BillFitzmaurice.info

After a previous post I decided on building a couple of J15's for my Wifes Aqua Zumba. It took me about 3 weeks working after work and a few Saturdays to get the first one complete - no paint.

She was very impressed with how loud and clear it was, especially since she was comparing it to running 2 TLAH's and 2 other HT tower Speakers. The single J15 was louder than the 4 combined and it was at 1/2 power on the gain of the M85 Yamaha amp.

Here is the Link to the first J15 Build: https://flic.kr/s/aHsm2x4vNo


Second build was much faster and easier. Especially the horn section, there are lots of small parts to cut.

Here are the pics of my second J15 build: https://flic.kr/s/aHskX46YBW .

I still need to paint the first one and build a small box to house the Mixer, DBX PA and Amp.

BTW Dutatex is my new favorite paint.

Great job, Oscar!

Very cool, not too many J15's with CD horns. Very nice!

Nice build!

Thanks guys,

Now to finish up amp rack, and finish up my curved SLA center channel. Then I hope to build some subs. First THTLP for HT or Or subs to pair with J15's. What subs best match up with J15's? T30/45 or Titans?

I mainly DJ for church dances and member weddings. Venue is a full court gym with no bleachers. Content is mainly recorded top 40, country, reggeton, and Spanish/Latin music.

I used a pair of delta 12LFA T30's I built for my bro in law. They did ok, but they were lacking. I think loading with premium drivers would help. Thoughts and comments appreciated

Houston we have a problem.

I took out both Jacks for a cruise today. Wife has a Aqua Zumba class at a public pool and she asked if I would help her take the system to the venue. I agreed. We got there, setup and started to adjust the sound as she was giving her class. As I turned up the volume I noticed the last speaker I build was cutting out. She had used it on Wed and had not complained so I thought it was odd. At first I thought it was a loose wire so I wiggled the wires on the CD to see if I could get itvti cut off and on, but it was still intermittent and not consistent. So I unplugged it and just used 1 Jack for the rest of the class.


When I got home I opened it up and found a couple if issues. One of my solders on the CD crossover was loose. one of the coils had come off. On the woffer xover, the positive lead to the speaker , I didn't tin the wire well enough and the connection was weak. I repaired both connections and tested. It worked much better, but when I turned it up, it still cut out, but I noticed that the amp signal would turn red like if it had a short. On the iNuke 3000 there is a light that glows around the gain knob. When the signal cuts out the. The orange glow turns to red. I tried both channels and the same thing happens.

Any thought on what may be causing this issue?

y2kindyz wrote:Houston we have a problem.

I took out both Jacks for a cruise today. Wife has a Aqua Zumba class at a public pool and she asked if I would help her take the system to the venue. I agreed. We got there, setup and started to adjust the sound as she was giving her class. As I turned up the volume I noticed the last speaker I build was cutting out. She had used it on Wed and had not complained so I thought it was odd. At first I thought it was a loose wire so I wiggled the wires on the CD to see if I could get itvti cut off and on, but it was still intermittent and not consistent. So I unplugged it and just used 1 Jack for the rest of the class.


When I got home I opened it up and found a couple if issues. One of my solders on the CD crossover was loose. one of the coils had come off. On the woffer xover, the positive lead to the speaker , I didn't tin the wire well enough and the connection was weak. I repaired both connections and tested. It worked much better, but when I turned it up, it still cut out, but I noticed that the amp signal would turn red like if it had a short. On the iNuke 3000 there is a light that glows around the gain knob. When the signal cuts out the. The orange glow turns to red. I tried both channels and the same thing happens.

Any thought on what may be causing this issue?

You most likely fried a diaphragm in the horn. A short will cause the amp to go into protect mode. Been there, done that. And yes the problems in the crossover will cause that.

Bruce Weldy wrote:
You most likely fried a diaphragm in the horn. A short will cause the amp to go into protect mode. Been there, done that. And yes the problems in the crossover will cause that.

Thanks for the reply Bruce. I removed the CD's and checked the Ohms. Both read 6.8 ohms. I opened them up to inspect the diaphragms and they looked fine. Is it still possible that one is bad with no visible damage? I didn't check the woofer. Could that cause the same issue?

When it plays it sounds fine up until it the amp goes into protect mode.

Do you think it could be one of the xover caps?

y2kindyz wrote:Do you think it could be one of the xover caps?

Open up the offending OT15, and take some clear photos of the cross-over, the back of the jack-plates, and all the wiring and connections. Post them on here or host them, in high resolution, on a hosting site and link to them.

FTR, if you were going to build subs, you should not have built OT15s, you should have built OT12s, DR200/250 or SLA Pro. Also, why did you go CD instead of the melded array? The melded array gives way better dispersion and off-axis response.

y2kindyz wrote:Do you think it could be one of the xover caps?

Certainly could. That's what blew mine.

Have you tried another amp?

Also, I recently had a horn go bad in one of my monitors. Took the diaphragm out and couldn't find anything wrong by looking at it. Fortunately, I keep spares, so I put in a new one and it worked fine.

While I'm telling stories.....a monitor from the band I work with started sounding really bad. The nastiness was coming from the woofer. The company is no longer in business as far as I could tell, so I bought a replacement speaker....put it in....exact same thing. Now I knew it had to be the crossover. Nothing visually wrong, so after a little research, I bought a crossover from Eminence that was as close to the old one as I could get. Speaker worked great.

Of course, now I have a spare 15" woofer. Fortunately, it's the same ones that I use in my monitors - so it's now in the spare bin with all the other 2512s, 3012lfs, and diaphragms for all my BFM boxes.

If anyone is using their gear on a regular basis and can't take a chance of being down for a couple of weeks - bite the bullet and have at least one spare of every driver and diaphragm that you use.

Thank you Bruce,
Hope you had a great fathers day.

I have not tried another amp, but the amp only clips with one of the Jacks. Other channel keeps playing. When testing xover componants, will the caps be the only parts to check or could the inductors cause problems as well?

y2kindyz wrote:Thank you Bruce,
Hope you had a great fathers day.

I have not tried another amp, but the amp only clips with one of the Jacks. Other channel keeps playing. When testing xover componants, will the caps be the only parts to check or could the inductors cause problems as well?

First - just to be sure.....try the bad Jack on the good channel....if it does the same thing on that channel, the you know it's the cab.

Most likely a cap. When mine went, it was quite evident...the end was blown out of it.

If nothing looks bad, then connect the CD directly to the amp - bypassing the crossover, then running a test tone (2-4k) and slowly bring up the volume....see how it reacts. Do the same with the woofer (100hz). You'll have now tested every component separately. If the driver and CD check out ok, then it's the crossover.

One caveat though, you could have blown a cap and a diaphragm. And that's why it's good to keep a spare available.

Bruce Weldy wrote:

y2kindyz wrote:Thank you Bruce,
Hope you had a great fathers day.

I have not tried another amp, but the amp only clips with one of the Jacks. Other channel keeps playing. When testing xover componants, will the caps be the only parts to check or could the inductors cause problems as well?

First - just to be sure.....try the bad Jack on the good channel....if it does the same thing on that channel, the you know it's the cab.

Most likely a cap. When mine went, it was quite evident...the end was blown out of it.

If nothing looks bad, then connect the CD directly to the amp - bypassing the crossover, then running a test tone (2-4k) and slowly bring up the volume....see how it reacts. Do the same with the woofer (100hz). You'll have now tested every component separately. If the driver and CD check out ok, then it's the crossover.

One caveat though, you could have blown a cap and a diaphragm. And that's why it's good to keep a spare available.

Ok I think I figured it out. Test 1 hooked up amp to speaker. Ran 100hz tone, turned up the volume to about 20 volts no clip. Changed tone to 3500 Hz turned up volume. No clip. Decide to run music thru it and it started clipping. Disconnected woofer xover. Turned up , no clip. Swapped to woofer thru the xover, disconnect the woofer and turned up the volume with music and hello clip.

So I am assuming the cap on the xover is the culprit. Is it possible the the inductor is the problem? How can I test the cap?

Thanks in advance,

It was evident when I blew a cap - the end was distorted and pushed out. Do you see any physical damage at all?

Can you take some pictures of the crossover? Closeups of the components would be good. Maybe someone can see a flaw somewhere.