N1200 polarity Question.

[rocks66ss]

I was wondering if I have these correct

LF 1 pos
LF 2 neg
HF 3 neg
HF 4 pos

looking at a schmatic online I believe this is correct. I just need confirmation.

Thanks

Rocky

[Mr. Widget]

Yes, you are correct regarding red and black terminals... as to positive and negative?
JBL was bassackwards back then, so that is anyone's guess.


Widget

[rocks66ss]

Yes, you are correct regarding red and black terminals... as to positive and negative?
JBL was bassackwards back then, so that is anyone's guess.


Widget

I kind of surprised. 98 people have view and one adminastrator has commented. and no one is sure of what I ask.


Rocky

[Riley Casey]

Yes that is what the schematic reads. As to if that is correct in terms of any given speaker system will depend on the drivers in use and the enclosure design. Always best to determine connection polarity empirically unless you are using the crossover exactly as intended by JBL.

I kind of surprised. 98 people have view and one adminastrator has commented. and no one is sure of what I ask.


Rocky

[Mr. Widget]

I kind of surprised. 98 people have view and one adminastrator has commented. and no one is sure of what I ask.


Rocky

Hi Rocky,

I guess my answer was too cryptic. What I was trying to say was that, yes, you are reading the schematic correctly for a N1200 crossover. Additionally I was attempting to point out that when this network was created, JBL's standard for polarity was the reverse of the rest of the industry.

The N1200 was designed to work with one of three woofers and one of two tweeters.

Woofers: D130, D131, or 130A
Tweeters: LE175, or LE85

If you use any other drivers, your results will likely not be what you are hoping for and at this point, it is anyone's guess how your speakers will turn out as many of these vintage drivers have been altered and there is no guarantee that you will achieve the desired results. That said, feel free to experiment.


Widget

[jbl4ever]

Use to be on this site but can not find it in the Library anymore. Google search JBL crossover connections. Look for the site www.cieri.net JBL dividing network instruction manual. It is 8 pgs of crossover info and hook ups. And Widget is right

[Odd]

[rocks66ss]

Hi Rocky,

I guess my answer was too cryptic. What I was trying to say was that, yes, you are reading the schematic correctly for a N1200 crossover. Additionally I was attempting to point out that when this network was created, JBL's standard for polarity was the reverse of the rest of the industry.

The N1200 was designed to work with one of three woofers and one of two tweeters.

Woofers: D130, D131, or 130A
Tweeters: LE175, or LE85

If you use any other drivers, your results will likely not be what you are hoping for and at this point, it is anyone's guess how your speakers will turn out as many of these vintage drivers have been altered and there is no guarantee that you will achieve the desired results. That said, feel free to experiment.

Widget

I built my speakers in the mid 80's actually built from plans for the 5qf boxs found on this site. I use a D130 and LE175 patato masher. I haven't been sure if I had them hooked up correctly until tonight when I read this answer. I found the schematics and was reasonably sure but not 100% I am redoing the insulation in the cabs, when I took the speakers out, Slice Speaker in Kansas City, had reconed my D130's in 97. I have a spare N1200 and I am going to recap it and see how it sounds to one that hasn't been. getting them out of the box looks like a challenge. Any tips on getting them out of that muck, wax, whatever it is.

Thank you for the response.

Rocky Hill

[Mr. Widget]

Would you consider bi-amping your speakers?

If they were mine and I hoped to improve their sound, that’s what I would do. A pair of small amps and a nice new DSP active crossover and you are off to the races.

Alternatively, I would keep them as is. Someone else might invest the time to dig out the networks and recap… plenty have made the investment in time and effort. There are threads here that explain the process.


Widget

[rocks66ss]

Would you consider bi-amping your speakers?

If they were mine and I hoped to improve their sound, that’s what I would do. A pair of small amps and a nice new DSP active crossover and you are off to the races.

Alternatively, I would keep them as is. Someone else might invest the time to dig out the networks and recap… plenty have made the investment in time and effort. There are threads here that explain the process.


Widget

At this time I don't want to invest in more amps, I have too much going on in my life, maybe a year from now i might consider bi-amping. Question, I really hadn't give much thought to a DSP active crossover until now. I was looking at them on line. Do you think those would be the best bet to inproving the sound over the N1200's? To be honest, over the years I really havent been exactly thrilled with these crossovers.



Rocky

[Mr. Widget]

At this time I don't want to invest in more amps, I have too much going on in my life, maybe a year from now i might consider bi-amping. Question, I really hadn't give much thought to a DSP active crossover until now. I was looking at them on line. Do you think those would be the best bet to inproving the sound over the N1200's? To be honest, over the years I really havent been exactly thrilled with these crossovers.

Agreed, but they have gotten much better. Considering the limitations of your loudspeaker components, (frequency linearity and bandwidth) I think a well implemented DSP/crossover will keep the benefits of these speakers (dynamics and "life like" sound) and reduce most of their limitations.


Widget

[rocks66ss]

Agreed, but they have gotten much better. Considering the limitations of your loudspeaker components, (frequency linearity and bandwidth) I think a well implemented DSP/crossover will keep the benefits of these speakers (dynamics and "life like" sound) and reduce most of their limitations.


Widget

You will have to excuse my ignorance, as I am still using a Toshiba SA-620 receiver I purchased in 1978 and haven't exactly kept up with modern technology lol. I have looked online for the DSP/crossovers, and I noticed some are adjustable, and some are not. Do you recomend a type or brand i should look for?

Thank You For your help!

Rocky

[Mr. Widget]

Nothing wrong with a ‘70s receiver, but it probably doesn’t have preamp outs and amp inputs making adding an external processor rather difficult. I think going down the road I suggested, is likely not a good fit.

Following my earlier suggestion will require a significant investment in time to tackle the learning curve and likely a greater financial outlay than you would like to make. In addition to adding a basic stereo amp and DSP crossover, you would probably need to replace your receiver with a preamp and another power amp... and a tuner if you still use the FM section.



Widget

[rocks66ss]

Nothing wrong with a ‘70s receiver, but it probably doesn’t have preamp outs and amp inputs making adding an external processor rather difficult. I think going down the road I suggested, is likely not a good fit.

Following my earlier suggestion will require a significant investment in time to tackle the learning curve and likely a greater financial outlay than you would like to make. In addition to adding a basic stereo amp and DSP crossover, you would probably need to replace your receiver with a preamp and another power amp... and a tuner if you still use the FM section.



Widget

Actually I can uncouple my pre amp from the amp on this paticular model. is this a help in the situtation we are talking about? And as far as using the FM side I have a digital interface from my computer , phone or what ever uses bluetooth


Rocky

[Mr. Widget]

Actually I can uncouple my pre amp from the amp on this paticular model. is this a help in the situtation we are talking about? And as far as using the FM side I have a digital interface from my computer , phone or what ever uses bluetooth

That certainly makes it economically less painful. You simply insert the active crossover between the preamp portion of your Toshiba and its amp. You’ll need a second amp, a high quality 50wpc stereo amp is likely all you need. (Any quality stereo 25wpc to 100wpc should fit the bill.)


I use an Ashly Protea 3.6sp in my system… it is a powerful and very versatile DSP. It is probably not the best choice for someone just starting out and jumping into the multi-amp end of the pool. I would suggest starting a thread here focused on DSP crossovers asking others for their input. I have been in the deep end of the pool for so long, I really don’t know what others use that are user friendly and would more easily get you going.


Widget