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Posted By: snm69 Center channel conundrum - 04/23/10 02:14 PM
Guys, I'm brand new here, so if this is answered elsewhere, please point me in the right direction. I'm also a novice on speakers.

I am about to buy a pair of in-wall/on-wall M22s as front L&Rs, a pair of iwow M3's for the rears of a 5.1 system. I am struggling with the center.

I have read many, many reviews and opinions on the VP100 and 150 centers and although 90% are excellent, a few people say they emphasizes "s" sounds and pop the "p" sounds (and I dislike that trait). Is that due to the frequency response at all, and would an M22 center (it would have to be an in-wall M22) sound any better?...I know what sounds "better" is a very personal thing. Or would LCR iwow M3s do a good job as an alternative?

My room is "U" shaped (i.e.one side is open to our kitchen) and 15 feet by 12 feet in area and 9 feet high. Typical L'shaped sofa and a large picture window on the wall opposite the LCD TV. We watch TV and I love to listen to music, so I am really leaning towards to good system musically, with movies as a secondary requirement.

As for the sub, I am leaning towards an EP175. The only sub I have heard is an Orb Super 80 which I am testing (the orb system is about to go back - I don't like the sound, which seems to be missing the whole mid-range). But the Orb has this BASH digital processing and the EP75 does not. If anyone can explain what that's all about, I would appreciate it.

Thanks ever so!

Cheers!
Posted By: BobKay Re: Center channel conundrum - 04/23/10 02:44 PM
SNM: Do hang out here, or check back regularly for an answer to your question. There are lots of forum members who check in daily and will get to your question in detail soon. I've watched them in action and the detail of their knowledge can be scary. Their willingness to share is awesome.

You won't be disappointed. Welcome!
Posted By: CatBrat Re: Center channel conundrum - 04/23/10 02:53 PM
I'll add my 2 cents worth and I'm sure others will chime in also.

I currently have on-wall M22's with an in-wall/on-wall VP100. I have an EP175v2 on order. (I also have a pair of bookcase M22's in storage)

After installing the in-wall/on-wall VP100, I ordered in-wall/on-wall M22's, cut the hole for one side, then discovered that I had obstacles behind the drywall that wouldn't allow me to mount them. At this point in time, the on-wall versions of the M22's were in early stages of production, so I ordered them, which I also have installed.

As to sound quality, all 3 of the versions sound excellent with differences. There is a lot of bass that you wouldn't expect coming out of the bookcase M22's. I listened to the in-wall/on-wall M22's before sending them back and they sounded slightly better than the on-wall M22's. Since I haven't received the EP175 yet, I can't vouch for how they sound with the on-wall version.

The timbre match between the bookcase M22 and the in-wall/on-wall VP100 is not good, but with the on-wall version instead it is a good match.

My room is 1800 sq. ft. with 2 openings. If yours is more than 2000 sq. ft., you might want to go with an EP350 instead, but you can always try the EP175 and see if your happy with it. Just don't expect tremendous bass emphasis out of it. I expect just enough to enhance the on-walls that I have. The reason I chose the EP175 is because of the smaller size. It's going to be a piece of furniture sticking out just under the VP100.

Oh, I forgot to address the s and p sounds. The only time I've heard that is when I turn up the treble to around +4 or so in the AVR, which is too much treble anyway, so no problem there.
Posted By: snazzed Re: Center channel conundrum - 04/23/10 03:27 PM
Hey SnM69... nice name!

I can't speak to the Centre Channel question so I'll go right to the Subwoofer...

I would think the Orb Amp wouldn't be too much more efficient than the 175 and here's my speculation:

Your Basic Amp types are as follows:
- Class A
- Class B
- Class A/B Switching
- Class C (not used in Audio)
- Class D (A/B Switching with digital processing)

Here's the interesting part... BASH stands for: Bridged Amp Switching Hybrid and is a Trademark name. Now, I'm no Amp expert but I believe this means its a Class A and Class B Amp that Switches between the 2. I *think* that a BASH amp is essentially the same as an AB-Switching Amp, but the name BASH is trademarked so not everyone can use it.

Class D is also an A/B switching amp but uses Digital processes so it can switch much faster than a traditional A/B Switching.

Now the EP175 doesn't specify at all the type of Amplifier it sports, and perhaps and Axiomite can help out here... but I would be surprised if it was a straight Class A or a Class B amp. If it was a Class D, I imagine they would brag about it... I'm *guessing* its a Class A/B Switching, which I *think* is the same thing as a BASH Amp, but they can't use the name BASH.

It is also possible that the "BASH with Digital Processing" is a Class D Amp (because it has digital processing) but they still wanted to use their BASH Trademark.

Summary:
I have a lot of qualifiers in here so until I get an authoratative answer, consider me to be talking out of my ass.

As usual, correct me if I'm wrong please \:\)

snazzed
Posted By: Adrian Re: Center channel conundrum - 04/23/10 04:40 PM
In regards to "s" sounds(sibilance), and this is generalizing for ALL speaker manufacturers, source marerial is quite often the culprit and not the speaker. I have noticed this on my VP150. If a speaker is sibilant, it's going to be that way on all material, not just certain recordings which I have found.
Posted By: snm69 Re: Center channel conundrum - 04/23/10 05:26 PM
Thanks very much. Really helpful.

And I never even thought about my name that way! It's actually my initials and year I was born. May be someone deeper than me can look into that and psycho-analize me!
Posted By: jakewash Re: Center channel conundrum - 04/23/10 05:59 PM
JP, your next client is in the waiting room..........


So far as the sibilance, you will notice it on the M22's as well as the VP series, if it is there in the recordings you will hear it. The M3's display less of this trait, so if you really dislike hearing that sibilant "S' you might want to steer clear of the M22s/VP series and use M3s across the front.
Posted By: BobKay Re: Center channel conundrum - 04/23/10 07:17 PM
snm. I told ya. It's sort of like having "OnStar" for a/v.
Hmm? 1969? You were a baby and I was a hippie.
Posted By: alan Re: Center channel conundrum - 04/23/10 08:42 PM
Hi snazzed,

Thanks for contributing but there are some mixed-up statements in your explanation of amplifier classes.

While it's true that the output transistors switch on and off in a Class B analog amplifier, the term "switching amplifier" is only applied to Class D digital amplifiers that use high-frequency switching to modulate the output stage.

A Class A/B analog amplifier isn't a switching amplifier because a small current is constantly left on through the output transistors to prevent distortion when the output devices alternately amplify the opposite sides of the waveform.

Here is a guide I wrote some time ago for the AudioFile newsletter that defines the various amplifier classes:

Class A designs have current constantly flowing through the output transistors even if there is no incoming audio signal, so the output transistors are always on. This type of amplifier has the lowest distortion of any but it’s extremely wasteful and inefficient, dissipating 80% of its power in heat with an efficiency of only 20%.

Class B amplifiers use output transistors that switch on and off, with one device amplifying the positive portion of the waveform, the other device the negative part. If there is no incoming audio signal, then no current flows through the output transistors. Consequently, Class B amplifiers are much more efficient (about 50% to 70%) than Class A designs, however there may be non-linear distortions that occur when one set of transistors switch off and the other set switches on.

Class A/B amplifiers combine the virtues of Class A and Class B designs by having one output device stay on a bit longer, while the other device takes over amplifying the other half of the audio waveform. In other words, there is a small current on at all times in the crossover portion of each output device, which eliminates the potential switching distortion of a pure Class B design. Efficiency of a Class A/B amp is still about 50%.

Class D amplifiers, although there are a number of different design variations, are essentially switching amplifiers or Pulse Width Modulator (PWM) designs. The incoming analog audio signal is used to modulate a very high frequency PWM carrier that works the output stage either fully on or off. This ultra-high frequency carrier must be removed from the audio output with a reconstruction filter so that no ultra-high frequency switching components remain to corrupt the audio signals. As previously mentioned, Class D designs are extremely efficient, typically in the range of 85% to 90% or more.

The BASH amplifiers, originally a Toronto-based company now owned by Sonavox, are a design unto themselves, but are basically a different type of Class D switching amplifier. Axiom used BASH subwoofer amps in the late 90s and into the 2000's.

The current EP175 subwoofer now uses our own Axiom-built amplifier which is a Class D switching amplifier with an analog power supply that is unique (most Class D sub amplifiers use high-frequency switching power supplies).

BASH amplifiers continue to be used by many other subwoofer companies.

Regards,
Posted By: Potatohead Re: Center channel conundrum - 04/23/10 09:11 PM
This whole Sssss thing with the VP150 I find a little odd. I have one (W150), and W22's and I just don't really notice it at all, even if I listen for it. Obviously there is an Sss sound but I don't notice it to be any more pronounced than when speaking to someone normally in person.

If you sit more than 12' from the speaker, buy the 150, otherwise the 100 is probably fine... At least this is what Axiom told to me when I bought my setup. For the $120 or whatever if you watch movies a lot I would (and did) buy the 150.
Posted By: snazzed Re: Center channel conundrum - 04/23/10 09:42 PM
 Originally Posted By: alan
Hi snazzed,

Thanks for contributing but there are some mixed-up statements in your explanation of amplifier classes.


lol! I'll try not to take that personally!

Yeah, I know that I don't know too much about Amps... that was about as much as I could figure out when I did a bunch of research about 6 months ago.

Seems to be a regular technique of mine... find people who know what they are talking about and say, "this is how I think it is..." and then learn when they tell me how I'm wrong.

It sucks, however, when I say "this is how I think it is..." and nobody knows any better. Of course I then assume I'm right. \:\)

I'm just glad I repeatedly said, "this is what I think and I may be wrong"

humbly
snazzed
Posted By: alan Re: Center channel conundrum - 04/23/10 10:05 PM
Hi again,

Certainly don't take it personally. It's really complicated and I have to ask our chief engineer every time I talk about amplifier classes. There is one more class I forgot about, fairly rare, but used by NAD in their stereo amps, a Class H (or is it G--I've just had my late afternoon glass of red wine so I'm too lazy to go look it up). The NAD amps have quite modest continuous rated power output, about 50 watts per channel, but when musical dynamic peaks come along, a second set of voltage rails on the power supply momentarily switch in to generate up to twice as much power, 100 watts in this case, equivalent to 3 dB of headroom, to avoid clipping the peak signal.

Cheers,

Alan
Posted By: snm69 Re: Center channel conundrum - 04/23/10 10:13 PM
You guys are awesome. Thanks for the input so far and keep it coming.

I have just ordered iwow M22s, iwow M3s and an iwow Vp100. I think the VP100 will do the job based on your feedback, but if it doesn't, the 150 is in the wings. I can't wait for it all to arrive. I'll be tracking it by the hour across the US from Canada!
Posted By: Glitchy Re: Center channel conundrum - 04/23/10 10:19 PM
 Originally Posted By: snm69
You guys are awesome. Thanks for the input so far and keep it coming.

I have just ordered iwow M22s, iwow M3s and an iwow Vp100. I think the VP100 will do the job based on your feedback, but if it doesn't, the 150 is in the wings. I can't wait for it all to arrive. I'll be tracking it by the hour across the US from Canada!


I think I may have the answer to your inwall on wall V100/V150 conundrum.....

http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showgallery&Number=294434
Posted By: ClubNeon Re: Center channel conundrum - 04/23/10 10:43 PM
 Originally Posted By: alan
There is one more class I forgot about, fairly rare, but used by NAD in their stereo amps, a Class H (or is it G--I've just had my late afternoon glass of red wine so I'm too lazy to go look it up). The NAD amps have quite modest continuous rated power output, about 50 watts per channel, but when musical dynamic peaks come along, a second set of voltage rails on the power supply momentarily switch in to generate up to twice as much power, 100 watts in this case, equivalent to 3 dB of headroom, to avoid clipping the peak signal.

Outlaw's M2200s are also Class G. It's a kinda neat design, considering that most listening is done with only and handful of Watts.

The difference between G and H is that G has two rails of fixed voltage, it just steps up to the higher one when the lower can't deliver the needed power. With H the second rail is variable, and follows the signal providing only what's needed. H is even more efficient, but has slightly higher distortion.
Posted By: Micah Re: Center channel conundrum - 04/23/10 10:54 PM
I've never had a problem with sibilance out of my 150. That said if you're looking for the ultimate center channel with that system, most people will tell you the best choice is to use the same center as the mains you're using.

So three M22's might be the best set-up for you if you can accomodate it under your screen.
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