AHall

I really have no desire to mess with Roy’s handy work. Especially since the 1802 has been designed and tested with dual sealed, single driver with vent, and passive radiators. The current vented design is the one that tested best and made it into production. The exception to this in my mind is the original purpose was to dig low with extreme output for huge rooms or open space, cinema and concert. It wasn’t designed to dig ultra low for a home theater. So I don’t mind “optimizing” it to be more ideal in the situation I’m using it for. If dual sealed will go lower and still have awesome output while maintaining full critical listening fidelity I’d be even more happy. I fear I could introduce unwanted distortion to the system by using different drivers or changing things too much.

There has been talk of adding a second driver. Could be worth a shot and fun to experiment with. Going from a ported to sealed cabinet might present an issue if the factory driver is ideal to be used in a sealed application with the size of box. I don’t know enough about the matter. Maybe a sub driver guru could chime in. For example with the cab size I wonder if a couple ultimax 18’s would be more ideal in the sealed unit than buying a second k-473. Which appears to be an eminence driver.

I think I have determined that the 1802 has the capability to go nice and low with dsp. I also think that by boosting the bottom some to gain that flat response and low extension you are limiting the overall output of the sub. Information under 20hz gets sent to the subwoofer and can cause it to bottom out at moderate listening levels. Levels where the 1802 is barely warming up at say 25hz. Even though the graph looks good on paper I think not using the suggested high pass filter will limit the total spl greatly. Currently I am enjoying the extra low end extension and it will go far above reference levels, but if you want the total advertised spl I think it is best to have it roll off. My plan is to use only the 1802 for music purposes and build several large displacement 18s or a couple 24s at the back of the room to assist in ultra low LFE for movies. I think large sealed subs would be better for this duty than asking the 1802 to do something it wasn’t designed for. Anyone care to add some input on this or correct my thinking?

Current update. Redid some eq. This is the current response at the listening position. Added a bit of a house curve into the peq. Still using 2 ports closed. I haven’t noticed any negative results as of yet.

I like the ct120s in my khorns better than the ct125 I have in my cornwalls. The a55g was a nice improvement as well.

The only thing I can report on this is I prefer the performance of the jubilee to my friend’s dunlavy sc-IV and sound labs. Much prefer them over my khorns. My uncle has Martin Logan CLX Art and is a huge electrostat guy. He came over to demo my jubes and we spent a whole evening. He said he actually preferred my setup over his. This might be because he is more of an old school rocker and the jubes and large horn loaded sub present so much energy and impact without effort. I haven’t had a chance to listen to his setup so I really can’t claim this demo as first hand info.

It was more of a curiousity than anything for our experienced listeners. I’ve never seen much chatter about it. For the most part you seem to have the people that have jube experience that haven’t had a chance to compare them to other highly regarded speakers. Then you have the people that haven’t heard jubes that assume they sound like big PA speakers. Just an observation.

2way Jubilees are about $6500-8000 depending on the crossover and veneer option.

Its just for fun. I’ll never be able to afford or justify $100k speakers anyway so it won’t hurt my feelings.

Question for the people that own or have experienced Jubilees with premium gear and drivers. Has anyone also listened to the very expensive premium speakers like Wilson, Magico, Focal, Martin Logan, Avantgarde, etc? I haven’t had the pleasure to do so yet, but hope to this year at RMAF. I was curious of your specific and overall thoughts on the matter. I know the this vs that is fairly pointless, but what the hay.

I told my wife I was gonna sell the jubes and 1802 to buy some smaller prettier speakers and she said not to because she really liked em. I’ll take that as a win. Ive seen quite a bit more chatter on the 402 and 510 on some other forums as well. Although it doesn’t do me much good in finding some used 510s.

Im sure it’ll be a nice improvement for voices, but I won’t be satisfied til I build an adequate bass bin.

I found a nice used radian 950pb-16 on eBay to try in a k510 for my center channel. Should be a fun experiment using my heresy for the LF cab. I tried it once with the included k69 but I think that driver diaphragm might have been messed up because it sounded very odd.

Yes lead is much lighter and stiffer than beryllium.

The factory k691’s did sound very good. I am happier with the new Radian 950pb drivers I replaced them with. I think they were a good bang for buck upgrade.

How do you like the SIT amp. I think I’m going to try to build one when Nelson Pass finishes the new batch of sit transistors soon. The reviews say they have a triode tubey sound to them without all the tube headache. I think this would be ideal for 402s

I think you’d lose a lot of your spl going from horn loaded ported to hornloaded sealed in a big box. The response is already pretty flat and would be borderline inaudible. Most graphs are in a 5-10db scale usually. I like everyone to see what’s going on better. I have the xilica dsp controlling this as well.

He mentioned he went with the 7 port design due to high spl levels for cinema use. I should be good with the current 5 port configuration and have enough spl to go deaf. Closing another port will get me lower but might be approaching the limit of the amount of spl the 4 ports will generate and create chuffing. I will need to play content to see if I run into this issue. So my plan is to leave it how it is with 2 ports closed. I’ll play some music and movies at high spl to see if I get any negative results. Then I’ll repeat with the third port closed. I don’t plan to attempt closing a fourth port. And I may try to do a slug test to see when compression occurs with each. After I’m done I’ll decide if 2 ports or 3 is better for my use. If we are -3db at 15-16hz currently and didn’t lose any usable home performance id say this tuning is a winner. And maybe just a bit better with 3 if it doesn’t chuff.

I got his reply a day or two ago.

I used a rolled up T-shirt and capped it with duct tape. It’ll be fine for what I’m doing

Yes they are. Rockwool inside frames.

Did some experimenting today with the subwoofer. When it is tucked into its hole its size is very manageable. I forgot how massive it is when the behemoth is actually pulled out into the room. It makes the jubes look like bookshelves in person. 75” tv for reference. The measurements were takin from my middle couch seat 14ft from the subwoofer horn mouth. I did the initial peq using Chris’s thread. And did so with all ports open as they came from the factory. I’m uncertain what I’ve lost up top at the expense of lower performance at this point. And I’ll try to see if there is any room for optimization in the freq response with the second port closed. To keep things consistent I made sure not to move the mic or change any peq along the way. Id like to hear everyone’s opinions on this heresy.

The only issue with this is some people are seeking the k510 and are not needing a stand or driver.

Still loving this setup. No new changes worth mentioning.