C-Note excursion

[JoeC]

Thanks for the reply Kornbread.

Curious as to why PE would not warranty a woofer because of an aftermarket crossover? From the pics, it looks like all Dayton parts, and after all, this is diy where many of us build our own crossovers from scratch.

Unibox says tuning is 40hz using a 7.5"x1.38" port, in a .31ft³/8.8L box. Seems a bit low, but let's roll with it.
Anyhow, @27watts, yeah, if you like listening to edm, I could see a problem.

I have no idea as to why I would not get warranty for using a third party board... but that was the first thing they stated. This C-Note is a diy kit, and all the parts were provided from P.E. except that XO board/glue and the wood grain cover/black paint. PE told me I must have wired the caps wrong but I used this for 2 and 1/2 months before I ran into issues. I have not changed the XO's except removing the green connectors and adding a .22 cap. and didn't do that until I got some distortion on the left side.

if you like listening to edm

I'm a bit of a noob and I have no idea what edm is
This is the board before I put it together...

[fpitas]

Thanks for the reply Kornbread.

I have no idea as to why I would not get warranty for using a third party board... but that was the first thing they stated. This C-Note is a diy kit, and all the parts were provided from P.E. except that XO board/glue and the wood grain cover/black paint. PE told me I must have wired the caps wrong but I used this for 2 and 1/2 months before I ran into issues. I have not changed the XO's except removing the green connectors and adding a .22 cap. and didn't do that until I got some distortion on the left side.

I'm a bit of a noob and I have no idea what edm is

Electronic Dance Music. Lots of powerful bass below what real instruments normally produce.

[JoeC]

I'm mostly classic rock and jazz. Not into edm

[LOUT]

Yes... my receiver does have a button labled "Loudness" and another one called "Subsonic Filter". Of course I have the loudness on and the sub filter off

I think you can just use "loudness" to taste (usually I think it's used when playing at lower volume and off when playing loud).

I believe turning the Sub-filter ON should protect the woofer from some very low/deep frequencies, which should help protect it from over-excursion. Anyone else know if I'm misinterpreting this?

[Kornbread]

I think you can just use "loudness" to taste (usually I think it's used when playing at lower volume and off when playing loud).

I believe turning the Sub-filter ON should protect the woofer from some very low/deep frequencies, which should help protect it from over-excursion. Anyone else know if I'm misinterpreting this?

Sounds about right to me. Some of the old Carver, and pro amps I have around, have a subsonic filter. IIRC, the Behringer begins to cut under 50hz with the Carver around 20hz. More than likely, the loudness button boosts the bass/mid bass area.

Have a diagram of the c-note crossover and one of the board to compare? That's odd.

[JoeC]

diagram of the C-Note cross over is Here:
https://www.parts-express.com/pedocs...y-response.pdf
All I can come up with for the board is the ebay link from where I got it from

https://www.ebay.com/itm/283522006203

Do you think getting a more powerful receiver will prevent these speakers from excessive excursions?

[Wolf]

1- shut off the loudness.
You are boosting the low end with this on. Some receivers have this as +10dB with a broad Q, meaning the amplifier is likely clipping at louder volumes with the switch engaged. I know it seems counterintuitive, but more bass is not always what it seems. +10dB is perceivably twice as loud, and also ~9x the power requirement to maintain it. Every +3dB = twice the power. Since this is not even 100W, you are definitely clipping the amp at moderate levels. Loudness is meant for softer output levels.

Secondary info, loudness also boosts the 10kHz region in most cases, and you are likely hearing this as improved clarity.

2- turn on the sub/infrasonic filter.
This will stop the power starving to a degree and keep both the amp and speaker happy. If you insist on leaving this off, see #3.

3- I'm betting you have some sort of DC offset problem in the amp, or the suspension would not do as it has done. If the woofers suck in or push out without signal applied when the amp turns on, even with #2 applied, you either need a new or repaired amp.

Best regards,
Wolf

[Kornbread]

1

3- I'm betting you have some sort of DC offset problem in the amp, or the suspension would not do as it has done. If the woofers suck in or push out without signal applied when the amp turns on, even with #2 applied, you either need a new or repaired amp.

Best regards,
Wolf

Since it sounds like he has a multi-meter, cannot he measure dc offset at the amp's output?

[Wolf]

I'm not savvy on the details to recommend how, but likely yes.
Wolf

[JoeC]

Since it sounds like he has a multi-meter, cannot he measure dc offset at the amp's output?

How would I go about doing that, and what numbers should I expect to see?

To make my point a little clearer, I did have the loudness off and the subsonic filter on, The speakers only push in and out while I'm playing music...especially something with bass like Pink Floyd. Of course this is after the fact that they have already failed. I'm looking at the option that the only way I can hear it nicely I'll have to keep the volume down low and keep an eye on the speakers for any excursion. If I turn off the loudness and have the subsonic filter on....well that sounds like a 1966 tiny hand held transistor radio I had when I was a kid

Edit: Getting kinda late now so I'm going to do this tomorrow...

https://www.wikihow.com/Measure-DC-Offset

[Kornbread]

How would I go about doing that, and what numbers should I expect to see?

If I turn off the loudness and have the subsonic filter on....well that sounds like a 1966 tiny hand held transistor radio I had when I was a kid

Edit: Getting kinda late now so I'm going to do this tomorrow...
https://www.wikihow.com/Measure-DC-Offset

Search youtube for 'measuring dc offset amplifier' and you will get multiple hits. Easy Peasy.

Just to reiterate, I have not heard these speakers, but they shouldn't sound like a tiny hand held transistor radio without both the loudness and infra buttons on. Something is wrong, either the amp, crossover, wiring, something.

... I only see four caps on the ebay board add copy and your pic of the crossover. Where did you place the .22uf cap?

[JoeC]

Post # 14 and post #16. I did not get a pic of the board after I removed the green connectors for the speaker wires or the .22 mfd cap, but on the board itself it is listed as N/C. (post #16) Here is a review and more specs about these speakers...

https://www.audiosciencereview.com/forum/index.php?threads/parts-express-diy-c-note-speaker-review.12693/

There was a 3K break up in the woofer and the .22 cap was recommended between the power in and air coil. This is a very detailed review and the designer from PE named Chris P made comments about this speaker in the thread.

[Chris Roemer]

Are you POSITIVE that your woofers are "in phase"?
The 1st pic of your XO concerned me that (on the lower left corner?) one cap lead (left end) is VERY close to the adjacent coil. The coil wire's insulation SHOULD protect the situation from a short there, but EYE would definitely bend the cap lead away from the coil (1/8th inch MINimum) so you can see air between them. A bare cap lead, resting on a varnished coil wire (and vibrating) COULD wear through that clear (varnish) coating on the coil, causing a short - after a while.

[JoeC]

Those pics were taken before I soldered the caps, resistors and coil. If it is close... and I do recall it was a very tight fit around one of the coils if I can I'll see if I can open up that area if it is in contact with the coil. At worse I think I can sandwich some thick plastic between the cap and coil. Something like the clamshell plastic you see in some packaging. Later today I'll have to get in there to check it out better, and want to check the dc offset too.

[Kornbread]

In the first post you state you like the way they sound. Was this with the loudness button on? During that time, w/o the loudness button on, did it sound like a cheap tiny transistor radio, or does this comment only apply to after the woofers began giving problems?

Guys, I am not good with flipping stuff over in my head. Looking at the add copy of the ebay board, NC, the place the .22uf cap is supposed to be placed, where are its connection points?