# My HSU is... dying???? Any thoughts?



## Todd Anderson (Jul 24, 2009)

So my new HSU VTF-2 MK4 sub seems to be having some troubles. It's about 4 months old. I noticed, the other day while we were watching a movie that the bass sounded thin... but with all of the other sound from the movie in the room (and the bass shakers) it was a little difficult to tell...

Just now I got out the HSU calibration CD that has test tones. Popped it in... really disappointed.

First off, I checked all of the settings on the plate amp and double checked the HSU manual. They all match up and check out ok.

When the test tones play... following will happen (randomly)

1) tone plays fine

2) tone plays but at a diminished volume and there is this weird scratching/someone is crumbling up paper sound... kind of static-like but very random in presentation.

3) tone starts playing... then just cuts out and there is nothing.


I checked my LFE cable. It's securely fastened to the plate amp. Connections to my AVR are also secure.

Literally, nothing has changed in terms of cable routing/hook-up in years.


So I am really frustrated. :hissyfit: A little bummed out.:rolleyesno: And concerned :sweat:

I called HSU. Got a message machine. I'm hoping they return my call... but in the mean time all I can think of is the pain this is going to be trying to ship this beast back to HSU. It's going to cost a fortune.

Any thoughts, anyone?

T


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## theJman (Mar 3, 2012)

Are you adverse to turning a few screws? If not, perhaps they can just send you a new amp. More than likely that's the issue, and if you're OK with replacing it yourself that may be the quickest/easiest fix.


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## hjones4841 (Jan 21, 2009)

Sounds like the amp. Agree that the amp is the only thing you will have to ship. Hsu has great customer service and they will take care of the problem for you.


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## Todd Anderson (Jul 24, 2009)

Thanks guys...

You think the amp would make that crackling windy sound?

So odd...


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## hjones4841 (Jan 21, 2009)

A bad electrolytic capacitor certainly can make a cracking, static sound. Could make kinda whooshing sound also, between cracks if that it what you are hearing.


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## Dale Rasco (Apr 11, 2009)

I know you verified the cable was secured but did you try replacing it? It's the cheapest and easiest option to check.


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## Mike P. (Apr 6, 2007)

I had the same symptoms on a Pioneer sub, the issue was a bad gain control. Turn the knob back and forth to see if it makes any difference.


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## Todd Anderson (Jul 24, 2009)

Dale Rasco said:


> I know you verified the cable was secured but did you try replacing it? It's the cheapest and easiest option to check.


No, I didn't try replacing it. I will though.


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## Todd Anderson (Jul 24, 2009)

What's strange is that it's intermittent. There are periods where it works fine. Then it dives into these bizarre patterns.


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## hjones4841 (Jan 21, 2009)

That still can be a capacitor in the audio circuitry - actually, typical behavior for the noise to come and go. Get with Hsu and get the amp swapped. Since you have had it for a short while the warranty should cover the repairs. You may have to pay for one-way shipping, tho.


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## lcaillo (May 2, 2006)

27dnast said:


> Thanks guys...
> 
> You think the amp would make that crackling windy sound?
> 
> So odd...


More likely than the driver. Could be a bad solder connection or a cap going bad. Could be other things as well, but probably no need to send the whole thing in. Have you heard from them yet?


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## Todd Anderson (Jul 24, 2009)

I did...strangely at 11:30PM last night! ;-)

I guess they are at the RMAF.

The want to me connect a cd player directly to the sub with a new cable... see if it reproduces the problem. If it comes back, they want me to connect the woofer directly to speaker wire from my mains. That will test to see if the woofer is the cause. If not, it's the amp.

I'll have some time today to run the tests.

Thanks for all of your input, guys!!:T


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## wingnut4772 (Jun 11, 2012)

Write Hsu. Their customer service is pretty good. Their subs tend to be pretty fragile. I have had to replace an amp and 2 drivers on my ULS 15s in the past year.


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## Todd Anderson (Jul 24, 2009)

Well, I sat down today to run through HSU's tests. To start, I put a test tones cd in my BD player... wanted to run through some test tones to recreate the problem. I was then going to attach a CD player directly to my sub (to eliminate all of my other equipment) and run through the same tones.

I'm sure you can guess where this is going...:scratch:

I sat in my HT for 20+ minutes running tones off my BD player and couldn't get the problem to replicate.

Then, very briefly for about 3 seconds I heard some scratching/whispy sounds during one of the tones... but couldn't get it to do it again. Part of me is glad... the other part frustrated!!!

So, I began to fool around with my whole system, checking connections - again - and I found something curious... and then something happened.

The left input plug on the back of my Feedback Destroyer is unusually loose... not the plug connection... but it almost feels like input (Receptor??) is loose internally. Now, I do run two subs. Both are connected to the BFD using the right and left channels. The loose input is on the left channel... the HSU sub in question is on the right channel (note, during my testing my other sub was off... once heard the noise - briefly - today I turned the second sub to see if the same issue was going on with the second sub, too (but the issue never happened again).

So I popped in BD to listen to run a test with a movie... second sub wouldn't work (the LED chain associated with the output level for the left channel on the BFD was dead). So, I went behind my equipment cubby, opened it up, jiggled the connection... voila! The light chain illuminated and the sub started working again.

So.


I'm wondering if all of this is due to my BFD. When I have more time tomorrow, I'm going to hook the cd player directly to the sub and run through the test tones.

Very curious, tho...:scratch:


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## hjones4841 (Jan 21, 2009)

Yeah, bypass the BFD completely (take it out of the circuit, not just bypass with the switch on the front) before doing anything else.


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