Diy active sub kit or building from plans?

[Vil]

Hi folks, I would love to build quality acitve sub with 10 to 12” driver. For me it would be easier getting full kit but I’m also open to building from plan. The only issue for me is building the amp, unless I could buy a ready made one. I can build cabinet no problem.
This would be used mainly for music. Any advice appreciated. Thanks

 

[lovinthehd]

I use pro style amps (Crown XLS) on my diy subs (don't want the amp built into the sub), but plate amps are available if you want it as part of the box. I wouldn't try to build a plate amp, but some of the class D module kits might not be too bad to assemble. Unless you model your own sub box, I'd go with someone's plans that has done so. If you want to model your own you can download software like winisd or bass box pro (think you have to pay for the latter, tho). What do you plan to build the box with, mdf or baltic birch?

 

[Vil]

Thanks for quick response, first of all, yes the cabinet would be from mdf. I just don’t have much experience building these guys, so when it comes to what volume, what driver, what amp, sealed, ported…that’s where I’m lost. That’s why I need to follow some proven designs.

 

[lovinthehd]

Have you located any here to utilize? I thought we had a master thread listing various builds but I'm not seeing it. diyaudio.com and avsforum.com might be places to check as well. When it comes to amp that will somewhat depend on driver and design and many will mention what amps they're using with a given build. FWIW I built mine from baltic birch to save weight and less toxic dust.

 

[Vil]

Thanks heaps for the info, will check other sites as well

 

[TLS Guy]

Thanks heaps for the info, will check other sites as well

What is your budget, and what size of sub are you looking for in terms of volume and foot print?

I have quite a few designs on my website, but I have designed subs for members here. Subs are much easier than other speakers to design, and the models are very accurate for subs. So when you look at the model you know how it will work.

 

[Alex2507]

I have quite a few designs on my website

Link please ... ?

Then you can get back to convalescing.

 

[Vil]

What is your budget, and what size of sub are you looking for in terms of volume and foot print?

I have quite a few designs on my website, but I have designed subs for members here. Subs are much easier than other speakers to design, and the models are very accurate for subs. So when you look at the model you know how it will work.

Hi TLS guy, I’m thinking 10 to 12 inch driver with plate amp. I have a small room with Dali Oberon 3 bookshelf speakers but I feel it needs sub for bass extention. I was hoping up to $600. I can build cabinet for minimal cost. I can also be flexible but I know if it’s going to cost more, I could skip building and buy already made one.

 

[TLS Guy]

Hi TLS guy, I’m thinking 10 to 12 inch driver with plate amp. I have a small room with Dali Oberon 3 bookshelf speakers but I feel it needs sub for bass extention. I was hoping up to $600. I can build cabinet for minimal cost. I can also be flexible but I know if it’s going to cost more, I could skip building and buy already made one.

What size of cabinet are you able to tolerate? A vented design will be much easier, and cheaper, but cabinet size will be larger.

 

[Vil]

What size of cabinet are you able to tolerate? A vented design will be much easier, and cheaper, but cabinet size will be larger.

Good question, to be honest I’d prefer if it was smaller 300 to 350mm square box, perhaps sealed unit would be better option. I understand it may be pricier but if the quality matches commercialy made ones why not give it a go. Just how much more expensive would it be?

 

[TLS Guy]

Good question, to be honest I’d prefer if it was smaller 300 to 350mm square box, perhaps sealed unit would be better option. I understand it may be pricier but if the quality matches commercialy made ones why not give it a go. Just how much more expensive would it be?

That is a very small sub. There is a saying in speaker design, which says: - "Does a speaker have to be large? No but it really, really helps."

Then there is Hoffman's Iron man's law, which basically says that the smaller the speaker the less sensitive it will be, especially in the bass.

So at your specified volume that commits you to a sealed design. There are very few drivers available that can produce a sub in that volume. Because of the volume of the construction materials, the driver volume, bracing and plate amp volume you are looking at an internal air volume of under 1 cu.ft.

Now in a sealed enclosure the output is going to be dropping above the last octave. So that requires a driver with a massive motor system that can take the power required to force output below the Fs of the design. That is the frequency at which output is 3db below reference. Below that point the driver has to be able to take a boost at 12db per octave. For every 3db of boost you have to double the amp power. In order to prevent damage to the driver, you need a high pass filter to cut the driver output at the point the driver exceeds it maximum excursion, known as x-max. Now in such a design the internal air pressures are enormous, and so that cabinet has to be extremely rigid with figure of 8 bracing. Extreme rigidity is called for. The driver will need rolling off at 26 to 27 Hz range. I will know more if I do a model, but I don't want to spend time on that, unless this design truly appeals to you.

Now there is a driver that could be used in a design to your specification. It is a Dayton Audio 10" Ultimax sub driver. It is robust enough to handle the power.

The driver and a suitable plate amp will set you back $509.00



By the time you have built that cabinet and finished it you will be at the top end of you budget, and likely a little over.

So, if you think this is the way to go, then I certainly could model it, and come up with a design.

However, in terms of performance it will not come close to competing with a much larger ported design.

 

[Vil]

That is a very small sub. There is a saying in speaker design, which says: - "Does a speaker have to be large? No but it really, really helps."

Then there is Hoffman's Iron man's law, which basically says that the smaller the speaker the less sensitive it will be, especially in the bass.

So at your specified volume that commits you to a sealed design. There are very few drivers available that can produce a sub in that volume. Because of the volume of the construction materials, the driver volume, bracing and plate amp volume you are looking at an internal air volume of under 1 cu.ft.

Now in a sealed enclosure the output is going to be dropping above the last octave. So that requires a driver with a massive motor system that can take the power required to force output below the Fs of the design. That is the frequency at which output is 3db below reference. Below that point the driver has to be able to take a boost at 12db per octave. For every 3db of boost you have to double the amp power. In order to prevent damage to the driver, you need a high pass filter to cut the driver output at the point the driver exceeds it maximum excursion, known as x-max. Now in such a design the internal air pressures are enormous, and so that cabinet has to be extremely rigid with figure of 8 bracing. Extreme rigidity is called for. The driver will need rolling off at 26 to 27 Hz range. I will know more if I do a model, but I don't want to spend time on that, unless this design truly appeals to you.

Now there is a driver that could be used in a design to your specification. It is a Dayton Audio 10" Ultimax sub driver. It is robust enough to handle the power.

The driver and a suitable plate amp will set you back $509.00



By the time you have built that cabinet and finished it you will be at the top end of you budget, and likely a little over.

So, if you think this is the way to go, then I certainly could model it, and come up with a design.

However, in terms of performance it will not come close to competing with a much larger ported design.

Thanks for explaining this. Sorry for asking dumb questions I just had no idea what’s required and how this all works. Roughly, how big the cabinet would have to be using the above mentioned Dayton driver? Still, would prefer having the width no more than 350mm but can play with depth and height in order to obtain adequate volume. Just curious, that would be for vented type..correct?

 

[lovinthehd]

Why the particular width limit?

 

[Vil]

My original idea idea was to save space, since my room is quite small. I didn’t know, these diy subs need to be as big as cupboards. I don’t think I need earthquake simulator.

 

[lovinthehd]

Subs can get fairly large and heavy, if you want.

I was more curious if you only had one location in mind, and was curious why it was restricted to width rather than the other two dimensions. Keep in mind ideal sub location isn't always best where you might have in mind in advance to place it....

 

[TLS Guy]

My original idea idea was to save space, since my room is quite small. I didn’t know, these diy subs need to be as big as cupboards. I don’t think I need earthquake simulator.

I selected that driver based on your specs.

The bottom line is that a different larger and cheaper driver in a bigger box will work much better. Making a small sub like you requested is what I call a brutal design. It is brute force because you are fighting the laws of physics. I much prefer to work with the laws of physics. There is a reason a grand piano, tuba and bass drum are the size they are. Making a speaker less then I cu.ft. internal volume is fighting the laws of physics. Given enough power (brute force) it can be done these days, given the huge power these class D plate amps have made available.

I have attached a file of a design for a 12 driver optimal for a vented alignment that is much larger, but efficient and won't require all that brutal Eq. It would sound very good and have long term reliability. This is a design I already have on file.

If needs must I can design you that minute sub, but that very small foot print makes the design complicated and as I said brutal.

 

[Vil]

Hi TLS Guy, first of all, sorry for not responding for a while..(been away) and my head was elsewhere. I was looking at the above file you attached and I think it still might be a bit big. However, I really like the combo you sent me earlier.

CLEARANCE Dayton Audio UM10-22 10" Ultimax DVC Subwoofer 2 ohms Per Coil

Dayton Audio UM10-22 10" Ultimax DVC Subwoofer 2 ohms Per CoilDayton Audio UM10-22 10" Ultimax DVC SubwooferExperience the Apex of Subwoofer DesignThe Ultimax Series of dual voice coil subwoofers, from Dayton Audio, are not for the faint of heart. Built using the latest in subwoofer technology...

www.parts-express.com

Just a question, is this more suited for a sealed unit with the earlier stated dimensions or could I use slightly less powerful plate amp for a vented box? Also, if I chose this 10” driver for a vented option, how big the box would have to be for the right physics? I’m planning to use 3/4” MDF
I really appreciate your advice.

 

[TLS Guy]

Hi TLS Guy, first of all, sorry for not responding for a while..(been away) and my head was elsewhere. I was looking at the above file you attached and I think it still might be a bit big. However, I really like the combo you sent me earlier.

CLEARANCE Dayton Audio UM10-22 10" Ultimax DVC Subwoofer 2 ohms Per Coil

Dayton Audio UM10-22 10" Ultimax DVC Subwoofer 2 ohms Per CoilDayton Audio UM10-22 10" Ultimax DVC SubwooferExperience the Apex of Subwoofer DesignThe Ultimax Series of dual voice coil subwoofers, from Dayton Audio, are not for the faint of heart. Built using the latest in subwoofer technology...

www.parts-express.com

Just a question, is this more suited for a sealed unit with the earlier stated dimensions or could I use slightly less powerful plate amp for a vented box? Also, if I chose this 10” driver for a vented option, how big the box would have to be for the right physics? I’m planning to use 3/4” MDF
I really appreciate your advice.

That driver is optimized for a sealed alignment. A vented alignment would push the internal volume to 1.3 cu.ft. So it would more than double it.

 

[Alex2507]

That driver is optimized for a sealed alignment. A vented alignment would push the internal volume to 1.3 cu.ft. So it would more than double it.

Plus the port, right? That's still tiny.

Would you mind giving me the link to your design page/site thing?

I don’t think I need earthquake simulator.

It's not about the earth quakes. I've built a couple of vented subs designed by TLS. They sound amazing. A small sealed SVS sub that sold for ~$600 in comparison was no match for either design.


Mark,
The second design with the 10" RBH drivers finally made it into the living room HT where all the other subs had their try outs. The first design with the 10" JBL drivers got sold to an old friend and are currently simulating earth quakes.

Thanks again.

 

[TLS Guy]

Plus the port, right? That's still tiny.

Would you mind giving me the link to your design page/site thing?




It's not about the earth quakes. I've built a couple of vented subs designed by TLS. They sound amazing. A small sealed SVS sub that sold for ~$600 in comparison was no match for either design.


Mark,
The second design with the 10" RBH drivers finally made it into the living room HT where all the other subs had their try outs. The first design with the 10" JBL drivers got sold to an old friend and are currently simulating earth quakes.

Thanks again.

That driver really is aimed at the small sealed end of the spectrum and is a brute force driver.

Have you got an itch to build another sub? If so what are your aims and expectations?