Subs

XTZ do a sub for £300 but it's only 8" their 12" subs start from £440.

I've owned BK subs before and they are very nicely made, I've also visited the factory and they are nice people.
 
agw_01 said:
While we're on the subject of BK subs where they don't have a high level pass through for the speakers, how would you filter bass frequencies away from the main speakers?

I'm running a NAD stereo amp to power my front speakers and obviously any crossover between the source and the amp, or between the pre/power sections is going to cut these frequencies to the subwoofer as well. I run the sub high level from the speaker outputs on the NAD.

@theone8181, if you're looking at BK, definitely check out the collosusxb outlet store on ebay. You could save yourself a considerable amount of money.
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Lots of subs use the same sort of parallel connection method that BK use for its High Level connection. It relies on the natural roll-off of the main speakers.

This means that the sub is blending in where the main speakers tail off rather than actively reducing the frequency range of the mains.
 
I can understand why they do it like that lucid, and it definitely makes sense for integration purposes. I've seen many subs that have high level in and outputs, where the subwoofer's internal crossover would affect the frequencies which were then fed to the speakers.

My main speakers are pretty strong in the low end and when pushing them hard, I could always hear when the drivers were starting to work a little too hard and would adjust the volume accordingly. I don't seem to get the same feedback since installing the sub so am looking to roll away sub 50Hz stuff to the subwoofer, mainly to reduce any risk of damage to the speakers.
 
Yeah you can that that, with a high pass filter. Either in a sub like the svs SB 12+ that has high level screw down terminals in/out. Or with the ultra which have high pass on low level (unsure if it has high level) the ultra has adjustable high pass rather than fixed. The sb12+ has fixed high pass at 80hz.

The outlaw ICBM-1 I have is low level you put it in between your pre and power amplifiers. One set of outputs go to your l/r poweramps and they receive greater than high pass switch, or full range of you set to that, and the sub receives lower than high pass switch.

It worked well with stand mount and sub setup. Basically it is bass management like your typical avr in the analogue domain. It also has benefits that it frees up power and have a cleaner midrange signal.

If you can get a outlaw ICBM-1 and it'll work in your system it's worth it.
 
Is the Gemini 2 still worth considering compared to the XXLS400? I'm after a sub too but have a smaller budget to the OP.
 
maj said:
Is the Gemini 2 still worth considering compared to the XXLS400? I'm after a sub too but have a smaller budget to the OP.
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The XXLS400 is a lot bigger and far more powerful, so it should be better. After all, it's double the price.

"Is the Gemini II worth considering? " ...... In a word, Yes. Here's why:

It shouldn't come as any surprise that if you want huge levels of subterranean bass then you need to get big and expensive. As Scotty from Star Trek said 'Yea cannae change the law of physics' or something like that. The bottom line is that there's no cheap get around with this. Where budget or space are limited, then some compromises have to be made.

Sunfire subs and REL showed it was possible to get fairly deep bass from a small cube subwoofer fitted with a 10" driver. They each had long throw drivers and a lot of power. The REL Q200 was about 1 cubic foot in size and packed a really well-made 400W amp. As a result, it could get down to around 20Hz. The rub was the cost. It was around £600 IIRC.

When the design budget gets cut down then something has to give. The first thing is usually the finish. Wood veneer is expensive. Vinyl wrap is cheaper. Next, it's the amp power and driver quality. Not all 10" bass drivers are equal; BK shows exactly this with the difference between the Gemini II and its similar-sized sibling, the XLS200. For the extra £100 or so, it has a better driver and a bit more power compared to the Gemini II. As a result, it goes a little louder and digs a little deeper.

One big design decision is whether to go ported or stay with sealed box. On paper, it seems like a simple choice. Bookshelf and stand-mount designers pretty-much abandoned the sealed box (Infinite Baffle) design for ported (Bass Reflex) designs in the 80's because it provides more bass and a more efficient speaker. Surely then, all budget subs should go the same way? But they haven't, so there must be a reason why porting doesn't always work so well for subs.

The problem is decoupling.

If you haven't come across the phrase before then it sounds a bit dramatic, like something is coming apart. It's not quite that bad. What decoupling means is the frequency below which the driver and bass reflex system are no longer working together. The bass driver moves a lot - to the point where if the volume is loud enough then it will hit the end stops of its travel and produce a buzzing or flapping noise. That's bad. It's the sound of the driver destroying itself. The frequency that this starts to occur depends on the size- and the design of the driver.

Now let's pull at the above together and look at a common alternative choice to the Gemini II; the Wharfedale SW150.

Before I carry on, let me first say that Wharfedale makes good speakers, and unlike many other competing brands, the company even makes it's own sub amps in-house rather than buying in from 3rd party suppliers. I'm not sure if that's still the case with the 150, but it is a mark of how seriously the company takes quality control. What follows then isn't me knocking their sub, it's simply highlighting some of the important design and performance limitations of entry-level bass ported subs in general.

The SW150 is marginally larger than the Gemini II. Both use a 10" driver and, IIRC, are roughly the same power. To save cost, Wharfedale went with a vinyl wrap finish. Other than bass porting, the other significant difference is that Wharfedale sells through a retailer network where as BK sells from the factory gate. If you want to think of that in simple terms, then Wharfedale allows the dealers to make a profit, whereas BK uses that money to pay for some better components and a nice wood finish.

To be fair to Wharfedale though, the SW150 was originally launched over a decade ago to sell at £250, but you'll now pick one up for under £180. I've no idea whether that's purely dealers cutting their throats to compete or if its partly Wharfedale capitalising on some in-house economies to get a lower trade price.

The nitty gritty is that the Wharfedale will go louder in absolute terms, but that's like saying this car has a higher top speed than that one. In everyday driving we don't use the maximum speed of our cars, so what's the benefit? It's the same with the subs. The ported design of the SW150 will benefit more from corner placement (boundary effect) to boost the bass output too, but that also means ported designs need more care in room placement. Sealed subs are a little less fussy about where they live. In theory, the SW150 should go a tad deeper being ported. In practice you won't hear more bass depth, but probably will hear the sub booming a bit more noticeably because of boundary effect. The Gemini II will sound cleaner, but that can also be misinterpreted as having less presence.

Neither sub is going to be able to fill a large room with foundation-shaking bass, or make much in the way of bass contribution if you have three foot tall floorstanders with 6" woofers. That's not because they're no good. It's simply a limit of cost when it comes to the driver and the amp power. Both subs will get down to 40Hz or a bit lower. If you want to get deeper than that and the budget won't stretch beyond the Gemini II, then you need to be looking at second-hand. Check out Ebay. There's a REL Q200 going with some Mordaunt Short speakers as a package as collection only from Wigan. Ebay item 232923267822. The sub could do with refinishing by the look of it, but as it stands the whole package is under-valued at its Buy-it-Now price of £200.
 
I'll add to above but as for frequencies outputting below the native port tune of the cabinet and causing excesive cone movement, distortion, port chuffing, driver bottoming out, this can be sorted by these...in order of preference

1) having a sub sonic filter set to the port tune. With a sub having port tune of 20hz, have a sub sonic filter at 20hz. It's the same principle as a record player anti thump filter.

2) have a sub with a very low port tune. This may help but typically you will lose higher max output. Ie if you had two subs tuned to 20 and 25hz the 25hz model will able to play several db louder. But the 20hz will reach lower.

3) have more than one sub, this'll mean the one sub will be playing several dB lower. I would still have a sub sonic filter though.

When I ported mine to 11hz was quite interesting the physical feeling, but I settled with 16hz port tune as room was small.

I would always have a sub sonic filter with a ported sub. Last time I had a rel ported sub it was bottoming out all the time, but with my first ported sub with sub sonic filter a svs pc plus 12 I could really blast it out at way above reference levels it never had the bad sound of the rel when the rel reached its limit. Which meant it could play cleaner with less distortion at any volume.

Buy the best sub you can. If it was me looking at bk line it'lll either be bk xls400 for a stereo system, or duals for the cinema, or bk monolith +. Personally though living witb the ultra 13.5 don't think settle for a normal sub in the main AV system. Currently use 12" svs sealed in music system. But find out if monolith have sub sonic filter, if not get a antimode and this does have one. For sealed you don't need a sub sonic filter.

I personally would stick with svs though. Unsure what I'd go with either sb or pb 4000 or SB or pb ultra 16. Duals. Now have much bigger room so ported may be better however the pb boxes are massive. Happy with my SB ultra 13 so if I find another one going cheap I'll get another.

The svs 4000 and ultra models have a few useful features like variable high pass, room compensation, peq. New ones have mobile phone control which seems a gimmick - unless you can do the peq from that maybe with some kind of graph that would be cool.
 
hornetstinger said:
I'll add to above but as for frequencies outputting below the native port tune of the cabinet and causing excesive cone movement, distortion, port chuffing, driver bottoming out, this can be sorted by these...in order of preference
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The svs 4000 and ultra models have a few useful features like variable high pass, room compensation, peq. New ones have mobile phone control which seems a gimmick - unless you can do the peq from that maybe with some kind of graph that would be cool.
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That's all very well, but can any of it be achieved for a budget of around £220 including the sub?

@maj said he (?) has less to spend than the OP, and the OP's budget is £300. How then is it helpful to talk about subs at £450+ (XXLS400 & Monolith) plus the cost of additional processing? As for your SVS recommendations, you do realise that a new PB4000 is over £2000, right?

I'm not saying that the ideas aren't interesting, or that they can't be discussed. But wouldn't it be better to talk about solutions with sensible reach of the enquirer's budget? Try to keep it relevant to what the enquirer needs rather than diving off in to flights of fantasy.
 
If the XLS400 is a bit too much, you could look at the P12-300s, there are two models now I believe.

I got one from the grade b ebay shop someone mentioned, again no damage at all and the gloss finish looks great, was just over £300 if I remember rightly
 
I'll just remind you that the BK Gemini II isn't ported. We'll let that sit there for a moment.

Now then, back to ported subs; why don't you put some meat on those bones? Price up what you think is a worthy sub and the subsonic filter. Remember, the total budget is £220 new. Away you go. Oh, and remember too, this should be an all-round sub; movies and music.
 
Budget subs are typically ported as don't need as much power to get same SPL.

Determine a gemini will be able to fill your room it is only a small driver low powered amp. It'll be fine for music but in a large room for action movies you probably need a better sub.

Also depending on your speakers you want a sub that teaches way lower. If you have decent sized floorstanders and budget sub may only play a few hz lower. Some ported models.xod be ported to 40hz to get as much volume as possible good speakers will reach under that.

Svs have a couple of budget subs pb 1000 and SB 1000.
 
hornetstinger said:
Budget subs are typically ported as don't need as much power to get same SPL.

Determine a gemini will be able to fill your room it is only a small driver low powered amp. It'll be fine for music but in a large room for action movies you probably need a better sub.

Also depending on your speakers you want a sub that teaches way lower. If you have decent sized floorstanders and budget sub may only play a few hz lower. Some ported models.xod be ported to 40hz to get as much volume as possible good speakers will reach under that.

Svs have a couple of budget subs pb 1000 and SB 1000.
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You're avoiding the question.

The budget is £220 and your challenge is to find something more capable than a Gemini II and include a subsonic filter at the price.


Oh, and while we are here, the PB1000 and SB1000 may well be budget by SVS standards, but they're each still in the £500-£550 price range even from retailers who offer big discounts. Once again, you're suggesting stuff way way out above the enquirer's budget.
 
Well that question opened a can of worms :p but thanks for all the replies. Some very useful information to consider and I will look into the alternatives mentioned as well as B-Grade. I don't have the biggest of living rooms so size is a factor (13'0'' x 11'6'') and the Gemini 2 would fit nicely in one corner of living room based on its dimensions. Just looking for something to compliment my Q2020i's but will take on board the advice regarding it isn't that great for movies.
 
Since you have standmounts you want a good sub so it plays well in higher frequencies. With this I choose sealed.

Personally I would try stepping up from Gemini to bk xls200, xls400 or svs 1000 or 2000.
 
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maj said:
Well that question opened a can of worms :p but thanks for all the replies. Some very useful information to consider and I will look into the alternatives mentioned as well as B-Grade. I don't have the biggest of living rooms so size is a factor (13'0'' x 11'6'') and the Gemini 2 would fit nicely in one corner of living room based on its dimensions. Just looking for something to compliment my Q2020i's but will take on board the advice regarding it isn't that great for movies.
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Just to give some practical information you might find useful. From a total amateur.

I have a BK Gemini II sub with Q Acoustics 2050i fronts, 3090 centre and 7000LR for surrounds.

Watching the final airport scenes of Heat on Blu-ray the other night, I didn't ever think I needed any more oomph from my sub woofer. I could feel every plane landing, let alone hear it.

Music sounds great too.
 
barmyllama said:
Just to give some practical information you might find useful. From a total amateur.

I have a BK Gemini II sub with Q Acoustics 2050i fronts, 3090 centre and 7000LR for surrounds.

Watching the final airport scenes of Heat on Blu-ray the other night, I didn't ever think I needed any more oomph from my sub woofer. I could feel every plane landing, let alone hear it.

Music sounds great too.
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Best not to go and demo a high end sub then.

I think my SB ultra lacks something what the pc ultra 13 did have for movies, pressure waves. Sauron ring drop and explosion good example. Ported model pressurises the room, makes the room floors flex.

I've moved from a cheap sub to a pretty good one and it's been a big step between the models I'd you are into action movies it really is worthwhile getting a good one.

For music don't need to go mad but need a good fast sure not boomy,.just to supplement the mains. For.movies supplement mains too but have ability to make it feel like what is happening on screen is real. Ie grenades going off.
 
barmyllama said:
Just to give some practical information you might find useful. From a total amateur.

I have a BK Gemini II sub with Q Acoustics 2050i fronts, 3090 centre and 7000LR for surrounds.

Watching the final airport scenes of Heat on Blu-ray the other night, I didn't ever think I needed any more oomph from my sub woofer. I could feel every plane landing, let alone hear it.

Music sounds great too.
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All the BK subwoofers are very good for the money.

I have the XXLS400 and I always wonder how good the monolith must be.

However XXLS400 is better for music and is an all rounder. The Monolith is more for movies and can't handle the fast pace of music. so I think I made the right choice as I listen to a lot of music too on the AVR.
 
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