A professional license probably is the main difference.

The use of "architect" and "architectural" in job titles is equally regulated by licensing statutes in most places, so I don't think it has to do with whether or not you have a license.

Based on how I've seen these used, I would guess that an Architectural Designer is somebody who does design work on the project team, while the Design Architect is likely the lead designer of that team. But that's just a guess. These sorts of titles vary hugely from firm to firm.

yawn....titles...

It really depends on the usage of the terms. But the most
likely distinction would be that an Architect has passed the registration exam.
A very rigorous exam administered by the NCARB. (some Architects use this as a
suffix to their name) This test is not one that measures design skill. It test
critical and technical knowledge related to the practice of architecture. The description
most often used is that the ARE tests a candidate’s knowledge to ensure health,
safety and welfare. 

An architect is licensed by passing this test. It is very much the equivalent
to the Bar examination for the legal profession. The test is 7 parts and each
part ranges from 3-6 hours per test. Some take this exam over a period of time
(weeks to months). The passing rates for the exam are fairly low. (some section
in the 40% range) So to pass this test, you are required to be very knowledge
about much more than just architectural design. I would wager that most who
have passed this test would never call themselves an '"architectural
designer". They have worked hard to achieve the title of
"Architect". Someone who has passed this exam may have several
suffixes to their name:

AIA - Means they are a registered/ licensed architect who is a member of the
professional organization American Institute for Architects (aia.org)

RA - Means they are a registered/licensed architect. RA= Registered Architect.
They have passed the exam (may be a member of Society of American Registered
Architects, SARA) 
 
NCARB - They are accredited by the National Council of Architectural Registration
Board. They have passed the exam and maintain their accreditation with NCARB 

Now an "architectural designer" may have the exact same education,
training,  etc. as the above architect. But this person has not taken or
passed the registration exam. They cannot provide a set of "sealed"
documents that are required by many municipalities to get a building permit for
a construction project. They may have been in the architecture profession for
many, many years or just came into the profession and have a degree in design.
But they may not. The use of the terms architect and architecture are usually
well governed, but depending on your location, architectural designer may be
acceptable to describe someone with little to no architecture education. This
will vary by location. 

All of this is not to say that an "architectural designer" is not
capable of doing a job as well as an "architect" but the designer has
not had to meet a certain set of qualifications and education to hold the title
of "architect". And depending on your needs, both of these can
provide you with services. I, being a registered architect, would prefer
someone to select an "architect" for all their project needs.

^disagree.

Like gwharton said...

The use of "architect" and "architectural" in job titles is equally regulated by licensing statutes in most places.

Based on my experience, architectural designers are largely just  people willfully ignorant of the illegality of their title because they can't stomach the word "intern" or anything more abstract. It's often not even descriptive of their professional roles, as they tend to be more jr. and often more development/production oriented.

Design Architect... I've never heard anyone call themselves this before. Probably just an architect who wants to make sure everyone knows what part of the profession they are focused on.