Have you guys heard about this yet? SVS+/samson/receiver problems

Discussion in 'Archived Threads 2001-2004' started by jeff lam, Feb 8, 2002.

  1. jeff lam

    jeff lam Screenwriter

    Joined:
    Jun 4, 2001
    Messages:
    1,798
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    San Jose, CA
    Real Name:
    Jeff Lam
    It seems several people are having problems getting good volume from their subs with the S1000 at max and their receiver sub out at max. This gets me to thinking about sub output voltage and impedance vs. amplifier input sensitivity and impedance. Can someone explain how this works and what we should look for in an amps input sensitivity/impedance to match out receivers output. How do you determine if they will match well.
    http://www.hometheaterforum.com/htfo...threadid=44907
     
  2. Dan Hine

    Dan Hine Screenwriter

    Joined:
    Oct 3, 2000
    Messages:
    1,312
    Likes Received:
    0
    Trophy Points:
    0
    Before Reading, please see my edit at the end of this reply. I left my original text so Tom V's reply later on will make sense.
    I've been keeping up with it somewhat. To be honest though, I don't buy SVS's answer. For anyone who hasn't read the thread, the basic idea, if I am reading it correctly, is that the CS+ subs are not producing as much bass as previous versions because of the receivers and pre/pro's subwoofer line outputs not having enough gain and thus not matching well with the pro-amp inputs. I mean NO disrespect to Tom or Ron, but this problem seems to only be coming up with people who bought the new CS+ subs. Many of the users are saying they didn't have the problem before with a samson/CS combo. So why is it just now becoming an issue? Are the new drivers not sensitive enough so the lower gain is causing a problem? If so, that seems like a step back and not a step foward. If I misread something please let me know as I do not want to seem like someone pointing the finger. Especially with the good customer service that SVS has shown in the past.
    Dan Hine
    EDIT: I replied to this thread before:
    1) I had read other threads about happy CS+ users
    2) More information had come up in the thread refering to some owners not properly calibrating/incorrectly setting up their subs and amps.
    Tom V, Vince Maskeeper and others have since added a lot of helpful information to the discussion and it seems very few users are having an issue and even those that are will have a VERY cost effective solution. Gotta love that SVS customer support and the many knowledgable users on the HTF!
     
  3. Brian Bunge

    Brian Bunge Producer

    Joined:
    Sep 11, 2000
    Messages:
    3,716
    Likes Received:
    0
    Trophy Points:
    0
    Dan,

    One variable you may have missed is that some of the users also moved from the Samson S700 to the S1000. Don't have any clue why that would make a difference unless it requires a higher input level to get going.

    Also, I'd assume that the drivers in the CS+ are made for higher excursion/power handling so it's quite possible that they themselves aren't as efficient as the drivers in the original CS line. But that really shouldn't be a factor here as either of the two Samson amps should have plenty of power.

    Brian
     
  4. Vince Maskeeper

    Vince Maskeeper Producer

    Joined:
    Jan 18, 1999
    Messages:
    6,499
    Likes Received:
    0
    Trophy Points:
    0
    This issue has come up before-- actually often, when mixing proamps and home receivers. Usually the receiver have enough juice- but sometimes they don't.

    What Tom is saying is dead on. Notce the first guy had the amp input gain knobs at 1/2-- it should be all the way up.

    Check the archives- there are a few topics that talk about this idea.

    -Vince
     
  5. jeff lam

    jeff lam Screenwriter

    Joined:
    Jun 4, 2001
    Messages:
    1,798
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    San Jose, CA
    Real Name:
    Jeff Lam
    Also, many of the reviews of the CS+ are great and spacifically state the CS+ is more powerful and louder than the CS. It seems most people are fine but a few have problems. So what do I need to know about the Pro Amp I plan to purchase and if it will go over well with my Yamaha receiver?
     
  6. Rick Radford

    Rick Radford Supporting Actor

    Joined:
    May 12, 2001
    Messages:
    642
    Likes Received:
    0
    Trophy Points:
    0
    Vince,
    >Notce the first guy had the amp input gain knobs at 1/2-- it should be all the way up.<
    I've asked about this before and don't recall ever getting a response... ie, why is it necessary to have the gain at max on the Samson?
    If you have an EQ between the receiver or pre/pro and the Samson, you may not be able to use full gain on the Samson. The gain control on the Samson becomes your sub trim control, and is the only way I can see to calibrate the sub with the rest of the speakers.
    (the receiver's sub trim and MV set the input level of the EQ). This may not be the only way to set the input level to the EQ, but if there's another way, I'm not aware of it. [​IMG]
     
  7. Vince Maskeeper

    Vince Maskeeper Producer

    Joined:
    Jan 18, 1999
    Messages:
    6,499
    Likes Received:
    0
    Trophy Points:
    0
    Rick,

    Amp volume should be all the way up because it is not a volume knob- it is an input gain. If you lower it, you raise the amount of voltage needed to get the amp going.

    Usually, I don't trust an amplifier's input pad (especially on cheap amps), and don't use it unless I absolutely have to! So, I would use the amp with the input knobs turned WIDE OPEN, and let your preamp have control. By having it wide open, the filter on the input is essentially bypassed- and you get clean signal flow from the receiver to the amp.

    If you find that you cannot possibly get your Preamp sub output backed off enough to allow you to get everything even, then consider lowering the amp input knobs. But if my Preamp could dial in calibrated level with the amp's inputs WIDE OPEN, I would absolutley run it that way!

    I'm not sure why you need to get a specific level to the EQ- you should be able to adjust sub volume with the trim controls in teh receiver without effecting if the signal is eq'd/not eq'd... the EQ should deal with the signal no matter what.

    These items are designed to have volume regulated at a preamp stage. IN the pro use, the volume would be regulated by a console, passed to the EQ, and then onto the amps. You should be able to adjust the levels at the receiver without problems.

    Unless I misunderstood your question.

    -V
     
  8. Vince Maskeeper

    Vince Maskeeper Producer

    Joined:
    Jan 18, 1999
    Messages:
    6,499
    Likes Received:
    0
    Trophy Points:
    0
  9. Rick Radford

    Rick Radford Supporting Actor

    Joined:
    May 12, 2001
    Messages:
    642
    Likes Received:
    0
    Trophy Points:
    0
    Vince,
    >Amp volume should be all the way up because it is not a volume knob- it is an input gain. If you lower it, you raise the amount of voltage needed to get the amp going.<
    That helps me understand why the Samson is recommended to run wide open. Thanks!
    My equipment chain is as follows:
    Onkyo 989 -> BFD1124p equalizer -> Samson S700
    >I'm not sure why you need to get a specific level to the EQ- you should be able to adjust sub volume with the trim controls in teh receiver without effecting if the signal is eq'd/not eq'd<
    I'd guess the DACs need a certain input level to work properly? I dunno.
    According to BFD customer support (regarding the input level):
    *************
    "you should use an output from your system that is before the main volume pot.
    -30 is a little too low to detect feedback filters. For parametric equalizer use the input level should come up to -10, if you are in -10dBV mode."
    *************
    There is a note in the manual that says too low or too high input levels aren't optimum. It says to set the input level to where the top clip LEDs flicker rarely.
    In order for my system to do that, I set the Master Volume of the receiver to where I've previously calibrated ref level and crank up the sub trim until I get the input level specified.
    Then the only way I know to adjust the sub's calibration is to modify the gain on the Samson.
    Is there a better way to do this? I'd like to get my Samson gain cranked back to max. [​IMG]
     
  10. Tom Vodhanel

    Tom Vodhanel Cinematographer

    Joined:
    Sep 4, 1998
    Messages:
    2,215
    Likes Received:
    8
    Trophy Points:
    0
    >>>I've been keeping up with it somewhat. To be honest though, I don't buy SVS's answer. For anyone who hasn't read the thread, the basic idea, if I am reading it correctly, is that the CS+ subs are not producing as much bass as previous versions because of the receivers and pre/pro's subwoofer line outputs not having enough gain and thus not matching well with the pro-amp inputs. I mean NO disrespect to Tom or Ron, but this problem seems to only be coming up with people who bought the new CS+ subs.>Many of the users are saying they didn't have the problem before with a samson/CS combo. So why is it just now becoming an issue?> Are the new drivers not sensitive enough so the lower gain is causing a problem? If so, that seems like a step back and not a step foward.
     
  11. Kenny WH

    Kenny WH Stunt Coordinator

    Joined:
    Jun 27, 2000
    Messages:
    50
    Likes Received:
    0
    Trophy Points:
    0
    We use to have a similar problem in the autosound community, before companies started making their headunits with high voltage line outs. We use to use seperate line drivers to increase line voltage that reduced the need to crank up the amp gains which in turn helped overall sound quality.

    In my theater I have the Sampson S1000 pushing two SVS Ultra's, and another amp running multiple tactile transducers. The sub out on my Denon 5800 is y'ed to send signal to both amps, however I noticed a distinct drop off in output in the Sampson when I did this. I assume it's because the signal is being divided between the amps.

    Now my question, I have a Phoenix Gold PLD-1 line driver(adjustable up to 6volts rms) and an AC-DC converter lying around. Could I use the PLD-1 on the sub out of my receiver to boost the voltage?
     
  12. BobAlbano

    BobAlbano Second Unit

    Joined:
    Dec 10, 2001
    Messages:
    293
    Likes Received:
    0
    Trophy Points:
    0
    Just to clear somethings up about the SVS CS+/Samson combo! I'm one of the people who was having a problem matching the Samson to the sub-out of my Denon. I was in the process of moving so I didn't hook up my ART351 EQ to the subs during the initial setup. I corresponded daily with TV on possible solutions to my problem and he always got back to me in a timely manner reasurring me that I would be happy with my decision to upgrade from a 20-39pc. This past weekend I was sitting around killing time when I decided to hook up the ART351 and see if that helped. BINGO, the ART351 has a gain on it that boosted the signal to the amp and can I tell you the cs+ came to life![​IMG] I don't know about the rest of you, but it ended up being a problem with my equipment that SVS had no control over. Tom and Ron take great pride in their Subs and the rest of the products that they sell and it shows. It's not right for people to be throwing around insinuations that they are having problems with their products. If they are only having a problem with 1-3% of all of their products they should be commended.....I bet my bottom dollar that company's like GM & Ford could only dream to have only 1-3% of their cars come in for waranty work! Keep up the good job guys! ONE PROUD SVS OWNER
     
  13. KevinHunt

    KevinHunt Stunt Coordinator

    Joined:
    Aug 31, 2000
    Messages:
    121
    Likes Received:
    0
    Trophy Points:
    0
    Well with forums such as these paired with the all powerful internet, things can turn into a rumor mill and speculation can spread so fast you wouldn't believe! My suggestion is for the folks to read Vince's comments in the other thread. Many of the folks who THOUGHT they were having this problem, were not. They either had not properly calibrated their subs yet or they were expecting the CS+ to be louder at the same calibration as their previous sub. 75dB is 75dB is 75dB, assuming the room had not changed and the woof in the same location. Crank things a little bit or throw it some more demanding material and the differences will be readily apparent. As stated the voltage/impedence problem is a reality but not a new problem at all and unfortunate for the very minute number of people it affects, and a solution is in the works.
     
  14. Steve Stogel

    Steve Stogel Supporting Actor

    Joined:
    Jul 19, 2000
    Messages:
    600
    Likes Received:
    0
    Trophy Points:
    0
    >>>Crank things a little bit or throw it some more demanding material and the differences will be readily apparent.
     
  15. SVS-Ron

    SVS-Ron Screenwriter

    Joined:
    Jun 2, 2001
    Messages:
    1,074
    Likes Received:
    0
    Trophy Points:
    0
    Bob, Kevin, Steve, (and knob jockies everywhere ;^)

    I think you summed it up well. Of the hundreds of Plus subs that have gone out already I think we're down to one or two guys that might still have a problem.

    As has been well noted here, if you have a 20-39CS, a 20-39PC, a 20-39CS-Plus and a CS-Ultra and they are all calibrated the same, in a smallish room and not driven to beyond the capability of the the least of these then they'll sound far more alike than different.

    Add a big room, hot calibration, high levels and really deep bass there is no doubt you get more when you pay more.

    A sub like the CS-Plus loves to be pushed to levels that would leave a CS in the weeds (within reason, don't just drive it to insane levels till you smell the voice coil burning). I think most folks like Bob have broken the code on this. For others we are still working on some cool devices designed by industry audiophile guru Phil Marchland to add signal boost, adjustable phase, and adjustable subsonic filter (with twin outputs too for folks that have amps without the parallel mode of our Samsons). This won't be as inexpensive as we first hoped but for those situations where you need all or some of those key tools it'll be the Swiss Army knife of subwoofer trouble-shooting.

    Stay tuned for more on that device in the next couple weeks.

    Ron
     

Share This Page