Bass Management

[Ron Texas]

Most users have a 2 channel USB dac or the like for computer audio and don't have the additional hardware to do more than 2 channels, the basic minidsp give then four to work with. We are saying the same thing.

Which MiniDSP are you using, and are you using it as a DAC for your mains? The Crown just sets up a high pass filter. The frequency is variable, but it is a 24 db per octave fixed. Low pass is implemented in the plate amp on the ML Dynamo 1000W sub. The knob is not calibrated except at the extremes, and there is no published spec for it's slope. I would say there is a fair amount of bleed through.

 

[Worth Davis]

I don’t use it as a dac or digital volume knob. Dirac 22a model. As long as they are the same type and slope it should be ok

 

[Ron Texas]

After reading many reviews on Amazon of the LS50W, I am cooling my jets on that one. Too many complaints of the right speaker failing or the finish not being up to the level of the passive LS50. I am investigating the Minidsp 2x4HD to use either as a sub woofer controller or as a DAC/EQ/sub woofer controller. Yes, I know it measures mediocre as a DAC. Zeos went head over heels in his review of the 2x4HD. OK, he is a bit nuts and with his apartment looking like the insides of a 1960's TV he probably hasn't been laid in a year.

 

[LTig]

5. I wonder about the viability of not rolling off the mains at all. I don't believe this is a good alternative with speakers like the LS50 which I have now, or nearly all 2 way bookshelf speakers. However, with tower speakers having significantly better power handling I wonder if this would get good or great results. There aren't any tower speakers I am in love with right now, either.

It's not a good idea, especially with smaller mains. Even my (ok, small) 3-ways profit a lot of not having to handle deep bass. The O300D starts to sound boxy when it must deliver higher levels of deep bass. The integration of a Genelec 7060B (which handles the bass management) brought not only deeper bass but also much cleaner and dryer bass. This is one of the reasons why I don't plan to replace the O300D by the newer KH310. The biggest improvement of the KH310 is 7 dB higher bass level which is not needed when a subwoofer handles the bass.

One of the advantages of 2.1 systems is that you can place the speakers such that the cancellation of the lowest mode of the sats (away from wall) is below the crossover frequency, and that of the subwoofer (close to wall) above; hence no cancellation of the lowest mode for all speakers. Without a crossover of the mains this would not work.

6. Some of the active speakers have bass management built in. The LS50W even has a sub out connection. For $2200 I consider it a possibility. My LS50's could be sold or given to a relative. If I wanted an upgrade this probably makes more sense than buying an SHD plus a Hypex amp.

If a subwoofer (like the above mentioned Genelec) has its own bass management you can feed it the stereo line signal and connect the power amp feeding the mains to the satellite outputs.

 

[MetalheadRich]

After reading many reviews on Amazon of the LS50W, I am cooling my jets on that one. Too many complaints of the right speaker failing or the finish not being up to the level of the passive LS50. I am investigating the Minidsp 2x4HD to use either as a sub woofer controller or as a DAC/EQ/sub woofer controller. Yes, I know it measures mediocre as a DAC. Zeos went head over heels in his review of the 2x4HD. OK, he is a bit nuts and with his apartment looking like the insides of a 1960's TV he probably hasn't been laid in a year.

"a year", boy are you a glass half-full kinda guy or what?

 

[D700]

I have LS50's on the KEF Premier stands filled with lead shot, decoupled from concrete floor with the little metal coaster things. 2' out from wall, fed by HD-AMP1 (modest 50 watts).

I listened initially without sub, had plenty of bass. I redid an office and had a small MicroVee sub I wasn't using, decided to pair that with the LS50s...now too much bass. Years ago I built some high pass filter boxes for speaker cables, starts steep roll off at 100hz, so I added those, now there wasn't enough bass. When I turned up the sub, it just didn't sound right, too muddy. This was a bigger room, so what worked in small office wasn't right for big room.

Then I came across this article from KEF:
https://www.kefdirect.com/blog/tips-for-integrating-your-subwoofer-and-speakers

Particularly this passage:

Set the Volume Properly
We all love massive amounts of bass. But too much bass is, well, too much! Play a song or a bit from a movie you are familiar with (and that has lots of bass) with the subwoofer gain set all the way down (infinity). Slowly adjust the subwoofer gain to the point where you can hear the bass begin to fill in the bottom end. THEN STOP! That’s it, that’s all the bass you need. It may not be all the bass you want but that’s a personal choice. Keep in mind, when a song or soundtrack to a film is mastered the engineers and directors put in the amount of bass they feel is necessary – in relation to all of the other frequencies – to convey the message or emotion of the passage. If you’ve set the subwoofer volume properly it will be loud and subtle as designed and it will integrate with the entire program or passage as intended.

.....The -3dB frequency is the frequency you want to use when setting your subwoofer crossover – in the case of the LS50 that would be 79Hz.

I removed the high pass filters, set the sub for 1 tick below 80hz, followed these instructions and viola, perfection. Haven't touched it since.

Good luck!

 

[DonH56]

The rule used to be "if you can hear the sub, it's too loud". The idea was essentially the same as KEF's statement -- turn up the sub until you hear it as a separate thing, then back off just a hair. It should fill in the bottom octave or three in the overall context of the music, not call attention to itself. These days we see HT guys adding massive amounts of bass boost to "pressurize the room" and "really feel the bass". It is unrealistic, but they like it. Nor am I immune, as I run a few dB boost in my own system sloping from about 100 Hz on down. Part of the problem for me, and perhaps others, is that mix levels seem to run around 80 dB or even higher (as told to me by a couple of film engineers and at least one audio guy), whereas I tend to listen at more like 65~70 dB, and so the mix sounds bass-shy to me (Fletcher-Munson curves and all that jazz).

But I imagine most of us have a friend who applies 10+ dB of bass boost and wants more.

 

[617]

This is more or less what I am thinking. 2 way stand mounts benefit a lot from being rolled off because of their limited power handling. There is also a reduction in distortion.

Stuffing the port of the LS50 will improve power handling and roll off the bass at 6db/octave, which will generally make subwoofer integration easier.

 

[Ultrasonic]

After reading many reviews on Amazon of the LS50W, I am cooling my jets on that one. Too many complaints of the right speaker failing or the finish not being up to the level of the passive LS50. I am investigating the Minidsp 2x4HD to use either as a sub woofer controller or as a DAC/EQ/sub woofer controller. Yes, I know it measures mediocre as a DAC. Zeos went head over heels in his review of the 2x4HD. OK, he is a bit nuts and with his apartment looking like the insides of a 1960's TV he probably hasn't been laid in a year.

Have you made a decision now? For info. I have a miniDSP 2x4 HD that I'm using as crossover to my mains and to EQ the sub. It's still a work in progress in terms of optimising the crossover but I'll happily try to answer any questions if you have them.

My main speakers go low enough to excite a significant room mode at 37 Hz. Without a HP filter applied to the mains this would still be present no matter how flat I could EQ the sub (or even engineer a dip at this frequency). For Blu-Ray playback I use the 2.1 analogue outputs of my blu-ray player which applies its own 80 Hz crossover. It's such a slow roll-off though that even with this the 37 Hz peak from the mains is still obvious on measurements. My sub's own inbuilt LP filter also has a very slow roll-off. The 2x4 HD allows much steeper crossovers to be applied (up to 48 dB / octave) which I think will generally be rather better, and in my own case means I can prevent any issue at my 37 Hz room mode.

Edit: I will just add that the only times I've heard the Kef LS50 wireless speakers they sounded very impressive (at a show).

 

[daftcombo]

But I imagine most of us have a friend who applies 10+ dB of bass boost and wants more.

So true... Such a boost makes all EDM sound good, it's a cheat!
But a bass boost should depend on the SPL, which varies, so several setups (one for the day, one for the night, etc.) is a good idea.

 

[Ron Texas]

@Ultrasonic the only thing I have done so far is get a UMIK-1 and equalize the sub. It makes up a lot for the wonky crossover in the SUB.

 

[TimW]

I am in a similar predicament as I have a 2.2 multimedia system I'm trying to get dialed in. I was using an older Marantz Pre/Pro for input switching, volume control, and crossovers but I had to use a minidsp 2x4 (non HD) for equalizing my two subs. I used the minidsp because the old Audyssey system produced poor results and the two subwoofer outputs were merely duplicates and did not equalize the subs independently. The Marantz only has HDMI 1.4 with no 4K support and due to an odd incompatibility with my Roku I could not connect them together directly. So I have decided to go with completely separate components with high enough performance and all the features I need without a whole lot of others that I don't.

My amp is the Yamaha P3500S which I picked up in new open box condition for $250. I purchased it because it supposedly measures well, is fairly efficient, has plenty of power and was a reasonable price.

For HDMI input I have decided to go with the ViewHD VHD-UHD4X1A switch. It has HDMI 2.0, HDCP 2.2, and can go up to 4K@60Hz with support for HDR. I chose this particular model because it gives me 4 inputs, remote control function (compatible with Logitech harmony), choice of audio EDID selection, and optical output. I select the 2CH EDID and use the optical output to feed my DAC.

Right now I'm using a Pro-Ject Pre Box S2 Digital as DAC and volume control. It is powered by my music server via usb which is also how I stream music when I do serious listening. It measures fairly well and the remote volume control is needed, but I stole it from another system and don't plan on using it indefinitely. Mostly because I still have to use the minidsp 2x4 after it to get crossovers and equalization.

From the beginning my plan has been to replace the Pro-Ject and 2x4 with a minidsp DDRC-24 (2x4 HD with Dirac) but now I'm starting to question the idea. The DDRC-24 is almost perfect because it has optical input, usb input, remote volume control, 4 outputs with high and low pass filters, and what is supposed to be an excellent automated room correction system. Also I already own a Umik-1. The only issues with it are that it only has single ended outputs, which is probably not a big deal, and mediocre DAC performance which is maybe a big deal? As @Ron Texas as said, it would be a waste to use the 2x4 HD with a low distortion amplifier. And I would like to feed my Yamaha a low distortion balanced signal. On the other hand I feel that the advantages of DSP outweigh the disadvantage of a 90dB SINAD which isn't all that bad. This system certainly isn't worth the cost of a minidsp SHD and I don't want to spend that much. Is there any other products out there that can do these things? Have you bought anything new Ron?

 

[Ron Texas]

@TimW I haven't bought anything (audio-wise) since getting the Umic-1. Taming the sub made a big difference. Today moved the speakers closer to the wall and now there is an adjustment at 90hz, just outside of the sub range. Is it really necessary to equalize the subs separately?

 

[TimW]

Is it really necessary to equalize the subs separately?

My subs are in different locations and measure very differently. I figured this meant I should equalize them separately from each other.

 

[g29]

@Ron Texas, what are your input sources ?

Have you ruled out an external crossover to control the main/sub integration ?

If you are using a PC only, JRMC has software crossover filters (6dB to 48dB/octave) so something like the new OKTO Research DAC8 PRO would allow you to integrate your mains with one or two subs. PC(software XOs) -> OKTO Research DAC8 PRO -> amps -> speakers & sub(s). I don't think the JRMC software XO filters will work with DSD content though.

If you have more sources, an external XO maybe an option.

 

[Olli]

@Ron Texas,

Subs are just great, even combined with large floorstanders. A no brainer with small bookshelfs IMO.

My first sub set up was with a cheap & small sub from a German company called Nubert (https://www.areadvd.de/hardware/2010/nubert_nujubilee_AW35.shtml) with a build in XO and 2 active near field monitors. Sounded dreadful! Things got much better dialing the sub in following Barry's approach on http://www.soundoctor.com/. No DSP involved so far, but better placing and phase + gain matching helps a lot.

Then I upgraded to 2 subs. Adding a 2nd sub is worth a lot, as you can see from Alan's measurements here: https://www.audiosciencereview.com/...er-selection-criteria.7080/page-6#post-164013

Next I bought a MiniDSP DDRC22D with Dirac on board. XO was still done inside the subs, but with DIRAC the improvement was great. It still helps to do proper sub placement, but EQ'ing them is far more efficient. Ideally you first place them acourately and then run the EQ.

I then came across @mitchco 's general article on Audiolense (https://audiophilestyle.com/ca/ca-a...nd-room-correction-software-walkthrough-r682/) and his follow up on sub integration using the same software (https://audiophilestyle.com/ca/ca-academy/ integrating-subwoofers-with-stereo-mains-using-audiolense-r712/ ) - it may sound a bit complex in the beginning, but it really is easy in the end if you follow Mitch's article step by step and totally worth the hassle. Of course it only makes sense if you listen to music from a computer.

My experience with other stuff you mentioned:

Ad 4) MiniDSP SHD
I also have a MiniDSP SHD. I can switch between this (2CH) set up with 2 subs and the Audiolense set up described above. I like the Audiolense set up better, I've also taken measurements in REW to confirm that there are differences: https://www.audiosciencereview.com/...in-roons-convolution-engine.7271/#post-167072

Ad5) Rolling Off Mains:
As you said - for your LS50, I would definitely roll them off somewhere between 60 and 100 Hz depending on you room and the subs you want to use. But I also roll off my large floorstanders at 68 Hz although they have a good response down to 30 Hz. Here's a good explanation why rolling of might make sense if you decide to not use Audiolense: http://www.soundoctor.com/whitepapers/subs.htm
Another factor is that you put much less stress on your amp if you limit its bass load; plus, if you buy a good sub, even with good quality mains - they will sound more accourate deep down.

So coming back to your set up and willing to spend about 2.2 K to upgrade your sound I would try the following:

1) Keep your LS 50's. Haven't heard them, but the powered version LS50 Wireless which sounded impressive. If you don't like your current amp anymore, why not buy an entry level Hypex amp, e.g. the March Audio P252, which is around 700 USD I believe.

2) Buy a 2nd sub. Ideally you have 2 subs that are the same, but in my office I am still using the little Nubert sub, plus a JL Audio E112 which is much bigger - adding the little Nubert was still way better than just using the far better JL Audio sub alone. http://www.rythmikaudio.com/products.html has great subs, entry level subs are quite affordable. The entry Level sub L12 e.g. is 539 USD shipped.

3) Buy a MCH DAC. The cheapest option is indeed the Mini DSP 2x4 at 95 USD, or the HD version for 205 USD. Or the UDAC-8 at 255 USD. I have a Motu Ultralite MK4 if you want better DAC chips - you can get one around 500 USD. If you need volume control, the Okto Research DAC8 Pro is really cool.

4) Get Audiolense XO, another 500 USD.

Happy to help if you come across any problems!

 

[Ron Texas]

@Ron Texas, what are your input sources ?

Have you ruled out an external crossover to control the main/sub integration ?

If you are using a PC only, JRMC has software crossover filters (6dB to 48dB/octave) so something like the new OKTO Research DAC8 PRO would allow you to integrate your mains with one or two subs. PC(software XOs) -> OKTO Research DAC8 PRO -> amps -> speakers & sub(s). I don't think the JRMC software XO filters will work with DSD content though.

If you have more sources, an external XO maybe an option.

Just one source, an Intel NUC. Now that I have it working right, don't feel motivated to do anything.

 

[g29]

Just one source, an Intel NUC. Now that I have it working right, don't feel motivated to do anything.

Great, then you have some very short signal chain options available to you with components that all measure very well. Good luck on your decisions and keep us posted as to what you end up with.

 

[edechamps]

Is it really necessary to equalize the subs separately?

When using multiple subs, adjusting their response separately makes it possible to equalize for seat-to-seat variations (a.k.a "spatial equalization", a.k.a "sound field management (SFM)"). This can be quite effective at solving problems with room modes. Multi-Sub Optimizer is an example of software that can do this kind of optimization for you.

 

[mitchco]

Is it really necessary to equalize the subs separately?

Others have made good points - SFM and MSO are very good. Also see post: https://www.audiosciencereview.com/forum/index.php?threads/measuring-time-delay.7644/#post-179442