New Servo 15 and my M&K VX100 - Integration Issues

S

Stewart C

Guest
I have had the wonderful M&K VX-100 supplying the bass for my system. I took the opportunity and some say risk in buying a Servo 15.

The Servo 15 is awesome there's no doubt about it, but could I keep the VX-100 and play alonside the Servo 15 ? I have not been able to test this yet as I have just hooked up the Servo 15. I need to let that run in before I hook up both subs to my Denon 11SR.

It seems to me that maybe the subwoofers are so far away from each other in dimensions are dynamics that integration may be impossible.

I love my VX-100 and would love to keep it. If however it does not integrate well with the Servo 15, then I may try and sell it.

Anyone got any advice about the issues I have to resolve.

Regards
 

Ian J

Banned
It probably won't be easy as THX 1138 had problems integrating a Storm 1 and Storm 3 together and mcmullanbrush with his Servo and Yamaha. Ultimately both gave up and sold one of them off.
 

chips

Active Member
Hi Stewart,

I tried to integrate my Servo15 with a Paradigm PS1000. This was not sucessful as the PS1000 was only adding boom.

I then tried with a Yamaha SW-90, strangely enough, this seemed to work better but after a few weeks I came to the conclusion that I was better off with just the Servo.

I believe that we have the same speakers, M&K S-85s & SS150s. Now that I am using just the Servo, It integrates superbly with the M&Ks.

Mind you, the VX-100 is a much better sub than the PS-1000 or SW-90 so it may be worth a try. But i wouldn't be suprised if you end up just using the Servo.
 
C

Chip

Guest
Don't know how you guys can get away with two subs in your room. Mrs Chip wants to kill me for having one. :D
Chip
 
S

Stewart C

Guest
"I believe that we have the same speakers, M&K S-85s & SS150s. Now that I am using just the Servo, It integrates superbly with the M&Ks."


It looks as though we do have the same speakers and they seem to have a new lease of life with the Servo 15.

I just had my mate in the house and we gave it a good testing. He thinks it runs a bit slow with dance music but after a while when the sub was worked hard it seemed to improve. Perhaps I have not run in properly yet, but I can't say I noticed it slow.

Otherwise he says it is wonderful. That is praise indeed as he is very critical about bass (quality and speed)

He has multiple subwoofers in his car and is a bass junkie and he likes his bass ultra fast.

Have you found this with the Servo 15.

By the way I am not a dance fan so it doesn't really matter but has anyone else experienced a slight slowness with fast bass ?

He had test tones down to 10Hz and it coped admirably.

Regards
 

chips

Active Member
Seems fast enough to me. Mind you I don't listen to dance music either.

There is a scene near the begining of Monsters Inc. where they set off a little bomb thing. The integration with the fronts is just awesome, the whole explosion seems to come from the centre of the screen. Very tight, most impressive!!

Mind you, the wife is worried that the house may fall down.
 

Nic Rhodes

Distinguished Member
Originally posted by Stewart C
[BI just had my mate in the house and we gave it a good testing. He thinks it runs a bit slow with dance music but after a while when the sub was worked hard it seemed to improve. Perhaps I have not run in properly yet, but I can't say I noticed it slow.
[/B]

The same old chestnut. Your mate doesn't know what he is talking about. There is no such thing as slow bass but he may never have experienced proper bass before. Bass without distortion.
 
U

uncle eric

Guest
Here is a golden oldie from a while back explaining the myths behind slow bass/ fast bass.

Originally posted by uncle eric
There is a common misconception that small driver equals fast bass and large driver equals slow bass. You often hear reviewers talking about how fast a certain sub-woofer is. If you look at some subwoofer manuafacturers tech blurb they will also suggest the same.

The first thing to understand is that bass itself is not particularly fast. Virtually any woofer, even those with huge heavy high mass cones will reproduce bass frequencies with every ounce of speed present in that bass.

It is in fact nonsense to suggest that small mass woofer cones will give you "super fast bass".

If a driver can produce say 40Hz with low distortion , how fast the woofer starts is almost irrelevant (within reason of course). It only needs to accelerate fast enough to match the rise time of 40Hz at the fastest point along a 40Hz sine wave. If the woofer can do that, it is going as fast as it needs to in order to be as fast as fast can be at 40Hz. The woofer cone does not need to be able to accelerate at 20kHz velocities in order to produce instantaneous 40Hz energy and if you could build a woofer that "fast," 40Hz would sound exactly the same through a "slow" woofer.

Does this mean that there is no such thing as fast bass and slow bass? No. It exists, just not for the reasons and explanations you have been hearing for years, and certainly not for the attributions you’ve read in some magazines. There are reasons to use lighter, lower-mass woofer cones. They just happen to be different reasons than the ones you think you know.

Smaller woofers don’t make faster bass, but they can reproduce higher frequencies than larger woofers can reproduce, and this can be all important when it comes to speaker design. You want your mid-range drivers and the woofer to integrate with spot on symmetry, with perfection and without any problematic interactions throughout their overlap zone.

This is the only reason why you might want smaller, lighter, "faster" woofer cones -- not because they lead to faster bass. Having said that, top quality high end monsters like the Velodynes are so well designed that they have very little problem in achieving this integration or overlap. That "overlap zone" is so incredibly critical to your perception of bass speed that there is little or no tolerance for error. This is a another reason why you should take your time in setting up. The null tolerance for integration error extends to phase, amplitude, frequency, and time. Introduce even slight variations between any part of the woofer and midrange (or panel) overlap zone and you get audible effects in the bass or midbass. This is where all of your perception of bass speed comes from.

In fact, bass speed is virtually 100% a function of how ideally the midrange and woofer are integrated. Bass linearity is just one hugely important factor. Quality bass maestros like Velodyne often talk in terms of their meticulous Linear motion rather than speed for example. Often, you may see a flat frequency-response curve, but the speaker can still sound like it has lumpy bass response because of less-than-ideal phase (or other) relationships between the midrange driver and woofer. Phase can often change with frequency. The woofer and midrange drivers can actually veer off in different directions, phase-wise.

This is especially possible when you mix driver types like panels and dynamic drivers. (Dig up my Martin Logan review from a while back). But large dynamic drivers (woofers) operating at the top of their range and medium-sized dynamic drivers operating at the bottom of their range can often diverge significantly in their phase response. When phase (or other) errors happen, you get comb-filtering effects. This comb filtering results in the complex response of the loudspeaker (to music) being quite different than the response of the speaker when the input is something simple like the sine-wave sweep used to measure "frequency response."
To avoid comb-filtering effects that cause "beating" (reinforcement) and "cancellation" effects in the sound (both are usually partial effects), it is imperative for the phase, time domain, amplitude and frequency performance of the woofer and midrange driver to be "aligned." Get the midrange or woofer a little ahead of or behind the other driver, and comb filtering starts. You can do things to minimize it, but you can’t stop it with certain combinations of driver and crossover.
It is fearfully hard to integrate a dynamic woofer with an electrostatic panel because the two drivers are so different from one another. This is in fact just one of the reasons why ML's cost more than Kef Q1's. Your absolute best shot is using an active crossover with infinitely variable phase/frequency, polarity, time domain and amplitude adjustments. Play with it long enough and you could dial in the response of the dynamic woofer and electrostatic panel to achieve perfection in their integration.

Achieving the same thing using a passive crossover is incredibly difficult. Some designers are getting better as they learn from years of trying, but it is still one of the hardest things to do in audio that I can imagine. Just getting a dynamic midrange and dynamic woofer to integrate perfectly is enough of a challenge. You can hear even small errors show up as speed problems in the bass or midbass. These are the kinds of "character" that will remain with a given set-up no matter what happens.

What about amps, preamps or source components that sound like they make the bass faster or slower? There are many ways for this to happen, but they all involve changing some relationship between the midrange driver and woofer so that the integration changes in some way that manifests itself as "faster" or "slower" bass. The component itself is not producing faster or slower bass; it is creating an interaction with the speaker crossover that results in you hearing that. Some of those interactions will be consistent from system to system, while others will be chameleon-like, changing from "fast" bass in one system to "slow" bass in another. Yet if you measure the component electrically, there is nothing in its measurements that indicate that it is anything but perfect, speed-wise, at bass frequencies. It only takes a small loudspeaker-dependent phase shift to occur when using a particular amp to make it so. This would be harder to have happen in a preamp or source component -- their signatures will tend to be more consistent from system to system.


What about bass detail?
Why is it that one speaker has so much more bass detail than another? This to is strictly driver integration and NOT the quality of the woofer itself, as you may have heard.

Let me put this another way. You all know what a water-colour painting looks like. Blotchy with colours running everywhere. In fact, most of the time, until the artist proceeds to "define" the edges of his/her work with something finer like a thin pencil for example, it doesn't look like much at all. In much the same way, bass detail comes from the finer (pencil like) midrange driver. But your ear/brain is so completely fooled by this complex interaction of midrange and bass sound that you believe that it is strictly a bass-related thing. It isn’t, and you can prove it.
When you have some time to kill, un-plug your main speakers and play something through your subwoofer alone.
You won’t hear anything vaguely resembling speed coming from that slow, soggy-sounding, plodding subwoofer. It has no detail and no speed whatsoever when heard all by itself. However, once re-integrated, if your system is set up well, the subwoofer will appear to have tons of detail. But, and a big but, if the integration is off a little, the bass will sound fast or slow too. All of that sense of speed and detail is coming from the mid-range, not the bass. That is why the integration of the mid-range and bass is so critical to getting a good-sounding set-up.
 
U

uncle eric

Guest
Another thing to bear in mind: live bass does not sound fast or slow; it just sounds like bass associated with whatever instrument or other source is creating it. The concept of "fast" or "slow" bass is a loudspeaker and audio-system-related thing. You could probably devise a live demonstration to show how the midrange of a string bass can affect the perceived quality of the bottom end of its range (and for all I know, the best musicians may use this to further extend their emotional reach in their playing). But in day-to-day listening situations when you hear live music, I doubt you’ve ever thought about the "fast" or "slow" bass that you were hearing. That’s something that happens at home in the reproduction chain, and it’s an artifact of integration errors. Remove the integration errors and the bass loses all sense of being fast or slow, just like live bass.

For you this means something profound. If you hear a system (hopefully not yours) that sounds "fast" or "slow" in the bass, enough that you have noticed anyway, that system has a problem. It might be fixable if the bass is coming from a subwoofer with lots of adjustments. But most of the time, it will take some minor or major change to remove the fast or slow character. For example, when using Sat's, even changing say a stand, shelf or resting place can affect apparent bass speed because it changes the midrange of the electronic component or loudspeaker it is used with, not because it couples (or isolates) to the floor or shelf better. The different "shoe" simply changes the character of the midrange a little bit, and because the midrange and bass quality are so tightly intertwined, the quality of the bass changes too, even though nothing specifically changed in the bass itself.
Simply put, my feelings are that low Distortion and well controlled linear motion are hugely important factors.
 

John DB

Active Member
Originally posted by Stewart C


By the way I am not a dance fan so it doesn't really matter but has anyone else experienced a slight slowness with fast bass ?

He had test tones down to 10Hz and it coped admirably.

Regards

Hi Stewart,
I like a bit of dance music and have found no slowness whatsoever with my pair of S-15's. At first I had the wick turned up a little high and they were making themselves too 'obvious' if you know what I mean. So I Re-calibrated and now they are just godamn beautiful, can't stop listening to music at the mo :D

With previous subwoofers I never could find the correct balance, sounded great with a particular track and then either too light or boomy with the next. No such problem now, everything is tight, deep and seamlessy integrated with the S-85's.
 

dts_boy

Well-known Member
yeah, you need to get rid of one of them and stick with the better performer. as a favour, i will give you £100 for the servo and let you enjoy the better sound - don't go tellin everyone that i do favours like this though!:D
 
S

Stewart C

Guest
To the guys with the Servo 15's

Thanks for your comments (thanks to all, Eric you're a star, now I need to study what you say).

Back to the Servo 15 owners. Do you use the X 30 controllers to help integrate your subwoofer with the other speakers or is your sub a stand alone set up, using the insternal crossover of your amplifier/receiver.

From what Eric is saying the phase is one aspect (of many) that can affect subwoofer/satellite speaker integration. As I do not have the X 30 controller, I am unable to tweak the phase to see if that improves things.

Regards
 

chips

Active Member
Back to the Servo 15 owners. Do you use the X 30 controllers to help integrate your subwoofer with the other speakers or is your sub a stand alone set up, using the insternal crossover of your amplifier/receiver.

I'm certainly not an expert on these matters, but for what it's worth I found that altering phase via the X30 did help when trying to integrate two subs.

Now that I am using just the servo I'm not sure it is necessary. I still have it in circuit but don't find that phase setting makes a lot of difference to the overall sound. But I leave it at about 120 degrees which was the best setting with two subs. The servo is near the back of the room firing across the room (only place it will fit). When I was using two, the second sub was at the front with phase set to 0 degrees.

It's really difficult to set phase with only one sub as my amp will only output sub test tone on it's own.

Hope the above makes sense.
 

John DB

Active Member
I tried the X-30 at first and found that the phase control wasn't needed and 80hz was the sweetest crossover point anyway so I removed it from the chain. Both my subs are positioned under my screen firing forward into the room.

Although its not a lot of help to you Stewart, the reason I bought 2 identical subs is purely because in the past I have tried to integrate a single sub with my s-85 80hz satellites and failed miserably :( This might be down to the rooms characteristics or my inexperience I dunno.

Maybe you should just bite the bullet and get another minty S-15 from RS's latest consignment swiftly and direct form the warehouse before the remaining few start getting kicked around the RS branches, turning em into Eric/Chippys favourite firework :D

Nothing to lose...


P.s Chippy
If my 2 hadn't turned up on the day I happened to quit the 40-fags-a-day habit (1 week w/out now :)) then believe me, Mrs DB would have had my Gallo's.
 

The latest video from AVForums

Oculus Quest 2 VR headset + Rotel A14 MkII Amp Reviews & Best of the Month
Subscribe to our YouTube channel

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom