Brand new VTF2MkIII, rattle ...

[JustPete]

Hi all... First post. Sorry it has to be a problem one ... I'm assuming the good and helpful people of HSU research read this forum and give suggestions.

I just purchased a VTF2MkIII in walnut. Let me first say, over all I love it. Very musical quality to it of all my subs it's equal to or surpasses their tone with a couple exceptions and for a lot less money...

Just to let everyone know, I'm not some novice or kid with a new boom box. I've been both a musician and audiophile for well over 30 years and I have many subs throughout my home including this one. (Sunfire Signature EQ, SVS PB2 Ultra and an Velodyne Micro Vee to name a few) I bought this sub because I've long wanted to try HSU and I'd just completed a new room whose theme was a lot of walnut colored woodwork and the VTF2 looked like it would fit in perfectly (Which I'm happy to say it does)

So back on to my problem ... I've had this sub now approximately 3 weeks

The sub is set up at the rear corner of the room about 5ft behind the main listening area. Volume has never been past the 10 o'clock mark. It's set up to play below 80 hz combined with some bookshelve mounted on the front wall corners of my room. The crossover is controlled via a Parasound preamp with crossover control for the sub(s) and the crossover on the VTF is defeated. The sound blends beautifully and I'm very happy with the musicality of this sub. It's very musical, tight bass on par with my others in that department. I set it up in maximum extension mode.

The purpose of this sub is simply to fill the lower octaves of music. There is no video system whatsoever hooked up to this system. It's dedicated to playing stereo music at moderate volume only and has never been pushed to see what it can do. I already experienced all the bass I need to as a musician with both guitar and bass amps, and my SVS or Sunfire can already crack walls. That's not what this sub was for.

The first thing I noticed was massive port chuffing with the demo cd played as suggested. No big deal. Those are some pretty low tones. Controlling the chuffing with them would be an amazing feet with tubes.

The real problem is an annoying buzzz/rattle. The first thing I did after setting it up, was to control all the rattling in the room. I literally took apart the Ben Franklin stove in the room to fix a rattle in it at sub 30hz bass frequencies from a stand up/contrabass . The room is almost entirely wood, including the tongue and groove ceiling, so rattles were few. 3 large and heavily padded sofas and some end tables are all that's in the room on carpeted floor.

After finding every rattle and eliminating them, I've been just enjoying the music. I played the sub low level to burn in the amp for literally a week straight (which I do with all musical gear) On to the problem.

On certain low frequencies, especially with contrabass there was a persistent buzzing sound. I tried in vain to find it coming from the wall, a cord or interlink buzzing or some other such source.

Finally, I zeroed in on the sub itself. I thought maybe it's power cord or the interconnect were the source. Nope. I'm using a very heavy interconnect, so getting that to buzz, especially at low/moderate volume would have been surprising.

It was coming from the sub itself. So I then tipped the sub back and put my ear to the open port. It's coming from inside the sub. Now ... before anyone tells me about kids and sticking stuff in holes. That is definately not the case. I have no small kids. My youngest is 17.

Either the amp, or a wire, or something loose inside the sub, buzzes at low frequencies which are amplified to be very audible through the port.

So ... suggestions? I don't want to send it back if I don't have too and I'm assuming others have had a similar experience.

My minds eye tells me this is a wire buzzing against the side of the cabinet or something of that sort. But it MAY be something internal to the amp, or poorly glued bracing.

Before I send it back or open it up, suggestions?

Thanks all...

Pete

[Pete_Hsu]

Hi Pete,

Thank you for all the kind words about the sound quality, we really appreciate it! Now, with respect to the buzzing, try playing tracks 9 through 16 on the test tone CD that came with the subwoofer. Do you hear the noise with all tones, or just one or two tones in particular? Also, may I ask what settings you have on the back of the VTF subwoofer, and what settings you have on the receiver (for crossover and channel levels for each speaker and subwoofer)? Finally, are you using the subwoofer with spiked feet on any hard flooring surface?

Thanks so much

Sincerely,

[JustPete]

Thanks for the reply Pete ...

Using the test cd the rattle happens with tones on track 13,14&15. 14 the most, which is why I suspect it's something like a wire inside that vibrates at that frequency.

I made sure the high level inputs are screwed down snug, so it's not them.

My settings/setup are as follows:

RCA interconnects used in stereo to preamp sub out. The PREAMP sub out is set at 80hz and below.
Volume is on 10o'clock marker.
Phase is switched to 180 which works best in this set up.
Bass extension switch is in the UP position
Crossover though irrelevant as set up is at the 90hz mark.
Crossover switch is set to OUT.
Power set to Auto.
Power Cord runs to a TrippLite Power Conditioner/Surge Protection/Multi-plug Center.

The pre-amp is set to give the sub 80hz and below frequencies. All other tone controls are defeated in favor of direct through to the sub and speakers to a separate 2 channel 220w Kenwood M2A Dynamic Linear Drive Amp that feeds the bookshelf speakers only.

The spikes are installed and the room is carpeted with an 8lb pad as well.

Spikes are all tight.

Like I said, the rattle can be heard inside the open port. I'm even suspecting the port itself may be the source of the rattle.

Thanks

Pete

[JustPete]

Any suggestions? ...

[Pete_Hsu]

Thanks for the info Pete.

Are you feeding both the left and right rca inputs from a single rca subwoofer pre-out on your processor? Does your processor let you adjust subwoofer channel level, and if so, how high is the subwoofer channel?

Try flipping the bass extension switch to the down position. Second, try putting your hand into the open port, and press down on the port with your amp. Third, try pressing down on the top of the enclosure. Play test tones 13 through 15. Does the noise reduce under any of these circumstances?

Thx

Sincerely,

[JustPete]

Are you feeding both the left and right rca inputs from a single rca subwoofer pre-out on your processor?
It's a stereo interconnect from a stereo dedicated output from the preamp to the stereo input on the sub, set to only send frequencies from 80hz and lower.

Does your processor let you adjust subwoofer channel level, and if so, how high is the subwoofer channel?

Yes but it's set to 0db as are all tone controls.

Try flipping the bass extension switch to the down position. Second, try putting your hand into the open port, and press down on the port with your amp. Third, try pressing down on the top of the enclosure. Play test tones 13 through 15. Does the noise reduce under any of these circumstances?


The switch did nothing. Placing my hand into the open port did nothing, but, putting my fingers in, with thumb on the top of the enclosed and gently squeezing it amplified the vibration considerably. Pushing down on the top center of the cabinet seemed to produce different results. Sometimes making the vibration louder and sometimes making it disappear.

IMO the port is the problem. It's loose or not completely supported inside. Or possibly a wire was routed across it.

What do you think and what should I do. I don't want to open up the sub without being given a green light to do so.

Thanks.

[Pete_Hsu]

Take the subwoofer and flip it upside down. Press your finger gently around the driver's dustcap, moving in a circular motion across the whole circumference of the dustcap. Do the same around the driver's rubber surround, in between the surround and the gasket. Make sure to blow off any small particles that may have accumulated on the woofer cone.

What is interesting is that you can only hear the buzzing centered near 50Hz. If the port was the problem, then I would expect the noise to be audible with lower frequency tones. Do you hear the noise with the volume knob on the sub at, say, 9 o'clock? Do you hear the noise when standing in front of the subwoofer (with ports firing backwards)? Try putting masking tape around the circumference of each port flare (at the point where the circular cutout is made on the enclosure to house each port). Does that reduce the noise at all?

If none of that does the trick, then absolutely you have our permission to check inside the enclosure. Unplug everything from the back of the amplifier, remove the 12 perimeter screws along the four outer edges of the amp, pull the amp out a bit (you can rest it inside the enclosure if you wish), and look inside for any loose items.

Thanks

[JustPete]

Take the subwoofer and flip it upside down. Press your finger gently around the driver's dustcap, moving in a circular motion across the whole circumference of the dustcap. Do the same around the driver's rubber surround, in between the surround and the gasket. Make sure to blow off any small particles that may have accumulated on the woofer cone.

What is interesting is that you can only hear the buzzing centered near 50Hz. If the port was the problem, then I would expect the noise to be audible with lower frequency tones. Do you hear the noise with the volume knob on the sub at, say, 9 o'clock? Do you hear the noise when standing in front of the subwoofer (with ports firing backwards)? Try putting masking tape around the circumference of each port flare (at the point where the circular cutout is made on the enclosure to house each port). Does that reduce the noise at all?

If none of that does the trick, then absolutely you have our permission to check inside the enclosure. Unplug everything from the back of the amplifier, remove the 12 perimeter screws along the four outer edges of the amp, pull the amp out a bit (you can rest it inside the enclosure if you wish), and look inside for any loose items.

Thanks

It doesn't do it at lower volumes. Only at volumes I would say are approaching reference levels and I assume higher. (75-100db)

The noise is apparent from anywhere in the room. Listening to it, it definitely has the sound/tone of something like plastic rattling/buzzing. I think it takes a certain level to generate enough resonant pressure same as at lower levels my Ben Franklin was fine, but the minute it got turned up to a moderate level is howled with vibration.

With tape around the circumference of the port, are you thinking maybe it's an air leak? Like I said before, when I put my hand in the port and squeezed with my thumb on the top of the cabinet, it got MUCH louder. It's definitely not the driver.

I believe the rattle is also present at some of the lower tones as well as the lower registers of a contrabass, but I couldn't stand listening to it at that level, with a single dedicated tone and it was shaking the entire audio rack making zeroing in on one rattle impossible. Between that and the very audible port chuffing there was no way I was going to hear the rattle. During the dynamics and control of music, it's much more apparent and more easily heard.

So long as it's ok and I have you permission, I'll try what you suggested tomorrow and if that doesn't help, open it up and see what's what.

[Pete_Hsu]

In addition to the suggestions I made above, try blocking off the open port. Place a rolled up towel inside the open port, to see how things sound when the enclosure is sealed. Note that when pressing on both the port and the enclosure, hard to tell if it is related to an issue with a port-related resonance or enclosure resonance. Sealing the ports will help to make the issue more easily identifiable. Please inspect the driver too as I described just to be safe.

[JustPete]

Will do

Thanks Pete!

[JustPete]

OK ... I opened up the cabinet by removing the "amp" plate.

I thought I'd find a clamp on the tubes loose or a wire across a tube as the culprit. Not the case.

I did find 2 problems though and a couple things that surprised me.

Problems
1. The tubes where they mount on the cabinet brace is most definitely the source of rattling. Even though they're hot glued on one side, they're loose. If I might offer a suggestion how to never have this happen again. Putting foam on the MDF, rather than it being directly on the tube, would have prevented this by maintaining constant pressure on the tube. I'm going to have to remove the bead of glue that's on the tube and re glue them with a shim for some pressure. That's why when I would squeeze up on the port, it magnified the rattle significantly.

2. The wire from the "amp" though a loop was tied in it, and some light batting material was put around it, was resting on the bottom of the cabinet with a down firing speaker. I don't know for sure the wire was making any additional noise, but no doubt it possibly could, so I will wrap that with something slightly more padded and hope there's no problem.

Surprises
1. I could have sworn reviews I read, referenced for this sub show the tubes to both be bent 90degrees towards the bottom, but these are 2 straight tubes.

2. There must be some real electronic wizardry going on with the "amp" because I've never seen one so pathetic/puny. There's not much more going on here than the little cigarette pack sized 50w stereo amps I remember having in my car as a kid. Is this what they call an "amp" nowadays??? Do these "amps" hold up? This thing can't possibly be capable of any peaks over 300watts, but if I recall I read temporary bursts of power much greater.

Bottom line is the proof is in the puddin', and my opinion of the sound quality and cabinet look, rattles aside, haven't changed.

The "amp" is a bit of a surprise I must say, but... I'm no electronics engineer so what do I know. It's sure not the Sunfire Amp in my Sig Sub, but I didn't expect it to be.

At any rate, I believe with a little bit of fiddling I'll have the rattle fixed ... unless that's not what you want me to do ...

Do I attempt to glue the tubes in better?

[pontgranprix]

This link shows the inside of a VTF3. http://www.hsuresearch.com/reviews/vtf3mk3rew.pdf

[JustPete]

This link shows the inside of a VTF3. http://www.hsuresearch.com/reviews/vtf3mk3rew.pdf

That's definitely not the tubes or amp of the VTF2m3. That amp is what I might have expected. The reality is something much different.

[Pete_Hsu]

Thank you for the feedback Pete. Go ahead and try these things in the enclosure to see if that minimizes the noise. I really appreciate your willingness to do all this.

FYI, the VTF-3 MK3 and VTF-3 HO are the models that have bent ports. The VTF-3 MK2 and VTF-2 MK3 have straight ports.

Sincerely,

[pontgranprix]

I recently bought 2 VTF3's and now you have me wondering.

[Pete_Hsu]

I recently bought 2 VTF3's and now you have me wondering.

The VTF-3 MK3 (in comparison to VTF-2 MK3) has larger and longer ports that bend internally in the cabinet.

[pontgranprix]

I was more concerned about the amp. I mean is it as tiny as he was saying or is it actually like the picture in that link?

[JustPete]

Thank you for the feedback Pete. Go ahead and try these things in the enclosure to see if that minimizes the noise. I really appreciate your willingness to do all this.

FYI, the VTF-3 MK3 and VTF-3 HO are the models that have bent ports. The VTF-3 MK2 and VTF-2 MK3 have straight ports.

Sincerely,

OK will do.

Like I said, and I hope I'm not giving off the wrong impression, the proof is in the pudding. And I like what I hear. The driver and cabinet overall looks solid and I am very happy with the sound.

I just happen to get one with a loose tube. I don't think fixing it will be a problem at all.

[Pete_Hsu]

I hear you Pete! We are very honored that you have such kind things to say about the sound quality of the unit.

Regarding the amp, I agree that it looks plain, but looks can be deceiving. These amps are very good. The continuous power is accurate as specified, and the peak power is somewhere around 2-4x higher too.

[JustPete]

I was more concerned about the amp. I mean is it as tiny as he was saying or is it actually like the picture in that link?

Looking at that picture, and my amp plate again, I'm probably over stating the amp size or lack there of. The one in the pic looks a little more substantial, but it should. It's a more powerful amp. I'm also comparing it to my memory of the Sunfire amp, which is admittedly a 2700w amp and way more expensive sub. Looking at this amp, it doesn't look bad, per se. Just different.

I'm also comparing it to a 220w stereo amp I had open to clean, and again, the comparison probably isn't fair because it's a totally different design.

Overall, it's really not bad at all.

[JustPete]

Mission accomplished.

I ended up removing the speaker as well to get better access to the tubes where they are set in the braces. The glue was only on 1/2 of one side and had actually broken loose. Tapping on the tubes produced the rattle I was hearing.

I took some packing foam sheeting and worked it in between the top of the tube and brace. This snugged the tube up nicely against the glued brace, Then I used high strength hot glue on both sides of the brace. Tapping on the tubes they are now completely rattle free.

I also wrapped the speaker cable with some micro fiber cloth and tied it at both ends.

Put everything back together and it is now very tight sounding and sounds fantastic!

No rattle at all now. :)

[Pete_Hsu]

Very well done Pete, I am thrilled to hear that! Thank you again for all the work that you put into this.

Sincerely,

[Lwang]

Modern amps could be highly efficient, converting almost all of the input power from the wall socket into output power via digital switching power supply, etc, thereby negating any need for heat sinks or such. Plus if they don't run any bias on it, there is no excess heat to dissipate. The sound quality of these amps over a full range might be questionable, but for low bass, then are perfectly acceptable.

They are also of bridged design, so they are 2 amps each a little more than 60 watts, hence, the amp size are even smaller.

[PolkSRS1.2]

Exactly. Remember the Carver Magnetic field power amps of the '80s (of which I run two) were revolutionary powerfull and light at just 23 lbs for 200-400 WPC and they run cool at full load without a finned sheat sink or fan.

Greg

[JustPete]

Very well done Pete, I am thrilled to hear that! Thank you again for all the work that you put into this.

Sincerely,

Glad to do it.

Just as a friendly suggestion, as I said when I discovered the problem, you really should consider putting some foam or other type cushion material on the surface of the braces where they meet the tubes. That little bit at a cost of pennies during manufacture, would prevent this from ever happening.

Last night I pushed it harder than ever before and it stayed solid and tight on the contrabass tones that would have had it buzzing before.

[JustPete]

Modern amps could be highly efficient, converting almost all of the input power from the wall socket into output power via digital switching power supply, etc, thereby negating any need for heat sinks or such. Plus if they don't run any bias on it, there is no excess heat to dissipate. The sound quality of these amps over a full range might be questionable, but for low bass, then are perfectly acceptable.

They are also of bridged design, so they are 2 amps each a little more than 60 watts, hence, the amp size are even smaller.

Exactly. Remember the Carver Magnetic field power amps of the '80s (of which I run two) were revolutionary powerfull and light at just 23 lbs for 200-400 WPC and they run cool at full load without a finned sheat sink or fan.

Greg

Yes I do realize amp technology isn't the same as it once was, ever since the introduction of Bob Carver's down tracking technologies. I also use a Sunfire Theater Grand in my home theater which seems to have limitless power and yet is a light weight compared to my old amps at around 35lbs.

It was just the surprise of pulling that plate and my expectation was to pull something that weighed maybe 5-10lbs and it probably weighs a pound at best. :D

At any rate ... it sounds great and works perfectly for it's intended purpose. Now that the rattle is gone, I'm very happy.

[WhskyTangoFxtrt]

Looking at that picture, and my amp plate again, I'm probably over stating the amp size or lack there of. The one in the pic looks a little more substantial, but it should. It's a more powerful amp. I'm also comparing it to my memory of the Sunfire amp, which is admittedly a 2700w amp and way more expensive sub. Looking at this amp, it doesn't look bad, per se. Just different.

It's probably trivial to compare the two plate amps. The VTF-2 MK 3 is a substantially more capable sub than the 10+ year old Sunfire Signature in regards to SPL and THD.

Congratulations on your troubleshooting and hope you can now enjoy your new sub.

[JustPete]

It's probably trivial to compare the two plate amps. The VTF-2 MK 3 is a substantially more capable sub than the 10+ year old Sunfire Signature in regards to SPL and THD.

Congratulations on your troubleshooting and hope you can now enjoy your new sub.

I'm enjoying it immensely, along with my other subs.

But, if you think the VTF2Mk3 is outperforming my Sunfire Sig Sub EQ ... well, you'd be in for a big surprise. Something tells me, that was a silly, ill informed dig.

The VTF3 begins to approach it's specs and output (according to claims). Calling either substantially more capable is ridiculous.

Further ... HSU's top of the line UL-15 subs use the same basic design Sunfire pioneered. Only real difference is the size of the driver being a 15" where as the Sunfire uses a 12" driver and 12" radiator thus actually providing much more driver surface area. Oh, and a much more powerful amp.

That aside, for 1/3 the price, I'm very happy with the VTF2.

[Lwang]

I'm enjoying it immensely, along with my other subs.

But, if you think the VTF2Mk3 is outperforming my Sunfire Sig Sub EQ ... well, you'd be in for a big surprise. Something tells me, that was a silly, ill informed dig.

The VTF3 begins to approach it's specs and output (according to claims). Calling either substantially more capable is ridiculous.
According to Secret's test, the Sunfire Sig EQ reaches 110dB with a combination of 20 Hz, 31.5 Hz, and 50 Hz, while the VTF3.3 reaches 116dB. Plus the Sunfire drops off below 20hz, while the VTF3.3 goes flat to 12hz. So the sunfire is still way behind, even if it has 2700 watts of amplifier (even though a 15amp line could only supply 1800 watts through the wall plug).

Further ... HSU's top of the line UL-15 subs use the same basic design Sunfire pioneered. Only real difference is the size of the driver being a 15" where as the Sunfire uses a 12" driver and 12" radiator thus actually providing much more driver surface area. Oh, and a much more powerful amp.Just because the two subs are cube shaped, doesn't mean they are similar. Much of the capability of the ULS-15 is in the driver, which gets lost by the spec readers.

[shadyJ]

I have a hard time believing that the VTF3 is flat to 12 hertz. It's a great sub, don't misunderstand me, I have two of 'em, but very very few subwoofers are flat to 12.

[Lwang]

I am only using reviews of the 2 mentioned sub from the same website/reviewer so that I could compare apples to apples. If it doesn't reach 12hz in your room, then the Sunfire would also not reach what the reviewer saw in his room.


http://www.hometheaterhifi.com/volume_13_1/hsu-vtf-3-ho-subwoofer-3-2006-part-4.html

http://www.hometheaterhifi.com/volume_12_3/sunfire-eq-signature-subwoofer-8-2005.html

[WhskyTangoFxtrt]

I'm enjoying it immensely, along with my other subs.

But, if you think the VTF2Mk3 is outperforming my Sunfire Sig Sub EQ ... well, you'd be in for a big surprise. Something tells me, that was a silly, ill informed dig.

The VTF3 begins to approach it's specs and output (according to claims). Calling either substantially more capable is ridiculous.

Further ... HSU's top of the line UL-15 subs use the same basic design Sunfire pioneered. Only real difference is the size of the driver being a 15" where as the Sunfire uses a 12" driver and 12" radiator thus actually providing much more driver surface area. Oh, and a much more powerful amp.

That aside, for 1/3 the price, I'm very happy with the VTF2.

Not intended to be dig at all -- just a friendly discussion. Just pointing out that a reasonable comparison would include the sub and its actual performance, as opposed to the perceived expectation based upon visual inspection of a plate amp. My point is that the Sunfire Signature was great for its size, but can now be bested after 10+ years of development and I believe that includes the larger, ported, HSU sub.

If you have the time, means or inclination; feel free to do a comparison with measurements and post your results. I think it would be interesting. My opinion as it stands now is based on the many threads, graphs and reviews I've come across.

Thanks for the feedback.

[JustPete]

According to Secret's test, the Sunfire Sig EQ reaches 110dB with a combination of 20 Hz, 31.5 Hz, and 50 Hz, while the VTF3.3 reaches 116dB. Plus the Sunfire drops off below 20hz, while the VTF3.3 goes flat to 12hz. So the sunfire is still way behind, even if it has 2700 watts of amplifier (even though a 15amp line could only supply 1800 watts through the wall plug).

Just because the two subs are cube shaped, doesn't mean they are similar. Much of the capability of the ULS-15 is in the driver, which gets lost by the spec readers.

You convieniently left off the part where the reviewer stated he had no doubt the Sunfire would hit its 116db output when corner loaded as the manufacturer claims.

And your suggestion about the ULS driver somehow seems to suggest the Sunfire driver is inferior where in actually, the driver is nothing short of amazing.

At any rate ... we're talking two completely different animals here and I didn't come here to get into a debate about Sunfire vs HSU.

I can tell you this much for a fact ... the Sunfire plays with power down to the first test tone on the HSU CD with absolutely no port chuffing. (for obvious reasons)

I have a hard time believing that the VTF3 is flat to 12 hertz. It's a great sub, don't misunderstand me, I have two of 'em, but very very few subwoofers are flat to 12.
That's a pretty silly claim. But I've found that a lot, when people like their gear it suddenly becomes the best stuff ever imagined. He neglects to mention this is with a tube extension box added that most would never want to run.

Personally, I think the VTF3HO specs are fantastic. If it sounds like the VTF2, and I have no doubt it does, at it's affordable price, it's a bargain.

There's no doubt, if you want to get really low, the longer the tube the lower she goes. But along with that also comes all sorts of noises some don't want, unless those tubes are rock solid. And so does a lot of port chuffing at moderate volumes and up.

I am only using reviews of the 2 mentioned sub from the same website/reviewer so that I could compare apples to apples. If it doesn't reach 12hz in your room, then the Sunfire would also not reach what the reviewer saw in his room.


http://www.hometheaterhifi.com/volume_13_1/hsu-vtf-3-ho-subwoofer-3-2006-part-4.html

http://www.hometheaterhifi.com/volume_12_3/sunfire-eq-signature-subwoofer-8-2005.html

Yes ... where in stating it's capabilities you conveniently left out this of the Sunfire ...

Although you can get a lot more bass out of a subwoofer if you place it in a corner, I tested it several feet out from the side and front walls.

Putting the subwoofer in a corner would add a few more dB, bringing it in right about at the manufacturer specification of 116 dB.

Now ... keep in mind, a 13" cube is doing that vs a sub the size of an apartment fridge. 2 different animals. Trying to put one down in favor of the other is silly.

[JustPete]

Not intended to be dig at all -- just a friendly discussion. Just pointing out that a reasonable comparison would include the sub and its actual performance, as opposed to the perceived expectation based upon visual inspection of a plate amp. My point is that the Sunfire Signature was great for its size, but can now be bested after 10+ years of development and I believe that includes the larger, ported, HSU sub.

If you have the time, means or inclination; feel free to do a comparison with measurements and post your results. I think it would be interesting. My opinion as it stands now is based on the many threads, graphs and reviews I've come across.

Thanks for the feedback.

I can already tell you for a fact, even though they're completely different animals, that VTF2 is not going to best the Sunfire.

I've already run the HSU test tones through the Sunfire , which is place at 45 degrees in a corner load set up, in a larger room no less. And it was unbearable. I was sure stuff was going to start breaking in the room. The sub did this without ever chuffing (of course) or creating any other anomalous noises. The beauty of a sealed design but obviously it requires lots of fast reliable power.

Having said that, there's no secret you can get much deeper bass or higher volumes. Build a refrigerator sized enclosure, add some 18" subs and 4ft long tubes and you'll do the trick with little power.

The Sunfire is a 13"cube that sits tucked invisible behind a plant in the corner.

Different animal. No less amazing. Superior driver and amp to either I've seen of the VTF's without question. I think even Dr. HSU wouldn't deny that. The ULS Driver looks to be of about the same level and design quality and even then the measured xmax on the 12" Sunfire driver is about 1.5" compared to 33mm (< 1.3") for the HSU.

Last ... just for the sake of discussion ... As some might notice, I don't mind digging in and finding solutions, which has saved me returning the VTF2 and noticeably improved the sound quality as delivered.

Something I never found a reviewer try with The Sunfire (And I would expect them not to do anything but test as delivered) ... it doesn't come with any feet to speak of.

I found the thing walking the floor. At high volume the distortion was audible and I thought that the culprit might be excess movement of the entire cabinet. So I placed a 50lb plate on it. The difference was night and day. The audible distortion peak at high volumes was coming from cabinet movement. All the sudden the sub became incredibly tight and musical. (And it sounded great before adding weight to the cabinet)

Since then I made a nice heavy plate dedicated to sitting on it. Makes the little cube weigh about 110lbs but was completely worth it.

So ... Let me say it again, rather then get into another debate about what's better as I don't think this is the place ... I am VERY happy with the HSU VTF2MK3 ... for it's intended purpose ... IMO it's a bargain and sounds fantastic.

[cacihome]

Hi,JustPete...

I have an Elemental Designs 18"driver (24" cubed box) in my setup paired with an ULS...
The elemental has a REAL Class AB 1300wrms amp with a huge toroidal transformer that weighs about 10lbs itself. Probably the most powerful amp in the market right now.(on the commercial sub world of ID companies), if I play the 16hz tone on it, sure it will "make a lot of sound", but those are the harmonics, and not the fundamental tone itself...Don't get confused here...What I mean is its easy to get confused with midbass performance that overpowers the low bass due to the human hearing limitations,etc...
While I dont doubt the Sunfire is a good sub until it gets to 25hz... below that it has to be weaker than the HSU. Make outside ground plane measurements and you will notice what I am talking about.

[Lwang]

You convieniently left off the part where the reviewer stated he had no doubt the Sunfire would hit its 116db output when corner loaded as the manufacturer claims.That is just the reviewer trying nicely to say the product met the advertising claim. But the apples to apples comparision is still that one hits 110dB and the other hits 116dB, both measured fro the same position.


That's a pretty silly claim. But I've found that a lot, when people like their gear it suddenly becomes the best stuff ever imagined. He neglects to mention this is with a tube extension box added that most would never want to run.

This is not some consumer making these claims of the Hsu sub going down to 12hz, or that somebody saying that they could faintly feel the 12hz note. It is what the reviewer indicated in his measurements.

[JustPete]

Hi,JustPete...

I have an Elemental Designs 18"driver (24" cubed box) in my setup paired with an ULS...
The elemental has a REAL Class AB 1300wrms amp with a huge toroidal transformer that weighs about 10lbs itself. Probably the most powerful amp in the market right now.(on the commercial sub world of ID companies), if I play the 16hz tone on it, sure it will "make a lot of sound", but those are the harmonics, and not the fundamental tone itself...Don't get confused here...What I mean is its easy to get confused with midbass performance that overpowers the low bass due to the human hearing limitations,etc...
While I dont doubt the Sunfire is a good sub until it gets to 25hz... below that it has to be weaker than the HSU. Make outside ground plane measurements and you will notice what I am talking about.

You might enjoy reading the White Papers published on the Sunfires. Interesting reading.

http://www.sunfire.com/whitepapers/Sunfire_Amplifier_Whitepaper.pdf

http://www.sunfire.com/whitepapers/Sunfire_Subwoofer_Whitepaper.pdf

Cheers ...

[JustPete]

Thanks again Pete / HSU. You make a fine product that I'll be recommending to anyone in search of a great, affordable sub.

With people I know, I'll definitely send business your way ... :)

[Lwang]

You might enjoy reading the White Papers published on the Sunfires. Interesting reading.

http://www.sunfire.com/whitepapers/Sunfire_Amplifier_Whitepaper.pdf

http://www.sunfire.com/whitepapers/Sunfire_Subwoofer_Whitepaper.pdf

Cheers ...
They forgot a 5th option, big box with big force, the Hsu way.

Sunfire's magnet: 225 oz.
ULS-15's magnet: 35 lb (560 oz).

Hsu had high bl woofers very very early on, hence its overdamped design.

Plus, the doc says Sunfire's p-p is 2.5", not 3".

[Pete_Hsu]

Thanks again Pete / HSU. You make a fine product that I'll be recommending to anyone in search of a great, affordable sub.

With people I know, I'll definitely send business your way ... :)

Thanks Pete, I really can't thank you enough :)

Regarding the Sunfire Sig model, Dr. Hsu has always been seriously impressed with what Bob Carver was able to do with that incredibly small enclosure. He has much respect and admiration for Bob Carver.

Guys, seriously, comparing the Sunfire Sig to a Hsu 12" sub is as apples to oranges as can be! There are positives and negatives to each respective design. That's just life, one can't have it all :D

[WhskyTangoFxtrt]

I can already tell you for a fact, even though they're completely different animals, that VTF2 is not going to best the Sunfire.

JustPete, I'm a little confused by your posts. You're all over the road here and I'm having trouble following you. It may just be me -- in which case, I apologize. Please tell me what fact you are referring too. What are the criteria you consider when forming an opinion on a subwoofer? Size, form, innovation, performance, measurements, cost, and value are all perfectly valid in my opinion and not necessarily arranged in that order.

You stated in your first post, "...of all my subs it's (VTF) equal to or surpasses their tone with a couple exceptions and for a lot less money..."

"It's very musical, tight bass on par with my others in that department."

"(The VTF is) dedicated to playing stereo music at moderate volume only and has never been pushed to see what it can do."

I've already run the HSU test tones through the Sunfire , which is place at 45 degrees in a corner load set up, in a larger room no less. And it was unbearable.

I think you would need to compare them in the same room and objectively take measurements to determine SPL, which I think you are trying to do here.

I was sure stuff was going to start breaking in the room. The sub did this without ever chuffing (of course)...

Isn't the Sunfire Signature a sealed sub? Do they produce chuffing?

...and would it produce chuffing? or creating any other anomalous noises. The beauty of a sealed design but obviously it requires lots of fast reliable power.

Having said that, there's no secret you can get much deeper bass or higher volumes. Build a refrigerator sized enclosure, add some 18" subs and 4ft long tubes and you'll do the trick with little power.

Ok, so we agree then? Although, I think there might be a little exaggeration as to the dimensions used here.

The Sunfire is a 13"cube that sits tucked invisible behind a plant in the corner.

Different animal. No less amazing. Superior driver and amp to either I've seen of the VTF's without question. I think even Dr. HSU wouldn't deny that.

Please explain your reasoning.

The ULS Driver looks to be of about the same level and design quality and even then the measured xmax on the 12" Sunfire driver is about 1.5" compared to 33mm (< 1.3") for the HSU.

Note that the ULS-15 is so named, because it utilizes a 15" driver as opposed to the 12" which has a bore of 10".

Last ... just for the sake of discussion ... As some might notice, I don't mind digging in and finding solutions, which has saved me returning the VTF2 and noticeably improved the sound quality as delivered.

Something I never found a reviewer try with The Sunfire (And I would expect them not to do anything but test as delivered) ... it doesn't come with any feet to speak of.

I found the thing walking the floor. At high volume the distortion was audible...

Distortion is usually not a desirable quality in a speaker. I've come across this Sunfire "walking" scenario before -- you are not alone.

...and I thought that the culprit might be excess movement of the entire cabinet. So I placed a 50lb plate on it. The difference was night and day. The audible distortion peak at high volumes was coming from cabinet movement. All the sudden the sub became incredibly tight and musical. (And it sounded great before adding weight to the cabinet)

My opinion is that an inert cabinet is part of the challenge and a design goal.

Since then I made a nice heavy plate dedicated to sitting on it. Makes the little cube weigh about 110lbs but was completely worth it.

So ... Let me say it again, rather then get into another debate about what's better as I don't think this is the place ... I am VERY happy with the HSU VTF2MK3 ... for it's intended purpose ... IMO it's a bargain and sounds fantastic.

Great! Well said. :)


Guys, seriously, comparing the Sunfire Sig to a Hsu 12" sub is as apples to oranges as can be! There are positives and negatives to each respective design. That's just life, one can't have it all

Also well said. Classy too.

[JustPete]

They forgot a 5th option, big box with big force, the Hsu way.

Sunfire's magnet: 225 oz.
ULS-15's magnet: 35 lb (560 oz).

Hsu had high bl woofers very very early on, hence its overdamped design.

Plus, the doc says Sunfire's p-p is 2.5", not 3".

That's a white paper on the middle sized sub with 10" driver and pre EQ. Not the Sig Sub with EQ and 12" driver. And the white paper descibes how commonly accepted problems are solved using ... ah never mind.

I'm not going to bother wasting my time.

[JustPete]

Thanks Pete, I really can't thank you enough :)

Regarding the Sunfire Sig model, Dr. Hsu has always been seriously impressed with what Bob Carver was able to do with that incredibly small enclosure. He has much respect and admiration for Bob Carver.

Guys, seriously, comparing the Sunfire Sig to a Hsu 12" sub is as apples to oranges as can be! There are positives and negatives to each respective design. That's just life, one can't have it all :D

I agree. And I NEVER meant for this to turn into some kind of bickerfest.

I'm very happy with your product and I hope for future iterations you take my small bit of friendly advice and cushion the end of that tube. I may be a more critical than usual customer, but I can't be the only one these tubes were loose on. And it was only a TINY bit loose. We're talking a millimeter of movement. Just enough to rattle badly.

I've already given my recommendation of your product to a group of fellow musicians/audio enthusiasts I know, and I will continue to do so.

[JustPete]

Great! Well said. :)

Also well said. Classy too.

I appreciate the response WTF ... But I really was here for one reason only. To solve a problem with an otherwise fantastic product. And I've done that.

I didn't come here to get into disagreements or have any of my other gear insulted. (not saying you did)

Everything I buy, I try to buy what's best for the intended purpose.

The HSU sits in a 14x20x9-11 room (vaulted ceiling) It's a room for relaxing in and playing music only, by the fire. I'm happy to say, the VTF2 is tight and fast sounding in its bass reproduction and the walnut cabinet was very nicely done fitting in beautifully with all the other woodwork in the room.

I'm very confident now it will serve well for many years and the rumors of the value HSU produces are not an exaggeration.

I have different gear all over my home. Sunfire in LR theatre set up with 60" screen (wanted power I could hide). SVS with Home Theatre 120" screen. Velodyne in BR with 50" screen. Theil C6's in a dedicated stereo listening room. Each serves their intended purpose to my utter satisfaction.

Now I've added HSU to the list.

[WhskyTangoFxtrt]

I appreciate the response WTF ... But I really was here for one reason only. To solve a problem with an otherwise fantastic product. And I've done that.

I didn't come here to get into disagreements or have any of my other gear insulted. (not saying you did)

Everything I buy, I try to buy what's best for the intended purpose.

The HSU sits in a 14x20x9-11 room (vaulted ceiling) It's a room for relaxing in and playing music only, by the fire. I'm happy to say, the VTF2 is tight and fast sounding in its bass reproduction and the walnut cabinet was very nicely done fitting in beautifully with all the other woodwork in the room.

I'm very confident now it will serve well for many years and the rumors of the value HSU produces are not an exaggeration.

I have different gear all over my home. Sunfire in LR theatre set up with 60" screen (wanted power I could hide). SVS with Home Theatre 120" screen. Velodyne in BR with 50" screen. Theil C6's in a dedicated stereo listening room. Each serves their intended purpose to my utter satisfaction.

Now I've added HSU to the list.

Thanks for sharing your experience. Enjoy.