In need of a builder...

[BKr0n]

Definitely more compact, and still is able to keep the subs too.

 

[BKr0n]

Ya know... I'm starting to realize something... I'm putting in a lot of effort just to include two 8" woofers. Since it doesn't look like I'll be able to make a force canceling enclosure that's compact, why not just bag the idea and just get a better sub? There's good design, and then there's an extreme amount of effort to do something that is usually reserved for larger enclosures. So I guess I'm off to find a good bass driver. Sub hunting... one ping please... ok I'm done

 

[BKr0n]

So... squeaky clean low end... any recommendations? Seems so far CSS is the go to. Kartesian scores pretty well for flat response as well. Go figure purifi has offerings as well.

 

[voodooless]

why not just bag the idea and just get a better sub?

Well, according to yourself because you wanted a super compact setup with not too many parts to lug around for the foreseeable future

But hey, opinions can change All the more power to better/new insights

The two 4" driver will make for quite a formidable small speaker on their own if you reflex load them. A small sub (or two) would definitely work, but I'm not sure it's worth the money to build your own, though. KEF KF62 is basically the smallest you get, and the technology inside of it cannot be replicated by yourself (at least, currently). Even larger commercial subs are hard to beat, cost-wise, never mind the fit and finish on them.

As for a single enclosure solution: Purifi also make a 8" and 10" woofer. They are around the same price as the dual Seas setup. The 8" one was tested:

Test Bench: The Purifi Audio PTT8.0X04-NAB-02 8” Aluminum Cone Woofer

The PTT8.0X04-NAB-02 is the fifth Purifi woofer to be examined in Test Bench. The new 8" aluminum cone woofer includes the same constant Sd surround, cone edge stiffening ring, and low magnetic hysteresis motor design as previous models. The addition of the unique Purifi NBR surround, make the...

audioxpress.com

Purifi PTT8.0X04-NAB-02 8" Aluminum Cone Woofer

In this blog post I test the Purifi PTT8.0X04-NAB-02 8" Aluminum Cone Woofer and provide some listening impressions. The PTT8.0X04-NAB-02 retails for around $700 USD currently. It sits squarely in the premium 8" woofer category. Purifi sent me a pair of woofers to test and to develop a complete...

josephcrowe.com

Purifi PTT8.0X04-NAB-02 8" Alu midwoofer | HiFiCompass

What is on the test bench? On March 30, 2022, the Danish company PURIFI announced a long-awaited novelty - a long-stroke 8" aluminum cone midwoofer PTT8.0X04-NAB-01. If we draw an analogy with boxing, then this next vertical expansion of their lineup corresponds to the moving from middleweight...

hificompass.com

Looks excellent!

Reflex in 30L, tuned at 30 Hz, this might be nice. You could also use a 10" PR (doesn't have to be a Purifi one) to not have to spend room on a port. Here is closed (blue) vs reflex (green):
MaxSPL

Relative Magnitude:

> 25Hz, > 100dB per speaker should be pretty good. Both of these solution need some EQ to linearize the low end, but you'll need it anyway because your room will mess it up even more.

 

[kemmler3D]

So... squeaky clean low end... any recommendations?

Purifi 10", SEAS 10" or the CSS 10"/12" are the lowest-distortion sub drivers that are good to 20hz that I know of. However, as @voodooless points out, once you start pricing out the drivers, plate amps and so on, it's hard to be cost-effective building your own subs. I was recently looking into this, it's hard to be cost-effective even if you go 2 tiers down from this for the driver and don't get Hypex amps.

Lots of options for subs, I have the KC62s and the extension is great, output is another question but they are champs for the size. Not champs for cost by any means...

 

[BKr0n]

Well, according to yourself because you wanted a super compact setup with not too many parts to lug around for the foreseeable future

But hey, opinions can change All the more power to better/new insights

I guess what I meant to say was LF driver

As for a single enclosure solution: Purifi also make a 8" and 10" woofer. They are around the same price as the dual Seas setup. The 8" one was tested:

I was considering the 8" and then a 10" PR as the port.

Purifi 10", SEAS 10" or the CSS 10"/12" are the lowest-distortion sub drivers that are good to 20hz that I know of. However, as @voodooless points out, once you start pricing out the drivers, plate amps and so on, it's hard to be cost-effective building your own subs. I was recently looking into this, it's hard to be cost-effective even if you go 2 tiers down from this for the driver and don't get Hypex amps.

I mean, I wouldn't say making a good DIY subwoofer is impossible. Dayton does make some decent subwoofers that are reasonably priced and can perform well. But again, looking for an LF driver.

Lots of options for subs, I have the KC62s and the extension is great, output is another question but they are champs for the size. Not champs for cost by any means...

I actually bought the driver for it a while ago, but returned it. I thought I would be able to use it, but there's an inherent part of its functionality that doesn't make it good with a Hypex amp and that is it's extra sense coil. Each driver on the same pole piece has an asymetirc coil. Since there's no guarantee that these coils wouldn't collide in one way or another, they use motional feedback in order to compensate for the mechanical imperfections during cone travel.

 

[a4eaudio]

...However, as @voodooless points out, once you start pricing out the drivers, plate amps and so on, it's hard to be cost-effective building your own subs....

I tend to think of DIY builds vs commercial speakers in three groups:

1. Those where DIY can't compete. These tend to be under $100 where the manufacturer just gets stuff in such large quantities that DIYers just can't get things that cheap. Or $100K speakers where I just can't match the exquisite cabinet but may be able to match the sound quality.
2. Those where I can build something DIY that is as good or better than a commercial speaker costing 4 to 10 times more. This is a typical two or three way speaker without anything too fancy.
3. Those were I can build something DIY that costs about as much as a commercial speaker but outperforms the commercial speaker by a decent amount.

I would put a good subwoofer in category 3.

• A CSS SDX12 driver and a 500 watt plate amp with DSP is going to cost a little less than an SVS SB-200. Add in cabinet costs and its probably getting closer. But I bet the CSS destroys that SVS.
• I have two CSS SDX12 drivers that I won't get to using until next year. I will likely power them with something like a Crown 2x1200 watt DSP amp. This will be about 15-20% less (just drivers and amp) than two SVS SB-2000s. This should clearly outperform the commercial speakers. (I actually got the CSS drivers for half off, so I will be in for much less than commercial subs.)

The Dayton Audio Reference 12-inch or Ultimax II 12-inch are a little less than half the price of the CSS driver and I wouldn't be surprised if they outperform the SVS subs.

 

[BKr0n]

Ok so a quick and dirty for LF drivers. Each curve is tuned for 20L with a 200Hz lowpass. The CSS 10" kind of took me by surprise, but the ported curve looks a little weird. Two things to note:
1) Chose the Ultimax II 10" over the 12" just for the smoother transition (see the spec sheets for the 10" and the 12")
2) Purifi 10" isn't in the running, but I thought I would put it there since there's a lot of 10" and 12" options and it would be a closer "apples to apples" comparison

 

[BKr0n]

But I bet the CSS destroys that SVS.

Sounds like a fan to me

I will likely power them with something like a Crown 2x1200 watt DSP amp.

Hey look a brand that's not Hypex! I would imagine there are other brands out there, but Hypex seems to be the defacto. Someone introduced me to Four Audio as well and I know miniDSP has theirs, but those are the only plate DSP amps I can think of in terms of high performance.

 

[a4eaudio]

If you are modelling the CSS drivers with a port, make sure you check out the port velocity and port length that will be required. (Hint, it will be ridiculously long.) You pretty much have to go with passive radiators or sealed. I have the PRs but have pretty much decided I won't use them and will go sealed with DSP.

Hypex is good stuff but also usually on the pricey side. Probably worth it, I just usually tend toward more thrifty options. I haven't looked lately, but will have to look at the options. The Crown is a good bang-for-the-buck solution.

 

[BKr0n]

If you are modelling the CSS drivers with a port, make sure you check out the port velocity and port length that will be required. (Hint, it will be ridiculously long.) You pretty much have to go with passive radiators or sealed. I have the PRs but have pretty much decided I won't use them and will go sealed with DSP.

The CSS looks great so I can see the appeal. A question then is can PRs work correctly if the driver isn't centered on the baffle?

 

[BKr0n]

It has been brought to my attention that, if I can avoid it, and am going to use an LF driver anyway, go with sealed... So I'm going with sealed lol

 

[voodooless]

A question then is can PRs work correctly if the driver isn't centered on the baffle?

Sure, why not? It doesn't matter where the woofer and PR are located, as long as they are in the same air compartment.

 

[BKr0n]

https://sbacoustics.com/product/10in-sw26dbac76-4/ hmm... this may be a better alternative...

 

[BKr0n]

I think this solves the Vas problem. The woofers have a thin enough profile to allow for greater volume within the enclosure. It's super simple, and it could probably be made a multitudinous amount of ways. Personally, I'm a fan. I could add a little bracing, but other than that I think it's ready.

 

[BKr0n]

@voodooless Playing devils advocate I decided to try and see if I could fit that push-pull wave guide with the two drivers and, yeah, it would fit, but I would have no idea how much room I would have left if I did that. I also had to mess with the size of the waveguide so not sure how that would work out either.

 

[nc535]

I think the dual opposed side woofers are your best option but two sealed 8's leaves you a little short in the bass department, depending on how loud you want to play. It looks like you could fit Dayton LS10 low profile woofers, 10" dia, 10 mm Xmax for about 75% more volume displacement.

 

[BKr0n]

I think the dual opposed side woofers are your best option but two sealed 8's leaves you a little short in the bass department, depending on how loud you want to play. It looks like you could fit Dayton LS10 low profile woofers, 10" dia, 10 mm Xmax for about 75% more volume displacement.

Was also considering this one https://sbacoustics.com/product/10in-sw26dbac76-4/ can reach a little lower and has a bit of a thinner profile (3.3" over the dayton's 3.8"). Also a little flatter overall (although not by much).

 

[voodooless]

You may want to watch this thread:

https://www.audiosciencereview.com/...for-sub-bass-in-shallow-sealed-cabinets.57015

 

[BKr0n]

You may want to watch this thread:

https://www.audiosciencereview.com/...for-sub-bass-in-shallow-sealed-cabinets.57015

Man I wish I could fit two of the 10" CSS woofers. Fairly certain they're too big, but they haven't released a full spec sheet so not completely sure. Would be neat though