Baffled As To Why The Speakers Sound So Good!

[AllenB]

...music does not seem to originate from the boxes any more, yet I can define the placement of almost every instrument in 3 Dimension!

So can I, but I approach it the opposite way by filling my room selectively. Your spaciousness has helped you to get these qualities but it is not the reason for them.

I did some experiments with wiring ordinary speakers in series, and I always got excellent results. Very smooth and valve-like sound. You get similar improvements with bridged mode amplifiers. 😀

Lower damping factor?

 

[AllenB]

I just recalled an experience I had that relates to this. It was quite some time ago and I stumbled upon it by accident. Something I did gave me the biggest room involvement, realistic soundstage, and a scary overpowering presence with lower mid weighting. It was instantly the best I'd heard, and almost as quickly I hated it.

I tried to improve on it and lost that sound, I couldn't remember how to get it back and was disappointed that I couldn't. Over time, It came to me what I must have done. I must have created a broad on-axis cancellation which left me with only the room contribution. I was running a three way at the time and my crossover points were probably an octave or two either side of 1k. Maybe any ordinary stereo would do something similar if the speakers were turned about-face?

 

[planet10]

Dave, could you please advise the loudspeaker configuration, considering the following:
"D'Appolito Configuration" Positive goes to Amplifier Positive, Negative to Negative of Inverted Loudspeaker.
Positive of Inverted speaker to Negative of speaker that is 180 degrees to the "D'Appolito Configuration"
Positive of the "180 degree"" speaker to the Negative to the speaker that is at 65 degrees to the "D'Appolito Configuration"
Positive of the "65 degree" speaker to the Negative of the Amplifier

Note: This arrangement in no way ressembles a "D'Appolito Configuration", which is an MTM.

Described above would be classified as weird (someone check make sure i wired it as the instructions?)

Front speakers out of phase, their bass cancels and everything higher will be phasey. The back & the side ones are in-phase with the inverted speaker so they will produce bass.

4 speakers wired in series means nominal 32 ohms (if 1 speaker is 8). Amp will have lower dustortion (and maximum power)

dave

 

[Bigun]

Something like this happened to me once a few months ago. In my stereo set up with the two speakers very close to each other I had my FM tuner source on MONO and accidentally connected one of the speakers out of phase. Since it was mono I wasn't expecting any spatial effects. Instead, there was a super-strong sense of the music floating around in space, far more so than any stereo signal has generated with the same set up. It was the most holographic sound I've experienced. Pitty it's artificial.

 

[cyclecamper]

Sounds to me like you're getting some of the effect of a dipole, activating more (and more complex) room modes for a better average response, and getting some of the 'Bose' wide ambient field perhaps without the usual expense of losing the rasor-sharp and very coherent central integrated image (usually due to the near-field reflections on side walls). I'm thinking perhaps the side nearfield reflections we know are so damaging to the soundstage are diminished due to the out-of-phase speaker to its near side wall? Just so you still get good bass; you might limit the bass cancellation on those side-facing speakers. And keep the speakers away from side and back walls; how big is your room?

If you like stuff like a wide sound field, and have a lot of speakers, you should try one more experiment you might enjoy. On each side, add yet another front-facing speaker, but drive it a little less with a reverse-phase signal from the opposite channel. It accentuates the differences between the channels, and widens the soundstange. Polk had some name for it...which I can't remmber. Carver did the exact same thing but electronically with his 'sonic hologram' feature on his '70's Phase Linear preamps (and more efficiently mixing the signals electronically instead of mixing the sound from seperate speakers in the air. The sound seems similar to the 'SDS wide' setting on my TV. But you should try it, you might like it. But if you do try it, you might limit the bass and volume on these additional front-facing speakers so that any mono bass doesn't all cancel.

Sounds to me like you're having fun; enjoy. IMHO people who like dipoles have found an efficient route to their personal nirvana, but experimenting with multiple inphase and out of phase speakers my give more control and it might be possible to find even better performance in a given room.

Personally, I prefer a known source with controlled dispersion and treat the room. That's not always possible.

 

[jsa_ind]

Thanks everybody so what I am hearing is holographic sound but not true Stereo sound...but it sounded so gooooooood.....sigh...

Thanks Dave for the diagram could you please advise the wire connections in series if SP ISP & 65 SP are in phase and RSP out of phase & the connections with all in phase

BTW each speaker is rated at 4.00 ohms

Also is there any series and/or parallel connection with this loudspeaker placement ( Inverted, 65 degrees & 180 degrees) that would fit a conventional speaker configeration

 

[jsa_ind]

Say Cyclecamper that is a new one "but drive it a little less with a reverse-phase signal from the opposite channel" thanks!

Could you please advise how to go about the same? I d have an extra Dynaudio 52 lieng around...though I will not attempt to stack it on the present stack!

Thanks,

 

[cyclecamper]

MONO ... connected one of the speakers out of phase.

Once I met a guy from Sure responsible for many of their cartridge designs. I was doing semi-pro PA at the time. He told me that he could detect out-of-phase speakers in an instant. I would use mono and switch phase on one side to compare, looking for a lack of bass one way. But he just paid attention to the soundstage. As he put it, when one speaker is out of phase it sounds like the sound comes from everywhere EXCEPT right in the middle between the speakers. Properly wired, I've found there's usually a good strong central 'image'. Once I'd learned to listen, it became obvious...and easy to pick out occasional effects where Jimi Hendrix would momentarily be out of phase during a pan... I used to hear more 'mistakes' in commercials where one side would be out of phase, but that seems more rare now. But yes, it IS 'trippy'. Just not necesarily accurate reproduction. Perhaps a useful effect for a DJ.

My recent ambition is to learn to hear the effects of the room more. I was really impressed with the improved "definition" of the bass with good room treatment. It wasn't just more pleasant without nasty resonances; the actual bass lines were consistently more discernable.

 

[cyclecamper]

Another fun thing to try when you have a LOT of amps and speakers about. Put a second set of subwoofers at the back wall facing you, but wired OUT of phase. Kind of an active absorber.

 

[cyclecamper]

PA systems sometimes have extremely convoluted arrangements of multiple speakers in and out of phase, as an expensive way to control the radiation pattern when the pattern is really critical for some high-priority reason (sometimes involving feedback or neighbor issues).

 

[system7]

This is probably going to pose more questions than answers...😀

There are two ways to create a filter. One with an input resistor as we always did at radio frequencies, and one without, as we tend to with loudspeakers:

An externally hosted image should be here but it was not working when we last tested it.

LC Filter Design
2-Way Crossover Designer / Calculator

I have always considered the ones with resistors to be more musical, but of course it raises damping issues with bass units (which are solvable...).

How does this tie in with jsa's observation of wiring his dynaudio speakers in series? They certainly have the simple crossover and low inductance (which you can build into the filter) that can make this sort of arrangement work:

An externally hosted image should be here but it was not working when we last tested it.

This is called serendipity. Good fortune by chance! 😎

Oh, BTW, in the second diagram the ELECTRICAL response is second order Linkwitz-Riley at the second woofer as John Kreskovsky pointed out. This is interesting in itself, because two cascaded butterworths give a Linkwitz_Riley. Don't worry about it! It still works. LOL

 

[Chronus]

system 7,
with regard to the second woofer arrangement. I am considering trying this my bass guitar rig. I wanted to use two 12" bass drivers in one enclosure,but get them with different frequency response characteristics. One shifted to the high side ( up to 2khz ) and one dipping into the low side ( down to 30 hz ). The question is would this filter be possible with high power ( over 200 watts per driver )?

 

[JamesTRexx]

This setup reminded me of this topic; http://www.diyaudio.com/forums/multi-way/177403-linkwitz-orions-beaten-behringer-what.html
Everyone was talking about the Orion and Behringer, yet it was the cheap Eickmeier omnidirectional that created the best auditory scene.
I believe omnidirectional with a decent distance from the walls will deliver the best soundstage with a stereo setup. This I noticed while experimenting over the years.

 

[system7]

system 7,
with regard to the second woofer arrangement. I am considering trying this my bass guitar rig. I wanted to use two 12" bass drivers in one enclosure,but get them with different frequency response characteristics. One shifted to the high side ( up to 2khz ) and one dipping into the low side ( down to 30 hz ). The question is would this filter be possible with high power ( over 200 watts per driver )?

Chronus, this isn't really a design for a loudspeaker, more of a thought experiment as to how crossover elements harmonise!

An externally hosted image should be here but it was not working when we last tested it.

A PA speaker is a considerably different animal from a HiFi loudspeaker. 😀

It's all about efficiency and sound reinforcement from multiple drivers. My own experiments with PA stuff were pretty woeful. Firstly you tend to use efficient cardboard surrounds (rather than rubber) which are pretty ragged in themselves. We used to use a pair of different 8 ohm 12" Goodmans bass units in my College Disco cabinets. They were wired in parallel to make 4 ohms and one had a lot more top end than the other. Wiring them in series was plain poor.

I never got anything good out of them for fullrange use until I fitted 15" Tannoy Gold fullrange units. This has almost nothing to do with building a PA system for Bass guitar. I would think you need 2X 12" or 4X 12" in a stack with no crossover whatsoever. 🙂

 

[sreten]

system 7,
with regard to the second woofer arrangement. I am considering trying this my bass guitar rig. I wanted to use two 12" bass drivers in one enclosure,but get them with different frequency response characteristics. One shifted to the high side ( up to 2khz ) and one dipping into the low side ( down to 30 hz ). The question is would this filter be possible with high power ( over 200 watts per driver )?

Hi,

This can be made to work in some form electrically if you can wire the drivers
in series. It can also be made purely mechanically by choosing quite different
drivers with parameters and responses such that one does most of the
spadework at the low end and the other one dominates the top end.

rgds, sreten.

 

[sreten]

I have always considered the ones with resistors to be more musical, but
of course it raises damping issues with bass units (which are solvable...).

Hi,

A very vague statement, other that it applies to a lot of tweeter x/o's.
I don't know of any solution to ~ doubling a drivers Qts and / or the
inevitable 3dB loss in efficiency / 6dB loss in sensisitivity in the bass.

Two drivers in series, one with a parallel capacitor, has been done.
It doesn't implement baffle step like the parallel 0.5 way arrangement.
I've never seen it in a speaker with aspirations to quality though.

rgds, sreten.

 

[system7]

Hi,

A very vague statement, other that it applies to a lot of tweeter x/o's.
I don't know of any solution to ~ doubling a drivers Qts and / or the
inevitable 3dB loss in efficiency / 6dB loss in sensisitivity in the bass.

rgds, sreten.

GRRR...you just did it again, sreten. Most of that stuff was good, then you GO AND SPOIL IT AGAIN! 😀

An externally hosted image should be here but it was not working when we last tested it.

I'm not even going to tell you how you fix it for bass, but it can be done. 😎

@Chronus. Maybe that filter CAN be done. Remember Cz= Le /Re squared. Not sure it's gonna be ideal with PA speakers though. You're going to lose a LOT of efficiency and loudness for a possible improvement in frequency response.

 

[jsa_ind]

James TRexx I couldn't agree with you more Omnidirectional is the way to go! The depth, the imaging, the precision is too good to be true!🙂

Dave from Planet 10...you are so correct! My wiring was weird indeed

I have now rewired the loudspeakers to + AMP>+SP->+ISP->+RSP->+65SP-AMP Which I now presume is all firing in phase except for the rear speaker which is out of phase??? Could you please do a double check & advise, if I am correct or not?
Abbreviations:
AMP=Amplifier
SP= Front Speaker
ISP= Front Inverted Speaker
RSP= Rear Speaker that fires 180 degrees to front two speakers
65SP= Side Speaker that is 65 degrees to main speakers

For my room of 24 feet Width X 17 feet Length X 9 feet Height the Bass has increased substantially and the imagining even better! Thanks a million Sir!😀

 

[planet10]

I have now rewired the loudspeakers to + AMP>+SP->+ISP->+RSP->+65SP-AMP Which I now presume is all firing in phase except for the rear speaker which is out of phase???

Wired like that all the drivers are in phase.

dave

 

[Radugazon]

...and easy to pick out occasional effects where Jimi Hendrix would momentarily be out of phase during a pan... I used to hear more 'mistakes' in commercials where one side would be out of phase, but that seems more rare now. But yes, it IS 'trippy'. Just not necesarily accurate reproduction.

No worries, phase manipulations on some tracks ( of course not all ! ) are basic job in production when it's decided to put emphasis on a given sonic event. Almost every time you ear something out of the speakers, if your system and the reflection pattern of the room/layout somewhere allows it, you can be sure that the opposite channel is at least out of phase. With some mixing expertise, the sound source can even be perceived behind the listener ( the dog in Amused to death/Roger Waters ). With the modern computerized mixing, it's now very common practice in synthetic music.

Naturally, translating this in an audible effect is and is only accurate reproduction.

OTOH, implementing as the OP did some permanent kind of effect can be momentarily pleasant but is not HiFi...but this can be done in more subtle and efficient ways when some degree of decorellation is researched.. In some border cases also, out of phase wirings can be encountered as in a Bessel array.


Illustration of the mixing from a Q-Sound track. Without Q-Sound, it's fully panned to the left ( pic 1 ). With Q-Sound, ( pic 2 ) an out of phase synchrone signal appears on the other channel and the reproduction is globally more realistic while keeping the same source azimuth.