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Xover caps


real1shepherd

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I've been gone a loooong time....sorry about that. FWIW, still listening to Masonite LA's in the 'double Advent system'. I replaced the original tweeters with the newer 1" black domes a long time ago. One suspect (ebay) tweeter burned out its voice coil. So that put me back in the market for a matching pair. I won two from a Advent 5002 set. Soooo...two will say Advent Corp/Cambridge, Mass and the other two say nothing-I suspect they originally came from Simply Speakers.

OK...I'm not trying to make a perfect set of Advents, although I heartily applaud all that Pete B has done and researched over the yrs. :lol::D At some point, I will invest in some horribly expensive pair of Something or Other. For now though, since Layne Audio is no more, I need some poly caps in the Xovers. Can I just find some quality poly caps and substitute the same value as the originals? Remember, I'm not trying to make a silk purse out of a sow's ear, just something that will assimilate well with the newer, 1" dome tweeters.

Kevin

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I've been gone a loooong time....sorry about that. FWIW, still listening to Masonite LA's in the 'double Advent system'. I replaced the original tweeters with the newer 1" black domes a long time ago. One suspect (ebay) tweeter burned out its voice coil. So that put me back in the market for a matching pair. I won two from a Advent 5002 set. Soooo...two will say Advent Corp/Cambridge, Mass and the other two say nothing-I suspect they originally came from Simply Speakers.

OK...I'm not trying to make a perfect set of Advents, although I heartily applaud all that Pete B has done and researched over the yrs. :blink::D At some point, I will invest in some horribly expensive pair of Something or Other. For now though, since Layne Audio is no more, I need some poly caps in the Xovers. Can I just find some quality poly caps and substitute the same value as the originals? Remember, I'm not trying to make a silk purse out of a sow's ear, just something that will assimilate well with the newer, 1" dome tweeters.

Kevin

There is nothing wrong with doing a restoration and modification like that. I heard some person refer to such activity as "restification".It's interesting that you mentioned the Advent 5002 _ the "Large Advent" of the 80s. I got a pair of those for next to nothing at a garage sale knowing that they weren't working properly. Mine have that same 1" dome tweeter. The problem with mine was that the woofers were gonzo - bad surround on both of them (which was normal for them) and one woofer was blown. When I took the woofers out of the box, I discovered that the woofer cut out was 10 1/2" in diameter and this enclosure was made out MDF instead of particle board. Seeing that I had plenty of MDF on hand and also a couple of glass pie plates that were 10 1/2", I put my woodworking skills to use and made an insert for the woofer cut outs. I then cut out a 9" hole in the inserts. I installed these inserts and converted these "Large Advents" to accept normal 10 inch woofers. After carefully sanding and finishing, I installed some normal/standard 10 inch woofers that I had on hand and made some slight _ meaning, I didn't have to do very much _ adjustments to the crossover. Presto, restored/modified Large Advents that, to me, sound better than many of the originals that I remember hearing over the years. Again, there is nothing wrong doing a "restification" on a speaker.

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Except that if anything, the original Advent woofers Kloss designed are its strong suit....he got those correct. It's sacrilegious to do anything to them except refoam. :D There are ways to brace the original cabinets, change the crossover design and re-tweeter. There are even posts in here about using insulation rather than foam. Both sets I have are early enough that they have the insulation and then that cheesecloth looking stuff as a barrier.

These new dome tweeters sound different than the originals...if anything, a bit harsh. If memory serves me, I've been told that using poly caps of the same tolerance as the originals, will improve the sound. I just wanted to verify that again. I really don't have any interest in going further than that, as I stated. There are some fabulous speakers on the market today...if you can spend the money. Or...if I was staying 'retro', I'd get some 70's Bozak Concert Grands and rework the Xovers. Few speaker ever came close to those; fantastic sound, fantastic inventor.

People have forgotten over time, just how many LA's were sold. My first set were bought in '72 when I was still in college. About twelve yrs ago I had a tweeter cutting out.....or so I thought. Having nothing to lose and thinking that parts were cheap, I decided to dissect the tweeter and see its problem. There was nothing wrong with it, but I did manage to wreck it permanently (that's what initiated the quest for the newer black, dome tweeters-which Advent Corp was selling as replacements). What I eventually found was that one of the cap leads had never been soldered to its terminal; the lead sometimes made contact, sometimes not. The mark of a true mass-produced speaker with indifferent build quality! :blink:

Kevin

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Hehe. Sorry, don't mean to laugh at you but I've been there. :D

Rule #1. ALWAYS check crossover before assuming driver is bad and then ripping said driver apart never to be operable again.

Doug

That's OK, it IS funny now. :D It was a 'duh' moment to be sure, but it did lead me to the road of replacing all the tweeters with the new style, black domes. Soooo....about my original query.....?

Kevin

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That's OK, it IS funny now. :D It was a 'duh' moment to be sure, but it did lead me to the road of replacing all the tweeters with the new style, black domes. Soooo....about my original query.....?

Kevin

Suggest you look at Dayton 1% poly caps available from Parts Express

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Oh yeah. Yes, you can substitute almost any type of capacitor as long as the values match.

I have a tendency to be a purist here though because I want to ensure the original sound is preserved. So I would use original style non-polarized electrolytics.

How much a difference do other types make? I don't know myself because I have never replaced any in my four pairs (all from later runs with the 16/8 uf combination).

I have been thinking of at least removing them and measuring but the speakers sound good.

I have refoamed all of them using the real floppy surrounds which is the type to use with AS systems.

Doug

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Oh yeah. Yes, you can substitute almost any type of capacitor as long as the values match.

I have a tendency to be a purist here though because I want to ensure the original sound is preserved. So I would use original style non-polarized electrolytics.

How much a difference do other types make? I don't know myself because I have never replaced any in my four pairs (all from later runs with the 16/8 uf combination).

I have been thinking of at least removing them and measuring but the speakers sound good.

I have refoamed all of them using the real floppy surrounds which is the type to use with AS systems.

Doug

Film types could make a significant difference if your old NPE's ESR had crept up significantly. Installing the very low ESR film types would give you more noticeable treble. If that's a huge concern, stick with new NPE's or, get film types and add a low value (1/3 to 1/2 ohm) resistor in series as Pete Basel has suggest somewhere here.

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