Recomendation for Subwoofer Driver

[s162216]

Hi,

I am building a subwoofer for my computer with a 15W RMS amplifier and I need some recomendations for what driver I should use for my requirements and is in my price range

These are:

Costs max £65 and is avaliable in UK
Can go down to 30hz or below if possible with an internal sealed enclosure volume of up to 3.6 cubic feet/102L. Must also have a Qtc value of 0.7 with this volume
Is up to 15 inches/ 380mm

The closest I have found so far is the Audiobahn Dub 200 which can go go down to about 34hz with an internal volume of 2.8 cubic feet.

 

[WmAx]

Hi,

I am building a subwoofer for my computer with a 15W RMS amplifier and I need some recomendations for what driver I should use for my requirements and is in my price range

These are:

Costs max £65 and is avaliable in UK
Can go down to 30hz or below if possible with an internal sealed enclosure volume of up to 3.6 cubic feet/102L. Must also have a Qtc value of 0.7 with this volume
Is up to 15 inches/ 380mm

The closest I have found so far is the Audiobahn Dub 200 which can go go down to about 34hz with an internal volume of 2.8 cubic feet.

Why only 15 watts? Especially in sealed, this is a ridiculous. If you will use a ported alignment, then you can reach your desired roll off point, and with some useful SPL for very nearfield low volume listening with the 15 watts. Ideally, you will use a pro-sound driver with very high sensitivity. This would get you very considerable SPL even with just 15 watts. The very limited x-max on pro-audio woofers will not be a problem for you considering the sub amp power.

-Chris

 

[T2T]

Why only 15 watts? Especially in sealed, this is a ridiculous. If you will use a ported alignment, then you can reach your desired roll off point, and with some useful SPL for very nearfield low volume listening with the 15 watts. Ideally, you will use a pro-sound driver with very high sensitivity. This would get you very considerable SPL even with just 15 watts. The very limited x-max on pro-audio woofers will not be a problem for you considering the sub amp power.

-Chris

Quite true. 15 watts for what's desired is sort of like trying to run a Ferrari with an engine from a scooter. Some things just aren't meant to be.

 

[s162216]

Actually 32W RMS not 15

I am building the amplifier myself and the site where I had got the circuit diagram from incorrectly said it would put 32W into 8 ohms and from that I deduced that it was about 15W RMS. However I looked at the datasheet for the amplifier IC and it actually is 32W RMS into 8 ohm and up to 50W RMS for 4 ohm. This is for my bedroom anyway so its not exactly going to need to be too loud anyway as the rooms not really that big to need 80W RMS or something.
The main reason that I want a sealed enclosure is because this is my first sub that I am actually planning to build and they are simpler than ported enclosures.
I have found the MAD1259 driver which with a bass boost would give me even better than my desired performance (this gives about 22hz with 3.6 cubic feet internal volume), but at $150 with the rubbish dollar to pound exchange rate at the moment its about £40 outside my price range.

 

[WmAx]

I am building the amplifier myself and the site where I had got the circuit diagram from incorrectly said it would put 32W into 8 ohms and from that I deduced that it was about 15W RMS. However I looked at the datasheet for the amplifier IC and it actually is 32W RMS into 8 ohm and up to 50W RMS for 4 ohm. This is for my bedroom anyway so its not exactly going to need to be too loud anyway as the rooms not really that big to need 80W RMS or something.
The main reason that I want a sealed enclosure is because this is my first sub that I am actually planning to build and they are simpler than ported enclosures.
I have found the MAD1259 driver which with a bass boost would give me even better than my desired performance (this gives about 22hz with 3.6 cubic feet internal volume), but at $150 with the rubbish dollar to pound exchange rate at the moment its about £40 outside my price range.

32 watts is barely better than 15 watts. I stick to my last reply.

I will gladly help you with the details of a ported system. It's not nearly as difficult as it might seem.

-Chris

 

[s162216]

Ok

32 watts is barely better than 15 watts. I stick to my last reply.

I will gladly help you with the details of a ported system. It's not nearly as difficult as it might seem.

-Chris

O.K if I am to build a ported system, what driver would you use and will the internal volume be about the same or less as 3.6 cubic feet is really pushing it to be honest as 18mm MDF in the UK is quite expensive.

 

[sploo]

Hi,

I can't advise on a suitable woofer - but FYI: A 125 liter box could be made from a cube with internal dimensions of 50cm (50cm cube = 50^3 = 125000cm^3 = 125L).

Assuming this is a bit bigger than your requirement (i.e. you could get away with external faces of approx 50cm x 50cm) then a standard 8'x4' sheet of 3/4" MDF (approx 2440x1220x18mm) would yield eight such squares, with plenty to spare. As you obviously only need six faces, that would leave lots of material for making internal braces.

Some branches of Focus DIY have 8'x4' sheets - usually less than 20GBP. Travis Perkins tends to be more expensive, but the last time I looked, a sheet was around 26GBP. Avoid 4'x2' sheets, as you tend to pay a big premium for them, but you will need a van, or a store that will saw the panels, as 8'x4' and a family car won't go.

 

[WmAx]

O.K if I am to build a ported system, what driver would you use and will the internal volume be about the same or less as 3.6 cubic feet is really pushing it to be honest as 18mm MDF in the UK is quite expensive.

Please direct/link me to the U.K. driver retailers that you have available so that I can see what options you have. I presume you do not intend to import from a U.S. retailer, and the available products can differ between us. Also, please include U.K. pro audio retailer that carry raw pro audio/pa drivers. Because the best option for you is most likely a 15" pro audio woofer. These have very high sensitivity, and 32 watts could potentially be sufficient for any purpose you have with the right design.

-Chris

 

[s162216]

Driver Retailers and found better Amp

Please direct/link me to the U.K. driver retailers that you have available so that I can see what options you have. I presume you do not intend to import from a U.S. retailer, and the available products can differ between us. Also, please include U.K. pro audio retailer that carry raw pro audio/pa drivers. Because the best option for you is most likely a 15" pro audio woofer. These have very high sensitivity, and 32 watts could potentially be sufficient for any purpose you have with the right design.

-Chris

Here are some places that sell subwoofer drivers, most are generally for cars.

http://www.audioassault.co.uk/
http://www.maplin.co.uk/Search.aspx?menuno=11967 (Similar to Radio Shack)
http://www.overstock.com/
http://www.alphacaraudio.co.uk/

I have found some places that sell professional audio stuff

http://www.classd.ltd.uk/home.php
http://www.lean-business.co.uk/eshop/
http://www.e-av.co.uk/index.php
http://www.jhs.co.uk/intro.htm


Also I have found a 6 channel amp designed for a car for £49.00 that can put 95W RMS into 2 ohm, 50W into 4 ohm and about half that into 8 ohm. From this 4 ohm would proberly be the best as I don't need a system with 95W, it would be too loud for my room.
The reason I need this is because this subwoofer is due to be part of a complete 5.1 surround sound system for my PC with a Tannoy Mercury centre speaker and bookshelf speakers. If you want to know the amp is the Beat Audio Evolve B4.100.
I am not buying anything too expensive as I have set myself a budget of £350. The lower the price of the driver the better as I would like to keep the total cost under £100 including the wood etc.

 

[s162216]

Other vendors

Have also found some drivers here:

http://www.solotechnic.co.uk/c.do?category=174&page=3

The problem is that all these seem to be 8 ohm and it would be better if it was 4 ohm as it will then be louder than the centre, surround and front stereo speakers.

 

[s162216]

Forget about 4 ohm requirement

It does not matter if the speaker is 4 or 8 ohm as I have worked out that for about £10 I can get a suitable impedence matching transformer that will allow the full 95W that the 2 ohm can output into an 8 ohm speaker.

 

[s162216]

Best 4 ohm yet

Have found the Pioneer TSW2575 here http://shop.audioimages.co.uk/pioneer-ts-w257f-25cm-subwoofer-p-778.html There are also quite a number of other drivers there as well.

It is 10", but has a sensivity of 92, a frequency range of 20 to 2500 Hz and best of all it is 4 ohm so I can put 50W through it. There is a similar driver which is 12" but it only has a sensivity of 90.