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electone
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Using a subwoofer for stereo music

Hi everyone. I have recently purchased the JVX EX-A10 micro system (http://www.hometheatermag.com/hometheaterinabox/906jvc/) which has an amazingly natural and breathy sound for the price. Since I'm only going to use it for stereo music playback, I was wondering whether the use of a small sub (JVC provides a sub output) unit (e.g. Velodyne CHT-8R or some of the small Yamaha YSTs) could improve the bass and the overall music quality or rather blur it (especially at this price level). Thus, I would appreciate any experience in using subs for micro stereo systems, or in particular for the afore-mentioned units. Thx in advance.

V. Delis
Patras, GREECE

jackfish
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Re: Using a subwoofer for stereo music

Yes. It looks like the low frequency extension of those speakers is 59Hz -3dB. I'd look at the low end SVS or Hsu subs. The REL T-1 is a little expensive but a good one.
http://www.svsound.com/products-sub-box-10nsd.cfm
http://www.hsuresearch.com/products/stf-2.html
http://www.sumikoaudio.net/rel/prod_t1.htm

Demondog
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Re: Using a subwoofer for stereo music

I think you'd want to use a modest subwoofer to match up better with the speakers you have. An 8" driver, or even a 10" will be sufficient. You also need a continuously adjustable low pass filter, and volume control on the sub amp. I wouldn't worry too much about power with a smaller driver. 125 watts RMS should be plenty

The Velodyne CHT-8R looks like it would do nicely.

The key to blending a sub to your speaker is to be subtile with it. Set the filter so there is not much frequency overlap between the sub and speakers. There isn't a lot of music below 60 Hz, depending on what you listen too, so the sub may not be making much of a contribution much of the time. Unlike home theater setups, it should not call attention to itself in normal listening. It should act as just a natural sounding extension of your speakers as they roll off.

What you want to avoid, is a situation I have experienced, where as the notes get lower they get louder, changing volume as they cross back and forth across the sub's filter set point, because I had the sub volume set too high.

On other occasions, I've had a sub level set way to high, and found the sub producing substantial output of frequencies that have leaked past the adjustable 18 dB/octave and fixed 36 dB/octave fixed filters

Add to this, the fact that the sub's bass level changes with changes in listening position. I guess what I'm trying to say is that it takes a bit of technique to get a basic sub set up to give you a natural sound to the music.

I use an SPL meter and a test disc with 1/3 octave tones to help balance the bass and speaker levels, but you can just do it by ear

commsysman
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Re: Using a subwoofer for stereo music

"There isn't a lot of music below 60 hz"????

Well, that's one opinion....

Personally, I would really miss the kettledrums and bass drums and electric bass guitar etc. if they weren't there. My Vandersteen 3A speakers are rated to go down to 30 HZ, and by themselves still do not reproduce that kind of bass well at all. I mean, you can tell that the stuff is there without the subwoofers, but it is very much muted...way in the background compared to how it should be. One thing that people forget is that high frequency information travels directly from the speaker to your ear, for the most part, but bass has long waves that permeate the ROOM, and tend to be attenuated by the room. A speaker may MEASURE a certain bass output (normally measured 1 meter from the speaker), but for bass to be heard, it has to set up a sound wave throughout the room, especially at the lowest frequencies! Therefore, in almost any room, the actual frequency response of your speaker below 70 HZ is probably MUCH worse than what is stated on the spec sheet!!

I can't imagine running smaller speakers without at least one subwoofer!

WITH the subwoofers...aahhhh...nice!

I love my subwoofers, lol!!!

Demondog
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Re: Using a subwoofer for stereo music


Quote:
"There isn't a lot of music below 60 hz"????

Well, that's one opinion....


If you noticed, I wasn't speaking against the OP getting a subwoofer.

As to the comment you isolated out of my post, I was trying to speak in a relative sense. A four string electric bass guitar has a frequency of 40 Hz and 55 Hz on the open E and A strings. So in my experience the majority of bass guitar is played above these frequencies. I turn my main speakers off quite often to hear what the subwoofer is contributing, and on a surprising amount of the songs I play (blues, rock, vocalists etc...) there's barely a muted bit of rumble out of the sub with the crossover set at 60 Hz, because notes lower than this are just not being played.

I made a point to say it depended on what you listen to, and kettle drums are one of the many instruments/types of music that do contain significant frequencies below 60 Hz. A couple others I listen to are Reggae, and synth bass. But I think most decent speakers will get down to 50 Hz and do an acceptable job of letting a person hear the vast majority of the music spectrum.

Of course if you want to get the truest reproduction, and the ability to feel your music as well as hear it, then true full range speakers, or subwoofers are absolutely necessary.

I use a subwoofer myself.

BTW- I use a CM-140 SPL meter and 1/3 octave test tones to set the crossover, and balance the sub level with the main speakers.

judicata
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Re: Using a subwoofer for stereo music


Quote:

I can't imagine running smaller speakers without at least one subwoofer!

If you have one subwoofer, why isn't it necessary to place it between the speakers for balance? In any event, it always seemed to me the best setup would have a subwoofer under/next to each speaker. I'm speaking with no scientific basis, but just what makes sense to me logically. I don't even have a sub, but it's always in the back of my mind.

Demondog
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Re: Using a subwoofer for stereo music


Quote:

If you have one subwoofer, why isn't it necessary to place it between the speakers for balance?


According to common thought, the nature of truly low subwoofer frequencies makes the source's location undetectable to human hearing. There are certainly people that will disagree with this.

It is recommended by some, to have two subwoofers, but not so much because of masking the sound's location, but to distribute the sub bass more evenly throughout the room.

judicata
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Re: Using a subwoofer for stereo music


Quote:

Quote:

If you have one subwoofer, why isn't it necessary to place it between the speakers for balance?


According to common thought, the nature of truly low subwoofer frequencies makes the source's location undetectable to human hearing. There are certainly people that will disagree with this.

It is recommended by some, to have two subwoofers, but not so much because of masking the sound's location, but to distribute the sub bass more evenly throughout the room.

Hmm. That makes sense to me - at least sort of.

JoeE SP9
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Re: Using a subwoofer for stereo music

In my experience using one sub with very small speakers requires a crossover point high enough that the position of a single sub can be quite noticeable. It's easiest to hear with a good minimally miked recording. The soundstage will shift to whichever side the sub is on. Using 2 solves this problem especially if the satellites are on top of the subs. If not using 2 then center placement is almost mandatory if you wish to preserve the soundstage. I realize this may not be the best for full low end extension. So a compromise is sometimes in order. Bass extension versus sounstaging, the listener has to make a choice.
Me, I use 2 subs crossed over at 75Hz. I would like to go lower but I can't fit larger ESL's in my room.

mrlowry
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Re: Using a subwoofer for stereo music

Using two (and a lower volume level to compensate) also has the advantage of pressurizing the air in the room more evenly, thus smoothing out response anomalies. Even if they are used at a crossover level that wouldn't make the SOUND directional they still should be used in the front of the room to reduce phase issues.

JoeE SP9
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Re: Using a subwoofer for stereo music

The phasing issue was important to me. I've got each sub quite close to its corresponding panel. Lucky for me I have a dedicated room.

commsysman
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Re: Using a subwoofer for stereo music

It sounds like we are substantial agreement there, lol.

On another subject that seems to be in the mix here; placement of a subwoofer in the room needs to be where it is effective in producing the bass waves throughout the room. With higher frequencies, the primary sound wave goes from the speaker in a line to your ear, and is directional in nature; not so with a subwoofer. When a subwoofer is working properly, it should be impossible to "hear" where it is located in the room; the bass is just present throughout the room, and it can be placed anywhere in the room that is practical and functional.

Jan Vigne
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Re: Using a subwoofer for stereo music

I haven't read this, but you can stick "subwoofer placement" or "subwoofer set up" in a search engine for more links.

http://www.audioholics.com/tweaks/speaker-setup-guidelines/crawling-for-bass-subwoofer-placement

A key piece of subwoofer performance is a function of where you sit more so than where the subwoofer sits. The sub can be perfectly postioned and, if you sit in the wrong location, you still won't hear a note it reproduces.

Kal Rubinson
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Re: Using a subwoofer for stereo music


Quote:
A key piece of subwoofer performance is a function of where you sit more so than where the subwoofer sits. The sub can be perfectly postioned and, if you sit in the wrong location, you still won't hear a note it reproduces.

I would not say "more so" but "as much as."

Kal

commsysman
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Re: Using a subwoofer for stereo music

I would be surprised if you "wouldn't hear a note" at some point in the room, but there are certainly peaks and nodes of bass waves in the room, depending on the specific frequency.

The thing to remember is that each frequency has a different wavelength, so the peaks and nodes in the room (for a given subwoofer position) are significantly different at say, 26 HZ and 36 HZ; not the same.

My main room is 15 feet by about 35 feet, except that at the end opposite the speakers there is a concrete block wall four feet high that goes about 2/3 of the way across, not a full wall, and then the dining room is behind that; kind of complicated to analyze; is the room really 35 feet long or do you have to add another 12 feet for that dining room back there?.

But one thing is for sure; when the bass from the subwoofers seems right at my listening chair, most low bass frequencies are even louder in the dining room and kitchen, which drives my wife up the wall on occasion...lol.

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