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View Full Version : 2405: Real difference between 8 Ohms and 16 Ohms..



eziodoc
09-30-2008, 03:57 PM
Hello friends,
do exists or you know real differences, in terms of sound quality, between the two 2405 tweeters, at 8 Ohms and 16 Ohms?
Sorry if the thread was discussed, but not seen by me..

Thanks.
Ezio

Robh3606
09-30-2008, 04:08 PM
No none at all.

Rob:)

Mr. Widget
09-30-2008, 05:23 PM
No none at all.Not only are there no sonic differences, there is no difference except for the printed label. All 2405s and 077s are the same. They are approximately 10 ohms.


Widget

Beowulf57
10-06-2008, 07:49 AM
If the diaphragm has been replaced with an aftermarket model at some point, the impedance may be different from the original JBL. For example if an "8 ohm" JBL diaphragm was replaced with an "8 ohm" aftermarket model, that diaphragm may actually have a DCR of 3.2 ohms, rather than the ~6.2 ohms of the original.

Mr. Widget
10-06-2008, 09:23 AM
If the diaphragm has been replaced with an aftermarket model at some point...If the diaphragm is aftermarket, who cares what the impedance is... in my opinion it is no longer a 2405. It will almost certainly not perform as specified.


Widget

Rolf
10-06-2008, 11:40 AM
If the diaphragm is aftermarket, who cares what the impedance is... in my opinion it is no longer a 2405. It will almost certainly not perform as specified.


Widget

Agreed!

Beowulf57
10-06-2008, 12:00 PM
If the diaphragm is aftermarket, who cares what the impedance is... in my opinion it is no longer a 2405. It will almost certainly not perform as specified.


Widget

I simply wished to inform him of the possibility that he could end up with an "8 ohm" unit that might not be identical to an original "8 ohm" unit.. Now, he has at least one method of checking and that is why I cared.

mvaldes
10-11-2008, 09:34 AM
Hello friends,
do exists or you know real differences, in terms of sound quality, between the two 2405 tweeters, at 8 Ohms and 16 Ohms?
Sorry if the thread was discussed, but not seen by me..

Thanks.
Ezio

Ezio,
on the "VideoHifi" forum I gave you the same answers you got here....
Hope you'll enjoy your 2405 with peace of mind, regardless the impedance label...
cheers
:)


Michele

boputnam
10-11-2008, 05:15 PM
Not only are there no sonic differences, there is no difference except for the printed label. All 2405s and 077s are the same. They are approximately 10 ohms.Yessir.

And, if you ever have a doubt about such things, take out your multi-meter and measure the DCR of each. It's a good idea anyway... ;)

scott fitlin
10-12-2008, 03:19 AM
i dunno, I always thought Alnico 075 bullets had a slightly softer top end sound.

However, I use ferrite 2402H, and they are CRISP, and INCIIVE, so, I never thought about alnico.

Conversely, I love Alnico mag, Aluminum diaphragm 2in drivers, maybe the phragm material more than anything?

Now, recently, I heard two setups, one with 2446J, Ti phragms, and another, same company, 2450J, neo mag Ti phragms, 2446 sound goood. 2450J was really good, guy uses crown Power L<ine Four amps for comp drivers, 2450J sounds great witgh todays sxource material, becausze IT handles MORE power than my sweet, older 2 in drivers.

Remains smooth, with sharp image, no breakup or ring at high SPL levels, using higher power.

I also heard the 2446 going all the way up, no tweeter.

Im not sold on that, yet. Still like tweeter to go the distance high. Delicate top. 24456 goes up, but kind of like driving a Caddillac Escalade like you think its a BMW M3. You can sort of, but ......... not really.

Although, I have modernized considerably, and with very positive results. I don't miss what I have taken out.

The NEW stuff can and DOES work.

I KNOW! Im recanting everyhing I have always said, but...... oh well.
:)

robertbartsch
10-23-2008, 11:46 AM
I prefer the new professional drivers and networks over the vintage stuff.

...hope I don't get flamed here - yikes!

Hoerninger
10-23-2008, 12:33 PM
]...hope I don't get flamed here - yikes!
Why should this happen? :)

I prefer the new professional drivers and networks over the vintage stuff.
This new gear is simply working. There is no need for repair so far, there is no need to mention in a Heritage Forum.
But the new gear can give hints for improvements. ;)
___________
Peter

Robh3606
10-23-2008, 01:21 PM
I prefer the new professional drivers and networks over the vintage stuff.

...hope I don't get flamed here - yikes!


What's wrong with that it's all JBL??

Rob:)

robertbartsch
10-23-2008, 01:54 PM
http://www.theaudioauction.com/index.php?a=2&b=2247


^ This dude has two hundred 18" JBL 2240H carcasses to sell, so apparently, a few "new" profesional series JBL drivers are in need of repair.

Anyway, I've been looking for a used JBL 2206H (12 inch woofie) for a while on Flee-Bay but I do not see any. Oh well, I'm sure one will show soon, I suppose.

Zilch
10-23-2008, 04:48 PM
This dude has two hundred 18" JBL 2240H carcasses to sell, so apparently, a few "new" profesional series JBL drivers are in need of repair.No, that's what replaced them, obviously.

We DO, however, know what to make outta those.... :thmbsup:

eziodoc
10-26-2008, 07:44 PM
Not only are there no sonic differences, there is no difference except for the printed label. All 2405s and 077s are the same. They are approximately 10 ohms.


Widget
Hi Mr. Widget,

sorry for my stupid question, from a no techinician JBL user: having a pair of loudspeakers with the 2405 (4343's, 4345's),
I can to replace them with a pair of 077's crystal tweeters, without electric/sonic problems?

Thanks.
Ezio

eziodoc
10-26-2008, 07:51 PM
Ezio,
on the "VideoHifi" forum I gave you the same answers you got here....
Hope you'll enjoy your 2405 with peace of mind, regardless the impedance label...
cheers
:)


Michele
Ciao Michele,
only now I seen the answers to this thread and your reply... :blink:
Thank you, my mind is in peace, but curious, and don't understand why JBL made two different stickers for same item...
Ciao e grazie.
Ezio

Mr. Widget
10-26-2008, 08:03 PM
Thank you, my mind is in peace, but curious, and don't understand why JBL made two different stickers for same item...We can only speculate, but back in the '60s most systems were 16 ohms to better mate with tube electronics later 8 ohms became the favorite to better mate with solid state... the 077/2405 will work well with both, but consumers don't always understand that sort of thing.


I can to replace them with a pair of 077's crystal tweeters, without electric/sonic problems?Absolutely... there is no sonic difference.

Widget

eziodoc
10-26-2008, 09:34 PM
We can only speculate, but back in the '60s most systems were 16 ohms to better mate with tube electronics later 8 ohms became the favorite to better mate with solid state... the 077/2405 will work well with both, but consumers don't always understand that sort of thing.

Absolutely... there is no sonic difference.

Widget
....also electrical absolute compatibility?....:)
So I can replace a pair of 2405's 16 Ohms wit a pair of 077 8 Ohms, without any problem?

Thank you for all answers..
Ezio

Mr. Widget
10-26-2008, 10:22 PM
....also electrical absolute compatibility?Yes, yes, yes!!!

There has always only been one diaphragm for both of these drivers. JBL has never sold an alternative for the 077 and 2405. They have always used the exact same unit. The only difference between the 077 and any alnico version of the 2405 is that the phase plug is clear acrylic on the 077 and is painted aluminum on the 2405.

There is a newer ferrite version of the 2405, it is called the 2405H. Some people believe this version sounds different from the earlier alnico versions. I have not heard or measured any difference.


Widget

mvaldes
10-27-2008, 02:47 AM
Ezio,
are you planning to replace the 2405 with 077 on you 43xx?
If you want to know my opinion, I would say: don’t do it!
I have a pair of 077 (alnico), a pair of 2405 (alnico) and a pair of 2405H (ferrite)
I’ve tried to swap the 2405 alnico on a pair of 4333A with the 077, and I can’t hear any difference.
I know that there are people that claim that 077 sound much better, but this is just not true.
As had been already stated by Widget, there is no any difference between 077 and 2405 or between any 2405 version.
If you are not satisfied of your system sound in the very narrow band played by the 2405, try with a different approach.
If I were you, I would try to change the diaphragm of the 2405 with a new one (of course an original JBL ones, not a replacement).
We are talking of speakers that are at least 20 years old. We probably bought these speakers used, and there is the possibility that the previous owner(s) didn’t pay much attention on how to safely drive them, and the 2405 is the first component that can be damaged.
Michele

PS: long time ago I owned the 4344. I’m now a “two way” upholder, and my favorite speaker are the 4430, but I’m missing the 4344 speaker now. Kind of nostalgic…..? Anyway if you are planning to sell them , drop me a line….

4313B
10-27-2008, 07:02 AM
PS: long time ago I owned the 4344. I’m now a “two way” upholder, and my favorite speaker are the 4430, but I’m missing the 4344 speaker now. Kind of nostalgic…..?Forums like this kind of feed the nostalgia. ;)