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Offline najo49

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staight eight speakers
« on: September 26, 2012, 05:45:30 AM »
I just bought a set of the 8s,does anyone have any information on them. The tweeter was damaged in transit and I am wondering about the foil outer section. If this is torn is the tweeter ruined? It appears to me that there is a damping pad behind this foil section and another membrane behind that. I pushed the torn section of the tweet together and epoxyed over that. Also could anyone give me information on upgrades or other tweeters that could be used with this system. Thanks
Jann Olsen, [email protected]  Lowther medallion 2 with pm2a./ extended foreplay lll,/EROS phono /Grado ref/ SOTA star Vacuum SME V, /  45 amp direct coupled,c4s,mQ nickel  / paramour  2a3 w MQ iron /Original SEX monos /Jena Cables /heathkit wm6a/ proAc Tablette 50 sig , with push pull

Offline Doc B.

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Re: staight eight speakers
« Reply #1 on: September 26, 2012, 06:37:12 AM »
Upgrading to a Selenium ST324 is highly recommended. The woofer crossover remains the same, the tweeter merely needs a small cap in series. Sorry I can't remember the exact value, maybe 1uF?. Another option is an Aurum Cantus G2 ribbon tweeter. The crossover for that is much more complex.

For what it's worth I have a pair of Straight 8s with the Aurum Cantus Tweeters and crossovers that I need to sell to make room for some other things.
« Last Edit: September 26, 2012, 06:38:47 AM by Doc B. »
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Online Paul Joppa

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Re: staight eight speakers
« Reply #2 on: September 26, 2012, 07:27:26 AM »
It's probably a smaller cap than 1uF, maybe closer to 0.5uF. The cap affects the level, not the frequency response, for this particular tweeter (long story). Best would be to try a few to home in on the best balance.

The Climax article (on the Community page) shows a more developed crossover for the ST324. More valuable, look at teh physical modifications we developed which give that tweeter greater smoothness. This tweeter really wants to cross at 3200Hz, and the original Straight 8 was at 4kHz so you might augment the 8's woofer components by 25% to push it down. There is a circuit for the most recent Straight-8 crossover design under obsolete products - I don't recall that we ever sold that version, it was developed around the time the product was discontinued, and it's still at 4kHz - but it does show a Zobel.

There are a few generic domes at round 92dB sensitivity that might work as substitutes for the stock one - by using an 8 ohm tweeter with the 16 ohm woofer, you can get away with a less sensitive tweeter (the woofer array is nominally 96dB). If you can't find an exact replacement for the tweeter, then don't use the notch filter that is in the "most recent" crossover.
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Offline najo49

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Re: staight eight speakers
« Reply #3 on: September 28, 2012, 06:02:17 AM »
Doc, what do you want for your straight 8s?
Jann Olsen, [email protected]  Lowther medallion 2 with pm2a./ extended foreplay lll,/EROS phono /Grado ref/ SOTA star Vacuum SME V, /  45 amp direct coupled,c4s,mQ nickel  / paramour  2a3 w MQ iron /Original SEX monos /Jena Cables /heathkit wm6a/ proAc Tablette 50 sig , with push pull

Offline Doc B.

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Dan "Doc B." Schmalle
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