Nord User Forum

I just joined due to all the CPS users here and I figured y’all could help me out.

I’m getting a resonant rattle around 200hz from my CPS. The rattle sounds like it is coming from behind the main driver. The first cab had it at on F3 and it’s replacement cab has it on Ab3. All other notes are clear and sounds great, no constant hum or buzz but hit that note and rattles abound. Has anyone run into this issue?

I’ve tried different cables ( asterope and planet wave) different power sources (home and rehearsal hall), IEC cables, Furman power conditioner. It’s just strange to me that two cabs have it. I’m a guitar player so the rig is a helix into it the CPS. The helix into a k8.2 is clean and clear. I’ve gone through different patches of darker and brighter tones, but the rattle doesn’t go away.

Tomorrow I’m going to try the CPS with a keyboard and see if I have the same issue. What else should I try?

I called Pittman and they talked about the typical issues (good cables, hum eliminator, power source) They also offered to replace it but I want to run down all the possibilities on my side before I do that.

Thanks all!

I wonder if the speaker is well attached, can you open it and check if all screws are tightened?
If the speaker itself rattles, there is not much you can do other than replacing the speaker if you think it might be faulty, but if they all do it, then it sounds like a design fault. Or perhaps use an equaliser to attenuate that particular frequency?
I am not sure there are many CPS users here, I have the feeling that at the Keyboard Corner Forum there are quite a few more. It might be worth asking there, too.

I went through the screws on the outside, the all are good. I thought about pulling the speaker out and checking the inside but I don’t want to void a return policy. Good idea on the frequency attenuation, used a parametric at the trouble frequency, it lessens it to some degree but it’s still there.

I’d read a bunch of posts from @cphollis from here which is why I joined up. Hoping he will answer since he seems to have quite a bit of experience with he CPS.

Thanks for the reply Mr G

Ah, yes, you are right, cphollis reported to have one.

nodnarb0007, I suggest you contact August Pittman, the daughter of Aspen Pittman, and, president of Aspen Pittman Designs, the home of CPS. You can find her on Facebook. There is also the Center Point Stereo Family group on facebook, with about 300 members. Even if you don't normally use Facebook, you could set up an account just for those contacts. Also you can contact the company through a message interface on their website at https://centerpointstereo.com. I suspect there is something loose in the amp, either a loose fastener or something that's come unglued or broken/unattached. I don't have a copy of my Spacestation XL's warranty handy, but I seriously doubt that August would not honor the warranty if you opened up the amp and looked for damage. I took the amp out of my amp to make sure the I wouldn't damage anything by adding a handle to the top, and I opened up the speaker cabinet when I added a set of corner casters. I was very, very pleased with the overall mechanical design and build quality; everything was strongly built and well attached. Here is a shot of my Spacestation on stage, sitting on top of the Leslie 3300.

200 Hz vibration? First suspect would be adjacent loose hardware: stands, bolts, etc. Yes, it's small, but it's ballsy and it can shake stuff nearby. 200 Hz is right in the sweet spot where that happens. I have had the same sort of problem with other small speaker units that put out a lot of power: K8s, RCFs, etc. Not specific to CPS V.3.

Don't take it apart yet, try that first. I've taken them apart a few times, easy enough, robust construction. Not much that could get loose in there, but you never know.

Nice to hear that Aspen's daughter is still with the business. He was a really interesting guy. The amp is pretty interesting as well.

Also, the other place where CPS users hang out is on the Keyboard Corner forum. When the CPS was announced, there was the mother of all threads there that went on for years. I bet it's still there.