Axiom Home Page Forums General Discussion Home Theater Twin Speaker Sets for A/V

For those of you that are building home theaters for audio & video, you may want to consider two sets of front speakers. One set for movies and another for music.

I was thinking that movies would benefit from speakers that are spaced further apart and mounted "high". Wall-mounts would be perfect for this application.

Music benefits from speakers that are toed in and closer together. Floor-standing or bookshelf speakers are best suited for this.

The different speakers could be activated by the A/B switch on the receiver. Does anyone have a set-up like this?

If we all say no, will you try it out?

Tex, I looked, but I don't have any pics from a set-up I had years ago. I had a small 10x10 room that I jammed two systems into. Axiom M40s were my two channel speakers hooked up to an integrated tube amp. On top of the M40s I placed two Monitor Audio GR10s and used a rubber stopper underneath to tilt them forward. The GR10s were part of an HT system with a matching center and some Energy C-2s as surrounds. Also in the room was a 34" CRT TV and a Hsu VTF3 MkII.

Cramped? Yes, but it still worked pretty good. I just recently moved and had to dismantle two separate systems--stereo and HT--and combine them into one. It's funny you brought this subject up because I actually thought about trying to tuck extra speakers up front to run two systems. Sadly, my sense of decor took over. I think I've grown accustomed to the uncluttered look. I'll have to take some new pics.

I know that as Axiom board members you have high integrity so you will all do the right thing and speak the truth .

I suppose I could try it out. I still have my old Sonys that I used as rears along with their stands. I could set them up a couple of feet away from each M80 to see how they sound with movies. I just can't mount them very high.

Charles,

So I have tried it and here are the results. BTW, the only measurement tools used were my sound meter and my ears. And my ears of course don't count (that was for you Wid and BrotherBob).

Configuration

I have two sets of speaker cables at the front wall. One for my M80s (A) and another set (B) for crazy tests like the one that follows . So it was pretty straight forward for me to A/B and also to A&B. With this test, I was simply trying to see how soundstage was affected with various configurations. I took measurements to see how SPL changed with the Sonys vs. the M80s so that I could adjust the left and right channel levels. I found that the Sonys needed a 4dB boost to achieve the same SPL as the M80s. I also changed the cut-off frequency from 80Hz for the M80s to 100Hz for the Sonys.

I tried two different elevation configurations: 1.the black stands with the tin cans and 2. stands, tin cans and the plastic boxes. Configuration 2 raised the Sonys to the same height as my QS8s. For each configuration, I tried toeing in so that the tweeter paths were crossing anywhere slightly ahead of me to slightly behind me and also pointing the speakers straight ahead as recommended by DTS, Dolby, etc.

BTW, the Sonys are made of plastic, not filled with anything at all and use three paper drivers. They are ported on the very bottom.



Source Material

For source material, I listened to Diana Krall: Love Scenes and Oscar Peterson:We Get Requests in stereo, PLIIx: Music and Neo6: Music, Alan Parsons:On Air in DTS EX and King Kong in DD: EX.

Results

There really was no difference between the two elevation configurations so I ended up doing all of the listening in config 2. And with the speakers pointed straight ahead, I absolutely disliked what I heard in my initial listening tests. So all of my serious listening was conducted with the speakers toed in.

First of all, I have to admit that I am very, very surprised by what I heard. I expected movies to sound wider and more expansive with the Sonys mounted wide apart. Instead, what I heard was a very disjointed sound stage. It simply wasn't cohesive. There is a scene in King Kong where he is being shot at and then he jumps up and knocks down the plane. With the Sonys, the shooting sounds too far removed from the action on the screen.

I did notice however that the image transition from the sides to the front was a lot "smoother". Track 11 of Alan Parsons is a great track to gauge this. Towards the end of this track, the vocals shift slowly from the right surround to the front right speaker. This transition doesn't take place smoothly with my M80s probably due to their location. With the Sonys, the transition was very smooth. I didn't have to listen too hard to hear this. However, most source material does not contain transitions like this one so this is a very insignificant benefit.

I expected music in stereo to not image well and here I was not surprised. The Sonys had a very good centre image but it was very (too) tight (probably due to a lack of good midrange?). The soundstage with the Sonys was terrible consisting of a centre, right and left images with nothing in between or outside the speaker boundaries. It very much reminded me of my Bose 601s except the midrange on the Boses was much better.

I expected PLIIx and Neo6 to sound more expansive with the Sonys. It did not and my experience was very similar as with stereo mode.

Now here is the big surprise. When I did A&B, I absolutely loved the fullness of the sound. Imaging and soundstage was just as good as with only the M80s. The big difference was the centre image. It was now taller and a bit wider. It sounded like Diana Krall was no longer standing on my floor but rather on a stage. Initially, I liked it. Then the more I listened between A and A&B, the more I didn't like the quality of the sound. I called my wife down and asked her to listen between A, B and A&B. She immediately discounted B but could not decide between A and A&B. So she listened some more and finally picked A because it sounded more "velvety". She said it was like the difference between a small dose of Bernard Callebaut chocolate vs. a large dose of Caramilk. King Kong sounded more full with A&B and my final conclusion regarding movies and "velvety texture" was that it really doesn't matter.

Final Conclusions

Wall-mounted speakers, whether they are toed in or face straight out, will not enhance your movie experience and will destroy your musical experience. However, a good set of wall-mounts when mated with good floor-standers, may actually enhance movies and music. I am seriously entertaining now a set of M3s mounted on my front wall and toed in. I'd be willing to bet that with the M3s+M80s, I can achieve the velvety texture and an improved centre image.

Notes

My Denon had no problem at all running both sets of speakers simultaneously. The specs on the Denon say that the load should be restricted to no less than 8 Ohms when A&B are on but I didn't hear (or see, smell ) any ill effects even at ear splitting volumes. The combined impedance of the M80s and the Sonys are at least 2.7 Ohms. The more I work with my cheap Denon, the more I praise the engineers that designed it.

Now I also have to try what Sean is suggesting (putting the Sonys on top of the M80s).

Does any know how I can make a living doing this?

Could you possibly, I don't know, attribute the poor results from high and wide speakers to their quality? I'd be interested in seeing the results with the speakers swapped.

Well, that ain't gonna happen .

But, like I said, I am planning on positioning the Sonys on top of the M80s to see what difference it may make. My experience tells me that they were too far apart for good imaging. I don't think putting M3s up there would make a big difference in that regard. I know that if I move my M80s further apart, soundstage and imaging are grossly affected.

Tex, the sound actually improved on my Monitor Audio GR10s when I placed them on top of my M40s. To clarify, I believe the acoustic relationship of the speakers to the room changed. I used the rubber stoppers that came with the M40s under the back of the GR10s to angle them down to my ears. This angled the port from firing directly toward the wall and really cut down the bass boom. I don't exactly remember how far from the wall the speakers were--too many years ago.

This is awesome. What else can we get Mojo to try out for us?

What your looking for, Ive already found.

Stereo! You would be surprised how good movies sound in plain ole' stereo. To be honest with you, I enjoy movies just as much on my 2 channel setup as i do with the 7.1 dedicated theater. Of course, The LFE is a bit better with the EP600, and the screen is over twice as big but with stereo the center image doesnt have to blend in with anything, its just there. Yeah, There's only one good seat in the 2 channel theater. But sharing is overrated.