Which speaker to replace Dunlavy SC-V?

one of the things i,ve noticed when i had my Dunlavy,s is that as stated by John Dunlavy in the owners manual you should place them across your long wall in your room with more distance in between them than distance between the speaker and the sweet spot (somewhere between a 60 to 90 degree angle, a lot of toe in). This way they sound absolutly fantastic

This is necessary for speakers that have narrow dispersion like the DAL V's...ideal for a precise image with a minimum of reflected energy. Some call this the "equilateral triangle" setup. However, it will only give you a small sweetspot for critical listening and therefore it is not well suited to HT or situations with two or three listeners.

"you should place them across your long wall in your room with more distance in between them than distance between the speaker and the sweet spot".

Two comments on this one.

1) This is pretty much how ANY large multi-driver speaker works best. This is true for everything short of a multi-directional design and applies to both hi-fi and HT installations.

To clarify this, one needs to sit JUST BARELY inside the "listening triangle", not at the apex of the "listening triangle" as most would say. How far inside one has to come inside the triangle has to do with the individual speaker design and how much toe-in is being used. Personally, i prefer to get the speakers as far apart as possible without having the center image collapse and use as little toe-in as is necessary.

2) The Dunlavy's are NOT a "narrow dispersion" design. The MTM driver layout produces a very wide horizontal dispersion pattern with very limited vertical dispersion. By spreading the speaker further apart, which therefore seperates your left and right channel imaging, you get a wider soundstage. Due to the wide horizontal dispersion, the center image is still retained.

The more toe-in that you use, the stronger the center image and the narrower the the "spray" outside the edge of the speakers. The less toe-in that you use, especially when spreading the speakers way out, the more diffuse the center image with a wider overall presentation.

The biggest problem with the bigger Dunlavy's in most rooms is that the bass is inconsistent. This has to do with the room loading effect ( or lack of it ) on the top woofer. Tom aka Theaudiotweak and i discussed how to take care of this quite some time ago.

The other problem with Dunlavy's is the fact that they are "vertically challenged" in terms of high frequency dispersion, which i previously alluded to. As such, you have to find a seat that places your ears at the right height, otherwise the treble response is compromised. This is true of all other designs using an MTM array though, so it is not unique to Dunlavy speakers. Sean
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Sean, as you probably know I am in complete agreement with you on just about everything stated above. The one area, I'm not so sure about is the issue re: Dunlavy's and inconsistent bass. I have noticed this on occasion, but not always. I think uneven ceilings had more to do with that, in those cases that it did. I wonder if the Dunlavy's might actually produce better bass due to their design. I can't help wondering if by having the top woofers reflecting from different distances against different textures and structures than the bottom woofers, spreads out the effect of boundry lobing, actually evening things out?
I also wonder if John Dunlavy was able to keep his company going and he actually produced the planned digitaly amped, digitaly crossed-over speakers with their "FLAT" baffles if the vertical issue would have been resolved?

Unsound: Obviously, non-symmetrical loading of the woofers "can" create a flatter overall in-room response. Acoustic Research put this to use in their 9 and 90 designs, showing various frequency response results in the manual. Unfortunately, such is typically not the case with the type of design that Dunlavy utilized. Whereas the AR ( and similar designs ) always have some type of loading on the woofers due to proximity to the floor, the Dunlavy's might have the top woofer further from the ceiling than it is from the floor!!!

With that in mind, I have yet to find someone that doesn't think that the Dunlavy's are improved when using some type of baffle extension / "sounding board" near the top woofer. One can even fine tune the amount of reinforcement / frequency of cancellation by experimenting with the size / angle / location of the baffle extension. Due to their low Q "over-damped" design, the lack of room reinforcement can REALLY make the Dunlavy's seem like they are lacking in low frequency output. Making use of the aforementioned baffle extension can not only improve bass extension, but also apparent bass weight. When you can increase both extension and output without negatively affecting transient characteristics, it's typically a good thing.

The baffle extension can either be mounted from the ceiling down or from the top of the speaker up. Obviously, mounting it to the top of the speaker makes the design more versatile, as you can now position the speaker without having to go through the hassle of re-positioning the ceiling mounted baffle extension. This might not seem important as one would think that they could position the speaker optimally and then mount the extension to the ceiling, but when you install the extension, it will also alter the room loading characteristics / tonal balance. In turn, this may change optimum placement characteristics slightly.

Baffle extensions are a "trick" that can also be put to great use with small stand mounted monitors to increase low frequency output. Some people refer to this type of baffle extension as a "baffle beard" when used on stand mounts, as it can resemble a long hanging beard that is pitched slightly forward. Sean
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Sean,

The DAL V's might NOT be a narrow dispersion "design" but they do throw out a narrow dispersion pattern, this is well known being quite senstive to adjustments of toe in. As I stated, this is not ideal for HT where a broader dispersion pattern and a larger sweetspot is more desirable. They are still undeniably a fantastic speaker and I have never heard anyone call their bass response inconsistent.