Hsu VTF-2 made some popping noises in a movie scene, Is the sub broken? Help!!!!!!!

Discussion in 'Speakers' started by EddyObregon, Feb 20, 2004.

  1. EddyObregon

    EddyObregon Stunt Coordinator

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    Ok I have tried the hsu demo disc and i have tried it on both max extension and maximum output. I plug the 1 port with max extension and unplug for max output. In the demo disc on max extension and the sub set to volume level to about half to see how this sub sounds it does not bottom out but it vibrates my walls and on max output it does the same thing. Today I put the movie Matrix Reloaded and in the freeway seen when one of the agent smith jumps on top of a car and crushes it the bass go's real low and on max output the sub when it goes very low it makes a pop noise that i was like oh my god did the sub break. Now on the same volume when i put the sub on max extension and the volume about the same if not a tad higher the sub does not pop. I have tried this scene a million times on max output and it makes the popping sound every time. I know that I have to calibrate my sub with spl meter that way i dont put the sub way to loud but I had a old infinity and that thing never i mean never popped once. How can this sub be popping. Does this mean that the sub is damaged. I have tried other senes and everything seems fine but I do not want a sub that is going to pop every once and awhile... i did pay 450 for a reason... is this sub defective. Is a sub supossed to pop on certain scenes every once and awhile if the sub is to loud.....
     
  2. Edward J M

    Edward J M Cinematographer

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    Eddy:

    Altering the tune point of the sub also changes the frequency where the woofer will reach its maximum excursion.

    A vented sub reaches maximum excursion above the tune point. As the tune point is approached, woofer excursion begins to drop because it is coupling with the resonator (vent) and its motion is being damped.

    Below the tune point, woofer excursion rises again, but in your case is controlled via a 2nd order high pass filter installed by Hsu.

    In the max-output mode, maximum woofer excursion probably occurs at around 37 Hz. In the max-extension mode, maximum woofer excursion probably occurs around 30 Hz.

    That particular scene probably just happens to hit hard in the 35-40 Hz region and as a result bottomed out the woofer - that is the loud POP you are hearing.

    BTW - creating that loud POP a "million times" is a sure fire way to ruin the woofer. You are exceeding the (admittedly modest) linear motion limits of this driver. As your ears become more experienced, you will begin to notice "dynamic compression" occuring before the driver outright bottoms.

    While you can experiment with placement to try and gain a bit more boundary reinforcement, it seems pretty clear the VTF-2 is not enough sub for your particular needs and HT applications.

    Rather than risk ruining it completely, I advise you to purchase a larger, more powerful sub that will be able to cleanly hit those bass peaks without compression or outright bottoming.

    Regards,

    Ed
     
  3. Zack_R

    Zack_R Stunt Coordinator

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    Eddy, there is also a corresponding switch on the back of the amp that must flipped to match the tuning. The switch should be flipped towards 25 hz when one port is plugged and 32 hz with both ports open.

    Where do you have the switch?
     
  4. CurtisSC

    CurtisSC Screenwriter

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    Eddy,

    Judging by all your posts on the other forums, you like A LOT of bass, and ran the sub way louder/hotter than the rest of your system.

    Have you played with placement of the sub? You mentioned in other threads that when calibrated, it was too low for your tastes. This would likely be the case for any sub you purchased.

    Work with placement of the sub, and calibrating. Many people run the sub 3-5dBs hotter than their mains...you might want to check how much hotter you like your sub.

    If after that, you find you still want more bass, then look at the STF-3!
     
  5. EddyObregon

    EddyObregon Stunt Coordinator

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    so your saying that the vtf2 can only go as loud as it can before it bottoms out. SO tell me why did my cheap infinty 12 inch driver never bottom out. Actually in max extension that scene at the loudness i like it does not bottom out. The sub can get very loud like in star wars phantom menace in the pod race the sub shooked my house and never bottomed out in those scenes. I dotn think it is a mater fo spendign more meny but rather fine tuning it. Let me ask you this though if i had 3 hsu vtf2 and i ran it in max output at the loudness i had it in that scene would all 3 of them bottom out or is this a defect from my sub.. Do you think that because the popping noise happened in 3 occasions do you think it damaged my sub.. also i have a 15x13 room woudlnt this sub be enough my old infinty when it was new would shake my walls and that sub cost like 150-200 dollars and it was a 12 inch driver and that thing never bottomed out..
     
  6. CurtisSC

    CurtisSC Screenwriter

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    that size room should be no problem...but how high is the ceiling, and are there any openings?

    Did you flip the EQ switch when you went to max output mode?

    Without knowing the SPL you are listening at...nobody can tell you if it would happen all the time on three identical subs. I doubt you sub is defective, but without a measurement, there is no way of telling.

    The old Infinity either had protection from bottoming or not enough power to even get there.

    How does the VTF-2 sound compared to the Infinity?
     
  7. Mike Howard

    Mike Howard Extra

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    Eddy,

    I seem to recall some of the expert audiophiles on this forum, in the past mention that cheap sub woofer manufacturers employ some type of limiting circuitry to prevent the sub from being overdriven and bottoming out. Maybe this is why your cheap Infinty never did so. By no means am I an expert in this area, so I could be completely wrong about my assumption.
     
  8. EddyObregon

    EddyObregon Stunt Coordinator

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    it blows it away offcourse... it sounds thighter and lower the infintiy sounds lighter and boomier. trsut me i had the swith in the back flipped correctly and my room is 15x12 with 12 foot ceilings and yes there are openings to the hall way and to the dining room.... Should i claibrate it closer to my speakers. if i do identical then my sub will sound to soft in bass ehavy senes. I liek to feel a little bass and trust me with thsi sub i do i think though that for that sene i had it to loud but i have tried at that volume in other movies and no prob only in that sene really and in max output. Do most people have this vtf 2 in max ext or max output
     
  9. CurtisSC

    CurtisSC Screenwriter

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    Yes you should. It sounds like you like a lot of bass rather than flat response.
     
  10. Sasha_G

    Sasha_G Agent

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    EddyObregon,

    It seems like something is wrong with the sub. Your room is NOT too big unless your adjoining rooms are large and your sitting on the opposite side of the room from the subwoofer. Oh, and it should be in Max Output mode.

    Can you describe the "popping" sound for me? Sounds strange and I know the VTF-2 is one of the loudest subs on the market.

    By the way, its important to know is that output levels are dependent on how far you are from a subwoofer in your room. A bigger subwoofer offers more placement options across a room, but a properly placed 10 inch sub can do fine when placed closely. At half an inch, reaching 120 dB is easy for a 10 inch sub. Accross the room, it becomes impossible. Thats one of the advantages of long interconnects!

    For stronger bass I recommend corner loading, nearfield placement close to listeners, and placing the sub far from unclosable room openings.
     
  11. EddyObregon

    EddyObregon Stunt Coordinator

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    the popping sound was like if the woofer was hitting somethign like the stops or something. Turst me i get plenty of base in the room. My sub was running like 20+ dbs higher than my speakers and i had my sub sounding like if there was a rocket in my house. Question why should it be in max output if you calibrate it to the same levels as your speaker max output and extension will sound similar. Do alot of people here use max output. i do have it in a corner most people have told me that the sub was runnign to hot. No one has told me that there soemthign wrong with the sub
     
  12. EddyObregon

    EddyObregon Stunt Coordinator

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    the bass rattles my house it just happens in that sene but i havet tried like 20 ther movies so...
     
  13. EddyObregon

    EddyObregon Stunt Coordinator

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    On top of my hsu vtf2 bottomling out when it was runnign hot, I tiday noticed when switching from dvd player to my sattelite from direct tv and when i had it low my sub light turn red. When i went to a music channel that had some bass it was still red and didnt turn on until i raised the volume a bit in where it probably picked up the strong bass signal is this normal as well or do i have a hsu vtf2 that has all these issues.....
     
  14. Sasha_G

    Sasha_G Agent

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    Max output mode simply gives your subwoofer more output ability before the sub bottoms out, compresses, etc. Max output is designed for material that is LOUD.

    In particular, it does a few things:
    1) With two ports open and the sub in max output mode, you will give up a little deep bass in exchange for a subwoofer that can play much louder.
    2) The sub will engage protection to avoid bottoming out, at the expense of that deeper bass.

    The scene you played loud on the VTF-2 most likely has a lot of very deep bass that is really pushing the subwoofer to the limits. Even though the VTF-2 has protection in both output modes, there is less deep bass protection in max extension mode.

    The issue about the the light turning red when music is playing...The fix for this is:
    1) Turn the receiver's "subwoofer level" up and turn the volume on the back of the subwoofer down. The reason being that there is less bass in music and TV, and the sub needs a stronger signal. There is often not enough to turn it on.
    2) I don't think this applies to you, but make sure your Left/Right/and Center channels are set to SMALL and the SUBWOOFER is turned ON. This lets the sub get bass from the other speakers, and not just the LFE channel.
     

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