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View Full Version : Can you substitute the O77 8ohm diaphram with a 16ohm from a 2405 slot?



vinny
06-30-2017, 04:35 PM
meant can you swap 8 ohm for 16 ohm diaphram and my other question is, would it still retain the sweet sound the 77 is known for the only difference being 16ohm impedence? Thanks

1audiohack
06-30-2017, 05:08 PM
Yes you can. They are actually identical no matter what the foilcal on the driver says.

Barry.

vinny
06-30-2017, 10:16 PM
Yes you can. They are actually identical no matter what the foilcal on the driver says.

Barry.

Thanks Barry so the 077s are 16ohm impedence regardless if it says 8ohms on the foil? So i dont have to change the diaphrams on the ones i got to 16ohm diaphram which i wanted to do.

1audiohack
07-01-2017, 12:22 AM
Right. You wont need to swap the diaphragms. Actually the AC impedance is right about 12 Ohms on all of them.

Barry.

vinny
07-01-2017, 07:08 AM
Right. You wont need to swap the diaphragms. Actually the AC impedance is right about 12 Ohms on all of them. Barry.Thanks i will use these 077s on my unique 16ohm setup. 175 Le15a and add 077. Just looking for the right crossovers and trying to find the correct plans to build the right boxes for them. Barry what do you know about the 076 cats eye bullet? Anything special sonically speaking?

vinny
07-01-2017, 07:35 AM
Barry if you dont mind the extra questions. Are you familiar with the LE15 woofer? One came with foam surround 16 ohms and the other i seen in L200 system paper accordion surround at 8 ohms. Would that 8 ohm le15 still be 16 ohm regardless? I want everything 16ohms in my new project thats why asking. Lastly whats the perfect crossover for the le15a 16ohm..thanks agaian

1audiohack
07-01-2017, 07:44 AM
Hi Vinny;

I don't mind at all but that's a question I don't have an answer for. Hopefully someone that knows will chime in.

All the best.
Barry.

Mr. Widget
07-01-2017, 10:56 AM
Barry if you dont mind the extra questions. Are you familiar with the LE15 woofer? One came with foam surround 16 ohms and the other i seen in L200 system paper accordion surround at 8 ohms. Would that 8 ohm le15 still be 16 ohm regardless? I want everything 16ohms in my new project thats why asking. Lastly whats the perfect crossover for the le15a 16ohm..thanks agaianI'm not exactly sure what you are asking, but there are several woofers in this family. See Below.

Foam Surrounds
LE15 - 16 ohms
LE15A - 16 ohms
LE15H - 8 ohms
2215A - 8 ohms
2215B - 16 ohms

Cloth Surrounds
LE15B - 4-6 ohms
2216 - 4-6 ohms

vinny
07-01-2017, 12:03 PM
I'm not exactly sure what you are asking, but there are several woofers in this family. See Below.Foam SurroundsLE15 - 16 ohmsLE15A - 16 ohmsLE15H - 8 ohms2215A - 8 ohms2215B - 16 ohmsCloth SurroundsLE15B - 4-6 ohms2216 - 4-6 ohmsThanks that clarified things. So the le15b is not 16ohms and label not misprinted like many early jbl bullet tweeters in the past

Mr. Widget
07-01-2017, 12:13 PM
Thanks that clarified things. So the le15b is not 16ohms and label not misprinted like many early jbl bullet tweeters in the pastYes, the LE15B is not 16 ohms. The others are not misprints. There are various ideas as to why JBL printed different nominal impedance values on the exact same drivers at different times.


Widget

vinny
07-01-2017, 11:09 PM
Yes, the LE15B is not 16 ohms. The others are not misprints. There are various ideas as to why JBL printed different nominal impedance values on the exact same drivers at different times.


Widget

Thanks mr Widget if i may ask whats the ideal crossover for the Le15a and matching high frequency horn and tweeter and its matching crossover?

Mannermusic
07-03-2017, 07:22 AM
Why don't you take a look at the L300? It's a modern update of sorts of what you are considering and sounds considerably better. There are some useful threads here on site including crossover schematic (search).

Mr. Widget
07-03-2017, 10:57 AM
Thanks mr Widget if i may ask whats the ideal crossover for the Le15a and matching high frequency horn and tweeter and its matching crossover?There are too many variables for me to give you really useful info.

I agree with the poster above, the L-300 is a great starting point. If you can't get those parts all lined up then try cloning a JBL that has the parts you do have.

In my opinion JBL has gotten better and better over the decades so a newer design will likely offer better results, though there is a lot to like from each decade.


Widget

vinny
07-07-2017, 01:25 AM
There are too many variables for me to give you really useful info.

I agree with the poster above, the L-300 is a great starting point. If you can't get those parts all lined up then try cloning a JBL that has the parts you do have.

In my opinion JBL has gotten better and better over the decades so a newer design will likely offer better results, though there is a lot to like from each decade.


Widget

thats not what i been hearing from the groups that ever since 1979 when they went to ceramic magnets and cut costs they regressed and tTad has blown right past Jbl in construction and sonic quality. Its now relegated to mediocre stature in their drivers. Paradigm even makes better drivers than modern jbl which is just living on its past reputation.

Mr. Widget
07-07-2017, 08:48 AM
thats not what i been hearing from the groups that ever since 1979 when they went to ceramic magnets and cut costs they regressed and tTad has blown right past Jbl in construction and sonic quality. Its now relegated to mediocre stature in their drivers. Paradigm even makes better drivers than modern jbl which is just living on its past reputation.Yep, same thing happened to Ford after the end of production of the Model A. It's been a downward spiral ever since.


Widget

edgewound
07-07-2017, 10:24 AM
thats not what i been hearing from the groups that ever since 1979 when they went to ceramic magnets and cut costs they regressed and tTad has blown right past Jbl in construction and sonic quality. Its now relegated to mediocre stature in their drivers. Paradigm even makes better drivers than modern jbl which is just living on its past reputation.

Vinny,

There's a lot to dissect in your commentary. While TAD might have "blown passed" JBL in product quality...which by the way, was borne out the mind of Bart Locanthi...JBL has been a company that has always made the best products possible within budgetary constraints. Pretty remarkable to do that kind of high-end engineering when you have to do the best you can with what you've got...and still sell product to stay in business.

TAD gave Bart Locanthi a blank check to make the best transducers possible, cost no object. A dream job for a physicist/engineer. Mr. Locanthi wanted to do the same thing with JBL technology, but management at the time knew the market they were playing to and made the very smart business decision to stay the course.

1979 was a very unique time in audio history for the supply of cobalt for loudspeaker magnets. Supply was very limited due to civil war in Africa, the main source for cobalt, and became very expensive and difficult to procure. Ferrite magnets took over for AlNiCo due to necessity. The engineering team at JBL worked tirelessly to come up with a new magnetic circuit using ferrite. The result was the Symmetrical Field Geometry motor, and is actually a better performer than it's predecessor, AlNiCo. The four advantages that the AlNiCo motors have over the SFG motors are lighter weight, self shielding, harder to break, and well, AlNiCo is a rare earth element which just makes it plain sexier. That said, the SFG actually performs better...for way less cost to the end user.

The audio market has changed with demographics. We just might be in a cyclical downturn for the Millennials and GenXers while they mature and start to appreciate the merits of fine audio systems...or maybe not. We live in a very technologically disruptive time where each market segment gets sliced thinner.

We shall see. Will the acquisition of Harman by Samsung be a boon to Samsung by looking at the telematics business? Or will it have been a mistake as populations are encouraged to get out of their own cars in favor of mass transit and ride sharing?

Meanwhile, high end audio is shrinking into a cottage industry with smaller players filling the void.

1audiohack
07-07-2017, 07:31 PM
Yep, same thing happened to Ford after the end of production of the Model A. It's been a downward spiral ever since.Widget

That's funny, that is what I was thinking nearly to the T.

I have a pair of TAD TM-1201's in my 4350's and OMG! they have ferrite motors! I must concede that they are absolutely incredible.

I don't know how anyone who has actually truly objectively listened to the top and second tier JBL speaker systems made in this century could possibly draw the conclusion that the old days were the best. Still owning some prime examples from both centuries my opinion is firm.

Is there really any debate that the 1501-XAl is not the finest HiFi woofer on the planet?

Nuff said.

Barry.

Mr. Widget
07-08-2017, 12:30 AM
thats not what i been hearing from the groups that ever since 1979 when they went to ceramic magnets and cut costs they regressed and tTad has blown right past Jbl in construction and sonic quality. Its now relegated to mediocre stature in their drivers. Paradigm even makes better drivers than modern jbl which is just living on its past reputation.Ok, my last response was tongue in cheek, but seriously there is so much ignorance and mis-information on the web that finding fact from fiction can be difficult.

For facts on JBL's need to move away from alnico to ferrite in the late '70s, read this:

http://www.audioheritage.org/vbulletin/showthread.php?4031-The-Great-Alnico-Ferrite-Debate

As Edgewound suggested, TAD's mission was to build the finest drivers possible and cost was of little consequence. I'd argue this was in the vein of James Lansing himself, but then he bankrupted the company and the businessmen who took over the company struggled to keep one eye on this philosophy and the other on cost. That said, TAD has always been a boutique product producing a tiny number of speakers compared to JBL. Since 2003 they have discontinued over half of the woofers and five or six of their HF drivers. Currently they only offer four models of woofers and either two or three HF drivers. Typically when you place an order you have to wait about six months for them to produce them... now that Pioneer has been purchased by Onkyo I doubt the TAD pro drivers will be around much longer.

As for JBL currently only making mediocre product, that is nonsense. They produce metric tons of landfill product to be sure, but that is the low cost JBL Consumer gear sold on-line and elsewhere. And sure, they are using the good name of JBL to help sell it, but I'd argue the typical purchaser of $50 headphones has never heard of JBL. In any case JBL Pro and JBL Synthesis are arguably producing some of the most advanced drivers and systems in the world. The fact that most people are unaware of this does not make it untrue.


Widget

pos
07-09-2017, 06:52 AM
Thanks BMWCCA for pointing (http://www.audioheritage.org/vbulletin/showthread.php?39875-Has-Tad-overtaken-JBL-in-build-quality-and-sonic-superiority-years-ago&p=406963#post406963) me to this thread :)


I have a pair of TAD TM-1201's in my 4350's and OMG! they have ferrite motors! I must concede that they are absolutely incredible.
So you did replace your 1200Fe with them?
This is an impressive driver indeed, perfect for that range. More tamed than a 2020H (I know this is one of your favorites), but also more neutral IMO.
You should absolutely try current drive amplification with them, I think your amps can do this IIRC! :bouncy:

1audiohack
07-09-2017, 07:29 PM
Hi Thomas;

I did excange them last weekend. I now wish I had done this long ago.

In my opinion a 12" midbass-midrange driver is one of the strengths and one of the weaknesses of the 4350. Dynamics are stellar, integration is difficult.

I tried the 1200Fe in attempt to lower the 15's into near sub territory but the dogbox for the 12 pretty much drives the results from about 200Hz and lower. The 1200's sounded nice so I just left them. Different EQ requirements of course. As a note, it looks to me like the 1200Fe and the 2020 use the same motor.

Several things stacked up to require changes to the 4350's. I excanged the 1501-1AL's back to the 1500AL's, inadvertantly locked myself out of the dbx4800, and was still never happy with the implementation of the 12's and it seemed a shame to have the TAD's just sitting in boxes so I hard reset the dbx and got started.

With the old (haha) 1500AL's the VLF required a little EQ work, the TAD's? None, none at all. A little out of band filter work on the top and they look like an electrical filter measurement.

The results are the best ever for the 4350's with a couple of audio buddies exlaiming that the 4350 system is my best system of all.

Now that I have totally smashed vinny's thread, sorry Vin, I should mention I also I used a different measurment method. This deserves it's own thread.

Barry.

pos
07-10-2017, 08:55 AM
Haha, this TAD discussion now spans three (http://www.audioheritage.org/vbulletin/showthread.php?39882-Multi-Mic-Measurment-Method) different (http://www.audioheritage.org/vbulletin/showthread.php?39875-Has-Tad-overtaken-JBL-in-build-quality-and-sonic-superiority-years-ago) threads (http://www.audioheritage.org/vbulletin/showthread.php?39859-Can-you-substitute-the-O77-8ohm-diaphram-with-a-16ohm-from-a-2405-slot) :D