Excessive Midrange Energy?


Greetings,

I wasn't sure whether to post this on the digital forum or not, but I'll give it a whirl here.

Earlier this year, I completed a custom loudspeaker project using the Great Plains (Altec) 604 driver. Ever since building the speakers, I have been battling excessive midrange energy. I'm on my second set of XO's, and have a third option in the works.

I'm powering the system with a new Cary SLI-80, and have tried both modes of operation (triode and ultralinear). I think I prefer the sound of the triode mode, but it does nothing to tame the midrange energy.

My source is a 15+ year old Rotel RCD-965BX. Now, let me start by saying I'm not a big believer in moon rocks and snake oil, but I do wonder if the CD player could possibly be contributing to this issue.

I realize that capacitors and other electrical components age, and I was amazed at how my Sumo amplifier changed in sound as it got upwards of 10 years old.

Is it possible that the CD player could be causing, or adding to the excessive midrange energy, or is digital, well, digital? I just want to make sure I'm not barking up the wrong tree before I go borrowing CD players and such.

Thanks a bunch for any input!
seadweller
Frankly, I'd suspect the speaker since its contribution to the frequency response exceeds that of other components.

Kal
The cd player is very unlikely to be the culprit. If you have a spectral balance problem such as recessed bass or treble range, it will make the mids seem prominent. Do you have a db meter and a test cd? The overall frequency response you measure should give you a better clue to as to where the problem lies.
Let's see: The problem arose with the implementation of these speakers. Did anything else change?

Kal
Thanks for the input. I strongly suspected the CD player was not the issue. Both the speakers and Cary SLI-80 are new to the system.

I originally powered the speakers with a Parasound Halo SS amplifier and Sonic Frontiers SFL-1 Pre-amp, but the desire for change got the best of me, and I decided to try tubes for the second time in my 30+ years in this hobby. The speakers also require an amp with a higher output impedance than the typical SS amp, and the tube amplifier did fill in the bass region quite nicely.

I have an L-Pad installed on the XO, but dialing it down takes the life out of the speaker. Is there such a place that you can take a pair of speakers and have them measured, in an anechoic chamber for example, and determine a crossover designe from these measurements?

I have so much time, money and energy in the speakers now, that at this point, I just don't want to give up on them. I feel like I'm one last grasp away from audio nirvana, but it's slippery indeed! 8)