tonygeno,
It is quite apparent you still do not understand how pink noise works and why i'm telling you this measurement you took is not all that relevant to the use of the centre channel for realistic sound reproduction (music and movies). Pink noise does NOT reproduce the same SPL through different sound ranges by its nature (see the
link again with more technical info about pink noise). Since the VP150 has 2 different driver types with crossovers for different frequencies it is EXPECTED that the dB will vary from high to low frequency drivers whether it is an Axiom speaker or not.
To reiterate what Alan had posted on the subject:
"ALL speakers at the front of a room produce comb filtering and uneven response as a result. It's yet a further liability of stereo listening and is quite audible using pink noise as a test signal.... but while it's audible with pink noise, it's not a significant factor that seriously undermines our enjoyment of music, movies, or even stereo playback, nor is it identifiable using music as a test signal."
In reply to:
Now, maybe you'll tell me this is inaudible...I heard it.
With pink noise?
YES. IT CAN BE AUDIBLE WITH PINK NOISE.
You never measured this 'suckout' with music playing did you? Your arguments so far have only centered around this pink noise measurement.
These other centre channels you listed (and stated as having done the exact? same measurements with although you no longer own these other units to be sure) were the Axiom M2 and the NHT M5 (and also a CSW?). Unless there are other units you have not listed, the context of this message will refer to the first two speakers as centre channels in comparison.
The M5 has a WTW configuration and its "suckout" would be in the middle location while using pink noise. Not to the left or right.
The M2 would have a vertical "suckout" with pink noise, however its left and right off axis dropoff would probably be higher than the VP150 since width does make a difference the more you move off axis. Now you even stated that the M2 and the NHT both had a 1dB drop in sound as well which only proves they also have this 'suckout' effect although apparently less (2dB being a rather insignificant difference at this point).
Then you also mentioned you turned the M2 on its side. And yet you did not measure a difference in SPL as you moved from the left to the right even though the driver config goes from woofer to tweeter? This i definitely do not believe. Turning the M2 on its side takes its vertical pink noise suckout to the horizontal plane. That would only follow the laws of physics. What you never measured before left to right with the M2 vertically will be measured left to right if it is placed horizonatally.
Now as i recall, your original post had complained of a problem with a 2dB drop in sound. By the second time you spoke of this info the dB "suckout" had somehow increased to 4dB and by the last time you mentioned it the dB drop was up to 5. Is there perhaps some mild exaggeration on your behalf regarding this whole "problem"? Almost every other poster found the same 2dB drop with the VP150 (as did i) when using pink noise. I have measured no drop at all when using music. This is typical.
As for this statement:
"why many manufacturers such as NHT, CSW, Revel, Rocket, Infinity, Ariel, von Schweickert, etc include proper mid-ranges above or below the tweeters in their high end center channel. They do it, so you won't get these measurement anomalies that you get with the WTW or TWWWT arrangements"
Proper midranges?
Shall i quote Alan's statement yet again on how ALL speakers have....?
In reply to:
You can search Stereophile Guide on-line and see legion WTW centers with this suckout.
With pink noise?
YES. IT OCCURS WITH ALL SPEAKERS.
Shall i quote Alan again here?
Are we seeing a pattern yet?
