Are big subwoofers viable for 2 channel music?

Hello John,

    
      I've always built my systems based on the assumption that bass content on virtually all music and HT source material (LPs, CDs, SACDs, DVD and Bluray, digital files, etc.)  only had bass extension down to 20 Hz since any recorded bass below 20 Hz was generally filtered out at the mixing stage.  
     I've been almost certain this assumption was correct and the complete story until you and phusis informed me that a group of AVS forum members had figured out a method, using a mini-DSP, that allows the retrieval of any bass content still existing on numerous specific Bluray and DVD discs that's below 20 Hz.
     This was the first I was aware this was even possible on certain discs, so I wanted to thank both of you for bringing this to my attention.  As I stated, I'm very satisfied with my current system's bass performance on both music and HT even though it's currently restricted to only 20 Hz in bass extension.  
    However, I am curious about experiencing how I would perceive even further bass extension in my room and system.  I understand I would need to upgrade my current Audio Kinesis Debra 4-sub distributed bass array system, or at least the existing four 4 ohm passive subs with 10" aluminum long-throw drivers it uses, along with adding a mini-DSP unit to realize high quality deep bass below 20 Hz.  Even then, I understand this deeper bass would only accessible on certain HT Bluray and DVDs.  I think whether I decide to proceed depends on your answer to the following question:

     Does the mini-DSP also allow retrieval of deeper bass content on audio only discs such as CDs and SACDs?


Thanks,
 
 
 
   

@noble100 --

I think our disagreements and differences expressed on this thread can be boiled down to a difference in preferences and priorities. I could go into detail but I believe it basically comes down to both of your top priorities seeming to be the optimum bass extension of your sub systems for HT Bluray 4K Ultra HD audio performance and my top priority being the optimum bass quality of my sub system for 2-ch stereo music hi-res digital music file audio performance. I think both are enjoyable and worthy goals. But why can’t we have both?

Even though I fully acknowledge the impact <20Hz reproduction can have and that there’s plenty of source material to support it, not least watching movies via Blu-ray’s and UHD’s, as I’ve stated earlier I’ve chosen to consciously forego infrasonics in my own set-up. This is due to the nature imposed by design limits mostly, in addition to practical considerations in regards to sheer size; tapped horns, my preferred bass principle, are bandwidth limited to covering about 2 to 2 1/2 octaves cleanly (some would say 1 1/2 to 2 octaves, but it depends on the specific TH design and its weighted parameters within the given fold/expansion/compression ratio), and therefore a lower tune will at the same time "eat away" of the upper range that can be achieved. For those not in the need of a cross-over frequency above 50-60Hz here, 15Hz honest extension (or even lower in-room) can be had from tapped horns the likes of which count Josh Ricci’s monstrous Gjallarhorn V2, the Danley DTS-10 or lilmike’s LilWrecker. Apart from upper range limitations naturally imposed on these designs there’s also size to consider as they climb upwards of 30 cubic feet in volume, not to mention the added weight that follows. Moreover, a lower tune with tapped comes at the cost of sensitivity, though relative to direct radiating designs they are typically still more efficient even when tuned rather low. My MicroWrecker’s have a ~23Hz tune @97dB sensitivity that gives clean extension upwards to about or just below 100Hz, and with a 78Hz lowpass in my system to the mains (36dB/octave Linkwitz-Riley) no irregularities from the upper band of the MW’s interfere in the presentation. Highpassing the mains above some 70Hz has advantages in relieving them more effectively, but the exact cross-over frequency is one to be found with careful listening. A highpass at 20Hz (4th order Butterworth) protects the bass drivers of the MW’s downwards as they unload below the tune (in domestic use mostly to reduce theoretical distortion rather than over-excursion), and so 20Hz is pretty much the "hard deck." With the pair of MW’s this translates to +125dB’s SPL envelope and honest 20-25Hz reproduction. Some may regard such SPL capabilities in domestic environments as insane, but when faced with the effortless reproduction they deliver at any SPL one would care for, even having impact down to 60-70dB’s, it makes perfect sense.

So, my preference and priorities revolve around attaining the bass that best integrates with my mains as well as acquiring prodigious amounts of headroom, and this requires going the (tapped) horn route with massive physical size to follow, as well as bandwidth limitations to consider. Infrasonics make a difference, for sure, but I’d rather attain optimum integration and overall bass presentation, to my liking, and sacrifice <20Hz with the given tapped horn design. Choices, and compromises.. (sorry for lengthy elaboration above).

Hello phusis,

     Thanks for your detailed response.  I now have a much better understanding of your system preferences, priorities and goals. I looked at your system pic and description on your profile page and admire the unique and independent path you decided to take on your personal audio journey.  
     Your system certainly looks unique, interesting, beautiful and impressive, I'd love to hear it, or a similar one, in action sometime.  You're obviously telling the truth about the size and weight of TH subs.  I like the looks of your subs and main speakers but, if I was to switch to THs in my system and living room, my wife would likely be chasing me around our house with a large frying pan targeted at my head.
      I have a limited understanding of the appeal of horn speakers, their efficiency, sound qualities, dynamics and ease even at very high SPLs.  The first pair of speakers I purchased as an adult in about 1979, was a brand new pair of the original Klipsch Heresy speakers, in unfinished birch wood to save some money, for exactly $300/pair.  
     I really enjoyed those speakers during college with a TT, 40 watt ss Yamaha CR640 receiver and no sub.  I still regret not knowing enough about audio at that time to at least try using a tube amp with them. Now I use 1,200 watt class D monoblock amps with a pair of inefficient planar-magnetic speakers and 4 subs.  Oh well.

Thanks,
  Tim

     @noble100, I apologize for the delay in replying to this thread. The Mini-Dsp helps optimize the information on ANY audio format. It can be used in a variety of ways, one of which is optimizing up to four sub-woofers. If using the Mini-Dsp for sub-woofers you can adjust the timing, volume, delay and more for each sub-woofer individually.  Separate adjustments for each sub-woofer would also require a separate amplifier channel for each sub.  

     If you want to further optimize your system, In My Humble Opinion, the first thing to do is measure your in room response, or after the health scare is over, have someone else measure it for you. During the measurement phase, use one speaker as a timing reference and correctly time all of your speakers to work together. In my room, correct timing made a big difference.

     After measurements and timing adjustments, if you still want to improve your system, I suggest doing some reading on the Mini-Dsp and consider using it to optimize what you already have. I believe most enthusiast change speakers without ever hearing them at their best. Once/If you reach the limit of what your speakers can do, then consider replacements.

     Another option available after the health scare is to find someone near you with different speakers, that will demo their system for you. Listening to someone else’s room and equipment is a great way to make new friends and hear something different. If you like what you hear then you can decide if and how to implement the changes in your room. 

Stay Safe!   

John

Hello John,

     No problem with the delay, I usually just check for new responses on threads once a day, no hurry.  I’ve heard about the mini-DSP previously but the benefit of retrieving more recorded bass information from recordings is new to me.       I’d be very interested in hearing a high quality system using multiple subsonic subs and a mini-DSP playing both music and HT source material.  I think I’d need to experience the increased bass extension in person to determine whether updating my bass system would be worth time, effort and expense involved, which would include 4 new subsonic subs, the mini-DSP and learning how to properly use it.  I’m currently torn because I’m fairly certain I would enjoy the added bass extension, likely perceiving it as being even more realistic and palpable than my current system which I perceive as having near sota bass response even though the bass extension is limited to 20 Hz. 
     There’s also the advantage of how convenient my current system is to operate and it’s overall simplicity.  I just use an Oppo 205 Blu-ray player as a 5.1 Audio surround processor, with surround output channels run direct to separate amps and speakers for HT. And a separate preamp with ht passthru for music. The 4-sub bass system, with a separate sub amp/control unit that has settings for xover frequency, volume and phase, switches automatically between the summed bass on music and the LFE bass on HT based on the preamp input I select.     This is very convenient because the settings on the sub amp/control unit don’t require changing for either music or HT, they remain constant with a xover of 40 Hz, volume at just under 50% and all subs in-phase.  It’s basically set and forget. I’m concerned this won’t be true with the addition of a mini-DSP.
     I completely agree with you about the benefits of getting my room measured.  However, I was considering buying a good mic, downloading REW to my laptop and doing the measurements myself.  I thought this would be a good method of learning the details of room measurements and gaining experience in understanding the relationship between objective measured room response and my subjective perceptions of the sound in my own room and system.
      Thanks for all the very useful info.

Tim