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How can I keep tight & fast with more extension at my budget

henry1234

Established Member
I have a M&K KX10

http://www.mksound.com/pdf/spec_sheets/spec_subs/MK_KX-10_sub_specsheet.pdf

As part of a necessary move over to compact home cinema last month it came as part of a package with my M&K K17 and K4's

After selling my enormous B&W ASW1000 this sub is a breath of fresh air. To me it is fast, tight, punchy and rhythmic and just enjoyable to listen to everyday. Despite the xover at 120hz there is no localization. My old sub was set at 80hz and gave it's position away and never kept up with the rest of the audio. It just rumbled whereas the M&K sings a tune.

The only thing is despite a nice smooth low end and no distortion the ultimate low end extension - slam or sofa shaking or that silent room loading in your ears is lacking. The sub is only 8inch and tiny so I suppose that makes sense.

There is no way I will go backwards with regards to speed and rhythm, what do I need to look at to get the big low end slam?

Also you may have suggestions for subs that are even faster and rythmic? Although I can't imagine the need for more.

My budget would probably be around £400-500 s/h and it must be as small as possible.
 

HiFiRuss71

Distinguished Member
A lot of what makes a sub sound slow IS deep bass. That and it's interaction with the room.

The interaction with the room is something smaller subs avoid by simply having less output at the frequencies affecting by the rooms longer dimensions. It's easy to see that they reach the 45-50Hz range effected by the floor to ceiling distance, but the time the room is say 16ft long, it's unlikely a small sub/driver will produce significant output to drive the 22-25Hz room modes. Biguns will manage this no problem.

So it's a bit of a double edge sword. Deeper bass sounds slower and causes the resonances that add to the effect.

The best bet is to invest in an EQ device, whatever sub you buy. Suppressing all of the problem peaks in the frequncy response will tighten the sound dramatically and allow you to hear through to the, previously masked, lower frequencies without the sub sounding overbearing and thick.

Due to your size constraints and the fact that you're working with high crossover frequencies (and at the risk of upsetting certain factions :rolleyes: ), I'd have a look at the SVS SB-12/plus. Have a look here. And here for the forum powerbuy.

It's compact, not too far over budget, sports room size compensation and single band parametric EQ functions and is about 14" cubed and has a 45day money back guarantee. I've met it a couple of times and it's very, very good. The EQ functions will help suppress too much room gain and the PEQ will let you target the worst peak - there's nearly always a worst peak. Throw in one of the best sub specific drivers in the business with 425w up it's chuff and I really can't think of anything from the mainstream brands, that I've heard, that even come close for the money.

You may not even miss the B&W.;)

Russell
 

Helicon

Banned
Not being funny, but i think you'll find most modern subs will sound faster and tighter than an ASW1000.....it was never the most agile sub at the best of times.

The KX10 is a great little sub for the money, and if you're pleased with the overall sound of the KX10, why not try it's bigger brothers? Either a KX12, or even better, a VX-850, which keeps the tight, tuneful bass you're used to, then kicks serious ass when needed. Those subs that try and produce as much sub bass as possible usually lose out in the speed and agility department, and affecting their rythmic abilities as you found out with the B&W. Stands to reason really.

I changed from a 10, to a 12, then to the 850. Huge difference each time. You wouldn't be dissapointed.
 

HiFiRuss71

Distinguished Member
Those subs that try and produce as much sub bass as possible usually lose out in the speed and agility department, and affecting their rythmic abilities as you found out with the B&W. Stands to reason really.

I changed from a 10, to a 12, then to the 850. Huge difference each time. You wouldn't be dissapointed.
Is that the subs that loose out, or the effect of actually having deep bass present? I honestly feel both can co-exist, with some effort.

Either way, there's a s/h VX-850 going on a well known auction site at the moment.;)

Russell
 

Helicon

Banned
Is that the subs that loose out, or the effect of actually having deep bass present? I honestly feel both can co-exist, with some effort.
I agree, but it comes at a price. Budget subs can produce low bass, but their cheaper drivers and lack of cabinet build quality and bracing usually means the low bass lacks control and sounds too boomy. This is when localisation at sub frequencies comes into play.

Damn! If that 850 was in black i'd have gone for a second one :(
 
K

kramskoi

Guest
I have a M&K KX10

http://www.mksound.com/pdf/spec_sheets/spec_subs/MK_KX-10_sub_specsheet.pdf

As part of a necessary move over to compact home cinema last month it came as part of a package with my M&K K17 and K4's

After selling my enormous B&W ASW1000 this sub is a breath of fresh air. To me it is fast, tight, punchy and rhythmic and just enjoyable to listen to everyday. Despite the xover at 120hz there is no localization. My old sub was set at 80hz and gave it's position away and never kept up with the rest of the audio. It just rumbled whereas the M&K sings a tune.

The only thing is despite a nice smooth low end and no distortion the ultimate low end extension - slam or sofa shaking or that silent room loading in your ears is lacking. The sub is only 8inch and tiny so I suppose that makes sense.

There is no way I will go backwards with regards to speed and rhythm, what do I need to look at to get the big low end slam?

Also you may have suggestions for subs that are even faster and rythmic? Although I can't imagine the need for more.

My budget would probably be around £400-500 s/h and it must be as small as possible.
the answer is probably sealed 15" and 18" drivers with a Qtc. of .5 or (preferably) less...you maintain control over the room modes but the sub comes alive only when it really needs to...you'd never know that i run a 3x15" until i put on "Pomps and Pipes"...the pressurization of the room is tremendous when the source calls for it...at Qtc's of .42 and .45, the system strips away all the bloat and delineates bass in ways few subs can match...definitely squash the 8 inch driver...15 and 18" multiple sealed is the way to go for tight, visceral bass...:smashin:
 
K

kramskoi

Guest
And would completely ignore the OPs last eight words.:rolleyes:

Russell
oh heck...maybe i'm the one that needs some help...:rolleyes: :oops: i'm stuck on the DIY track these days:boring: , which usually falls far and away from commercial offerings...so point taken...m
 

Nimby

Distinguished Member
It is said that deep bass takes time to build from the leading edge transient to maximum SPL and then decay to nothing.

I think it depends entirely on the sub-bass transducer.

Given enough cone area and the power to accelerate and stop it rapidly enough there is no slowness to bass as low as you can still hear.

Giant boulders crashing together and explosions have plenty of low frequency content. Do they sound slow? Nope.

Small cone excursions and large cone area reproduce very low bass which starts and stops instantly. (Whatever the frequency or level)

Does the bass sound slow at a concert where there are great banks of large drivers and kilowatts of power? Well the semi-domesticated version is the true IB subwoofer. Though the concept still has few admirers despite the staggering SPLs and LF extension on offer.

As Russell has observed: Emasculated subwoofers have no low bass to slow things down. The more distortion they produce the quicker poor subwoofers may sound. Since the easily-produced, but false, higher harmonics easily mask the usually weak fundamentals.

The easiest way to "quick" bass IMO is careful positioning of what you have already (between the main speakers and well away from corners) and/or electronic (parametric) equalisation to kill room modes. (which hang about long after the host has lost patience)
 

HiFiRuss71

Distinguished Member
I was thinking along the lines of a 20Hz signal takes four times longer to build to full SPL than, for instance, an 80Hz signal.

The leading edge of any musical note, is a complex structure of many sounds, of many frequencies. Even a deep double bass note will have harmonics in the 1000s of Hz. These I feel will sound as if they 'arrive' quicker with the fundamental building behind albeit milliseconds later. If the 80Hz tone takes 4 milliseconds to hit peak SPL, then 20Hz will take 12. Not alot, but 5ms delay on the lipsync on my projector drives me nuts, so I believe it's a perceivable difference, however subjective and increases with the depth on offer.

That good old stick/slapped bass favoured by Tony Levin is a good example. The initial strike that gives this style such impact, has little to do with the depth of the note that follows. I also consider that a deep bass instrument/note will consider ringing for longer. The reproduction of these deeper notes will give rise to a certain 'perceived' slowness. The lack of weight to the note following, by a small sub, could easily be misconstrued as fast bass, missing as it does the weight and slow decay present in reality.

Does the bass at large concerts sound slow? Well yes. There was nothing notably tuneful or fast about the bass at another Mr R. Williams' concert in the San Siro. Massive leading edge attack and dynamics (no doubt help by firing across, rather than along the stadium :rolleyes: ), but there was nothing that could be described as tight or fast.

As you say, any method of construction that allows less cone movement is closer to the ideal of adding less of it's own contribution to this ringing effect, nevermind the benefits of the lower distortion resulting from a cone remaining within the most linear part of it's travel.

Control of the enclosures resonance can ideed blur the leading edge, robbing impact. I seem to recall a test where the XLS-200 was able to push itself so hard, the output from the enclosure actually became audibly significant. Forgivable at £300 and probably advisable to spend more if you're going to run a sub like that flat out.

The art of the budget sub is to somehow extract this quart performance from the proverbial pint pot and balance the compromises along the way. Of all the comfortably sub £1k, compact subs I've heard, the SB-12 has impressed me most in this respect.

It should be noted that anyone finding it a bit weighty for their liking, can always turn the room compensation control toward one of the smaller room settings. This would lean it off nicely for music. Now where have I heard of a control similar to that.:wink:

Russell
 

Helicon

Banned
5ms delay on the lipsync on my projector drives me nuts, so I believe it's a perceivable difference, however subjective
And there was me thinking i was a freak.......and the only one at that :)
 

micb3rd

Established Member
I was thinking along the lines of a 20Hz signal takes four times longer to build to full SPL than, for instance, an 80Hz signal.

Russell


It i'm pretty sure does not work like that at all though, it only takes few cycles before a sine wave is up to full strength on a subwoofer driver, frequnecy does not change how fast the note is played.

The enclosure size and type will alter group delay. Group delay actualy makes little difference to under 30 hz as we can't realy detect any difference if it is small or big under that point.

There are plenty of low tuned subwoofers out there with quite a bit of group delay in the 20-25hz region but we can't hear it as it does not cause a problem in the area, this (as well as extension obviously) is one of the reasions why low tuning is good compared with 35-50hz tuning where high group delay can be maddening.
 

AngelEyes

Distinguished Member
Interesting stuff, I love listening to the boffins go on :thumbsup:

Adam
 

Nimby

Distinguished Member
My earlier points were made in the light of my IB experience. Where very deep bass from large organ pipes can tiptoe as nimbly ;) as a ballerina on the infrasonic icebergs jumbling beneath them.

There is often a sense of massive (acoustic) weight lifting and falling instantly and effortlessly. An acoustic antigravity device where asteroids can be made to collide and part again in the briefest of moments.

This effect is quite unlike any other subwoofer I have heard to date. A very short but very deep bass sound can be heard to rise, sustain and decay in an instant.

The cones of subwoofers with smaller divers must move piston-like before any sound can be produced. The linear distance must increase rapidly with falling frequency and increasing SPLs. The small cone simply cannot move enough air as frequency falls and volume demands increase.

The cones of subwoofers with many large drivers do not move visibly to produce very deep bass at very high spls. The IB and other large multiple driver subwoofers make a mockery of the idea that deep bass is slow. There is no substitute for a large radiating area. I'm sure the big Genelec's 7073A are not considered slow by their users.

Equalisation should speed up the bass from a conventional subwoofers in typical domestic room sizes. Room modes are probably responsible for more listener's perceptions of slow bass than the subwoofers themselves.

Failing the funds or space required for large subwoofers then multiple examples of any good smaller subwoofer should add perceived depth without loss of speed.

The combination will not reach any lower than any single subwoofer but will tend to lift the lower bass relative to the higher frequencies. Distortion will also fall with each new addition to the stack while available headroom will rise.

On reputation alone a stack of SVS SB12+s would no doubt bring a smile to the face of the owner when looking for bass speed. Matching the furnishing requirements of a domestic room with many small subs would not hold the same terrors that a single large bass coffin might.
 
D

dwain100

Guest
From a purely engineering point of view, if we inject a pulse into a sub and measure the transient response we should see something that replicates that pulse. If this is fairly accurate we can conclude that the Q has been designed well for that particular sub system and consequently the system should follow the input reasonably well - the response will follow the pulse as closely as possible with very low settling times (settling time/overhang which is present in vented systems more than sealed or IB because of the increased complexity of design when adding a tuned output with a time delay). If this is the case along with a small group delay the sub will be accurate and bass frequencies should be deep and fast.

If people can hear a delay from the higher frequencies to the lower in a struck note then this is probably real, its probably in the recording.
 

Nimby

Distinguished Member
Blanket statements regarding ported enclosures must always be couched in terms which allow for the size of the subwoofer involved.

There is a type of very large reflex enclosure which seem to be providing startling results at the expense of great size. Call them Sonosobs or LLTs they still seem to work.

Perhaps there lies the ultimate weakness of all small subs? They simply cannot move sufficient air to match the physics.

One can use small, fast, reciprocating pumps to move air rapidly enough to achieve reasonable results. But air rushing around the pipework and inevitably small cavities cannot flow as easily or as smoothly as that in a more suitably proportioned system.

The usual analogy is that of the big V8 motor versus the turboed screamer. Large subwoofer drivers have the effortless torque required to accelerate large quantities of air without making a highly turbulent fuss about it.

Thousands of years of acoustical musical instrument development has not replaced the bass instruments with a hand-sized object. A bass drum is not yet smaller than a snare drum. A bass sax is not yet smaller than an alto. Large still goes with the territory of producing deep bass in a realistic fashion.

Marrying this need for great size with realistic domestic situations is still some way down the road of subwoofer development.

Just imagine if every child had to take one of these to their recorder class!

subcbkd2.jpg
 
D

dwain100

Guest
Blanket statements regarding ported enclosures must always be couched in terms which allow for the size of the subwoofer involved.
subcbkd2.jpg

Right on, read original statement;)

'(settling time/overhang which is present in vented systems more than sealed or IB because of the increased complexity of design when adding a tuned output with a time delay)'
 

HiFiRuss71

Distinguished Member
So, we're agreed then.:thumbsup:

As the smallest sub, with the biggest cone, in a sealed box within the OPs budget and benefiting from EQ to tighten the rooms response, the SB-12 is probably well worth a look as a good example of the trade offs on offer.

:lease:

Russell
 

Helicon

Banned
So, we're agreed then.:thumbsup:

As the smallest sub, with the biggest cone, in a sealed box within the OPs budget and benefiting from EQ to tighten the rooms response, the SB-12 is probably well worth a look as a good example of the trade offs on offer.
As my previous recommendation, the M&K KX12 is a very similar size sealed box with the same size cone :)
 

HiFiRuss71

Distinguished Member
Ye gods! Somewhere along the line, we've informed someone? Standards are obviously dropping!;)

The only thing I was left thinking was, 'She's a musician and therefore poor. How does she fit that on a bus?':)

Russell
 

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