Cornwall Riser

[dbflash]

What exactly is the purpose of the riser on the Cornwall?

Was it to get the tweeter and mid range 2 inches higher which is getting them closer to ear level when sitting down?

Was it to act as spikes for the speaker?

The reason I ask this is I added new binding posts to my Cornwalls. While I had the cabinets open I also rewired them. Monday night I started this. I changed the first speakers binding post, added new wire for the input and changed the midrange wire. It was late and I thought Id wait until Tuesday to finish. After I put everything back I fired up my amps and made sure the speaker was still working. I only put 2 screws back in to the rear panel. I put a CD in and it worked.

Tuesday morning I was listening to a CD and went behind the speaker to look at the binding posts to see how they looked in daylight. The back panel was really vibrating.

Tuesday night I finished both speakers. I put everything back together. I powered up my system. The rewire made a big improvement. More bass and cleaner hi's.

This morning I was thinking that if I got the tweeters at ear level my system would sound even better. When I was using my Lascalas I built stands for them. The stands were basically a platform, filled with sand. I then added legs to the platform. I got cleaner and tighter bass. I am thinking about just building the platforms and setting the Cornwalls on them. This would get the speakers 5 higher. I am also going to add another ¾ piece of plywood on the rear panel. I could not believe the energy inside the speaker. I am using a 3.5W amp. My volume control on my preamp is off at 6:00. I was listening with the volume control set at about 8:00.

Thanks,

Danny

[Good2BHome]

Danny,

Your thoughts on what a riser will do are correct, however the 2" height is the correct height. The higher you make them above 2 " the more you risk losing bass.

I built 2 1/8" (a function of 3 layers of 3/4" plywood) risers and filled the middle with a combination of #9 shot and tire weights to obtain a weight of 60 lbs. per riser. I am pleased with the result. The mids and highs became tighter and the image was improved beyond just raising the speakers 2 1/8"(i.e. to ear level).

They are bolted to the bottom of the speaker. Just setting the speakers to top of a riser, I don't believe would give the same result IMHO.

By the way, I would do it again. If I ever sell these Cornwalls I will remove and put these risers on the "new" Cornwalls.

Additional Information: I've heard that tilting the speakers up at 22.5 degrees will couple (acoustically) the speakers better to the floor and improve the bass. This would be done by retaining the 2" front and reducing the back. Maybe others can comment.

Mike

[mobile homeless]

I do believe the tilt is not originally for coupling, but an attempt at time alignment of the drivers.

btw, what wire did you use to rewire your CW, Danny?

kh

[dbflash]

Mike,

Thanks.

I'm thinking about taking the risers off and build my 5" platform (2x4 on edge and 2 pieces of 3/4" plywood packed with sand.

When you added your platform did you notice a deeper and tighter bass?

Danny

[dbflash]

Mobile,

I had some DH Labs Silver Sonic T14 speaker wire.

I will leave this combo in for awhile.

I'm thinking that if I use a solid platform I will get better bass. The sound has improved alot after the rewire. If my speakers were on a concrete slab I would not worry about this, but my house is a 1 story with no basement.

I have also noticed that if I raise myself up in my chair in the sweet spot I get a even better sound. That's why I'm thinking about raising the speakers a tad. That would seem to me to be the same thing as tilting the speaker's back.

Dean was also correct when he said he lost the warmth of his system after he rewired his speakers using silver wire. I was using a pair of Nordust Red Dawns between my CD and pre amp. I changed that out last night with my superlatives which returned the "warmth". I am also using Alpha Core AG1 speaker wire. I think I have maxed out on silver.

My system sounds very good. I'm just having fun tweaking now.

Oh yea, this morning I put my Rega back in, which replaced my Heart. With my present configuration It sounds better. Before I rewired I liked the Heart better.

Danny

[HDBRbuilder]

Actually, the original intent of the riser(not the slant riser) was to act as a sort of "toe-kick" to save the cabinet from scuffs and damage when vacuuming, etc...around it. It also acted as a means to get the bottom of the speaker cabinet off the floor, in order to provide for some bit of airflow and to keep the bottom finish from adverse effects of humidity in carpets. In some situations a riser is sonically beneficial, thus the advent of the slant riser...in other situations the riser is sonically not of any benefit...it all depends on the listening environment, the postioning of the speaker, and the position of the listener's ears!

[edster00]

I love this BB...NOT! I typed a whole message and my post was blank except my signature when it showed up??

Here it is again:

Danny,

I made risers for my Cornwalls just like you are describing and I found that it did improve the bass response.

You said:

"I have also noticed that if I raise myself up in my chair in the sweet spot I get a even better sound. That's why I'm thinking about raising the speakers a tad."

I believe that if you raise your speakers higher than they are now you will have to raise your chair even higher to achieve the same effect. Once I put my Cornwalls on risers I built taller risers for my chairs also, to put my head/ears closer to the same horizontal plane as the squawker/tweeter.

[Deang]

I'm getting good synergy with silver inside the box and copper on the outside. I think the silver in the box is a must do.

Seems to me the easiest way to make a weighted riser is just to make good use of the one already attached to the bottom of the speaker. Cut two pieces of MDF that would fit into the inside edge, and make the fit good enough so that they have to be wedged in. One would be pushed flush with the bottom of the cabinet, the other would act as the bottom 'plate' -- and would get tribond around the edges to keep it in place. A tight fit would act as a natural clamp so the glue would take hold better. When dry, I would drill a hole, pour in lead shot until full, and then plug the hole. What can I say -- I'm lazy.

[NOSValves]

Dean,

What silver are you using ? Not that I would ever go the wire route I know you have posted this before but my mind just never retains such things !

Craig

[Deang]

I went on the cheap. I used the silver plated stuff from www.northcreekmusic.com You can find it under 'accessories'. It definitely cleaned up the treble on the Cornwalls. This stuff is sweet, and goes for a mere .45 a foot.

I don't know if the cable is really that good, or if the old Copper in the Cornwalls was just that bad. Probably a little of both. I know silver plated speaker cable doesn't get the greatest reviews -- but this is being used on the other side of the crossover, with runs 2 feet or less. I think the main thing here is getting it done -- and then never having to think about the damn wire in the box again. It sure ain't going to turn green.

[Good2BHome]

Danny,

You ask if the 60 lb. risers improved the bass. Indirectly they did.

I did the tweaks covered in a previous post titled "Revealed: Secret Cornwall Mods at DFW Forum" There was a significant improvement in the bass. The risers were added after the tweaks were completed.

The effect of the heavy risers was to couple the speakers to the slab foundation. Now when you hear the bass you feel the bass!!

Hope this helps.

Mike

[Deang]

I suck working with wood, can't I just sit a couple of my kids on top of the Cornwalls while I listen?

[HDBRbuilder]

Dean,

If you did that, you could just change your signature to read: "1974 kid-butt damped Cornwalls."

[dbflash]

This was a busy weekend so I didnt have a chance to work on the stereo.

I thought about what my next up grade will:

I have to build another Flexy Rack for my bedroom system, so while I am cutting plywood I am going to build new risers for my Cornwalls..

I am going to take off the existing risers. I am going to build new platforms consisting of ¾ birch plywood and 2x4s. I will them pack them full of sand. After the platforms are built this will raise the speakers 5 inches. The tweeters will now be 3 inches higher then they were with the stock risers.

I am going to build the platforms the same size as the speakers and not the risers. I am also thinking about using the existing holes to add spikes. I have read mixed things about this. this will be the final mod when I have nothing to do.

After I listen to them for a week or two I will then do the Rope Caulk mod.

The final mod will be to add the extra bracing inside the cabinets and ¾ plywood to the existing back.

I also put my Nordust Red Dawns back into the system Friday night. I only had about 30 hours of burn time in them. I have been running my CD player non stop since Friday. Friday they sounded brittle and a little bright. This morning they are sounding warmer. I will let them burn for the rest of the week and see what happens.

Danny

[garymd]

Sorry to jump in with an unrelated topic but this is my first time in the forum and I didn't know how to ask a question on my own. I have a pair of 1980 cornwalls and recently had a chimney fire in the room which they reside. I reluctently let an electronics restoration company take them to assess the damage and was not happy with the care they took to load them in their truck. They still work fine but had a 1/8 inch of soot covering them. All is currently original and I'm wondering if I should just let them get cleaned and returned or should I let them try to replace any parts. The cabinets were not damaged and I think with a good cleaning they'll look as they always have - beautiful. Am I the only one out there with Zebrawood Cornwalls? I have never heard anyone else speak of zebrawood. They're incredibly beautiful and I'm pretty freaked out about leaving them in someone else's hands. Any advice other than get them back ASAP?

BTW - I predict that sometime in 2004, I will get a free pair of Khorns and by 2005 I will be running 3 different systems with various tube amps/preamps, spend almost a month's salary on a turntable, take 2 hour lunch breaks to scour thrift shops for used vinyl, own over 500 jazz albums and become another victim of the money sucking, time consuming, loon-filled Klipsch forum.

[dbflash]

Gary,

Welcome.

I would get them back.

If they still play fine, you can clean the components yourself.

Did you have the grill covers on? You may have to take the back cover off use a shop vac to get some of the grime out.

I think you can do this. I would baby those.

Or you can sell them to me for $250, since they are covered in soot.

Ask questions, you will get alot of answer's.

Danny

[HDBRbuilder]

All they probably needed was a good blowing-off with medium-strength compressed air, then a wiping-down of the cabinets with wood soap. Also the removal of the backs and a blowing out of anything that may have made it in through the port openings. If you were concerned with the way they loaded them up when taking them...while doing it RIGHT IN FRONT OF YOU...the prudent thing MAY have been to NOT let them take them! IMHO!! Zebrawood is one of the more rare of the veneers used on Cornwalls...with rosewood, mahoghany, and black walnut having been built in larger numbers progressively in that order. Zebrawood was probably rarer than teak, too...or about the same! I certainly would not have let them take them if I had been concerned with the way they LOADED them! But that is just ME.

BTW...it is highly likely that your Cornwalls(1980) were built by me...you may find my builder code on the back of them stamped into (normally) the rear edge of the upper left side as you face the rear of the cabinet. There should be two codes on them...one for ths sander and one for the builder team. If you find a one or two letter code with an "A" in it, then it was built by me and my helper. If my code is on one of them, then I built both of them, since we built mitered ones up in matched pairs.

Either way, let us know how things turn out.

[garymd]

Thanks. I'm usually not a stupid person but I may have been today. I called and they are going to gently clean the grills and the cabinets and give them back to me. I was cringing the entire time watching them being loaded into the truck. I bought them new in July 1980 but they may be '79 vintage. Thanks for your feedback.

[HDBRbuilder]

Well, Gary...I was the main builder for them (well over 90% of all of em) from early 1977 until September of 1983...so you SHOULD find my code, unless the sander sanded it off when evening-up the rear edges at the corner there...we built em flushing the front veneered edges at the miter joint, and sometimes a rear edge was a bit "proud" at the miter, so it was sanded flush with the other edge at the miter joint...sometimes deleting our stamped-in builder code or making it difficult to make out.

[Audible Nectar]

Interesting HDBR. I just checked my new-found 1976 Cornwalls and they show code letters "OD". Guess mine were a bit before you were doing the Cornwalls. You were sure right about the build quality - it's night and day vs. my '88 Corns. Built like a brick..........you get the idea!

BTW, you must absolutely see the woodworking job done on my '76 Corns. The owner was a woodworker, and he made these look like absolute jewels. I don't have a digital camera (I'm trying to borrow one) but these would impress even you.

Risers: Now I'm wondering about the risers on those '76 Corns....the risers given to me with these are 5" high and made with a brass plate look. Now that I read about the risers, I am wondering if this will be an issue. I haven't hooked these up yet, but there seemed to be no lack of bass in the owners home - that's for sure.