You’re using a 16 ohm woofer and a 16 ohm 375 mid range driver on a 2397 Horn correct? Ideally you would use a 2405/077 tweeter with them. If that’s the case I would start out with this network.
Widget
You’re using a 16 ohm woofer and a 16 ohm 375 mid range driver on a 2397 Horn correct? Ideally you would use a 2405/077 tweeter with them. If that’s the case I would start out with this network.
Widget
JBL has had an interesting past with their impedance ratings... if you care, do some searches and you can get more info. Suffice it to say that all OEM 2405/077s are the same and the rating lies between 8-10 ohms.
http://www.audioheritage.org/vbullet...ll=1#post62922
You should experiment to find the best location.
Widget
This is so incredibly helpful - thank you as always Widget.
wait so if this is the case, for a 32ohm d130 - was it really 32ohm? Or was it approximately the same as the 16?
i have an older 32ohm which measures similarly with a multimeter to my 16ohm d130.
or perhaps I’m not measuring correctly?
So after reading this post I could stop thinking about whether my d130 was original or had been reconed.
the cone on these d130’s are not smooth like the others I’ve seen - so immediately I wonder if this was reconned?
I did another reading and it seems to jump around as it only has posts and not the spring clips. But the reading seemed to jump between 13 and 9/8.6 depending on how I made contact with the posts.
Also, if the posts are unmarked, is there a way you can tell which post is positive and which is negative?
DCR readings taken by using a standard DMM don’t tell you much about a driver. At best they give you the hope that a driver is working. For the most part they don’t tell you how well. That said, a jumping reading could be an indication of a problem with your meter, the leads, or the device under test.
That is definitely not the original cone for a D130. Also those are very old frames… too bad they have been turned into musical instrument speakers… most likely D140s. Due to their age and the fact that they probably have been driven hard, they should have their magnets recharged.
In my first post on your thread I said, something to the effect that assuming your speakers were in tip top condition was a big assumption. Based on these images, I would say that it is highly unlikely that your speakers will be up to spec, not to mention we don’t even know what spec they should be. If the 375s have a similar past, they probably won’t be up to spec or perform as a matched set.
If these were my parts, I would thoroughly test them and verify their status before spending any more time or money on the project. Since you are new at this, you need to get help from someone with experience and test equipment.
Widget
rats!
I knew it. I know, the frames were so nice - it was actually specifically the ones I was I looking for. Is there even a point in salvaging these old frames? Although these were an early purchase, luckily I paid around a $100 for these so it’s not extremely devastating.
I do have another 16ohm d130 that has the smooth cone and reads steady. Do you know of a place in NYC or NY area that you could recommend to get these components tested?
Hi Widget,
I ended up putting together the d130 16ohm/ 2441/2397 horn combo. The crossover I had was a n1200 - but that the previous owner who used to be a JBL tech, tested and claimed to be operating to spec. Also the d130 was different one (16Ohm) from the one I posted pictures of.
I figured if all went well, then I could hear combination crossed over at 1200hz like you had recommend - just to get an idea.
And boy did it work. To be honest Im now really regretting I decided to just make a mono system — but I think it was my apartment that decided that.
I played for hours all the 78s and mono pressings I had - then moved onto the mono cds I had. Couldn’t get enough.
wanted to just thank you for the encouragement and recommendations. My setup is not ideal as the box is a bit too small, but I think this will be a placeholder until later.
Now that I know the components are working, I’m hoping to build the crossover design you shared and add a 077 tweeter.
even as IM writing this, Im still thinking about how profoundly beautiful the sound was even from my single 2 way speaker.
thank you again!
Or you could take the easy way. I have a pair of 3115s (not A's) I would part with.
Widget,
out of curiosity - does the crossover point change if just the horn is changed but the woofer,mid driver, tweeter remain the same?
For example instead of the 2397 smith horn you use a 2309-2310 horn lens combination? Is there a different quality of sound that comes from the 2309-2310 than from the smith horn?
thank you in advance yet again-
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