Influences, Technology and Design Goals

As owner and designer, I figured that I should give a bit of background on my journey and why OB-ONE should be high on your list of loudspeakers to consider. After working for most of my life as an engineer in the machine tool industry, I finally decided to concentrate on my greatest leisure time hobby as an actual occupation. It is a bit of a bold move during these uncertain times, but I really believe in the products that I am offering, and I really love this hobby.

I have always marveled at the ability to recreate sounds from boxes from the time I was 9 years old, when I got my first tape recorder. As time went on, I listened to a junky, all-in-one, console unit with the tuner, record player, 8 track and cassette tape built in. I listened to my mother’s Frank Sinatra records and my father’s Count Basie and Herb Albert collections. Then, when I was 16 years old, I heard an older friend’s sound system that included two pairs of Bose 901 series 4s stacked on top of each other. It was driven by a high-powered, vintage Kenwood receiver. From then on, I was hooked.

During the years that followed, I did what many audio enthusiasts do; I spent a lot of money and listened to a lot of different audio products. Speakers have always fascinated me the most, primarily because of the mechanical nature and the many varieties.

There are so many ways to propagate sound into the room, each having distinguishing characteristics. From direct radiators, multi-ways, line arrays, coaxials, full rangers, panel speakers, horn loaded, bi-pole and dipole and omnidirectional, I have heard both excellent and mediocre examples of each.

I have determined what stood out the most for me with each type of design. I have ventured to combine the positive characteristics of each into a single design, while mitigating the inevitable compromises. The following sound characteristics and user features were targeted in this design:

1. Power, dynamics, detail, presence and sensitivity leaning towards horns.
2. Image coherence and micro-detail of full-range drivers.
3. Dipole radiation pattern, transient attack leaning towards planar types.
4. Uncongested, open, tight sound of open-baffle bass.
5. Bass control, room adaptation, tone change flexibility and the main system simplification of a built-in powered subwoofer for each speaker.
6. The systems are all in one, ready to go with normal speaker hookups and an AC plug for each. Or, they can become your own customizable speaker with the possibility of upgrading/changing drivers and electronics if ever there is an itch, (for some there probably will be over time).

With open baffles now becoming more popular, many of you that haven’t heard them are probably asking, “why? They don’t look like they would work.”  “Why didn’t they finish that speaker?” Good questions, but there is real science behind the technology that absolutely works. In mid-sized to large living rooms and dedicated sound rooms, there is nothing better. 

One big reason that open baffles are not as popular is the size and space that they can take up in a room during critical listening. With audiophiles, however, this is common for almost all speakers. Most of them put their small monitors or bookshelf speakers on elaborate stands and then place them well away from the walls.  This is regardless of them being traditional forward-radiating box designs. Unlike the larger box designs, the open baffle can be made extremely robust, yet still weigh less and be much more manageable when the customer is “walking” it back to the wall behind it for normal positioning when critical listening is not required. They still sound pretty good, but they will lose the depth, some clarity, and the bass will need adjustment in that close-to-wall position.

Below are two common comments that I have heard regarding the specific technology combinations used in our designs.

1.     Open baffle speakers lack bass.

They can if the wrong drivers are used, and the natural bass roll off on the OB is ignored. By including dedicated bass drivers, with adjustable amplification and EQ, the in-room response below 30 HZ is certainly achievable with our standard 15-inch woofer. This will depend on your room size and listening position, which is true for any speaker.

The great thing about open baffle bass is that the side energy is heavily reduced. This reduces destructive standing waves in typical home listening spaces. It is like buying a great set of bass traps with your speakers. The lack of a box means you don’t hear the box or the port or the early internally reflected bass that comes back through the woofer.

2. Full range and wide range drivers have ragged responses compared to a lot of other more traditional 2-way systems.

This is probably true from a measurement standpoint. These are not going to serve as studio monitors. We wouldn’t want them to. The sound is stark, transparent and present, just like real sounds. It is the most cohesive way for the sound waves to propagate. In addition to being located concentrically, the front to back alignment is dead on. It is the same voice coil. The diaphragm used is super-light, but rigid. Both diaphragms use paper. Although the blends can be vastly different to optimize performance, there is still better synergy and neutrality than combining paper mid-woofers, (or other materials), with plastic or metal tweeters.

With all of the designs, we chose wide range drive units that exhibited the smoothest and most uncolored response for their price ranges. I believe that these units are best when set up to cover the upper ranges on their own. Then the other drive unit should fill in below rather than vise-versa. The ultimate purity is then gained by omitting crossover devices and letting these drivers go completely naked to your amp’s output. If you generally listen at medium-level volumes, in medium-sized rooms, with medium-level bass content, this would be the recommendation. There are times, however, where adding a quality capacitor to serve as a 6dB high pass can save the wide range driver from extra excursion, which reduces mechanical distortions greatly. Why make this driver work hard below 150 hz when this is being handled already by the woofer system? It can be well-worth giving up the last bit of electrical purity to gain the mechanical advantages of reduced excursion.

Are OB-ONE Speakers Right For You?

As much as we would like to think so, our speakers are not for everybody. In the mutual interest of OB-ONE and our customers, we want to review a few simple questions to help you with your purchasing decision. First the bad news, then the good news.

Reasons to avoid: 

1. You have two of the following three conditions: The need for extreme volumes, window rattling bass or to fill a very large room (800 sqft or more). It is all relative, but this is true for any speaker. Large rooms are harder to energize, particularly with low bass. Open baffle bass is less efficient than large reflex or horn systems. Also, as the room size gets larger, standing wave problems tend to reduce. The sidewall cancellation patterns of the open baffle are less beneficial, so the relative punch and sensitivity of other systems can make more sense. If you think you may be pushing it, but choose to buy anyway, then please review our section on set-up, run-in and listening tips below.
2. You definitely favor a really warm, smooth and laid back presentation. These speakers sound alot like horns, with a forward presence that is distinguishable. At the same time there is definite depth of the sound stage and individual performers. If you dislike horns due to the attack and forward nature, then avoid these as well. If you dislike horns because of “honk” coloration effects or lack of depth, then you might love our products.
3. You need to have a wide sweet spot. Some of you will have numerous critical listeners at one time. You want 3 or 4 wide, sitting 10 ft away, getting great center images without jumping to the closest speaker. If so, skip our speakers. The image is generally a bit narrower than average, but certainly has ways to mitigate the effect for a wider sweet spot. You can count on 2 people wide at 10 ft away. As distance increases, so does the width of the sweet spot.
4. You care a lot about technical specifications and measurements. The goals of getting flat response curves, without detrimental breakups are fundamental to have a good start. To what degree these parameters affect the sound is variable. Fast swings and peaks in the response certainly color the sound. Should it be +/- 3dB or less from 20 to 20K? Good luck in a real room without a good sound processor and subwoofers. These speakers are voiced mostly by ear in our listening rooms. Ultimately, when we buy any audio product, we buy the ear of the designer/s, under the budget constraints given. Only you can decide if it sounds right to you. That is why a home trial is so important.

Reasons to buy:

1. You have a typical in home listening space from approximately 300 sq ft to 700 square feet. 
2. You can accommodate a pair of large front profile speakers. They are a part of your furniture aesthetic that will be a focal point of the room.
3. You love the customizable color solutions to fit into your decor like pieces of fine art. We have 5 main colors to start and the ability to match color requests, sometimes for a nominal upcharge.
4. You can handle a bit of assembly to secure the baffle to the base, but then you have a plug and play solution for any type of music.
5. You appreciate a speaker system that really can play a full scale soundstage with only 3-5 watts. The currently designed systems are designed to deliver clean peaks from 103 dB to 108dB at 10 feet.
6. You tend to listen alone or with only a few critical listeners at a time. This would be for most people hooked on this crazy hobby.
7. You want flexibility to change the bass, sometimes for certain songs or albums. It can work wonders to simply change the base level or crossover point for some music and genres.
8. You value a flexible upgrade path for the ultimate in future proofing your speaker investment. There are currently loads of 8-inch drivers that can be experimented with. There will be future amplifier products and I am always on the lookout for eligible woofers. Products that offer advantages will be offered as upgrades as I get further along.
9. Satisfaction guarantee for 30-days after delivery of your speakers. After that time, we offer buy-back options, (for a reasonable used price), for drivers and amps should you decide to upgrade these items in the first year.

Set up, Run in and Listening Tips.

1. Our speakers are best placed (between 30 inches and 60 inches) from the rear wall behind them. The larger your listening room and distance from the speakers, the further you might pull them out. Even a little bit of movement can affect the ability of the bass to lock into the sweet spot. Experiment with this aspect until you are basically satisfied with the detail and tightness of the bass. Moving speaker closer together will increase the “tightness” of the sound. Further apart can increase the perceived low extension.
2. Speaker imaging and tone can be adjusted by towing the speakers in or out. On axis to the ear is the most crisp and present sound. Towing outside the ears a bit will create more rear space but the sound will become a bit more diffused. For the widest sweet spot, adjust the speakers so the center axis of each cross in front of your head, by a couple of feet if necessary.
3. Next proceed to the bass level adjustment. In general, you should not need to adjust the low pass X-over setting much, except to tailor the tone of the bass a bit more beyond what the level adjustment can do. 
4. Determine the safe limits of the speaker as soon as possible. Put on some music that has some demanding bass passages or beats. Gradually increase the volume while paying close attention to three things. A) Full range driver excursion. These are all fragile drivers, relatively speaking. But also they are very sensitive so they need very little power. That said, it should not move much while playing music. Any more than 3 or 4 mm total peak to peak and you are probably getting some distortion. B) Check the woofer excursion (three quarter inch peak to peak is a good max target. C) See if the amplifier flashes it’s clip indicators. Any of these conditions should cause you to back off a bit and take note for the future.