I’ve never owned a subwoofer, but recently have been researching the possibility of getting one. I’ve read that one isn’t usually the best set up, since two subs help smooth out room nodes. I’m not eager to allocate money or floor space to two subs, but I can understand the reasoning. (And please explain if I haven’t understood correctly.) Just now, I saw a picture of a system on this forum with six subs (two stacks of three); I have also seen a couple of such arrangements on manufacturers’ websites.
Can someone please explain what is the deal here? I hope there is a good reason for using so many, but I really would like to know what it is. The cynical side of me thinks that manufacturers just want us to buy more units. I will also confess that I don’t find stacks of big black boxes attractive. My interest is two channel audio, not home theater; I don’t care about stomping dinosaurs or exploding buildings.
A left and right subwoofer makes acoustic music sound more real. Two subs also widens the soundfield. A pair of REL T/9 subs are small and won’t break anyones bank. They are easy to connect and tune. No special cables required.
Thanks. Your comment about acoustic music sounding more real is very interesting, and I can believe the effect on the sound stage of using two. I could (reluctantly) add two smaller ones to my system.
What really gets me are those pictures of systems with six. What the heck is going on there??
I have two small RELs and the best way I can describe the difference I hear with them on vs without is that they add a sense of air to the sound - which might be exactly the same thing Al is talking about with acoustic music. I can’t think of a better way to describe it - but I also know that I love what they did to my system.
IME, the room and main speaker placement are major factors in determining how many subwoofers one might need to reach a level of performance one desires. Depending on whether and where bass is emphasized and “sucked out” in your room with your current speakers, one subwoofer might go a very long way in smoothing things out in your system.
If I were you I would buy “Get Better Sound” by Jim Smith (it is inexpensive, but invaluable) and do everything you can to optimize the performance of your current equipment in your current room with its current furnishings, etc.
Once you are comfortable you have done as much as you can to eke out the best sound you can, spend a little money or exercise some creativity to properly deal with the first (and preferably second) higher frequency reflections from the side walls in your listening room.
Then, if you want to take the next step, add a single subwoofer and spend some time dialing in your system again. Get Better Sound can help you with this as well.
If you want to jump to a potential starting point with a single subwoofer, I recommend you start with it on the right side of your right speaker and about 1/3 into your room (measuring from the front wall). I would also place it a few feet away from the right wall to begin with. This just happens to be the general placement where I have gotten the best response with one subwoofer in my system. [And I read somewhere once that most of the LF-producing instruments in an orchestra are typically on the right side of the stage/pit from an audience’s perspective and you should provide that extra bass capability with one subwoofer by emulating the LF energy likely recorded in the right channel in stereo recordings .] YMMV depending on the LF acoustic characteristics of your room.
Once you have dialed in one subwoofer, you can explore the potential benefits of adding others. But at that point (if not sooner), I recommend you measure the frequency response you are getting with your system to determine what is happening with the LF wavelengths in your room.
Thanks for the extensive reply. I do have Jim Smith’s book already. (For those who haven’t heard of it, I agree with you that it’s very useful.) Based partly on his comments about using an RTA, I have recently tried to measure my room; see this post. As I said in the other topic, my room is such that I don’t have much leeway with speaker positioning (although of course even small adjustments can make an audible difference). I recently acquired a pair of Magnapan LRS+ speakers, their bass performance has exceeded my expectations, but it’s still nothing like what I got with the speakers I’ve been using for a very long time; hence my interest in subwoofers.
This is not 100% accurate. The Rel uses the hi level cable to help create its magic so the special cable is required good news it’s supplied with the subs!
I own a REL six pack. Once you hear a stack you realize it’s no hype, and no going back to just one or two. The height of the bass makes a difference in realism amongst other things. Trust the six pack reviews you read, they are true. I won’t expend the energy to elaborate further since it sounds your space is limited and you are not in the market.
Great speakers and a bargain that can’t be beat. I agree with Al the T9X would work great as would a S510 (recently discontinued). Rel has a warehouse sale now if you are working with on a budget.
I had Maggie 20.7s and 2 Rel Carbon Ltd subs complimented them greatly. I have MBL 101s and two Rel N31’s compliment them greatly. I would recommend long term to budget for two subs that might be smaller than one big sub. You will not regret having two. A six pack of subs makes a big difference but you need a very understanding spouse/significant other in the household or plan on being single
I had Two Rythmik G25HP which are dual 15" 1800 watt subs shared for HT and 2 ch. use via a JL CR-1. upon advise from right here on this forum I ended up with 2 more 12" subs using high level and took the big boys off for HT use only. I am not unhappy. The two 12’s running speaker level with my Sopra 2’s run very well together. it makes for a crowded room, but doing the subwoofer crawl for best placement worked and they landed where they did and its a dedicated room where wife has no say.
The biggest challenge of small room acoustics is bass, specifically the spatial variation caused by room modes - some spots have no bass at certain frequencies and huge bass at others and variation can easily be 20+ dB from position to position.
Harman did an interesting study on using the constructive/descriptive interference from multiple subs to largely solve this.
The REL stack doesn’t solve this but it does give you more output and dynamic headroom. When you space four subs through a room, they have smoother spatial response but the output is no more than that of a single unit.,
An even better solution to the Harman or REL approach (when you’re considering more than one listening position) is called Double Bass Array.
This cancels all the bass modes in a rectangular room and so you have essentially the same bass response in all locations. However, this requires 4-8 subwoofers.
Trinnov has an approach based around this they call waveforming.
In short, yes, multi subs can be incredibly useful.
As a side note, our new sub is going to have options for stacking as well as a wireless receiver built-in that has low latency 24 bit / 96 khz lossless signal and you can pair as main subwoofers together as you want to wirelessly. So, as long as you can get power somewhere, you can put a subwoofer there easily.
I got a personal demo of waveforming at the headquarters. It’s quite amazing. They played a 40hz or 60hz with standard room correction and the. With waveform. Standard it was good at seats terrible elsewhere. And not all seats great. Good but not great. Like a normal AVR. But when they turned on waveform woah every spot backwards forwards up down was spot on. No variation. Crazy.
Again 8 subs 2 top 2 bottom front and back. They had a 32” infrasonic sub too. We listened to music and it was good. The room was set up for movies. But I could imagine if set up for music. Movies amazing in that theater.
Reading that DBA article yeah they are using that method. @Chris_Brunhaver thanks cool article
My pleasure. This is a great topic. I was thinking about doing some youtube videos about advanced subwoofer setup. It would be timely with us launching a sub around the end of the year.
I might also do a white paper or some guides on advanced setup stuff like using the REW for room simulation and measurement or a tool like the multisub optimizer with the app controlled DSP functionality in the sub.
Even though some of our customer base could afford 8 subwoofers (when you consider that many subs are a small fraction of their total system cost), I think this would be a tough sell.
If you do the four sub version of Double Bass Array, it can still be effective (though not 100% mode cancellation like what you you heard). Maybe that’s something audiophiles would be interested in learning more about?
.] YMMV depending on the LF acoustic characteristics of your room.
