk Sound and has a nice write-up.
Continuum home
Isn't funny (like always), people always start to like a certain speaker then think to clone the object but then wander around and build something completely different.
It is not an LS3/5A clone just because the cabinet has the same retro look
Actually, many things can be cloned from the LS3/5A, except the retro look that doesn't contribute to the sound character.
I hadn't appreciated what effort Jeff Bagby had put into recreating a modern LS3/5A, as it goes. The continuum kit looks very good down to the plastic woofer.Isn't funny (like always), people always start to like a certain speaker then think to clone the object but then wander around and build something completely different.
It is not an LS3/5A clone just because the cabinet has the same retro look
Continuum, Pr
He discusses it here:
The BBC LS3/5a's oddball crossover: bass from "nowhere" - Techtalk Speaker Building, Audio, Video, and Electronics Customer Discussion Forum From Parts-Express.com
As it goes (personal rant...) I hate bextrene cones. Dull as anything. Combined with a new metal dome which would probably make my ears bleed!
Troels' Studio 101 is his take on the Proac Studio 100 which is a hugely respected speaker too. Reflex is of course not outside the BBC tradition. The Spendor BC1 had a vent. It's always interesting to look at classic monitors and try and figure out why they were so good.
An externally hosted image should be here but it was not working when we last tested it.
We are sidetracking a bit, but I had a look at that crossover.
Seems to me, we agree simpler filters would work just as well.
Hi,
The crossover is a no compromise take on providing 2nd order L/R acoustic
responses without the assymetry usually used to take into account the
offset of the drivers acoustic centres, hence the delay circuit.
No doubt there are simpler x/o options, but they would not meet the
criteria laid out by Zaph. His write-up on the x/o is very comprehensive
and simpler filters simply won't "work as well" in this reference design.
Having said that the woofers only are $425 a pair, the best drivers
are expensive, and so it the complete speaker. It certainly isn't a
high value option. It would suit an OTT cabinet build.
Regarding the LS3/5A clones I'm not that keen on the Monacor
bass/mid, its a relatively cheap driver with limited Xmax. Zaphs
tests of the Aurum Cantus are pretty good for the drivers cost.
(Though his specs are way different to the manufactures.)
rgds, sreten.
I'd say given the cost of importing the Stirling Broadcast
stuff into the States, the "Continuum" is a better idea.
Last edited:
I have not actually heard Jeff's Continuum design myself. But several people whose opinion I value greatly have. And to a man, each said that they could live with it as their reference monitor. One actually designed an MLTL cabinet to extend the low end. And now that the kit is available at Meniscus for a very good price, it will be the next project I build. And if you are not a woodworker that can duplicate the cabinet, Jeff posts info on the cabinet builder that did his original. Add that to the fact that Jim Salk, who builds commercial designs in the thousands, would offer it as well, speaks volumes. If this design is what you are after, it seems a reasonable way to get there.
Have you checked out the Mandolin kit from Meniscus? I'm thinking thinking that might be the better overall speaker, but I'm looking for a speaker I can have fairly close to the rear wall (about 1 foot). How are the quality of the drivers?
Hi,
when you read a writeup that is mainly waffle because they don't want
to give away technical details you can't glean much. Personally I'd
never have a vented box that is -3dB at 42Hz and -6dB 4Hz lower.
A foot from the rear of the cabinet is doable with larger distances
to side walls. If you don't have a sub I'll repeat again floorstanders
are your best bet, and in terms of performance vs. cost if you are
building the cabinets, a 6.5"/1" two way floorstander tuned low
is hard to beat, unless it doesn't meet SPL requirements.
If you really don't know what you want its hard to to say go for this.
For a lot less than your $1000 budget I'd suggest :
https://sites.google.com/site/undefinition/diy/amiga
or
https://sites.google.com/site/undefinition/zx-spectrum
If you want a straightforward build regarding the cabinets for the budget.
They will for the money out perform LS3/5A clones inevitably, the latter
only really make sense if you must have or want to have miniatures,
which can sound fabulous within their inevitable limitations.
In the end you have to get your feet dirty and make up your own mind
what is likely best for you, nobody can tell you that, only point you in
the right direction given sensible questions.
Personally I prefer far more techinical detail than provided with the
Mandolins, the tweeter is good according to Zaph, and so is a
presumably similar but different SB bass/mid unit, but I'd want
to change the apparent bass end alignment.
rgds, sreten.
http://sites.google.com/site/undefinition/diy (see if nothing else, the excellent FAQs)
http://techtalk.parts-express.com/showthread.php?t=219617
http://www.zaphaudio.com
http://www.zaphaudio.com/ZA5/
http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://web.archive.org/web/20090902124715/http://geocities.com/woove99/Spkrbldg/DesigningXO.htm
http://www.rjbaudio.com/
http://web.archive.org/web/20090902202231/http://geocities.com/woove99/Spkrbldg/
http://speakerdesignworks.com/
http://www.htguide.com/forum/showthread.php4?t=28655
http://www.deadwaxcafe.com/vzone/david/david.htm
http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm
http://www.humblehomemadehifi.com/download.html
http://www.quarter-wave.com/
http://www.frugal-horn.com/
http://www.linkwitzlab.com/
http://www.musicanddesign.com/
Great free SPICE Emulator : http://focus.ti.com/docs/toolsw/folders/print/tina-ti.html
Last edited:
The LS3/5A was built for a specific purpose, monitoring of mostly vocal material and to be used in a small often mobile studio. It had floppy walls and a huge hump below 200 Hz and only someone like Ken Kessler would use it to evaluate the bass ability of Krell amps on
It had for its time a very nice midrange and that was what BBC needed in this application. The backmounted mid-driver and all the problem that this means is outdated. Nobody used bextrene drivers anymore and that is for a reason.
I have some KEF T27 tweeters and if I would find some B110 at flea market price I could try making LS3/5A as a hobby project. As I remember both the B&W DM12 and the KEF 101 sounded better at the time. And 30 years later current design from KEF, B&W, Dali and other sound much better so I really fail to see the point of spending a lot of money to just get LS3/5A sound???
I have "recreated" vintage designs as a fun project, but I have no illusion that this will give me the best sound for the invested time and money, but that is hardly the point of a hobby if it is DIY audio or fly fishing
It had for its time a very nice midrange and that was what BBC needed in this application. The backmounted mid-driver and all the problem that this means is outdated. Nobody used bextrene drivers anymore and that is for a reason.
I have some KEF T27 tweeters and if I would find some B110 at flea market price I could try making LS3/5A as a hobby project. As I remember both the B&W DM12 and the KEF 101 sounded better at the time. And 30 years later current design from KEF, B&W, Dali and other sound much better so I really fail to see the point of spending a lot of money to just get LS3/5A sound???
I have "recreated" vintage designs as a fun project, but I have no illusion that this will give me the best sound for the invested time and money, but that is hardly the point of a hobby if it is DIY audio or fly fishing
Hi,
One of the worst things that has happened to the british hifi press.
Pander to the gullible, never make any real sense, BS and be a snob.
Sadly, apparently, it works and he is "popular" with casual readers.
rgds, sreten,
In response to the original questions, I would recommend contacting Stirling Broadcast, whose contact info is given at their website.
I emailed them myself and received a very quick, complete, and courteous response from Mr. Stirling:
"[...]KIT 1:
Matched pair of Monacor drive units with custom neoprene gaskets and latest Stirling crossovers (for use with customers T27's).
£ £ 128.00
KIT 2:
Matched pair of Monacor drive units, Scanspeak tweeters, latest Stirling crossovers and a pair of baffles. Also included: Tweeter mesh grilles, all nuts/bolts/spacers, self adhesive felt squares, our custom neoprene gaskets for all four drive units
£ 268.00
KIT 3:
A pair of fully built & tested "complete matched pair baffle assemblies" (Monacor/Scanspeak/Stirling crossovers), ready to fit into the customers cabinets. These baffle assemblies will fit ALL LS3/5a cabinets from 1974 through to 2011. Top quality UK produced CNC machined birch ply baffles with velcro and tweeter felts fitted, mesh grilles fitted to the tweeters - just connect the flying leads on the crossovers to the rear connectors in your cabinets and screw the baffles down (self adhesive sealing tape included).
£ 328.00
KIT 4:
As per KIT 3, PLUS a pair of cabinets with glued-in rear panels, thin-wall 9mm ply construction...therefore "hybrid" reference cabs - (as used for Rogers 60th Anniversary model).
£ 488.00 to £ 518.00 depending on chosen veneer (Black Ash, Walnut, Cherry, Rosewood or Ebony).
Stirling MS-88 Loudspeakers
As KIT 4, but these are a pair of fully built and tested loudspeakers, fitted with bi-wire gold plated connectors, tygan grilles. Sold with TWO year warranty.
£ 568.00 to £ 598.00 depending on chosen veneer (Black Ash, Walnut, Cherry, Rosewood or Ebony)...."
Stirling manufactured the Rogers' 60th Anniversary LS3/5as, and they (Stirling) tell me that the MS-88 is exactly the same.
For what it's worth, I, myself, am planning on purchasing the Kit 4 -- assuming that they are exactly the same as the MS-88, down to the Tygan. I have a pair of very nice sounding Chinese LS3/5a variants, but, as an ex-Rogers owner, would like an official pair.
The info I received is the same as what was already cited at a certain Thai audio website.
I emailed them myself and received a very quick, complete, and courteous response from Mr. Stirling:
"[...]KIT 1:
Matched pair of Monacor drive units with custom neoprene gaskets and latest Stirling crossovers (for use with customers T27's).
£ £ 128.00
KIT 2:
Matched pair of Monacor drive units, Scanspeak tweeters, latest Stirling crossovers and a pair of baffles. Also included: Tweeter mesh grilles, all nuts/bolts/spacers, self adhesive felt squares, our custom neoprene gaskets for all four drive units
£ 268.00
KIT 3:
A pair of fully built & tested "complete matched pair baffle assemblies" (Monacor/Scanspeak/Stirling crossovers), ready to fit into the customers cabinets. These baffle assemblies will fit ALL LS3/5a cabinets from 1974 through to 2011. Top quality UK produced CNC machined birch ply baffles with velcro and tweeter felts fitted, mesh grilles fitted to the tweeters - just connect the flying leads on the crossovers to the rear connectors in your cabinets and screw the baffles down (self adhesive sealing tape included).
£ 328.00
KIT 4:
As per KIT 3, PLUS a pair of cabinets with glued-in rear panels, thin-wall 9mm ply construction...therefore "hybrid" reference cabs - (as used for Rogers 60th Anniversary model).
£ 488.00 to £ 518.00 depending on chosen veneer (Black Ash, Walnut, Cherry, Rosewood or Ebony).
Stirling MS-88 Loudspeakers
As KIT 4, but these are a pair of fully built and tested loudspeakers, fitted with bi-wire gold plated connectors, tygan grilles. Sold with TWO year warranty.
£ 568.00 to £ 598.00 depending on chosen veneer (Black Ash, Walnut, Cherry, Rosewood or Ebony)...."
Stirling manufactured the Rogers' 60th Anniversary LS3/5as, and they (Stirling) tell me that the MS-88 is exactly the same.
For what it's worth, I, myself, am planning on purchasing the Kit 4 -- assuming that they are exactly the same as the MS-88, down to the Tygan. I have a pair of very nice sounding Chinese LS3/5a variants, but, as an ex-Rogers owner, would like an official pair.
The info I received is the same as what was already cited at a certain Thai audio website.
Does anyone seriously think the LS3/5A had some sort of magic sauce poured on it? I really don't need a BBC license to get a speaker in their tradition. We know what the ingredients were. We've discussed most of the important design features. But might as well use modern components.
For my part, I prefer a little bigger box since I don't live in a rabbit hutch!
For my part, I prefer a little bigger box since I don't live in a rabbit hutch!
Yes, you are quite correct, of course.
The Stirling kits appeal to me as a less pricey way of replacing my old Rogers (purchased new at cost in 1984) with a new pair of speakers.
So, if, as I was told, the MS-88 is "exactly" the same as the Rogers 60th Anniversary, which bears BBC certification -- and which was much praised by Martin Colloms, as well -- then that is close enough for my personal listening purposes.
Again, Stirling's Kit 4 is presented as the same as the MS-88 but not fully assembled and "tested". In my view, that is rather analogous to the kit versions of the "official" speaker which I believe the BBC made available to their employees.
Just by way of explanation of my own circuitous logic....
Interestingly, Harbeth make a speaker that the BBC themselves buy from them, being an update of the original, It uses an improved cone and tweeter, but much the same neutrality and tight tolerances and a studio monitopr pedigree.
Enter the Harbeth Monitor 20 at an eyewatering £1200:
Harbeth UK
FWIW, the splendid Monitor 40 is about £6500.
Enter the Harbeth Monitor 20 at an eyewatering £1200:
Harbeth UK
FWIW, the splendid Monitor 40 is about £6500.
Rocelco had them a few years ago.
Since so many people are looking for replacements I sent them an e mail just to see if they were still available and they did not reply.
For the price better drivers can be purchased unless replacements are necessary for the Ls3/5a and Kef Constructor Kits.
Rogers LS3/5a Woofers & Tweeters
Since so many people are looking for replacements I sent them an e mail just to see if they were still available and they did not reply.
For the price better drivers can be purchased unless replacements are necessary for the Ls3/5a and Kef Constructor Kits.
Rogers LS3/5a Woofers & Tweeters
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!
I don't agree. The mylar domed T27 tweeter has several disadvantages (only high crossover frequency above 3K and very low efficiency) but the sonic quality is very hard to beat if one not listening with high sound pressure levels.
And even the KEF bextrene unit has several drawbacks, mainly the fact, that additional to the typical crossover network passive equalizer networks are necessary (then also low efficiency). Nevertheless outweigh the benefits, especially the low fres and the low temperature dependence so as low loss of the rubber surround (obviously very good recipe for the mixture).
I still have not found modern, currently available drivers with comparable rubber surrounds in this size (I know only few drivers with foam surrounds with similar behaviour).
OTOH - there are several vintage versions of the LS-3/5A and I know not all versions listed by post #63 about the German forum
LS3/5a in allen ihren Formen - Verstärker, Lautsprecher, Zubehör - Analog-Forum
But I know definitely, that the later versions, equipped with SEAS parts (Harwood/Harbeth P3ESR e. g.) no longer have quite the precision in sound from the old models. I guess, mainly cause ferrofluid inside of the tweeter and cause the low Qms values of the SEAS bass-mid transducers.
http://www.soundbysinger.com/UserFiles/image/Harbeth P3ESR close.jpg
I want also to know any currently produced drivers like the KEF B110A SP1057 about
http://homepage.mac.com/planet10/TLS/drivers/images/B110/B110_SP1057.gif
with free air resonence below 40 Hz by this size - addidional high quality mylar tweeters without ferofluid.
Thank you for your advices
Last edited: