Can "Dark"Sounding Speakers Be "Brightened"UP???

@freediver Try the Benchmark stack on it, AHB2 amp | LA4 preamp | DAC3B dac. You can always try this on a home trial or take a chance and buy used.

With warm speakers this stack would open up the sound. Doesn't the Decco have a tube in it. Warm speakers with a tube is not my type of system.

A cheaper option is a Class D like the PeachTree GAN400. I am putting my up for sale on USAM.

Put a streamer into the path instead of going direct via USB from the laptop. Not so much for your issue but to improve everything in the sound.

I have not heard the Decco but owned the PeachTree Nova 150. That is terrible compared to the new Peachtree gear such as the GAN400 and better yet, the GAN1 (but should modded it by tweakaudio). I replaced $15K of gear wit the $1200 GAN1 + $600 mods. However, that unit can ONLY stream via SPDIF, no analogue sources allowed. I used ROON to both stream to that and control volume. I replaced my Benchmark stack with the GAN1 since it was similar for lower cost, though eventually the lack of analogue inputs made me sideline the GAN1 only for headphones.

Just a thought but can you make the cabinet "bigger"? Maybe take out some of the stuffing?

I once made a speaker with a cabinet that was too big (like 2x too big) and the sound was bright. Filling it up with blocks of wood, the sound became darker. Actually too dark now, so I am taking some blocks back out.

@deep_333 well, I just did it: I replaced my previous speaker cables (silver plated copper + teflon) with some Duelund DCA cable, and it has shifted the tonality of the system, towards a darker, more laidback presentation. Just what I was hoping it would do.

It can be done the other way around too.

I vastly prefer to fine tune my system using cables than insert another active stage creating phase shifts / distortion.

But, you do you!

@freediver 

What you are describing is an amplitude problem, frequency response. He is using a computer and there are EQ plug ins that can be used to correct this. The smartest way to do this is to get a USB microphone with an amplitude program and measure the response of the speakers in his room. Then you adjust the EQ to get as flat as possible from 20 Hz to 20 kHz. Flat is always the best starting point. Next is to find the target curve that he likes best. The curve that most of us prefer will have the high frequencies rolled off at about 3 dB/octave from 2 kHz. 20 kHz will be about 9 to 12 dB down. Flat is usually too bright. Next will be a bass boost at 3 dB/oct from about 150 Hz down so the bass is up about 9 dB at 20 Hz. The only way your friend will get to know what he prefers is to play around with it and listen to different curves. 

I am sort of amazed that no one other than Geared 4me has suggested listening angle could be the cause. The FIRST STEP in any speaker set up is being sure you are sitting within the speaker/tweeter "dispersion pattern". For example, if you are sitting above the tweeter, you may be out of the pattern won’t be hearing it correctly- usually much less top end. If your stands are too short, or your floor standers are too low compared to your couch, or your speakers get very narrow on vertical dispersion and you are slightly out of that pattern, your speakers will sound dark every time. Buying cables to make it brighter is fixing problem you may not have and just gets you further away from the real problem.

Look at your speaker’s vertical dispersion, which is typically 10-15 degrees in "height". This means that the speaker only sounds correct within this 10-15 degree area of vertical dispersion. A big generality, but is usually about right, is a tweeter typically shoots straight out on the upper angle (parallel to the floor) and the lower angle points down 10 to 15 degrees. Imagine your tweeter as a flashlight with a 15 degree pattern of light- its the same as that.  This means you have to be within this area to hear it correctly as designed. So this is why we say your ear should line up with the tweeter or the speaker should be just slightly above your ear.

If you listen above this dispersion area, the tweeter output WILL be very low (by design) and the highs will appear to bad, low or even non existent. You can check what you situation is by just lowering yourself to be within that vertical dispersion angle and see if it gets better. If changing your height relative to the speaker makes it sound better, gives you more high end, then being at the wrong angle to the speaker is your entire problem. If it doesn’t get better with vertical changes in listening position, you have a different problem.

You can repeat this process with the horizontal plane as well, sit directly on center of one speaker at a time (turn off the other speaker so you can concentrate) L or R and then move slowly off that axis and see how the high end changes, and believe me-it does. Many speakers have poor vertical and or poor horizontal dispersion and require you be seated directly "on axis" (meaning pointed straight at your ears both vertically and horizontally) to hear it correctly. Sometimes the correct area is so small that just a tiny move of your head changes the speaker's sound drastically.  This on axis listening position is what is called the "sweet spot" and can be small or large depending on many factors, sometimes having nothing to do with the speaker itself.  It could also be your room and how reflective it is.

There are speakers that are better off axis and some that are terrible off axis. This "good off axis" is one of the features of a "better" loudspeaker that might be unnoticed on your first demo.  

Brad