Two subs vs one (1 Viewer)

gadgtfreek

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I currently have a 12" Klispch sub-12, but was considering a good deal on two energy esw-8's.

The Sub-12 is rated to 24hz and the 8's to 36, but I wonder if having two spread out will sound better?
 

raoul5788

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You generally don't "hear" subs -- you feel them.

Conventional subwoofer wisdom holds that more drivers only makes the sound louder, not better.

If you aren't hearing the sub, you have SUBSTANTIAL hearing loss, your quotation notwithstanding. No pun intended, BTW.
 

gadgtfreek

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I did some more reading and you have to look at decibels. The two 8s are only 100 decibels, while the 12 is 117. Simple decision.
 

jayn_j

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If you aren't hearing the sub, you have SUBSTANTIAL hearing loss, your quotation notwithstanding. No pun intended, BTW.

I'd say it was the other way around. If you are HEARING the sub, it is running at too high a cutoff frequency, or you are using the sub to extend some wussy little satellite speakers that don't have bass. There is a place for satellite/sub systems, but I don't consider that a true subwoofer. It is a woofer, and usually I can tell exactly where the sound is coming from.

A good sub is meant to work below 60 Hz and is meant to be felt, not heard.
 

primetimeguy

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elwaylite said:
I currently have a 12" Klispch sub-12, but was considering a good deal on two energy esw-8's.

The Sub-12 is rated to 24hz and the 8's to 36, but I wonder if having two spread out will sound better?

Multiple subs are used to flatten the frequency response over a larger area. If that is your goal get another sub identical to your existing one. If you go with two of those 8 inch subs you will lose the output you currently have in the 24hz to 36hz range. So to me you are taking a step backwards.
 

primetimeguy

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jayn_j said:
I'd say it was the other way around. If you are HEARING the sub, it is running at too high a cutoff frequency, or you are using the sub to extend some wussy little satellite speakers that don't have bass. There is a place for satellite/sub systems, but I don't consider that a true subwoofer. It is a woofer, and usually I can tell exactly where the sound is coming from.

A good sub is meant to work below 60 Hz and is meant to be felt, not heard.

I'd say you should hear the frequencies the sub is producing, but not be able to localize them or know they are coming from the sub. Subs should blend with the other speakers such that you don't even know you have subs, it sounds as though bass is coming from your other speakers.
 

jayn_j

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I'd say you should hear the frequencies the sub is producing, but not be able to localize them or know they are coming from the sub. Subs should blend with the other speakers such that you don't even know you have subs, it sounds as though bass is coming from your other speakers.

We can probably get into audio geek territory pretty quickly. I guess it depends on the system you have put together. My opinion is that the system you describe is one where the sub is used to extend the bass of small bookshelf speakers. The main speakers are designed to drop off around 100 Hz or so, and the sub is used to fill in the bass below that. The thoery is that bass is non-directional to the human ear and you can't locate the source. Unfortunately for me, I am able to localize bass down to 60-80Hz, so I hear this sort of sub kick in and immediately notice where it is coming from. It is annoying to me to hear a motor start up on the left speaker and hear the lower frequency component comin right of center.

I'm not trying to knock satellite/sub systems in particular. They work in a lot of situations. I have one myself in my family room. We don't do critical viewing or listening up there, and keeping the speakers small was a consideration. However, down in the theater, I find I much prefer full range main speakers. I run Klipsch KG-4s down there with a 10" woofer and clean bass down to about 50 Hz. ON that system, I fill in the sub duties with a Velodyne RF-12a, which has its own 1200 W amp. I set the cutoff at the receiver and sub lower, to mostly give a boost below 50 Hz. The effect on my system is smooth bass at frequencies you generally hear coming from the main speakers, and sounds you feel coming from the sub. When the sub kicks in, it mostly shows up as a pressure in your chest.

I was trying to differentiate between the two types of system philosophy in my earlier post, but didn't do a very good job. My understanding is that Jason/Elway has a system closer to mine, as he upgraded main speakers a few months ago, so my comments were directed that way. Jason, I am not a big fan of dual subs, unless you are very careful on placement and matching. It doesn't seem to make much difference in smaller rooms. In larger rooms, it can improve sound by lowering the reflection time from the far wall. Most people who do it recommend placing the subs in the middle of the front and back walls, and place them some distance from the wall. If you look at this picture of my HT setup, you can see that my sub is about 18" off the screen wall. The room is only 13x20' and I don't feel it will help much to add the second sub though.
 

jayn_j

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Oh, let me add, I agree with Don about adding shakers. They provide the same sort of sensory bass. I don't have them in my current system, but I am starting to think about retrofitting the Berklines.
 

primetimeguy

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We can probably get into audio geek territory pretty quickly. I guess it depends on the system you have put together. My opinion is that the system you describe is one where the sub is used to extend the bass of small bookshelf speakers. The main speakers are designed to drop off around 100 Hz or so, and the sub is used to fill in the bass below that. The thoery is that bass is non-directional to the human ear and you can't locate the source. Unfortunately for me, I am able to localize bass down to 60-80Hz, so I hear this sort of sub kick in and immediately notice where it is coming from. It is annoying to me to hear a motor start up on the left speaker and hear the lower frequency component comin right of center.

I'm not trying to knock satellite/sub systems in particular. They work in a lot of situations. I have one myself in my family room. We don't do critical viewing or listening up there, and keeping the speakers small was a consideration. However, down in the theater, I find I much prefer full range main speakers. I run Klipsch KG-4s down there with a 10" woofer and clean bass down to about 50 Hz. ON that system, I fill in the sub duties with a Velodyne RF-12a, which has its own 1200 W amp. I set the cutoff at the receiver and sub lower, to mostly give a boost below 50 Hz. The effect on my system is smooth bass at frequencies you generally hear coming from the main speakers, and sounds you feel coming from the sub. When the sub kicks in, it mostly shows up as a pressure in your chest.

I was trying to differentiate between the two types of system philosophy in my earlier post, but didn't do a very good job. My understanding is that Jason/Elway has a system closer to mine, as he upgraded main speakers a few months ago, so my comments were directed that way. Jason, I am not a big fan of dual subs, unless you are very careful on placement and matching. It doesn't seem to make much difference in smaller rooms. In larger rooms, it can improve sound by lowering the reflection time from the far wall. Most people who do it recommend placing the subs in the middle of the front and back walls, and place them some distance from the wall. If you look at this picture of my HT setup, you can see that my sub is about 18" off the screen wall. The room is only 13x20' and I don't feel it will help much to add the second sub though.

Yes I agree. But when you have full range speakers with output to 50hz that is contradicting itself. :) Full range would be down to 20hz. That being said, I have system similar to yours with mains then have quality output into the low 40hz range. I still cross them over at 80hz and run two 12" subwoofers. There are pros to this approach such as less stress on the receiver amps, more headroom and can locate the subs where the bass is best (where as the fronts you want to image the best).

I felt I could always locate the sub when I only had one (at least the harmonics made it seem that way). Now it is impossible with two. When I went from one sub to two it was probably the biggest change I had made to my room/system up to that point (but now that goes to using Audyssey and Dynamic EQ). Have you measured the response of your room? Maybe you have a peak in the 60-80hz region and that is why you can locate it.

So for the OP I'd say two subs are good, but don't go backwards and get two 8" subs.
 

raoul5788

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I'd say it was the other way around. If you are HEARING the sub, it is running at too high a cutoff frequency, or you are using the sub to extend some wussy little satellite speakers that don't have bass. There is a place for satellite/sub systems, but I don't consider that a true subwoofer. It is a woofer, and usually I can tell exactly where the sound is coming from.

A good sub is meant to work below 60 Hz and is meant to be felt, not heard.

Are you saying you can't hear below 60 Hz?
 

jayn_j

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Are you saying you can't hear below 60 Hz?

Maybe. It is known that frequency response of the human ear drops off with age, and I am now in my '60s.

It is generally accepted that the absolute lower limit of human hearing is 20 Hz, but there is a BIG but here. The sensitivity of the ear starts dropping off rather dramatically below 200 Hz. You can look at the Robeson-Dadson curves or the more recent ISO 226:2003 curves and see that hearing response is dropping off 40 dB at 60 Hz and 50 dB at 40 Hz. And this is for someone in their late teens.

Wikipedia article: Robinson
Audiohaulics article: Human Hearing: Amplitude Sensitivity Part 1 — Reviews and News from Audioholics

So, you can hear it, but down at these lower frequencies with a big sub, you are going to start feeling it stronger than hearing it.

Note that it also means that speakers claiming this lower frequency response at a constant dB level, are misleading and assume the ear is linear.
 

mr_tv

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I put a second sub next to my seating area. It is in a bonus room over the garage and can really get the floor to moving under the seating. Shakers would do the same job as this so I like the effect. The second sub is along the left wall forward of the back left corner by about 5 feet. My first sub is built in wall just right of and below the screen painted on my front wall. The opening is about two feet from the front right corner of the room. It has worked out pretty well. While watching Master and Commander of the World for the first time I was wondering about the nails in the floor during the cannon scenes. My guests were pretty amazed at the feel, not sound, of the cannons going off.
 
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John Kotches

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Multiple subs are acoustically better than 1 subwoofer, assuming that the subs are identical and fed a mono signal.

Two at midpoints (either front/back or left/right) and four at midpoints, (front/back and left/right) give best results without going into crazy numbers of subwoofers. One of the acoustical engineers from HK (I forget his name) had an excellent study on this topic.

Cheers,

Sent from my Transformer Prime TF201 using Tapatalk
 

jayn_j

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I think I read that one, and I liked what I read.

The question I still have is: If you have x dollars to spend on subs, are you better off spending it on 2 mediocre subs or one good one? All too often this stuff is written without regard to price, assuming that the reader has an unlimited budget.

When I was faced with this question, I chose a nice 12" Velodyne over a pair of cheaper subs. I still think I made the correct choice, although if I were doing it today, I might choose a different high end sub, such as the Hsu.
 

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