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mini/micro subwoofer thread

carewser

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So many manufacturers are getting into this these days I thought it worthy of a thread, particularly since I own a number of small subwoofers. Kanto, REL, Velodyne, PSB, Sunfire, SVS and KEF have all come out with mini/micro subs and i'd like to see thoughts, specs, reviews and suggestions for them. While most of my subs are small they aren't particularly expensive either-usually just the sub that comes in a 2.1 multimedia/computer speaker system from the likes of Klipsch, M-Audio, Acoustic Authority, Logitech, Altec Lansing, Edifier and Corsair. The only standalone sub I own is the Audioengine S8 which I thought was pretty impressive until I saw the specs on the KEF K62. I can't even imagine how any 6 1/2" driver can even come close to doing what it does, it really defies physics and the mini subs from the other manufacturers I mentioned aren't exactly slouches either
 

KSTR

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Transducer design has improved so that now we have true long-stroke 6.5" drivers with low distortion and high output capacity. And with enough amp power you can make a closed cabined as small as you dare. Plus better electronics are available which improve on the distortion issues as well, with various forms of motional feedback, up to the point your're frying the voice coils :)
 

Victoria

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This is definitely an interesting topic and I’ll be following this thread closely! I haven’t used a subwoofer in a really long time but I’m slowly contemplating upgrading my main speakers so who knows maybe I’ll be swayed again!~

I’ve also noticed that subwoofers with dual opposing drivers have been becoming more popular again lately, so don’t forget that in the case of the KEF KC62 two 6.5” drivers would be somewhat equivalent to a single 9” driver in terms of the total surface area there is to push air around; and woofer diameter is ultimately what makes their respective cabinets big, bulky and unsightly; so I’m definitely happy to see them shrink.

Admittedly however I have no idea if you can really compare subwoofers like this, but if there’s anyone here who can comment on how comparable a single larger driver is versus two smaller ones I’d love to hear!
 

Jim Matthews

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Is not the essential ingredient for high SPL the volume of air moved?

I don't know precisely how to compute the "crossing point" but I suspect smaller diameter drivers must necessarily roll off at higher frequencies if they're to play loud.

Deeper
Louder
Smaller

Pick any two...
 

Victoria

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I think some manufacturers are compensating with so-called “long-stroke drivers” in order to compensate for lack of woofer surface area though I’m clueless as to how effective they are and where they stand in terms of long-term reliability.

Also don’t forget that many consumers very much confuse “deeper” with “louder” and think that a given subwoofer — or hell, even speaker — has “good bass performance” just because they were artificially boosted at the lower-mid frequencies (60-80Hz?) but are completely incapable of producing any sound what-so-ever at true low frequencies from 40Hz down to 30Hz and especially further down to 20Hz; and manufacturers know this.
 

sweetchaos

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Seeing how much interest there is for micro-subs, I’d love to see SVS 3000 Micro and Kef KC62 measured using CEA2010 protocol.
When someone (either Erin, Audioholics, or HomeTheaterReview) posts measurements (hopefully soon), I’ll update my ‘subwoofer comparison’ spreadsheet, so we can dive deeper into the numbers to see how well they stack against the competition.
 

dannut

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Micro subs are perfect for the helper sub role in multi-sub arrangements. Modal smoothing is required only in the 40-150Hz region, also they usually end up a good 6-10dB lower in level than the main sub. So if you can't hide them, make them small and pretty. 'Designer' subs like Cambridge Minx, MartinLogan etc. are good options. Now the KC62 and SVS3000 could be also used as a main sub, if you can't hide a larger one somewhere in your room.
 

Ron Texas

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There's no replacement for displacement...
 

digitalfrost

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For those considering DIY, I built very small subwoofers with http://www.tb-speaker.com/products/w5-1138smf. You need multiple chassis to get any meaningful output, but as the drivers are not expensive it's not really a problem. You can get away with 10 liter boxes.

w5sub.png
4540_4.jpg


As you could expect, distortion is quite high, but should still be OK.

SzRA7CM.png
 

richard12511

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Transducer design has improved so that now we have true long-stroke 6.5" drivers with low distortion and high output capacity. And with enough amp power you can make a closed cabined as small as you dare. Plus better electronics are available which improve on the distortion issues as well, with various forms of motional feedback, up to the point your're frying the voice coils :)

Motional feedback like what Grimm Audio uses in their subwoofer modules?
 

KSTR

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Motional feedback like what Grimm Audio uses in their subwoofer modules?
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.
 
OP
carewser

carewser

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There's no replacement for displacement...

I think the KEF KC62 basically blew that idea out of the water-KEF claims it goes down to 11hz which means it goes deeper than just about any subwoofer i've ever heard of and has a power rating of 1000 watts RMS. I can't remember which online reviewer tested it but they said it "only" goes down to 15hz (which is still crazy deep) considering the only sound that goes that low is a pipe organ which KEF's little sub can reproduce accurately. Let me try and put that kind of bass in perspective. The 7" subwoofer in my Logitech Z623 system puts out 130 watts RMS and goes down to 35hz. That little subwoofer has made two houses i've lived in, rattle, so just multiply the wattage by over 7X (and yes I know it's nowhere near 7X louder but still.....) and make the bass more than twice as deep and it becomes hard to imagine the bass that little box can generate. No wonder it's 2 grand here in Canada.
I’ve also noticed that subwoofers with dual opposing drivers have been becoming more popular again lately, so don’t forget that in the case of the KEF KC62 two 6.5” drivers would be somewhat equivalent to a single 9” driver......

But wouldn't two 6.5" drivers be the same as one 13" driver?

Motional feedback like what Grimm Audio uses in their subwoofer modules?
I just checked out their subs and they're the first upward-firing subs i've ever seen but I couldn't find a driver size anywhere on their site
 
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FrantzM

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I think the KEF KC62 basically blew that idea out of the water-KEF claims it goes down to 11hz which means it goes deeper than just about any subwoofer i've ever heard of and has a power rating of 1000 watts RMS. I can't remember which online reviewer tested it but they said it "only" goes down to 15hz (which is still crazy deep) considering the only sound that goes that low is a pipe organ which KEF's little sub can reproduce accurately. No wonder it's 2 grand here in Canada


But wouldn't two 6.5" drivers be the same as one 13" driver?

I am waiting for reviews to see at what SPL it goes to 15 Hz @ 2 meters ...
As for the 6.5 the cone area formula is (pi/4) x diameter ^ 2
So for one 13 inches diameter driver , surface is (3.14/4) x 13^2 = 133 Square inches
For one 6.5 it is 33 square inches; for 2 it would be "just" 66 square inches, about half the area of just one 13"diameter driver ....
Overly simplified to make a point.. the driver is not a flat circle but likely, a cone and you need to know the apex, etc ... Let's keep it simple OK? :D
 
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carewser

carewser

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^yeah thankfully it only requires advanced training in Newtonian physics to understand
 

More Dynamics Please

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^yeah thankfully it only requires advanced training in Newtonian physics to understand

Should be pretty obvious to anyone with average eyesight that two speakers of half the diameter of a larger speaker are not equivalent to the larger speaker, as when comparing two upper case O in 9 point type vs. one upper case O in 18 point:

OO O
 

Ron Texas

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I think the KEF KC62 basically blew that idea out of the water

But wouldn't two 6.5" drivers be the same as one 13" driver?

Your math isn't any good, nor is your physics, aside from being on the impolite side.
 
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carewser

carewser

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Your math isn't any good, nor is your physics, aside from being on the impolite side.

"Impolite"? Huh?

I didn't know I had to be good at math to be a member here, I thought I just had to be into audio equipment
 
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carewser

carewser

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^So the passive radiator is 5 1/4" I'm guessing by it's looks, the driver is also 5 1/4"
Micro subs are perfect for the helper sub role in multi-sub arrangements. Modal smoothing is required only in the 40-150Hz region, also they usually end up a good 6-10dB lower in level than the main sub. So if you can't hide them, make them small and pretty. 'Designer' subs like Cambridge Minx, MartinLogan etc. are good options. Now the KC62 and SVS3000 could be also used as a main sub, if you can't hide a larger one somewhere in your room.

Cambridge Audio is yet another company that makes a couple of mini subs although their 6 1/2" Minx sub doesn't go any deeper than any of my much cheaper 6 1/2"-8 "subs but it can play louder
 
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