Advice wanted, crazy idea: Advent mod.

[altair]

Hello everyone,
I have suddenly got this crazy idea to change the drivers in my old Advents, instead of making new complete speakers.
The thing is that I would like to have a better sound than what the original drivers could possibly achieve. And by now, they've given all they had, believe me.
As the enclosures are still in pretty good shape, are of the later model with the nice rounded grille corners, and obviously are already made, this would save me quite a lot of time. As a plus, they are already braced inside with 3/8” dowels from side to side and front to back. (Makes quite a difference to the stiffness of the walls.)

Yes I know, I must be one of the last dinosaurs still listening to these old beasts. In fact, these are not the only ones I got... still have 3 more pairs lying around the house ! They make FANTASTIC computer speakers by the way. I have changed the surrounds on all of them over the years, and one of them is the first pair I originally bought NEW back in … '73 or so. Ha !

Anyway, I would need you guys to suggest some combination of drivers that have a soft sound, as I still want to keep the slightly subdued sound of the originals. I don't like something that is too forward, or too “revealing”.

I took measurements of the boxes:
The internal volume is 1.697 cu. ft.
The woofer opening is 10 inches.
The tweeter opening is 4-¼w x 3-¼h but that could be changed to accommodate any tweeter.
Front panel thickness is 3/4”.

It would probably be best to keep the two-way arrangement because the placement of the original drivers complicates the addition of a third; but I'm open. I also want to keep the boxes sealed, so no ports allowed. I want the nice slow -12dB dropoff that allows to still hear/feel the lowest organ notes.

Your suggestions will be applied to this new build. For years I've wanted to build really good speakers but I still haven't done anything. At least, I hope this mod will stimulate me to go for the real thing later on. I'll take this build as a prelude to the larger design I have in mind.

Thanks in advance

Altair

[altair]

Oh I forgot to mention; of course I will change the crossover to whatever is needed.
Here are some pics.

[Inductor]

Bad idea?
Seas Prestige A26RE4 (H1411) 10" Paper Cone
Seas Prestige A26RE4 (H1411) 10" Paper Cone from Madisound

[Glowbug]

Check out the Econowave thread over on Audiokarma

[DigitalJunkie]

A few years back my dad re-designed the crossovers in his mini Advents,I thought they were pretty good,just a slight bit of tweaking and they would have been the cats pajamas,IMO. I don't know why he just gave up and went back to stock,I thought he was really on to something.

[altair]

Thanks for the replies,
I've checked the A26RE4. Funny thing, it says on the page:
"it had a magical retro sound to it. " He he he, I wonder what must that be...
And I'm not too sure I want to stay with a vintage sound. If I take the trouble to upgrade those boxes, I'll want a 21st century sound.

Actually, the woofers are not too bad, it's the tweeters that have become harsh.

Anyway, I have been looking at Zaph's designs and been wondering how I could integrate one of his small 2-ways into my boxes, while keeping my woofers for additional bass extension. If I have to make a separate compartment for the 2-way, then the remaining internal volume might not be large enough to keep my actual F3 bass freq. Unless I change the woofer to something that can work with the smaller box volume.
That's where I need help.

By the way, I'm still waiting for my account to be activated at Audiokarma to check the Econowave thread.

altair

[skeptic43]

Here's a link to a large advent econowave thread;
My Large Advent Econo-Waveguide Build Thread - AudioKarma.org Home Audio Stereo Discussion Forums
You have a new large advent. I believe the box volume is the same or similar and the same woofer was used in each. In any case this is a proved design with over 70 systems built and over 500,000 views of the econowave thread. Zilch is the guru of the E-wave. You can PM him with questions. He's usually pretty responsive. He resides on the west coast. So allow for any time zone differences.

Another option to consider is Pete Basel's baffle step compensation circuit divulged in a thread in the Advent discussion group at Home Page | The Classic Speaker Pages. You hook it up to your receiver's tape out and amp inputs and it softens the high midrange and low tweeter portion of the response to compensate for a loss of bass if the speaker is normally located away from any walls.

[altair]

WOW ! Thanks for that skeptic.
I'm still waiting for activation of my account at Audiokarma, but meanwhile, I'll have hours of fun at the Classic Speaker Pages.

Cheers

[dcgold2000]

Might not be the tweeters gone harsh but the tweeter crossover capacitor.

Dennis

[altair]

Yes dcgold, these crossovers will be changed. The other thing is that I tend to play my music louder than before, so the defects are more apparent.

Now that I've spent the whole afternoon at Audiokarma, I'm like a child in a candy store.

As a former horn-hater, I suddenly find myself actually considering the econowave mod...

And there is also the baffle step compensation mod at Classic Speaker that I absolutely want to try.

So thanks to all you guys for the leads, I'm having the time of my life... OK, maybe not, but I'm having fun and I'm LEARNING.

Cheers