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Old May 27th, 2015, 1:16 PM
acepaul acepaul is offline
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Arrow VTF-15H Mk2 Review - Part I & Part II

To start off, I just want to mention that for the last several years I have been corner loading a Velodyne CHT-12 and, while it does provide a bass boost, it failed miserably to keep up with the rest of my system. I planned to replace it with a single sub and picked the VTF-15H Mk2 for the job.

I forgot what ordering a big-ticket item online is like and felt like a kid again waiting for Christmas. Multiple shipping status checks and several visits to the Hsu forum kept me going. I arranged and rearranged furniture, tweaked the EQ on my Denon and many other useless things as I impatiently waited. The package arrived on time and I had the weekend to set it up.

I was concerned about the health of the unit as it is a very heavy item and shipping accidents can happen. As I unpacked the box, I was reassured by the quality packing job. Even though there were a few dents and dings on the box, everything was in perfect shape. The box is fairly impossible to carry around with just one person, but a single person can unpack it easily. The manual, test CD and cord were all neatly packed as well.

After removing the sub from the box, I needed to place it in my predetermined location. At first, I set it on a blanket and dragged it around but eventually found that tipping it up and walking it was the quickest way to move it. I did pick it up a couple times to put it on a higher surface for the sub crawl, but cant recommend this with just one person as you can easily damage your back. It is heavy!

The sub cabinet has a nice black matte finish and is very sturdy. Even with the amp and woofer removed, it is extremely heavy. The beefy rubber feet on the bottom seem practically indestructible and provide a good isolating support for the unit that will work equally well on carpet or hard floors. The front grill is sturdy and the mounting system is very solid. The woofer looks and feels well built and has quality spring-loaded connectors for the wires from the amp. The amp has a variety of controls that all have a quality feel. The switches are crisp and the dials have a smooth and weighty feel to them. The circuit boards look well laid out and all parts that might vibrate or move such as cable connections have been glued in place. Both woofer and amp are well secured and sealed to the cabinet, but can be quickly removed if needed.

I originally hooked theVTF-15H Mk2 to my Denon 3806 via RCA cable as there is no balanced output. With a shielded cable length of 50 feet, there is no detectable distortion. Per the instructions, I set the volume knob to about 9:00. I also set the Q control to .5 and the crossover switch to Out. My first impression was no less than outstanding. I could not believe the amount of quality and tight bass this unit put out! If my old Velodyne were a dog, it would have tucked its tail and slunk out the back door in shame.

I settled on one port plugged and the EQ 1 setting. For movies the Q at .7 is the most satisfying while I like the punchy .3 for music. During the opening scene of LOTR, the floor and couch pleasantly shook and vibrated at times. At first, I though that the vibration was transferring from the cabinet to the floor, but when I placed my hand on the unit, very little vibration was detectable. This baby moves some air! The organ piece that comes on the HSU demo cd was amazing. 16hz is more of a feeling than a sound.

As my ears were opened to what bass is really supposed to sound like, I started fine-tuning my system. My theater is located in a 21x16 loft that is open to a 21x20 two-story great room. Sound spills out into over 10,000 cubic feet of open space. Energy C-9s are the mains and C-3s are the surrounds. I have an Energy CC-1 and CC-3 that provide dual centers above and below my 120 screen. Two Energy CB-10s bring up the rear. Another pair of C-3s is an honorable mention down in the great room for music listening. All ceilings are beam and car decking and the walls are sheetrock and wood paneling. No acoustic treatments are installed nor are they likely to be (WAF).

After hours of tweaking and listening, I was getting frustrated with the limitations and obstacles presented by my room acoustics and placement options. I could not achieve a balanced sound that ranged across the entire listening area. After quite a bit more research, I came to the conclusion that I needed(wanted ) two things: a MiniDSP and one more VTF-15H Mk2!

In Part II I will go through receiving the second unit, a challenge, excellent customer service from HSU, and MiniDSP setup with dual subs. Coming soon...

Part II

Again I found myself anxiously waiting for the FedEx truck to arrive. I first ordered the MiniDSP and a UMIK-1 USB mic. I also purchased the 2way Advanced plugin for the DSP and downloaded REW. I then ordered the second MK2. There was no point in rearranging the furniture any more so I fiddled with the DSP plugin, which I found fairly simple and straightforward to use. As luck would have it, both items arrived right before a weekend so I had some time to get things set up.

I first decided that I would play around with the placement of both subs, though their final resting place at both front corners was inevitable. It was now time to throw the MiniDSP into the mix and start running some tests. I did not buy the unit with balanced connections as there really was no point considering the distances involved. After hooking up the UMIK-1 and firing up REW, everything was ready for final testing and adjustments. I did run the calibration on the Denon first just to get the distances tweaked. The 3806 has no sub EQ so there was no other real benefit.

After running a few test sweeps, I started to notice that there was a problem. Things just were not sounding right and the response graphs were not quite what I expected for dual subs. I decided to mute first one sub and then the other to see where the individual levels came in. This was when I made a horrifying discovery the newest sub was not working! Frantically, I checked and rechecked cable connections, MiniDSP settings and finally swapped cables between subs. It made no difference - the sub was dead.

According to the manual, if this should happen, the woofer would need to be removed and tested to see if it was working or if the amp was the culprit. I ended up swapping woofers between units (later I was kindly told that it is much easier just to switch the amps face palm) and determined that the amp was not working. I checked the boards and connecting plugs and could find no obvious problems. It was Sunday, so I shot off an email to HSU so they could get it first thing Monday morning. I was surprised and relieved to receive an email back a little later that day (on Sunday!) apologizing for the problem and reassuring me that a replacement amp would be sent out ASAP. I made a follow up call on Monday and had a tracking number that afternoon.

A few days later, the replacement amp arrived and it was a matter of minutes to have everything back together and ready to go. I have to reiterate that these subs are well built and will be very easy to service and maintain. After lugging the sub back to its home and double checking connections, I cleared the MiniDSP settings and ran the Denon calibration again. I was ready to get down to business.

The crossover on the Denon was set to 80Hz and that seemed to produce the best results. I unplugged the main speakers and ran sweeps on just the subs. The volume knob on both subs was set to a little past the 9:00 position and I used the MiniDSP to make fine adjustments for level matching. There is also an option to introduce individual delay for each sub. As the delay of one sub is adjusted, some low frequencies increase while others diminish. Depending on sub placement and room acoustics, this is a good tool to use before applying EQ. My subs are fairly equidistant from the MLP so no separate delay was necessary.

With the 2way Advanced plugin there are 6 master EQ bands and a master gain for each input and each input feeds into two outputs. There is a crossover, another 6 EQ bands, gain and delay for each output. A person could truly spend days tweaking and measuring with all the possible adjustments, though you can produce great results after just a couple hours. The available headroom and extension with dual MK2 subs allowed me to also apply a house curve that really showcases the ultra-low frequencies. Both subs were set in the EQ 1 position with one port open. I adjusted the Q to .7 since I mostly use the system for home theater. I ended up using all the bands of the input EQ, including the first band to apply the house curve. I used one band in each of the individual EQs to reduce a problem frequency. Without applying expensive acoustic treatments to the room, the response will never be perfect, but it is a vast improvement.

The overall difference in experience is stunning! It is the aural equivalent of going from old black and white to full HD color. There are so many movies to re-watch now. But even with all the sci-fi and fantasy options that have skillfully crafted bass, one of my favorite scenes remains Darla tapping on the fish tank in Finding Nemo. It will split your house in two! The organ piece on the first track of the HSU demo cd will rearrange your insides as you realize how thoroughly music can be felt.

A few final conclusions to wrap things up. You can certainly spend more on a subwoofer, but the law of diminishing return is in full force here. I realize that my space is larger to fill than average and most people would be blown away with just one of the MK2 units. With two, there are not many reasons to ever need more. Strong, loud, tight and precise bass is the end result of this setup. HSU has done an amazing job of delivering superb quality at this price point.

There are always going to be problems with any manufacturer. The occasional dead unit or damage from shipping are realities that we all deal with. HSUs excellent and prompt customer service took the risk out of buying from an ID company. I did purchase the 5-year warranty on the electronics for both subs and feel it was money well spent.

With the dual setup (and perhaps even one), the MiniDSP is an essential tool to balance the subs and reduce the inherent problems each listening room has. From what I have read, even the latest Audyssey systems perform poorly when it comes to making adjustments for lower frequencies. I hope this information is helpful to those who are setting up a sub or are considering the purchase of a VTF-15H Mk2.
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