My New Magnepan 1.7i's sound dull and lifeless on the top end...why?


First time Magnepan owner - 5  days old 100+ burn-in hours on them
Associated Equipment:
-Denafrips Terminator Plus
-Holo Audio May KTE version
-Pass Labs X22 Pre-amp
-PrimaLuna EVO 400 Pre-amp
-Pass Labs XA100.8 Monos
-PrimaLuna EVO 400 Monos
-AntiCables interconnects and speaker cables
-Stock tweeter attenuator jumper replaced with AntiCables level 5 spade jumpers on the 1.7i's

My spectrum analyzer indicates both speakers highs are falling off beginning at 1.25K and are 9db down from 2.5K on
Been playing around with speaker placement and room treatments for 2 days now without any remediation. What am I missing? Suggestions appreciated.
128x128nayls02

kingdeezie
46 posts
07-28-2021 6:05pm
I would think there is a problem with the speakers. 9 DB down in the highs? If the LRS sounds good on the same equipment in the same room, something wrong with the 1.7s.

Agreed
audiokinesis2,592 posts07-28-2021 8:27pmGetting good measurements of large dipole loudspeakers is not trivial.

My point being, it is extremely unlikely that casual non-gated in-room measurements made with a spectrum analyzer are "accurate" when there is major inconsistency between far more sophisticated, industry-standard measurement techniques. This is a situation where I would say, trust your ears far more than you trust your measurements.

Duke

The ears are telling me the highs are significantly truncated, and the analyzer confirms what I'm hearing.
kingbarbuda289 posts07-28-2021 8:45pmI have a pair of 1.7is. I recommend until you are very familiar with the Maggies and sort this issue out, that you run them only on solid state equipment. I have not looked up the specs on those Pass Labs monoblocks. But I would use those and the Pass Labs solid state preamp. I would put back in the stock steel plate jumper for now. Also check the fuses to make sure they aren’t blown. Make sure all your cable connections are good ones. Play music that is well recorded. Examples would be Steely Dan Aja and Goucho. If there still is a problem call Magnepan. Normally the highs aren’t as big an issue as the lack of bass impact. When yiu get this sorted there are other modifications that would make a difference.

Yes, the Pass gear sounds better than the PrimaLuna for sure. I'm not lacking any bass. In fact the base is what i'm most impressed with. I called Magnepan this morning. Still awaiting a response. Thx.
You’ve had these Magnepans for 5 days.  (I’ve been listening to Magnepans, almost exclusively for 40 years.). What speakers were you listening to before the Manepans?  Could it be that you (your ears/brain) had become used to unnaturally bright tweeters and the more natural tonal balance of the Maggie sounds dull?  ( Of course, this argument doesn’t account for your measurements. When it comes to  the pleasure of listening to recorded music, I place more importance on my own subjective aural experience than I do on measurements.)