My sub wont work reliably with PCM 2-channel - Rotel RSP-1570

[TORC]

I'm new here as well as to decent audio in general and am looking for some help. I've read the various manuals (a number of times now), tried different settings and have searched but still can't get my sub working reliably when playing PCM 2-channel music through my RSP-1570.

I'm playing Apple Lossless audio through AirTunes (AirPort Express). Though I haven't tested my new setup extensively yet, the sub works in surround modes.

I have:

RSP-1570
RMB-1575
CM9 fronts
CMC2 centre
CM5 rears
CM ASW 10CM sub

Everything I've read says that I should be able to have the sub working with 2CH stereo and when I'm playing PCM 2-channel I can see the "SW" light on the processor screen - so I'm thinking that I should be able to have the sub working.

Fronts are set to LARGE, centre is set to LARGE and the rears are set to small.

I'm not looking for massive bass but I want the sub to give my music a little more punch down low. I was happy to have the sub just take over the low frequency stuff (crossover at the default 40Hz) but it simply didn't work. I then set the sub to "max" to have normal bass duplicated by both the subwoofer and any LARGE speakers but that didn't work either.

Here's the weird thing though - I then noticed that if while I'm playing a track I change the sound mode to a surround mode (pressing the DTS Neo 6 button on the processor) the sub (and other speakers) come in THEN while still playing the track if I change back to PCM 2-channel (pressing the 2CH button on the processor) the sub stays on for the rest of the track. When I pause or play another track, the sub's off again.

What on earth is going on? I don't want to play my music through a surround mode, I just want the two front speakers to do everything they can and add a little sub to that.

[mvdveek]

I suggest putting all the speakers on SMALL. The CM9 is not a true full range speaker.
And by setting to speakers to large you tell the processor to not send a signal to the subwoofer.

[htsteve]

TORC,

First of all, welcome to the forum! :T


As to your issue, I have a question. Do you have both a DSP Stereo mode (i.e. one that plays the mains + the sub) as well as a pure stereo mode (mains only, no sub)? My pre-amp does.

In reading the Rotel RSP-1570 manual, page 32, this seems to be the case for the 2 channel. No DSP processing. That means pure stereo and no sub.
However, page 31 seems to indicate there are four 2 channel modes. The first one sounds like the one you are after, 2 channels with bass management. You might need to press the 2 channel button on the front panel to cycle through these until you get the right one. I also believe you can do this from the remote via the surround mode button. Page 33 seems to speak to this.

I also agree that you need to set the all your speakers to SMALL. While the CM 9's are very nice, they are not full range. Leave them at small with a crossover to the sub.


Hope this helps.

[TORC]

Thanks for the replies and welcome

I tried setting all the speakers to small but it didn't help. Same problem

According to page 31, "2CH Stereo" retains the capability to route bass signals from the front speakers to the sub.

My default for this input is "PCM 2CH" set on the OSD. When I switch to this input, "STEREO" is displayed on the screen, along with "LF, RF and SW". If I then press the "2CH" button on either the remote or the unit, it displays "BYPASS", (Analog 2 channel bypass) removing the subwoofer indicator. The button just toggles between these two modes. So, it appears that these 2 modes are the only 2-channel modes and "STEREO" = "PCM 2CH". As soon as I play a track, the screen goes from "STEREO" to "PCM 2CH" and pressing the "2CH" button has no effect but pressing any of the surround buttons does.

As I said, I can actually get PCM 2CH sound out of the front two speakers + sub but to do that I have to start a track, change to a surround mode (so that the sub starts working), then change back to PCM 2CH (the other speakers switch back off but the sub continues working)... then have to repeat again for each subsequent track. So, I KNOW that PCM 2CH can send to the sub, it just wont do it without all this hassle.

Needless to say, I'm VERY disappointed. Basically, I can't even play stereo music through my 2 largest speakers + sub. That's beyond comprehension to me. SURELY it must be an ignorance issue on my part? Surely a company wouldn't have a product out there that can't even do this and surely if it did, MANY others would have picked up the same issue.

I have checked and the firmware is way out of date (on a brand new unit :roll: ) but I can't find anything in the release notes (that I understand at least) pointing to this issue being overcome by any firmware releases. I'm very reluctant to update the firmware. If it fails I have a brand new brick that I can't give back. At this stage, I'm leaning towards taking it back and going for another brand. Maybe I should go back to SONY 8O - Never had a problem simply playing music with SONY units in the past. It shouldn't be this hard (or impossible?) to listen to music through 2 speakers + sub.

[maxwebster]

It may be that the "auto" setting on your sub is not kicking in to activate the sub in stereo for whatever reason, try the "on" setting and you should be fine.

[TORC]

The sub comes on fine with a 12v switch.

I'd try what you've suggested anyway but as of 5 minutes ago, I now have a brand new bricked RSP-1570. Firmware update never completed - machine will now not power on. Forced update doesn't work either.

Rotel FTL

[hifiguymi]

Are you using a USB to serial adapter for the firmware update? If so, what operating system are you using and adapter. Make sure the drivers are up to date for the USB to serial if you are using one.

I'm assuming you took the top off and pressed the little button on the digital board in the RSP-1570 when doing a forced upgrade. If not. make sure you do that.

As for the initial problem, I've not experienced that before. You said the sub stopped working when you changed tracks. What source are you using?

Eric

[TORC]

^ Windows 7 32 bit. Belkin adapter. Passed communication tests fine but wouldn't complete the write. Gave it 15 minutes. Tried again. Then also took the cover off to press that little button to try a forced update. That didn't work. Tried again. Followed the procedure.

[hifiguymi]

My guess it's the USB adapter. I have a Belkin and it's just doesn't work with Vista and 7 when trying to do Rotel updates. I have bricked a couple of units before I figured out it was the Belkin that was doing it. I was able to do forced upgrades on each piece with the right gear and bring them back to life. It's a pain but but I'm sure that's the problem with the update. You will either need to get a different USB adapter or find a computer with a serial port.

Eric

[TORC]

Interesting. I've used the belkin adapter many times with this same laptop for communications/flashing with MoTeC gear and a pda without problems (once I got the latest drivers). Also as I said it had no problems passing the connection test with the Rotel.

I just got off the phone with my dealer. He's got an RSP-1570 that he's been using for 2 months in one of his rooms so we're going to see if we can get 2CH + sub working on that.

[rashad01138]

RSP-1570 Speaker Setting

I am using B&W 7 series for fronts (703) and HTM7 and 6 series (686) for back. What setting should I have it at? All Large speakers or all Small speakers. Thanks.

[TORC]

All sorted

Received some excellent customer service today.

My dealers 2 month old demo processor running the same old firmware as me has exactly the same problem.

Rang the distributor who was surprised that we both had such old firmware but hadn't heard of the problem. He agreed that it sounded like a firmware issue.

Regarding my now bricked processor: Even though the flashing instructions state that the flash may take up to 5 minutes, the distributor mentioned to me that he'd seen it take over an hour when a serial to USB converter is used. The longest time I left a write for was 25 mins so there's a chance that re-flashing it and leaving it for 1hr+ may actually work.

It doesn't matter though because I just picked up a new processor with the latest firmware directly from the distributor and it works perfectly

Time to finally kick back 8)

[htsteve]

I am using B&W 7 series for fronts (703) and HTM7 and 6 series (686) for back. What setting should I have it at? All Large speakers or all Small speakers. Thanks.

All small. These are very nice speakers, but are not truly full range. I am assuming you have a sub to handle the low end.


Hope this helps.

[htsteve]

TORC,

That is good service and I'm glad it has worked out.

[hifiguymi]

Interesting. I've used the belkin adapter many times with this same laptop for communications/flashing with MoTeC gear and a pda without problems (once I got the latest drivers). Also as I said it had no problems passing the connection test with the Rotel.

I just got off the phone with my dealer. He's got an RSP-1570 that he's been using for 2 months in one of his rooms so we're going to see if we can get 2CH + sub working on that.

It has to do with the USB adapter's drivers and the loader. The adapter can work fine for one piece of gear and not for another. I can use the same USB adapter on a 10 Series Rotel with the older loader and it's fine. If I use the new loader with either a 10 Series or 15 Series it locks up the unit. It's one of those Windows incompatibility issues.

Eric

[hifiguymi]

Received some excellent customer service today.

My dealers 2 month old demo processor running the same old firmware as me has exactly the same problem.

Rang the distributor who was surprised that we both had such old firmware but hadn't heard of the problem. He agreed that it sounded like a firmware issue.

Regarding my now bricked processor: Even though the flashing instructions state that the flash may take up to 5 minutes, the distributor mentioned to me that he'd seen it take over an hour when a serial to USB converter is used. The longest time I left a write for was 25 mins so there's a chance that re-flashing it and leaving it for 1hr+ may actually work.

It doesn't matter though because I just picked up a new processor with the latest firmware directly from the distributor and it works perfectly

Time to finally kick back 8)

Glad things are now working properly. It does sound like there was a bug in an earlier version of the firmware that has been corrected and it didn't make it in the release notes.

Kudos to your distributor for taking care of the issue and making sure you are happy.

Eric