Axiom Home Page Forums General Discussion Advice from Axiom Owners Distortion Question (Dave Matthews disc)

Guys, I spent a great Friday night with some friends enjoying the Dave Matthews/Tim Reynolds Live at Radio City on Blu-Ray. As many of you know, simply awesome stuff! Thanks to all as it was this forum that pointed me to purchasing that disc a few weeks ago.

Now to my question - during the first encore just before Dave plays 'Some Devil', I noticed quite a bit of distortion coming from my tweeters on my W22's. Has anybody else noticed this? I am just trying to determine if it's coming from the audio track itself or if I should be contacting Axiom. I am listening to the Dolby HD track. If I put my ear right at the tweeters I believe I can here distortion on other tracks as well, but it's really obvious from the listening position for this particular track intro. Please let me know if I'm going crazy!

It could be a number of things causing this. Do you notice this only with this blu-ray? How does other material sound from the listening position as well as at your ear directly to the tweeter? What does it sound like a hiss/buzz or more "scratchy" sounding. What are you powering your system with and how loud are you listening (to rule out distortion from receiver clipping).

Hi doc.

It's one of those things that almost becomes 'mental'. Now that I have heard this, I am constantly listening for it.

To answer your questions though - I have not had the opportunity to sample with other material yet, so it's just been the radio City blu-ray with the Dolby HD track. Volume is not excessive - running avout -30db, my usual range for movie watching - which equates to about 80 dB. With my ear next to the tweeter I turn it down to preserve my hearing! Clipping should not be an issue. Also, it's a new Pio SC-05 which has the digital ICE amp so should not distort anyway. it's not a hiss or buzz, more 'scratchy' as you put it.

That would rule out any clipping. It sounds more like a bad tweeter. Is this scratchy sound only coming out of one speaker or both.

You can also try removing the tweeter and look for a loose connection/wire.

Coming from both - I even swapped my L and R speakers just to see if anything followed. I learned it is more prominent in the right channel (even with speaker swap), but present in both speakers' tweeters regardless of position. I am curious though if there is distortion in that particular track or if it is only a result of blown tweeters. I have verified as best I can that my center (W150) and QS8's are all ok.

Which leads to my next question - what would cause blown tweeters? I've only had my Axiom's since April this year. I've done my fair share of listening to movies and music, but have not had any 'pops' or other sonic irregularities that I am aware of that would cause the tweeters to blow. Is it just my dumb luck?

You can try removing the tweeter in one of the W22's and check to see if the connections are secure. That is the only other problem I can think of besides a bad tweeter that would cause a scratchy sound. It is very rare to have 2 bad tweeters or 2 loose connections but it is not impossible I guess. Bad luck, most definitely.

Cheers!

OK - update - I think I just answered my own question. I just realised I can listen to each of the tracks on the DMB website. Even listening to compressed streaming over the www with average headphones there is no trace of the distortion I am hearing on my home setup - I guess it's not in the track. On the flip-side it makes me realise (again) how good the Axiom's sound. Aside from my current distortion issue there is a world of difference from my average headphones in the office to my home axiom setup! Guess I'll email Axiom now...

Dan,

This is an interesting issue. I have a pair of M3s, and have also noticed a scratchy sound from the right speaker on certain tracks. I'm a recent owner as well, so I'd be interested in hearing what you learn from Axiom.

-Nathan

Welcome to the Axiom Club Nathan.

After further investigation and closer listening - and listening to the same tracks through the DMB website (as mentioned in my post) I am sure both the tweeters in my W22's have 'blown'. It is more obvious in some tracks than others, but if I turn the volume down and put my ear right next to the tweeter I can tell something does not sound quite 'right'. If I do the same with my W150 center channel the signal from both tweeters sounds normal (not scratchy).

I have emailed with JC and Axiom has already sent me two new tweeters. I will install them this weekend to make my system whole again.

I have cranked up my system in the past (as all of us do ), but I am really not sure when or how my tweeters were damaged as I don't recall any particular bad moment (hiss/crackle/pop) that could have damaged them. Nor did I have the system ridiculously loud - just louder than usual for short periods of testing.

Oh well, I'll definitely be more aware with the new tweeters as I don't care to repeat this situation.

BTW, how do you like the M3's? I am thinking of them for a future bookshelf setup without a sub.

Thanks, Dan. I think I might email Axiom as well. Are the tweeters difficult to install? Hopefully instructions would be included.

The M3s are my first pair of high-quality speakers, but I enjoy them quite a lot. I listen through many styles, from classical to metal, and movies, they do justice to it all.

I recommend them for a bookshelf setup.

Now I just need (or want) a high-quality sub and a high-res (SACD/DVD-A) player.

I can't imagine it's difficult to swap the tweeters, though I can let you know after this weekend!

Are you satisfied with the bass extension of the M3's for music? I was specifically thinking of the M3's vs. M2's/M22's as I will need to run without a sub for the upcoming bookshelf setup.

I was actually fairly impressed. I broke them in with some bass-heavy rock/metal and found the extension to be more than adequate.

I've seen them described here as having a small bass hump, which may be the effect you're looking for. I find them to be attractive and the perfect size for a bookshelf application.

Tweeters are very easy to install. Remove the four screws and carefully pull out the tweeter. Next carefully detach the wire connectors. One connector is bigger than the other so wont be able to connect the wires in a wrong manner. After that, reverse the process. Very simple procedure. Enjoy and hopefully this solves your problems.

Hi Dan,

This thread and your tweeter problem is really puzzling. You could isolate the problem immediately to either the Blu-ray recording or the tweeters if you have good headphones, which can reveal inherent distortion on recordings faster than using loudspeakers. Turn off the M22s and listen on the headphones. If you still hear the distortion, then it's on the Blu-ray master (not unheard of; I have a number of CDs where you can hear the mike inputs clipping). If you don't hear the distortion, then it's the tweeters.

If the problem were the tweeters, you'd hear the distortion with other CDs. Have you tried other material?

Regards,

Alan

Hi Alan,
I can hear it with other material, however it's REALLY noticeable on the one particular track. On other material it seems to be much less obvious.

I had not thought of trying headphones from my receiver on the same track - that's a great idea and I will try that as soon as I get home (I'm currently traveling). However as mentioned I did a similar experiment by listening to the same track from the same album from the Dave Matthews web site with my headphones at the office. I could not hear the same distortion I am hearing at home.

Thanks again - I'll let you know what happens.

It's undoubtedly a different compression scheme on the site as opposed to the disc, and it could be different mastering. I'd say definitely check it as Alan suggested.

Fully agreed - I plan to do just that as soon as I manage to get myself home!

I'm not positive, but I don't think the encore (for some odd reason) is done the same as the rest of the disc. I believe I've noticed the same thing. I'll check it out again and give you my feedback.

I'll need to check my speakers as well, since I've noticed it faintly several different times. Please let me know if there are certain test principles I should be using.

I don't 'recall' such noises in my copy of that recording but honestly, I rarely get all the way to the encore unless it's just playing as background music and I'm not listening that closely.

The only time I regularly get a distortion like sound is when playing Rockband. Despite the praise for Rockband's use of the original masters, in many tracks I'd swear that I have a tweeter problem to the point it's scary. However, because I've never hear it in any other material, I'm convinced it's just in the game. I think it might even be the crowd clapping that they add in causing the problem.

Laingn2,
What Alan suggested is a very effective way to determine if what your hearing is in the speakers or in the audio track.

I have not swapped my tweeters yet (it was my son's bday and we had company all weekend), however I did manage a quick listen on my W's and with my in-ear head phones.

I learned there is definitely distortion in the 'Some Devil' track using the DolbyHD audio track on the Blu-Ray disc. My guess is that it's purposeful distortion that Dave is using on his guitar and that it's not added in the studio mastering. However it still sounds different (more distorted) on my W's vs. the headphones. I am still trying to track this down.

Back to your question - listen to the same source through your speakers and with good headphones as Alan said. Just watch that your receiver doesn't try to automatically switch modes when head phones get plugged in to try and keep it as fair an A/B comparison as possible. Mine (a Pioneer SC-05) automatically downmixed the DolbyHD to stereo for me when the headphones were plugged in. To make sure what I was hearing was real I also checked the stereo mix on the BR disc with my AVR in stereo mode so it would not switch modes when the headphones were plugged in. Good luck!

The 22s ARE known as being a very revealing speaker. I'm not surprised that some stuff - good or bad - isn't more evident on the 22s...

Good heads up for me on RockBand Murph. I'll try not to let that scare me further as we also play both RockBand and GHWT. Thanks.

I hear ya Mark. There's still something that doesn't sound quite right however - plus i don't think this disc would be getting such rave reviews everywhere (including this forum ) if there was bad mastering in the mix.

It could still get rave reviews because we are all getting so used to poor recordings that a disc with very minor flaws can still get rave reviews, especially since everyone has different tolerances to such things.

I don't have Dolby HD, so I won't chime in on that track, but I have fried a tweeter before. No pop or other drama, just stopped making highs. But it was dead, not just on some material. If your tweeter is bad, its bad. Just play some other music and listen closely. You can't hide a dead tweeter on a two-way speaker very easily.

That very same thing happened when Tommy Chong got sent to prison!

Hi cb919 and all,

Thanks for your follow-up, and yes, the Axioms are indeed very revealing speakers.

If we assume for the moment that the distortion is inherent to that track on the Blu-ray disc, there could be a number of reasons why it was included. Since it's a live recording, that may have been the only "take" available, and the producers and artist figured that most people wouldn't detect it.

It could be that the control-room monitors during the mix didn't reveal it, or that the mastering guys didn't hear it. For example, I have some CDs that have audible rumble from the air-exchange system in the concert hall, only audible when you play the disc on a system with a really excellent subwoofer. Most control room loudspeakers do not use subwoofers so the recording engineer would have been quite unaware that there was low-frequency garbage on the master. I have another that has audible foot sounds from a pianist using the pedals. The mike used for the piano wasn't isolated enough and the floor in the studio conducted the vibrations up the mike stand into the microphone--again, it's only audible when played on a system with a good sub. There are other examples of mike input clipping that I own. In one case, even though the recording engineer heard the distortion on the vocal mike, the artist (the blues singer, Joe Williams) refused to do another take, so the Cd was issued as is. The late John Eargle, a highly respected recording engineer who wrote one of the seminal texts on studio recording, told me that anecdote about that Cd of Joe Williams when I inquired about the audible distortion on a vocal peak.

Regards,

Alan

I listened briefly to that part of the Dave matthews and tim reynolds bluray through my m80's, and then flipped back to some previous songs on the bluray. It definitely seems to be recorded with less quality... but maybe I'm just hearing things.