2225A vs 2205H vs 2225H

I was looking at specs sheet for those three drivers. What jumpe to my face was the different Fs values. 30Hz for the 2205 and 40Hz for the 2225. That's a big difference and I always wondered how the sound was altered when switching over to the 2225 generation on rear loaded horns...

2205h
http://www.google.ca/url?sa=t&rct=j&...blBwcPqeKD_tFw

JBL 2205a
http://www.lansingheritage.org/image...2205/page2.jpg

JBL 2225h
http://www.google.ca/url?sa=t&rct=j&...TFwHA_BSubjksw

Sure, the 2205 is only rated at 150W vs 200W for the 2225, but it should be expected if the 2205 goes 10Hz lower. I am thinking looking for some 2205 to replace the current 2225 in my JBL 4520s. After all, those were designed for 2205...

Thoughts?

Lee

Hi Lee;

Going out on a limb here, I don't get too hung up on Fs on some applications. If you sweep a LF driver in free air connected directly to a low impedance real power amp, visually you can not tell where Fs is, the amp is by far the controlling "strong force" in the system. True horn loading is another "strong force" that can virtually negate a drivers Fs when the assembly is run or measured under power as a system. I have never had or horsed around with scoops but in a true horn loaded system driven by a real power amp my experience is that the speaker/driver is going to do what the amp tells it to and what the horn allows it to do and the "weak force" of cone/suspension, Mms/Fs is going to be all but invisible on the low end.

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Originally Posted by Lee in Montreal

I was looking at specs sheet for those three drivers. What jumpe to my face was the different Fs values. 30Hz for the 2205 and 40Hz for the 2225. That's a big difference and I always wondered how the sound was altered when switching over to the 2225 generation on rear loaded horns...

2205h
http://www.google.ca/url?sa=t&rct=j&...blBwcPqeKD_tFw

JBL 2205a
http://www.lansingheritage.org/image...2205/page2.jpg

JBL 2225h
http://www.google.ca/url?sa=t&rct=j&...TFwHA_BSubjksw

Sure, the 2205 is only rated at 150W vs 200W for the 2225, but it should be expected if the 2205 goes 10Hz lower. I am thinking looking for some 2205 to replace the current 2225 in my JBL 4520s. After all, those were designed for 2205...

Thoughts?

Lee

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JBL designed the 4520/30 and they used the best driver they had at the time AKA 2205. When the 2225 came it was used.
In one system I made I used 2226 in 4530 scopes and the bass was stunning.
A long time ago I built a pair of C40 home style rear loaders and used D140F for the driver.
With any horn loaded bass you do need to careful of Hz below the cut Hz of the horn as the driver becomes unloaded and can damage the driver.

The difference hasn`t any effect because of the low cut frequency of the horn.
Maximum load is 30 Hz (4520) and 50 Hz (4530). You may use driver with higher Fs.

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Originally Posted by paragon

The difference hasn`t any effect because of the low cut frequency of the horn.
Maximum load is 30 Hz (4520) and 50 Hz (4530). You may use driver with higher Fs.

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The 4520 loks like it has an 8ft horn length, which is 35Hz at 1/4 wave. Using a 2205 in these make more sense than in the 4530 (7ft = 40Hz)

Waldorfs have TAD 1603 drivers with Fs30 while the cab has a 40Hz horn. But as the back chamber is huge, it must probably help use the lower Fs.