JBL V2600 new DIY

[vernb]

So I sold my JBL 1400PRO basses. They had the best midrange for 2-way speakers I ever heard, but no deep bass response worth speaking of. I was warned by good members of this forum though, but had to try.

Now I pulled the front of the cabinets out to make a new one, still for the H2600 horns and 276ND drivers, but this time with a nice old set of 123a-1 bass drivers.

Troels Graversen wrote a long time ago on his website, that these drivers were excellent for LF in big closed cabinets ( I have around 100 litres) and also excellent for playing all the way up to 750hz as I do here using the basics from the JBL S2600/S3100 crossover.

[vernb]

I use Audio Research LS-3B as preamp and Marantz Esotec MA-5 mono poweramps for the LF, and Proceed AMP2 for HF.

Sound is better than I expected, and I am very pleased with the very low LF that the 123a-1 drivers give me.

I want to try out my Luxman MQ36 OTL tube poweramp for the HF, but haven't had time yet. Perhaps next week.

[JoMoCo]

:beach:After you spent some time with them, please post your listening impressions / comparison...:hmm:

I have also heard they work in smaller sealed cabs down to 1.85 cf or so...:dancin::banana::dancin:

I would be interested in your application...100 liters are approx = 3.53 cubic feet...:rockon1:

[demon]

the new speakers look nice, somehow relaxed and friendly to me. i dont know about what the horn needs, but do you think about getting a compressiondriver from the same era as the woofer?
(i find that most cone drivers have a very pronounced character, compromised of size and curvature, color and surface. the 12inch white cones always stood out, and where among the first things catching my attention to jbl. industrialdesigners deliberatly use these different characteristics to catch attentions...:o:)

id like to read impressions too, thanks!

cheers,
mikey

[clmrt]

I went the opposite direction - From 123A-1 in 3.3 cubic feet sealed to E145-8 in 4.5 ft, vented @ 43.

I do miss the kick drums and lower tones as rendered by the 123, but the 145 is capable if prodded by a bit of EQ.

I find myself dreaming of the 123 again. Perhaps the Peerless 830669, the curves are almost identical in WinISD.

[vernb]

as you can see, here is the crossover I am using, but I have removed the two 82ohm resistors, due to the lower sensitivity of the 123a-1 basses.

[vernb]

The sound is really good, and I haven't even considered changing the 276ND to older drivers.
The 123a-1 do a really good job in the big sealed cabinets. They measure 40x60x70cm externally. They are very thick cabinets and have a lot of internal damping material on all sides except the fronts, giving around 120litres of internal volume.
Bas response is like the best JBL speakers I have heard regarding very LF, but of course they don't have quite the dynamics of bigger high sensitivity 15" drivers in reflex cabinets, or my 1400PRO drivers, but it's good sound, real good sound.

I never really thought that the older drivers were always better than the newer ones. Some of the old bass drivers are really good, but a lot of the new drivers are really good too. 2450, 276ND and 2226 are good examples of new drivers that are extremely good in my opinion. I think that all new compression drivers do a lot of a better job from 12kHz and up than the older ones, and I am very happy with my 276ND drivers.

123a-1 is a good match and they are definately staying.

[Fangio]

Thanks for the inspiration. I have a pair 879A cabinets with removable baffles (so everything is reversible), and a pair 123A-1's too.

Cab volume is about 100 liters also – bigger than Jubals, smaller than 4320/4333 somewhere in the middle. I really really like what a pair of those lightweight cone JBL 15's currently does in there... fits right in even with the original t-nuts in place. However when I get around to make some new baffles I might as well have another 12" version cut to give it a whirl, and see what they are capable of.

[vernb]

Well I changed my system a bit. Now using Luxman C-05 preamplifier and the Proceed AMP2 just for driving the 123a-1 woofers. For the horns I have put on my Luxman MQ-36 OTL tube poweramp (from 1963). Honey for the ears. This is a fantastic combination.
The MQ-36 only have 16ohm and 32ohm tabs, but seems to work just fine with the 276ND drivers on the H-2600 horns.

It is a very big heavy thing that I bought from a dear friend last year.

[JoMoCo]

:dancin:

[clmrt]

Still in love?