First, some good news....
Your CEOL Piccolo N5 has a dedicated subwoofer output socket (RCA phono) on the bottom right of the rear panel. That oppens up your subwoofer choices because a lot of entry-level subs only have this as a connection socket.
Now, some not so good news....
£100-£150 (presuming new) won't get you a nice sub for music.
As with most consumer goods, there a minimum-spend threshold to get past just to get decent build and performance. If you work the price back by taking off VAT, retailer's margin, distributor and manufacturer margins, support costs, transport costs, corporation tax etc etc then the £100-£150 sub might have a cost to manufacture for labour and materials of around £30 to £50. That can be quite a sobering thought. It leaves the designers with some very hard choices.
In the case of a budget sub it's compromises over materials, cabinet thickness, construction, type of sub (sealed vs ported), finish and so on. These choices translate to lighter (flimsier) cabinets covered in vinyl wrap which saves a big chunk of cash. There'll be less internal bracing so the cabinet resonances won't be as well controlled, this then feeds in to the accuracy of the sound. The driver choice will look okay on paper, but aspects such as efficiency and compliance will have been compromised to hit a price point. The sub's amp plate won't have much in the way of power reserve over the quoted output since the manufacturer will want the biggest headline power figure for the least $$$'s of production budget.
The bottom line then is your typical £100-£150 sub is designed for the movie market rather than for music lovers. Priority will be give to bass volume/slam by using a ported design to get the best bang per Buck. Compared to a sealed sub, ported designs at entry-level prices can sound a bit slow and one-notey.
Back to the good news....
It doesn't take much to turn things around.
Cutting out the retail element by selling direct from the factory makes a massive difference to the value that a buyer can achieve. BK Subs does exactly that. They sell direct, so there's a big chunk of costs cut from the equation. That means more money goes in to the product and you the customer get a better sub as a direct result.
You still won't hit £100-£150 new, but at £225 direct from the factory, the BK Gemini II sub is impossible to beat for build quality and performance.
This is a 10" sealed sub with a genuine 150 Watt amp. The footprint is very compact. It's also a sophisticated sub in that it has both a line level (RCA phono) and a speaker level connection so it's a good partner even for simple stereo Hi-Fi amps. These are potent little subs that do music beautifully and make a decent stab at TV/movie audio bass playing through your CEOL or an AV receiver too.
BK subs come up for sale in the secondhand market as owners get bitten by the bug and upgrade. Gemini II typically change hands for around £150 used in the basic wood veneer finishes.
Looking at alternatives, Richers have the ELAC S10 Debut at £150. It's also 10", and although they have it as a clearance deal, I wouldn't consider it a worthy competitor to a Gemini II. It has all the compromises of a budget movie sub. It's undoubtedly better than the £100 Yamaha sub which is their next cheapest offering, but still compromised by it price/performance ratio.
