@rolee910 I have been demo'd the B&W 804 D4 Diamond Speakers in a system where a selection of Digital Sources were used with Devialet 1000 Amp's. After a few tweaks for the Speakers (undoing the Speaker Owners choices) that can be achieved using the settings option on Devialet Amp's. l wear it on my sleeve that the 804 D4 Diamond Speakers made a very very good impression.
Additionally, a method that can be used to Tune Ported Speakers, which experiences have proved will Tone Down the Upper Most Frequencies and is also a method I have used myself when using Cabinet Speakers with Ports. Is where I have made my own adjustments to the Speakers Port, by reducing the Port Diameter and Increasing the Port Length.
If translation is an issue, the following will need to be carefully considered, even though the practice is quite simple and will not cause any issues for the system. To experiment with such a methodology will not cost too much money, and the required fix may be discovered?
To get the idea of how a Extension of the Speaker Port can effect the sound, a Plastic Tube with an OD of 1mm less diameter than that of the Speaker Ports ID. With the Plastic Tubes Wall being approx' 3mm, can be used in conjunction with the Speaker Port. A wrap of Tape on the inserted Plastic Tube, to take any slack can be added if need be. Think Trombone as the Tuning Method.
To substantially change the ID of the Speaker Port, think about using different thickness Liners to be used within the Speakers Port, when inserted are able to change the Port Diameter. These can be made from a medium soft foam, that can support itself when inserted. Different Foam Thickness will create a different Port Diameter. I have used Pipe Lagging for this purpose?
I have also plugged the Port, but did not get the wanted effect from this method, it should not be overlooked as a option to Tune a Speaker Port.
If a Speaker Port Tuning is discovered that suits the room the Speaker is set up in for the better. The same Port Liner can be slid forward in 20mm increments to tweak the Port Length. If extending the Port Length adds to the impression being made from the ports tuning, find the ideal extension length and make a new Port Liner that has the Speakers Port Length and Additional Length combined to be inserted within the Speakers Port.
The outcome in the Rooms I have carried this port tuning out on, has been discovered as beneficial across the entirety of the frequency range.
A tighter/leaner Bass Note + Improved Bass Roll Off + Improved Bass Note Decay. Upper Most Frequencies have become less prominent + improved in their cohesive integration into the mid to upper frequencies.
As a side, my Floor Standing 3 Way Cabinet Speaker are also of such a design due to the want to have flexibility in room tuning. The Speakers Construction methodology selected allows for the option to change the Cabinets Internal Volume by approx' 30 Litres per Speaker, ( 45 Litres - 75 Litres per Speaker Cabinet) .
As I am a long-term ESL Speaker user as the main Speaker of choice for the home system. I have referred to the Cabinet Speakers after having undergone Port Tuning as becoming more ESL like, producing a Upper Most Frequency presentation, I wish the ESL Speaker could mimic.