17 replies to this topic

[DON]

Gotta keep things moving here so I have at least two questions.
Are the woofers (big speaker) for the smaller Advent the same as the ones in the Large Advents?

Are the woofers with the masonite trim the same as the steel frame woofer without the masonite?

The foam surrounds from Simply Speakers seem heavier/stiffer than the ones Looney Tunes sells on E-bay, the outer rim that attaches to the metal ring is much wider and the roll is smaller. Which do you prefer? I think the ones from Looneytunes make it easier to center the cone.

Y'all enjoy the rest of your fourth!


I'm thinking of stacking two pairs of my Advents and biamping them with a pair of Adcom 555II amps. Good idea? Bad idea? The hardest part for me will be stacking. Why use 2 amps..........because they're there. I'm also thinking about bridging the amps and hooking them up to my 801s.

[JKent]

you'll get the correct surrounds from M_Sound. Great service
Kent

[DON]

you'll get the correct surrounds from Z_Sound. Great service
Kent

Thanks Kent. I tried to locate Z_Sound but I couldn't. Can you point me in the right direction?
Any comment on the woofers? I'm fairly sure the woofers from the smaller Advent is the same as the large Advent but I know very little about the woofer with the masonite.
You're always very helpful and I appreciate you.

[JKent]

Thanks Kent. I tried to locate Z_Sound but I couldn't. Can you point me in the right direction?
Any comment on the woofers? I'm fairly sure the woofers from the smaller Advent is the same as the large Advent but I know very little about the woofer with the masonite.
You're always very helpful and I appreciate you.

OOPS typo! I meant M_Sound. Sorry
http://www.citlink.net/~msound/

[Doug G.]

Hi Don,

In the original versions of Advents, the Smaller Advent woofer is NOT the same as the full sized Advent Loudspeaker which is the one with a fairly wide masonite ring on it. The Smaller Advent woofer is a bit smaller and has a kind of cardboard ring and the surround goes on top of that ring as opposed to the full sized Advent surround which goes under the masonite ring. The Smaller Advent woofer also has that big "spitwad" dust cap on it.

When they brought out the replacement New Advent (for the full sized Advent) and Advent/1 (for the Smaller Advent), they used the same woofer for both which was the all-metal version. Same drivers - the Advent/1 just has a smaller cabinet, of course.

The surround for the all-metal version of the woofer will work for both the masonite and all-metal. The only original difference was the original Advent surround had a wider flange at the outside edge to glue onto the back of the masonite and the all metal one had a smaller flange here to fit onto the ledge on the front of the driver. The narrower flange works fine to glue to the masonite.

You do want to get the more compliant surrounds with the larger (17 - 18mm) roll as from Rick Cobb (LooneyTunes). That is what Advent used. When installed and the woofer is out of the cabinet, it should take very little force to move the cone. You can feel the resistance with those crummy thick and stiff ones.

When stacking, if at all possible, use a separate stereo amp for each pair. Although most solid state amps will handle the load of two in parallel, a solid state amplifier has better control over the woofer cone with an 8 ohm load and lower frequencies will sound better - less "flabby".

I'm sure Kent understands we are just teasing him with the woofer (big speaker) deal. \:^)

Doug

[DON]

Hi Don,

In the original versions of Advents, the Smaller Advent woofer is NOT the same as the full sized Advent Loudspeaker which is the one with a fairly wide masonite ring on it. The Smaller Advent woofer is a bit smaller and has a kind of cardboard ring and the surround goes on top of that ring as opposed to the full sized Advent surround which goes under the masonite ring. The Smaller Advent woofer also has that big "spitwad" dust cap on it.

When they brought out the replacement New Advent (for the full sized Advent) and Advent/1 (for the Smaller Advent), they used the same woofer for both which was the all-metal version. Same drivers - the Advent/1 just has a smaller cabinet, of course.

The surround for the all-metal version of the woofer will work for both the masonite and all-metal. The only original difference was the original Advent surround had a wider flange at the outside edge to glue onto the back of the masonite and the all metal one had a smaller flange here to fit onto the ledge on the front of the driver. The narrower flange works fine to glue to the masonite.

You do want to get the more compliant surrounds with the larger (17 - 18mm) roll as from Rick Cobb (LooneyTunes). That is what Advent used. When installed and the woofer is out of the cabinet, it should take very little force to move the cone. You can feel the resistance with those crummy thick and stiff ones.

When stacking, if at all possible, use a separate stereo amp for each pair. Although most solid state amps will handle the load of two in parallel, a solid state amplifier has better control over the woofer cone with an 8 ohm load and lower frequencies will sound better - less "flabby".

I'm sure Kent understands we are just teasing him with the woofer (big speaker) deal. \:^)

Doug

Thanks Doug. The surrounds I'm using are from Rick. They make it easier to center the cone......for me at least. They have the large roll and feel more compliant than others I've tried. I have three pair of Advent amps and when I figure out how I'm going to use one pair to power the stacked Advents.
As soon as I receive the parts I'll finish my AR2ax project.




Rick.........I'm only kidding you a bit with the big speaker comments. The fact is a lot of us would benefit from explanations that make terms easily understandable. We also appreciate that you are usually the first to answer our sometimes "dumb" questions.

[T1mbo]

Hi, i'm new to refoaming speakers. I have a pair of Advent 4002's. Recently I finished refoaming a pair of Infinity RS-10 bookshelf speakers with the kit from SimplySpeakers but I've heard that their foam is too thin to hold larger woofers and tend to droop. Maybe you could dispel the rumors and hearsay for me.Would Rick Cobb's (Looneytunes) be the best choice for new foam surrounds for my particular speaker?
Another thing, I came up with the idea (at least I think I came up with it first) of hooking a AA battery to the leads of the speaker to make it move up or down while I'm putting the foam in place, the idea being that I'm using the speakers own magnetic field to keep the woofer centered. I did this with the Infinity's I mentioned earlier and it seemed to work fine. Would it work for the Advents?

[JKent]

see post #2 and #4. I just bought more surrounds from M_Sound to do 2 pair of OLAs with metal (no masonite) frames.
Kent
PS Yes. I do know people are goofing on me for the "big speaker" comment. I always appreciate a laugh. To tell the truth I forget how that got started. I think someone indicated in a question that he knew nothing about speakers, so I clarified a comment about woofers by calling them the big speakers. Hope the person I was answering did not take offense.
That's a problem with written communication like this. You miss the tone, nuance and body language.
Anyway. "Big speaker" IS kinda funny

Edited by JKent, 29 February 2012 - 11:38 PM.

[T1mbo]

I'm seeing a split of opinions on the best foam suppliers. Why do you say M_Sound's foam is better Kent?

[ironlake]

The masonite woofers have a square magnet and the latter all steel frame woofers have a round magnet. To me it seems the round magnet wouid give the same magnetic field to the voice coll all the way around while the square magnet is always a different distance from the voice coil all the way around.
The square magnetic appears to and weighs more than the round one so maybe the difference in the field of the square magnet will compensate for the difference.
Personally I always felt the masonite speakers had more real deep frequency response to them. I had two pairs of advents one original all wood with masonite woofers and fiberglass stuffing and the others were stuffed with yellow foam that had the all steel frame.

The reason I felt the lower hz on the masonite woofers is they had fiberglass stuffing vs yellow foam on most of the all metal frame woofers and the fiberglass gave a slightly lower Q for a lower hz. Also as the yellow foam rots the stuffing gets less dense and the stuffing will give less resistance to cone movement rasing the Q.
Please correct me if wrong,.

[JKent]

I'm seeing a split of opinions on the best foam suppliers. Why do you say M_Sound's foam is better Kent?

First--ALL legitimate suppliers of foam surrounds are buying from the same manufacturer, so there is no difference there (actually, some super-cheap epay sellers are selling seconds from Mexico and China, but the sellers of 1st quality stuff get them from the same factory). M_Sound goes to great pains to make sure you get the correct surrounds or the best surrounds for your speakers. For example, some suppliers sell the same surrounds for the masonite woofers and the steel woofers. They are NOT the same. M_Sound was the first to adopt recommendations from knowledgeable CSP members regarding "filled fillet" surrounds for certain speakers. His kits are VERY complete. Don't need the full kit? He'll give a little discount. CSP member? Discount (these are not big profit items so the discount will be modest. Contact him through his website to avoid ebay fees). M_Sounds glue (pardon me--his white dampener) is superior to the glue used by many other suppliers and as Roy pointed out, MUCH easier to work with. It is water-based so you can smear it with your finger if you want and any goofs will clean off with water. The owner, John is very responsive to questions. He offers excellent support. He also offers many different dust caps in various diameters and materials, depending on what your needs are. There is no "one size fits all" when you get an M_Sound kit.

First-timer? You REALLY want an M_Sound kit. John supplies EVERYTHING and his instructions walk you through step-by-step. I was very intimidated when I did my 1st pair but I followed his instructions to the letter and they came out beautiful. OTOH, I recently bought some AR91s that had been refoamed. Looked like a chimp did the job. Thick solvent-based adhesive all over the place. See post #12 in this thread: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=6565&hl=ar91&fromsearch=1 M_Sound's adhesive is very forgiving. The stuff from Simply Speakers and some others is not. I had to send them to Millersound to be redone correctly (btw, I don't know why I did not think of it at the time, but M_Sound will also do the refoaming, reconing or other speaker work for you. I'm a BIG fan of Bill LeGall's work but would not hesitate to send speakers to M_Sound for any work that is beyond my level of expertise).

I may think of more reasons but I'm totally sold on M_Sound.

YMMV

Kent

Edited by JKent, 02 March 2012 - 04:57 AM.

[tnt1451]

@ironlake: Just so you know, I have an original Advent Woofer from the NLA's(metal frame) and they have a square magnet, as does the factory replacement from the mid to early nineties.

[Pete B]

The round magnet LA woofers are made by Jensen, the square magnet by Advent.
All the square magnet woofers have roughly a 3/8" thick top plate with a flat back
plate. The round magnet version has a 1/4" top plate, a raised back plate, and a
paper rather than fabric dust cap.

The Jensen woofer might have more linear throw, but I'd have to open one up
to be sure. I'm interested in a blown round magnet driver if anyone has one to
offer.

[ironlake]

Yeh, I found out that the entire woofers on my utilitys had been replaced with evidently jensens. I still feel the round magnets promote a more liner excursion of the cone with equal field strength all 360 degrees of the magnet.

[tnt1451]

Thanks for the clarification Pete.

Side question: What do you mean by "linear excursion"? Is it having to do with the amount that the woofers excurse, or how it excurses?

[Pete B]

Thanks for the clarification Pete.

Side question: What do you mean by "linear excursion"? Is it having to do with the amount that the woofers excurse, or how it excurses?

When we refer to Xmax it is usually the theoretically linear excursion as defined by an equation that assumes a perfectly square magnetic field in the gap. There is a large fringe field in reality but the theoretical number gives us something to work with. This is the traditional definition that has been used for at least 30 years or so. Some use double the actual just to lie for marketing reasons. Many today use a number where the motor strength is 70% of the maximum, this gives a bigger number to be more impressive.
Here is a defintion with a picture, it is essentialy how far the woofer can move while an equal number of turns are kept in the magnetic field. It is also called overhang when the voice coil is longer than the magnetic gap:
http://www.subwoofer...er.com/xmax.htm

No one I know in the field believes that there is any difference between a round and square magnet, I certainly do not believe there is.

[ironlake]

There is definately more amount of magnet material with the square magnet LxW, vs the round one pie D. So did jenson get by using less magnet materai do to the even field strength of the round magnet and save some money on the speaker cost.
If there is no difference in the two magnets why did the bother to change magnets in the 1st place.

[Doug G.]

I don't think it was really a matter of changing them. Advent just used square magnets and Jensen used round ones so when Jensen took over building Advent speakers and building their versions of the drivers, they just used their already available round magnets.

Doug