Took a stab at testing and modifying my BIC DV62si Bookshelf Speakers...

[motleypixel]

Hi folks,

Please just "tell it to me straight" on areas I could improve on the testing process I define in my video below. Please do keep in mind I really didn't want to remove these speakers and do a "formal" near field test. I tried to keep the before and after as close to apples-to-apples as possible.

I connected with user @Dave1027 and boy has he been helpful in this endeavor. So much so I shipped off my cross-overs from these speakers for him to upgrade.

Some areas I'm unsure:
- Should I have had my tone controls mid-way instead of all the way down? My reasoning here knowing that it will reduce the levels I simply increased the output to hit the target OK SPL levels in REW so in the end the levels were at the target 75db as required for the sweep w/o any bias on the frequency gain.
- Is the new insulation treatment too much? My thinking here is that I'm somewhat affecting the volume of the enclosure.
- I have high frequency hearing loss. My recent audiogram shows that at 1.5K I drop off into the moderate to moderately-severe hearing lose regions. I like cranking treble, would this explain why?
- I figure that most all of the peaks in the REW sweeps are due to room reflections right? So with that in mind, what's the general consensus of the before and after? I wish there was a way to programmatically negate the reflections somehow?
- Finally, I'm testing out some hearing aids now and boy what a difference. I can stand 10' on center in front of my system with them on and then toggle them off and the sound is night and day. With them off the system sounds extremely flat but on the open up from the mids and above...what a treat to listen to music like this now.

Again, please help me learn good practice testing routine with REW. Anything, even it it means spending more on a better calibrated microphone.

Thank you,
Roy

 

[faber12]

Hello,
I think that it is cool what you are doing to these. To answer your questions:
1. Yes, the tone controls probably should be set to middle position. There may even be a detent or tactile stop in that position. The knobs usually either cut or boost those frequencies, with the middle setting being flat. For measuring they should be set to flat, but for listening they should be adjusted to taste.

2. Fiberglass amount is fine. I would not worry about that.

3. Yes, HF loss would easily explain the tendency to crank treble.

4. Reflections do make a difference, but I am not sure the measurements mean anything without the tone controls set to flat.

 

[turnitup]

Depending on the amplifier/receiver’s age and condition, this could have a huge impact on playback (as large or potentially larger) than your speaker’s condition. As caps age, you will generally find that you need to increasingly ”crank up” the treble/mid/bass to compensate for this aging process. Don’t discount this in your overall evaluation…

 

[fredgarvin]

There used to be a guy that had a cottage industry in modifying the xovers for those. It seems that he used to post here or maybe it was ebay.

 

[faber12]

Ed Frias was his name I believe, but I have not found any recent information about his speaker modification activities.