what is the difference ?

**tonino** · August 11th, 2009, 11:07 AM

hi All,
I am interested to buy a new 604 and i would like to know what are the differences between the Iconic 704-8 A and the Great Plain 604-8-III and also between the 604-8-III and the 604-8-II . Thanks in advance
Tonino

**chrismercurio** · August 11th, 2009, 12:35 PM

I can't speak to the Iconic vs the GPA Series II which both use the same MantaRay horn.

From a buddy that has both the GPA Series II and Series III and has used them both in a big MLTL:

The two big differences are the highs, which are noticeably more extended and airy with the III's and the dispersion pattern which is vertically much narrower. For my room this dispersion which is the same horizontally but narrower vertically was an unexpected and huge improvement.I have lots of glass on the back wall and now room interaction is much less of an issue. Less mid/high floor bounce too. It makes the speaker "disappear" even more since the mids and highs sound more solid and resolved.
The II's are still great but the III's really refine the sound and basically make this a true full range speaker. I am now getting reasonably flat response from 25hz to 20khz

**gortnipper** · August 11th, 2009, 04:22 PM

The Iconic 704-8 A is a GPA 604 8H II that uses an Iconic crossover, and a different diaphragm in the horn (made my by GPA) with a higher power handling capability.

**tonino** · August 12th, 2009, 05:39 AM

Hi,
thanks for you answers.
Now i have a pair of 604 D. How mutch a new driver as 604-8-III or Iconic 704-8 A can improve the sound ? The 604-8-III or Iconic 704-8 are also different regarding the crossover ? Thanks again

Tonino

**Old Guy** · August 12th, 2009, 09:26 AM

I am not as experienced with the 604D as I am with the early ones and the later "G" models...

But the 604D is a fine speaker. If the Alnicos are fully charged, the only place a real improvement on the speaker could be made is the horn. I don't care for the small multicell.

Crossover is a different story. If you do a forum search here, you'll find links to better DIY crossovers, as well as many other ideas.

The stock 604 crossover needs improvement. I would think about that, rather than getting new speakers, and just make sure all is working well on the speakers, ie magnets, frams, etc

**tonino** · August 12th, 2009, 10:06 AM

Hi,
thanks for your reply. Yes magnet is charged and about crossover I will order a new DN604ES1A1 super crossover from Iconic.
About horn I am just compare this ( Coaxial ALTEC 604 ) that I buy to the multicellular horn that I damped with Harmonix RF 57 MK II ( Harmonix Interconnect Cables) that are tuning devices very impressive at my opinion. They change the sound of the multicellular horn in a more natural way .
Tonino