Can't find this (at least not definitively) when Googling:

Anyone know how a speaker cone is measured when looking for a replacement? Yes, I'm open to any help from someone who works for (or owns) a speaker manufacturing company and is likely to know the answer fer sher!

Is it the White line measurement (the cone itself)? or...

The Magenta line measurement (including the surround)? or...

The Green Line Measurement (outer mounting ring)?

I have some old Design Acoustics speakers (Audio-Technica) that are no longer made but would be great for my workshop if I replaced the woofers....


TIA!!!

I am not a "fer sher" kind of guy, but I would bet dollars to donuts that any after market drivers will have specs for the drill holes to use as a guideline. If I were buying a replacement cone, I'd look for that spec within a particular cone size and wouldn't rely on the cone size spec as definitive (for the reasons you suggest above).

Now, for someone who's not guessing to chime in...

AFAIK, it's the purple line.

I remember the Design Acoustic speakers rather fondly. I had the PS30 system years ago, I really liked them and wish i would have kept them.

I think Ken is right.

I thought you were just supposed to replace the foam surround part thingy. Not that I've ever actually gone that route myself.

I think that's something you can do, but I haven't a clue how. I know my parents have paid a fair amount of money to have it done on their speakers.

Its a relatively simple procedure, You basically just remove the old surround and glue the new one on. Although you may or may not have to cut off the dust cap and shim the voice coil in the gap otherwise it can become off center and rub. The last time I put new surrounds on a pair of drivers I did not have to do that. Parts express sells refoam kits. They can also help you select a new driver that would work well in your speakers if you did not want to refoam them.

Ken, it's clearly magenta.

Thanks for the suggestions!

I hadn't considered replacing just the foam....but my next round of questions would have been along the lines of "Now how do you pick a replacement driver that won't be 3dB less efficient (and therefore "quieter") than the original", etc... I guess if I just replace the foam, I don't have to worry about driver specs!

The Design Acoustics "Point Source" series sounded pretty good. They were relatively deep cabinets with a comparitively small front baffle with the idea of providing needed internal volume with a "near" placement of woofer to tweeter so as to be closer to a "point source" design. I'm impressed with the internals now that I took a driver out.

I'm looking for something for my workshop and I was thinking....don't laugh.... about these simply because the two overriding factors are "inexpensive" and "louder than a woodshop".

OK, ok. I asked you not to laugh!

How much louder could a woodshop be if a woodshop could shop wood ?

Joyce says "CHOP wood" would be funnier!

But excellent retort!

Sorry, I assumed you did more than just chopping in your shop, but perhaps it does consist of just an axe and a hungry woodchuck.

You artists can be funny like that...

LOL!

By the way, who's Joyce to decide what's funny? I laugh at her attempt to be funny!

Nice to be on the other end of that exchange for once, eh?

P.S.

Magenta?!?! The line is clearly Maginot!

Mark, first I laughed. Then, I thought, that's a pretty big cabinet for the price. Then, I thought, you could replace the woofer - or all the drivers - if it really sounded bad. Or maybe even put a new, more powerful amp in it. Or just engineer your own powered monitor from the ground up! That's the ticket!

Or maybe some wireless over-the-ear headphones. Hearing protection and tunes all in one.

I just love Mark's little projects.

Refoam em! And take pictures!

I can't seem to find the link right now, but most drivers are measured according to the basket size and it has very little to do with the actual cone size, otherwise Axiom's 5.25 would a about a 3" driver.

Ah, so a Basket Case, then?

Zzzzzzzz...

Huh? Wuzzat? Did I hear the Bat-siren?

Mark, as Jason points out, cone speaker drivers are measured by the outside diameter, i.e., your green line. The Axiom 5.25" mid-woofer measures 5 1/4" across.

Wait, wait, wait. Are you telling me Mark could have taken a driver with a diameter of know size spec, and measured it himself to see what that spec corresponded to?

No! That would be wrong!

And besides, what if a properly calibrated ruler wasn't available?

Smarta**es.

You know that Axiom gets love from me, and I'm NOT saying that I don't trust them. But, there are lots of speakers out there that claim an 8" woofer, while the reviewer notes it's 7" or something similar.

There seems to be lots of confusion on the subject, as Googling for it brings up many different answers. I just want to know what the "official" measurement is in the industry.

Exactly. Because the metal frame adds .5" all the way around.

Which is obviously better than dumba**es, but not quite as evolved as wisea**es.

Through a typical day, I am all three.

Holy Trinity, Batman!

UN-holy, actually.

Stop Robin my thunder.

Oh, Jeeeeez, here we go......

Everyone hold on!

I was hoping that Alan will drop by sometime and contribute his knowledge to this thread and answer Mark's original question. I am not as hopeful anymore but certainly enjoying the wise cracks. Perhaps Alan is as well.

I am surprised that a standard similar to measuring tires does not exist for speaker drivers.

John

Warning:
I tried to help out by measuring my wifes cones.

let's just say that didn't work out very well for me.

Hi Mark,

Generally when driver sizes are specified, you use the purple line, so the diameter includes the foam surround, as KCarlile and others have already noted.

Sometimes I've noticed that manufacturers interpret driver dimensions rather broadly and include the widest possible dimension to the outer edges of the basket.

While it may be fun to buy kits to add new surrounds to drivers whose foam surrounds have deteriorated, don't expect the speakers to perform anywhere close to their previous standards. The elasticity/damping of a driver surround is carefully specified during its design and re-foaming can never hope to duplicate those standards.

It's certainly OK to get an old pair of speakers working again, but in my view, nostalgic memories of cherished old speakers should remain that way. Besides, I've found that when you drag a pair of those much beloved old speakers out of the closet (I have a fair number of them) and put them into a controlled double-blind A/B comparison with really excellent modern speakers like Axioms, many of the old speakers sound truly awfu and very colored. It's astonishing the progress in speaker design and fidelity that have taken place since the 1960s and '70s.

Regards,

Alan

My brother restored jukeboxes and found that there's a thriving business there re-coning old jukebox speakers (and refurbing their amps).


Alan -- any thoughts on how long foam surrounds are good for? Ballpark 10 years? 15?

Hi Anthony11,

Re-coning old speakers for jukeboxes and the like is fine.

The type of foam surround that a lot of manufacturers back in the 1980s, including Axiom, began to use seemed to last about 10 or 15 years, but it also was influenced by the climate and humidity. A competitor of Axioms who shall remain nameless introduced a very large subwoofer that used a 15-inch driver and discovered that purchasers of the product who lived in the Caribbean found that the foam surrounds disintegrated after a year or so of use.

Nowadays, virtually all quality manufacturers use a rubber composite or butyl type rubber that should last many decades.

Regards,
Alan

Yep, it was kind of scary seeing how non-precision those things were, and of course they're not anywhere near linear.

Now, if I could only find someone who could fix my SMC-1

Glad to hear that modern surrounds have an increased lifetime -- that may help with the ever-popular WAF in justifying my Axiom purchase.

I'll certainly agree with that statement. My first speakers were a pair of Advents, considered one of the best value priced speakers of the time. In todays $ they fall between the M22 and the M60, probably closer to the 60. I am willing to bet that the M22 far outperforms those old Advents.

Wonderfully illuminating as usual, Alan. Thank you very much for sharing your thoughts.

john

Hi,

Thanks, but I think I've been getting too much sun lolling about up here at Axiom.

I just took a ruler to the Axiom M80s, and the 6.5-inch woofers measure exactly that to the outer edge of the metal basket. So do the 5.25-inch midrange drivers. So ignore my comments about woofer diameter extending to the edge of the surround material.

Regards,

Alan

Heh heh heh heh... guess the question was more difficult than I thought, Mark!

I miss Jack and his supply of raspberry icons.

Thanks for the response Alan!

I'm just looking to put something cheap in my workshop, and these were in use daily in my studio until I heard some woofer farts a month ago and pulled off the grill covers to notice the foam. They weren't, and in a workshop certainly won't ever be, for critical listening.

Of course, this still leaves me unsure of replacement sizing. I wrote to PartsExpress 3 days ago, but no one has written back.

Well, what are the diameters that you see? It's more likely a 10" woofer than an 11", or a 12" instead of an 11". And certainly much more likely a 10" than an 8.5".

It's not that easy.

5".... 5 1/4".... 5 1/2".........

I'm good. I'll wait to hear back from Parts Express or I'll just call them...

You could always buy more than one and return whatever doesn't fit.

I am shocked that they don't have a screw hole spec in there somewhere. That has seemed to me to be the key measurement. Everything else should fall into place after that, right?

I went slummin' and bought a pair of these:


They were on sale at Circuit City for 1/3 off & they are way louder than I could ever stand... therefore meeting both my criteria.

Surprisingly, though, they really are NOT bad sounding at all. As a matter of fact, they sound pretty damn good!

My old D/A's are just gonna go out in the trash tomorrow.....

I hope you washed your hands before going near the keyboard! Goodness knows what you picked up slumming. Why, next thing you know, Ken or J.P. could be at Wallyworld buying an HTIB.

That's it, you're banned.







Oh wait, I can't ban people. Crap.

It's easy. Just close your eyes!

Sean's right - it's easy!

Especially since you're already wearing the ruby slippers.

I was going to make fun of your new "Thunder" speakers by making reference to the old Thundercats cartoon but it would just result in another concerned and confused looking Bert avatar.

Not that I don't like it. I'm just still jealous he found the universal avatar.

Ack. Bert has killed my Avatar!!! Either the web page is just offline or the frustrated looking Bert has finally cracked and blown up Mediafire file hostings.

Sound of the drums
Beatin' in my heart
The thunder of guns
Tore me apart
You've been <boom boom boom> Thunderstruck!

Hey, that's my ringtone!

Oooh, something I can rant about... except I really need to go to work. Perhaps I will rant later.

Yes, and it's really loud, too.

Also, I let the whole song play before I answer.

Urgh, Ken has infected my brain with AC/DC lyrics!

I always liked the video for Thunderstruck. Especially the shots of the bald drummer emoting as he hit the cymbals.

In AC/DC news, look for them at a venue near you: AC/DC TOUR NEWS.

Jedi Kermit is back. Saved by AC/DC lyrics.

The Mal-Wart thing is hard to forgive, tho :-/

Downright impossible, I would think. "Yeah, we're rebels, we'll only sell our music at the biggest corporate store we can find."

Oh gawd, they really did sell their souls for rock n roll.

I hate to say it, but they're just one step away from being billed under a puppet show at an amusement park.

Nah, they're still huge, just flexing muscles and going for as much money as they can. Guess I can't blame them too much. They're just X-treme capitalists.

For those of you that think this thread went OT from my speaker purchase, it hasn't.

"Back in Black" was the disc I used to see how loud these speakers can go.

Seriously!

My first thought was of this compilation I picked up back in the vinyl days.

My second thought was of a "Betty" daily strip from the late 90's or early 00's where they used "Roundabout" to audition speakers.

<--- shows his age.