Is there a point to the shape of the baffles for Carver Amazings?

Jstas

I was looking at my Amazings last night and the trapezoidal shape of them. I got to wondering if the odd and ungainly shape is absolutely necessary?

I mean, I've seen people set them up with the ribbons on the outside and claim it improves imaging. So I doubt it has anything to do with placement. If that's the case, what's the reason for the extra material?

There is the possibility that the extra mass reduces vibrations and resonances. However, the large baffles aren't much more than 1 inch thick MDF covered in acrylic (or a wood veneer if you have a wood finish). Extra mass can be added in other ways that would be much less intrusive.

If all of that's the case, it makes me wonder if it'd be possible to build new baffles for them and lose the extra material that hangs off to the sides and makes them so much wider than the top.

Any clues?

RuSsMaN

"For example, it so happens that the asymmetry of the front baffle is important for smoothing out the bass response of any dipole radiator. A rectangular baffle would have worked, but not as well as an irregular one."

http://www.stereophile.com/floorloudspeakers/290carver/

Face

Diffraction and baffle step.

Changing the baffle would necessitate changes in the crossover.

Systems

RuSsMaN wrote: »

"For example, it so happens that the asymmetry of the front baffle is important for smoothing out the bass response of any dipole radiator. A rectangular baffle would have worked, but not as well as an irregular one."

To expound abit,being a dipole(open baffle) there will be cancellation occuring at low frequencies because the front and back wave of the woofers output will be out phase.If the baffle were square the path length from front to back would be the same so cancellation would be more consentrated at certain frequuencies related to the baffles width.Making the baffle dimensions disimilar will result in different front to back pathlengths thus spreading out the frequency of cancellation somewhat.

rallyshark

Good question, and good description! I've always wondered how open baffle dipole type speakers could have any bass at all?

Systems

rallyshark wrote: »

I've always wondered how open baffle dipole type speakers could have any bass at all?

Dipoles usually need some electronic assistance in the form of EQ/boost to restore some of the lost output at the bottom end.Wider baffles help because this will push the out of phase cancellation to lower frequencies.Aswell to achieve high levels of low bass dipoles require drivers with lots of surface area/ volume displacement.

Face

http://www.musicanddesign.com/Dipoles_and_open_baffles.html

rallyshark

VERY interesting! Time to get my learn on:) Thanks!

dorokusai

I always thought the bass response from the Carver was unimpressive given 8 12" woofers.

thuffman03

dorokusai wrote: »

I always thought the bass response from the Carver was unimpressive given 8 12" woofers.

Do you know what amps were used to drive them.

I have found that they do like lots of power. With more power comes better base from them. Plus there are several versions of the Amazing Plats. The MKIV was the best.

cnh

I have yet to hear a pair of these. They come up a lot on this site....but I've also wondered about the odd shape....so thanks to all of the above for so 'clear' an explanation of the dipolar problems involved!

cnh

Jstas

The Amazings, for their size, are not powerhouse speakers. They are big and with eight 12" pistons pumping away and ribbons that reach all the way down to 25 Hz themselves, you'd think they would have more output.

BUT! The woofers are not actually "sub" woofers but just woofers. They dig down to something like 17 Hz I believe it is but that is at a rapidly dropping off -6 dB. So even though it's hitting that low, it's barely audible unless you are driving the living hell out of them.

But, because they are dipoles in an open or free-air design, they only reach about 120-125 dB in total even with a substation worth of power strapped up to them. Having 5 or 6 drivers each (depending on model) for a total of 10-12 active drivers makes them fairly insensitive and a heavy, complex load to drive. Because of that, the woofers are very lightweight so they are easier to drive. That doesn't make for big bass because teh drivers can't handle the power without cone deflection. On that same note, if you are pushing 1200 watts of power to each speaker, that seems like a big pile of power. Now divide 1200 by 6 and now you only have 200 watts of power per driver and that's not nearly as impressive. So there is alot of stuff working against the big sound.

Because of all of that, they tend to be finesse speakers which seem to excel at a pretty flat response over a very large response curve. They like power but they seem to be forgiving with gear. Even average stuff like an Onkyo pre-amp and amplifier will sound quite good with a set of Amazings.

As far as how they sound, they live up to their name. Forget soundstage and depth and such, it's there and placement matters due to the dipole design. But I say to for get that soundstage stuff because even if they aren't set up exactly right, the sound coming from them is quite impressive. They can have a "magic" similar to the SDAs when set up correctly but, this is hard to explain, the sound is complete. The ribbons have very few valleys in the response curve and even if they do, they are shallow. On many speakers, even the high end stuff, with multiple drivers for each section (high, mid low) of the response curve, you can hear the lack of info in the programming. I know, sound stupid but, what you don't know you're missing you don't know you're missing. It's subtle but it's there. For an example of what I mean, refer to Bose vs. damn near every other speaker out there. Bose stuff misses info that other stuff produces.

Well, the Carvers can show where other stuff is missing info because the Carvers miss next to nothing. It is a complete sound coming from them. When you get the sweet spot just right, it's surreal how complete it is.

Mine aren't set right because of my space constraints. But they will get room to breathe soon. If you really want to hear them set right, buddy up to Mr. Grand and take a gander at The Truth. If you're nice, he'll let you sit in the sweet spot! You'll forget about everything else and want to duplicate that setup as close as you can. I can honestly say that the only sound the comes close IMO is that from AR9's or the big SDAs. Beyond that, you have to tread in to the range of the likes of Sonus Faber to get a speaker that has as complete of a reproduction of track information as the Amazings.

Then again, if you want to hear what kind of bass the Amazings are capable of, put on a track you like with heavy bass. Turn it up to a reasonable level and then...leave the room and close the door behind you. You will be surprised at the level of low-level frequencies that are emanating through the house. The Amazings like space. The more the better. Reflections are not their friends. So wide open spaces where the dipole effect has room to expand and the low level frequencies can expand within the listening area instead of traveling through walls and outside the listening area is an ideal listening situation.

dorokusai

thuffman03 wrote: »

Do you know what amps were used to drive them.

I have found that they do like lots of power. With more power comes better base from them. Plus there are several versions of the Amazing Plats. The MKIV was the best.

I never have power issues.