“Let our rigorous testing and reviews be your guidelines to A/V equipment – not marketing slogans”
Facebook Youtube Twitter instagram pinterest

NHT Absolute Tower Set Up & Sound Quality Tests

By

NHT Absolute Tower BoxThe cardboard box surrounding the NHT Absolute Towers makes you think a much larger loudspeaker is coming out.  The speakers are very adequately protected with several thick foam ribs and a foam base and top.  The base of the loudspeaker comes in a separate box and is attached with four Phillips head screws.  The pair of Absolute Towers arrived in perfect condition.

In recent months, I have moved to a new home with a very different living room than what I’m used to.  Since my reference open-baffle loudspeakers take quite a bit of breathing room, they do not work in the new living space.  I’ve since designed a pair of large bookshelf speakers to overcome the placement issues.  There is a terrible null in this room at 80Hz, which I typically use RTA to analyze, and equalization to mask.  Given this, I only use this room for home theater testing.  The system in this room consists of an Oppo BDP-105 connected directly to an ATI 1505 amplifier.  The subwoofer out from the Oppo BDP-105 is connected to a miniDSP for bass management before routing to a HSU 12” subwoofer.The loudspeakers are approximately 8 feet forming an equilateral triangle with the listening position.

For two channel listening, I use a 12’x14’ office with a large area rug over hard floors.  In this configuration, I use Audirvana running on a MacBook connected to a high quality DIY Buffalo III SE digital to analog converter (DAC) via USB.  The DAC is based on the same converter chip used in the BDP-105 but has an excellent linear power supply and a different current-voltage stage yielding a slightly warmer bottom end.  The USB input interfaces with Audrivana and allows high resolution DSD playback.  I typically sit 6 feet from each speaker in an equilateral triangle.  

Sound Quality Tests

These listening tests were conducted in the mentioned listening environments without any form of room correction or high-pass filter for music. 

Café Cubana – SiboneyCafe Cubana CD

I had to go back to this recording because it is first recording I’d ever heard that made me realize the merits of audiophile systems compared to the unbalanced systems I had grown up with.  Instead of pumped highs and bloomy low frequencies, audiophile systems handled the midrange in a way that was simply more lifelike.  This combined with discovery of stereo imaging elicited a new passion that still burns strong.  While this recording is not the pinnacle of recording quality, it does present a very life like piano, bass and set of congas that just do not sound real without a good midrange presentation. 

After finagling with the Absolute Towers I found toeing them in slightly so I was sitting directly on-axis provided the best sound and imaging to my ears.  The speakers sound very good overall and have a great tonal balance leaning slightly toward the bright side.  In fairness, the Absolute Towers were designed for use with a subwoofer and I do not have one set up in the office.  This speaker sounded very fast and very clean at any volume I dare listen to it.  The stereo imaging was present but is not the speaker’s strongest suit.  What did strike me is the clarity in the upper bass.  The speaker is designed for a flat response summed with a subwoofer at 80Hz instead of trying to fake the bass response as many other small towers do.  Craving some integration with a subwoofer, I moved these to the living room setup. In the living room, the seamless integration with the subwoofer was easy.  I set the subwoofer to an 80Hz crossover point, level matched using a calibrated RTA and was on my way in just a few minutes.  The clean and fast bass response of these speakers was excellent.  I found that in this acoustic environment, the imaging was not as good but their excellent frequency response made for a very enjoyable listening experience.

Lindsey Stirling – Crystallize

I’m not a huge fan of electronic music but this track really has a good mix of low, middle and upper bass that isn’t found in many recordings.  Lindsey Stirling is an excellent American violinist that mixes her performances with electronica.  In the living room with the subwoofer in place, this recording comes alive with smooth bass transitioning perfectly from subwoofer to the Absolute Towers.  The stereo panning of the violin oscillates gently from the center creating an ethereal smearing of the violin that you chase around the acoustic scene as you listen.  Several synthesizer pads play in the background that have a sense of non-locality.  This song is fun to listen to on the Absolute Towers.

Lindsey Stirling

Lindsey Stirling - Lindsey Stirling

Tuck & Patti – Time After Time

This recording has that analog tube recording feeling:  It’s just a warm sounding recording with tons of dynamic range and imaging in spades.  The Absolute Towers did not disappoint on this song either.  Everything sounded lush and the Absolute Towers were able to handle the dynamics of this song at very loud volumes without any evidence of strain.  There was a slight sibilance in the treble region but this is likely due to room acoustics.

Tuck and Patti - Tears of Joy

Tuck and Patti - Tears of Joy

Hi-Res DSD: Keith Greeninger & Dayan Kai – Looking For A HomeBlue Coast Collection

The merits of high-resolution recordings have been questionable to my engineering brain.  In school, I was taught that there is a reason CD’s were cut at 16 bit and 44.1kHz and the reasoning is very convincing.  Audiophiles, prepare to scoff. I haven’t heard a discernable difference beyond my own doubt when downsampling high-resolution music so long as the sample rate was an integer multiple of the original (For Example 96kHz to 48kHz). However, this recording is way different.  There is just something about this recording that I haven’t heard in any other music.  I tried converting the DSD track to a lossless AAC track using Korg Audiogate but the sound quality was noticeably worse.  I do not know if the algorithm Korg uses causes aliasing issues, but I do know it was not the same.  I tried the same thing with 2L albums with similar results.  Is DSD that much better?  I’m not really sure but there is a level of realism to DSD that I cannot explain.

With that out of the way, this track with the Absolute Towers back in the office is out of this world.  The realism of the duet and guitars through the Absolute Towers and a high quality DSD capable DAC is an experience to say the least.  Imaging was good and it just feels live and intimate and evokes the feeling music should. 

 

Confused about what AV Gear to buy or how to set it up? Join our Exclusive Audioholics E-Book Membership Program!

Recent Forum Posts:

Steve81 posts on August 13, 2014 12:40
konajoe, post: 1045846
But, in this particular case, the author went out of his way to report that this speaker was different in this respect.

Hi Joe,

The issue in question isn't uncommon:
Between the crossover point of 2.2kHz and 5kHz, the tweeter is transitioning across the angled chamfer, increasing the output off-axis. This seems like a good thing because the response is close to linear when sitting up to 30 degrees off axis. However, this has consequences in rooms without acoustic treatments.

This is a simple matter of a directivity mismatch, which is to say a 1“ tweeter will have a very wide dispersion pattern at the bottom of its passband (i.e. where the wavelengths are large with respect to driver diameter), while a 5.25” midrange driver's dispersion will be narrowing at the top of its passband (i.e. where the wavelengths are getting smaller with respect to driver diameter).

There are a couple common ways around this:

1. As seen in NHT's Classic 4 tower and Classic 3 bookshelf, you can use a smaller midrange driver; in the case of the NHTs, they use a 2" dome midrange down to 800Hz, which ensures a wide dispersion pattern throughout the midrange.

2. Use a waveguide or horn to constrain the tweeter's dispersion, which you can see on a lot of Harman speakers (JBL, Infinity, Revel), KEF, etc.

XTZ also looks to have an interesting solution with their Cinema series, i.e. use an array of tightly spaced tweeters down to a lower XO point of 1.2kHz, with only one of them handling the band above 3kHz.
alphaiii posts on August 13, 2014 12:19
I think the reviewer is making the point that, because of the chamfered baffle, some excess off-axis energy in the 3-5kHz range is projected into the room… In a reflective room, this excess may be perceived as brightness, or unforgiving mid-treble. As the reviewer mentions, some placement adjustments can help counter that.

I found the Absolute Towers to sound bit forward in my room, and liked the Classic Three better (which did not sound forward in my room)… but I can't say it was because of that 3-5kHz region…
AcuDefTechGuy posts on August 13, 2014 12:07
konajoe, post: 1045846
But, in this particular case, the author went out of his way to report that this speaker was different in this respect. He doesn't say “unforgiving in reflective rooms” about all speakers. He goes out of his way to explain, in depth, why this would be so. I'm not sure he would go out of his way to note this as a ‘con’ if it were true for all speakers.

As a total newb, I hate to appear that I am disagreeing with knowledgeable folks who have been very helpful.

My younger brother still has the NHT SuperZero bookshelf speakers + SW2P sub I gave him. The NHT system now resides in his large family room. This room is reflective as hell - I mean you can hear the echo when you clap your hands.

Amazingly, the NHT still manages to sound good.

I think the take-home message here is that in general, great speakers tend to sound good in most rooms. They sound best in the better rooms, but they still sound pretty good in lesser rooms. These NHT speakers are just one such example.
zieglj01 posts on August 13, 2014 11:36
konajoe, post: 1045846
But, in this particular case, the author went out of his way to report that this speaker was different in this respect. He doesn't say “unforgiving in reflective rooms” about all speakers. He goes out of his way to explain, in depth, why this would be so. I'm not sure he would go out of his way to note this as a ‘con’ if it were true for all speakers.

As a total newb, I hate to appear that I am disagreeing with knowledgeable folks who have been very helpful.

NHT does not make sharp/edgy and aggressive speakers - their speakers do measure nice.

I have owned about 85 sets of speakers, including some NHT ones - and the room/rooms, are important.
None of these speakers would sound good with hard and reflective surfaces all around. Now it is really cool,
what reducing reflections can do - with something like carpet/rugs, curtains, some soft furniture - and with
some pictures and/or other type things on walls that do help. Do not need to get real fancy - however, it is
cool and nice, to even tame the first reflections.

Your option choice and call - do what you wish - may (hope) you enjoy the adventure.
konajoe posts on August 13, 2014 06:34
But, in this particular case, the author went out of his way to report that this speaker was different in this respect. He doesn't say “unforgiving in reflective rooms” about all speakers. He goes out of his way to explain, in depth, why this would be so. I'm not sure he would go out of his way to note this as a ‘con’ if it were true for all speakers.

As a total newb, I hate to appear that I am disagreeing with knowledgeable folks who have been very helpful.
Post Reply