Apogee Midrange ribbon help

tjc123057

Member
2013-03-24 4:48 pm
Hi, I am a new member as of today. I have a pair of 1992 Apogee Divas. Like others on this site have posted, you can no longer get to the old Apogee posts to find very useful info. I have read many posts on dyiAudio and can see there are a lot of people very knowledgeable on Apogee subjects. I hope someone can help me with a question. I have had to replace my midrange ribbons at least 9 different times in the last 20 years, as a pair, because I like to play music loud. When Apogee sold the replacement ribbons they were only $60.00 a pair. Now they are about $320.00 a pair. I bought a lot of spare replacement ribbons from Apogee, Graz, and Robert Darangus but I didn’t keep them separated. Whenever I replaced my ribbons in the past they ALWAYS measured about 3.0 ohms each. As the Apogee Acoustic’s replacement literature states they should measure. I just replaced both midrange ribbons this weekend and they only measure 1.67 and 1.78 ohms. I checked and double checked and I installed them correctly. No shorts. My question is; will the lower resistance degrade the sound of these wonderful sounding speakers. Will they "burn out quicker" I now believe/imagine the midrange is now louder and not as full soundings, like it is playing at a higher frequency. I do not see any more movement than normal from ribbons when playing music. I am using an active crossover at 500 hz 6 db, as I have been, so I know the lower resistance isn’t affecting the crossover point like it might in a passive crossover. Any help will be greatly appreciated.

If anyone needs pictures of Divas apart let me know.

Thanks,
Tom
 

tjc123057

Member
2013-03-24 4:48 pm
These are very early Graz ribbons and they are 1.8 ohms. Graz and I talked several times and I sent him samples of my midrange ribbons when he first started up. I have 4 pair of Graz ribbons and they all average 1.8 ohms. I have 2 pair from Apogee and they are 3.1 ohms. I should have measured before I installed them. But I wouldn't think the sound would be bad on the 1.8, I just need to turn down volume on mids. I have the Dax 1 with modified passives and a pair of non modified passives as well. I would be afraid to use the non modified passive now with only 1.8 ohms.
 
..... I have had to replace my midrange ribbons at least 9 different times in the last 20 years, as a pair, because I like to play music loud. .........

You have realy a lot of broken ribbons, average one per 2 years. Mine, on Stages lasted nearly 15 years. I think, you should increase the slope, btw I am using 24L/R slope at 500Hz and 84Hz on my tri-amped system (Stages + subs).

Secondly, do you have big capacitor for protection on MRT?
 
noone bothering the fact that 1.8 ohm means complete other crossover as well???


its like almost crossed one octave higher then before with the 3 ohm.. so yeah ur previous would sound warmer because its crossed lower.. now ur ribbon wil last longer:) but your amplifier may not.


for instance ur 3 ohm is crossed at 1000 Hz, with 1.8 ohm ribbon with the same passive crossover it will be around 1700Hz


if ur fully active my message is ofc not true :) then just reduce the output by 5 or 6 db and it will sound as it should. (not taking in to acount the ribbons are diferent so it may sound diferent even if the impedance is the same)
 
Last edited:

lscangus

Member
2005-10-16 9:52 am
Hello all!
I have just aquired a new pair of Divas Post 10360. Which has the modified crossover catered for the DAX. I am only planning to power it with single amp.

I wonder if i can have the original schematic of the corrosver of the divas?

Also, are there any documents in doing up the tension of the ribbons?

Thank you so much! thanks for your help! I am going to replace all the ribbons and it would be great to get some advice from some senior members.