Great Imaging Speakers Working against a wall?


Hey all,

The audio upgrade bug seems to be biting again -

Have an average+ sounding system that I'm desperate to do something with, on a tight budget.
Audio Alchemy DDS Pro Transp.
EAD 7000 III Dac,
Conrad Johnson CAV 50 Integrated
QLN Signature Splitfield Monitors on Target stands.

I'm really wanting a system with warm midrange and great soundstage - I'll never forget hearing a pair of KEF 103's about 10 years ago that threw a soundstage that seemed to start about 2 blocks away!

My QLN's image ok, but nothing special really. Mids are ok with the warmth from the CJ, but they lack soundstage depth/width and pinpoint imaging. (QLN's are a quality speaker from Sweden with an external cross-over unit, bi-wired and sitting on lead-shot filled Target R3's, use Vibrapods, 3 per side, spikes into floor, speakers sold for about $3000 when new)

My room is a problem, 35ft by 12 ft and the only setup position (without divorce) is with the speakers toward one end of the room against the long wall, left speaker about 4 feet away from side wall, 10 feet between speakers, 40" from rear wall, toe'd in to listening seat which is against the back wall. I've messed with toe-in, distance from from the walls etc, but I can't do anything that makes any significant difference to their imaging/soundstage ability.

So, I'm thinking maybe the answer is to find speakers that work best hard against the wall, like the old Kef's or Linn Sara's and Kan's used to do. This would put more space between them and the listening seat, and might improve things.

I'd buy used and have about a $1000 budget.

I would really appreciate any input.

Or maybe I could put the money into another part of the system, but I think the speakers are too constrained by the room and position options for them ever to give me the sound I'm looking for.

Any suggestions?

Thanks

Rooze

128x128rooze
Deaden the walls behind the speakers and the listening position. Relocate any "stuff" you might have between the speakers.
Some speakers will image quite well up against a wall. That is, IF they are designed for such a situation and you have NOTHING in between them. This means no racks, tv's, etc... that protrude beyond or close to the front plane of the speaker.

In order to achieve this, the speakers would normally have to have a very focused radiation pattern. As Duke mentions, baffle shape and dimensions will also come into play and the use of some type of "acoustic blanket" or sound damping material ( felt, foam, etc.. ) on the baffle also helps. In effect, the "acoustic blanket" helps minimize stray radiation and reflections, making the wall behind them less "attached" to the baffle acoustically.

Other than imaging and soundstage, Duke brings up another very valid point. That is, he talked about woofer loading / room reinforcement when a speaker is placed near a room boundary. Placing a woofer closer to the floor, near a corner, up against a back wall, etc... will add bass reinforcement. Obviously, this could skew the tonal balance of a speaker if it were not designed for such placement. If the speakers are quite lean sounding though, one can take advantage of the situation to help fill out the bottom end. If the speakers already had reasonable bass response, you could easily end up with too much of a good thing. To top it off, the bass would probably not only be more apparent, but also of poorer quality in terms of definition.

If a speaker already has some form of woofer loading to it, this would make it slightly less susceptible to reinforcement from the back wall. That is part of the reason why the Snell's that Duke mentions could work well in such a situation. Such designs are still susceptible to such a situation, but not as severely as a "standard" design.

Some speakers were even designed for such a situation. The older AR 9's and 90's took room placement into great account when being designed and were recommended for placement up against the wall. These speakers were VERY ground-breaking in many areas and that is why you see many of their design innovations popping up in more current speakers. There are reasons why these and other speakers seem to have "odd" driver placement i.e. having the woofers mounted near the floor and on the sides of the cabinet, etc... Unlike many speakers, these were designed to work with the room taken into consideration and not just tested anechoically. This is discussed to a very great extent in the owners manual for these speakers, which just so happens to be 50 pages thick !!! AR provided various graphs and a lot of technical information for different speaker locations in terms of room boundary reinforcement. They also showed how these speakers would work in comparison to a "standard" speaker put into the same situation. While one could take this as a marketing ploy, one's ears and experience could verify much of the information that they presented in these graphs.

The other speakers that instantly came to mind for such a situation were the old Allison's. Roy Allison believed in using the room and not fighting it. As such, his designs are a little unconventional but can be made to work where other designs fall short.

Since you mentioned Kef's, there was an older design that might work well for you that they made. I want to say it was the 105, but can't remember exactly. This had an LED that one could see if you were sitting directly on axis with the tweeters. They were of a very focused field design, which should give you what you want for your specific situation. Whether or not you like the individual characteristics of this speaker or others like it remains to be seen. Sean
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Sean, fine post, with kudos to Roy Allison, of course....
But have ever REALLY heard flush-mounts that have stage depth BEHIND the speakerplane?
Two possibilities come to mind. Perhaps by deadening the reflections off your left wall you could effect better symmetry of image. Secondly, try to follow Harry's rule of thirds by moving your chair away from the back wall. You can push it back between listening sessions so as not to upset wifey's symmetry. This plan may require you to experiment with the distance beween your speakers.
And remind your wife that you bought the house to live in..........not to look at.
Thanks all for some great ideas!

With only 12' room width, and the speakers 40" from the front wall, there is only scope to pull the listening seat a foot, maybe 18" at the most, from the back wall. I've tried this and frankly, being within 5/6 feet of the speakers which are 10' apart doesn't really give the sound chance to 'integrate' (looking for a better word here).

Moving the speakers closer together, and me closer to the speakers, gives a little more stage depth, but closes down the stage width - which is not really desirable.

I note Subaruguru's comments about never getting real stage depth with speakers against a wall, but believe me, I've heard remarkable stage depth from a pair of Kef 103's, driven by an old bryson amp and a Sony CD player!!

The speakers were flush to the front wall and seemed to stage from level with the front (little or no forward projection) to some 15 or 20 feet behind the speaker - on a non-audiophile recording to boot!

This experience was some 10 years ago, and perhaps the stage depth has increased a little with memory loss, but it was truly excellent!

So I guess I'm asking another question...do you think the source and amp that I have could create the stage depth/width and imaging with perhaps a pair of Audio Physic Sparks - listening in the nearfield, with 40" max between the front wall? - Audio Physic recommend the listening seat hard against the back wall on their site....any better ideas.

On the ever developing 'wife front' - when she met me I lived in an apartment with a 18' X 38' living room, occupied by a love seat, tv (sitting on the rug), a pair of Apogee Caliper Signatures half way down the room, Linn LP 12 and a Krell 300i.....the only other furniture in the whole apartment was the bed!
So....I was good enough for her then, what's changed?

I suggested some form of counselling, but she actually wanted me to go with her, can you believe it?

Rooze