The Smaller Advent Loudspeaker

[Zilch]

The response difference is negligible. Overall power response is also a big part of the sound. I doubt a directional waveguide could match the original sound and reproduce the concert hall balance of the original.

The crashing VHF off axis clearly indicates that the power response is not uniform. This is of little consequence to fans of "concert hall" coloration, which is severely rolled off in the high frequencies. East Coast designers struggled mightily to achieve max dispersion and failed. When Allison finally achieved it, nobody wanted it anymore.

Modern constant directivity waveguides easily accomplish their objective without the concomitant adverse consequences. Omni is dead, and good riddance. The design approach you advocate has long since been repudiated by science, the industry, and the marketplace at large.... :thumbsdn:

And I would say- there's really no way you could say the Unity fullrange speaker in the Mojo test measured as well as the Smaller Advent. That giant hump in the response trumps all the faults in the Advent response.

As you certainly know by now, I am not a huge fan of full-rangers, either.

Thank you for looking, BTW.... :thmbsp:

 

[lumpy]

Ok If you say it Zilch it must be true. I'm done with this.

 

[Dan ʕ•ᴥ•ʔ]

Lumpy, I have to say that despite your statement to the contrary, you are coming off as a bit of a troll. Argument for the sake of argument is not helping to achieve anything. So, let this one go.

 

[RayW]

It's not true because Zilch said so. It's true because it's true. He just happened to be the one saying it.

 

[Dan ʕ•ᴥ•ʔ]

It's not true because Zilch said so. It's true because it's true. He just happened to be the one saying it.

Exactly.

 

[Zilch]

I don't doubt that diffraction effects can be minimized and that perhaps it is worthwhile if there are no other costs. I just doubt that they can be heard. I think they become even less signficant when you are further away from the system as they are averaged out in the reverberant field.

The normalizing reverberant field you postulate does not exist in typical home listening spaces. Study up Toole's new book, Sound Reproduction - Loudspeakers and Rooms.

Ok If you say it Zilch it must be true. I'm done with this.

I hope, instead, it serves as motivation for you to get set up to measure loudspeakers, learn how to do it and what it means, and experience these correlations with listening for yourself, first hand.... :thmbsp:

 

[KentTeffeteller]

Another important thing! These are 4 ohm nominal speakers. Make sure your amplifier or receiver can handle this with aplomb. Henry Kloss forgot more than most loudspeaker designers about good performing bookshelf speakers on a low budget. Many of them are competitive with anything which cost more. After all, he and Edgar Villchur were the fathers of the modern bookshelf speaker system. Otherwise, for full range sound we'd still be using huge cornerhorns.

 

[Brian]

I just love discussions like this. Now, I'll go downstairs and turn on my KLH 27 powering my Smaller Advents and forget all about whether the speakers are good or bad based on little curves and simply listen and enjoy the music allowing my ears to appreciate the sound. In the end this is all it is about and matters.

 

[vinyldavid]

I just love discussions like this. Now, I'll go downstairs and turn on my KLH 27 powering my Smaller Advents and forget all about whether the speakers are good or bad based on little curves and simply listen and enjoy the music allowing my ears to appreciate the sound. In the end this is all it is about and matters.

....and this is all that truly matters....

 

[Dan ʕ•ᴥ•ʔ]

All of you guys who don't care how speakers measure, or understand alignment plots, or how speakers can be improved upon, need to either a.) read up if you are interested in learning, or b.) avoid technical threads altogether.

 

[Zilch]

Thank you, Celt.

If nothing else, it should be apparent that I put some effort into acquiring and presenting this data here.... :yes:

 

[lumpy]

I acknowledge and respect your efforts Zilch.

Thank you, Celt.

If nothing else, it should be apparent that I put some effort into acquiring and presenting this data here.... :yes:

 

[GordonW]

The response difference is negligible. Overall power response is also a big part of the sound. I doubt a directional waveguide could match the original sound and reproduce the concert hall balance of the original.

Had to come back to this a bit.

Why would a directional speaker have any inherent difficulty in maintaining balance? In fact, if it's UNIFORMLY directional (i.e, has uniform balance within it's "cone of dispersion" throughout the frequency range), it should have VERY even power balance throughout the room. Yes, some places in the room will be LOUDER (in a broad-band sense) than others (depending on angle), but the tonal balance (i.e, WRT frequency) should NOT change appreciably.

In fact, the tonal balance from a (uniformly) directional speaker will usually change significantly LESS than with an omnidirectional speaker, in different room locations... because directional speakers don't have NEARLY the problem of wall-reflection cancellations. If you don't spray sound at the wall, floor and ceiling, it won't come back to cause you problems!

In essence... we're starting to find that there is an optimal range of dispersion out there... probably somewhere in the 90 degree range (45 degrees in every direction from center line, maybe skewed a little wider in the horizontal axis and a little narrower on the vertical axis), or thereabouts. This avoids the "painting of the side wall" problems of truly omnidirectional speakers... which pays of GREATLY in better perceived transient response, more uniform power balance distribution in the room with respect to frequency, and even better perceived imaging in many cases.

This is, with the obvious caveat of sometimes having some beaminess in the last octave, one reason why dual-concentric speakers like Tannoys have such good perceived imaging and tonal balance wherever you are in the room... they set themselves up, by having controlled dispersion where it counts, to NOT have so many issues with reflections, cancellations and the like. No speaker design is perfect... but IME, well designed waveguides and dual concentrics seem to have an edge in this department...

Regards,
Gordon.

 

[packrat]

Zilch,
Weren't you going to mount the 6x6" waveguide in this? I want to do just that, but the 6x12 won't fit and I don't know where to get the 6x6 I've seen show up in other projects.

 

[Zilch]

Zilch,
Weren't you going to mount the 6x6" waveguide in this? I want to do just that, but the 6x12 won't fit and I don't know where to get the 6x6 I've seen show up in other projects.

Yes, Part #364914-001, $6 from JBL Pro Parts:

http://www.jblproservice.com/forms/parts_order1.html

Measurements confirm what many here already knew -- these have nearly as good bass as the Large Advents.... :thmbsp:

 

[tarior]

Measurements confirm what many here already knew -- these have nearly as good bass as the Large Advents.... :thmbsp:

.....and better mids.

 

[packrat]

Yes, Part #364914-001, $6 from JBL Pro Parts:

http://www.jblproservice.com/forms/parts_order1.html

Measurements confirm what many here already knew -- these have nearly as good bass as the Large Advents.... :thmbsp:

OK, but I'm not sure JBL pro will deal with me. I'll try a local pro shop, but I expect a $6US part to become a $30CAN part. Is there anything at PE that will work?

 

[Zilch]

OK, but I'm not sure JBL pro will deal with me. I'll try a local pro shop, but I expect a $6US part to become a $30CAN part. Is there anything at PE that will work?

We used a 7" elliptical from PE for upgrading KLH-17, but the filter had to be tweaked a bit. Same's true for the 6" JBL, but nobody's worked out the detail yet.

You're right that JBL Pro won't ship to Canada, but any of your buds in the US here on AK can reship to you without difficulty as they are diminutive waveguides.... :yes:

 

[saltwater]

So did you actually do this? I got a pair coming, just not sure if the tweeters are dead yet.... any pictures of what they look like after the waveguide was installed?

 

[Zilch]

So did you actually do this? I got a pair coming, just not sure if the tweeters are dead yet.... any pictures of what they look like after the waveguide was installed?

Nothing more as yet, but I may cut in the waveguides tomorrow so y'all can get a look, at least.

They're presently mounted in Boston A60s, but I've pretty much decided to abandon those in favor of these Advents and KLH-6s, using their stock woofers. To make A60s happen, I had to install JBL 116H woofers, the same formula as AR4x, and I have plenty of those around here to work with now, instead.... :yes: