Diy active sub kit or building from plans?

[Vil]

Thanks Alex and TLS, good to hear it's totally worth it. I'm now thinking of ditching sealed unit and go for the ported. Now, I can get SPA300 D plate amp here in Australia for a reasonable price. What woofer would you recommend for that? I'm open even for 8" if 10" would be too much to handle.

 

[TLS Guy]

Thanks Alex and TLS, good to hear it's totally worth it. I'm now thinking of ditching sealed unit and go for the ported. Now, I can get SPA300 D plate amp here in Australia for a reasonable price. What woofer would you recommend for that? I'm open even for 8" if 10" would be too much to handle.

I do not recommend an eight inch driver for a sub. 10" is marginal, 12" or 15" is better.

What sub drivers are available to you in Australia?

I really need to know what it is you are trying to achieve. It really is important to have a clear idea of what I am designing for. What are you going to use it for, and what is the associated equipment?

 

[Vil]

Ok, this is purely for music. My system is very small and simple. I have a pair of Dali Oberon 3 bookshelfs ran by streaming device Bluesound powernode with 80W per ch. (not sure if this is important info) It has an output for a sub and uses app for enabling it when plugged in. As a side note, it also has HDMI that can potentially be used as a 2.1 system for TV.
I have not checked driver's range here in Aus. but I believe I could get anything available in the world, but things like getting parts from US can get quite pricey at the moment, since our $ is low. I can get this Dayton SPA300D in local seller who also imports drivers. There must be massive range but I'm not expert in this field. Is Japanese stuff any good?

 

[TLS Guy]

Ok, this is purely for music. My system is very small and simple. I have a pair of Dali Oberon 3 bookshelfs ran by streaming device Bluesound powernode with 80W per ch. (not sure if this is important info) It has an output for a sub and uses app for enabling it when plugged in. As a side note, it also has HDMI that can potentially be used as a 2.1 system for TV.
I have not checked driver's range here in Aus. but I believe I could get anything available in the world, but things like getting parts from US can get quite pricey at the moment, since our $ is low. I can get this Dayton SPA300D in local seller who also imports drivers. There must be massive range but I'm not expert in this field. Is Japanese stuff any good?

There is not a massive range. So what drivers does this local seller import? Does he have a website that shows what he has available? If so, please link it. I need to know the details of the streaming device and amp. I suspect it does not have bass management. So now I'm not sure you can even use a sub.

You really should have divulged this information at the start. If members are parsimonious with vital details a huge amount of time is wasted.

This is all very complicated and not simple at all. So, details, details, details!

 

[Alex2507]

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?

Don't get me started.

It's midnight. I'm measuring stuff in my living room thinking about subs after having a real bad time doing brake work on a pick up truck today. All my parts were wrong and the work was hard once I got the parts sorted. But it's done and I'm fed and music is playing.

You provided an alignment a few years ago for dual drivers in an opposed configuration for me. I have yet to build it. You even gave me a smaller round port option in consideration of my limited need for high SPL. The four drivers needed to make two dual driver subs were under $500 at the time at Partsexpress. That alignment/price point/performance level is actually ideal for my application.

I was just about to dig up that thread and check the availability of those drivers. Then sanity returned. I had a quadruple bypass 4 months ago. The brake job today felt like it was gonna kill me. My truck is running for the first time since November but I had to take nitro glycerin for the first time since before the surgery.

I don't quite have the oomph to be building subs ATM.

Still, nothing would make me happier. There's a slick Jett table saw upgrade in the shop I use. I'm thinking about the cabinet now ... now it's 1:00 AM. It's wrong to tempt me like this.

 

[Vil]

Here is Youtube video about Powernode bass management. I’m not sure of its credibility but guy has plugged KC62 sub and explains how it works. It starts at 7:20. I couldn’t explain it the way he does.
This is the importer of drivers:http://wagneronline.com.au/
My room is 3m wide, 5m long and 2.1m tall ( if this is any help)

 

[Vil]

Sorry forgot to include video:

Go to 7:20 about bass management

 

[MrBoat]

Sorry forgot to include video:

Go to 7:20 about bass management

I built a pair of subs based on the Nola Brio Trio 'clone' project over at diyaudio.com. I didn't expect much from it and had moved onto larger subs and speakers and forgot about them until recently. I just bought a Fosi Audio BT30D Pro novelty amp for putting together a small system to take while travelling out of town that could stow in the xtra-cab portion of my Tacoma. The amp has subwoofer accommodations for passive or active subs. As it turns out, the little Peerless sub fills in more than adequately with the system mounted on a table top and the sub firing under the table and actually fills a 4m x 7m room with loud enough music.

It's 254W x 330H x 432D sealed, made of cheap 18mm Radiata pine ply from the local hardware center.

No, it's not active and is probably a train wreck based on the standards of Audioholics but it sounds quite nice for just being powered from the otherwise tiny amp and manages to work well with these tiny speakers for music only. The DIY bookshelf (Speedster) is probably making the sub sound good for all I know but it's working and it doesn't take much for it to work. Basically it is just adding some displacement to the otherwise tiny woofers of the main speakers.

Driver: https://www.parts-express.com/Peerless-830667-8-Paper-Cone-SLS-Subwoofer-264-1102?quantity=1

 

[TLS Guy]

Sorry forgot to include video:

Go to 7:20 about bass management

It really helps to have the proper information.

I have worked on this all morning.

You are right about Australian prices, and I have worked hard to get costs down, but prices are more then double USA.

First of all it was a real challenge to get the spec. of your sub out on the Bluesound unit. It turns out the unit does have fixed bass management. When you activate your have a sub, and connect to the sound out, the main speakers are limited to 80 Hz at the low end, and the sub carries over below 80 Hz. I assume this is 12 db. high pass and 24 db. low pass, but I can't find a spec on that.

The driver is this 10" Dayton sub driver. I use this driver in my in wall system and it is an excellent driver.

I did model the cheaper Dayton 10" driver, but the box volume came out to almost 4 cu.ft. If you go on the sites it says you can use a vented volume of 1.75 cu.ft. That is pure fiction. F3 is much higher then quoted and the response curve is awful.

I have specked two choice of plate amps. This 100 watt amp. I have also specked this 250 watt amp.

If you have the funds I would go for the more powerful amp, as your circumstances may change. The 100 watt amp would probably meet current requirements, but the larger one will power the driver almost to the limit of its capabilities. I am powering my driver with 250 watts.

Now you need to add the volume of the driver, port volume and bracing volume to the final volume. This pretty much turns out to be in the 15 to 20 percent range.

This will make an ideal sub for your system. I'm sorry about the sticker shock, but I can't control Australian prices without designing junk, which I won't do. Junk purchases are the most expensive you ever make.

I feel 100% confident in this design and would expect you to be very happy with it. It should match your system perfectly.

As an aside I think we need an addendum to this site, to state people's country of residence. In addition we need guidelines as to what information to provide when requesting help.

You are far from the first to post with totally inadequate details. This wastes a lot of time.

 

[Vil]

Many thanks TLS, I think I'd rather save and get 250W amp.Yes, it's pricey here but I'd rather have quality gear. Initially I thought it would be much cheaper to build than buying complete unit but this will probably have the quality of subs I would never consider buying anyway so perhaps a save for me. Just have one out of context question. If you keep the volume of the box does a shape of it matter? Would you need to change porting? I believe this is a big deal.
Anyway, I feel very humble and appreciative for what you are doing. For me it's a great learning curve of things I never knew much about and thanks again for your precious time.
I will gather all material and will let you know how I go for sure.

 

[lovinthehd]

FWIW with just one sub there are limited economies of scale, particularly using plate amps (which also complicate box build), but with external multich amps and two or more subs it can be more cost effective.

 

[Vil]

FWIW with just one sub there are limited economies of scale, particularly using plate amps (which also complicate box build), but with external multich amps and two or more subs it can be more cost effective.

Yea, I was also considering getting external amp earlier but not sure if that would bring the cost down. Also, it would probably mean the box to be redesigned and I don't want to waste anyone's time here, it kind of makes me feel bad.

 

[TLS Guy]

Many thanks TLS, I think I'd rather save and get 250W amp.Yes, it's pricey here but I'd rather have quality gear. Initially I thought it would be much cheaper to build than buying complete unit but this will probably have the quality of subs I would never consider buying anyway so perhaps a save for me. Just have one out of context question. If you keep the volume of the box does a shape of it matter? Would you need to change porting? I believe this is a big deal.
Anyway, I feel very humble and appreciative for what you are doing. For me it's a great learning curve of things I never knew much about and thanks again for your precious time.
I will gather all material and will let you know how I go for sure.

Thank you for your kind words. As far as dimensions volume is key. However you don't want the unit excessively tall, as you can get a standing wave. Also making a cube is not good as all reflection points coincide to produce a nasty standing wave. Of course you need a dimension long enough so the port has clearance from the opposite wall. Otherwise have at it.

As far as damping, about 50% of the internal surface should be covered with damping material. Polyfill is often recommended here, but I don't know if you have this in Australia. It is used for stuffing pillows and very cheap.

I have been very pleased with that driver and have it in a transmission line enclosure. I like transmission designs, and it was ideal for going in wall.

This is the performance.

Even though you have a small room, if that unit would fit up against a wall it might work for you I suppose.

I think you are getting the hang of subs now.

 

[TLS Guy]

Yea, I was also considering getting external amp earlier but not sure if that would bring the cost down. Also, it would probably mean the box to be redesigned and I don't want to waste anyone's time here, it kind of makes me feel bad.

No, you could certainly use an external mono amp, if that would bring the cost down. Single channel amps tend to be expensive. You could bridge a bridgeable stereo amp, but I'm not in favor of bridging. In addition as that driver is four ohm you would need a 2 ohm capable amp to bridge it, and I would bet that would make it a more expensive option. You can find what might be available to you. It is difficult advising non US residents.

 

[lovinthehd]

Yea, I was also considering getting external amp earlier but not sure if that would bring the cost down. Also, it would probably mean the box to be redesigned and I don't want to waste anyone's time here, it kind of makes me feel bad.

Just my general preference not to have the amp as part of the sub box, rather have the amp with my other electronics. I use Crown XLS series amps. I don't know what they cost down under, but here they have risen in price here since covid.

 

[TLS Guy]

Yea, I was also considering getting external amp earlier but not sure if that would bring the cost down. Also, it would probably mean the box to be redesigned and I don't want to waste anyone's time here, it kind of makes me feel bad.

It would not mean a box redesign. So if it is cheaper go ahead. With your rig you only have one option for the crossover frequency and that is 80 Hz.

 

[lovinthehd]

That video you posted indicates an app can adjust crossover at other than 80hz.....have you tried that?

 

[Vil]

That video you posted indicates an app can adjust crossover at other than 80hz.....have you tried that?

No, because I believe you need to have sub plugged in, then enable it in the app. Once you have it enabled, you can start playing with crossover frequencies I guess.

 

[lovinthehd]

No, because I believe you need to have sub plugged in, then enable it in the app. Once you have it enabled, you can start playing with crossover frequencies I guess.

I can't imagine how it knows particularly if/what sub is attached. Maybe just stick an rca cable in the port if that's what it detects. I was wondering if he meant a particular matching sub, but it didn't seem so.

 

[Vil]

I might try that but now going away for two weeks. So, will have to leave it for now. Will try ordering some material in the meantime.