I am on my second sub and I am still having the same problem- -
My receiver is a Marantz SR-14EX and my sub is a Martin Logan Depth. I have tried various settings on my receiver and can only get (what seems like random) activation of my sub when playing a CD. I have had the same problem with my old sub a Boston Accostics. I have got to beleive the problem lies within the receiver settings, but can't seem to get the right combination. What is the best way to maximize my settings. Even if your receiver isn't the same as mine I would appreciate any feedback. Thanks for reading my thread.

Your reciever is probably set for a pro logic or DTS mode which only sends signals to the sub that are encoded for movies, don't know because I don't know your reciever. It sounds like you are using the "subwoofer out" jack on the reciever. If your reciever has a "7 channel stereo" type mode it will probably solve the problem. Select the 7 channel stereo mode for the CD input. Most recievers will remember the mode that they are in depending on which input is selected (they remember the last mode selected for each input) if none of this make s sense or doesn't work, you can always send the sub a channel of high level or speaker line input providing it has that capability. This will ensure that low frequencie signals appear at the sub all the time

Actually, I would guess that the front speakers are set to large, which means the stereo signal from a CD doesn't have anything that is sent to the sub. This is part of the reason I have my sub output from the front speakers instead of the sub output.

Many receivers allow you to set the bass management for the front speakers to a setting labeled "both" or "LR + LFE" or something like that. Which would allow the bass to go to both the fronts and subwoofer; best setting for towers and a sub if you are using the LFE output.

Another possible problem could be what you are using to play cd's. If it is a dvd player that is capable of SACD or DVD-Audio, then the bass management in the player could be setup to output bass differently than what you want. This is a slim possibility, but since you didn't say what you were using as a source, there's a chance.

I believe that this is the correct answer. I am currently having the same problem. The problem goes away when the soundfield is changed away from a movie mode to a music mode. This is really quite annoying though.

Do you have the same problem when watching TV? Because most TV shows don't have the 5.1 encoding and then, like CD's you wouldn't have bass. It is really annoying, because when watching TV you want the surround sound to function in a Dolby or DTS setting.

Regardless of the whether it is set to Dolby Por lOgic II or DTS Neo 6, if the bass management is set correctly in the receiver any bass frequencies in the signal that are below the crossover frequency setup in the reciever should be output to the subwoofer. That is the whole point of bass management in a receiver. If it is not setup correctly than bass that normally would be going to the sub will not go, which is what is happening.

The proper way to set-up your sub and receiver is partially dependent on the front speakers you are using. If you have full range towers in the front, then the crossover frequency can be set relatively low, although I usually set it to the THX standard of 80hz. If you have bookshelves this would also work. The first step would be to set the volume and crossover frequency to top dead center on the dials of the back of the depth(nice sub by the way). Then, if it was my receiver, set the crossover freq. to 80hz, and the LFE setting to both or main + LFE(see earlier post). The next step to get it right would be to use an SPL meter and test disc to level the speakers and set the subwoofer volume at the correct level in the receiver(not on the sub).

Sorry for the long post.

Hoop, I agree completely with what you are saying, but I have already done that stuff and still there in almost no bass when watching TV or CD's when my Denon Receiver is set to Prologic modes.

I have the crossover set to 100 because the LR's are inwalls and they can't handle a lot of bass. I have the LFE setting to sub only.

Subwoofer is set to yes.
Change the soundfield to 5 Ch St and the sub is very very loud.

As per my earlier post, is there any chance you are using a DVD-audio or SACD player for your cd player? Otherwise, I don't know. In my store I have many receivers and have never had a problem getting proper sub volume off of cd's regardless of the surround mode.

Yes the CD player is a Denon DVD player. I will check that out, but there is the same problem when listening to TV. So I think it is internal to the receiver. On another post somebody mentioned setting the LR speakers to Small, but I thought that would simply cut bass from the LR's not add more to the Sub.

It should cut bass to the Mains and send those frequencies to the sub, but that is why the "both" setting should be working. Although if you are crossing over your fronts at 100hz, you could set them to small; I would have to check, because I think that cuts the bass at 120hz, which might leave a little gap in response.

Did not know it was doing the same thing out of TV. That is odd. It should be working out of Pro Logic II, because if 7-channel stereo is providing adequate bass, then the bass is inherent in the main Left and Right two channel signal. The receiver is not adding bass in that mode.

Sounds like it is still a receiver set-up issue, but I am stumped.:(

Just a side note to the conversation. When we use the DVD player as the CD player as well, we always run audio to both inputs.

That is less confusing to the customer. They don't have to keep switching the sound fields back and forth. If they want to play a CD... they hit CD...... If a DVD, then they hit DVD and unless someone has messed with them, they will have the proper sound field for what they are listening to automatically.

Makes life more simple for them.

Warren, that is a great idea, now just if receivers could all have 10 optical inputs and 10 coaxial digital inputs!

I am going to do that more often now that you mention it.

Hmm, maybe we're approaching this from the wrong angle. Are you sure these sources actually have bass? When I watch some TV shows, it goes from zero bass to tons in the commercials. Problem is the source, not my equipment.

And I thought I was the only one who had thought of it :-)
Iain

I have been doing that for years.