Mostly JBL Pro DIY 3-Way

[NWCgrad]

Based on what I have learned from this forum (and others) I built a rather large, JBLish 3-way speaker. Design goal was to have horn loading from 200 Hz up. The midhorn is the one designed by Wayne Parham (Pi Speakers). Thanks to Speakerdave I will shortly have a pair of JBL2012H's for the midhorn (currently using 20123H's which are not optimal for this application).

Computer Drawing of the speaker concept:


Enclosure Design:


The numbers to the left of the concept speaker are the center-to-center distances and the height from the floor to the midpoint between the MF and HF drivers.

Temporary XO/DSP is provided by a Peavey VSX26 unit. I added a protective capacitor (39 uF, ~510 Hz 1st order) and L-pad attenuation circuit (-6 dB) to the HF driver. The Peavey VSX26 is known to add hiss if used to attenuate the signal, thus I provided most of the required attenuation passively (remainder is added at the amp).

I will be working on the XO/DSP settings, which is likely to be continual learning process. Goal of the design is for my ability - somewhat limited as I am electronically challenged - to dial in the speakers to be the weak link.

Thanks for looking.

[NWCgrad]

A few construction photo's:










I pilfered the 22242 drivers from the 4645B cabinets shown in the picture above. I shot for a net cabinet size of 8 cu ft for the build so I could match the tune of the 4645B cabinet which are fantastic in my view (especially for music). I am not chasing single digit bass, I am happy for solid performance to 20 Hz when coupled with a pair of DIY subs feature Eminence Lab12 drivers.

[NWCgrad]

Close-up of the midhorn (with a JBL 2123H driver):


Initial position in the room, will play with toe-in as I optimize:


I went with a blue color (Behr marquis "Real Navy") as a spur of the moment decision in Home Depot. I was tired of standard black speakers. The Real Navy color seemed appropriate as the speakers are my gift to myself for making 06 in the navy.

[NWCgrad]

A few more construction photo's to cap off the build portion, Baltic birch was used exclusively (except for a couple of 2x4 braces).





Note: The ports are not blocked by the material used to secure the insulation. I used small pieces of hardboard and a nail gun to secure the fabric to the braces to ensure they do not sag over time and block the ports.

[srm51555]

Nice build, thanks for sharing.

[NWCgrad]

Nice build, thanks for sharing.

Thanks...my wife was getting tired of the stacked speakers dominating the front of the home theater/family room. These speakers, while rather large, take up much less visual space than the stack they replace.

[JeffW]

Heck of a concept, I bet those really get up and boogie!

[NWCgrad]

Heck of a concept, I bet those really get up and boogie!

They surely do! Listening to Bela Fleck and the Flecktones "Flight of the Cosmic Hippo" is really something!

Here is adown and dirty measurement from the listening position (13.5') of the speakers with two subwoofers (20 hz tuning, Lab-12 drivers):

It needs a LOT of work. Didn't have time to properly integrate the subs and it is clearly super hot down low, not really ready for prime time. I toned down the bass based on listening sessions but have not yet had time to break our REW and measure. Will be swapping out mid drivers soon, will then really start to dial in the system.

[daveschott]

They surely do! Listening to Bela Fleck and the Flecktones "Flight of the Cosmic Hippo" is really something!

Be careful when playing that tune, those may damage your houses's foundation!

[1audiohack]

Looks like my kind of loud speaker! Nicely done.

Barry.

[NWCgrad]

So far I have found them to be very enjoyable.

I hope they sound even better soon. The 2012H drivers arrived yesterday from speakerdave. They were packaged to survive the rigors of shipping and arrived in perfect condition. I cannot wait to get one installed so I can measure how it performs compared to the 2123H.

[1audiohack]

I have a pretty good idea of how this will turn out.

I like 2123's quite a bit but a 2020 on a horn is a marvelous thing!

Barry.

[NWCgrad]

I installed one of the 2012's yesterday and made a lot of measurements with REW at a microphone distance of 33.5" (this distance was based on a 36" aluminum bar pushed up against the front of the speaker and my microphone stand placed at the end of the bar, this allowed me to move from speaker to speaker and have repeatable measurements). I was surprised to find that neither driver really performed better than the other, and using 4 DSP equalization points was able to get both +/- 1 dB across the required frequency range.

Things that make you hmmmmm and what the heck!

[grumpy]

I would call this a good result, as FR is only one of many measurements...
Then there is the listening

[NWCgrad]

Listening is always the final word!

I need to change the thread title, just ordered a pair of the STX/VTX 90x40 waveguides and JBL 2453H-SL drivers. The Speaker Exchange has a ridiculous prive on the 2453H-SL drivers, at less than $280 ea brand new I couldn't justify going with one of the older (yet higher quality) drivers.The aquaplas coating is critical for home usage in my view, raw titanium is to much for up close listening (13 ft distance from speaker to the primary listening position).

Will require lots more measurements and tweaking. Now i will be able to crossover to the midhorn around 1 kHz. Hard to do that with the B&C DE250.