Marvel

Don't you still have about four months before the ice goes out? []

I haven't actually checked with Klipsch about it yet. My youngest is headed to Europe for an orchestra tour in May, and it's $3200. So....between that and a couple of other things going on in my life, the cash isn't there. My plans are always bigger than my wallet! [*-)]

With a quick calculation it should fit on one sheet. And if you would rather do a slotted port, Dennis gave me these figures: The vented LaScala as I described runs to about 4.8 cu ft net. Two 4" ID by 7.25" long ports gives an Fb=35hz. A 15" by 1" port would need to be about 5" long for a 35hz Fb. A 13" by 2" port would need to be about 8-7/8" long for a 35hz Fb. A 15" by 2" port would need to be about 10-5/8" long for a 35hz Fb It helps to have a good software port model, the long narrow aspect ratio requires a different length than the same area in a square or round port. It also helps to start out a bit long, and trim it shorter to reach your target Fb.

Have a read... they worked out some wiring issues, etc. I am really wanyting to do this myself. http://forums.klipsch.com/forums/t/100889.aspx?PageIndex=1

Pete Fowler and his buddy built a new set of cabs with the added space. Testing, they came up with the following figures (I think with no eq filter between the pre and power amp): 200 160 125 100 80 63 50 40 31 25 20 HZ 77 80 79 73 72 78 68 60 61 52 51 dB Stock, mouth braced 76 78 78 73 69 75 65 60 66 56 52 4.5 cuft, no ports 76 78 77 75 74 80 70 60 68 54 54 Two 4"dia 10" ports 76 79 78 76 75 80 71 60 68 54 53 Ports cut to 7" The interesting thing with 10" ports is the boxes went deep, but the snappy, fast horn sound was lost! Cutting the port length to 7" brought the snap and speed back to same as stock, plus the lows remained, esp. at the 31Hz box tuning point. This data is with K33E driver and light stuffing. We think a K43E in this box would be superb, but haven't tried it yet. Neither of us is going back to stock. Pete

Speakerfritz, This is for all the cowards out there who would like to hear what it sounds like without putting any marks on their present cabinets. Also, some have said they wanted to raise up the cabinet some. This is ten inches, which to me would make them too high. Of course, since most people don't have their LS all the way against the wall, you could adjust the depth and lower it some. If you don't like round ports, you could do a slotted port as well. I might find that more attractive. Here is the mod done to the top:

Without a filter between the pre and power amp, Dennis says the bass can sound a bit lean. " The net volume was found to be correct for 6th order tuning for the K43 woofer (B6) or quasi 6th order tuning (C6) for the K33 woofer (in the stock LaScala). Vents are typically two 4" diameter by 7"~10" long. Longer is tuned lower, in general the larger magnet woofer can handle the lower tuning. Boost is applied ahead of the amplifier and is usually Q=2 at Fb. Fb is sort of experimental with the smaller magnet woofer liking the shorter ports. [i.e., the K43 could use the 10 inch ports, while the K33 works better with the 7 to 7.5 inch ports] Part of this has to do with room modes. The small sized bass horn does nothing below about 100hz, but floor to ceiling gives us boost in the 70hz~75hz region (7-1/2'~8'), and wall to wall (short wall) in the 47hz~51hz region (11'~12'). An Fb around 31hz~35hz seems to work best with these room sizes and speakers. If you have an actual wall for the third wall (most newer homes don't, they have a large opening into a 'dining' area) and it is around 16'~20', you may have to lower the Q of the boost. It should be pointed out that most recordings are rolled off in this area and a little extra boost is nice."

Here are the basics, gathered from some users who have built this mod to the La Scala bass bin. thanks to djk for all the design, input and figures. First, let's assume you only want to try this out and not make any permanent changes to your precious LS cabinets. Sounds fair to me. Build a box to go underneath the cabinet, after first removing the bottom cover. This box will have a matching opening to mate with the LS bottom, and two ports, using 4 inch pvc for your favorite building supply store (Home Depot, Lowes, Menard's, etc). Considering the LS is about 125 pounds, I certainly wouldn't use anything less than 3/4 inch. Dennis says this for the size: "I'm looking for a total net volume of about 4.8 cu ft. I figure the stock back volume is about 2.25 cu ft. Call it an internal height of about 9" (22.5 X 22.5 X 8.70 = 4404 cu in = 2.55 cu ft). Two 4" ID by 10" long ports displace about .15 cu ft so 10" outside is close enough." Comments made by some folks who have built this, have lead them to shorten the ports to around 7 inches. This retains the snappiness of the horn but gives the lower bass. Here's a simple drawing:

wrinkles - I'll start another thread for this... so this one won't stray too much more off course. Bruce

I have most of the data that Dennis posted about the bass mod, including the filter at the front of the power amp. Nice to do that on the Crown... I made the 3D drawing of the mod, and can give you dimensions, but it is just a box with the ports in it. Three quarter inch material (mdf or ply), ten inches tall, to match the width and depth of the LS. You have the port sizes to go with it. I'll dig out the details and email them to you. Bruce

Stan, I would love to stop by and hear JC's LSIIs, because I have an older pair of LS, powered by 3.5 watt SET amps and find them wonderful for classical music. My younger son, a junior composition major at Valparaiso U. in Indiana, thinks the ones we have are great, and has made the comment that he feels he is siting in front of an orchestra. I don't use a sub with mine. He's a trumpet player too, so he appreciates the attack and dynamics of what I have. From what everyone has said, the LSII is a huge improvement over the older model. Plus, the looks are killer compared to the Klipschorn Jubilees with the K402 horn on top. Is a high WAF important? I don't doubt for a second that the Jubes are better (or the regular Khorn for that matter). Bruce

Wrinkles, If you need any of the info on the bass mod, let me know. I have a folder with most of the info in it. Bruce

DD, That's a PAudio woofer, and right now they have it for $70 (I had loked at the ten incher by mistake). Bruce

Cowboy Junkies -very depressing... Most classical music I find very uplifting. Some has extreme melancholia attached... not for rainy days when you are by yourself.

I might be hard to get all the black off, but that is still a good price if they are in good shape. Sounds great for the Heresies.

Neo, I would say good prices for both. If the LS are in good shape, you could have them refinished (assuming you wouldn't do it yourself). A set or Cherry Heresies would be nice... not a bad price if they are in good shape.

I thought you liked that hotel lobby carpet look.... [:^)]

Just to be clear, the original LS is 3/4 inch plywood and the new one is 1 inch MDF. Bruce

Neo, Amy said they have three pairs of the 60th models... returned for some reason. They have had the testing, yada yada... Heard a pair o 60th Anniversay Khorns in Indy last June. Pretty awesome sounding speakers.

I like this Pike's Peak climb by Ari Vatanen. NO guardrails at all and mostly dirt. I have this on my pc as a 60meg download I found.This will open in a new window. http://video.google.com/videoplay?docid=-6604540639943123451

The zener might introduce some noise into the system. A voltage divider made with resistors would work, but you will dissipate some heat trhough the resistors. The is what a cheap (or not so cheap) volume control does. If it is a DC fan, you can usually slow them way down using a PWM supply. This is what model trains use. The full 24 volts would be applied to the fan, but in pulses. For it to recieve the equiv. of 12 volts, it is only on 50% of the time. This could also introduce noise. Computer power supplies operate this way, but for set voltages.

Here, here!!! I couldn't agree more, Max.

They have some nice little kits if you like solid state and op amps. They have an A/C power supply you can get for the phono pre, which provides ±15VDC. Be nice in a small box. Maybe a chocolate box.

Passives with high end parts could run over $1000 for the pair (Rigma spent about $1200). They could be built for less.

ART pro audio has a similar device, but they don't list the complete specs on their site. The ART product has a few other features, like optical I/O from the usb bus. The version 2 can be had for around $100 or less. http://www.zzounds.com/item--ARTUSBPHONOPLUSV2 They also make the CLEANBOX that some of the guys on here are using.