The Bose Spiral Design?

One does not have to be very far away from any speaker. Ever used headphones? That much is BS. Bose subs are barely worthy of the name.
http://www.intellexual.net/bose.html

I know we have a million Bose bashing posts and I don't mean to add to it. I can't speak to the specifics of your particular question. However, I've heard dozens of Bose setups and I've not heard them excel at anything. Most honest, professional reviewers and people on this forum, whose opinions I take seriously would tend to agree. That, to me, should somewhat answer your question.

Maybe she was thinking of some type of transmission line system, a legitimate design still used today (it's pretty rare though because they're tricky to work with). They can generate some seriously deep bass but tend to be rather large.

As with so many things. there is a grain of truth there, but there is also a preponderance of total nonsense.

First of all, the idea that any Bose product has great low end response is factually incorrect; they do not. They are very non-linear with high distortion at most sound levels.

They are basically a cross between a transmission line design and a horn design, but they simply are poor designs that don't work well because they are cheaply implemented and use flawed designs.

For some related designs that really DO have excellent performance, you can look at the famous Klipschhorn corner-horn design and the Gallo Acoustics CL-3 and CL-4 designs.

Te Klipschhorn has been around for over 60 years and has remained essentially unchanged; it has its limitations, but within those limitations it is an amazingly good design.

The Gallo Acoustics CL-3 and CL-4, however, are relatively new and break ground in two areas. First, they use a novel loaded transmission-line approach that makes the speaker put out low-distortion low bass that is what one would expect from a speaker 2 to 3 times larger. Second, the performance and loading of the ultra-light carbon-fiber low-end drivers combined with a unique tweeter configuration allows them to have NO CROSSOVER network, all of which makes the sound quality quite amazing.

For further information on this novel Gallo design, you will be interested in reading the article on the CL-3 in last month's issue of The Absolute Sound. Good stuff!


Edited by commsysman - 7/4/12 at 5:09pm

I'm not aware of Bose even making this claim. Where she got that from, who knows?

I do think she should give the Bose marketing team a call, they may have a job for her.

If you look at a cutaway of a wave radio you can see a slight resemblance, so that's probably the source. But going back to the original post, upon reading it again: That statement is a retelling of the wave propagation myth, so OP, ask for a refund on your tuition, your teacher was clueless and should not have been in front of that class.
Edited by Bill Fitzmaurice - 7/4/12 at 7:20pm

I guess that is my point... it appears that she made it up!

Spiral design huh? That must be how they get lows they are know for

Here's the cutaway of a real 12" sub from Genelec that uses a design which is similar to the one you are talking about:



Functionally this is pretty much just a flared, slotted port neatly built into the structure.

This should clear everything up! Can any audio engineers please translate this for me?

http://www.youtube.com/watch?v=C-AyALSl-I0&feature=related

The wave radio speaker? It's a transmission line. The 26 inch long duct will have a 1/4 wavelength resonance at 130Hz, which makes it better than the average table radio, but it's still a $200 product that sells for $600. As for the 'Bose technology' 1/4 wavelength devices have existed almost as long as speakers have; the first major proponent of them was Voigt, circa 1934.

How does sound from a small driver, traveling through a 26 inch tube make it sound fuller, deeper and like a larger driver?

As explained above, via reinforcing the front wave with a 1/4 wavelength resonant pipe on the backwave. What Bose doesn't say is that the result is only better than using the same driver in a small sealed cab. It's not necessarily any better, or for that matter as good, as a well engineered bass reflex alignment.

I see this site linked to quite a bit on www.diyaudio.com:

http://t-linespeakers.org/

Even Radio Shack tried their hand at this system: Catalog for '81 - page 24, listed as a "tuned labyrinth"

Except it wasn't a labyrinth, more like a reflex with a long port. Acoustic labyrinths were 1/4 wavelength designs that really looked like a labyrinth, with a small rear chamber, and a labyrinthine folded duct on the order of six to eight feet long.
http://electronic-terms-dictionary.info/index.php/term/Electronic+terms+dictionary,Acoustic+labyrinth
Edited by Bill Fitzmaurice - 2/17/13 at 6:45am

^ that's why I used the word "tried".

I doubt so much 'tried' as they used a term that they didn't understand to apply to something entirely different. It wouldn't be the first time. Karlson called his 6th order series tuned bandpass cab a horn, though it was anything but. He could be forgiven since in the 1950s the concepts behind 6th order series tuned bandpasses were some 20 years distant. Not knowing what it was he'd devised since the baffle resembled a horn that's what he called it.
Going back to the Stromberg-Carlson acoustic labyrinth, it was an obvious precursor to the Bose wave design, and should have voided any patent application on that concept by Bose. But when you charge three times what your product is worth you can afford to hire a legion of patent attorneys to bamboozle patent office examiners into granting patents that they shouldn't, just as you can run full page ads in every newspaper and magazine to bamboozle consumers into buying it.

Hello,

1st post, please don't hit me!

What I'm interested in is not the "great sound" of the wave but the amount of bass you can get from such a small box, as I'd like to build an ultra portable amplifier for a bass guitar. These speakers are like 3 inches, so to me that's still quite impressive bass.

My requirements are:
- Small size, preferably light but I prefer small to light
- At least 50 watts (100-150 would be better) as I have to compete with a drum
- High fidelity is not a must, high frequencies aren't really needed, but I don't want a completely lame sound either if possible

Anyone could help me with these questions?

1- Is it possible to get the Bose speakers alone without the box, or something similar/better? If so, where?
2- Since I don't need stereo, could I even cut the size/weight in half?
3- I probably need more power. The owner manual states a power consumption of 50 watts, so I guess the speakers are probably around 10-20 watts each. (http://products.bose.com/pdf/customer_service/owners/wrv3_guide.pdf). If no small driver with higher power and low frequencies are available, would you recommend an isobaric pair driving a transmission line / labyrinth in the back? can many drivers share the same labyrinth?
4- Anything else you recommend? Please don't hesitate to go wild!

Best regards

Phil Ranger

PS: While I'm quite good with electronics, designing crossovers, etc. I'm not that knowledgeable in acoustics. Thanks for keeping it simple!

Don't bother, it won't work. If it did you'd be able to buy one at G-C.

.

I'm wondering if an isobaric or a labyrinth would be better. And for Bill:

http://www.orangeamps.com/products/bass-guitar-amp-combos/terror-series/terror-bass-500-bass-amp-head/

I don't need 500 Watts with an ultra deep sound, so I'm looking for alternatives. I'm willing to build but don't wanna destroy my 401k

Best regards

Phil

Sorry for the double post. Damn facebook!

No. You're still best off with a bass reflex cab.
I can't recommend anything I don't have first hand experience with. Try bass guitar forums.

I miss metal tapes! And TRS-80 computers!!

Irish I sure don't miss giving my name, number, location history, mothers maiden name and what grade school I went to just to buy a four pack of batteries.

I want to design a very small case with interesting bass volume/power. I understand it won't be the most faithful nor the widest frequency range.

The problem with bass guitar forums is that there is quite a lot of information on playing technique but the rest is mostly " a new device is out" followed by everyone saying how there favorite brand is better than the others, without any technical data or other valid arguments. Since I'm not looking for product hype and this forum has a whole section about speakers, I was hoping some members could have knowledge that could help me. My bad?

Phil

Making powerful bass means moving a lot of air. As far as I can tell, that is really tough to do with very small devices.

Google Hoffman's Iron Law. What you want to do can't be done. I recommended them for opinions on amps. As far as speakers go, if you want to learn about them you should go to a forum dedicated to speaker building, like the DIY section here, or this:

http://techtalk.parts-express.com/

Except in the Bose wave system?


I'll try it. Thanks!

Phil