May GPA 604 new unit be a replacemen in a Urei 813B without changes to the crossover

[MerlinVSM]

Will the GPA604 new units be used as a replacement in the Urei 813B without any changes to the crossover.
I assume there is correction in the crossover in 813B for the frequency "spike" at about 4kHz. I that correction
necessary with a new GPA unit ?

[Horn Fanatic]

Hands down, IMHO, the GPA 604-8H III is far superior to the earlier models. The new horn Bill designed a couple of years ago coupled with the Radial phase plug produces more information flat to 20K than the 604-8G ever could.

However, I would readdress the box tuning for the new 604, as I would readdress the tuning of any production cabinet loaded with an ALTEC.

[MerlinVSM]

There are several iterations of the Urei 813 the 813, 813A, 813B and 813C.
Will the new GPA 604 unit be a replacement for all the above iterations/models without any change
to the crossover ?
The models use different iteration of crossover see below

urei model / crossover no.
813 / 838
813A / 839
813B / 840
813C / ?

I assume that the new GPA 604-8H-III unit is nt a direct substitute without any
changes to crossover on all above Urei models ?

Any input appreiciated

BR

[Robh3606]

I assume that the new GPA 604-8H-III unit is nt a direct substitute without any
changes to crossover on all above Urei models ?


Yes that is correct. Each crossover was set-up for each specific driver set. They are not interchangeable. You would have to get a measurements set on the GPA and try it in a crossover simulator.

Rob:)

[MerlinVSM]

Yes that is correct. Each crossover was set-up for each specific driver set. They are not interchangeable. You would have to get a measurements set on the GPA and try it in a crossover simulator.

Rob:)


Quote Great Plans Audio: "Our speaker are the same as 604K as fas as time alignment so the 829TA, 839TA or 849TA will work with or speaker."

So, the Urei 811 and 813 using these crossovers can use the GreatPlainsAudio 604 unit without any Changes the crossover I assume

[MerlinVSM]

Quote Great Plans Audio: "Our speaker are the same as 604K as fas as time alignment so the 829TA, 839TA or 849TA will work with or speaker."

So, the Urei 811 and 813 using these crossovers can use the GreatPlainsAudio 604 unit without any Changes the crossover I assume


However, does the GPA604-8H-III mechanical parameters also make it a direct replacement/substitute for the 604 unit in the Urei 813A (incl. the 839TA crossover)


Anyone, please, confirm.