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Subs & Satellites - can it be done right?

Trell

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For best results the satellites need to play flat one octave below the crossover so 40Hz to 50 Hz.... many small satellite can't do this which makes integration with subs difficult.

The crossover used for Genelec SAM monitors and subwoofers is an Eighth-order Linkwitz–Riley crossover (LR8, LR-8) with slope 48dB/octave, pretty steep. No need for the monitors to play flat one octave below crossover.
 

levimax

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I have to agree with Sigberg regarding not needing a full octave below the crossover frequency. If you are doing a 24 dB/octave crossover, and the signal is obviously -6 dB at the crossover point, then an octave lower it is ~30 dB lower (I know log scale math doesn't exactly work this way). An octave below crossover the attenuation of the sub is less than -0.1 dB. It doesn't matter if you add in a -30 dB signal or a -100 dB signal to the -0.1 dB, you end up with a flat signal. In fact, a brickwall cutoff a half octave below crossover still results is <0.1 dB attenuation. A bookshelf that is flat to mid-to-low 60 Hz range is fine to cross at 80 Hz.

The biggest problem with crossing small monitors is not where they roll off, it is the level they can drive before they get crazy distortion. A lot of 5.25 inch monitors have 5%+ THD at >100 Hz near loud-ish but possible listening levels - and those speakers would be really hard to cross over.
OK I stand corrected. For crossovers I work on between woofer and mid it always seems to work better if there is at least close to an octave overlap in the driver responses but subs are different I guess.
 
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MikeFromNorway
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Guys, interesting discussion but we are FAR off topic here. Please read my first post.
 

dshreter

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KH 420 reaches 26 Hz. Are you sure you would even need subwoofers at all? For most home applications, I'd expect KH 310 and subwoofers to be more than adequate even for an endgame system if you prefer satellite + subs unless you have truly exceptional SPL requirements.

If you're serious about perfect integration, I'd continue the discussion focusing on room treatment rather than electronics as that is the crux of the problem while the electronics are the details.
 

levimax

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KH 420 reaches 26 Hz. Are you sure you would even need subwoofers at all? For most home applications, I'd expect KH 310 and subwoofers to be more than adequate even for an endgame system if you prefer satellite + subs unless you have truly exceptional SPL requirements.

If you're serious about perfect integration, I'd continue the discussion focusing on room treatment rather than electronics as that is the crux of the problem while the electronics are the details.
Multiple subs placed on the sides of the room can fill bass room modes in a way that full range speakers in their proper position can't. Full range speakers with multiple subs and room treatment would be the ultimate.... if you can afford it, have the room, and have a very understanding partner.
 

Worth Davis

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Hi guys.
Actively looking for my end-game setup. There is so much great info in here. I need some advice.
There are pro's and con's for setting up a system with 2 satellite speakers and 2 or more subs. The pros as I understand among others are:

-better room integration
-smoother bass response
-cheaper then fullrange speaker with same specs

Cons
-hard to integrate properly
-WAF? too many boxes
-others?

I have been looking at the Neumann 420 pluss 2 subs and found the Arendal subs appealing .
I have also looked at Genelec/Adam audio + sub combos but the Neumanns appealed to med somehow. Now that I spent the night reading through the D&D 8C thread I'm back to square one...

1) Concerning studio monitor +sub combo:

IS it really that big of a hassle to get it to sound right? with integrated DSP in the speakers and sub and minidsp Studio (which I will be using as a source). Do I need a lot of acoustic knowledge and countless try and fails or is it more "automated" now. With a busy job and 2 young kids I would prefer to enjoy the music more then the setup. An option is to hire an acoustic engineer which I might do either way as it is a small cost compered to the system total.

2) Concerning studio monitor +sub combo:

There is a lot of money to save on going the Brand X studio monitor + Brand Y non-pro studio monitor path. Will this mess up the integration even more? Is it worth paying the extra bucks to stick with one Pro-brand and its integration options. Eg. Genelec SAM speaker + Genelec SAM sub +GLM or Neumann KH420 +870sub with their own monitor DSP control system?

3) Why not just stick with 2 speakers

This IS appealing, especially when you can place them as close to the front wall as the D&D 8Cs and they have "everything". The new model even has a streamer built in. I feel more comfortable though setting up a futureproof system with 2 subs and 2 satellites. Something in me tells me 2 big sub boxes with in total 4 times 10-14 inch drivers will please my needs more then the mini D&D box working hard when playing loud AND equalizing backfiring...

What are you're takes? anyone owning a KH420 setup? anyone with a medium/big room playing more then 80dB with the 8Cs? Any thoughts in general?
1. Easy, fun to tweak and tune, but easy to get reasonably good result
2. subs are cheap buy two or four
3. everything is better with sub and dsp, kii3 sounds better with subs or bxt for literally everything, 8c is similar to kii3 have had in room and compared without subs. 30x20 foot room 9 foot ceiling here
 
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MikeFromNorway
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Thanks for the support. I understand that treating the listening room is first priority. I am therefor getting an acoustic team to plan/remake my 7x5m living room.
 

FrantzM

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Multiple subs placed on the sides of the room can fill bass room modes in a way that full range speakers in their proper position can't. Full range speakers with multiple subs and room treatment would be the ultimate.... if you can afford it, have the room, and have a very understanding partner.
This is key.
The subs do not have to be the bestest, most linear and most expensive either. Often 3 inexpensive subs will transform a pair of speakers in anything this side of 40 square meter. This necessitate the use of an external DSP in most cases, but remains the best way for ultimate bass in most rooms. it should be reminded that it takes time to get it right. Some will tell on you they did in a few hours, it is often that those people are not factoring the (considerable) amount of time it took them to amass the requisite knowledge and know how.
Peace.
 

audio2design

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The biggest problem with crossing small monitors is not where they roll off, it is the level they can drive before they get crazy distortion. A lot of 5.25 inch monitors have 5%+ THD at >100 Hz near loud-ish but possible listening levels - and those speakers would be really hard to cross over.

+10!

That is why I still have 3 ways in the current incarnation and they are still high passed. It's a custom array, but the multiple similar drivers are for directivity control. Going to build a custom line array for fun. More drivers less power per.
 

Jim Matthews

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As two miniDSP articles were linked to above I'll just add that both fail to cover how to properly do the time/phase matching as far as I'm concerned.
To preface my remarks, I'm old enough to remember the first subwoofers with internal amplification. I'm also easily satisfied that something weighing more than 100 kg is adequately positioned.

***

Perhaps I was fortunate. See figure 5 in the attached MiniDSP LINK.

I used a measuring tape to get the distances from my seating position to the output port of my bass bins.

After a test run (with delay, and without) I preferred the plain signal.

I would emphasize that DSP works best when the attenuation or augmentation is smooth, and subtle. Some of my most frustrating exchanges with Audiophiles that can't be satisfied is over endless tweaks and adjustments to an otherwise enjoyable listening session.

To the OP's query : it is certainly possible to overthink this to the detriment of decent results. Sometimes the difference between "Meh" and good enough is one Scotch and Soda.
 

Jim Matthews

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Guys, interesting discussion but we are FAR off topic here. Please read my first post.
See #30.

This reminds me of an inquiry in a Facebook group on alternate designs for something all respondents insisted I should not make.
 

dshreter

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Thanks for the support. I understand that treating the listening room is first priority. I am therefor getting an acoustic team to plan/remake my 7x5m living room.
This is fantastic! Please keep the thread updated on how things proceed. They should also be able to help with considerations for subwoofer placement and overall system design to inform the monitor / sub requirements.
 

Ultrasonic

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Thanks for the reply. Would you care to expand on your last sentence and share your view/experience?

I wish I could link you to a good 'how to' article but sadly I'm not aware of one. I keep meaning to try to find the time to write something myself.

For best results I would be looking at impulse response measurements to judge time delays to the nearest acoustic period and then use phase plots to fine tune this. The principle issue with not ensuring phase matching like this in the sub/sat crossover region is that the sound from each source can cancel each other to some degree. How much of an issue anyone will get by simply ignoring this will be a mix of luck and how steep the crossover filters are (steeper makes issues less likely).

What won't reliably get this right is trying to set time delays based on physical distances between the sound sources. I say this specifically for subs like the Arendal mentioned where the on-board DSP will introduce a significant delay in its own right. Similarly speakers with on-board DSP will also introduce delays. I've used one pair of active standmounts where the signal arrived after that from my subwoofer, despite the subwoofer being further away.

I realise that doesn't fully answer your question but I'm afraid I don't have the time to try to walk through all of the details right now, and since you're new to any form of acoustic measurements it probably wouldn't be super useful if I did.
 

Bill Brown

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The pros are compelling. Better room integration and smoother bass response as you mention (and in practical terms very, very difficult to achieve without multiple low frequency radiators in the room), but also a wonderful sense of effortlessness and unconstrained dynamics. Good stuff. It is perhaps unintuitive, but there is also an increased sense of "space" or an improved sense of the size of the recording venue.

I don't think it is a huge hassle, and regardless, is definitely worth it. I don't think (based on years of trying) that it is possible to achieve an acceptable level of smoothness in the bass without it. If you are able to hire someone that would certainly be effortless(!), but I bet you could still do it if you chose too.

You don't seem budget-constrained, but by using multiple subs (3 perhaps optimal, the fourth perhaps not adding as much), the work of each is lessened and therefore they don't have to be the ultimate.

Using full range mains is in my opinion optimal, if only because of the increase in low frequency radiators. But I also think it makes integration easier. There are some concepts that consistently come up on this site that I (politely) disagree with that I think should at least be considered:

- Many feel the mains should be high-passed (have a crossover). The only time I would do this is if the mains are dynamically limited in the bass (i.e. small monitors). No way with the K+H would I do this. I would wonder about the D&Ds, but after you add subs you will likely need to have a bass shelf on the total system, and that would relieve them of extreme demands in the bass.

- Many discuss distortion in the bass. Though your system would be stellar in this regard, and that is great, distortion in the bass is very difficult to perceive and is overemphasized here.

- Likewise, there is frequent discussion of the importance of time alignment of the subs to the mains. While always willing to learn, I don't understand the physics of this in the modal region (below the Schroeder frequency of your room), the wavelengths are simply too big.

- Finally, many are concerned about localization of the subs and 80hz seems to be the number people agree on. I also don't think the physics supports this notion. And it is the 90-120hz that I always find the most difficult to get smooth in my room and I don't think I could do it without crossing the subs higher. It is possible I am fooling myself, but I can't locate subs crossed at 120-130hz.

Depending on your placement options, my gut feeling would be the K+H (and is what I would choose). With the D&Ds I would wonder if the tweeter and its fairly low crossover would become the limiting factor (while acknowledging that it may not be a practical consideration in a domestic setting).

Bill
 

sigbergaudio

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The pros are compelling. Better room integration and smoother bass response as you mention (and in practical terms very, very difficult to achieve without multiple low frequency radiators in the room), but also a wonderful sense of effortlessness and unconstrained dynamics. Good stuff. It is perhaps unintuitive, but there is also an increased sense of "space" or an improved sense of the size of the recording venue.


- Many feel the mains should be high-passed (have a crossover). The only time I would do this is if the mains are dynamically limited in the bass (i.e. small monitors). No way with the K+H would I do this. I would wonder about the D&Ds, but after you add subs you will likely need to have a bass shelf on the total system, and that would relieve them of extreme demands in the bass.

(...)

- Finally, many are concerned about localization of the subs and 80hz seems to be the number people agree on. I also don't think the physics supports this notion. And it is the 90-120hz that I always find the most difficult to get smooth in my room and I don't think I could do it without crossing the subs higher. It is possible I am fooling myself, but I can't locate subs crossed at 120-130hz.

Just so I understand you right, you are suggesting to leave the mains fullrange, and also allow the subs to go to 120-130hz?
 

Digby

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Isn't that what Geddes suggests. I don't know where he crosses over the subs, but the mains are huge 15" driver sealed speakers that just roll off naturally. I'm pretty sure he says the more bass sources, the better.
 

Bill Brown

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Also yes. His concepts form the basis of my approach.
Isn't that what Geddes suggests. I don't know where he crosses over the subs, but the mains are huge 15" driver sealed speakers that just roll off naturally. I'm pretty sure he says the more bass sources, the better.
Bill
 

sigbergaudio

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Never heard that work well, but good for you that you are able to integrate your system that way. Not sure I would go with that advice as the first suggestion for someone who are unfamiliar with subwoofer integration, though. :)
 

Bill Brown

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Not sure I would go with that advice as the first suggestion for someone who are unfamiliar with subwoofer integration, though. :)
That could certainly be true :)

And definitely nothing I write is the gospel.

On the other hand, according to some experts that I respect, my approach isn't too far afield. Though perhaps the concepts are not well-known here and so seem "out of the box."

I don't want to clutter the thread, but if curious, one could start here:


For those that want to go deeper only, there is a long thread on the topic. You can see the approach over many years, responses to the many criticisms I see here, etc., weigh the ideas and see what you think:


Bill
 
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