1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Marantz SR4300

Discussion in 'AV Receivers & Amplifiers' started by PBergin, Jan 17, 2003.

Tags:
  1. PBergin

    PBergin
    Standard Member

    Joined:
    Dec 3, 2002
    Messages:
    20
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    1
    Ratings:
    +0
    Hi,
    I recently bought a Marantz sr4300, I am very happy with it but I have one small anoying problem.
    When ever I change source (eg from tv to DVD) or when on DVD if I change chapter (eg move up or down one chapter) there is a loud thump from my sub.
    What could be causing this?
    I am a newbie so it could be a wiring problem, it sounds great apart from that.
    The sub I bought is a Monitor Audio ASW100, there is a L and R input on the back of the sub and the amp only has one outout (ie one cable) I just connected it to the R input, is this ok?

    Cheers
    P
     
  2. James45

    James45
    Standard Member

    Joined:
    Sep 21, 2002
    Messages:
    2,844
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    59
    Location:
    Taking Care of Business
    Ratings:
    +0
    yep either of the sub inputs are fine, you could get a y splitter and use both but that's only to increase the sensitivity of the auto signal switch off facility most subs have.
    as for the thump it does sound as though something ain't right. I have a Gallo MPS-150 sub connected to a marantz 5300 and it's quiet as a mouse during chapter changes and source changes... bloody loud the rest of the time!:D

    sorry but i have no idea what's causing that.
     
  3. adox

    adox
    Banned

    Joined:
    Nov 5, 2002
    Messages:
    688
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    19
    Location:
    dublin
    Ratings:
    +0
    i have the marantz sr4300 too and don`t have that problem.
    may be it`s your sub?
     
  4. sounddog

    sounddog
    Well-known Member

    Joined:
    Dec 11, 2002
    Messages:
    3,370
    Products Owned:
    0
    Products Wanted:
    1
    Trophy Points:
    107
    Location:
    Leicestershire, UK
    Ratings:
    +461
    Just a thought ... but does your Sub have anykind of Auto Power / switching? If so, try disabling it.

    Victoria
     
  5. PBergin

    PBergin
    Standard Member

    Joined:
    Dec 3, 2002
    Messages:
    20
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    1
    Ratings:
    +0
    It does have Auto switching, but I dont think there is any way to turn it off, I will take look at it manual tonight and see if it can be turned off.

    Cheers,
    P
     
  6. cribeiro

    cribeiro
    Well-known Member

    Joined:
    Nov 2, 2002
    Messages:
    2,797
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    A Spaniard in Germany
    Ratings:
    +307
    I may have an answer, but I am not sure... It can be if only your sub is active, that is, if it has its own internal amplifier. I have a Magnat a30 subwoofer, and I am very happy with it. I combine it with a Yamaha rx-v530 amp, although I would like to go for the marantz 4300, my speakers wouldn't feel the difference, so I will upgrade altogether some day far away... Anyway, the matter is that I also get a thumb in the sub, now you may wonder what is the relation, since the setup is not yours... Well, I get it but whenever I turn on or off the lights in the room. I think that the tumb is not caused by the amp, but by the electrical installation of your house. Whenever you switch an electrical device on or off, there is created an extra intensity of current called (I translate from spanish, don't know the exact term in english...) opening or closing extra current. It is something like the inertia of any body in movement but in current terms... When you are moving, you tend to keep moving (try your brakes in an icy road), and when current is flowing, it tends to flow (and when stopped, it tends to be stopped, isn't it difficult to get up every morning? :)). This extra current is what you are hearing. I think that the subs are in general extremely sensitive to this because they do not carry the proper protection, which probably the amps do (this is why I don't hear it in the main speakers, which do not have an extra current supply). You may try to turn the lights on and off, while the sub is on but the amp is off, and hear what happens.
    Why it happens when you switch font in the amp? Well, this would mean that the internal circuitry of the amp is not well protected against current fluctuations, so I recomend you to unplug it whenever a storm is near... But I really don't know. I just tell you my own experience, and the explanation why that usually happens. Could be that you have a defective amp or sub...
    I know how to solve my problem, and thus yours if it is the same: buy a special filter. If it is a matter of defective material, I hope you still have it under guarantee.
    About the filter, I don't know how it is exaclty called in english, so I cannot help you any further. Should be a device hwere you plug your hifi, and which you plug to the current network.
    It is supposed to avoid any fluctuation in the current signal, and it may be something very expensive or rather cheap, depending on the power it must deliver and on its performance doing the job.
    About the auto switching, mine does have it, with the three options (off, on, auto), but it is not an issue since the auto-off happens after 15 min. without signal... Don't know about yours, but should be something similar according to the common sense. But it could also be!
    Ok, lots of thoughts, I hope you can learn something, because I did it just by writing.
     
  7. cribeiro

    cribeiro
    Well-known Member

    Joined:
    Nov 2, 2002
    Messages:
    2,797
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    A Spaniard in Germany
    Ratings:
    +307
    Some news: since once I was a system administrator in a computer room, I know a little about protection, and I learnt there that there are certain devices called UPS to protect computers against this kind of things and also other bigger problems, as well as to keep them working if there is a cut in the network (sorry, i don't know the proper english words for this technical things). It is a rather expensive thing, but I am sure it would be also fine for a hifi, although maybe not very adequate. It was the first thing I thought about when I noticed about my problem. I guess you can find better help in a specialised shop (as I said, if your problem is the same than mine).
     
  8. sounddog

    sounddog
    Well-known Member

    Joined:
    Dec 11, 2002
    Messages:
    3,370
    Products Owned:
    0
    Products Wanted:
    1
    Trophy Points:
    107
    Location:
    Leicestershire, UK
    Ratings:
    +461
    I'm not positive, but I don't think a UPS would work well in audio setup because of the way that they work. A PC (or similar) generally uses a switched mode power suppy where as an amp will use a transformer based power suppy.

    Suffice to say I think you will cause problems ... if I put my mind to it I could tell you all about sine-waves and stuff ... but it's been too long since I did electronic engineering at Uni and such things have been relegated to the DLT of my brain :)


    Victoria
     
  9. Lithian

    Lithian
    Standard Member

    Joined:
    Jan 16, 2003
    Messages:
    38
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    9
    Location:
    Edinburgh 3
    Ratings:
    +0
    Anyone want to hear my theory?

    Based on what happend with an old hifi i had (anyone remember Trio?), when you switched it off the speakers would thump.

    I have an idea why it did this, it is based on the speaker.

    Excuse my lack of technical terms btw.

    When the speaker switches on it primes itself up, imagine a spring, you pull it out a bit, that is it primed. Durning normal operation the speaker swings back and forth using the primed position as a middle point to move from (ie, it springs).

    Now, the thump. When you switch off, change source etc. There is no signal to the speaker. It 'un'primes rather rapidly giving you a thump from the cone.

    I can only assume that other speakers are more refined and this release of the speaker is less rapid.

    Just a theory.

    Oh, and cribeiro was talking about a Surge protector (UPS' have this built in as well as the battery and the electronic trickery) which although dosn't go with my theory is something i always recommend to keep your expensive toys safe.
     
  10. cribeiro

    cribeiro
    Well-known Member

    Joined:
    Nov 2, 2002
    Messages:
    2,797
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    A Spaniard in Germany
    Ratings:
    +307
    Might be that, Lithian. As I said, I am not an expert in that, it is only that I learnt how it was for computers, so there should be something like that for any other electrical device. But I was pretty sure it would do fine! Actually, I would be interested in a further explanation, sounddog, if you don't mind and you can retrieve things from the DLT of your brain. I am not an engineer, but a nuclear physicist, so that is away from my field, I had 1 hard course in Electronics, but it doesn't help. Nevertheless, it makes me wonder, why cannot it be? So if you don't mind, send me a private message.

    About your theory, Lithian, it makes some sense, since the switching on would add some constant current, although very little, I think it is called offset. The ideal situation would be zero current before music is sounding, but I don't think it is like that, and you can actually hear a hissing when you turn up the volume while no music is sounding, which means that it is not even continuous (a constant current would make no sound). This means that when you turn on, you go from zero to that constant, and there you have a variation that changes the position of the membrane of your speaker, what you called a prime. this movement of course can produce sound. In that sense, the problem would be the amp, and not the electrical installation of the house.
     
  11. sounddog

    sounddog
    Well-known Member

    Joined:
    Dec 11, 2002
    Messages:
    3,370
    Products Owned:
    0
    Products Wanted:
    1
    Trophy Points:
    107
    Location:
    Leicestershire, UK
    Ratings:
    +461
    Sorry if this is wrong but as I said before I'm doing this from memory ...

    True AC current (as we all know I guess) is a complete sine wave.

    A UPS takes this, converts it to DC and charges the internal battery. The DC current is then converted back into AC using electronics. Most (probably all but I don't want to say call cause if I do someone will inevitably prove me wrong) UPSs don't produce a perfect sine wave ... if you look at the output from a UPS the waveform will be somewhat between a sinewave and a squarewave. This works fine on PCs where all that happens if that the AC signal gets converted back to DC at various voltages, but if this signal was shoved into an Amp, I think that you would get lots of distortion due to power problems.

    As for the bit about the "thunking" in the speakers being caused by the coils discharging themself this is wrong ... it's actually caused by capacitors discharging themselves withing the amplifier ... that energy has to go somewhere and it will (in a badly protected amp) discharge through the speaker coils, making the "thunking" described. A good amp will have protection circuits built in so that before the amplifer discharge their capacitors (or charge ... similar effects can be seen while charging capacitors too) the speakers are actually disconnected from the output of the amplifers.

    Of course non of this is relevant to "thunks" through a active sub as the power suppy shouldn't be affected by changing channels, etc. Did you have the sub before the amp - if so were there any problems then? If you've had no problems with the sub using other amps, I would take the amp back to the store and get them to check it before you do any permanent damage to the sub.


    Victoria
     
  12. cribeiro

    cribeiro
    Well-known Member

    Joined:
    Nov 2, 2002
    Messages:
    2,797
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    A Spaniard in Germany
    Ratings:
    +307
    Thanks for the explanation! I thought that the signal coming out of the UPS was a real sinus!
    Yes, you are right, it looks like a capacitor, I remember now about it at the university, it was real fun with the osciloscope, but we didn't go any further. Nevertheless, I think that Lithian didn't refer to a discharge of the coils, but rather a signal coming from the amp, since you don't really switch on and off a speaker, but I might be wrong, this is just what I understood. And then, that signal can be actually caused by the discharge of the capacitors, or an offset as I said (but I am only guessing, I know that it would cause something like that, but I don't know if it actually happens).
    Very good idea about the sub and other amps, I would suggest the next thing: Pbergin, look for a friend with a similar equipment at home, but without that problem, and bring there both sub and amp of yours. Substitute one of them (sub or amp, obviously not both at once) in his/her system, and check everything. Then, do the same with the other of your devices. If you don't notice any problem, then it is a problem of your electrical installation at home, if you do, you will notice the thump with the defective part. The other possibility is go to the shop where you bought any of those possible damaged devices, and tell them to do the check for you. And, if they succeed, ask them what was the problem, and enlight us! I am really curious about it.
    And thanks for the name "Surge", I will keep it in mind because I think I really need it.
     
  13. EvilMudge

    EvilMudge
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Without wishing to stir things up, it's more likely that you'll get a pure sine wave out of a good UPS than out of your mains socket. Mains is not pure 50Hz by any means. There are all sorts of nasty harmonics littering in there because of the back EMF from the number of devices being switched on and off throughout the power grid. It's also not a constant PTP Voltage, it goes up and down as demand increases and decreases. On a particularly bad night it can drop to less than 200V.
    I'm not saying that all UPS are perfect, but that the better ones make a better stab at giving you a clean power supply.
     
  14. cribeiro

    cribeiro
    Well-known Member

    Joined:
    Nov 2, 2002
    Messages:
    2,797
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    A Spaniard in Germany
    Ratings:
    +307
    Well, as I said, but I don't know, I would expect that, since it is supposed to protect against any fluctuation of the signal. In adition, if as Lithian says, any UPS includes a Surge protector, then it must be a clean sinus, isn't it? MAybe next time I go back to Spain, I will check it with an oscilloscope and some friends :)
     
  15. cribeiro

    cribeiro
    Well-known Member

    Joined:
    Nov 2, 2002
    Messages:
    2,797
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    A Spaniard in Germany
    Ratings:
    +307
    BTW, I have just checked the web for "Surge protector" and there are some at a fair price (20 euro) that can handle the needs of any hifi, so my recomendation is to buy one, I will do it as soon as I can! It protects against any problem you can experience in your electrical installation, from a normal fluctuation of current to a lightning.
     
  16. cribeiro

    cribeiro
    Well-known Member

    Joined:
    Nov 2, 2002
    Messages:
    2,797
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    A Spaniard in Germany
    Ratings:
    +307
    I don't want to be boring and bother a lot, but I have just found this web site, about such a device

    http://www.howstuffworks.com/surge-protector.htm

    where you can learn whatever you want about it, I think. I am reading it right now.
    And yes, this is a boring sunday :) Sorry for too much bothering!
     
  17. PBergin

    PBergin
    Standard Member

    Joined:
    Dec 3, 2002
    Messages:
    20
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    1
    Ratings:
    +0
    Thanks for you help all, it has made for some very interesting reading.
    The amp and sub are brand new, I might call into the shop where I bought everything and see can the check my sub.
    It would probably be best if I improved the way I have power running to everything, I only have a single socket and a big plug board running off this (it powers the tv, dvd, receiver, sky box & VCR). The sub is on the far side of the room with its own socket, there is also a very faint hiss from all speakers when it is quiet, so maybe there is some sort of power issue.
    Thanks again for your help
    P
     

Share This Page

Loading...