Guest gkentsmith

All Advent questions answered

108 posts in this topic

Hi to all :-) ,

I am new to this web site and to this forum. I am a self-described expert in all things Advent. Please, if you have any questions, use this post to ask your questions. If I don't know I will tell you. Chances are I DO know since I have been a close follower of the founder of Advent, Henry E. Kloss, for many years. I also have a ten cubic foot inventory of almost any model built by Advent or by the post-bankruptcy owner (Jensen - a.k.a. Advent-Jensen).

I also buy and sell vintage Large Advent loudspeakers, Smaller Advent loudspeakers and many other models, especially the early years from 1969 thru mid 1975. I will be happy to discuss sales or purchase of any model Advent made from 1969 through (approximately) 1992. Anyone looking to sell a Powered Advent pair in working condition would be of great interest to me.

Thanks for reading this and please feel free to contact me directly if you prefer. If my email address is not available on the forum, let me know you are interested and I'll send you my email address. As soon as I find out if it's permitted, I will post it in a separate message.

Have a great time,

Kent

:D

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Hi Kent. Welcome. I see you buying and selling all the time on you-know-where :^)

OK, if you're such a fancy schmancy expert, what is the definitive difference between the orange and green fried eggs (besides the color)?

Please take this the right way. If you really were to know, you really would be THE expert.

Doug

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Welcome aboard!

I have a pair of large walnut Advents, 2 pair of AR3a's, one pair of AR3s on the way, EPI 100s and a pair of AR7's.

The Advent tweeter always seemed a little harsh to me.

What is the best drop in replacement tweeter (that's easily available) for the Large Advent?

Or. Would upgrading the 30 year old caps & resistor in the crossover bring that tweeter under control?

Once again, a warm welcome.

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Wow, I can see I've set myself up (lol). Are you referring to the early green tweeters or the later ones which were used in a few of the Large Advents? :D

Ok, that was a cop-out answer, but it was also intended to be in the spirit of fun in which you asked your question. Here is the straight skinny based on my own testing.

As far as DCR is concerned, there is NO DIFFERENCE electronically between the two tweeters; they consistently read around 2.9 ohms (+ or - .1). This applies to the most common of the tweeter styles, the ones with the 45 degree canted masonite board and the wire mesh grill covering the tweeter.

The earlier version (the wire mesh covered tweeter on a masonite board that is canted only a few degrees) also seem to test out identically, but I've only had a very small number to test. On both the orange and green of these, they were mounted to the speaker using putty as a sealant as opposed to the later foam gasket.

Sadly, I have never seen a pair of the Smaller Advent with an equivalent tweeter to the original 1969 Large Advent who's tweeter had no wire mesh over it.

I hope I've passed your test (lol). Keep them coming - I enjoy the challenge.

Kent

:D

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Hi and thanks for the warm welcome. In my humble opinion the best solution would be to upgrade the caps and resistors in the crossover network. The Large Advent was designed to take advantage of the slightly forward mount provided by the design of the tweeter. This feature eliminates some problems with frequency distortion that you can have with a flush mount tweeter and woofer.

If you decide to change out the tweeter anyway after trying the uprades you suggested :-( , there is one option you should implement at the same time. As was done on the AR9 and the Rogers LS3/5A, isolate the tweeter from the possible interference of the woofer by placing a 1/2 inch thick by 1 inch wide strip of felt around the tweeter at about the position of the current mounting plate.

I assume you have tried the different toggle switch settings on the back. Beyond the above I can only suggest that you try to find a tweeter which will match up well with the opening, is a nominal 3 ohms, and is designed to handle everything above 1.5khz. Your best place to look would be on the J&R audio web site. They seem to have everything you could ever imagine. Sorry I can't recommend one in particular.

Good luck and keep me posted,

Kent

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>Wow, I can see I've set myself up (lol). Are you referring to

>the early green tweeters or the later ones which were used in

>a few of the Large Advents? :D

This is actually relevant because when I bought my pair of walnuts made in 1975, I originally thought that the tweeters must have been replaced at sometime because they are green. I have since decided that they are original since the tweeter dates (AUG 29 1975)and the scrawled dates on the speaker boards (8-26 and 8-27) agree. I have also seen pictures of others built in 1975 with the green tweeters. They have the bigger magnets of the Large Advents also. DCR the same as the orangies. By the way, these were built a little less than a month before my daughter was born.

What was Advent doing in 1975?

>Ok, that was a cop-out answer, but it was also intended to be

>in the spirit of fun in which you asked your question. Here is

>the straight skinny based on my own testing.

>

>As far as DCR is concerned, there is NO DIFFERENCE

>electronically between the two tweeters; they consistently

>read around 2.9 ohms (+ or - .1). This applies to the most

>common of the tweeter styles, the ones with the 45 degree

>canted masonite board and the wire mesh grill covering the

>tweeter.

Agree!

>The earlier version (the wire mesh covered tweeter on a

>masonite board that is canted only a few degrees) also seem to

>test out identically, but I've only had a very small number to

>test. On both the orange and green of these, they were mounted

>to the speaker using putty as a sealant as opposed to the

>later foam gasket.

Yup, I have decided that the ones only canted a few degrees are earlier. It appears that Advent only turned the masonite enough to enable access to the mounting screws and then later decided to standardize the 90 degree turn. I have heard before that the earliest ones used putty on the tweeters too but I have never seen any like that. I believe it though.

>Sadly, I have never seen a pair of the Smaller Advent with an

>equivalent tweeter to the original 1969 Large Advent who's

>tweeter had no wire mesh over it.

I think that's because the Smaller Advent wasn't released until they started applying the grilles to the tweeters. They began putting the grilles on in 1971 and actually supplied grilles to owners of earlier speakers free of charge if they wished to add them.

>I hope I've passed your test (lol). Keep them coming - I enjoy

>the challenge.

Hehe, kind of but we still don't know why some are green and most are orange :^) Maybe they ran out of orange light bulb paint for a while :^)

>Kent

>:D

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Hi There;

Welcome Kent to CSP.

Actually the green Advent raised tweeters were only produced on St Patricks Day.

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Hello, gks.

I have a pair of 5012W's, made during the Jensen years. To me, they sound exactly like the Advent Loudspeaker, though the x-overs are different and the cabinets are slightly larger in every dimension—about 1/2 inch.

They never seem to draw much interest on eBay, and rarely come up there. So I have this very nice pair, in very nice condition, with new poly caps and pretty fresh woofer surrounds, and I'm wondering what to do with them (since I already have 4 Advents in a double system and two very lovely Smaller Advents I recovered in white birch veneer and refurbished with new tweeters and x-over components—AND resting securely on beautiful stands I made myself).

If you have the answer to THAT, you most certainly ARE and expert, because anyone who knows what action I should take has to be an expert. I am expert at many things, but knowing what to do is not usually one of them ;-).

Your original post was engaging.

Best wishes.

Russ Wollman

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>Hi There;

>

>Welcome Kent to CSP.

>

>Actually the green Advent raised tweeters were only produced

>on St Patricks Day.

Oh Great! Another Advent version. "The Irish Advent Loudspeaker"! Hehe.

No wonder "Danny Boy" sounds so good on my greenies. :^)

Doug

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Hi Russ,

Thanks for the welcome. Well, you've got me stymied. If I had room (or the money) for another pair I might make an offer on the 5012s. Right now I'm just trying to make room for more Smaller Advents to continue on my version of what you've already done.

Funny coincidence. My prototype pair of "customized" Smallers will be veneered in Birch also (only because it was one of the least expensive veneers to learn on). I'd be interested in knowing more about the other things you did to the Smallers. If you like, email me and we can go into more detail off the thread and not bore everyone (lol).

Thanks again for the welcome,

Kent

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OK, Kent, we might as well get this out of the way.

Rule #1:

There is no boring re:Advents.

OK? OK. :^)

Doug

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Ok Doug,

I agree, but really, you want to know details about stains and veneering techniques? Well, then, more to come. Holler when it's too much (lol).

Kent

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"If you decide to change out the tweeter anyway after trying the uprades you suggested , there is one option you should implement at the same time. As was done on the AR9 and the Rogers LS3/5A, isolate the tweeter from the possible interference of the woofer by placing a 1/2 inch thick by 1 inch wide strip of felt around the tweeter at about the position of the current mounting plate."

Now wait a minute....you lost me here. Are you talking about the felt *under* the mounting plate to protrude the newer, flatter tweeter styles??

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I used birch for the same reason and because I like light woods.

I glued the veneer directly over the vinyl after roughing the existing surface a bit. And I used Weldwood Gel Formula contact cement rather than the original more messy type.

What else did I do to them? Besides new woofer surrounds, I think I just replaced the caps and left the rest; though I did install banana jacks for easy connection. I did replace the grille cloth with something like the original, a light gauze fabric backed with black silk-stocking like material. They look very nice and the stands came out very well.

I'll try to make some photos and post.

Though I don't use them much, I'm reluctant to put them up for sale, especially on eBay, where things like this—very nice but homemade—cannot be properly evaluated and appreciated.

So I will keep them if only because they look so nice.

If you want to know more about veneering, you can mail me. I got good results—not perfect, but very good—with a sharp blade in a utility knife and careful work. I have no fancy tools, preferring to avoid investments in expensive gadgets for infrequent use.

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Russ,

You have added some to my knowledge already, thanks. I'm actually stripping the vinyl before veneering. It's easily done with a hair dryer and heat-resistant fingers (lol). My biggest concern is if the edges would look funny after staining. I'd like to see your pictures when they're available.

I made a cool find when stripping the vinyl off one of the speakers. I can now say with absolute certainty that the MDF used by Advent was "Premium Grade Interior Floor Underlayment" (I found a manufacturers stamp on the wood of one speaker). A typical Henry Kloss kind of approach.

I may offer a prototype pair on eBay just to get the awareness up. Besides a custom pair for myself, I'd like to approach the decorators around the Lake Tahoe area. I intend to offer a "customizeable" Smaller Advent at a price they deserve ($650 - $1000 as per Stereophile 05/2006). Selling price will be based on veneer, finsh, and grill cloth chosen, not eBay prices.

My plans also include upgrading the crossover caps without changing their values and changing the connectors much as you did. There are a lot more minor changes I plan to do that will not change the sound or the appearance (other than as mentioned above), but right now I'd love it if you or someone could advise me about stains and finishes. I know there are people on this forum who have dealt with the stain and refinishing of veneered speakers and would love to get any tips they might want to pass on.

Looking forward to some pics,

Kent

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Guffaw. Heat resistant fingers. That really did make me lol.

As part of my previous job, I was always making test fixturing for very small circuit boards (for hearing aids). I used a lot of Plexiglass which had protective paper on each side of a sheet.

When the sheets were new, the paper was easily removed. However, when the stuff got a little older, it kind of stuck to the Plexi.

I used a heat gun and my fingers to remove it. Sure could have used Kent's "heat resistant" fingers then. :^)

Never could understand why things get so hot when you heat them up. :^) Like, when a solder blob drops onto your skin; why is it so dang hot? :^)

Oh, Advent content - I like Advents too. :^)

Doug

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Doug,

I think all hot things should affect your skin like the candle wax your "special friend" uses on you. Oops - I really do love Advents, too.

Say, did you know that the Advent/2 also came in a hard Plastic cabinet that looks like the Advent/400 speaker on MASSIVE doses of steroids? Getting to the woofer requires GENTLY prying the backplate out because the drivers are mounted from the rear, and the stamped metal "mesh" grill was designed not to be removed (not true once you take out the woofer, he..he..he). Seems like Advent was even more schizophrenic than we realized - lol.

Does anyone know where I might find surrounds for that odd sized cross between the Large Advent and the Smaller (foam goes on like the masonite 10", but the ring is made of dark grey cardboard like the Smaller)? The cone diameter is 6-3/8 inches, and the hole diameter is 7-1/2 inches. So far, I'm looking at having to cut down Smaller Advent surrounds to do the job and I HATE that approach! Any tips would be appreciated.

Thanks,

Kent

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Kent, I used no stain on the birch. The edges, though, are darker probably because my trimming method was relatively crude, employing just a utility knife and my hands, which are supposedly linked with my brain. I finished the birch with ZAR satin polyurethane, which gave a nice, smooth, subtle sheen.

Here's a nice overview on finishing wood: http://www.taunton.com/finewoodworking/pages/w00060.asp

And I wrote this from my own experience:

Another choice, one I've used, is WATCO danish oil finish, which is available in various wood colors or natural. I used medium walnut. It's not a surface coating like varnishes or polyurethanes, and imparts a subtle sheen to the wood. WATCO also offers a finishing wax, which can be applied with #400 or #600 sandpaper after the oil has dried, to provide additional sheen and a very smooth surface.

These oil finishes do not provide the surface protection from liquids which oil-based coatings do provide. But the look is smoother to the hand and to the eye. If you decide later on that you want to coat an oil-finished surface, it's no big deal. All you have to do is remove the wax—if wax was applied—and sand the surface a bit. But if you apply a surface coating and you don't like it, you have to remove it chemically or sand heavily again.

There is one oil-base polyurethane which I like much better than Minwax or Olympic, the typical mass market stuff. ZAR is the brand, and their satin variety gives very nice results, especially when used with a foam brush rather than a bristle brush. ZAR levels nicely and dries quickly.

Water-based finishes are all right, never as smooth or durable as oil-based polyurethanes, but the odor is low and clean-up is easy.

Another choice is a urethane product from Cabot, called Cabothane. It's several times more expensive than anything else and is primarily for exterior architectural applications. I have not used it on wood but have coated exterior brass with it using a foam brush. It gives a high gloss and is pretty tough stuff. It's white in the can and dries clear. It is NOT polyurethane, but urethane. When it's dry it's like a sheet of clear plastic.

I have heard of some finishers using lacquer but I have no experience with it at all. Lacquer, I think, can be smoothed between coats, and in skilled hands, it probably yields the best results.

Before applying any finish, sand the surface with fine paper such as #400, proceeding with the grain of the wood. Then remove all the dust with a tack cloth or a cloth moistened with turpentine.

Remember that the veneer is thin, and if you're not careful, you can sand through it if you use too coarse a grade of sandpaper, like #150. Stick with #400 or #600 especially if the surface does not require heavy sanding to remove scars and marks.

There's a plethora of advice on this subject and all kinds of opinions. If you have time and are short on experience, experiment a bit with foam vs bristle brushes and the various products available—or ask someone who works at a good lumber yard and has done the work. There are still a few people out there who have the experience and knowledge.

And this came from another CSP member, John O'Hanlon:

The...website of another well-known woodworker Sal Marino:

http://members.aol.com/woodinfo1/salpage.htm

See the second link in the listing "supersmooth finish"

Here he describes how to use Watco Walnut Danish Oil stain with 320-grit (not finer) wet-or-dry paper on walnut to achieve a really smooth finish with the same satin sheen. He gives step-by-step directions at the end; what is important is the use of 320 grit paper to generate sawdust that, when mixed with the oil stain, fills the pores of walnut (or oak). Good reading.

John O'Hanlon

This should be enough to get you started—or at least confused.

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Hi russ;

Thank you very much for your write-up.

We can never have enough good advice.

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Thanks Russ,

I bought a couple of finishing books at Woodcraft, the same place I bought my veneer. I think they are having a veneering class next month and if it's not too expensive I'll probably go.

Your sage advice helps me to understand better what the hell those craft books are saying and you may have saved me a lot of trial and error. Needless to say, both the veneering and the staining/finishing will be tried out on scrap wood. You're comments about the edges being darker touched on one of my concerns. I think I can eliminate all forward facing edges by proper design, but there is no way to avoid the problem at the top where it meets the sides. A woodworking friend already advised that it would be impossible to cut the veneer edges at a 45 degree angle due to the thinness of the veneer. Thankfully I bought a 61 piece x-acto knife set months ago to do the kind of cutting needed.

Wish me luck, and please send pics when you can.

Thanks,

Kent

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I've worked with Dynacos, Advents, ARs and KLHs and find I CAN get away with 150 under an art gum eraser for the coarsest sand, so long as I use a light hand and don't over-do it. Removing the light coat of polyurethane (or whatever it was) that most manufacturers used in the early 1970s is no problem with this method. I finish with 320 or 600, followd by 0000 steel wool, depending on how smooth I want to go...

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Oh how I hate to eat crow! Guess what? At one time there WAS a definitive difference between the green and the orange tweeters. I am currently organizing my spare parts and other things related to the work space.

I found a pair of green tweeters with a SMALLER MAGNET than the magnet on the orange tweeter and some of my green tweeters! This is completely consistent with the page Advent9.jpg of the brochure in our library under the subject: Brochure describing the The Advent, Smaller Advent, and Double Advent loudspeaker systems.(http://www.classicspeakerpages.net/advent/advent_broc.zip)

The really odd thing is that I have at least 5 or 6 of these and never noticed the short reference. The good (?) news is that I still get a DCR of around 3 ohms on both the smaller magnet green and the larger magnet orange.

Now, in addition to everything else, I have to hook up both sizes of green tweeters to crossovers and see if there is any difference in impedence. The things a guy has to do to retain the "self-described expert" status is getting complicated (lol).

Anyone have an idea if the smaller magnet will affect performance regardless if the impedence is the same?

Kent

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I thought that the green tweeter was used in the Smaller Advent speaker, with a 4 ohm impedance. The literature that I have talks about being able to use a smaller magnet on that tweeter (lower sensitivity and lower cost) because of the sensitivity difference between large and small woofer. Making the Smaller a 4 ohm impedance allowed solid state amps and receivers, which were plentiful by this time and likely to be used with a speaker in this price range, to deliver more power to the speaker.

Bob

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As the document in our library states it you are correct. The THREE tweeters (orange, small magnet green, and large magnet green) all yield precisely the same reading on 2 separate multimeters. To confuse things further, I have 5 of the sales brochure like the one in the library. Four of them make a point of the smaller magnet. One states that they are identical. Each brochure has a slightly different format than the other. I will test all three tweeters hooked up to the crossovers I have and see what I can find. I will post the results here in a few days.

As far as the 4 ohm question is concerned, that is a total system function. It includes the woofer and the crossover. I would like to know, if the ohms are the same (they are), does the magnet size affect audible performance.

Curse you Doug, for starting this!

Peace,

Kent

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