Axiom Home Page Forums General Discussion Stereo M60's on a raised platform?

I have 3 M22's above the TV, and tried pointing them down to the listening position, but sound was too harsh, so I left them pointed straight out, even though way above my normal listening position. I also have 2 M22's and a VP160 mounted below the TV. VP160 aimed slightly up, with M22's straight out. Sounds fine this way.

OK this is going to be embarrassing...

As you know I've been working on the room acoustics a bit, and I had improved things to the point where I felt the weakest link in the system was now lack of amplifier power.

There was a bit of an "edge" to the sound when playing at higher volumes that I didn't remember hearing on the system I had back in the good old days (with a big-ass Marantz power amp) -- but I wasn't sure whether to blame lack of amplifier power, abused ears, abused tweeters (nothing like port abuse, don't even start) or something else. The off-axis harshness I noticed when walking around the speakers only added to the confusion.

Didn't feel like spending a lot of $$ on an amp until I knew it would make a difference, so I picked up a used Adcom GFA-555 II tonight and hooked it up. Hard to find the right words but I could finally turn the volume up as loud as I would ever want for normal listening without the system starting to sound strained (I always backed off at that point). So far so good.

The intermittent "edge" on the sound still persisted, even at the same volume levels as before, so I knew the amp wasn't the problem. That left tweeters or ears, and I knew that replacing ears would hurt, so conclusion was "hey now I have an excuse to buy a couple of those nice v4 tweeters". Obvious first step was to make sure that the new tweeters were compatible with the crossover in whatever version of M60 I had (thought it was v2 but wasn't 100% sure) so I grabbed a flashlight and looked at the back of the speakers. Music was still playing.

So I bend down and peer behind the right speaker and first thing I notice is a buzz coming from somewhere around the speaker terminals. Turns out my speakers are M60ti's, which have two pairs of terminals joined by metal strips in order to allow bi-wiring or bi-amping. The nuts on the lower binding posts (where the banana jacks were plugged in) were tight, but the nuts on the upper binding posts were loose. Bzzz bzzz.

Tightened up all the nuts (they were loose on the left speaker as well) and holy ^$%&^% the "edge" on the sound went away, even when walking past the speaker. The sound was harsh off axis because the buzz from the back of the speaker wasn't being blocked by the speaker cabinet.

D'oh !!

I can't TELL YOU how many times i've heard how loose nuts caused an issue.

JP can though.
He deals with nuts all the time.
I bet he has a cocktail solution for that too!!

There are no words to describe how stupid I felt when I found the binding post nuts were loose. I must have read 20 warnings about making sure the binding post nuts were tight so woofers & midrange/tweeters would both be solidly connected to the speaker cable.

EDIT 1 - JP makes good cocktails ? Road trip !!

EDIT 2 - oh yeah, drug company reps. Never mind.

Yes, just wait until JohnK logs on.
He could easily cut and paste his top 5 usual tips on why speakers sound "off".
I'm sure that checking the binding posts is in there.

Interestingly, having had my M60Ti for probably 10 years now and at least one or two moves (house to house, room to room), i've never had that issue, but i still use the cap in the tweeter line to reduce the high end output. I would love to hear the latest V4 vs. the Ti to see if it is worth my while to consider the changes.

Yeah, John; another reason to avoid if possible the silliness of the dual "bi wired" binding posts.

OK, so I have a new problem. I'm actually happy with my system and there isn't anything I particularly want to change. So what the heck am I supposed to do now ?

EDIT - I guess I could load all the CDs I bought a couple of years ago from (pretty sure it was JohnK's) list of great recordings and see how they sound.

No reason to be embarrassed, John. Anyone who has done this long enough has a story about missing a setting, connection, or something else that might have been obvious under different circumstances.

Thanks Mark. I'm still embarrassed though...

BTW this is getting terribly off topic but I do have to say that the bigger amp really made a difference in my enjoyment of the system. The speakers are in a large room (~4200 ft^2 for the immediate listening area) and that space opens directly into at least another 5000 ft^2. The house is mostly one big open area with bedrooms tacked on the side and back -- the floorplan has been uncharitably described as "a double-wide with a bump-out".

With the receiver's built-in amp I was playing mostly music that sounded good at low volumes, but now everything is fair game again. When playing as loud as I would want for comfortable listening, maybe 8-9 feet from the fronts of the speakers, the distortion lights *just* start to flicker dimly on the most demanding content. On this amp that apparently happens around 260W into 8 ohms.

When I had the M60s in a smaller room the power requirements seemed to be quite a bit lower and the HK 3270 seemed a lot closer to providing enough power for normal listening, although I still had to limit the volume a bit. I guess I have "just enough power" for the new listening area now, which is kinda nice and highly recommended.