mini/micro subwoofer thread

[carewser]

As for the thread topic, I would say those micro-subs are an engineering solution to a non-existing "yuppie" problem. If you are serious about audio but don't have the space or will to strategically place one or several normal sized subs (like a typical 12") then something is wrong anyway.

I don't know if it's a "yuppie problem" or not but i'm always baffled by people that claim they can't fit a full sized sub in their place as my place is 170sq/ft and I have 10 subwoofers in it, admittedly I live alone and most of my subs are small but still.....

 

[suttondesign]

For my linkwitz LXmini's in my living room, in front of bookcases, I needed to have small subs which are disguised as books. I used a .67 cu. ft. enclosure from parts express and then used the scanspeak revelator 9" alum. subwoofer driver and its companion (no longer produced) passive radiator, which I had to order from Australia. About $700 in parts for each sub. I then use individual MiniDSP plate amps mounted in a concealed area below my stairs and EQ the heck out of the subs to to get clean, usable response below 30hz. With the glued-on book spines, the subs are all but invisible and produce wonderful sound for a secondary system.

 

[617]

For my linkwitz LXmini's in my living room, in front of bookcases, I needed to have small subs which are disguised as books. I used a .67 cu. ft. enclosure from parts express and then used the scanspeak revelator 9" alum. subwoofer driver and its companion (no longer produced) passive radiator, which I had to order from Australia. About $700 in parts for each sub. I then use individual MiniDSP plate amps mounted in a concealed area below my stairs and EQ the heck out of the subs to to get clean, usable response below 30hz. With the glued-on book spines, the subs are all but invisible and produce wonderful sound for a secondary system.

Yeah if you get higher end drivers you can definitely get enough output for a smaller space. I have two Creative Sound Solutions sdx10 subs and frankly even one of them is more than enough in terms of output. Like, way more than I need, personally. This is a 10" driver in a sealed enclosure.

I think with the KEF unit it's probably not as good as they claim, but it's probably good enough to provide a lot of musical satisfaction for the typical LS50 owner. The problem then becomes how do you high pass the LS50s. It looks like this unit has RCA in and out so you can run your source into the sub and then back out to an amp after it removes the bass. Not a bad solution really.

I think KEF does themselves a disservice by saying it goes down to 11hz. You're not that guy, pal.

 

[raistlin65]

I don't know if it's a "yuppie problem" or not but i'm always baffled by people that claim they can't fit a full sized sub in their place as my place is 170sq/ft and I have 10 subwoofers in my place, admittedly I live alone and most of my subs are small but still.....

It's a WAF problem.

 

[YSC]

There's no replacement for displacement...

but there is also no replacement of not enough space to place a big sub~ you get absolutely nothing that way

 

[Adaboy4z]

I picked this little 6 inch sub up at local pawn shop, Episode Evo6-200. It didnt have a power cord or price on it. I borrowed a cord fron a stereo beside it. It powered on so I offered them $40 bucks and the manager said ok. I purchased a Kef Kube 12B a week before. The small sub sounds graet to my ears on music with Kef Q150s. it packs a thump on the lower end to my surprise. Oh and it has a mesh grill that snaps on and a nice black gloss finish.

 

[dlaloum]

I picked this little 6 inch sub up at local pawn shop, Episode Evo6-200. It didnt have a power cord or price on it. I borrowed a cord fron a stereo beside it. It powered on so I offered them $40 bucks and the manager said ok. I purchased a Kef Kube 12B a week before. The small sub sounds graet to my ears on music with Kef Q150s. it packs a thump on the lower end to my surprise. Oh and it has a mesh grill that snaps on and a nice black gloss finish.

Nice... often small driver subs actually sound better .... lower distortion?

 

[73hadd]

Yeah if you get higher end drivers you can definitely get enough output for a smaller space. I have two Creative Sound Solutions sdx10 subs and frankly even one of them is more than enough in terms of output. Like, way more than I need, personally. This is a 10" driver in a sealed enclosure.

I think with the KEF unit it's probably not as good as they claim, but it's probably good enough to provide a lot of musical satisfaction for the typical LS50 owner. The problem then becomes how do you high pass the LS50s. It looks like this unit has RCA in and out so you can run your source into the sub and then back out to an amp after it removes the bass. Not a bad solution really.

I think KEF does themselves a disservice by saying it goes down to 11hz. You're not that guy, pal.

If we can live with a 6db slope, isn't this just a 200mfd capacitor in front of the LS50 to start the roll off at 100hz, for example? I am not knowledgeable and haven't tested this so someone tell me I'm wrong. I want a passive high pass that doesn't mess with phase too much. I would prefer to split the output after the preamp instead of going thru a sub, as I am not confident about what is happening to the signal in/thru the sub.

 

[anotherhobby]

Small/mini subs definitely have a place. I've been incredibly happy with a pair of small 8" sealed subs that I built. The best part of working from home for me, without question, is being able to have my own private audiophile system to listen to music ALL DAY. However, my wife also works full time across the hall, so listening levels are pretty low most of the time. My office is only 115 sq/ft with a door, and with EQ these little subs sound fantastic! The face is just 9" square, and they are 14" deep, externally powered by a Crown XLS1500 (rated @ 525 watts per channel into 4 ohms). This is what tehy look like:

But it all depends on the specific setup and driver used. Something like an Dayton UM8 is practically unlimited in the low end because it has enough power handling.

The Dayton UM8-22 is the driver I chose for my subs, and they do indeed go surprisingly low in my small office, playing pretty flat to 12 Hz at my listening levels. No, they don't go loud and won't win any SPL wars, but they responded really well to EQ, and they rock for near field listening at my desk. Below is my room response with and without EQ (paired with Revel M105s). I should be able to tidy it up quite a bit more when my new miniDSP Flex arrives. Right now I'm just doing EQ from my Mac.

For my linkwitz LXmini's in my living room, in front of bookcases, I needed to have small subs which are disguised as books. I used a .67 cu. ft. enclosure from parts express and then used the scanspeak revelator 9" alum. subwoofer driver and its companion (no longer produced) passive radiator, which I had to order from Australia. About $700 in parts for each sub. I then use individual MiniDSP plate amps mounted in a concealed area below my stairs and EQ the heck out of the subs to to get clean, usable response below 30hz. With the glued-on book spines, the subs are all but invisible and produce wonderful sound for a secondary system.

This sounds awesome! Do you have any pictures? I'd love to see how they turned out!

I'm frequently surprised and impressed with how much these little subs add, how full they sound, and how low they go. In the Rhiannon Giddens song Julie from her Freedom Highway album, there is a constant very low very soft beat that's there throughout the entire song. I'm assuming it's from her or one of the other musicians bouncing a foot, or maybe the heel of their hand on an instrument. I can just barely hear it on my byerdynamic Amiron Home headphones, but it's completely inaudible on my Revel M105s. With these little 8" subs, it's clearly audible and I can feel that little beat pressurize my ears when the door is closed.

 

[Nevi]

I could imagine there are two camps. I belong in the one that favor small subs. Before I got the Kef KC 62, I had 2 Bowers and Wilkins ASW 608. One in my living room, and one in my bedroom. I use a Kef KC 62 now in my living room, together with a pair of Kef LS 50W II.
The other B&W sub, is in my bedroom, with my Denon surround, with B&W speakers front, and 4 Dali in back-sides. That ASW 608 is a 8 inch in a closed enclosure, and with their usual DSP, that make a gradual 6 DB slope downwards. First time I heard them, I was surpriced over the agile deep digging sound. To explosions and stuff in movies, bigger subs would probably be better, but to music I prefer small subs. But I know bigger subs absolutely can be awesome and agile. The surround in my bed room, have plenty explosions, and boom bam. I have the sub in a corner, and the coupling to the room is really good.
I do know it's possible to use big subwoofers, with fast agile sound though. The best I heard was a servo sub from Paradigm.

 

[dlaloum]

I have a strong feeling that the big subwoofer fraternity is heavily North American ...

Which may partially relate to the size of the rooms in which they are used, as well as the type of building contruction.

I think the NA vs many other areas/countries distinctions in terms of speaker preferences may have quite a bit to do with home sizes, listening room types, and construction methods.

Most substantial difference between many UK/Euro designs and NA ones is often in the Bass & speaker sizes.

A smallish listening room, with solid brick or concrete construction, is going to need a lot less oomph to energise the bass, than a large room with drywall/frame construction - and the speakers that sound great in the first, will sound puny and underpowered in the latter.

 

[RickSanchez]

New low-priced "desktop"(?) subwoofer entry from Audioengine, the S6. $299 USD list price.

• https://audioengineusa.com/shop/subwoofers/s6-compact-powered-subwoofer/

Specs (from Audioengine)

• Type: Powered Subwoofer, sealed enclosure
• Amplifier Type: Class D
• Power Output: 210 W peak power total (140 W RMS), AES
• Drivers: 6″ long throw front-firing woofer
• Inputs: 3.5 mm stereo mini-jack, RCA L/R
• Input Voltages: 100-240 V AC, 50/60 Hz auto-switching
• SNR: >100 dB (typical A-weighted)
• Frequency Response: 33Hz – 132Hz ±1.5dB
• Input Impedence: 10K ohms unbalanced
• Crossover Frequency: 40Hz – 130Hz
• Protection: Output current limiting, thermal over-temperature, power on/off transient protection
• Standby Consumption: <1W
• Phase: 0 / 180 degrees

Dimensions

• Dimensions (HWD): 10″ (25.2 cm) x 8.7″ (22.2 cm) x 10″ (25.3 cm)
• Weight: 15.4 lb (6.98 kg)

 

[BadAudioAdvice]

Note sure if these are exactly micro/mini, but Parts Express carries a Dayton Audio 10" subwoofer w. 100watt amp that is only 6" tall:

Shopping

I like that it in addition to line level inputs, it has speaker level inputs, so it can be run it in between speakers and older stereo amplifiers that don't have a subwoofer-out signal.

 

[carewser]

^That's another solution for an unhappy spouse since you can
hide it under furnitire. My 8" Paradigm sub can be placed vertically or horizontally so I should try it horizontally since in the upright position the bass is unimpressive

I got the email from Audioengine about their new 6" sub since i own a pair of their A5+ speakers and their bigger 8" sub (which produces fantastic bass) although I was surprised because Kanto pulled their 6" sub off the market

 

[Plan9]

Whoever the OP is, he's an idiot because he didn't specify what constitutes a microsub or a minisub because I suspect almost all my subs falls into these two categories

Sorry, calling someone you don't know an "idiot" regarding their subwoofer post borders on idiotic....we're just talking about subwoofers, small ones at that...oops I said small, not micro nor mini...yikes

 

[MarkS]

@Plan9, I think you missed the fact that @carewser is actually extremely well acquainted with the person he's criticizing ...

And that the comment is from a year and a half ago ...

 

[fineMen]

Many different forms of motional feedback do exist, either with an independent sensor or with using the voice coil itself as the sensor.
Even the driver proper is applying motional feedback to itself when voltage-driven, the lower its Qes the more so.
Would be a topic one could sure expand on in a different thread.

I think it was Purify who suggested to use a dome tweeter (!) as a sensor for the internal pressure of a speaker box. And they did it to some significant success. Pressure moves the dome, the voice coil of which generates a voltage which can be measured. Movement is small due to the high resonance frequency of the tweeter, hence linearity is maintained. Robustness should be warranted by the quite tiny air pocket behind the tweeter's dome. It won't compress by a large amount, preserving the dome's shape easily.

The internal pressure is at any time proportional to the outside sound pressure, even with ported speakers, if the enclosure is small compared to the wavelength. This could serve as a sensor for motional feedback--the most simple solution I ever heard of.

Should I do it? The needed electronics is a simple as it gets ...

 

[fineMen]

I think it was Purify who suggested to use a dome tweeter (!) as a sensor for the internal pressure of a speaker box. ...
Should I do it? The needed electronics is a simple as it gets ...

I started:

This is the not calibrated signal of a mini neodym powered tweeter mount inside a subwoofer. It shows that the woofers operate quite linearly with an outside level @1m of about 93dB. Hd2/3 contribute, to the total sound, about 1..2% (-40dB) in subbass, and less than 0,1% above 100Hz. This relates well to previous outside measurements using a microphone.

This is the raw drivers in-box w/o eqalization. The phase response worries me a bit in regard to a stable feedback. I've resonances presumably from the flexing support of the light tweeter inside the box.

 

[Ricardojoa]

New low-priced "desktop"(?) subwoofer entry from Audioengine, the S6. $299 USD list price.

• https://audioengineusa.com/shop/subwoofers/s6-compact-powered-subwoofer/

Specs (from Audioengine)

• Type: Powered Subwoofer, sealed enclosure
• Amplifier Type: Class D
• Power Output: 210 W peak power total (140 W RMS), AES
• Drivers: 6″ long throw front-firing woofer
• Inputs: 3.5 mm stereo mini-jack, RCA L/R
• Input Voltages: 100-240 V AC, 50/60 Hz auto-switching
• SNR: >100 dB (typical A-weighted)
• Frequency Response: 33Hz – 132Hz ±1.5dB
• Input Impedence: 10K ohms unbalanced
• Crossover Frequency: 40Hz – 130Hz
• Protection: Output current limiting, thermal over-temperature, power on/off transient protection
• Standby Consumption: <1W
• Phase: 0 / 180 degrees

Dimensions

• Dimensions (HWD): 10″ (25.2 cm) x 8.7″ (22.2 cm) x 10″ (25.3 cm)
• Weight: 15.4 lb (6.98 kg)

Hard to believe those specs are real.