DIY Hybrid OB Bookshelf - Update

For those who don't know about the build, this is the original thread.

It has been a some time now, and all I can say is WOW!!! To me these speakers sound amazingly good for what they are. So clear, decent bass, nice looking, mids to die for, and airy highs. No, they are not perfect, no speaker is, are they good, don't tell Paul Barton, but better sounding that my beloved PSB B15's, much better than my B25's (B25 can go lower). I have said over and over again that as of today my preferred speaker is Revel's M105/106. This is not a Revel M105, but is darn close to its sound; quite a statement, but that's what I feel. I'm sure the enclosure design can be improved (for example, round off the baffle edges), and other things can be improved as to get more bass. I hooked my old Audio Source SA-50 8" sub (very first sub owned) to the system, and the sound got even better. Extremely happy with the results, though I'm still playing with active crossover settings, it seems that the best results are obtained at 700-800Hz, still debating. When I build a passive will most probably go with a 2nd Order LR, though a simple 1st Order Butterworth might work well in this speaker design. Not a crossover guru, so if someone wants to chime in with a suggestion for passive design, it will be appreciated. Also, an L-Pad with -4dB is a good idea, as though both drivers have basically the same sensitivity, the MarkAudio in its OB configuration seems to overpower the vented (1" Dia x 2" L) enclosure HiVi, in the active crossover I have to lower the gain of the MarkAudio by -4dB. But at the same time, it is not "un peo que rompa calzoncillos" (translate from Spanish to English or whatever your language is).

As for the drivers, I expected the MarkAudio CHR-70A.3to be a good full range driver, and used for mids and up, they are extremely good, especially in the high range, didn't expect it to be so good in the high range, they don't disappoint. Though in a single driver design I don't see the MarkAudio to give much bass extension. But, even more impressed with the HiVi M5N, I consider it an overachiever, its sound is extremely good, no wonder the 4" version is highly praised used in PE's Overnight Sensation speaker.

In my case, I didn't design the speaker as to use any drivers. My goal had to do a lot with aesthetics (WAF), so the dims of the enclosure is based on the correct volume for the HiVi M5N, but with width, length and depth had to look right, and the front baffle needed the right height based on my stands, so 16" total height for the baffle seemed correct as to have a proportionally pleasing bookshelf speaker. The drivers were selected based on the combination of performance and looks. The gold-champagne color of the drivers are almost identical. To me a black driver with a driver of another color simply didn't look aesthetically pleasing. Anyways, if you want to do an equal or similar speaker use the driver you think works best and design around them. Personally, I designed the enclosure I wanted, and selected the drivers based on the enclosure. Ak'er Donkey Karma ordered the same drivers as to build the same, he already advised he will round the baffle edges, he will go with a 1st Order passive crossover, and he will experiment with different weights of poly-fill (I will do the same on my end).

I guess that once everything is dialed in and passive crossovers have been installed, in lieu of the active crossover being used, I will try my best to do a proper "review" post.

Something lost in translation?

"a peo that breaks his underwear"???????
Sorry, I think BING has been smoking a little too much, tonight!!!
BTW: Great speaker build!!
Ammon

jammon said:

"a peo that breaks his underwear"???????
Sorry, I think BING has been smoking a little too much, tonight!!!
BTW: Great speaker build!!
Ammon

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I prefer Google Translator, but BING is sort of close, actually "a fart that doesn't break your briefs (underwear)", or better said "it is not a fart that will break your briefs" (basically not of importance).

Thanks!

BTW, total cost of this project is approx. $200.00 to $250.00 for the pair, including wood, drivers, hardware, crossover, and veneer.

As you no doubt have learned from these really nice OB's DIY is highly addictive. The self satisfaction from a job well done yearns for more.

So what are you planning to do for an encore? :thmbsp:

Poultrygeist said:

As you no doubt have learned from these really nice OB's DIY is highly addictive. The self satisfaction from a job well done yearns for more.

So what are you planning to do for an encore? :thmbsp:

Click to expand...

Because of the size of the rooms where I have my audio equipment, one is a dedicated multimedia/listening room, which I don't use much due to high demand for the room, the other being a secondary living room which is long, but not that deep (13') and full of furniture that gets on the way, I cannot go with larger OB's, so the Hybrid concept works well in my room. I'm thinking of putting up for sale my PSB Image 5.0 system (will keep the HSU sub), and build a pair of Hybrid OB Towers in a 3 Way configuration by using a pair of 6-1/2" woofers, a 4" midrange (I really like the HiVi M4N) and a tweeter to be decided, but leaning towards an AMT or Ribbon, just because I have never used one. Even thought of integrating side firing sub in the enclosure, in which case I will probably forego the dual 6-1/2" woofers and use a capable 6-1/2" full range driver plus the tweeter, giving it more thought. I would also build a center channel to match, but obviously not OB, just an enclosed design. As always beauty has to match sound, so the enclosures will most probably be unique; in the sailboat I race there are two (2) new crewmen, one is a very well known and highly capable industrial designer (though he has designed and fabricated unbelievable stuff, his most simple design is the most famous; the PVC Domino Table), the other crew is an architect that owns one of the best woodwork shops in the island: He has CNC and all those high end tools that make perfect and difficult shapes, cuts, designs, etc. And he has placed them at my disposal!!! So, the future of my DIY projects looks good. :thmbsp:

One thing about the Hybrid DIY OB Bookshelf, it excels at classical, jazz, salsa, ska, reggae, and music that is heavy on the brass, piano, and strings; sounding very life like and engulfing you in the experience.

Yes I am completely coat tailing this build.

MarkAudio (gen 3) is on back order. Actually exchanged emails with Mark and my pair should be arriving by the end the Month. Discussed 1st order crossover components with PRA last night. Parts en route. Begin work on the cabs this weekend. First DIY from the ground up. PR did his homework here, expecting excellent results.

Donkey Karma said:

Yes I am completely coat tailing this build.

MarkAudio (gen 3) is on back order. Actually exchanged emails with Mark and my pair should be arriving by the end the Month. Discussed 1st order crossover components with PRA last night. Parts en route. Begin work on the cabs this weekend. Front DIY from the ground up. PR did his homework here, expecting excellent results.

Click to expand...

Look forward to hearing your impressions!

Yes, hopfully it's SOON:thmbsp:

It has been awhile!!! Equipment problems didn't allow me to fine tune the speakers using the active crossover. Though equipment issues not totally resolved, I am upgrading my family room HT/Music system, which allowed me to take my Marantz SR-5001 off HT duty, and use it as an extra "amp" in my main music system. From the active crossover I run the lows interconnects to my DIY Class D Amp, and the highs interconnects to the front panel Aux 1 RCA inputs of my SR-5001, and control both with my McIntosh MX-113 Pre-Amp. The fact that I can run the Marantz in PURE DIRECT Mode is a big plus, as basically the pure signal from the MX-113 goes to the amplification section of the Marantz receiver. I did this today. The DIY Amp as well as the receiver have a max. output rating of 80 WPC @ 8 Ohms...

I have not taken measurements with a mic (Dayton IMM-6) and IPhone App Audio Tools by Andrew Smith/Studio Six Digital, which I will use tomorrow for the first time. So, at this time I'm going by ear using music, not a pink noise signal...

I have mentioned in the past that I was running this speakers without crossover, just letting both drivers run at full range. The sound was very good, but there were some issues, like too bright for my taste and there was certainly a bump in the mid range, which made voices extremely clear but not balanced with the rest of the music; voices and mid-range frequencies were louder...

My initial simulations determined that the best x-over point would be around 650 Hz, and to my ear it was almost dead on. But, there was something missing, airiness and sizzle of the highs was missing, plus the speaker was not as warm sounding, as I like them. It was on the neutral side. The dynamics were there, the detail was there, but mids were sort of forward, and highs were somewhat muffled. So, played with the active x-over to see where will my ears feel satisfied with the sound coming from the speakers. After hearing the same music over and over I noticed that Etta, Diana Krall, female jazz singers in general, jazz, Tracy Chapman, reggae, Frank Sinatra, classical, drum and bass, and the likes sounded best at 1,500 Hz. But, classic rock, Stevie Nicks, pop, electronic, salsa, and brass instruments sounded best crossed at 850 Hz. So, had to look at a mid point, where all the music I play sounds good; knowing that might loose some of the specific SQ of each genre. Finally, I settled with a x-over point of 1,200 Hz with a -4 dB gain and inverted phase for the highs...

The result is an excellent sounding speaker, that is very clear, warm, detailed, and has those NOT annoying airy and sizzling highs that, IMO, everyone likes. Bass extension is darn good for a 5" mid-woofer, no distortion, very clear, not muddy; need to take measurements, but IMHO bass is down to the mid to low 50's Hz. Mids is where this speaker shines, voices and instruments in this range so clear, detailed without being annoying, excellent transitions, you can clearly discern voices, instruments, and other details that sometime we miss. As for highs, the Mark Audio CHR-70A.3 really shines in that department, very airy, top hats/cymbals sizzle, not harsh at all, so far I have not heard such nice highs in any speaker I have owned (mostly PSB). What really surprised me was soundstage and headroom. Soundstage is wide, well beyond the outer edge of the speakers, deep and quiet; you can easily tell where the instrument, chorus, and/or singer is placed in that soundstage. Live recordings sound like if you are in the middle of the crowd. When it comes to headroom, it was a new experience to me (speakers are 16" high mounted on 29" tall Lovan bookshelf stands filled with sand and leadshots), while sitting on the floor between the speakers, close to them, and "playing" with the active x-over, I realized that the music sounded like if I was sitting on the floor in front of a stage, and the stage was about 36" high, like the stage of a pub or club. Then, when sitting with my ears slightly below the full range drivers, it felt like if I was standing in front of that stage, and in order to feel like the music coming almost straight on I had to raise my ears about 12" over the speakers. As for imaging, being a hybrid design with a driver in OB configuration, the speakers simply disappear, leaving the soundstage open. When one does an analysis like this one, you understand what the pro reviewers mean with their fancy adjectives and analogies; though sometimes overdone. Is this a perfect speaker, not at all!!! Nor, I pretend for you guys to believe they are; after all a compromise had to be reached in order to make them sound their best with all kind of music genres. But, at a total cost of $225.00, including drivers, 1/2" MDF, veneer, 3/8" wool liner, bi-amp banana connectors, XLR to RCA adapters, and Behringer CX active crossover, these are a bargain. Take the active crossover and adapters off the equation, and build your own 2-Way/Second Order/1,200 Hz/-3.5 dB L-pad x-over and you have an excellent pair of bookshelf speakers for approx. $170.00...

I wonder how will they sound in an HT setting, with a center channel using two M5N woofers with a CHR-70A.3 driver in the middle, or simply three CHR-70A.3 drivers...

As soon as I take measurements I will post results.