Subwoofer problem-Kinda long-newbie questions (1 Viewer)

[John I C]

Great to find this forum! A lot of y'all really know your stuff! Hopefully you can give me some assistance.

I recently purchased a Panasonic SA-XR25 A/V receiver. Prior to this receiver I had a Sony Pro-logic receiver. All is well with the new receiver, but I'm having a problem with my subwoofer's dropping to standby whenever there are no loud sub sounds eg. during dialogue. When it does come back on, many times the sound effect is half over. In other words, it seems like there has to be a fairly high level of signal before the subwoofer will "pop" on.

I have a Sherwood subwoofer, which was connected to my Sony via speaker level inputs. When I got my new receiver, I connected the sub to it via the RCA jack labelled "sub" on the back of the receiver. Now, the sub has only speaker level or line level connections. It does NOT have an LFE connection, just left and right line level.

The Panasonic receiver manual states to use a mono connection to the sub. So I used an RCA cable from the receiver sub out to left in on the subwoofer. When I experienced the problem, I went to Radio Shack and bought a $15 gold-tip "Y" cable specifically for subwoofers. Still the same problem. Sub sounds great for the loud sequences, but shuts off during lower volume parts.

I have the speakers set to "small" in the Panasonic, sub is "yes", and the crossover is as high as it goes (200) I've tried messing with the dynamics settings on both the DVD and the Panasonic receiver. Nothing really helps...And there doesn't seem to be any control on the sub to leave it "always on" or "auto on". And I never had this trouble when I connected to my old receiver via speaker level. One more thing- when I use an analog source in the receiver (like my vcr)the sub works fine.

I'm new to owning a digital receiver, but I suspect that the level of signal provided by the LFE output is not enough to keep the sub on all the time. In my old pro-logic setup, it was getting speaker level, and stayed on. If I use a stereo analog source, it stays on. But if I use DD 5.1 or DTS, it will drop out.

SO...Can the sub out from the receiver provide enough signal to the line inputs on the sub? Is a "subwoofer" cable any different from another high quality shielded RCA cable? Should I "y" the cable or just use left? Is there some kind of small external amp I can stick on the cable to boost signal? Is that even the problem?

Thanks for reading all this, and thanks in advance for any suggestions you might have!

JC

 

[Rory Buszka]

The Sherwood is probably not a very good sub. You could do much better for not much money. You might try setting the subwoofer's level a little lower and then using a higher level at the reciever.

 

[John I C]

I've tried everything I can to get the sub to come on and stay on. I've purchased and returned two different cheapie amplifiers- one from Circuit City meant for phono signals, and one distribution amp from Radio Shack designed to amplify many sources to many outputs.

Neither worked, but I still think it's just a a matter of getting MORE LFE signal to it, to "fool" the circuits into staying on.

I see that Partsexpress.com has a sub plate amp on sale for $65. Could this help me? I'm thinking I could switch out the Sherwood amp and use that one with the speaker and enclosure.

Also, I have my eye on a Bose pre-amp that the guy who's selling it syas he had on a subwoofer. Any thoughts on that idea? Can I in fact boost that signal at all with good results, or should I just suck it up and buy a whole new sub? I REALLY wanted to spend nothing on this, but now I guess I have to...I still want the most economical solution, though.

Thanks-
JC

 

[TosH]

Well, there's only one thing I can think of. Use the Y-cable to connect to both RCA connections on the back of the sub and set the sub level to "MAX" on the receiver. Other than that, I'd look into getting a new sub with auto-on-off settings.

As you may have noticed, there's very little noise with the Panny receiver with digital inputs as opposed to analog sources (like your VCR). As a result, your sub is more likely to turn itself off playing from a digital source at low volumes. I'd say just suck it up and get a new sub. I use the Parts Express 10" 100 watt sub (aka Tiny Mity II) with my XR45 receiver with great results. I just leave it set to on all the time which is not a problem as you get no hum from the receiver on digital sources or when the receiver's off, so you'll never notice it. I did write a little review posted on this forum if you decide to shop around for an inexpensive replacement sub.

 

[TosH]

Forgot one thing. You could also connect your DVD player to the receiver using a 5.1 analog connection and you might get the sub to stay on. That is if you don't mind the hit in sound quality you'd take using analog over a digital connection.