Hi,

New guy here. I got my M60ti speakers just about the same time time the NAD T742 / T512 combo arrived.

I can't say I'm not pleased. By the way, there is nothing like the smell of new electronics and speakers; it has it all over a new car smell.

First, the good news. I really like what's not there; the effortless and competent sound lets you know there is no straining here. The sound is transparent even as the volume is turned up. No grunting, no straining at all.

I put Paul Simon's "Graceland" on. I'm more of a classical kind of guy but "Boy in a Bubble" excersizes things at both high and low ends while sounding very well indeed all by itself.

The drums are very crisp, accurate and taut. Very reasonable bass for speakers that look like gasping guppies when driven with a 20Hz sine wave and grills off.

All in all, very comfortable speakers because of their transparency, as in you don't know they are there.

Shortcomings. To my ear, one major and one minor one.

Major first; these speakers are way too bright on the tweeters. Sibilants absolutely hiss; I have to cut treble by -8db for things to sound decent. I'm a mid-50's guy who never wrecked his ears at concerts and can still hear 16-17 kHz tones at reasonable levels. It could be my problem.

I know it's not the amp. I'm a EE and have the equipment to check. Driving the amp with a 100 Hz square wave gives a remarkably accurate output; enough to surmise a flat output past 20kHz. An FFT analysis of a loaded output confirms it as well. So the over-bright treble response rests with the speakers. In my opinion, this needs to be balanced and brought more into line with the rest of the response.

Minor point. Bass needs some assistance. This is very frustrating because only another 5 to 7 Hz of bass extension would satisfy entirely. No point in turning up the bass because the sound gets boomy, sloppy and the drivers look like guppies again trying to cope. I have an SVS 20-39 coming in Tuesday to see if it can be of some assistance.

All in all, I'm very pleased. I auditioned other speakers 3 times the price and more I didn't feel were the equal of what I bought. I didn't buy the Axioms because they cost less; I bought them because they sounded better.

Sorry for the long post.

Mariss

Hey, long posts are cool. Welcome!

Try various recordings; a lot of stuff is mastered hot, and the M60s are (from what I've read) not forgiving. I've heard the M22s, which are supposed to be like miniature M60s, and I've certainly heard what you are talking about. My M50s are a bit more forgiving.

I think the SVS will make you very happy, bass wise. I was running my M50s for about a week without a sub, then realized I was missing stuff... so I turned the sub back on.

Mariss, welcome. Hey, maybe that smell is the "burn-in" that some audiophiles insist has to happen? I'm practically 100% a classical kind of guy, but I did try some hotly recorded pop items from the library a couple of years ago on my M22s when I read some complaints about the b word(bright ist verboten, along with metallic). I sort of saw at times what they were talking about, although it was clearly the fault of the recordings, not the speaker, and I experienced nothing of the sort on well-recorded classical items. One of my receivers has tone controls with variable turnover frequencies selectable and I found that setting the treble maximum cut at 6KHz was the most effective(e.g. 12KHz was another choice available)to make the lousy CDs less objectionable. This tended to confirm some previous reports that it was the upper midrange/lower treble and not the 10KHz+ area that was the problem.

You haven't said if you experienced the problem with more than that one CD, which I'm not familiar with. Some have suggested inserting a resistor before the tweeter to drop its output level uniformly across the entire range, but that's something I'd never do. Equalization on objectionable recordings only would seem to be a better idea.

Stick that 20-39 into the corner and cross to it at 80Hz and you'll certainly have more than enough bass. Enjoy.

See, I am the direct opposite of you. I am 43 and have been to alot of concerts in my life. I think I have trouble hearing the high's sometimes. I turn my Onkyo up to +12. I have the 60's also. I absolutely have a different experience than you. I love the tweeter highs and hear no siblence in these speakers. Turning them back makes my music flat and I listen to alot of different types of music. How is your NAD working with the 60's?? I am interested in either the model you purchased or the 752's. Can you give me any info? By the way, can you really hear 5-7 hz of bass extension? The most I ever turn up my bass settings are +6 and that is on the absolute best recordings.
Thanks....

I think you're post was all and all, a pretty fair review.
I own M60's too, but.... the tweeters, in my opinion....are
fine. In fact, the only adjustment I have made to my a\v reciever was to "up" the treble a bit. I have a pretty good ear, and like the "metallic" sound of cymbals, etc. of the M60'S. [some speaker's tweeters can only make a hiss type sound instead].
I would check the "cd's" sound quality first, when it comes to this, as it makes a HUGE difference in the sound of a system.

Mariss,

I'm my my 50s too, with 60s. Wait......or is it I'm in my 60s with 50s. NO, I've thought about it, and I'm sure I'm it's 50s WITH 60s (I think).

Several things. First, give yourself a little time to become acclimated to the sound of these speakers. You've probably been used to speakers with a very different frequency response.

Secondly, try turning down the volume juuuuust a little. With lesser speakers, I found it necessary to crank the volume to able to satisfactorily hear all the highs, mids, and lows. So, I was inured to listening at that volume. I discovered that, with my 60s, I'm able to listen at a lower volume than that to which I had become accustomed and still be satified with, if not amazed by, the 60s' balanced frequency response. It did take a little time to be comfortable listening at slightly lower volume levels, but my neighbors are very grateful that I did.

Next, never underestimate the effect your room's dimensions and furnishings can have on the response of your speakers. Sometimes moving speakers or furniture just a little one way or the other can cause a substantial difference.

Also, John's point about poorly mixed, or mastered, recordings is a good one. Many recording engineers boost the highs in a recording to compensate for the fact the majority of speakers extant are lacking in that part of the frequency range. Try a variety of CDs and I think you'll see what I mean.

Finally, when the SVS arrives, I don't think you'll experience any lack of bass response. Be sure to secure all knick knacks and other breakable objects. If you have not already done so, pick up a Radio Shack sound pressure level meter, and an Avia or Digital Video Essentials disk (be sure to search the web for the best prices), and calibrate all your speakers. Even if you're just using the 60s and the SVS, you'll want them balanced, and with LFE, you just can't do it accurately by ear.

Post Pictures if you can. We LOVE seeing pictures. Stick around and keep us posted on how it goes.

Mariss,
I had the very same feeling about M60s untill I changed
nothing-wrong-about-16G-HomeDepot-wire with
12G ( not a Monster or likes ) but still a quite good of a quality wire.
Highs are behaving, bass is fuller now.
Oh, forgot, you might need to move to another house :-)
(If your "music space" is as badly suited for SOUND as mine )

Mariss, welcome to the abyss . You are gonna LOVE the 20-39. I also concur with the purchase of bulk 12 or 14 ga from Home Depot. You don't need Monster Price wire.

As far as the sibilance is concerened, I haven't experienced ot with my M60s. Crisp, clear but not bright (of course, I am using my ears and not yours ). If it continues to be an issue after you have taken the time to let your ears acclimate, you might try repositioning the M60s in relation to your center (if you have one). I remeber Alan mentioning something about this in a thread I can't find. Moving the 60s a bit in front of or behind the center solved the problem. Also, give the good folks at Axiom a call - they live to help you with this type of issue.

Mariss- congrats on your new M60's. I just want to comment on the brightness issue you seem to be having. I own a set of M60's as well, and earlier in the year I had to replace both my tweeters due to them dying on me when my former amp decided to blow up.

I received the new tweeters and installed them immediately that night (2 days later thanks to Axiom's incredible customer service) and the first thing I noticed was that the same reference tracks I used to test my system made my ears hurt because they sounded incredibly shrill. I had to stop listening for the night because it wasn't enjoyable at all. One call later to Axiom and I had the tweeter resistors sent to me.

But before I was able to install them, I let the system run at low volume for some time over the next few days. I took another listen to the same tracks the night I was planning on installing them, and already I noticed that the harshness wasn't as bad as it was the first time I played the new tweeters. They seemed to have leveled off nicely. So my suggestion is to give the speakers some time to break in. I'm sure that someone else will chime in here and tell you that the break in period is a fallacy. However, I know that the new tweeters sounded much more harsh than what my system sounded like previously on the same recordings I was playing. But after a few days of use, they were much less harsh sounding and fatiguing to my ears.

With that said, I installed the resistors anyway. I still have them on the tweeters to this day, mostly because with them on, the midrange seems more prominent to me which is quite enjoyable.

Let the speakers play for a few hours a day when you're at work. After a few weeks, sit down and take a critical listen to them to see if you notice a difference or not. You may be surprised. And if you still seem to be having an issue with them, call Axiom and have them send you a set of resistors for the tweeters to see if that maybe helps the problem. Post your results here if you wouldn't mind. I'm interested to see how this turns out for you.

Good luck.

-Kevin

Kevin,

How much did those resistors cost and how hard are they to install? Also, did you feel like you were giving anything up soundwise?

The resistors are free of charge from Axiom. Just give customer service a call and they'll send you out a set.

As far as sound is concerned, I still have them on to this day and I should probably take them off and do a critical comparison when I've got some extra time. But with them on, I really think my system has never sounded better. I would probably say that they haven't comprimised the sound or that they haven't made the speakers sound drastically different. The best way to describe it would be that the highs are less fatiguing now.

If you get a set, please post your thoughts on them. I'm interested to read what you think.

-Kevin

Well, the NAD742 lasted less than a week. I had instrumented the amplifier to measure its power output, frequency response flatness and distortion with the M60s attached. This involved driving the input with a low distortion sine output from a function generator while the output was probed for voltage and current.

A Tektronix TDS360 digital sampling scope was used; CH1 measured the NAD742 ouput voltage while CH2 connected to a Tek 503 Hall-effect current probe to measure output current. Data was taken at 10, 20, 50Hz, 100, 200, 500Hz, 1kHz, etc.

First the good news: At lower frequencies the NAD742 output began clipping at +/-35 volts peak. The current was 4.6A peak meaning the M60 impedance was 7.6 Ohms calculated. RMS power output was calculated as 80.5 Watts before clipping. Harmonic distortion measured 0.9% at 500Hz and 80W.

The bad news (my stupidity): I left the output amplitude at +/-35 volts while I swept the frequency from 1kHz to 2kHz, my next data point. The first sign of trouble was the speaker current going to zero phase angle and rising to 16.8A. The second (and final) sign of trouble was a blue flash of light from a blowing fuse inside the NAD. The scope hardcopy showed 294 Watts RMS being deliverd to the load at the time of failure. The speaker resistance calculated out as 2.1 Ohms at 2kHz. I opened the NAD and measured damage consistent with secondary avalanche failure of both output transistors. The NAD was a serious pain in the rear to get to the failed devices; it had to be nearly completely disassembled.

What I learned: It's really bone-headed to input a continuous sinewave to drive an amp at high power levels until you have mapped the load impedance versus frequency characteristics. Second, I was surprised a premium amp does not have SOA protective shutdown. SOA limits are published for power semiconductors; it does not take a rocket scientist to fashion a protection circuit to prevent this type of failure.

Mariss

I saw that bright blue spark - purple actually, the first time I powered up my Anthem PVA 5 amplifier. The Purple Bolt was accompanied by a great whomping sound from the amp. Anthem replaced it no questions, just a bit of head scratching.

BTW, what source are you using for material which produces sibilance?

Well I'm laughing, but only at your articulate, self-deprecating, and humorous description of the catastrophe, NOT at the catastrophe itself.

I would wager money that there isn't one person on this forum who, at one time or another, hasn't stuck, figuratively speaking, his finger in the electrical outlet. Overlooking the fact that it was your knowhow that precipitated the problem, at least you have the knowhow to repair it. I'd be out the cost of the unit AND the cost of the repair.

Hang in there.

The only sibilance presently audible is from the choice 4-letter words I'm uttering about myself. The M60s have fallen silent until I repair the wounded NAD. I cannot in good conscience play dumb and try to foist it off as a warantee repair. Also, it builds character to clean up my own mess; it'll help remind me not to do something as stupid as this again.

While on this subject, any recommendations for an integrated stereo amplifier or stereo receiver? Denon, Rotel, something else? I really didn't want an AVR as it turns out; 2 X 125W makes more sense for me than 5 X 50W. I may give the NAD to my son after I fix it. He is into all that 5.1 stuff, I'm not.

Mariss

Kevin,

Thanks for the info. My M22's are supposed to come in mid-August, but I think that I will send the $40 tomorrow so I can get them sooner. You never stated how hard they are to install. I'm decent with my hands, but electrical components scare the hell out of me, that and I don't want to screw up my new speakers. I like the forward sound that they are supposed to present as well as the clarity and soundstage. Based off of descriptions, I think I will love these speakers. It's the alleged schreeching highs that worry me. I figure the resistors would help alleviate the problem. I will try to do extensive listening without the resistors and then try them with them on and see if the sound is improved to me. While I'm doing this, I will try to A/B the PSB image 2b's and do a comparison. Hell, I might even A'B my old Bose 301's for shits and giggles.

Mariss,

If you liked the NAD sound, their integrateds get very good reviews. The C372 would be a good option.

No worries. I didn't realize you were asking about the resistors for you M22's opposed to the M60's. I'm not sure, but I thought the resistors were meant mainly for the 60's or the 80's. Not that you can't use them on the 22's, but moreso that you probably won't need them. I believe the tweeters are different between the 22's and the 60's (or 80's) which is probably why I thought the resistors were meant for the two larger floor models.

But with that said, if you do get them they are incredibly easy to install. You just need a hex/allen wrench to remove the screws on the tweeters. Be sure to turn off all your equipment first. Remove the tweeters. Then insert the connectors in between the tweeters and the correct wires. The end of the resistor caps have connectors that only work one way. There's no way for you to get them installed incorrectly. Brilliant, especially since I had the same question as you did about them.

Good luck, regardless. Let us know how you make out.

Nope, all of Axiom's speakers currently use the exact same tweeters.

Very interesting. You learn something every day. Thanks for the info.

-Kev

Kevin, that was my first impression as as well; "incredibly shrill" would be the words I'd use. What I'm not sure about now is it may have been operator error. I got a NAD T512 DVD player at the same time as the T742 and I connected the DVD out to DVD inputs on the receiver. I now wonder if I should have connected to the CD input because I was playing audio CDs. Maybe the DVD inputs do some kind of Dolby Voodoo.

I'll find out soon enough. The T742 emergency surgery is a success; just set the output stage collector bias and it is being sutured up right now. Hopefully I won't have that one screw left over, wondering where it should have gone and was it important.

The damage was a 2SC5198, 2SA1941, a pair of 2SC1845s, an MPSA06, MPSA56 and two 0.22 Ohm, 5W resistors. Pretty much every semi in that power amp channel. I'm kind of appalled that single-sided phenolic boards are used. I had expected double-sided, plated thru hole fiberglass boards.

The SVS 20-39 just arrived, so I'll see in a day or two how everything will sound now.

Mariss