Topic: Connecting a subwoofer

Hi,

I am keen to connect an active sub-woofer into my system but I am struggling to understand how to best do this.

I currently have my ADI-2 Pro FS R BE connected to my Sugden Masterclass AA power amp via balanced connections. My speakers are simply connected to the Sugden’s speaker outputs.

How is this normally done? Perhaps I have to take a separate unbalanced cable pair from the RME direct to the sub’s power amp? Any insights would be welcome!

Thanks,

David.

RPi4 | RME ADI-2 Pro FS R BE | Senn HD600 | Sugden Masterclass AA | Teddy Pardo i80d | Naim SBL

2 (edited by ramses 2021-07-10 15:27:17)

Re: Connecting a subwoofer

What subwoofer ? Subwoofers are different, some have a terminal to connect the satellite speakers so that frequency ranges are properly separated between the subwoofer and the satellite speaker.

I personally would only invest into a subwoofer which has such a connection for satellite speakers.

Then you would connect the subwoofer to the ADI-2 Pro and the satellite speakers to the subwoofer.

Depending on the model of subwoofer there might be switches to fine-tune crossover frequency etc.

BR
Ramses
X10SRi-F, E5-1650v4, Win10Pro21H2, Cub10Pro, UFX+, XTC, 12Mic, ADI-2 Pro FS R BE, RayDAT

Re: Connecting a subwoofer

Hi,

Thanks for your reply. The model which I am considering is SVS PB 3000 - it seems to have RCA L/R both in and out. I guess from what you are saying, that would mean I replace the Sugden as PA with the PA in the SVS?

If so, that does not sound like what im trying to achieve as would like to keep the Sugden for the regular speakers.

Is there some other model of sub which is a closer to what im trying to achieve?

Thanks,

David.

RPi4 | RME ADI-2 Pro FS R BE | Senn HD600 | Sugden Masterclass AA | Teddy Pardo i80d | Naim SBL

Re: Connecting a subwoofer

David,

Fine Selection on your behalf for choosing an SVS Sub!   They (SVS) are an excellent group of really talented people to work with, and their Customer Guidance/Support is above comparison.  I say this as a Long Time, and very satisfied SVS Owner

To that end, let me direct you to the Top Engineer at SVS who is best qualified to guide you:

Ed Mullen
edm@svsound.com

Enjoy!!

Best Regards,

Curt

Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes

Re: Connecting a subwoofer

Thanks Curt and Rameses, I will contact SVS directly on how best to do this. I am a beginner in the area of connecting subs!

RPi4 | RME ADI-2 Pro FS R BE | Senn HD600 | Sugden Masterclass AA | Teddy Pardo i80d | Naim SBL

Re: Connecting a subwoofer

David,

You're in Fine Hands with SVS. There's a good chance Ed designed your Sub.  Whose opinion would you prefer?  His or that of a committee?  wink

Wishing you a successful outcome.

Curt

Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes

7 (edited by KaiS 2021-07-11 01:28:26)

Re: Connecting a subwoofer

davidr99 wrote:

I am a beginner in the area of connecting subs!

You can find the SVS PB 3000 user manual here:
https://cdn.shopify.com/s/files/1/0921/ … pdf?669376

It answers a lot of possible questions.


The downside of the SVS PB 3000 is, it does not contain a High Pass Filter for the main speakers - they have to run full range.
Depending on the type and size of the mains and your listening loudness demands this can be a problem or not.


I have developed a convenient way to integrate a sub into an existing setup using ADI-2’s EQ as filter.
If you’re interested, let me know.

Re: Connecting a subwoofer

KaiS wrote:

I have developed a convenient way to integrate a sub into an existing setup using ADI-2’s EQ as filter.
If you’re interested, let me know.

I'm interested.

Re: Connecting a subwoofer

Could you kindly drop me a copy as well, surely interesting Kai, many thanks upfront.

BR
Ramses
X10SRi-F, E5-1650v4, Win10Pro21H2, Cub10Pro, UFX+, XTC, 12Mic, ADI-2 Pro FS R BE, RayDAT

10 (edited by KaiS 2021-07-12 18:09:34)

Re: Connecting a subwoofer

A typical main speakers + subwoofer configuration would either use:

• A dedicated crossover frequency splitting that sends the bass to the sub and the remain to the main speakers - with the disadvantage that the filter artifacts spoil the sound quality.

• Or no filtering for the main speakers at all, just adding the sub on top.
The main speakers would still need to deliver the full bass energy, trying to produce frequencies that they are not capable of.
This minimizes the possible advantage a sub can give in extension and clarity.


The basic idea for a solution is simple:

• Connect both mains AND sub to the same stereo output, e.g. by using both the XLR and RCA out.

• To reduce the load on the main speakers/amp, use ADI-2’s EQ’s shelving filter to bring down the low frequencies.

• Now fill the missing bass with the sub.


This way only one stereo output is needed, opposed to when a real 2-way crossover is emulated, which would only be possible with ADI-2 Pro’s dual outputs anyway, and is quite uncomfortable in multiple ways.


The other advantages:
• The main speakers still partly contribute to the bass, improving the bass quality and give a smooth transition to the sub.
• The still multiple sources for the bass (instead of a single sub) give a better room coupling, reducing unwanted room resonances / modes.
• A soft shelving filter does not, like a high/low pass filter of a normal x-over with steep cuts, introduce a bad impuls- and phase response.

And, even a moderate bass reduction of only 6 dB reduces main speakers driver excursion and power amp load to 1/4, this can be a night and day difference in clarity.


Here is a setup guide.
It reads a bit lengthy, but in fact is straight forward, go for “case1”:
https://forum.rme-audio.de/viewtopic.ph … 12#p155312

The guide even explains the use of an easy to obtain and inexpensive measurement tool, which by itself improves the sound quality by a significant margin.

Re: Connecting a subwoofer

To update everyone, I received email from Ed at SVS, as suggested by Curt. His recommendation in my case was to keep my balanced connection to the Sugden PA, and existing passive speakers as they are, but use the RME’s unbalanced output to connect to the sub using RCA. He also supplied helpful suggestions on how to set the slope for sealed/vented speakers.

Full marks to Ed and thanks to Curt for the contact.

Regards,

David.

RPi4 | RME ADI-2 Pro FS R BE | Senn HD600 | Sugden Masterclass AA | Teddy Pardo i80d | Naim SBL

Re: Connecting a subwoofer

davidr99 wrote:

To update everyone, I received email from Ed at SVS, as suggested by Curt. His recommendation in my case was to keep my balanced connection to the Sugden PA, and existing passive speakers as they are, but use the RME’s unbalanced output to connect to the sub using RCA. He also supplied helpful suggestions on how to set the slope for sealed/vented speakers.

Once you got the sub I suggest you read my posting above again.
I added some explanations.

The method described comes from practical evaluation, e.g. is used for my recording studio’s nearfield monitoring, where it produces an even soundfield for a larger listening area.

Re: Connecting a subwoofer

KaiS wrote:

• Connect both mains AND sub to the same stereo output, e.g. by using both the XLR and RCA out.

• To reduce the load on the main speakers/amp, use ADI-2’s EQ’s shelving filter to bring down the low frequencies.

• Now fill the missing bass with the sub.

I don't get it.

If you are connecting both the mains and the sub to the stereo "line out" output, the output of the RCA and XLR outputs are the same, just 6dB different, and you are cutting the low frequencies out with the EQ, how is the sub supposed to fill in the missing bass when it's been left out by the EQ?

I am doing the same as davidr99 and it sounds pretty good to me once the sub volume and crossover point on the sub are set up right.

14 (edited by KaiS 2021-07-13 17:18:55)

Re: Connecting a subwoofer

mediummanting wrote:
KaiS wrote:

• Connect both mains AND sub to the same stereo output, e.g. by using both the XLR and RCA out.

• To reduce the load on the main speakers/amp, use ADI-2’s EQ’s shelving filter to bring down the low frequencies.

• Now fill the missing bass with the sub.

I don't get it.

If you are connecting both the mains and the sub to the stereo "line out" output, the output of the RCA and XLR outputs are the same, just 6dB different, and you are cutting the low frequencies out with the EQ, how is the sub supposed to fill in the missing bass when it's been left out by the EQ?

I am doing the same as davidr99 and it sounds pretty good to me once the sub volume and crossover point on the sub are set up right.

My suggestion is, NOT to cut out the bass with a High Pass Filter, but only reduce bass by 6 to 10 dB with a Shelving Filter.

See the difference?

Re: Connecting a subwoofer

KaiS wrote:

My suggestion is, NOT to cut out the bass with a High Pass Filter, but only reduce bass by 6 to 10 dB with a Shelving Filter.

See the difference?

And whack up the volume on the sub to compensate?

16 (edited by KaiS 2021-07-14 09:31:31)

Re: Connecting a subwoofer

mediummanting wrote:
KaiS wrote:

My suggestion is, NOT to cut out the bass with a High Pass Filter, but only reduce bass by 6 to 10 dB with a Shelving Filter.

See the difference?

And whack up the volume on the sub to compensate?

Exactly.
This way the sub takes over the majority of work with the bass.

The main speakers run cleaner now when their membranes have a largely reduced excursion.
For me it‘s the superior way for sub integration, getting the “best of both worlds“ from  - real x-over vs. no x-over at all.

The best way to setup a sub in general is in the link:
https://forum.rme-audio.de/viewtopic.ph … 12#p155312

Could be done by ear and estimation too, but the guide optimizes the setup.

Re: Connecting a subwoofer

KaiS wrote:
mediummanting wrote:

And whack up the volume on the sub to compensate?

Exactly.
This way the sub takes over the majority of work with the bass.

The main speakers run cleaner now when their membranes have a largely reduced excursion.
For me it‘s the superior way for sub integration, getting the “best of both worlds“ from  - real x-over vs. no x-over at all.

Problem is that my subwoofer is set to almost full volume as it is (the volume knob is past three o'clock) so I can't really attenuate the low frequencies.

It doesn't sound bass heavy, I've just found that a high volume and low crossover setting sounds the best with my speakers and room.

18 (edited by KaiS 2021-07-15 12:18:13)

Re: Connecting a subwoofer

mediummanting wrote:
KaiS wrote:
mediummanting wrote:

And whack up the volume on the sub to compensate?

Exactly.
This way the sub takes over the majority of work with the bass.

The main speakers run cleaner now when their membranes have a largely reduced excursion.
For me it‘s the superior way for sub integration, getting the “best of both worlds“ from  - real x-over vs. no x-over at all.

Problem is that my subwoofer is set to almost full volume as it is (the volume knob is past three o'clock) so I can't really attenuate the low frequencies.

It doesn't sound bass heavy, I've just found that a high volume and low crossover setting sounds the best with my speakers and room.

• You could try to reverse connections:
XLR is 6 dB hotter than RCA.

• If your mains speaker amp has input level controls, you could bring them down.
This would improve ADI-2’s dynamic range BTW, but that’s another story.

• If your external amp does not have a volume control, use variable passive attenuators to fit the level:
https://forum.rme-audio.de/viewtopic.ph … 42#p120442


If you change something, remember the current state, so you can come back if you don’t like the result.
A pencil can mark controls positions e.g.

Re: Connecting a subwoofer

KaiS wrote:

• You could try to reverse connections:
XLR is 6 dB hotter than RCA.

• If your mains speaker amp has input level controls, you could bring them down.
This would improve ADI-2’s dynamic range BTW, but that’s another story.

• If your external amp does not have a volume control, use variable passive attenuators to fit the level

I run the RME straight into power amps and I'm unwilling to swap balanced and unbalanced outputs, so an attenuator would be the only option.

Irritatingly I sold some inline XLR attenuators a few months ago!

Re: Connecting a subwoofer

How is a subwoofer connected to an Adi2 FS?

21 (edited by KaiS 2021-09-12 00:56:02)

Re: Connecting a subwoofer

phrangko wrote:

How is a subwoofer connected to an Adi2 FS?

You mean the one without LCD display, without DSP?

Same like above, paralleled to the main speakers, but setup is different:
You have to work with the Sub’s controls and speaker placement to achieve satisfactory results.

Use Audiotools FFT or RTA to get assistance from measurements to optimize settings:

https://apps.apple.com/de/app/audiotools/id325307477
You don’t need any in-app purchases, the basic toolset contains all that is necessary.