What speakers are these hanging from the ceiling?? (pictures)

[G871]

Ah I'm at work so I can't check the values right now - the cap should be labeled with a value right? And then I'd have to desolder the wires to the resistor and measure it to find the value, right? I should be able to do that later tonight.

And when you say:

The simplest way to run the tweeter is to put a 1 mfd capacitor between the + wire for the horn driver and the center leg (terminal 2) of an 8-ohm L-pad

By horn driver you mean the 2440 right? Just want to make 100% sure I understand correctly before I do anything.

 

[sregor]

So if I'm seeing this right, there's no crossover section for the tweeter. Was it removed? I'm clueless. They had tweeters hanging from the ceiling, so maybe they just disconnected all of these tweeters?? I dunno.

Most likely they were disconnected when the other tweeter array (the ones you didn't get) were installed - just a guess.

 

[toddalin]

The value of the resistor should also be printed on it. A small value cap would confirm that this was for the tweeter.

Yes, the horn driver is the 2440.

 

[G871]

Ok I'll check and get back to ya. Thank you!

 

[G871]

Ok, the cap is 52uf and the resistor is 25 ohms.

 

[G871]

Do not cut that wire on the Crown. It is a 20A plug and you can get short wires that convert from 20A plug to a standard 15A plug. One came with some Crown gear.

Excellent! That's wonderful to hear. I didn't really want to mess with it.

I was thinking more of a pic all packed up, or a couple pics of the entire haul at home once all was unloaded, a group shot!
Regardless, you have lots of fun ahead getting this all singing again

Yes I do! As long as I can get this tweeter issue figured out. And I'll definitely be taking more pictures with everything cleaned up and together. Actually planning on making a new thread at some point when I get things situated well. I'm working on getting my spare bedroom set up as my work room with a desk and table....right now 3 of 4 of these bohemoths are in my living room, just because I had nowhere else to put them when I got them home. Eventually one pair will stay in my living room, but right now since they're not being used, I have my NS-690's in front of them, and in a small room, it's just cramped. But I will make a nice organized thread with detailed pics as soon as I can.

The OM for the NAK is on HFE for download. https://www.hifiengine.com/manual_library/nakamichi/ta-4.shtml
Shows a rated output of 1V so it has regular preamp outputs and will work just fine with that VFX or PSA if you just go full range with the speaker/amp.

The TA also has two preamp outputs, one jumpered to the receiver's amp the other open to play. Good flexibility with that.

Ahh, oh so is that the only difference between the T and TA? I saw that page but wasn't sure if that manual would work for the TA as well. Thanks!

How do you feel about the drive, now that is it done?

Nice haul of some proper pro/home audio gear. What made you leave the bullets behind, funding? That is quite a stack of gear and it probably cost quite a stack of bills. But you probably did really well and will be on a steep learning curve as you figure out what is actually going to work best for you. Got any big and I mean big parties planned needing some serious tunes?

I'm totally fine with the drive. I've driven that far for lesser speakers, back in the beginning of my audio journey. Now I'm more picky, and these just felt right........but if another 2 pairs of these speakers, and the amps, popped up the same distance away for the same price, I wouldn't run and get them. Of course I have no space for them, but it also wasn't a steal. As long as I can get the tweeter situation figured out, and they sound as good as I expect them to, I'll feel like I got a good deal. I'm not overly concerned with resell value....I really just want them to be so amazing that they end my seeking....at least for a good while.

http://www.audiokarma.org/forums/in...-psa-2-cleaning-and-return-to-service.555030/

If not mentioned in that thread or another one you read the ±15 volt supply on the PSA-2 is the critical adjustment per the Crown Tech at AE Techron a Crown service facility using many former Crown employees.

Ok I'll look into that!

If one of the other rails drifts too far, the amp fan will come on and the amp will subsequently make garbled noises and go into shutdown. I've adjusted mine a couple times, and these are the symptoms I've encountered.

When checking the voltage, you need to be careful not to short the adjacent pins. With the amp still off, I run three insulated, solid wires to the +, -, and neutral 15 volt pins (just stuff them into the plugs) so I can check these voltages outside of the amp without fear of shorting these pins. If to voltages are right on, great. If they have drifted, I turn the amp off and note the position of the wipers. I then move them back and forth to clean them and return them to their original positions. Then I turn on the amp and tweak them into position. You don't want to be far off when you power up. Also, one of mine was originally sitting at 15.05 volts (other had drifted down causing the noted problems) so I reduced them to 14.95 volts to contact a different spot on the wipers.

Threat the pots/wipers very carefully. They are no longer manufactured and made of unobtanium. Also, be careful of any glass diodes which are also made of unobtanium. I broke one for the LED display and a silicon diode does not respond the same (clipping light would come on too early). Luckily, I was able to get an original replacement from a Crown service dealer on the JBL forum.

I'm not sure what most of that means, but I can tell it's valuable information and I'll need to look in to all of that. I've never done any maintenance/adjustments on an amp/receiver aside from cleaning pots/internals with spray......I know I have a lot to learn.

Most likely they were disconnected when the other tweeter array (the ones you didn't get) were installed - just a guess.

Yeah I figure the same, but I'm just wondering why there doesn't seem to be anything to connect the tweeters to. I get disconnecting the tweeters, but I don't get removing that part of the crossover....but maybe they didn't, and I just don't understand what I'm looking at in there.

 

[toddalin]

Ok, the cap is 52uf and the resistor is 25 ohms.

OK, this is not for the tweeter circuit but to protect the 2440. See my post on adding a 1 mfd cap/L-pad for the tweeter and put this on the same wires that connect the 2440. Use a quality (not electrolytic) cap intended for crossovers.

 

[G871]

OK, this is not for the tweeter circuit but to protect the 2440. See my post on adding a 1 mfd cap/L-pad for the tweeter and put this on the same wires that connect the 2440. Use a quality (not electrolytic) cap intended for crossovers.

Ok great, I can do that.

Now, in the long term for optimal sound quality, a custom crossover designed specifically for the components involved would be even better, right? Thinking about acquiring an active crossover that would allow me to separate the tweeters, mids, and woofers to experiment with different crossover setups so that I can eventually build the best passive network I can, and then use my Sansui 1000a tube amp for the mids/highs and a PSA-2 for the lows. Cause the VFX2A only allows me to separate the tweeters/mids from the woofers, right? I couldn't run them all separately with it could I?

I know I've already said it, but thank you yet again. Huge help.

 

[G871]

I think I've discovered something.....

When I noticed what was written on the patch boards in back, I felt like that was evidence of something, but I didn't know what. I went looking for wires in the cab, and at the crossover, for numbers 1-4. I found nothing, until I was looking up 2405's on ebay and my search brought up a pair of crossovers listed for use with "075 076 2405 etc". They look like they would fit the patch panels on the back, and the holes in the cabinets they cover look to be original.....clean smooth cuts and same black finish as the rest of the back....but most importantly, they have the LF and HF inputs labeled 1, 2, 3, and 4, along with the red/black outputs, all just like it's written on the patch panels. They also have the same grey-sleeved wires as are connected to the mids and tweeters on these.

So, I'm convinced I'm missing a $500 (each) JBL N7000 crossover (or similar) in each of these 4 speakers......which I was kind of bummed about when I first realized it. But, I've learned that they're actually very simple, consisting of 2 caps, 2 inductors, and the potentiometer. So, I could easily build these....they work with the 2405 for sure (based on other people's experiences), but not sure about the 2440....anyone know?

 

[G871]

Maybe not just 4 parts - looks like 6:

Am I reading that right?

 

[toddalin]

Yes, they are basically that simple. But for the slot tweeters you want you use the N8000 or something in between. The difference is in the size of the chokes. The N8000 uses the same cap layout, but with 0.3 mH inductors. When I made mine, I was still using the 075s, but wanted it a bit higher and wanted to use 0.4 mH inductors. But Parts Express was out so I used 0.5 mH to raise it just a bit and subsequently changed the 075s for 2405s.

Nelson Pass of Pass Laboratories prefers the 2405/077 with just the single 1 mfd cap as I described above.

http://www.firstwatt.com/pdf/art_l300.pdf

BTW, $500 each for N7000s is WAY TOO MUCH!.

 

[drglasser]

Quick pics! They look smaller in the pictures than they do in person.

Those are Yamaha NS-690's in front.


View attachment 1330241 View attachment 1330242 View attachment 1330243

The veneer has minor imperfections but overall is in great shape to my eyes. I think once they're cleaned up they're really going to shine. Heavy layer of dust on everything...but not for long. Soon they will be sparkly clean and beautiful.

Have more stuff to go through and move out of my dad's house today when I get off work, but am hoping to grab cables between work and that so I can at least hook them up for a listen tonight.

It's so exciting to have these behemoths in my posession. I'd been wanting to try something huge like an old EV, Altec, etc but I get the feeling that these are probably going to surpass even those in sound quality.......

I'll have more pictures asap. The 2440's look to be installed cleanly with a additional piece of wood added to the back of the cabinets for the 2440's magnet to mount to or sit in......looks well done and painted black. Same with the front 2440 baffle - all looks well done. Hoping any internal modifications are of the same quality.

It seems that the amps where originally set up for use as mono amps. Two D75 amps for right and left channel tweeter. Two PSA amps for left and right woofers..
You will find a switch on the back of the amps to switch their modes into mono use.
Then no y-connectors are needed.
See my system picture in the gallery.
By the way flipping them into mono mode more than doubles the output power.

 

[bowtie427ss]

It seems that the amps where originally set up for use as mono amps. Two D75 amps for right and left channel tweeter.

There were additional tweeter arrays in the system, at least 2 clusters of 4 each 075/2402 bullet tweeters.They were likely powered by the D-75's.

Or, perhaps the 2405's were powered by one D-75 while the bullet arrays were powered by the other.

Maybe the OP can enlighten us by listing what he didn't buy/left behind.

 

[G871]

Ah, yes there were 2 clusters of 4 each 075/2402 bullet tweeters, and I do believe these would've been powered by the D75's, as they were labeled "ultra high frequency". (one PSA-2 unlabeled, the other labeled "very low frequencies.") The 2405's weren't connected while installed on the ceilings at all - I helped the seller and a couple helpers get them down with scaffolding and we unhooked them as we went. One pair had only the woofers connected by wires coming out the back patch panel (sloppy) and going into the ceiling. The other pair had the woofers and midranges connected, by way of the original binding posts. The woofers were connected directly to one pair of the original binding posts, and the midranges were connected to the other posts through a simple circuit with a cap and inductor....but I don't think it was originally intended for the 2440. I got a better look with a flashlight and the holes for the patch panels down in the back corners are not original to the speaker. The corners are not nearly as clean as the corners of the terminal panel cutout....but the shape definitely matches the JBL crossover shape. I think JBL crossovers were added at the time the mids and tweeter were changed to JBL, and then taken out at some point. Who knows why. And then someone in their past jerry rigged the woofers of one pair and the woofers and mids of another pair to play along with the subs and bullet tweeters on the ceiling.

There was a stack of crown stuff - I took all of that. The two PSA-2's, two D75's, and a VFX2A. In another stack on another table was 3 BGW amps - one a 750b, and then I think a 250(?) and another smaller number. I wanted to get the 750b, but didn't want to pony up the additional cash. Those weren't labeled.

There was also a LOT of other gear. A couple equalizers (one a Urei), a JBL frequency dividing network, and a bunch of stuff I wasn't familiar with. But that's it for amps, crossovers, etc. I think the stuff I wasn't familiar with was mostly DJ'ing stuff.

 

[gdmoore28]

Have you (OP) thought about using the suspension hardware on the speakers to suspend them from your own ceiling? I've done this* with a number of speakers and, once properly oriented, got the best mix of tone, directionality, and sound-staging than I've ever obtained from any other speakers.

* Not that I would do it with speakers that size and only 8-10 feet high ceilings!

GeeDeeEmm

 

[Dazaa]

I keep coming back to this thread expecting pictures of these speakers and everytime I leave disappointed

 

[G871]

Have you (OP) thought about using the suspension hardware on the speakers to suspend them from your own ceiling? I've done this* with a number of speakers and, once properly oriented, got the best mix of tone, directionality, and sound-staging than I've ever obtained from any other speakers.

* Not that I would do it with speakers that size and only 8-10 feet high ceilings!

GeeDeeEmm

Haha yeah that's my situation. Small living room with 7' 3" plaster ceiling. But, I will be keeping the brackets for sure.

I keep coming back to this thread expecting pictures of these speakers and everytime I leave disappointed

Pictures of the speakers are on page 5! Working on figuring out the best crossover to build and then I'll get them cleaned up and get better pictures, and more pictures. (of the insides, etc)

Yes, they are basically that simple. But for the slot tweeters you want you use the N8000 or something in between. The difference is in the size of the chokes. The N8000 uses the same cap layout, but with 0.3 mH inductors. When I made mine, I was still using the 075s, but wanted it a bit higher and wanted to use 0.4 mH inductors. But Parts Express was out so I used 0.5 mH to raise it just a bit and subsequently changed the 075s for 2405s.

Nelson Pass of Pass Laboratories prefers the 2405/077 with just the single 1 mfd cap as I described above.

http://www.firstwatt.com/pdf/art_l300.pdf

BTW, $500 each for N7000s is WAY TOO MUCH!.

I totally agree on the price. That's just what I see them for on ebay......but you know how that goes. I was bummed until I realized they'd be very easy to recreate. And after doing a bunch of research the past few days and finding other posts of yours toddalin, I see you have some valuable experience messing around with these sort of crossovers.

I have a new development and I'm curious how you think this will affect what would be the optimum crossover for this situation. (and anyone else who wants to chime in, too of course)

The 2440's have 2441 diaphragms, and I believe they are titanium judging from the color/sheen.



I've been doing as much research as possible the past few days, and learned that the 2441 diaphragms allow the driver to reach much higher than the 2440 diaphragms do. One person claimed 15khz - do you know if that is correct? How does this affect the crossover I need to build?

I also discovered that the 2390 (2309 horn/2310 lense combo) is intended to be used from 800hz and up. (from official JBL literature)

So I suppose the woofers will be ran up to 800hz, 2441's from 800hz to somewhere around 10-15khz(?), and 2405's from there on up. Is that what you'd recommend? And if so, do you know how I would achieve this? Would the N8000 network still work as you suggested earlier? Maybe with further modification similar to something you mentioned somewhere along the way, to get the tweeter to come in even higher than 8khz?

 

[toddalin]

Titanium does go higher. You may be fine with it and want to use the tweeters elsewhere. Alternatively, some don't care for the titanium highs and you may want to cross them over anyway.

Many of the early JBLs used that horn/lens/driver arrangement to 500 Hz in the home systems (e.g., Hartsfield). Higher frequencies are suggested in the professional environment where power levels are higher for more sustained periods that can damage/fatigue the diaphragms.

Also, because you have an electronic crossover, the slope would in all probably be steeper than on a passive crossover allowing you to safely play a bit lower. As I said, find what works best in your room, but try to keep it to no lower than 500 Hz, and never play it below 350 Hz. The 2440 diaphragms may have played a bit lower being a bit heavier.

Yes, the N8000 will work for your situation, especially with the 2441 diaphragms.

Be sure to replace that foam.

 

[G871]

Wonderful information. I'll definitely get that foam replaced as I clean these babies up.

So....I feel like you may have already answered this, but sometimes it's difficult for me to decipher talk about crossovers....easier for me to see it in a schematic....but, if I wanted to bump the crossover frequency from the mid to the tweeter up even a bit higher than 8khz, like say 10khz, how would I modify the N8000 to do that? Is that a wise thing to do?

Edit: Now that I've found a frequency response graph comparing the 2440 and 2441, I'm thinking I don't want to raise the crossover point. While the 2441 does have output much higher than the 2440, it drops off steadily after 6khz. So I guess nevermind that question.

 

[toddalin]

When I told you to change the foams, I subsequently realized that I was setting you up for failure! There is something VERY IMPORTANT that you need to know before doing this.

The two "horseshoe" and two round clips held by the screws are FERROUS! As soon as these screws are loosened and the wires pulled, those clips (screws too if you take them out) are going to want to be attracted to that massive magnet and will stick to the diaphragm faster than you can say "OH SH-T!!!" (BTDT as have a myriad of other people.) When this happens it will leave dents in the diaphragm. If you ever see a pic of a diaphragm and you see two dimples next to each other..., you get the picture.