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[Hackenberg]

Jeg har haft nogle sæt. Uanset finer på siderne er fronten altid med folie??????? Fremragende basser med SD-system (kobber-kappe).

[Struktør]

Det ser hamrende godt ud, og de forskellige anlæg misklæder absolut ikke dine skænke
Samtidig er stilen enkel og ligetil... Man undres over de kvinder og mænd, der ikke ser disse indretningsmuligheder, med vellyd i tilgift...

Mvh
Birger

[Tube mania]

Mange tak...ja jeg synes også de er ganske pæne

[Tube mania]

Sikken historie...man bliver helt rundforvirret af at læse den.

http://www.cfuttrup.com/history/scan-speak.html

Uden relation til ovenstående er dette også interessant.
'
http://www.nutshellhifi.com/library/spe ... sign2.html

Bextrene Midbass

This is an acetate plastic derived from wood pulp, and is typically damped by a layer of doping material on the front of the cone to control the strong first resonance it displays around 1.5 kHz. It was originally developed by the BBC in 1967 to replace paper with a more consistent and predictable material for monitoring purposes. It came into widespread use in the early Seventies, with the typical audiophile speaker using a 8" KEF or Audax Bextrene midbass driver with an Audax 1" soft-dome tweeter.

The BBC-derived designs always employed notch-filter equalization to flatten the Bextrene driver in the midband; the most famous (or infamous, depending on whether you were the listener or the designer) driver was the KEF B110 used in the BBC LS 3/5a minimonitor. Not everyone knows that this speaker, which is legendary for its sweet midrange, employs a deep notch filter with 6dB of attenuation at 1.5kHz to correct the B110.

Over time, Bextrene has been replaced by BBC-developed polypropylene, which gives much flatter response, does not require a layer of doping material, and provides a 3-4 dB increase in efficiency due to the decrease in cone mass. Bextrene is now considered an obsolete material by nearly all speaker designers.

Strengths are: Consistent batch-to-batch, excellent potential imaging (by mid-Seventies standards). Inner resolution higher than many paper cones.

Weaknesses are: Very low efficiency (82-84 dB at 1 meter), requires a strong notch filter in the midband, a "quacky" coloration by modern standards, sudden, unpleasant onset of breakup at not-so-high levels, and numerous resonances at the top of the working band.

Best Examples are: None. Modern designers are not willing to tolerate the low efficiency and the complex notching and shelving equalization required to make these drivers acceptable. Although some traditionalists revere the KEF B110 used in the Rogers LS 3/5a, the uneven response of this driver requires the LS 3/5a crossover to be very complex. Having worked with the B110 for many years, I feel the modern Vifa P13WH-00-08 is superior in every way.

Polypropylene Midbass

This material was developed and patented by the BBC in 1978 (my dates may be off) as a replacement for Bextrene. Since it is intrinsically self-damping, a correctly designed polypropylene driver is capable of flat response over its working range without little or no equalization. In addition, they typically attain efficiencies of 87 to 90 dB at 1 meter, which is a major improvement over Bextrene.

This material has become nearly universal, since it requires a minimum of hand treatment to assemble a loudspeaker - the only difficult problem was finding the cyanoacrylate adhesives that would stick to a slick material like polypropylene. That problem was solved in the beginning of the Eighties.

As with paper, this cone material is used in speakers ranging in quality from mass-fi rack-stereo systems to the first-rank ProAc Response series. The cone profile, termination at the edge of the cone, and additional materials added to the polypropylene mix strongly determine the ultimate quality of this type of driver.

Strengths are: Very flat response if correctly designed, very low coloration, good impulse response, gradual onset of cone breakup, good efficiency, and a crossover that can be as simple as one capacitor for the tweeter. The best examples can be as transparent as the best paper-cone drivers, which is a very high standard.

Weaknesses are: Not quite up to the standard of transparency set by the rigid-cone class of drivers and the planar electrostatics. Many poly midbass units do not mate well with the popular metal-dome tweeters, with differences in resolution that can be obvious to the skilled listener. Not a good choice for woofers 8 inches or larger unless the polypropylene is reinforced with another, more rigid, material. Woofers 10" or larger are better served by stiff paper or carbon fiber.

Best Examples are: The Scan-Speak 18W/8543 7" midbass, as used in the ProAc Response Threes, is probably the finest polypropylene driver in the world.

Another closely-ranked contender is the Dynaudio 17W-75 Ext. 7" midbass, as used in the Hales System Two Signature.

The Vifa P13WH-00-08 5.5" midbass/midrange unit is a superb performer, well suited for midrange or minimonitor use. It is unique in having a textbook-flat midrange combined with a completely smooth Bessel 2nd-order rolloff. I use these drivers in the Ariels, and I’m very pleased with the results. The Vifa P13WH does not have the typical "poly" sound, sounding much more like a top-rank paper-cone

[Tube mania]

Så er der kommet nye kommoder i stuen. Kun en er på plads lige nu og endnu ikke tilsluttet. Det er meningen den lille Luxman SQ38 skal være drivende kraft til dem. Jeg antager at med den følsomhed de har spiller den som en 300W forstærker

[ferr31]

Du manglede da også
Hold kæft de ser godt ud, jeg må snart forbi en tur, hvis du giver en kop kaffe.

[Tube mania]

Jada...jeg er jo næsten klar :)

[pqrannes]

Så er der kommet nye kommoder i stuen. Kun en er på plads lige nu og endnu ikke tilsluttet. Det er meningen den lille Luxman SQ38 skal være drivende kraft til dem. Jeg antager at med den følsomhed de har spiller den som en 300W forstærker

Smukt! Sad faktisk og savlede over sådan et par på nettet igår (har noget med store kasser for tiden). Spændende at høre hvordan du synes de lyder og måske høre dem en dag.

PQR

[Tube mania]

Ja..det må du

Nå..fik jo lavet nogle kabler og fik startet op med Jimmy Schmidt ..uha..det var en krads omgang. Det var en lille rørforskrækker på 5W der havde trukket dem før og der var bålet næsten helt op for mellem og dis kontrol på dem. Det fik jeg på plads og så Mark Knopfler..On every Street på. Så lød mere henaf 'nutella'. Der er noget at lege med

[Tube mania]

Lidt nyt og gammelt..mest gammelt. Men det spiller utroligt fast og kontant med flot mellemtone og sprød diskant. Især godt klaret af næsten 50 år gamle højtalere..stadig bløde og fine i ophæng.

[Dan63]

Hej Tube mania

Hvad er det så for nogle højtalere du har anskaffet dig?
Både de robuste og "kommoderne". :)

Mvh Dan

[Tube mania]

Hej Dan
Jeg har 2 sæt i stuen. 1. Altec Lansing model 19 (komoderne), 2. Arena HT25, den var Arena's topmodel inden det brændte i 1974. De nåede at sælge den i Amerika og Tyskland. Herhjemme er der kun få sæt og jeg har været så heldig at finde et. De indeholder 2 B139 basser + slave og 3 B110 mellemtoner samt 4 T27 diskanter. De lyder fantastisk, men kan ikke spille med front-stof og den originale receiver Arena T9000 yder dem heller ikke retfærdighed. Men af med frontstoffet og en Sansui BA-F1 til at trække dem ..så er de intet mindre end fremragende.

[Dan63]

Hej Igen.

Tak for info!

Det er rigtigt nu kan jeg huske at du beskrev at Arena HT25'erne havde en nedadvendt slave.

Altec 19'erne kan de hamle op med Arena'erne?

Mvh Dan

[Tube mania]

Undskyld det sene svar Dan, men her har været lidt hektisk. Mht højtalerne..så er de så forskellige at de ikke er til at sammenligne. Noget musik lyder bedst på det ene sæt og noget andet på det andet. Arena'erne har nok den mest stuevenlig hygge lyd og Altec'erne er mere til koncentreret lytning, men begge har stort potentiale. Jeg ville nødig undvære nogen af dem.

[Tube mania]

Et billede siger mere end ord...siges det...så her er et billede