2245 active 3 way

[Dan]

I purchased 2 JBL 2245 on ebay for $219 each and asked the seller to ship it to Orange County Speakers to have it reconed with the original recone kit.

[Dan]

CNC cut parts


internal bracing


First box almost done


insulation from recycled jeans from Lowes


Cutting the vents from a 4" pvc pipe

[Dan]

JBL 2245 (95db) + Beyma 8" mid 8m70V2 (95db), Beyma TPL-150 with custom waveguide (100db)


Crown K1 driving the 2245 + Behringer DCX 2496


View of my listening room/ hometheater


(3) 41hz Amp 6 on battery power driving the TPL-150, each amp in parallel mono at 12 watts each. Not seen in the pic are (2) 41hz Amp 4 (25watts) driving the Beyma 8" mid. Mini DSP is used for the mid/ tweeter with a tweeter delay of .06ms.

Cross over points LR-24 300hz, 1.2k

[just4kinks]

Cool. I like how you did the bracing, do you have one of those CNC router machines?

And the most important question: how does it sound?

[martin_wu99]

So cool,congrats

[pos]

Very nice setup Dan! I which I had your woodworking skills!

Did you measure your setup to establish the filter/eq topology?
How did you handle the baffle step of the midbox?
Given the width of that box, it probably makes the 300Hz crossover quite difficult to operate.

[Lee in Montreal]

Very nice work. I love CNC wood cutting.

BTW Are you sure that Orange County installed original JBL recones? The size of the dome, as well as the two "traces" look quite different from mine. Or perhaps they are the new "Hecho in Mexico" JBL cone kits.

Great stuffing too. What is the source for those?

[Dan]

Cool. I like how you did the bracing, do you have one of those CNC router machines?

And the most important question: how does it sound?

The box is very solid considering its cut from 3/4" MDF. It is also very heavy.

I don't own the CNC. At one point I was considering on getting one. A local shop with a CNC cuts the parts for me. These are just test boxes. The fit is not so good. I had to make a lot of adjustments manually. I will modify the parts in the computer before CNC cutting the final boxes. I will make a new set to be veneered with walnut. The waveguide will be milled in solid walnut.

I'm very happy with the sound. The bass/ lower mid bass from the 2245 is so clear, tight and dynamic. Its one of the best I have heard or felt. The entire system images very well. The speakers disappear in front of you. All you hear is the music. No listening fatigue.

I started this project more than 3 years ago. I have tried a lot of things and drivers, including a JBL 2123 for the mid. So far this version works really well.

You can come over and listen to them if you like.

Dan

[Dan]

Very nice work. I love CNC wood cutting.

BTW Are you sure that Orange County installed original JBL recones? The size of the dome, as well as the two "traces" look quite different from mine. Or perhaps they are the new "Hecho in Mexico" JBL cone kits.

Great stuffing too. What is the source for those?

I made sure that Orange County installed the original recone kit. I hope they did. You can see the price on the receipt. The back of the cone is coated (aquaplas).

I bought the stuffing from Lowes home improvement store. They are like Home Depot.

Dan

[Dan]

Very nice setup Dan! I which I had your woodworking skills!

Did you measure your setup to establish the filter/eq topology?
How did you handle the baffle step of the midbox?
Given the width of that box, it probably makes the 300Hz crossover quite difficult to operate.

Thank you for the compliment. My wood working skills are about average. Its the CNC machine that did the cutting

I have not made any compensation for the baffle step yet. So far it sounds good already. It is a big improvement from the previous version using a 15" SB Acoustics woofer in a sealed box.

I use True RTA software to make the measurements for the corssover points. I'll try to post a screen shot of the response. I just finished the boxes a few days ago so I haven't measured them yet.

I used Bass Box Pro to design the box. I made simulations for 7.5(suggested by software), 8, 9, 10 cuft. I chose the 8 cuft because it seems to best fullfil my requirements on size and performance. Fb of 26hz was also suggested by the software. I'm still playing around with the boost settings. Right now it is at 26hz +6 db, Q=2

Dan

[Chas]

The stuffing used looks to me like the sort of insulation used for acoustic insulation for inside home between room walls. I would guess that it would react differently compared to fibreglas as it is usually much more dense. But, if you achieve your desired Fb, then it's all good.

[Lee in Montreal]

I thnk I saw that type of acoustic stuffing at Home Depot last week. i'd prefer that to fiberglass, which is obviously not as bad as asbestos, but not something you want in your lungs and eyes...

Lee

[dr_gallup]

Very cool. Love to see the final veneered boxes. I like that insulation but I suspect it will react differently than fiberglass. Will be interested in seeing some response curves. I'm a big 2245 fan too but I just have one in a sub.

[Dan]

The stuffing used looks to me like the sort of insulation used for acoustic insulation for inside home between room walls. I would guess that it would react differently compared to fibreglas as it is usually much more dense. But, if you achieve your desired Fb, then it's all good.

[Dan]

Here is the frequency response from my listening position. I couldn't do a screen shot so I just took a pic of the screen.