HSU Research Forum (HRF)

HSU Research Forum (HRF) (http://forum.hsuresearch.com/index.php)
-   Hsu Research - Speakers and Subwoofers (http://forum.hsuresearch.com/forumdisplay.php?f=2)
-   -   Whats that annoying Rattle in my VTF3-MK2? (http://forum.hsuresearch.com/showthread.php?t=14799)

95 Silver TA August 20th, 2009 8:14 PM

Whats that annoying Rattle in my VTF3-MK2?
I have had my sub for almost 5 years and use it everyday for an AVERAGE of 1.5 to 2hrs EVERYDAY. (Me and the wife LOVE watching movies) and this sub has greatly increased our enjoyment for our moving watching experience.

I always keep it at the 9 or slightly below the 9'oclock position. For the first 4 yearss I have had it in MAX Ext, then this past year switched it to MAX Output (both ports open). I found I liked the MAX Output a bit better on this sub for my room.

My sub is near field and I noticed in the past two weeks, it started this annoying rattle on some bass (not all) bass scenes in movies. It seems more apparent on scenes where most of the movie is quiet and all other speakers are quiet and there is some bass effect. The wife and I both noticed it was coming from the sub so about week ago I tapped firmly on top of the sub box with my hand and the rattling stopped for 3-4 days. Today we watched Express (football movie on BR) and it started rattling again. I rewond the movie and put my weight on top of the sub and we both noticed it stopped but then started again when I took my wieght off the sub. There nothing sitting on top of the sub to cause the rattling. I also check the subwoofer itself by giving it a slight push and it still seemed new and real tight.

Anyone know whats causing this or have any suggestions?
Is this just normal wear and tear with the box since I have used it so much in the past 5 years and or is it time to upgrade?

Pete_Hsu August 20th, 2009 9:16 PM

Hi Claude, great to see you on the forum, but sorry to hear about the rattle :(

You did set the bass extension switch on the subwoofer amp to the '2 port open' mode, correct?

Try unplugging everything from the back of the subwoofer, remove the 12 perimeter screws along the four outer edges of the amp, and pull the amp out a little bit (by gripping the high level inputs and pulling). Look inside the enclosure for any loose pieces of MDF.

If you or anyone you know has some decent carpentry skills, you could try adding a tall brace inside the enclosure that runs from the top of the cabinet to the bottom of the cabinet.


95 Silver TA August 21st, 2009 4:01 AM

Thanks for replying Peter.

No need to apologize, trust me I have gave this sub some use/abuse in the 5 years I owned it. It probably as much use as someone else who watches movies 2-3 times a week but would probably be equal to 15 years of use. Even if I can resolve it, it sure was one HELL of a Sub that was super clean for the first 4 plus years. Trust me if I have to upgrade, HSU is still on TOP of my list :)

I had a few more questions, so if you could please pm me your phone number and a good time to call, I'll call you.


Ddavidson August 21st, 2009 9:36 AM

Toys and other things
A few years back I had a strange rattle develop in my VTF-3. When I pulled the amp out I soon discovered the culprit ...... inside was a small matchbox car, and a plastic spoon.

Children just love sticking toys and things in really strange places.


95 Silver TA August 24th, 2009 7:18 PM

HSU always seems to amaze me.

I was a customer almost 5 years ago and they still treat me like a new potential customer and a fellow HT enthusiast.

First let me clarify after another weekend with the VTF3-MK2 Sub, I realized that this “rattle” only occurs when most of the movie has a quiet scene but there are some low bass tones for drama type effect. I am guessing these low bass tones that I noticed in the movie The Express and The Traitor is low frequency because my chair shaking like it always does when watching a movie with good bass and my HSU sub. Yesterday we had the newer Hulk movie on (Bluray) and the sub handled it with ease I could not hear any rattle or maybe it was masked by the other speakers playing loud…I don’t know, I do know that movie had some awesome bass and the sub did not rattle. The previous weekend I had the Lord of the Rings Trilogy (Extended DTS DVD Edition) and it rattled in the first movie for a few seconds until I firmly tapped it and it did not do it again through all 3 movies. It could be that its low frequency at a high db that is causing it but it does not sound like chuffing from the ports but more like rattling. As I said, my sub has seen a LOT of hours of use.

I called HSU by the number provided to Peter and spoke to a Leo there that was very helpful and began explain some techniques I could try to strengthen the sub structure if needed. I was on the phone with him for about 20 mins last Friday. He then took my email address and told me he would send me pics on the details. I believe he was taking apart a HSU VTF3-MK2 to get the correct internal measurements and what I would need and send me pics on what he recommends. Today, I got a call from Peter and he wanted to confirm my email address and provide me some more details of what he was sending. We talked for about 10-15 mins (also a very knowledgeable and pleasant person). Peter then sent me the details and pictures through email.

I must say over the almost 5 years of having my sub it continues to impress me. It’s still the best sub I have ever heard. I don’t know if the rattle due to part of these two movies or just the sub structure weakening over the YEARS of use/ABUSE that I have thrown at it. I guess I will find out with some more testing and implementing their suggestion. One thing that I am certain of is that I was always impressed by this company’s product and their customer service. Almost 5 years, later they have impressed me so much of their support/customer service, that I can honestly say…If all your competitors suddenly dropped their prices by HALF, I would still be a DIEHARD HSU customer.

Kudos HSU!! Awesome product…Terrific Customer Service…and Outstanding customer support.

PS…If some of your competitors were to drop their prices in Half or more, the price would still not matter as I believe some are very inferior to your products (too boomy). J

lradden August 26th, 2009 8:16 AM


Originally Posted by 95 Silver TA (Post 44935)
Almost 5 years, later they have impressed me so much of their support/customer service, that I can honestly say…If all your competitors suddenly dropped their prices by HALF, I would still be a DIEHARD HSU customer.

Amen to that. Hsu Research is such a first rate company, and Peter is so helpful that even if SVS or some other company offered me a FREE sub, I'd turn it down and pay full price for a sub from Hsu.

I've been a customer for several years now and I will NEVER buy a sub from any other company. There products and support are that good.

If the sub doesn't have a Hsu logo on it, it will never occupy a space in my home. Period.


sisu1a August 30th, 2009 7:59 AM

Hmm, have you pulled your driver out and hooked it to anything else? I have a 1220 that after a stint in storage came out and also had a strange rattly sound that was sorta intermittent.

I tracked it down to the driver itself, which appears to the eye and touch to be perfect, but I discovered the cone had migrated a fraction of a millimeter at the spider, causing it to make a clipping type rattle on lower freqs but had no problem above say 120Hz. I ran it full range and also filtered, using a very basey CD, and spoke with some Hsu folks about it.

Not much that can be done for my problem other than a driver replacement, so I got experimental. I found a spot on the spider that if I applied a slight tension, it worked OK. My (not so elegant-but completely effective) temp solution was to put a bungee cord on it, with one part laying across the spider, which seems to have given my driver the crutch it needed to get a new lease on life. I'm glad it's back in service, and it sounds as good as it ever did...

I suggest playing with your driver 'outside the box' to see if your spider has developed unequal tension or has migrated.


95 Silver TA August 31st, 2009 5:15 PM

Thanks for the reply....for now I am chalking it up to those two movies (I think) cuz we watched aleast 7 more movies on there 2 of which had some really good bass and I did not hear the rattle again. If it comes back and I can pin point it, then I will take apart the sub and give more of deeper look and try everyones recommendations.

95 Silver TA November 1st, 2009 5:00 AM

Thought I should provide and update....

I have watched a bunch more movies and it seems to only do it on certain movies (or at least I notice it) on those movies where the all the speakers are mainly quiet and theres bass going to the sub. Again, each time I put some weight on it, it either stops this completely or greatly minimizes the rattle. For the first few weeks, I placed a very big/wide 10 pound book on top of the sub box and that helped a LITTLE too.

I have spoken with HSU staff (as stated) and rather than try to sell me a new sub or sell me a new enclosure, they suggested a brace in the sub. I finally got around to doing this yesterday. I added the brace as suggested with Gorrilla glue. I was gonna let it dry for 24hrs but noticed after 5 hours that brace was rock solid in there so I let it sit for another 2hrs and watched our first movie on it. I did not hear a rattle but thats not to say that it completely worked because this rattle only seems to happen in about 10%-15% of the movies we watch. I will test it out for another week or two and post my results.

PS....when I pulled the woofer out, I could not believe the size and weight of this thing.

Also, HSU's staff is incredible, I cant believe the support I got from these guys 5 years later.

audiodelic November 1st, 2009 10:45 PM

I have a HSU VTF3MK3 with turbo. I am running it in deep extension mode with the turbo. I have similar problems as stated by 95 silver TA.
In dvd's there are scenes where there is very little sound in other speakers but the the sub suddenly comes on to give that deep bass effect to call attention to the scene this is where is hear a very bad sounding pop/rattle type sound.

What can be the problem ?

Pete_Hsu November 3rd, 2009 2:28 PM

Hi audiodelic,

How high is the volume knob on the subwoofer, and what is the subwoofer channel level set at on the receiver? Do you have crossover 'In' or 'Out' on the subwoofer amp? What crossover frequencies are set on the receiver, and is everything set to 'Small'? Are you using any auto-eq or auto-setup features on the receiver?


audiodelic November 3rd, 2009 9:21 PM

volume on subwoofer must be at 9 o clock position or little higher.
At the receiver subwoofer level is set at 0db ... Yamaha rx-v661.
crossover at subwoofer is bypassed and at receiver it is set @ 80hz all speakers are set to small.
No auto eq/auto setup features on the yamaha i have set all speakers using spl meter.
The noise that occurs from the subwoofer is quite loud and deep like a loud thud/distortion for a 1 second as the bass sequence starts suddenly in movie soundtracks.

PS - i misplaced my HSU Test CD anyway can i get a copy or you can upload somewhere and i download a copy from somewhere.

Pete_Hsu November 3rd, 2009 10:20 PM

So the crossover switch on the back of the subwoofer is set to 'Out', correct?

Have you tried removing the turbo (keeping both ports open, with bass extension switch on sub amp set to '2 port open' mode), and re-running that one particular sequence?

We used to have some mp3s out there, but looks like that link is no longer active.

Are you hearing this noise with only that one second sequence, or with a variety of different program material?


audiodelic November 4th, 2009 11:46 PM

Cross over is set out correct
No i have not tried unhooking the turbo as of yet.

This sound happens on other movies also. Although very specific it happens when other speakers are quite maybe some dialogue is running in center channel then there is that sudden bass it just pops so loudly scares me even and this pop is not there for entire sequence just in the start right when the bass sequence sound starts itll pop for a second as it receives the input then again it plays normal pumping out nice bass.

Ddavidson November 5th, 2009 7:21 AM

Use a test disk with all the different bass freq's. Once you find the "triggering freq", loop that freq and you will find it easier to locate the problem area, i.e. by touching the various parts of the sub till it stops or dampens the rattle (eg. touch parts like the port, amp, enclosure etc)


Pete_Hsu November 5th, 2009 10:27 AM

That is very strange behavior. Do you hear these noises when playing any 2 channel music (something that has significant mid and/or deep bass content)? Have you tried testing the driver by itself? Let me know if you need instructions on how to do that...

audiodelic November 5th, 2009 8:16 PM

No never heard these on 2 channel music ..... how much ever bass is present.
Happens only in dolby digital tracks especially when the scene is normally dialogue and then there is sudden bass as the scene dynamics change thats when it happens.

No i have not tried the testing the driver by itself. Please help on that.

95 Silver TA November 6th, 2009 9:03 AM

Popping sounds like its something different than the rattling I had. I know that some Receivers like my Onkyo 805 when set to source is set to bitstream has had issues with causing speakers to pop including the sub. Maybe your receiver has the same issue. My BR/DVD player is set to PCM not bitstream so I dont have that problem. could be worth a check.

Stiletto November 6th, 2009 12:53 PM

Wasn't that popping something that was fixed in a firmware update? I have a 705, and I remember a big stink about that and installing a firmware update. You might want to check AVS about it.


Originally Posted by 95 Silver TA (Post 48926)
Popping sounds like its something different than the rattling I had. I know that some Receivers like my Onkyo 805 when set to source is set to bitstream has had issues with causing speakers to pop including the sub. Maybe your receiver has the same issue. My BR/DVD player is set to PCM not bitstream so I dont have that problem. could be worth a check.

Pete_Hsu November 6th, 2009 3:00 PM

audiodelic, are you using an Onkyo receiver, and if so, what model?

audiodelic November 6th, 2009 6:18 PM

No i am using Yamaha RXV-661

Pete_Hsu November 7th, 2009 11:52 AM

I wonder if you are having any issues with the auto-on not waking up properly. Have you tried leaving the On/Off/Auto switch to 'On'? Note that power consumption is identical between 'On' and 'Auto' settings (the only difference is the LED control).

If that doesn't resolve things, then let me know, and I will give some instructions on testing the driver by itself.


sisu1a November 28th, 2009 8:43 PM


I just got another 1220HO. When I hooked it to my 500 watt amp, it too would make a distinct rattle:mad:, but only while really being pumped and only on certain (super) bassy selections of playback (whether movie or music).

I sighed and pulled out the driver and played with it some in free air, which led me to discover that on this one, the spider ring (outer ring the spider is glued to, which is in turn glued to the basket) had become partially unglued. Luckily this is an easy fix. First I broke the ring the rest of the way loose from the basket, then mixed up some high grade 5min epoxy (Gudgeon Bros G5 from West Marine, but I'm sure any would work) and glued it back, being very careful to keep it aligned properly. No more rattle- whatsoever.

The original glue appeared to be a polyeurethane type glue such as Gorilla, which had become brittle with age. 'Normal' playback did not reveal this issue, only really making it work brought it to light.

Again, I think you should pull your driver pump it out of it's enclosure. To do this, run extension wires from the amp to it's spades. Be vary careful not to short the wires together while it is playing heavy- best to electrical tape at least one spade plug to reduce the chance of contact while your strugling not to drop the very heavy driver while your inspecting it. It sounds to me like your spider ring may have also come partially unglued as well.


PS. the most punishing/revealing sub testing cd I have is called 'Antimatter vs. Antimatter' (Asphodel label). Much better than waiting for the rattle to strike at random...

95 Silver TA December 8th, 2009 8:06 AM

I've had about 3 weeks to test with about 20 movies and it seems that the brace mod with gorilla glue worked. I was on vacation for the week of Thanksgiving so I missed a week but I have not heard a rattle from the sub since the mod.

HSU did recommend to use 2 braces but I was able to use one due to incorrect measurements on the brace/pieces of wood that was cut. I also added some Gorilla glue to each corner that I could see inside the sub for added stability. So far the sub sounds as tight as it did the first week I owned it. If I ever notice any rattle in the future, I'll go back and add a second brace but wanted to post my results and thank the HSU staff again for helping me.

Again, I've estimated that I had about 3000 hours of hard use on this sub or about 2 hours of use EACH day for 4 plus years so most will not notice this as I assume most folks wont hit 3000 hours of hard use until about 10 years or more.


tman December 8th, 2009 9:43 AM

Out of curiousity, is sub expected to last or will need maintenance over time?
I do not push my sub to it's limits. I'm just curious after reading this thread about gorilla glue embrittling over time and needing to install the brace whether the enclosures are expected to last or degrade. I think of audio equipment as something that should last a long time if cared for (not 5 years). Is this failure expected over time or is it anomalous?

95 Silver TA December 20th, 2009 6:12 AM

Sub Brace Pics
1 Attachment(s)
I thought I should update this Thread with the pics.
Here a pic of the Sub Brace Pic. Its not of mine but of one that an HSU staff member sent me a few months ago. I have also included the instructions they sent at the time for the VTF3-MK2. Eventhough they recommend 2 braces, I put one in just because the other brace was cut too short and I did not have the time to get another piece of wood and re-cut (just being lazy on my end). I also added some Gorilla Glue to the inside corners of the top of the box (even though I did not notice any gaps as the email below stated). This little mod has worked really well and I have not heard a peep in terms of rattling or resonating since the mod.

Email instrx:
__________________________________________________ _________
Attached is a picture of the vertical wood brace that our technician recommended to you (note that the amp cutout is seen in the back of the picture).

The brace dimensions are: 18 and 11/16 " tall, 1 and 3/8" wide, and 3/4" deep.

We recommend using two braces, one as shown in the picture, and another brace that is a mirror image (next to the other port ) .

Place the brace 3" in front of the amplifier panel, so that the brace doesn't interfere with the PCB on the amplifier. Also make sure to remove any fiberglass in the top/bottom sections of the enclosure where the brace will be touching.

If you see any gaps in the brace that is holding the two ports, add some Gorilla glue ( all purpose type ) to seal the gaps.

subscession August 28th, 2014 8:33 AM


Could you provide dimensions for similar braces to use on the VTF-2 MK1? I'm pretty sure I'm having the same problem. The enclosure resonates when I run pink noise at reference level, but only in extension mode. Checked inside, no floating debris. Piece of carpet is under sub. Running the driver in the air produces no rattling. Ports are secure. Should make for a fun Labor Day weekend project.


Kevin_Hsu August 28th, 2014 10:31 AM

Hi David,

There actually is no internal bracing for the VTF-2 Mk1. What exactly is reference level for you? How far are you seated from the sub? Can you check the screws in the amplifier as well?


subscession August 28th, 2014 10:49 AM

Reference level for me on the sub is when it matches my other speakers to 75 db with SPL meter.

I've removed the amp and driver a few times, so I'm positive all the screws are tight.

Seated about 12 feet away.

Can't I install 2 pieces of wood like Pete suggested upthread?

subscession August 29th, 2014 4:43 PM

As an aside, I do have a minor confession: the amp was recently replaced with the DA SPA250. I would have shipped mine back for service, but the thought of living without my VTF for a week made my teeth hurt.

I have no doubt that the new amp is causing the rattling of the enclosure since it's 100 watts more than the OEM amp and has a 6db boost at 35hz, which I'm guessing is slightly off from the original bass extension specs.

But that said, if I run the driver up in the air with the amp removed and not touching the enclosure, there is no rattling sound, but if I lay the driver on the underside of the upside down enclosure, I can hear the exact same rattling sound.

I suspect it's something with which I should not concern myself since I only hit reference level with rumble tones for testing purposes.

But the million dollar question, what is causing that rattling sound? I thought of buying a voidless birch piece of wood to build an isolation platform instead of dishing $80 on the Subdude, which seems way overpriced.

Based on the OP, could it be voids in the MDF?

All times are GMT -8. The time now is 9:44 PM.

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.