[G Georgopoulos]

Russell are you engineer?please tell me 

[maty]

Spatial Audio factory tour, Hologram M4 review

-> http://www.digitalaudioreview.net/2016/04/spatial-audio-factory-tour-hologram-m4-review/

[jtwrace]

I have to take exception.

All a balanced configuration accomplishes is greater freedom from hum and the like, due to the inherent rejection of common mode signals, like EMI induced hum. This can be an advantage only when hum is a problem or is audible, otherwise the signal suffers twice the degradation needlessly. I say twice the degradation because it is impossible for a signal not to be degraded to some extent merely by passing through any electrical device, be it transistor, capacitor, resistor, transformer winding or whateverr. Since fully balanced involves twice the number of devices for the signal to pass through, the resulting distortion from this is doubled, all other factors being equal.

Is that technically better? Not in my books, but it is a very common misconception.

In recording studio work it is more likely to be necessary and the convenience of not having to trace and deal with hum is often worth the degradation, but even in that environment the same misconception is widely held. In fact I had a lengthy online debate with an otherwise extremely well informed engineer about this very subject a few years ago.

Part of the problem is that balanced connectors look so much more professional than the humble looking (and flawed-in-its-own-way) RCA connector. They click-lock into place and all that good stuff, but if you are in search of the ultimate sound, you want to keep the signal path free of needless complications. Hum is seldom an insurmountable problem in the home, but manufacturers know the cachet associated with balanced and are only too pleased to service that perception.

I have to take exception too.  If you look at the measurements of my equipment running balanced mode, there is an obvious advantage over SE.  That's why I do it...not for special connectors or any of the typical audiophile crap. 

Back to Spatial though.   

[DaveC113]

I have to take exception.

All a balanced configuration accomplishes is greater freedom from hum and the like, due to the inherent rejection of common mode signals, like EMI induced hum. This can be an advantage only when hum is a problem or is audible, otherwise the signal suffers twice the degradation needlessly. I say twice the degradation because it is impossible for a signal not to be degraded to some extent merely by passing through any electrical device, be it transistor, capacitor, resistor, transformer winding or whateverr. Since fully balanced involves twice the number of devices for the signal to pass through, the resulting distortion from this is doubled, all other factors being equal.

Is that technically better? Not in my books, but it is a very common misconception.

In recording studio work it is more likely to be necessary and the convenience of not having to trace and deal with hum is often worth the degradation, but even in that environment the same misconception is widely held. In fact I had a lengthy online debate with an otherwise extremely well informed engineer about this very subject a few years ago.

Part of the problem is that balanced connectors look so much more professional than the humble looking (and flawed-in-its-own-way) RCA connector. They click-lock into place and all that good stuff, but if you are in search of the ultimate sound, you want to keep the signal path free of needless complications. Hum is seldom an insurmountable problem in the home, but manufacturers know the cachet associated with balanced and are only too pleased to service that perception.

+1 

But DAC chips are frequently balanced as it makes implementation easier, and switching amps are all balanced too... so if that's your system it makes more sense to me to use a balanced preamp nad keep it all balanced in to out.

[DaveC113]

Russell are you engineer?please tell me 

Please tell me why you post negative comments that add NOTHING to threads all the time? I'm going to start reporting these kinds of posts because it's gone on forever and I'm getting really tired of the snarky attacks you post in almost every thread. And ridiculously, you follow up with some smiley emoticon to cover the blatantly negative posts.

Here's a suggestion: Don't post unless you have something constructive to add to the thread. IMO, your negativity is against TOU and seriously degrades the quality of this forum.

[dspringham]

Has anyone had the opportunity to compare the M3 and M4 side by side?

Are we only talking a difference in low end extension (32hz. vs 40) or are there other significant aural differences. The Turbo-S version of each seems to use the same compression driver so I would expect the mid/upper frequency performance to be similar as well.

I have a fairly large open concept (living/dining/kitchen) space to fill but in terms of where I position my equipment I prefer the form factor of the smaller M4. Would the M4 with sub reinforcement provide most of the performance of the M3?

However, considering that there is only $500 difference between the Turbo-S versions of each, which really represents the best value proposition?

Comments?

[Don_S]

Has anyone had the opportunity to compare the M3 and M4 side by side?

Are we only talking a difference in low end extension (32hz. vs 40) or are there other significant aural differences. The Turbo-S version of each seems to use the same compression driver so I would expect the mid/upper frequency performance to be similar as well.

I have a fairly large open concept (living/dining/kitchen) space to fill but in terms of where I position my equipment I prefer the form factor of the smaller M4. Would the M4 with sub reinforcement provide most of the performance of the M3?

However, considering that there is only $500 difference between the Turbo-S versions of each, which really represents the best value proposition?

Comments?

Adding a subwoofer to the M4 makes the price difference disappear.

[dspringham]

True Don_S, however the sub(s) are already available and would not be new purchases. I guess I'm really wondering if an "augmented" M4 can approach 90% of the M3.

[sonicboom]

Please tell me why you post negative comments that add NOTHING to threads all the time? I'm going to start reporting these kinds of posts because it's gone on forever and I'm getting really tired of the snarky attacks you post in almost every thread. And ridiculously, you follow up with some smiley emoticon to cover the blatantly negative posts.

Here's a suggestion: Don't post unless you have something constructive to add to the thread. IMO, your negativity is against TOU and seriously degrades the quality of this forum.

+1

All this, from a guy that purports to be an "engineer" all the while exhibiting a total lack of understanding of the basic nature of the devices that he supposedly designs with!   

http://www.audiocircle.com/index.php?topic=126934.120

Scroll down to the middle of the page.

[Ric Schultz]

I am sure these speakers are great and fine just as they are.....however, I am a tweaker.....never satisfied till I wring every once of goodness out of something.  If I were going to order one of these.....and I probably would if I were looking for speakers in this price range....I personally don't see anything better out there......here is what I would order and do:

1. Order the speakers with external xovers and no wires connected to the drivers.  This allows you to change the xover parts to better ones (no way at this price point can he use the worlds best parts).  You can then change the wires to the drives to better sounding wires and also hardwire directly into the xover eliminating the input binding posts.  All of these changes including have a damped external xover (off the floor) would make a substantial improvement. 

2.  I would damp the back of the big woofs with EAR SD40AL.  The woofs have a stamped frame and killing the resonances of the frame will result in cleaner sound.

3.  Make a rear brace that runs from the base all the way behind each driver and attach it to the top of the baffle.  This will stiffen the baffle and make for faster transients.  The original version of the M3 had a brace done like this but he dropped it (probably for money reasons....maybe for sonic reasons....was kinda thick).   You don't need the brace that thick.....even just 1.5 inches would be great (I would use 13 ply plywood with green glue in between two layers).

Of course, probably none of you would want to do these things: voids warrantee, loss of resale value, fear, does not look as sweet, etc.  However, for that one person that can understand what I am saying and wants to take this speaker technology to another level.....well, have at it.

Yes, all of these tweaks have been listened to by myself and countless others.  They all work.  Everything is made to a price point.  Spatial has more expensive speakers with better drivers, xover parts and baffles.  I prefer to take something affordable and upgrade it myself.....a lot of fun and very rewarding. 

Now back to your regular programming.

[Manolo]

One easy thing you can do is to tighten all the driver bolts..... in my M4's they were not really tight and one or 2 were really loose..
Don't go overboard though!

[maty]

2.  I would damp the back of the big woofs with EAR SD40AL.  The woofs have a stamped frame and killing the resonances of the frame will result in cleaner sound...

-> http://tweakaudio.com/EVS-2/Modding_the_Emerald_Physics_spe.html

-> http://diyaudioprojects.com/Drivers/Fullrange-Modifications-Tweaks/

[maty]

and

-> https://nauscopio.wordpress.com/2011/06/28/hum-mejoramiento-con-tecsound-sy-70-y-fibra-de-vidrio-de-cajas-denon-de-tres-vias-y-bass-reflex-trasero-1991/#comment-9648

Magnet and frame all coated! I let the compound dry over-night so it’s completely cured. VB-1 is non-toxic, it’s not harmful to get on your skin, and there is absolutely no fumes or nasty smell to deal with. I get it directly from Cascade, so at the wholesale price per gallon, the extra cost per application (speaker cabinet or woofer frames) is minimal. The benefits are much greater than the small initial cost. I used to use adhesive-backed asphalt or vinyl based sheets on the interior walls of my cabinets. As far as damping properties go, the VB-1 is superior. It also sticks better, and is easier to apply.

[G Georgopoulos]

Please tell me why you post negative comments that add NOTHING to threads all the time? I'm going to start reporting these kinds of posts because it's gone on forever and I'm getting really tired of the snarky attacks you post in almost every thread. And ridiculously, you follow up with some smiley emoticon to cover the blatantly negative posts.

Here's a suggestion: Don't post unless you have something constructive to add to the thread. IMO, your negativity is against TOU and seriously degrades the quality of this forum.

You have misunderstood my post,i wasn't been sarcastic but the opposite,and my question implied compliment to Russell for his eloquent social and technical posts...

thanks for your personal attack

[Audiophile58]

I have the M3Turbo and  s compression driver. I have greatly improved the Xover Clayton did a excellent
Design I just used  higher end parts .for resistors swapped out yhe Mills to Mundorfs top Supreme instead of one  30 ohm , 2-150 cut the ends off and soldered Neotech  Single crystal copper leads,
On top the Big 1.5 capacit or did have the new Mundorf supreme Evo silver gold oil but slightly tipped up
But great detail and resolution. For balance the Audyn True Copper capacitor  I like better then the Jupiter
Or Basic Duelund for balance, the Duelund Cast is Better but is huge and 4 the cost.
These Audyn Copper caps are Huge I took 4 pieces of plastic tubing and 2.5 inch screws did the soldering
Then screwed back in it sticks out the back 2 inches no big deal. Also I placed Dynamat all over the back
This increased performance in evenew better focus.  Also AVM fluid applied yo the crossover all leads and solder joints wires except the resistor even better focus look it up Audio Vibration Magic give it a hour to dry

[poseidonsvoice]

Hopefully you fellas have measured the crossover transfer function curves (impedance and phase), and at least on axis response curves before venturing on this tweakathon and...oh...calibrated LCR's would be a nice touch as well 

Best,
Anand.

[Ric Schultz]

If you upgrade a stock xover using the same values of parts (including size of coil) then you will have no differences in any measurement.  Most all who have done mods to xovers have no knowledge of technical things but all will tell you that better parts sound better.  It is very simple to replace parts.  If you use a bigger gauge coil then stock then its impedance may effect frequency response slightly.  But even then it is minor compared to the better sounding part.  Don't be scared away by the techies.....very simple....."even a cave man can do it".  However, it is always good to measure a speaker before and after mods.  Measurement mics and software cost very little.  Again....cave man friendly.

[rebbi]

Adding a subwoofer to the M4 makes the price difference disappear.

Tell us more, Don_S! Are you running your M4's with a sub, and if so, I'd love to hear the details. I've been thinking of going that route because the M3, I'm afraid, would overwhelm my little room (visually and sonically).

Thanks in advance!

[Don_S]

Tell us more, Don_S! Are you running your M4's with a sub, and if so, I'd love to hear the details. I've been thinking of going that route because the M3, I'm afraid, would overwhelm my little room (visually and sonically).

Thanks in advance!

Rebbi,

I do not have any Spatial.  I was merely commenting on someone comparing prices  between an M4 with sub and the M3 alone.

[rebbi]

Rebbi,

I do not have any Spatial.  I was merely commenting on someone comparing prices  between an M4 with sub and the M3 alone.

Ah, my goof, sorry.