Help! My SVS 20-39cs has stopped working. (1 Viewer)

[Zac_F]

My 20-39 cs has stopped making any sounds. I checked the cabling, the sub amp, the receiver, all by unplugging the speaker cable from the SVS and plugging it into the woofer input of my bi-wireable main speaker. When I did that my main worked as expected with a test tone. Swapping directly back to the SVS got me nothing.

Is there an internal fuse of any kind on the SVS? If I had blown the driver, i would think it would make some awful sound, not just silence. I'm willing to open it up if I have to, I built the mains that I'm using and am not shy about diving in.

Other useful info: My receiver is an Outlaw 1050, my sub amp is a Part Express 250w plate amp in a box. I'm using the LFE out from the receiver to the sub amp, then the sub amp output wires are connected to a speaker cable with quick disconnects.

It was working last night when the kids were watching a movie, and while it was somewhat loud, it wasn't nearly as loud as I've had it before.
I bought it used (the seller had upgraded to another SVS) and it is not under warranty, but if the SVS guys have any advice I'd appreciate it.

TIA

Zac

 

[Edward J M]

Zac:

I would immediately e-mail SVS technical support at:

[email protected]

I'm certain they will get back to you shortly with directions on what to do next. They read their email quicker than they catch up on the various forums.

It sounds as if your trouble shooting was logical - especially if connecting the leads to another speaker provided a test tone sound. That pretty much eliminates the electronics end of things.

I would say at this point you have an internal problem: A disconnected wire, a broken tinsel lead, or an outright blown driver.

Question: Does gently pushing on the driver cone generate a grinding or grating sensation, or does it move smoothly back and forth?

Question: Is this an original CS driver, or an Improved Standard Driver (shipping since mid-December 2001)?

Question: What is your method of sub calibration (disc, test tones, SPL meter)?

Question: How "hot" are you running your sub on the calibration as compared to the other speakers?

Regards,

Ed

 

[Zac_F]

Question: Does gently pushing on the driver cone generate a grinding or grating sensation, or does it move smoothly back and forth?

-Pushing at the driver is smooth as silk.

Question: Is this an original CS driver, or an Improved Standard Driver (shipping since mid-December 2001)?

-This is the improved driver. The date on the box is January 2002.

Question: What is your method of sub calibration (disc, test tones, SPL meter)?

-I used the receivers test tones and the Avia test tones, with the rat shack spl meter.

Question: How "hot" are you running your sub on the calibration as compared to the other speakers?

-I calibrated the sub when I got the PE amp a few months ago to about -3db from the mains using the receiver test tones. I didn't pull out the Avia disk, which experience has shown gives me a reading about 3db down from the receiver. I'm never sure which one to believe. My ears tell me the -3db is even too high. My wife of course tells me its all too loud.

I guess I'll contact SVS directly. I've only heard good things about their support.

 

[John F. Palacio]

Is there an internal fuse of any kind on the SVS? If I had blown the driver, i would think it would make some awful sound, not just silence. I'm willing to open it up if I have to, I built the mains that I'm using and am not shy about diving in.

No fuses on SVS's passive subs. Do you own a VOM (Volt-ohm meter)? If so measure the DC resistance at the subs's terminals.

It should be around 2 ohms or so. If you measure infinity, there's something open (disconnected inside wiring or potentially an open voice coil) If it's close to 0 ohms you have a short and it is almost surely a shorted voice coil.

Good luck.

 

[Zac_F]

Hmm. It read 3.4 ohms. So I don't have an open circuit, nor do I have a short.

 

[Edward J M]

-I calibrated the sub when I got the PE amp a few months ago to about -3db from the mains using the receiver test tones. I didn't pull out the Avia disk, which experience has shown gives me a reading about 3db down from the receiver. I'm never sure which one to believe. My ears tell me the -3db is even too high. My wife of course tells me its all too loud.

I'm not sure I understand this calibration description.

You are supposed to run the AVR's test tones and obtain 75 dB on C-Weighted Slow for each speaker and the sub at the key listening position by adjusting the individual speaker levels on the AVR, and the sub plate amp control as needed.

With the AVIA disc, it should be 85 dB instead of 75 dB since the AVIA disc is mastered 10 dB louder than the typical internal AVR test tones.

Question: Does your AVR automatically default to 00 on the Master Volume control when you activate the internal test tones?

Also - John's advice is excellent - if the cone moves smoothly, you probably have a broken tinsel lead, a disconnected wire, or a burnt VC. The ohm meter will narrow it down a bit.

 

[John F. Palacio]

Hmm. It read 3.4 ohms. So I don't have an open circuit, nor do I have a short.

That sounds about right.
Now then: Get a hold of a 1.5 v battery (like a D, C or AA) and with the help of wires connect one terminal (doesn't matter which) to the + of the sub and "scrape" the other terminal to the - of the sub.

You should hear a "thump".

 

[Zac_F]

I don't know what did it, but its working now. Dowsn't sound like I did any damage either, but I'm not stressing it yet.

I must have had a bad connection, but I was able to get my main to respond to the signal without problem, and when I reconnected the sub I couldn't. Go figure.

On the calibration question, I've always gotten different results between my AVR test signals and the AVIA disc. The Avia always has me lower the sub output by about 3db from what I calibrate using the AVR test tones. The AVR does not read 00 at 75db. I tend to believe the Avia, as my ears tell me the bass is "right".

Now that I have it working again, I'm going to re-calibrate the whole system since I messed up every setting getting it to work.

Thanks everyone for the advice.

Zac