[Bill Baker]

I figured I would start a new thread and consolidate the talk about our custom outboard crossovers as well as finished speaker offerings into a single thread.

 These speakers were built in house based on Denny's flat pack cabinet kits so we could get a pair running to start on the outboard crossover tweaks. Our finished speakers will have cabinets custom built by Denny as can be seen on our website as well as throughout various discussions here on AC.

 I now have the speakers up and running and will continue to put some hours on them over the next several days before critically evaluating their performance. At this time, I have decided to leave out all the Platinum Teflon bypass capacitors and the tweeter level control until I get a handle on where I am with them. They are running with the BMS active. I found that in my 1300 sq. ft. room, I still needed to tone the bass output down a bit but more on that later.

 Well, I don't want to waste any more of your time with type (I can do that later ) so here are some pictures.

Let's start by giving credit where credit is due.



Showing the Speak-On connectors that connect the outboard crossover to the speaker cabinet. There are two different types of connectors used here as well as the umbilical cords being labeled so there is no chance of hooking things up wrong.


Prototype crossover box that was thrown together quickly and design to give me easy access to the crossover for tweaking the BMS and TLC.


Up and running in a system making Musica Bella (beautiful music)


A close up shot.

[Bill Baker]

Just as a quick teaser.....for those of you who have ordered these speakers or building your own, you are in for a treat. Mine have been running for about 8 hours now. I was planning on leaving at 6PM this evening...it's now 10PM and I'm still here. I can't pull myself away. That's all for now.

[lonewolfny42]

Nice work Bill....

Happy listening......

[pbrstreetgang]

Ah good to hear, I was a little concerned when you didnt mention anything on the sound at first.

[Bill Baker]

Ah good to hear, I was a little concerned when you didnt mention anything on the sound at first.

 

Have no worries. I am taking notes and will do a write up soon enough. I promise you will not be disappointed with these speakers. If I remember correctly, you are also running the upgraded M130X woofers as well?

[pbrstreetgang]

Yea I got the 130Xs too so Im interested on hearing

[Bill Baker]

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

[Bill Baker]

A few have asked me why I don't have the Bella 100 amplifiers shown in the pictures driving these speakers. Okay, give me a few days and I will hook them up to the OB-7s

[saisunil]

Nice Review! Sounds like my kind of a speaker

[arthurs]

Rick James AND Devo?  You never cease to surprise me Bill!

[pbrstreetgang]

Devo kicks arse- well synthesizer anyway. Not that there is anything wrong with that.

[ecramer]

Sounds like a road trip may be in order in a couple of weeks I want to hear these speakers 

[Bill Baker]

Rick James AND Devo?  You never cease to surprise me Bill!

You may be shocked at some of the stuff I listen to.  aa Sugar Hill Gang was cranking last night. The original extended version of Rappers Delight.

Devo kicks arse- well synthesizer anyway. Not that there is anything wrong with that.

First concert I attended. I was 12 years old sitting in the balcony at the Platium (spelling?) in NYC. Came home with a buzz from all the 'smoke' rising. Even met the band back stage afterwards.

Sounds like a road trip may be in order in a couple of weeks I want to hear these speakers

Any time....you are welcome. By then, there will be a few more goodies to hear as well.

Nice Review! Sounds like my kind of a speaker

Thank you saisunil. I will post a bit more once they are fully broken in.

[Bill Baker]

Greetings everyone,
 After spending another 8 hours listening to the OB-7 deluxes today, I have come to the conclusion that a tweeter level control is not needed. Danny did such a fine job with the crossover design that a level control would only degrade the perfect integration between the mid woofers and planar tweeter.

 For those who would still like to have a bit of attenuation up top, I am still experimenting with incorperating a slight amount. Maybe some will have a 'hot' room?

 However, the bass management system is somethng I believe most users will want and need. My room is very large and I still had to utilize the BMS as not to have the bass output (60Hz - 80Hz region) overwhelm the room.

 For those who have inquired about purchasing out outboard crossovers or finished speakers, please let me know the size of your room at time of ordering. I will tweak the BMS to best suit your room yet still be very versatile. Basically, I only need to know if it is a small to average size room or a very large room. Smaller room may need more adjustment than others.

 Keep in mind that this only applies to the OB-7 speakers with the upgraded M130X woofer option.

[Bill Baker]

 I will be at the shop both Saturday and Sunday this weekend and will be hooking up the Bella 100 amplifiers and doing a bit more tweaking on the BMS after taking some in-room measurements.

 The main system will contain the following:
* Bella EXtreme Custom Mundorf 100 amplifiers
* Audio Note Custom L3 Deluxe preamp (transformer coupled output) running balance to the amps.
* Jolida JD100 Level 2 modified player
* Prototype SG Series 1 Silver/Gold interconnects
* Prototype SG17 Silver/Gold foil speaker cable

 I may have some people in on Sunday picking up some amplifiers and maybe I can get them to post some thoughts on the OB-7's. (one of them is an AC member)

[bpape]

I really like the way you finished those Bill.  Love the light wood on the baffles with the black back box. 

Bryan

[Bill Baker]

I really like the way you finished those Bill.  Love the light wood on the baffles with the black back box. 

Bryan

 Thank you Bryan. The baffle is finished in Cherry with only an oil finish applied. The reason for going with this is do to the how nicely Cherry darkens with age. I still have the first pair of speakers I built in 1995 that were finished in Cherry. When I first applied the veneer, it was very light, almost yellowish, it now has a deep tone to it.

  Now I just have to finish the base. I will be doing this in a black textured finish for a nice contrast.

[bsuhy]

I love acoustic guitar music and just ordered the Tommy Emmanuel CD from Amazon after listening to a few clips, thanks for sharing. I dont want to divert the thread, but do you have any other recommendations for solo acoustic guitar? It seems to be really hit or miss.. I have all of Michael Hedges CD's, his music and technique are simply amazing, especially Aerial Boundaries, and I like the rest of the usual suspects (Paco, Kottke, Legg, Dykes, etc)...
Oh, the speakers look fabulous, I wish I had the skill to build them...

[Bill Baker]

Hello bsuhy, I think you will really enjoy the Tommy Emmanuel recording. Do let us know what you think and don't worry about posting it here on this thread.

If you don't already have it in your arsenal, the Craig Chaquico - Panorama recording is another must have in my opinion. This has been a long time reference for me.

 I will have to check out a few of the recordings you mentioned as half of my music has come from customer referrals over the years. I have yet to be disappointed. Now I just have to come across some really good brass recordings. I am also a big fan of a good sax or trumpet. I would have to say the sax is my favorite and oddly enough, the harmonica comes in right after that.

 Thanks for the comments on the speakers. I only wish I had more time to do a more elaborate finish. I had to get these done quickly so I could finalize the tweaking on the crossover for those here at AC that expressed interest in our finished product and/or custom outboard crossovers.

 I will be building a pair of the OB-5's soon and maybe I will take my time and apply the Japanese Tamo or Olive Burl I have been wanting for so long.

[Bill Baker]

Oh, the speakers look fabulous, I wish I had the skill to build them...

 Hey bsuhy, no need to be intimidated about building these speakers. With Denny's flat pack, anyone who can put together a puzzle can assemble them. All the hard work is already done.....the cutting. Hell, I had my pair up and running within 12 hours from the time my flat pack arrived at my door.

There are also a few threads here on AC with step by step picture instructions and pictures to guide you through it.

Here is one of my build
http://www.audiocircle.com/index.php?topic=49491.20

And one of another AC member's build
http://www.audiocircle.com/index.php?topic=50784.0

 If the crossovers scare you, we can assemble these for you even. If interested in the outboard crossovers, Denny and I have already worked out the details so your back panel comes with a plate ready for the speak-on connectors. Just plug them in and start listening