Found a CL ad for Ascend 5.0 set and HSU MK3. Thoughts?

lsiberian

lsiberian

Audioholic Overlord
That's all you need? :rolleyes:
Make sure you have some extra money to replace the woofers you puncture with your screw driver. :eek:
And of course some health insurance to cover the ER visits. :D
 
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hizzaah

Full Audioholic
Now, you need a new TV.
exactly what I was thinking.. Something in the 60" range would suffice.

And of course some health insurance to cover the ER visits. :D
What type of mods are you talking about? I don't think I want to know what your screwdrivers are puncturing.......


I left my onkyo's hooked up for rear surround. My gf was like "these are big, but I wouldn't have bought them. You didn't even get all the speakers".. Just watch your show dear..
 
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hizzaah

Full Audioholic
First official complaint. Neighbor said I was rattling the pictures on his living room wall.. Honestly I thought I was listening at a more than respectable volume, although it is the HSU bass test cd that the sub came with.. I wish I didn't have a shared wall :p

Right now I have the woofer pointed directly in the room and the shared wall.. I guess I should turn it so it's facing into the cabinet? Any other suggestions?
 
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shadyJ

Speaker of the House
Staff member
Hizzah, do you have the option for near-field placement, ie using the sub in an end table role or behind the seat? This way you won't have to turn it up as much to get a nice bass sound. Also, what mode are you running the VTF3 in, max extension or max output? Are you using the turbo?

By the way, the direction its facing isn't going to make a difference.
 
ImcLoud

ImcLoud

Audioholic Ninja
This is the problem with apartments and home theaters, I hate to say it but I know if I was next door trying to sleep and someone was watching transformers for 3 hours I would have to kill someone...

I would try to move the sub rite by your seating and then maybe just use it when you are watching movies at a reasonable hour (unless your neighbor works nights) ... It kind of sucks the neighbor complained because now that is was brought to his attention it is going to be on their minds. When ever they here just a little bass they will be reminded of them complaining to you.... Kind of sucks...
 
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shadyJ

Speaker of the House
Staff member
Hizzah, the Hsu test CD, especially that first track, has some very strong 16 hz pipe organ notes in it. It won't sound loud because human hearing isn't very sensitive at that low of a frequency, but it can still be a strong sound in how it affects stuff around it. If you need to reduce the VTF3's ability to play deep bass entirely, one trick is to plug both ports. If you have the foam port plug, use it in one port, and then take a towel, roll it up, and fit it tightly in the other port so that no air can escape. This will dramatically reduce the subs output from the high 30 hz region on down. On the positive side, this might tighten up the bass a bit as there will be no port induced overhang or group delay.
 
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hizzaah

Full Audioholic
Hizzah, do you have the option for near-field placement, ie using the sub in an end table role or behind the seat? This way you won't have to turn it up as much to get a nice bass sound. Also, what mode are you running the VTF3 in, max extension or max output? Are you using the turbo?

By the way, the direction its facing isn't going to make a difference.
I'd need to buy a longer sub cable to move it by my seating. Our current seating is up against the shared wall though, so I'm not sure how much that'll help.

I believe the switch on the back says either

1 Port Open or w/ Turbo 18hz
2 Ports Open or w/o Turbo 25hz

And I have it set on the second which I assume is max output because I haven't put the turbo on yet.

This is the problem with apartments and home theaters, I hate to say it but I know if I was next door trying to sleep and someone was watching transformers for 3 hours I would have to kill someone...

I would try to move the sub rite by your seating and then maybe just use it when you are watching movies at a reasonable hour (unless your neighbor works nights) ... It kind of sucks the neighbor complained because now that is was brought to his attention it is going to be on their minds. When ever they here just a little bass they will be reminded of them complaining to you.... Kind of sucks...
Yeah, and I completely understand it too. I had to put up with a dorm neighbor my first year who put his sub right at the head of my bed after I asked him to turn his music down one night.. Many a nights were spent pounding on the wall or socking the RA on them..

My neighbor is actually a cool guy. We hang out with him in back yard, light a fire, drink, etc. all the time.

Hizzah, the Hsu test CD, especially that first track, has some very strong 16 hz pipe organ notes in it. It won't sound loud because human hearing isn't very sensitive at that low of a frequency, but it can still be a strong sound in how it affects stuff around it. If you need to reduce the VTF3's ability to play deep bass entirely, one trick is to plug both ports. If you have the foam port plug, use it in one port, and then take a towel, roll it up, and fit it tightly in the other port so that no air can escape. This will dramatically reduce the subs output from the high 30 hz region on down. On the positive side, this might tighten up the bass a bit as there will be no port induced overhang or group delay.
The guy said he never had a foam plug for the sub, so no, I didn't get one. I'll find some towels to try out though. Could I put the turbo on and them use the towels? Honestly, I don't have anywhere to really store the turbo so I'm going to put it on to get it out of the way lol

Plugging the ports won't kill the sub? I need to read up on subs, I just assumed they needed that air internally to function properly.
 
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shadyJ

Speaker of the House
Staff member
If you sit against the shared wall, than maybe it won't help that much if you place the sub next to you.

Don't try to use the turbo with the ports blocked, lol. The turbo is merely an extension of the ports, so it won't do any good if the ports are negated. The way subwoofer ports act is like the top of a bottle when you blow over it, this is called a helmholtz resonator. It produces most of the low frequency output of the subwoofer. The driver itself can not do anywhere near that low frequency output. The width and length of the ports determine the tuning point of the subwoofer. A long narrow port will produce deeper frequencies than a wide port. When the port is wider, you get a higher tuning point but more output. With the VTF3, you get two large ports that can act as one wide port (for the 25 hz tuning point) or just use a single port for deep bass at the expense of some output from roughly 25 to 40 hz. The Turbo basically doubles the length of both ports, so you get the deep tuning of the single port mode and the big output of dual port mode. In practice though, it had questionable results for the mk3, and, like I said, it looks like it was really meant for the now discontinued VTF3 HO which was a more powerful sub.

If I were you, I would try different things, like near-field placement and plugging both ports, and ask your neighbor how much effect he is getting while running some frequency sweeps like some of these.
 
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FirstReflection

AV Rant Co-Host
ShadyJ won't like what I'm about to say, because for some reason, he doesn't believe that putting vibrating objects on some sort of cushion will reduce the transmission of those vibrations into the surface on which the vibrating object is sitting.

But if you aren't crazy like ShadyJ is, you should be pretty familiar with the idea of putting some sort of cushion under a vibrating object in order to damp its vibrations ;)

A great deal of the physical shaking in your neighbor's apartment is due to having the "feet" of the subwoofer in direct contact with your floor. Those "feet" on the bottom of the subwoofer make the transfer of the subwoofer's vibrations into the floor worse. It's all about pounds per square inch. The weight of the subwoofer doesn't change, but with the "feet" in place, you've got far fewer square inches of surface area in contact with the floor. End result is very high pounds per square inch. And all of the physical vibrations of the subwoofer get transmitted directly into the floor. The floor is connected to the walls. The walls are connected to the ceiling. So before you know it, those vibrations are quickly travelling throughout the entire structure of your apartment building!

While it won't solve ALL of your problems (there's still airborne sound to consider, of course ;) ) having some sort of damping in between the bottom of your subwoofer and the floor will help. All you're after is a shock absorber. Stop the vibrations of the subwoofer from reaching the floor. I've no idea why, but ShadyJ swears this is "snake oil" and "BS". Meanwhile, every other person on Earth understands this idea pretty easily. I mean, put your phone on vibrate and sit it directly on a table top. Phone rings and the table buzzes like crazy. Put a pillow under the phone, and when it vibrates...WAY less noise, right? I've no idea why ShadyJ thinks that's "snake oil", but it seems pretty self-explanatory to me.

Now, I'm giving ShadyJ a hard time here, and I want to give him the benefit of the doubt. He's mostly just railed against "subwoofer platforms" or "decoupling risers", such as the Auralex GRAMMA. Those are the devices he's called "snake oil" and "BS".

Now, if his problem is simply that he thinks the $50 asking price is too high, I've no beef with that. The Auralex platforms are nothing more than a piece of MDF wrapped in carpet with some foam glued to the bottom. You can certainly build something very similar yourself for less money than $50. Or you could use something as simple as some blankets to act as a damper between the bottom of your subwoofer and the floor!

But ShadyJ has flat out said that he doesn't believe damping platforms do ANYTHING because he hasn't seen the objective measurements to prove it. And, apparently, having windows and picture frames shake and rattle when there is no damping platform in place vs. having those same windows and picture frames NOT shake and rattler - or at least shake and rattle much less - is not proof enough. We're all being fooled by the "snake oil" according to him. But I dunno. It's been pretty cut and dry for me. Window rattles when the sub's sitting directly on the floor. Window doesn't rattle when I have a damping platform under the subwoofer. And funny thing is, every single person who's ever been to my apartment experiences the exact same thing. I guess we're all delusional. Unless, of course, there were 3rd party measurements printed by someone other than me. Then we could believe what our senses of sight, hearing and touch tell us is obvious. But until then, according to ShadyJ, we can never know. Apparently the window and picture frames no longer rattling is all placebo effect. It's awfully strange that my cat jumps when the window rattles, but doesn't jump when the window doesn't rattle though. I guess he's subject to the placebo effect, too! Fascinating.

lol

Anyways, to be clear, I'm saying this light-heartedly. But I've gotta give ShadyJ a hard time about this. Calling the entire notion of damping vibrations "snake oil" just isn't something I can let slide by. It's just plain bad advice to tell people to NOT damp in between the bottom of their subwoofer and the floor when that is such an easy, cheap and effective solution to so many issues with bothering the neighbors or other people in different rooms of the house!

And I mean, here's the final word - it's a pretty darn easy and cheap experiment to try for yourself! Fold up a few thick blankets. Put them under your subwoofer. Play the subwoofer. And talk to your neighbor to see if there's any improvement! If there is, then great! You know that damping will help in your case, and you can make or buy something a little more visually attractive and physically stable than folded up blankets ;) If it doesn't help, then so what? Did it kill you? According to ShadyJ, you shouldn't even try. Apparently it will harm you in some way to perform this experiment for yourself. I don't get it...

Anywho, give damping a try. Heck, let's say ShadyJ is right. Let's say damping is all "snake oil" and "BS". Let's say it's all placebo effect. If your neighbor and you both stop hearing annoying rattles, and he stops complaining, and you can enjoy your subwoofer without bothering your neighbor, does it really matter? Seems like it would still be a solution to me!

But, of course, it isn't just placebo, and it isn't "snake oil" or "BS". We're all very familiar with how damping vibrations works. So that's all a product like the Auralex GRAMMA risers is - it's a damping platform - a way to stop the vibrations of the subwoofer from being transmitted into the floor. You can hate the price - that's totally up to you. But you can't hate the simple idea of damping. It's a pretty basic and well understood concept ;)
 
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shadyJ

Speaker of the House
Staff member
Did someone say bass isolation pad!? Gentlemen! Once more into the breach!

Seriously though, if you give credence to the idea that your sub's enclosure may be vibrating the floor, try First Reflection's suggestion of putting some folded up blankets beneath the feet. I don't believe it will help, but it doesn't cost anything except for the time it takes to do it. For the record, what is causing the vibrations is high amplitude pressure waves hitting every surface around you from 16 to 80 times a second at a speed of 344 meters per second, which are emitted from the woofer and ports, so the air itself is vibrating- this is bound to affect loose stuff in your environment. Any vibration added by your sub's cabinet is negligible in comparison, especially when the sub is as heavily built and braced as your VTF3.
 
Alex2507

Alex2507

Audioholic Slumlord
Get the Gramma or the Subdude, whichever fits best. You won't be sorry.

Try to start your movies by 6 or 7 (that's movie hour) so you can be done by 8 or 9.

My subs are plugged into a switched outlet. The switch is lit so I can see if it's on or off.

Lot's of people here are all for decoupling. Get some of those MoPads for your center too.
 
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FirstReflection

AV Rant Co-Host
Thanks for being a good sport, ShadyJ :) I do mean that sincerely.

Truly, putting a damper of some kind under your subwoofer is an easy, cheap experiment. You don't have to believe ShadyJ or myself, or anyone else on either side of this argument. You can easily try it yourself for essentially zero money (like ShadyJ says, just some of your time) :)

As to why physically damping the connection would do anything at all vs. just the pressure waves in the air - there was actually a great episode of Mythbusters that did a pretty good job of explaining the phenomenon. In laymen's terms, waves don't transistion particularly well between different mediums, or even similar mediums of differing densities. When a wave reaches the border between two different mediums, most of the energy gets reflected back. In the Mythbusters episode, they were demonstrating how you could survive an underwater mine blast by laying as flat as possible on the surface of the water. If you were to float vertical in the water, the shockwave would hit the portion of your body that is submerged and potentially kill you. But if you are laying flat on the water's surface, most of the energy of the shockwave gets reflected back down into the water when the shockwave reaches the border between the water and the air. They even talked about how they expected the pressure sensors to detect higher pressure on the dummy's body when it was laying flat because there would be more surface area exposed to the pressure wave. Instead, it was the exact opposite! Science!!! :D

Turns out, waves don't like to transition into different mediums. This is actually the basis for decoupling - ie. physically separating two objects. There can still be air between the two moving objects. But the air is a pretty good cushion or spring, it turns out. More than that though, it is this tendancy for waves to avoid transitioning between mediums, and to reflect whenever they reach a border between two mediums instead.

Another great real world example is putting your ear to a train track. If you've ever done this - or even just heard tales of other people doing it - you'll know that when you put your ear on the train track, you can hear a train coming from miles and miles away! Stand up and just listen with your ears in the air, and you can't hear the train at all.

The train is still making just as much noise. The train is still vibrating just as much. The tracks are still vibrating just as much. But sound travels at different speeds, and loses energy over distance at different rates through different mediums! Turns out, air doesn't carry sound waves as fast or as far with as much energy as denser mediums. We can hear "better" underwater - as in, we can hear quieter sounds from farther away underwater than in the air. And sound waves travel even faster and stronger through solids that aren't inert.

But when those sound waves try to transition into the air, the energy gets reflected back at the border. Whale calls can be heard from miles away when you're under water. But above the water, we don't hear them. It's actually pretty neat when you think about it ;)

So that's what's going on with your subwoofer. Like the train on the track, the vibrations that are travelling via the solid structure of your apartment building travel fast and strong. Meanwhile, the soundwaves that travel through the air hit the wall, floor or ceiling - a different medium - and mostly reflect back into the room. Decouple or damp the connection between the bottom of the subwoofer and the floor, and you greatly reduce the transmission of energy from one room to another.

That's the science explanation. In practice, the reason why it works isn't terribly important. All that really matters is whether it stops your neighbor from complaining! But just like the Mythbusters, you can try your own experiment in order to find out! The results might surprise you the way laying flat on the water surprised them. But it works. The results are obvious. And putting a couple folded blankets under your subwoofer while it plays for a few minutes is a pretty cheap and easy experiment.

Good luck! :)
 
its phillip

its phillip

Audioholic Ninja
I've noticed absolutely no benefit from my great gramma. The mopads have helped though.
 
lsiberian

lsiberian

Audioholic Overlord
folded up blankets beneath the feet.
Oh my I never knew. :eek:

Sound passed from the box to the structure is reduced by using a decoupler. This is why they put a decoupler beneath heavy machinery in factories.

Of course things will still rattle, but sound in other rooms is reduced and it's not as pronounced. Of course if your house is well insulated and has thick carpet then you'd not see as big a benefit.

Significant bracing is not needed inside a subwoofer because the sound is too low to vibrate the sides of the box.
 
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hizzaah

Full Audioholic
So I went ahead and plugged both ports with rolled up towels, and put the sub on top of one of those UHaul utility blanket (folded to be ~4 inches thick). It's hard to say if it'll make a difference for my neighbor or not as he isn't home currently, but the bass sounds tighter to me now.
 
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shadyJ

Speaker of the House
Staff member
Here is a thought experiment for all the advocates of bass isolation pads. Take the air resistance of the subwoofer's moving cone, and translate that into moving mass instead. How much weight would that be? I dunno, but I am sure there is a formula in physics that would tell us. You can get an idea of this air resistance by holding a stiff 12" diameter cone and zig-zagging it back and forth in the air at the same frequencies and amplitudes your subwoofer normally oscillates it's cone at- typically the oscillation is so small you can not even see the cone move unless you are really blazing it or trying to play deep frequencies. Anyway, add that mass onto the mass of stuff that is already moving inside a sub, ie the cone and voice coil (neither weighs a lot). So how much weight do you have swinging back and forth in a heavily built enclosure which has four points of solid contact on the floor? Enough to cause stuff in adjacent rooms to vibrate? In my opinion, no way.

You are bumping air into things via longitudinal waves. The motor in the subwoofer isn't shifting so much mass that it's affecting stuff by it's contact with the floor.
 
Alex2507

Alex2507

Audioholic Slumlord
Here is a thought experiment for all the advocates of bass isolation pads. Take the air resistance of the subwoofer's moving cone, and translate that into moving mass instead. How much weight would that be? I dunno, but I am sure there is a formula in physics that would tell us. You can get an idea of this air resistance by holding a stiff 12" diameter cone and zig-zagging it back and forth in the air at the same frequencies and amplitudes your subwoofer normally oscillates it's cone at- typically the oscillation is so small you can not even see the cone move unless you are really blazing it or trying to play deep frequencies. Anyway, add that mass onto the mass of stuff that is already moving inside a sub, ie the cone and voice coil (neither weighs a lot). So how much weight do you have swinging back and forth in a heavily built enclosure which has four points of solid contact on the floor? Enough to cause stuff in adjacent rooms to vibrate? In my opinion, no way.

You are bumping air into things via longitudinal waves. The motor in the subwoofer isn't shifting so much mass that it's affecting stuff by it's contact with the floor.
In your case I recommend the Subdude.
 
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hizzaah

Full Audioholic
Well I'm learning a fair amount more about the physics of wave travel than I expected to in this thread. If I had the money I'd build out a second back wall or something, but alas, I do not. These speakers have decent enough bass output so I'll use them in the evenings and use the sub during the day when the neighbors are gone.

So can someone explain a few of the switches on the back of this thing?

- Phase switch can be 0 or 180 degrees
- I've set Bass Extension up to "1 port open or w/ turbo 18Hz" which I assume implys extension instead of the other option of "2 ports open w/ no turbo" because I assumed that was max output mode?
- I put the crossover knob at 90 (highest)
- There's a switch for crossover to be out or in. Which do I want?

It appears the fella broke off the Power switch. It was set to on and I tried to move it to auto but it's real twitchy. Do i need to contact HSU to replace this?

I unplugged it and checked the fuse. It looks good except for the fact the there's some kinda glue or something smattered around on it and in the fuse hole. Not sure what the deal with that is. Something to worry about?
 
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shadyJ

Speaker of the House
Staff member
Well I'm learning a fair amount more about the physics of wave travel than I expected to in this thread. If I had the money I'd build out a second back wall or something, but alas, I do not. These speakers have decent enough bass output so I'll use them in the evenings and use the sub during the day when the neighbors are gone.

So can someone explain a few of the switches on the back of this thing?

- Phase switch can be 0 or 180 degrees
- I've set Bass Extension up to "1 port open or w/ turbo 18Hz" which I assume implys extension instead of the other option of "2 ports open w/ no turbo" because I assumed that was max output mode?
- I put the crossover knob at 90 (highest)
- There's a switch for crossover to be out or in. Which do I want?

It appears the fella broke off the Power switch. It was set to on and I tried to move it to auto but it's real twitchy. Do i need to contact HSU to replace this?

I unplugged it and checked the fuse. It looks good except for the fact the there's some kinda glue or something smattered around on it and in the fuse hole. Not sure what the deal with that is. Something to worry about?
It doesn't matter where you set the phase switch if you are using the Denon's Audyssey. Audyssey will set that up for you, so you might as well have it set to zero.

If you are plugging both ports, it doesn't matter too much which mode you set the sub in. I would set it to 2 ports open mode in that configuration, since you are not going to get deep bass either way, so there isn't any point in having the sub try to dig low, it will just be pushing itself for no reason.

As far as the power switch goes, just leave it on. Hsu only provides an auto mode because it makes people feel better about having it. In reality, the sub does not consume less power when in standby on auto. It is a pointless feature that is only there due to customer demand, but it serves no real purpose.

For the crossover, set it to 'out', and run Audyssey. Let the Denon take care of the crossover. It sounds like you haven't run Audyssey yet, it will benefit you to do so. Hopefully the guy who sold you the receiver remembered to give you the microphone that came with it.

I wouldn't worry about glue around the fuse.
 
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