As relatively decent the existing offerings of cheap coax drivers may be, there's always room for improvement. One can lament all day long about how bad something is (which is sadly very popular these days in our modern social media driven society). I get it to a point, but its wasted energy and it only serves those who get a kick out of finding a common case to gang up on. It appears the social psychology dictates this common behavior and there always must be something or someone to blame.
In the case of the cheap pioneer stuff, they've figured out a recipe for using average quality components which could be pushed to their limit. That limit has long been reached and nothing has changed for decades. We still have the same cheap tweeters mounted on top of the woofer pole piece. No time alignment or optimization for linear FR. Yeah, you can tweak it but not that much. The markup on these car speakers is huge and in most cases the crossover is an afterthought. What serious audio hobbyist wants an electrolytic cap in series with the tweeter and a disgustingly tiny cored inductor in series with the woofer that will saturate at 5 watts?
Then, looking at the other extreme of the spectrum there's these overpriced spit shined monster pro audio drivers which may appear impressive, but they're just like cod pieces for body builders. They all suffer from the same problems.
In between all the chaos you have KEF and Tannoy trying to do something serious with the coav concept. With exception of maybe Eminence, none of the common brands do a decent coax that doesn't need a super computer full of FIR filters to straighten out the response, if it can even be fixed to begin with. I'd sincerely like to see a coax which can be crossed over with passive filters and sound as smooth as a common multi driver speaker. If eminence can get close, then why not get it even closer?
Designing a better coax is definitely possible. The only reason why these cheap compromised designs exist is cost and profit. The consumer used to be the driving force for new product development, but now it appears we are being told what to like. If you don't happen to like it, your made to feel jealous or even left out with the advertising psychology these companies use. Its the same as with Apple IPhones, which are marketed as trendy lifestyle items over the shear functionality and usefulness as a tool. Even my own son has fallen for it. He finally admitted he had to have an IPhone because otherwise he wouldn't fit in at school. If these phones are so great, why don't they have sim card slots or headphone jacks? Anyways, I digress...
If someone had the capability of making an improved coax, why not try? Cone technology is the only area we've seen any advances in speaker technology. Its the weakest link in any speaker. Composites are where its at. While I love the sound of a decent paper cone, there are other substances and combinations thereof which are better. Just look at what Focal and B&W have done with their drivers.
In the case of the cheap pioneer stuff, they've figured out a recipe for using average quality components which could be pushed to their limit. That limit has long been reached and nothing has changed for decades. We still have the same cheap tweeters mounted on top of the woofer pole piece. No time alignment or optimization for linear FR. Yeah, you can tweak it but not that much. The markup on these car speakers is huge and in most cases the crossover is an afterthought. What serious audio hobbyist wants an electrolytic cap in series with the tweeter and a disgustingly tiny cored inductor in series with the woofer that will saturate at 5 watts?
Then, looking at the other extreme of the spectrum there's these overpriced spit shined monster pro audio drivers which may appear impressive, but they're just like cod pieces for body builders. They all suffer from the same problems.
In between all the chaos you have KEF and Tannoy trying to do something serious with the coav concept. With exception of maybe Eminence, none of the common brands do a decent coax that doesn't need a super computer full of FIR filters to straighten out the response, if it can even be fixed to begin with. I'd sincerely like to see a coax which can be crossed over with passive filters and sound as smooth as a common multi driver speaker. If eminence can get close, then why not get it even closer?
Designing a better coax is definitely possible. The only reason why these cheap compromised designs exist is cost and profit. The consumer used to be the driving force for new product development, but now it appears we are being told what to like. If you don't happen to like it, your made to feel jealous or even left out with the advertising psychology these companies use. Its the same as with Apple IPhones, which are marketed as trendy lifestyle items over the shear functionality and usefulness as a tool. Even my own son has fallen for it. He finally admitted he had to have an IPhone because otherwise he wouldn't fit in at school. If these phones are so great, why don't they have sim card slots or headphone jacks? Anyways, I digress...
If someone had the capability of making an improved coax, why not try? Cone technology is the only area we've seen any advances in speaker technology. Its the weakest link in any speaker. Composites are where its at. While I love the sound of a decent paper cone, there are other substances and combinations thereof which are better. Just look at what Focal and B&W have done with their drivers.
That's an unavoidable fact about discussing anything in a public Forum 🤷🏻
I usually try to help a lot, typically offering "nuts and bolts" practical advice way beyond the typical "words/suggestions only" answers (which of course are fine and what's expected in a Forum), but now and then hold a few critical details about my own commercial products.
This excellent Forum is read all over the World, including Argentina, and I don't want to "pee against the wind" if you catch my drift.
FWIW, there are a few large VC midbass drivers which could support a decent HF driver right on top of the pole piece. It would allow for a very close time alignment and optimizing the junction between cone and HF edges. The gap here is what causes alot of issues, especially if there's a substantial air pocket trapped there.
In the case of larger pro audio drivers, there are plenty of 12s and 15s with 2.5" - 3" VCs. This would allow for placement of a high sensitivity 35mm neo HF dome. The Seas T35C002 comes to mind. It would fit in a 3" VC pole piece cavity and could be crossed fairly low.
You can also get repair components for larger pro drivers like the Eminence, so you can mix and match cones, VCs, spiders, etc.
In the case of larger pro audio drivers, there are plenty of 12s and 15s with 2.5" - 3" VCs. This would allow for placement of a high sensitivity 35mm neo HF dome. The Seas T35C002 comes to mind. It would fit in a 3" VC pole piece cavity and could be crossed fairly low.
You can also get repair components for larger pro drivers like the Eminence, so you can mix and match cones, VCs, spiders, etc.
What's up with the VC lead wires on the LF going through those tiny holes in the former? That's not a good design and could contact the former edge with greater excursion or a resonance of the lead wire itself.
Sounds alot like East Germany in the 70s and 80s. I've seen it with my own eyes. Scary
Its pretty amazing you can exchange ideas like this across most of the globe. Too bad there's always an element of censorship and control involved. I guess you have to have some rules in place to keep it structured.
@Snickers-is I agree. There are however ways around this using a smaller surround at the HF.
I remove dust caps on drivers all thr time. I usually use phase plugs for this, but even Audax did ok with their HM100Z0 mid, which had a flat, exposed pole piece instead of a dust cap. Removing that air space under the DC fixes some resonance issue as well. Dustcaps themselves cause lots of issues.
I remove dust caps on drivers all thr time. I usually use phase plugs for this, but even Audax did ok with their HM100Z0 mid, which had a flat, exposed pole piece instead of a dust cap. Removing that air space under the DC fixes some resonance issue as well. Dustcaps themselves cause lots of issues.
I'm curious......has all the various Altec/GPA 600 series duplex models in studios around the world been replaced and/or how many of their recordings remastered for improved performance?
They're all over the place IME. My former office's 2000 era Tannoy 800s were unlistenable. The 1970's 12" HPD Golds on the floor behind me, which I really like, appear to have an improperly designed tweeter correction contour. Measured response only approaches flat with paradoxically both treble roll-off and energy set to full. The discounted ~2010 DC4s bought on a whim are OK bedroom speakers with an elevated HF response.
Wouldn't mind hearing the new offerings though.
On the design I previously showed, the tweeter surround is behind the dome, so the edge of the dome is very close to the mid diaphragm.
So the surround is not terminating the dome in the conventional manner (being a continuation of the dome itself) , but is behind the dome at the domes edge? Just trying to get my head around that dome suspension you describe.
If you look at the 3rd edition of Toole's book, pg. 458-460, I think you'll find that Toole pronounces the Altec 604 and its successors as having strong "personalities" and I believe he references defects in the polar response of these drivers that preclude equalization to correct this driver (including the UREI 811B), a company that Harman owned in the 1980s. I assume from this that these monitors have gone "out of style". I have read in multiple places that the 604s and UREIs are basically all gone from mixing or mastering studios, with a few exceptions.
However, one should note that many of the biggest album-oriented rock albums of the 1970s and early 80s were mixed on these loudspeakers. While they may have a "sound of their own", I didn't detect it as being particularly obvious, in fact just the opposite, I find them to be much less strident and less "bass shy" than the albums that were at least translated using NS-10M Studios, which do seem to have their own signature sound.
So to address your question, my understanding is that all of the Altec 604-based studio monitors have been replaced in mastering studios, and most replaced in recording/mixing control rooms. YMMV.
Chris
You can mount a tweeter before the driver. Doing so it was clearly audible that time coherence is better than being "far away" (=classically above the driver).
Frequency response could be flatter than in rear mounted coaxial. (but not with the shown box, never measured it).
Here a fullrange driver I built with two piezo tweeters put before the cone.
Tweeters and driver paper cone with diy aluminium foil on it.
Frequency response could be flatter than in rear mounted coaxial. (but not with the shown box, never measured it).
Here a fullrange driver I built with two piezo tweeters put before the cone.
Tweeters and driver paper cone with diy aluminium foil on it.
We have to have three more threads or something before discussing making a better coax!. Let me know when that punish is over
Like this:
So there is a copper sleve an an aluminium ring. They are stationary, part of the motor, so the suspension landing is on the aluminium ring. The actual dome looks a bit different than in this drawing.
Best friends can be alot like high sensitivity speakers. They're fun to be around and hang out with, but they have some bad traits which can make them difficult to get along with. As with applying EQ to make speakers sound better, you can tell your friends to behave sometimes. However, under that thin veneer of compliant behavior lurks the same character traits that can really @#$! you off. Thats really how these big high sensitivity drivers are - interesting to listen to, but badly behaved in some ways.
On the other hand, low sensitivity drivers with smooth response and highly dampened cones usually sound boring, just like that well behaved, boring friend that never gets into trouble.
Most of the modern studios now use better monitors than the old Altecs and JBLs. Thats mainly because the younger engineers and producers are used to more modern monitors. The NS10Ms are still popular because they do a good job of coveying whats there in a non-flattering way. Auratones are like this as well. You just want to hear what's there without any sugar coating, even if the FR balance is off. They do however have smooth phase response and use sealed enclosures, so there are no surprises in what you hear from them. Yes, if you're not familiar how they translate a mix, you'll likely mix bass heavy and with a shy midrange. I hate mixing on NS10Ms because they can really burn your hearing out quickly. I'd rather mix on Dynaudio BM15s or JBL 4431s. In most larger studios they would typically have NS10Ms, Auratones and big JBLs. That would cover most people's needs.
Those old Altecs don't work that well for mixing critical music. They have lots of phase issues in the mids and exaggerated lower mids. The other issue is consistency, which isnt really guaranteed with vintage type speakers in various states of disrepair. The only recollection most of these new guys have of the older monitors is how worn out they sound. Most of them will never have heard newer sets of Altecs which haven't been beaten up yet.