Single 12" vs dual 10" subwoofers

[jhaider]

What do you mean? Please explain what you disagree with...

All of your statements above are incorrect, and internally they are inconsistent as well. I don't have time or interest in a piece by piece deconstruction.

 

[Senior NEET Engineer]

All of your statements above are incorrect, and internally they are inconsistent as well. I don't have time or interest in a piece by piece deconstruction.

There is no correct or incorrect. It is my opinion. If you're not interested in debating, then don't comment. Thanks.

 

[jhaider]

There is no correct or incorrect.

That is dangerous intellectual territory.

 

[Peas]

For room correction for the subs, would a Minidsp 2x4 be enough or do I need the 2x4 HD?

For the bass only, the 2x4 boxed will suffice. I have that here, too. You need to open it and adjust the jumper to obtain the higher output.

 

[Peas]

I would not use the unbalanced 2x4. The preout voltage is too low. I have successfully used balanced 2x4. 2x4HD allows longer delays and has standard voltage on the RCA preouts. It is also marginally easier to use if your processor or subs only have RCA inputs. No need to cut cables and make sure they’re wired correctly into the terminal.

The wiring problem doesn't exist with the boxed version of the 2x4 device. As long Koeitje isn't planning a DBA, the delay is far enough.

There's also the Omnitronic SMARD, but I don't have experience with that one.

 

[Koeitje]

For the bass only, the 2x4 boxed will suffice. I have that here, too. You need to open it and adjust the jumper to obtain the higher output.

I see the balanced version has that option, but not the unbalanced one?

The wiring problem doesn't exist with the boxed version of the 2x4 device. As long Koeitje isn't planning a DBA, the delay is far enough.

There's also the Omnitronic SMARD, but I don't have experience with that one.

What does DBA stand for?

 

[Peas]

The unbalanced version surely has. You need to open the box. Took me two minutes or so.

DBA means double bass array, where you have a line or better an array of subwoofers at the front and the same also at the rear side, absorbing the wavefront. The necessary delay is then according to the room length.

But if you place two subs somewhere in-between the front and the listening area, you don't need that.

 

[FrantzM]

For the bass only, the 2x4 boxed will suffice. I have that here, too. You need to open it and adjust the jumper to obtain the higher output.

Inquiring minds would like to know.. Which jumper? Where? How? Pictures?

 

[detlev24]

Inquiring minds would like to know.. Which jumper? Where? How? Pictures?

See miniDSP 2x4 User Manual, pages 38+.

There is also a '2x4 Balanced' version available, besides the '2x4 HD'.

 

[FrantzM]

For the bass only, the 2x4 boxed will suffice. I have that here, too. You need to open it and adjust the jumper to obtain the higher output.

The jumper modifies the maximum input voltage not the output ... From the manual:

The output on the miniSDP 2 x 4 cannot go higher than .9 Volt. As explained by Davey in this DIYAudio post, this is a limitation of the chip used.

 

[FrantzM]

This has become a very interesting debate/thread/ discussion, a request to Koeitje and the community in general ?
Can We hijack you thread and make of it a subwoofer discussion thread? Or should I open one?

 

[Peas]

The output will be lifted by 7 dB as the jumper changes input sensitivity. I wasn't talking about the maximum output but of the output with a given input signal.

And with a standard hifi power amplifier or subwoofer plate amp (as in the SB1000), the output is enough.

With a PA amp, you will need to adjust gain if the device allows.

In sum, try it or leave it. I use the 2x4 in my home theater and it works well on high volumes close to THX reference SPL.

If in doubt, go for the HD. I won't convince you of the opposite, I am just saying tha you could save some budget.

In contrast, I wouldn't use the 2x4 with main speakers due to the noise floor. Then, the HD is highly recommended.

 

[jhaider]

The wiring problem doesn't exist with the boxed version of the 2x4 device.

What? Adding the case does not magically change the Phoenix connectors to XLR.

Also, you are simply mistaken about the unbalanced 2x4. I’ve been there. It required a car audio line driver on a 12V wall wart to be useful. There’s just no headroom for relative gain adjustment and EQ due to the paltry output voltage. Balanced 2x4 is only 20USD more and far more usable, with 4V max output and lower noise floor. You just have to be willing to cut cables. 2x4HD also has double the output voltage of 2x4, but if the delay limits of 2x4 balanced are acceptable I think it is actually their better 4ch subwoofer controller.

 

[Peas]

I'm not sure if I get you right.

Koeitje wants to buy finished subwoofers such as the SVS SB1000 that have a standard line input with RCA connectors. So far so good.

The unbalanced 2x4 boxed has both RCA inputs and outputs. No need for balanced XLR:

https://www.soundimports.eu/de/mini...MIvue0_ofU6QIVg00YCh0ksgu0EAUYASABEgLQAvD_BwE

(As far as I know, the "boxed" in the name always refers to the unbalanced version as this is also available as "unboxed").

If you drive a finished sub by a standard hifi pre-amp or AVR, its volume level is normally set to around 1/3, otherwise you can't match SPL with the mains properly. You will run out of the +/- 12 dB adjustment range most AVRs have.

So if there would be any lack of headroom, it can be compensated by twisting that tiny round plastic knob on the subwoofer's back.

It's getting quite theoretical here, but let me state that it works quite fine in practice.

 

[jhaider]

I'm not sure if I get you right.

It’s about headroom for EQ and level setting.

The unbalanced 2x4 boxed has both RCA inputs and outputs. No need for balanced XLR:

RCA outputs with just 0.9V output. Clip clip! You can wire unbalanced cables to the balanced 2x4 as well. You still get the benefit of much increased headroom. The manual has instructions. I cut up “car audio” Y cables (1m to 2f) with twisted pair construction to put “RCA inputs“ on a 2x4 balanced when I used it. Maybe I’ll dig in my basement later to see if I still have it, for an illustration. But basically you screw the two wires from your unbalanced cable into the block, and add a jumper from cold to ground on one side. If one can turn a screwdriver without losing a finger, one can make use of the superior unit.

(As far as I know, the "boxed" in the name always refers to the unbalanced version as this is also available as "unboxed").

That understanding is incorrect. This is the better miniDSP 2x4 unit for multisub integration, referred to by your sales point as “boxed.” (miniDSP themselves use “in a box”)

https://www.soundimports.eu/de/minidsp-balanced-2x4-boxed.html

It's getting quite theoretical here, but let me state that it works quite fine in practice.

If you don’t apply much EQ or level variation, maybe if you get lucky. Otherwise, clip clip clip! I know that from experience. For movies the difference may not be obvious. In acoustic music with deep bass it is more noticeable.

Either way, the benefits of more headroom for EQ and higher subwoofer input voltage for lower noise far exceed the nominal extra cost and minor hassle of creating adapters for the Phoenix terminals.

 

[Peas]

What I am doing wrong that I never experienced clipping even at high volumes? I have ripole subs that are known for their weak efficiency (SPL at 1 W).

If you apply extensive EQ, the miniDSP will automatically reduce the overall level.

Again, no convincing, just reporting from my experience. Feel free to use whatever surplus-priced product if that gives a better feeling.

 

[HammerSandwich]

Furthermore, the passive radiator must have the same excursion limits as the driven unit, to avoid distortion.

It turns out that a same-area PR needs significantly more excursion, because it operates at lower frequencies.

 

[detlev24]

It all depends on the passive radiator's target (resonance) tuning frequency.

'Salk Sound' has a nicely written comparison of both the design choices - ported vs. passive radiating - on their blog. Yes, the article was written with regards to their "SoundScape" loudspeaker series; but nevertheless provides some good information:

Why Passive Radiators?

[PS: It would be great to have some Salk Sound loudspeakers reviewed on ASR!]

 

[Lonestar1027]

[PS: It would be great to have some Salk Sound loudspeakers reviewed on ASR!]

I have a set of Song3 BeATs on order and I reached out to Amir about potentially testing them. Should have results in the next 4ish months.