Proac Rake angle?

You have to experiment to find out what works best. I would start by moving your head up and down and see what happens.

I agree with sfall. I would keep them level and get a different chair if you determine the height makes a difference requiring remedy.

In my limited experience, although I've been impressed with some speakers that have utilized rather noticeable rake angles, I've found no improvement by changing that on my own speakers. But I have found most speakers sound best to me a bit higher up than is commonly recommended. (I'm just under 6')

As the M-T-M design of the D48R may limit the vertical flexibility of speaker/seat placement even more, you may find it worthwhile to try it out.  (The advantage being less overall room reflections, I believe.)

I would contact Pro Ac - they will let you know which practice is best

Tilting them can upset this alignment - depending on the speaker deign. They could end up sounding much worse in other areas

Do you hear a difference if you align your ears with the tweeter?
- Try standing and then sitting and noting the difference in image.

If you do hear a difference - I would suspect reflections from the ceiling or side walls are causing the change

To be able to provide better feedback...
- how high is the ceiling?
- How far are you from the speakers?
- How far are they apart?
- How far are the center of the drivers from the
>>> wall behind them?
>>> side walls?
- Is the floor between the speakers and yourself and the speakers carpeted?
- Do you have the ribbon or dome tweeter

I believe the dispersion patterns from the drivers should compensate for a couple of inches discrepancy on listening height. ProAc's have a pretty good reputation for being easy to place (within reason). 

In practice, I've never heard any difference whether seated or standing with the Pro Ac models I've listened too, but they did not have two bass drivers

I've tried tilting with my own Gershman Acoustics speakers, but I found they were better when virtical.

The other hing I've found impacts imaging is the furniture in the room - e.g. I had a 7ft book case in a corner behind the listening position. There were some serious reflections happening the top of the book case and the ceiling, which caused smearing - A piece of 1" foam on top of that book case cleared that up and improved the imaging.

Speaker placement and furniture are critical when trying to achieve the best image.

Regards - Steve
.   

Thanks everyone for your responses. Williewonka, I emailed proac and Stewart replied and advised not to tilt, and  to get a more ideal seat.  Will do.  On a side note, I will say that these have truly started to sound magical.  FINALLY.  I was worried about them to be quite honest, and thought I had made a mistake with them.  They sound so much better than they did upon first hooking hem up.   For the last 3 days, they've been playing Mahler, so that probably loosened them up right there. It is true, they need 500 hours before you can judge them.  They almost sounded defective at first!  What a difference.  These really do cast a spell on the listener. I'm simply amazed.  With 550 watts Mahler has never sounded so real.  The dynamics and just shear prowess of these speakers is astonishing.  

Audiolover718 - you might find they take a dive in performance around 30-60 hours, but by 100 they will start to sound very good.

From 100-500 hours the improvements will be more gradual.

You don't have to play them "at volume" to burn them in - you can leave them running at very low volume. This will burn-in the crossover circuitry and the voice coils. 

What speaker cables are you using?

Cheers

Listening to these amazing speakers as I type. I've got about 500 hours on them and they are a spectacularly precise, transparent and wholly satisfying speakers.

I tried both biwire mogami 3104 and synergistic research atmosphere level 1 single run.   Honestly, once broken in, I prefer the synergistic to the biwire mogami.  The mogami sounds slightly richer, but I lose transparency, speed and focus when compared to the synergistic.   The synergistic are a whole different ball game.  The synergistic cables create ghosts in the room. The Maggie's hinted at this. The proacs are supernatural in their presentation. They are so transparent, that the mandatory warmup on my preamp is so much more noticeable.   It  doesn't get truly "hallucinogenic" sounding until about 30-45 minutes, but it when you reach that time, it's like an aural thrill.   

Now honestly, I don't know if it's that the speakers don't respond well to biwire with my equipment, which would go against conventional wisdom around here with proac, or that the mogami is just that much worse of a cable than the Synergistic.  But I cannot get the magic focus and coherency with the mogami biwired as I do with the synergistic single run. But at the end of the day, we all must trust our ears, and do what we feel sounds better to US.   If it sounds good to YOU, then it sounds good. Many people swear by biwiring the proacs.   Didn't work out for me, with my given cables.  Many people will also say that higher end single in will out do a mediocre biwire.   

Its amazing that an entry level high end pre like the LS -17 can sound so amazing, but with the dac 8, ds450, and the D48r, it's actually quite stunning.  I can't imagine how bonkers  a ref 5se would sound like to replace it.  Best part?  The sound at low volumes, completely satisfying with full projected images at proper size.  👏 

Try replacing the stock jumper bars with a jumper made from the Synergistic cable you are using, if you have not already done that. Replacing the bar with a jumper made from the same cable made a positive difference in my system.

+1 for Jperry's comment above - jumper bars are probably the worst thing to use - I always use speaker wire the same as the speaker cables.

If you have store bought cables then get some quality wire from a company like Van den Hul or DH Labs. They both use great quality copper

Regards...

Agree with Jperry as well. I replaced the jumper bars on my D-30R
with Clear Day Cables jumpers and the difference was noticeable.
Probably didn't hurt that I'm using Clear Day cables too.

Replaced replaced the jumper bars since day one.  My shop gave me 4 small scraps of proac cable to use.  Even from day one it was noticeable.  :-)