Disclosure: Response Audio is a dealer for this product offering both finished product as well as custom built crossovers for those building their own speakers. As most already know, the OB-7 is available as a kit and there are many who are building their own from start to finish and have asked me to post my findings so they have an idea of what to expect. I am sure they will post their findings when the time comes and we can then compare notes at that time. Please keep in mind that these are only my personal findings and obviously may not reflect the opinions of others. My opinion is just that....an opinion.
With less than 20 hours on the speakers, these are only quick initial impresions as it is obvious the speakers are not yet broken in and things will get even better in time.
The Initial Process:
After building the OB-7 Deluxe speakers from the flat pack offerings by Denny, I now have about 15-16 hours on the speakers. Keep in mind my speakers have the upgraded M130X woofers. My crossovers are built using components as supplied by Danny of GR Research. There are no alterations other than the user adjustable Bass Management System and Tweeter level Control. At time of this writing, I do not even have any of the Platinum Teflon bypass capacitors installed. This will be done a bit later (probably tomorrow) where bypasses will be installed in the Midrange and Tweeter circuits.
Initial setup
The first hour was brutal. When I started up the first track, the system sounded like there was a miswiring of the bass drivers or incorrect wiring of the crossover. The sounds was disjointed and thin from the midrange up. I contribute this to being a fresh pair of speakers with no initial burn-in on any of the drivers of crossover components. When we purchase manufactured loudspeakers, the manufacturer will test the speakers which puts time on them before going out the door. Even we do this with our finished products. This is why you never experience this initial mess with retail products. Consider yourself lucky. I mention this because I know there will be many people reading this that are building their own speakers and I want to give you a heads up so you won't go taking your speakers apart looking for mistakes in the wiring.
After confirming everything was wired correctly and working properly I fed the speakers a burn-in track from Stereophile's Test CD 3 for about an hour at low listening levels. Who wants to listen to that for an hour. After this quick burn-in I sat down for a quick listen and found things were starting to sound better. Not perfect yet but the initial nastiness was gone and coherency was starting to set in. At this time, I started feeding the CD player various recordings, cranked them up a bit and went about my business at the work benches for a few more hours.
The Evaluation
After several hours of heavy pounding I thought is was time to start listening. I'm starting to go through many of the reference recordings I have used for some time and very familiar with (see list below). I found myself getting drawn further into the sound of these speakers.
Let's start at the bottom The OB-7's are obviously not to be mistaken for full range speakers and some may even find a subwoofer to be required. Not me. While they do not reach down into the lowest registers, there is plenty of bass present. If I had to guess, I would say I was hearing linear output into the upper mid 40's. In my large room I still found it necessary to attenuate the bass output quite a bit with the BMS. I was able to dial things in for a smooth response from the lowest to highest frequency extremes.
I am one that is willing to sacrifice a few Hz's for speed and articulation. I like my bass to be clean, fast and tight and I want to be able to feel the lower frequencies' impact in my chest while at the same time, hearing all the subtleties that any given recording has to offer. This is exactly what the OB-7's offer with it's 5.25" drivers in a sealed enclosure. No bloat, no bloom just a fast clean response. I don't think I have ever run across a subwoofer that would be able to keep up with the OB-7's 5.25" drivers (I will admit I have not heard a lot of subs) so I am not going to ruin what I am hearing just to get a few more octaves.
Since most of a speaker's magic is in the midrange, I will save that for last and move onto the upper end. Planar tweeters can be difficult to work with at times. I have heard many bad examples of planar tweeters integrated into a system with cone drivers. The tweeter on the OB-7 is among the smoothest I have heard. My original intentions was to build a TLC (tweeter level control) into the crossovers to help tame down the planar tweeter. After spending the last 16 hours with these speakers, I am not so sure I need to do this. I am trying my hardest to hear the crossover point between the midrange drivers and tweeters but if I didn't know better, I would say there is only one driver producing these frequencies. Single driver designs have nothing over the OB-7's upper panel in regard to point source imaging and presentation. The integration is perfect.
The tweeter is very smooth and balanced. I was expecting a bit of harshness at it's extremes but have experienced nothing like this with any of the recordings I have thrown at these speakers. My favorite test for this is Norah Jones - Feels Like Home disc. Her voice in this recording has the potential to come across very harsh at times on many systems I have heard in the past. With the OB-7's, she was sounding smooth and seductive without any loss of detail.
Let's move on to the midrange. WOW! Now that I am at the 15-16 hour mark, I think I have a pretty good handle on how the midrange is coming along. I have now thrown 6-7 reference disc at these speakers to really put them through their paces. There is one recording that really stood out. I recently had a friend that sent me Tommy Emmanuel - Only. For those who are not familiar with this recording, it's many wonderful tracks of the best recorded acoustic guitar I have ever come across. Listening to this recording makes you feel like he is in the room with you (I know, everyone says that). With the OB-7's open baffle midrange, there were no speakers in the room. I won't tell you that there was music coming from every direction because that's not what a acoustic guitar does. In this case, it sounded just like what you would expect from one man sitting on a stool right in front of you playing the guitar. The sense of realism was uncanny. You could here Tommy take a breath and I think I even heard his pants ruffle when he shifted his body. Obviously a close miked recording. I have heard a lot of speakers in my days and in this regard, the OB-7 can easily compete with the very best.
Conclusion:
Overall, I found the OB-7 to perform far beyond what one would expect from such an inexpensive speaker (as compared to the alternatives). You do not hear the transitions at the crossover points which is a honorable task for a 3-way design. The upper end presence, air and extension is breathtaking without any fatigue. The lower registers are clean and fast just the way I like it and the midrange is open, spacious and holographic. There is no particular frequency range that stands out or is overwhelming except for the bass which is controlled by the BMS. The complete presentation is clean and smooth without being overly warm.
Both male and female vocals come across with a great sense of realism. Seperation of instruments is on par with some of the best speakers i've heard and the spaciousness created by the open baffle midrange can easily throw a soundstage wide and deep.
They will play plenty loud without loosing their soul as well as retaining phenomenal resolution at even the lowest listening levels. And to think, all this with less than 20 hours on the speakers and the standard crossovers with no Teflon bypasses. I think we are in for a big treat in the near future as things will continue to get even better.
Set-up
Speakers are 9.5 ft. apart --- listening position is 13 ft back
4 feet from side walls and 4.5' into the room from the wall behind them -- toed in slightly
Listening area: 17' W x 30' D x 10.5' H into an L shape
Overall room: 1300 sq. ft.
Temporary evaluation system
Bella EXtreme 3205 MK II Reference amplifier (Big Blue)
Audio Note Custom L3 deluxe preamp
Audio Note Custom DAC 2.1 Deluce
Jolida Custom Level 2 modified CD player (used only as a transport)
Proototype Silver/Gold interconnect cables
Prototype Silver/Gold foil speaker cables
VH Audio AIRSINE and Flavor 4 power cords.
References
Joss Stone - Soul Sessions
Tommy Emmanuel - Only
Jacek Kochan - Another Blowfish
A twist of Jobim
Craig Chaquico - Panorama
Michael Bolton - Greatest Hits 1985-1995
Jimmy Rogers - Bluebird
Rick James - Ultimate Collection
BB King - Ultimate Collection
Norah Johns - Feels Like Home
Metallica - Justice for all
Devo - Greatest Hits
