A comparison between my Tannoy (Edinburgh) Monitor Gold 12 and Celestion Ditton 66

[Fatmarley]

How far out would I have to go?

It depends on the distance to the side wall. The closer to the side wall, the less you have to pull the speaker out to achieve a flat response.

Looking at my sims and your measurements, it looks like the further from the walls, the less output around the 80hz to 100hz area. Do they sound a bit less punchy or do deep male vocals sound a bit lightweight with the speakers further out into the room? How do they sound overall?

 

[ToTo Man]

It depends on the distance to the side wall. The closer to the side wall, the less you have to pull the speaker out to achieve a flat response.

Looking at my sims and your measurements, it looks like the further from the walls, the less output around the 80hz to 100hz area. Do they sound a bit less punchy or do deep male vocals sound a bit lightweight with the speakers further out into the room? How do they sound overall?

I've grown accustomed to the sound of the 66s being placed in front of the Edinburghs, which results in weaker bass from 60Hz to 100Hz as you correctly noted. This is the first time I've been able to position them closer the front wall. They do sound muddier and more chesty now, but part of this could be me being used to them sounding thinner than normal at these frequencies.

They definitely sound more 'robust' when placed closer to the wall, but being a bit further away from the listening position has also very slightly reduced the amount of energy I'm hearing in the upper mids / lower treble which, together with the fuller bottom end, is making them sound a bit more laid back and less exciting.

PS - My dad's going to retrieve a GIK Monster Bass trap from the attic tomorrow, so I can hear what effect placing it behind the speaker has.

 

[ToTo Man]

Placing a 48"x24"x6.5" GIK Monster bass trap behind a Ditton didn't produce the result I'd hoped for. It narrowed the 135Hz null a little but actually made the 75Hz null deeper (measurement here). Whether or not this would be audible is up for debate.

The bass trap has a beneficial effect on the 75Hz null when placed behind my listening seat (half way between the back of my chair and the rear wall), and this is indeed where I normally place it (measurement here). However, since removing the trap from behind my chair my room looks a lot bigger and more light pours in from the window, so I might give it the boot!

Moving the speaker closer to the side wall improves the low bass response, but it pushes the 135Hz null higher in frequency and creates a wide dip in the upper-bass/lower-midrange (measurements here). Note these measurements were taken with the cabinet flat on the floor, parallel to the front wall and approx 55cm from the front wall (measured to front lip of cab).

Here is the response of the speaker placed as close to the side wall (48cm to cab side) and as close to the front wall as is practical, toed-in so that the tweeter is aiming at the listening seat, and tilted back for the best treble response (measurement here). This puts the speakers 2.85m apart (centre to centre) and a diagonal distance of 2.65m from the listening seat, i.e. the setup is slightly wider than an equilateral triangle.

The combination of the speakers being further apart and the broad dip in the upper bass / lower midrange pushes vocals further back into the soundstage and makes them sound lighter (i.e. less weighty). I also notice that the phantom centre image isn't as strong with the speakers placed this far apart, it's still there but isn't as obvious on some recordings as it is on others. I'm not sure whether I prefer the tonality and imaging of the Dittons in this wide and far arrangement or in the original Tannoy position, or in a position somewhere between the two.

This is the averaged left & right speaker response of the two positions:

And finally the averaged left & right speaker response of the new wide position after applying EQ mainly to tame the bass boom: