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Posted By: jflores VP150 Possible Problem - 03/12/05 03:01 AM
Hey Everyone,

Need some help from anyone that has the M80ti mains and VP150 setup already. I received my speakers a couple of days ago and have spent a few hours setting everything up just right. I have done the calibration at 85dB all around with the AVIA dvd and the Radio Shack sound meter. The problem (and this is why I need your help) is that when I run the pink noise between both the M80ti and the VP150, there is a very noticeable difference in sound quality with the VP150 when compared to the front speakers and even the rear QS8s. When I put my ear up to the tweeters on the VP150 it's as if they are very low compared to all the other speakers. I spoke to Joe at Axiom and he suggested turning up the VP150 2dB but I still hear a noticeable difference in all the high frequencies when compared to all the other speakers. I even tried moving the VP150 to the rear center channel on my receiver just to make sure it wasn't a problem on the front center channel. I have tried several music CDs and again the highs are muffled in comparison to the other speakers. Can anyone tell me how close the tonal quality should be between the VP150 and the M80ti? I don't expect it to be 100% but I feel it should not be so noticeable as it is to me.

Thanks for any help,
Joe

My setup:
Samsung 50" DLP HLP507W
Yamaha RX-V3300 Receiver
Toshiba SD-4700 DVD
Axiom M80ti Mains
Axiom VP150 Center
Axiom QS8 Surrounds on FMS QS stands
SVS PB12-Plus/2 Subwoofer
Zu Julian Speaker Cables (Mains,Center)
Monster THX XP25 HT Speaker Cables (Surrounds)

Posted By: NeverHappy Re: VP150 Possible Problem - 03/12/05 03:12 AM
I had both the M80's and the VP150 and I thought they were timber matched fairly well but not perfectly. Average for lack of a better word. I can't however say that I thought the difference was as pronounced as you are describing but it was there. Are both tweeters working in the VP150?

I personally have never thought they should be different. They don't have to be timber matched as these day's that is almost a buzz word but they should be darn close.

My current set-up sweeps left to center to right with very little if any noticeable tonal change in the highs. I would hope that given the interaction between the mains and the center this would be the norm.
Posted By: jflores Re: VP150 Possible Problem - 03/12/05 03:17 AM
When I do the sweep from left to right, the sound is noticeably deeper on the VP150. The tweeters seem to be working but they are very low.
Posted By: NeverHappy Re: VP150 Possible Problem - 03/12/05 03:19 AM
You don't have some form of EQ-ing on by chance do you that would be doing it?
Posted By: jflores Re: VP150 Possible Problem - 03/12/05 03:27 AM
Hmmm. I just looked in the Yamaha manual and there does seem to be some kind of Center Graphic Equalizer. Here is what it says "Use this feature to adjust the built in 5 band equalizer so that the center speaker tonal quality matches that of the left and right main speakers. You can select the 100Hz, 300Hz, 1kHz, 3kHz, or 10kHz frequencies". It seems to be set at the default setting (all flat). I will play around with this and see if it makes a difference. Thanks!
Posted By: Ken.C Re: VP150 Possible Problem - 03/12/05 04:15 AM
Yeah, I'd try to take out all of the Yammie's YPAO stuff other than the distance and volume settings. That's probably what's going on. Either that or there is something wrong with the VP.
Posted By: Ajax Re: VP150 Possible Problem - 03/12/05 05:19 AM
Joe, if I understand things correctly, no speakers of such different size and shape are going to sound exactly the same, particularly with just pink noise going through them. Same for the QS8s. A better way of saying it is that the pink noise is going to accentuate the differences. Just get them properly calibrated and start enjoying movies and music. Trust me they are matched as well as speakers of different size and shape can be. Not perfect, but perfectly OK. Relax and enjoy. Perhaps there IS something going on with the receiver. But, if there is a problem, it is NOT with the speakers.
Posted By: BrenR Re: VP150 Possible Problem - 03/12/05 06:49 AM
In reply to:

Hmmm. I just looked in the Yamaha manual and there does seem to be some kind of Center Graphic Equalizer.


Yup... I've got my centre (a good scratch built one from my last kick at home audio just out of high school) - it's two 4.5" poly woofers and a 3/4" dome tweeter. It's pretty nasal compared to the Axioms, so I've got a slight EQ on it. Not the best solution, but until I pick the lock on my wallet and order a VP100...

Bren R.
Posted By: mwc Re: VP150 Possible Problem - 03/12/05 03:36 PM
Barring setup, calibration, and speakers problems, I think Jack hit the nail on the head when he says "no speakers of such different size and shape are going to sound exactly the same". This is why most "experts" recommend three identical speakers across the front. To my ears, I've never heard a "dedicated center speaker" that sounded "right". Aside from the tonal/timbre match problem with small center speakers, is the annoying problem of having the dialog seem to come from below or above (depending on where it is placed) the screen.

If you really want know what a seamless front sound stage sounds like , try the "phantom" center mode just for grins. it's the next best thing to having three identical front speakers (at least for an on axis listening position). You maybe one of a growing number of people who have discovered that they don't like center speakers.
Posted By: alan Re: VP150 Possible Problem - 03/12/05 04:41 PM
Hi Joe,

As Ajax has correctly pointed out, pink noise is an extremely critical test signal (and useful). Please experiment with placement of your VP150. It is possible to find a location where you can get a seamless soundstage with the M80s (this advice also applies to the VP100). I've done exhaustive experiments with both models as well as using identical speakers across the front.

Placement issues and room/boundary effects are such that even if you use identical speakers across the front, the center will never sound exactly identical to the left and rights when you use pink noise.

But by trying different locations, you can get the timbral match with the VP150 and your M80s close enough that you will not notice timbral colorations with movie dialog or vocals (or instrumentals) when all three are running.

Regards,
Posted By: bridgman Re: VP150 Possible Problem - 03/12/05 05:01 PM
I was just about to start a thread with the same question when I saw this. Now that I have Axioms all round again (60s, VP100, QS8s) the sound is very consistent between speakers and the surround modes for music sound great again (although I still think I slightly preferred the M2s for music).

When I run pink noise around the speakers, though, the VP100 still sounds quite different from the rest (probably caused by the fact it has a shelf 6" above it and a TV below it ?) but there are also fairly significant differences between left and right channels for the same speaker type (eg. left and right M60s sound different, for example).

I haven't had time to swap the speakers and see if the sound moves with the speaker (it probably won't -- placement in the room is not symmetrical) but before I mess around with that has anyone else heard the same thing ? Talking about a fairly significant difference in pink noise sound between left and right main or left and right surrounds.

Note -- I'm not even thinking about the surrounds right now since one is hanging on a wall and the other is still stacked up on a pile of soup cans
Posted By: Michael_A Re: VP150 Possible Problem - 03/12/05 06:17 PM
Guys,

While the pink noise is playing, change the delay (distance) settings for the center channel. You can hear the changes in tone as you change the setting. If you can't get it exact, and your reciever has only 1 foot adjustment steps like my HK630, move the center forward or backward a few inches, then repeat the delay/pink noise test.

Also, make every effort to align the actual center with the phantom center created by the front speakers. I found that if the two "centers" do not align with each other, it will mess with the sound. I guess most would describe it as "muddy". An easy way to test the side to side location is to play music and switch from stereo to DTS, DPLII, or Logic 7 on the fly. When the imaging (particularly, the location where the lead singer's voice is coming from) stays pretty much the same, you have it right.

Pink noise contains some energy in the lower octaves that the VP series can't cover as well as the main speakers can, so the pink noise will never sound exactly the same. This is not a problem. The 2 will sound identical when playing frequencies that they can both handle equally as well.

I almost sent my VP-150 back until I found out what the heck was going on (which took hours and hours). No way will I give it up now. The center is the one speaker that guests always make positive comments about when they come over to watch movies. When we listen to stereo music, they always think the vocals coming out of it sound fantastic as well. That is until I pull the cable from the back of it to show them that the M60s are placing the singer there without any help...
Posted By: Rock_Head Re: VP150 Possible Problem - 03/12/05 06:19 PM
The quicker you eat that soup, the sooner that QS8 get's hung on the wall!
Posted By: Ken.C Re: VP150 Possible Problem - 03/12/05 06:29 PM
Wow, that's a really informative post. When we get that center... It's going to be harder than I thought, isn't it?
Posted By: bridgman Re: VP150 Possible Problem - 03/12/05 09:12 PM
>>The quicker you eat that soup, the sooner that QS8 get's hung on the wall!

I already bought more soup. What I need to buy is wood screws...
Posted By: Ken.C Re: VP150 Possible Problem - 03/12/05 09:16 PM
They're difficult to find on Canadia, huh? Must be tough living on an island...
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