running dual speakers per channel in stereo, WTF!?

[khaliss]

hi all,

I'm kinda OC & tend to have thoughts of "what ifs" for this hobby... I've been experimenting with the idea of running dual stereo speakers. My main reasoning behind this is that I love the sound of Martin Logan electrostatic speakers, but given that I have the Electromotion ESL speaker (entry-level, smaller panel)... the moment I stand up or not in the center (sweet-spot), the sound just collapses. Although my listening room is small, I still want to be able to hear the full range on whatever is playing, when I'm moving about in the room... and I don't have the budget for the larger electrostatic speakers. So with that said, I found a deal on a pair of Monitor Audio Silver RS6 speakers (FB marketplace). These were well reviewed back in its time, I remember listening to a pair of RS8s (larger version) over 15 years ago at my friend's house, & was thoroughly impressed.

So now, I've changed my setup in such a way that there are now two speakers per Front (stereo) channel. Again, the idea is to compliment the main electrostatic speakers with conventional speakers... so I still get that sweet electrostatic sound when I'm sitting on my recliner (sweet spot), while still hear the full range while I'm moving about. I've read about (& watched videos) about the likely pitfalls about having two speakers per channel (comb filtering, audio dips, etc)... but now that I have the ability to do my own measurements (with REW) and that in theory, given that they are very different speakers (electrostatics have a narrow sound-wave dispersion for mids/highs), and how I have another pre-amp (in between the AVR & the main power amp)... it might change the sound characteristics between the audio output from the electrostatics vs the RS6s... maybe it might not be too adversely affected by comb filtering, etc... I mean why not, doesn't hurt to try, right?

Pic of actual setup.

So after setting things up as shown here... first thing I made sure was that electrostatics have just a little bit more gain (in output) than the RS6s, this was easily adjusted using the DoukAudio T8pro EQ/preamp (this was measured in REW too). After that, I then proceeded with getting them to work together... I probably changed at least 5 positions on the RS6s... re-measured, listened, tested, rinse-repeat. As a result of the position that sounded best, here is the result of the measurements from my sweet spot:

LEFT channel (green = electrostatics only || red = both speakers working together)

RIGHT channel (yellow= electrostatics only || blue = both speakers working together)

Note that the electrostatics are toed-in per Martin Logan's recommendations... I estimate close to 15 degrees(?) they are about 8 feet apart, and my recliner is dead center (about 8ft away). The RS6 speakers have no toe-in, just pointed straight to the backwalls.

Conclusion: Tonally, it sounds very similar (compared to just listening with the ESLs alone)... detail seems to be about the same, but the sound-stage seems to have expanded a notch (not sure if my ears are just playing tricks on me)? I mean the sound is already fantastic with ESLs only, so if anything the improvement is pretty minimal from the sweetspot. HOWEVER, the most noticeable difference is when I'm standing up or moving around... I get most of the sound still intact! Also, when listening at lower levels (65-70db range)... the sound still sounds full(?) Overall, I'm pretty happy with the results... and I'm rather satisfied with this strange setup for now LOL

Thoughts/feedback appreciated =)

 

[beeface]

today I learned you can buy an "Accuphase" amp from Aliexpress

 

[kemmler3D]

If you like how it sounds I'm not going to try to talk you out of it... the soundstage getting bigger could be as simple as the sound coming from a more widely spaced set of speakers. Comb filtering will not show up unless you look at the unsmoothed graphs, you can use REW's graph math tools to compare results from 2x or 4x speakers.

Looking at your setup and the measurements though, it's crying out for some room correction. You've got multiple capable subs, but are still suffering with a 20dB swing from 20-200hz. Since there is a PC in the mix it's easy enough to at least correct the output of that using EQAPO. And you've already got your REW sweeps so the job is 90% done already.

 

[khaliss]

If you like how it sounds I'm not going to try to talk you out of it... the soundstage getting bigger could be as simple as the sound coming from a more widely spaced set of speakers. Comb filtering will not show up unless you look at the unsmoothed graphs, you can use REW's graph math tools to compare results from 2x or 4x speakers.

Looking at your setup and the measurements though, it's crying out for some room correction. You've got multiple capable subs, but are still suffering with a 20dB swing from 20-200hz. Since there is a PC in the mix it's easy enough to at least correct the output of that using EQAPO. And you've already got your REW sweeps so the job is 90% done already.

the 3 LFE subs are actually disabled when I ran this measurement... I configured the front Left/Right speakers in full range. I will later post the graph with the LFE subs are in play (which would of course look much better). The smoothing is in 1/6, will post the Var smoothing as well later. I tried doing EQAPO correction in my earlier versions of this setup, it sounded good, but I thought it sounded too flat. I love my bass, so I don't mind a bit of coloration at all... I want to enjoy my music & movies, not looking for the true & super accurate sound reproduction.

The dips you are seeing is my listening room, cuz it's not a real/dedicated listening room. It's more of a spare bedroom/playroom that doubles as a listening room. I think my racing sim rig is what's causing the dip in the low bass region from the right channel, it's right in front of the RS6 right speaker & reflecting the sound waves, prematurely clashing with the right ESL speaker(?)

 

[kemmler3D]

I think my racing sim rig is what's causing the dip in the low bass region from the right channel, it's right in front of the RS6 right speaker & reflecting the sound waves, prematurely clashing with the right ESL speaker(?)

First of all, nice bike and nice racing rig!

Secondly, that all makes more sense that the subs were off for these measurements.

Thirdly, the rig probably isn't doing much to the bass. Low bass is not directional, in the sense that it spreads out almost spherically from the speaker. Low frequencies have very long wavelengths (longer than the speaker or even the entire room) so they behave differently. In all likelihood the dips would stay more or less where they are regardless of where the racing rig is.

You don't have to have flat-flat bass if you EQ with REW / EQAPO... you can define a house curve to taste, and enjoy however much bass boost your subs will support, but also remove the dips from it. This is pretty common, a lot of people enjoy elevated bass to an extent.

To me it's so worth it, I can't stand (now) when I'm listening to something with a strong bassline and one note is much quieter than the next due to room modes.

 

[RayDunzl]

I use my 'stats and big amps for critical listening.

The Daily Drivers are a pair of JBL LSR 308, located adjacent to the center of the panels.

I don't use both simultaneously.

 

[beeface]

the 3 LFE subs are actually disabled when I ran this measurement... I configured the front Left/Right speakers in full range. I will later post the graph with the LFE subs are in play (which would of course look much better). The smoothing is in 1/6, will post the Var smoothing as well later. I tried doing EQAPO correction in my earlier versions of this setup, it sounded good, but I thought it sounded too flat. I love my bass, so I don't mind a bit of coloration at all... I want to enjoy my music & movies, not looking for the true & super accurate sound reproduction.

The dips you are seeing is my listening room, cuz it's not a real/dedicated listening room. It's more of a spare bedroom/playroom that doubles as a listening room. I think my racing sim rig is what's causing the dip in the low bass region from the right channel, it's right in front of the RS6 right speaker & reflecting the sound waves, prematurely clashing with the right ESL speaker(?)

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hobbies_guy.jpeg

 

[khaliss]

I use my 'stats and big amps for critical listening.

The Daily Drivers are a pair of JBL LSR 308, located adjacent to the center of the panels.

I don't use both sumultaneously.

i get that, what I'm doing here is definitely not a great idea... but hey, I don't mind experimenting & going outside the box. For some reason it's clicking for me, so for now I'm gonna keep going in this direction LOL

 

[kemmler3D]

i get that, what I'm doing here is definitely not a great idea... but hey, I don't mind experimenting & going outside the box. For some reason it's clicking for me, so for now I'm gonna keep going in this direction LOL

It's not the craziest thing I've ever seen, it's conceptually maybe a couple doors down from a bipole speaker. People really like the Bose 901 and this isn't any wackier compared to a typical monkey coffin. It's technically questionable for sure, but if you like it, what more can we say?

 

[DVDdoug]

If it sounds good, that's what counts!!!

But "technically" you've probably got some strange phase interactions. You'll get phase differences as the soundwaves combine from the different distances, and the crossover usually introduces phase shifts and eventually a 180 degree phase/polarity inversion. The midrange in a 3-way is usually polarity-inverted and the tweeter in a 2-way.*

So if you have speakers with different crossover frequencies (or an electrostatic with no crossover) the phases won't match at all frequencies and you can get cancellations (or partial cancelation) at some frequencies.



* This is done because the low-pass to the woofer creates a phase-lag at (and above) the crossover frequency and the high-pass creates a phase-lead in the midrange or tweeter. Flipping the polarity of one driver helps to keep them in-phase at the crossover frequency where they are both operating together.

 

[beeface]

a couple doors down from a bipole speaker

you're right. he should go the distance and face the monitor audio speakers in the opposite direction

 

[khaliss]

ok, I re-measured just now just to make sure last night's graphs were no fluke. Here are the results (VAR smoothing):

LEFT channel
* Blue (electrostatic speaker only)
* Green (both speakers)

RIGHT channel:
* Yellow (electrostatic speaker only)
* Red (both speakers)

I mean, just by the graphs... which would I pick(?)
-edit- Let's ignore how bad my untreated & cluttered-with-stuff room is (with laminate floors LOL), I promise to work on room acoustic treatments later on haha

 

[Chrispy]

Can't imagine bothering myself. Making different setups/systems perhaps. Back when I bought my first Advent Originals there it was a "thing" to double them up. In demos never found much of an advantage so never went that way....

 

[khaliss]

Can't imagine bothering myself. Making different setups/systems perhaps. Back when I bought my first Advent Originals there it was a "thing" to double them up. In demos never found much of an advantage so never went that way....

I totally get that for most people, & if I didn't have the extra gear... I wouldn't have bothered too. But in this case my ESLs would only shine when I'm in the sweetspot... so I decided to try something crazy, just cuz I can

 

[Chrispy]

I totally get that for most people, & if I didn't have the extra gear... I wouldn't have bothered too. But in this case my ESLs would only shine when I'm in the sweetspot... so I decided to try something crazy, just cuz I can

I have plenty of extra gear, just don't combine in terms of dual 2.0 use.

 

[khaliss]

just got a new DAC, Topping E70 Velvet... I'm done with measurements, now I'm gonna try to listen to some tracks & compare single vs double

 

[khaliss]

I have plenty of extra gear, just don't combine in terms of dual 2.0 use.

I understand the concept has no appeal to most audiophiles as it defies what has already been established (dual stereo speakers don't work well), but I'm not really an audiophile or purest... I'm just a curious guy lol

 

[Chrispy]

just got a new DAC, Topping E70 Velvet... I'm done with measurements, now I'm gonna try to listen to some tracks & compare single vs double

You're going to waste time "listening" to different dacs? Seriiously?

I understand the concept has no appeal to most audiophiles as it defies what has already been established (dual stereo speakers don't work well), but I'm not really an audiophile or purest... I'm just a curious guy lol

You realize that self described "audiophiles" are are the least reliable in this field?

 

[khaliss]

my 1st DAC was a very basic one, I ordered an E70V just because I got it for a great price & it seems to get great reviews everywhere... are you saying these DACs don't really make a difference?

 

[khaliss]

You're going to waste time "listening" to different dacs? Seriiously?

You realize that self described "audiophiles" are are the least reliable in this field?

I mean most long time members consider themselves as audiophiles, no? You have a "senior contributor" tag & sound like you know a lot... don't you classify yourself as an Audiophile? (no offense, a real question)