Axiom Home Page Forums General Discussion Home Theater Center Channel Sounds Hollow

This is a general question as I experience the same issues with other speakers, but why does the center channel always sound hollow and high pitched? It sounds completely out of sync with the other speakers. I assume this is intentional, but it does not sound as deep as the theater.

I'm using a Pioneer SC-07 with a VP150 center. I can use a different receiver or speaker combination and it's the same.

Can you tell us about your center channel's placement? Speaker placement had an enormous effect on how a speaker will sound in a room.

I know its not generally recommended but have you ever tried setting your center channel to "large" in the receiver settings so it runs full range. This might help.

A-ok, if this is present with different center speakers and different receivers, then maybe placement is the determining factor, as Peter suggests. One quick experiment would be to turn your VP150 upright and listen to it in a vertical configuration to see if the effect that you described persists.

aok, the center is primarily for the dialog/voices in movies/music, so it does not need to be full range. How do you have your settings in the receiver and where is it positioned?

It's roughly an 19'W x 18'L x 12'H room with a standard 7.1 system with the sub behind the couch. The setup takes up 10'W x 14'L of one end of the room.

I also have the 2 M80v2, 4 QS8v2 and EP500v2 and they've been calibrated. The fronts are large, while everything else is small. The fronts are 13' from my sitting position.


It's located inside a cabinet exactly like the BDI Avion except it's not enclosued by a a front door and screen. The only screen covering the speaker is the oem screen.


I've tried both. I can't tell much of a difference but I think large seems to make it worse.

I don't know...the theater sounds like it has more depth.

As an experiment, can you pull the speaker forward so it hangs outside of the cabinet by about 2 inches?

I think the problem may be with your receiver or its settings or DSP selection.

The VP150 should not sound "hollow." It sure presents an impressive array of drivers for voice, music or effects.

I don't think the cable will go out that far, but I'll give it a shot.


It was the same with my Denon 3806. With my current receiver (Pioneer SC-07) I always use THX Ultra2 Cin. It's been calibrated via MCACC, so I wonder why it could be off.

try wiring it out of phase

Just as a test, try turning off the EQ portion of the MCACC settings. If the mic got a bad reading (possibly from interference from the cabinet), it could be heavily EQing some band, which would also result in a hollow sound.

Mine sounded a bit boxy when it was WAY up high on top of my old big screen. Now that it is roughly parallel to the main speakers upper woofers it sounds muy fabuloso. An insane improvement in sound quality for zero dollars.

I'm betting placement is less than optimal.

I pulled the center out and it does not make a difference. I turned off MCACC and it sounds much more full. With MCACC on, it filters out all the background noise and focuses on the vocals and so it sounds more hollow.

I guess in the end, the hollowness is probably all subjective to me and I think this hollowness is how it is supposed to be. But the tuned focus on the vocals sounds too studio. It stands out too much and therefore artificial to me. For example, there can be a scene with explosions all around, but the guy yelling sounds like he's sitting in a quiet and calm studio. It does not blend with the scene to me.

Some good came out of this because I found that I like it better with MCACC off. To me, the center does not stand out as a loner from the other speakers and it just sounds more full and synchronized with the other speakers and the surrounding scene.

Hollow is all wrong. The VP150 should not sound hollow. Something is wrong with your set up. Speaker, source, position, amp, processing section, something.

The VP150 for all the faint praise it receives around here is an excellent center channel speaker. I'm watching/listening to 24 right now, and this VP150 sounds terrific.

If you haven’t already try turning the VP150 off in the receiver and run a phantom center as an experiment. If while sitting in the sweet spot voices stop sounding “hollow” then something is certainly not right.

I’ve used the VP150 in three rooms and gotten three different results one excellent, one average (for a horizontal center) and the present one which I think is exactly what you describe. Voices sound like someone is talking through two tin cans connected by a string or somewhat high pitched and edgy. Also voices sound like they are coming from through a tunnel with the source somewhere behind the TV getting worse the further off center I sit. Note I get this result with the VP150 sitting in the open about 4 feet from the nearest wall and with both a Denon 2807 and an Onkyo 3007. Also in all rooms Audyssey made it sound worse.

Like I said above it’s also sounded pretty average in my apartment living room where the voices were a little higher pitched and the overall sound was less dynamic than my M80s. Both of which were subtle enough I didn’t notice until I tried a phantom center with my M80s by accident. In my apartment bedroom my VP150 blended perfectly with my M22s I was using as mains there. So in my experience it’s very sensitive to placement and room acoustics.

Again try running a phantom center and if that makes the “hollowness” goes away then maybe you should consider trying a M22 as a center if you can fit one or a VP100 which I have no experience with but have never read of anyone having this issue with it.

Cheers,
Dean

Its so interesting how much the VP150 seems to be effected by room placement. Much more so than the rest of Axiom's offerings. While Axiom has supporters and detractors for ALL of their products, the 150 seems to be the one exception where even the biggest fans of Axiom products can be at odds with it. There is truely a love/hate relationship with the VP150 on this forum.

I love mine, even bolted to the ceiling. And many others here wouldn't trade theirs in on anything else either. And hearing these claims tend to baffle us, leaving us wondering if they got a bum unit or something. "Hollow sounding? How could anyone come to that conclusion..." is the first thing that pops up in my head when I read these cases. Similar to what most M80 owners thought when Bob came on here and complained about his M80's sounding way too harsh, or bright. "Bright??? How could anyone consider the M80 as a 'bright' speaker"???

And yet there is a rather large crowd that gets less than stellar results with their VP150's. A large enough crowd that it can't just be dismissed as a fluke. So no matter how fabulous it works in my personal HT, it makes me wonder if it should in fact be redesigned to perform better in a wider range of applications?

Or perhaps the problem isn't as wide spread as it seems here in this forum. Maybe the fact that we are in effect in the complaints department means we're subjected to a large percentage of those who are unhappy with their 150's, but don't hear from the majority of customers who loved theirs but never bothered coming on here to tell us, gives off the impression that its a lot less popular than it really is?

Either way it is disappointing to hear from those customers who aren't getting great results from their VP150's because I want them to be able to experience the same remarkable performance that I get from mine.

I suppose working in the complaints department of ANY company would be a bummer eh?

I think you have to look at the environment that a center channel is subject to. Many people put them in the least desireable place and expect it to sound just as good as the mains. A center speaker for most lives it's life in one of the least desireable positions as far as speaker placement goes, always close to a highly reflective material of some sort, ie. entertainment center, TV, floor, ceiling, but in the case of the OP he has already stated the problem was Pioneer's MCACC EQ system.

I think we can all remember that back in the day when center channel speakers became an item in Home Theater, in reality, because of space issues and positioning, they really always have been a "compromise" in sound. That was primarily because of the advent of Dolby Pro Logic which still had sound and bandwidth limitations.

Once DD and DTS came in to existence with their full-range discrete channels, at that point to me, all bets were off. Now we have "lossless" audio with even more dynamic presentations so we can't say anymore the center channel speaker is the most important yet still put these sound and size limitations to it.

Bottom line for me has always been, if you can't use a similar speaker to the L/R, at least have one that has big enough drivers so you can run it full-range without strain. There are center channels out there that do provide these features without being overly large. I am hoping for that from Axiom in the near future. In my opinion and in current applications, five and a half-inch drivers just aren't big enough anymore.

The idea that the front speaker array really needs to be full range has been on my mind for the past few weeks. The problem I see is that generally to develop low frequencies at meaningful sound pressures requires large drivers. Large drivers mean large enclosures. So, then how do you have your display at a reasonable height but still have a rather large center channel? The only solutions I've thought up are to use a projector and a sound transparent screen or to place your AV gear somewhere other than below your display.

The other thing I've been thinking about is how people say that low frequency sound is "non-directional". I would like to know where the cut off frequency for this "non-directional" sound is. I suspect it's lower than THX's recommended 80hz.

It's actually about 100 Hz, so 80 is a good point.

I have my 150 mounted up near the ceiling above my screen angeled down right at me. It is mounted to a board that spans a couple of pillers that go from a 3 foot knee wall to the ceiling. It is backed up by the wide open space of the entry way of my split foyer. Myself I can't belive how good it sounds there. I have it crossed at 90Hz and sometimes I hear very low bass comming from it. Very full sounding. Also very clear.

Interesting, that's exactly where mine is located. And I've never experienced the problems others have had with imaging. I'm sitting 13 feet from my center channel, how far is your's? I've often thought that this must be part of the reason I don't notice it being so high up. Either that or I'm just not all that sensitive to the placement?

I suppose it could also be a combination of both factors.

Considering how many speakers Axiom must have sold over the years I’m not even sure I would classify it as a “problem.” However, IMO unless you have rabid fanboyism the likes of AV123 or Emotiva (a couple other brands are skirting that territory) that shouts down any less than rave review then it’s been my experience reading forums that negative comments often outweigh positive ones, especially when repeated by those who have zero experience with a product and are often trying to promote their own addenda.


AFAIR he said it got better when he turned MCACC off but it didn’t go away. I’ve had the same experience with Audyssey in two of the three rooms I’ve used the VP150 in where I thought it sounded noticeably better with Audyssey off.



Due to room acoustics placement/seating issues in the two rooms I’ve use my M80s and EP500 in I’ve found I get a better mid-bass punch from my M80s across all my seating than I can get with on EP500. So I usually run them either small crossed at 40Hz (now) or large crossed at 40Hz(last room). Otherwise to get the same level of mid-bass punch across all my seats the lower base is way to strong.

Also I’ve found that a tower center can work well under a screen because if sitting far enough away it’s not localizable below the screen.


In the real world frequencies well below 80Hz are directional, I’ve been knocked on my butt in the direction they were traveling. It’s when you put them in a room they tend to become non directional because of standing waves. However, I’ve found the larger the room lower the frequencies get before being hard to localize. Another reason I like to get the mid-bass punch from my M80s rather than my subwoofer.

I think one of the reason I’m noticing more pequliarities about particular speakers is likely because I spend a lot more time tweaking and trying different things than other people. Many of the things I’ve commented on even concering the VP150 I imagine most people wouldn’t notice even if they were present in there situation. OTOH the hollow tunnel effect I hear in my present room is intense. No A/B comparisons need to hear it.

Cheers,
Dean

Dean, you are getting far to helpfull and clear/concise about your thoughts, it must be time for you to leave this forum

I'm not turning in my man card until he turns in his utility belt.

My 150 is more like 11.5 feet away.

My job does allow me an inordinate (almost criminal) amount of time off at times just wait until I retire and really have to much time on my hands.


Hell if you based my status on my job I wouldn’t even be allowed to have a man card. We can’t even wear tools on our belts have to carry them in tool bags now. They don’t call it the “Scared Force” for nothing.

I'm no expert but I'll add my experience. When I first set up my system and (on my Onkyo NR3007) I watched the Iron Man BR, and set the AVR to minimal processing for the Dolby HD stream. The center channel sounded hollow, and terrible- prompting immediate- "what have I done?" concerns on how much I just spent on my sound system.

I played around with some different settings on the AVR and now I can't believe how seamless my front soundfield is. I get great on and off axis blending between the VP150 and my T60's. The sweet spot for me was the "THX Cinema" mode. I'm not saying an AVR can make a bad speaker good, but I bet poor processing can make a good speaker sound bad. Any of my Direct, or Pure Audio, or minimal processing modes give me poor performance from the center channel.

My experience anyways.

I'm sure it's been said but I'm thousands of posts behind so I'm admittedly skimming but make sure you try it with all of the receivers EQ or other effect choices turned off. One of my most scary experiences was when I somehow turned on the EQ feature and it became set to Flat. Hollow would have been a very good word to describe the sound but for me it was an overall hollowness, not just one speaker but I use that as an example.