Čime se zanimam... (ovih dana )

[prophet]

U pravu si, briši ovaj offtopic.

[ZZZ]

Evo malo istorijata iz prve ruke

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About Westrex speakers by Dave Fenner

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"...First in reply to others about origin, I should have said, it is fact that all the 2080 and 2090 drivers had transfer label 'Made in England'. I dont know where or by whom, maybe Vitavox or BTH or even Goodmans?

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"...The point is that this is not a bare diaphragm. Be that as it may, fact is Westrex's unit rating was 30 watts continuous and it is clean all the way. I suspect it would bust without the 'book' but wouldn't want to risk trying it (around £50 for new one, still available from Lansing!). I can assure you acoustic output is plenty high enough in a small hall (but probably wouldn't survive for todays pub gig levels)."

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"Westrex Book Radiator

I was a field engineer at Westrex, my patch was NW London. I left to set up my own company and Westrex were my main Distributor, so I was often in and out of the Works at Coles Green Road. The following paragraph is not for the squeemish.

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Most UK cinemas using Westrex sound and projection equipment were on a lease plus service contract, the gear was owned by Westrex. During late 60's cinemas were fast being converted to multiples, bingo halls or bowling etc, so masses of equipment was being removed. Having no storage space they put large skips behind the works. These were daily filled with 2040 40 watt tube amps (best ever), 2080 bass drivers and 2090 drivers and horns, and sold as scrap. Bass bins were broken up on site. Crying is allowed.

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One day when visiting I saw lying by the skip a 2090C driver complete with Book Radiator. I grabbed it and remarked to the warehouse manager (Mr Bill Diamond) 'pity there is not a pair'. 'Wait',we are having a clear-out' he said and went inside and returned with another, which was obviously a prototype, having a rough looking makeshift bracket for mounting but otherwise identical.

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I beleive these speakers as shown here were intended to superceed the original Acoustilens model, I cannot be certain but few if any were sold, in which case they are extremely rare. The only ones I knew of were owned by a very few of my fellow engineers. The guys that had them were the cream of the West End sound men, like Gorden Isaacs and Billy Bell. I heard them on a system consisting of a pair of 2040's, a Decca FFSS cartridge and tone arm. I never heard before or since such gorgeous quality from vinyl. But I must say the best systems I ever heard were the circa 1954 4 track mag Cinemascope movies with 3 Westrex bins with cellular horns. Its all gone backwards since. It is no surprise to me that efficient speakers sound far better, its the tight control by the huge magnets and small accurate gap, and stiff ouput of the transfomer coupling, damps overshoot and flapping around.

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Back to the Book Radiator; I do still own the original prototype. At one time I pondered copying the perforated sheild and the Book 'pages' and offering them as conversion kit for 2090A. Too old to bother now. I am not familiar with the type number 2390, my memory is fading but as I recall the original horn driver was 2090A (24 ohms) and 2090C (15 ohms and no phase plug) but I could be wrong.

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As you may know, if you put LF power to an unmounted bass driver, no loading to control it, it will likely bust the spider and surround. An HF pressure driver with no horn will do the same, fly to bits. Thats why they are tightly bolted up with a gasket. Failure of these drivers is often result of blown seal. If HF diaphragm was left bare with no horn load it would only be able to work at low level without damage. The name Book Radiator is the clue; you cannot slam shut a book however hard you push, you are working to push out the air. Thats what the leaves are for, to load the thing so it has some work to do. The perfotated shield holds the leaves in place and restricts overshoot.

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This may be likely reason crossover frequency of these units was raised to 1000hz (Acoustilens was 675 i think, cinema horns were 500)."

[ZZZ]

u tim kabinetima su bile identicne sekcije skretnice za LF WE 2080E i  i HF WE2390A

i to 8uF paper in oil + 5 - 5.13 mH kalem i neverovatnih oko 1 om Rdc, sto je jako lose...

takodje klimav i loseg Q faktora... Kondenzatori stari i na izdisaju mada naoko deluju kao novi...

driveri su 15 oma (Rdc 12 oma cca.)

[Zvu]

U kojim hornama je meren taj WE kompresioni drajver?

[ZZZ]

nemam horne za njih, tu je isao onaj set lensesa ispred...

velike su membrane skoro 11cm precnik

i horna bi bila ogromna za njih

ovo sam izmerio na podu 1m i mikrofon na podu

sa tepihom, da bi se izbegle refleksije barem sa jedne strane

mislim da je bilo bez krilaca ispred i da je komora bila zatvorena i "dampirana"

sunđerom starim 50 godina koji je poceo da se raspada... Uklonjeno i otvorena komora.

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[Zvu]

Odlično to izgleda.

[ZZZ]

pa verovatno zato sto su originalne WE membrane sa kalemom?

Ali samo izgleda... Kad bi se slusao grafik, ihh

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to bi jednog dana bili dobro uraditi neki karlson coupler za njih malo veci ili neki plici WG

nemam pojma.

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ali nije lose to sto su membrane velike, pa recimo sa nekom malom masom i manjim signalom

mozda pokusati da se izmere TS parametri?

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Za sada mi je to sve u nekoj najmanjoj mogucoj formi OB i sve je jedno na drugom

tako da ne zauzima puno povrsine poda.

dole su 2 x 2080E u U frameu (linkwitz orion style) i neka kvazi 24db od po 3 oma total DC sa pasivnim shelf netom ispred...

gore su 2 x 2390A isto otvoreni svski isped ima lenses a iza karlson i pod 180de obrnutih faza isto kao i basovi

centralni RCA LC1A (samo LF unit, HF otkacen...) sa po 6 db prirucnom skretnicom citaj neispravni rezim rada... ha ha

daje koliko toliko dobar rezultat

visoki nemaju zrno kompresije imaju neki čudan smek ali ne onaj PA

ali jednostavno i pored 6db atenuacije preuzimaju stvar i to je to.

tako da mora tu nesto drugo...

visoki si ima solidan rezultat

[ManicP]

Ufatio me sinoćke neizdrž, morao sam da šrafim...

 

 

 

Skretnica: gornja 12ica full range + 3uF na horni, donja 12tica kao bas helper preko Zvuletovog torobara (krofna na dnu kutije) i još nekog induktiviteta što sam našao po kući (cirka 10mH) i tweakovano zelenim jastučetom za prirodniji zvuk.

Fali mesa basu al sviri muziku  

 

Merenja nemam. I onako samo kvare sreću

'Teo sam al sam naseko štrudle s makom i udobno se zavalio.

 

[Zvu]

opaaaaaaa !!!!!!!!!!

[Doktor]

Merenja nemam. I onako samo kvare sreću

'Teo sam al sam naseko štrudle s makom i udobno se zavalio.

[grau.]

ne znam sta dobijate kada slusate kompresioni drajver bez horne. koliko je grlo tog westrexa? kapiram da bi se nasla horna za probu na forumu. takodje mi nije jasno kako se odziv u visokim od 10k kod ZZZ podigao na skoro pa 20k kod propheta. ste radili neki EQ?

[Zvu]

Kompresioni drajver kom je skinuta kompresiona komora može da radi kao neki veliki kalotni visokotonac.Bar mi tako deluje.

ne znam sta dobijate kada slusate kompresioni drajver bez horne. koliko je grlo tog westrexa? kapiram da bi se nasla horna za probu na forumu. takodje mi nije jasno kako se odziv u visokim od 10k kod ZZZ podigao na skoro pa 20k kod propheta. ste radili neki EQ?

Kod ZZZ-a svira WE, a kod Propheta svira Selenium D220ti u HM17-25 horni.

[grau.]

cek, pitao sam za plot koji je prophet postavio, ima neki drajver koji tamo cepa od 300-400hz pa do jedno 17-18k dosta ravno, mislim da rece da je to westrex

[Zvu]

Grafik u postu 585 je WE, a onaj u 623 je Selenium D220ti.

 

Oba je postavio Prophet.

[grau.]

585, na to sam mislio. sad vidim da pise da nije njegov:)

[ZZZ]

@ Anubis

sa posta 585 je WE 2390A bez horne.

[Eci]

Vratio sam drivere - sviraju mnogo zabavno 

 

 

[grau.]

omnidirekcionalno ludilo

[Eci]

e baš to

 

[Zen Mod]

Dynacord Mosquito takodje predstavlja izvanredno zabavnu lutiju

[zocky]

 

 

ovih dana crtam neke pcb zezalice...

 

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nema veze sa hifi i baš mi teško ide

 

U nastavku se "zanimao" Milan-pcb :

 

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... sada samo da potpalim letkum i skinem ovo sa dnevnog reda

 

Završena gradnja prototipa "info-panela"...

 

 

Pored standardnih opcija/funkcija, zamišljene su neke dodatne mogućnosti u sprezi sa android telefonom... videćemo šta će od svega biti na kraju

[Eci]

Posle Bose 901 došao na red i grau-ov 3012 sa SPU , odredio sam težinu dodatnog tega pomoću olova za pecanje ( ništa bez carp systema )

Težina od 80gr je optimalna

Dodatni teg će se raditi od mesinga/bronze ili prohroma , sve zavisi šta bude grau našao od materijala