GFelber
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Posts posted by GFelber
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I picked up an old pair of Cornwall cabinets that I used as a base to build a 3-way Cornscala and compared directly to a working Cornwall II. I was not happy with the former (sounded too bright), so I began a lengthy process of modifying to a 2-way design using various horns/waveguides and active Eq. This resulted in the need to build a new cabinet, but basically the same footprint and volume as the Cornwall. I settled on what I think is a very pleasant 2-way design using Crites CW1526C woofers and SEOS 18" waveguides with a BMS 4550 1" HF drivers crossed at 850 Hz. The active Eq is a pretty much a requirement based on the characteristics of the waveguide and driver combo, but the results are respectable to 20 KHz.
Here's an in-room measurement without room correction:
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2 hours ago, Schu said:
I meant to say fwiw... not fyi. My bad, I apologize.
No worries! Thanks.
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3 hours ago, Schu said:
Fyi... aged hearing to say... 14Hz means you can still hear more than 90% of the audible spectrum because frequency increases logarithmic, not linear.
Correct and primarily harmonics at that. My point was in response to the OP's desire for "bright high notes" and that ears may not be as sensitive.
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Without getting into a lengthy discussion about cap characteristics, tolerance, ESR (very important IMO), etc.. . I typically use the Dayton 1%, Solen, Sonicap, Jantzen, and Clarity caps and generally stick with the lesser priced series with 5% tolerance, where available, for each brand. More often than not, I'm using the Daytons, Solens and Sonicaps. Again, based on my experience (and ears), I've tried the oil impregnated, silver, gold, etc and couldn't differentiate. Some say the Sonicaps and Daytons are "bright", and based on your response above you may want to audition those. They're pretty inexpensive as well.
After my little experiments, I'm primarily using components based on design specs rather than perceived "audio" characteristics. Every now and then I do go back to the box o' fancy caps for a test though...
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I would suggest doing as Moray suggests and test several. It's pretty fun exercise as well. I've done this many times over the years (particularly when I was building crossovers for various projects and looking for caps for preamps) , including A-B-X testing with three friends, and none of us could readily identify any differences. Moreover, we couldn't even identify the same cap at a proportion that was better than chance.
Without know anything about the sensitivity and specificity of your ears or what type of musical presentation you prefer, I couldn't make a recommendation for you. Some say they prefer oil or wax caps for a more laid back presentation, but again I cannot distinguish.
Edit to add: My ears are 50 yrs young and I cannot hear above 14 KHz.
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3 hours ago, DizRotus said:
I don’t know. We might need to see more examples of your work. On second thought . . . hell yeah, your up to the challenge. I especially like the little suitcase. It’s about the size and shape of the Voxel sub I recently sent to @rockhound Any more photos and/or info about that? I look forward to seeing what you do with the La Scalas.
Thanks
The little briefcase sub was one of my first designs. It employs a Dayton 6 1/2" driver (DCS 165-4) and a Dayton 70W plate amp. The box is 12.5" x 16.75" x 5.75" and 0.47 cu ft with 1/2" MDF. Let me see if I can find some more pics and the measurement data.
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I think I'm up for the challenge. Below are some projects I built from scratch over the past few years:
Tubelab SSE (still underway)
uFonkens with Fostex drivers for the desktop
Little sub for the above resembling a briefcase
Small sub for the MBR matching our furniture.
In-ceiling 2-way for my brother's porch
Original Cornscala
Revised 2-way Cornscala
Cubo 15
Two-way loudspeakers with ScanSpeak drivers for the MBR
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1 hour ago, Dave A said:
There was a kit at one time for those braces and it would be what I would do too even if I had to make them myself. If I ever own another set of La Scalas they will be ones I build out of 1" Baltic Birch. My experience has been they will resonate at higher volumes and everyone I know who has these will play them that loud on occasion.
Best set I ever had was one piece LSI with Al edge trim and fiberglass. They did not resonate even when played loud enough to physically thump your body 12 feet away.
Thanks for the input and welcome all! I think I've found one song, quite by accident, that will resonate these cabs at an appreciable volume (> 50 w).
I'm sort of noodling the Al edge, or even Al channel on the bins per one of the other threads. I could go with something I've not seen done such as steel angle and channel to frame the front of the cabinets with a medium to dark veneer, but not sure how that would look. I'm pretty the metal would add sufficient stiffness to the edges of the cabinets, but they may still resonate. Adding fiberglass would dampen the sides further. I'm still a little unclear on the effect of adding braces for stiffness vs. material resonance. The former will very likely mitigate the pesky LF resonance and shift to perhaps a higher resonant frequency that has less energy and cannot be heard. However, I'm favoring the look of the LS II-like clone (cant' fix the doghouse though) with the 1/4" birch ply wrap (glued and fastened very well), high-end veneer, and add the braces if necessary.
I've been reading some publications on exciters used to measure cabinet resonance and may choose to do an experiment of sorts with different materials and thickness clamped to the sides of the bin. It seems that the best way to measure this is with accelerators and/or lasers, but I'm not going to invest in that for one pair of loudspeakers. I think I may be able to use an exciter and SPL measurements only as a guide to find the resonance and may be a fun little project.
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6 minutes ago, Schu said:
Ask yourself firstly... "how loud do I really listen"?
Loud occasionally, but that's the exception. My motivations for this project are: 1. to update the LS1s in the best and most reasonable manner possible and 2; aesthetics so they can be "accepted" in the house
I should have added that I'll be incorporating a sub or two as well, most likely THT or Table Tuba(s), so the low end will be covered by these. Hmm... maybe I just answered my question.
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1 hour ago, jason str said:
1/4" ply over the 3/4 will not stiffen the cabinet much at all, its just not the same as 1" material though you would think so.
Bracing is really the way to make it right, might be a bit more work but worth the time and be sure to brace the inside of the cabinet ( where the woofer is) as well so you have bracing all the way from one side to the other.
That's a good point, but is it stiffness that's key here or absorbing resonant frequencies? That is, isn't it the case that birch plywood is stiffer than MDF for given thickness but likely resonates more at is has less mass? Would adding MDF to plywood work or would braces suffice?
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Greetings all,
New member and long time Klipsch enthusiast/owner (Heresy's, Corwalls, La Scala and Cornscala) new residing in Montana.
In December I picked up a pair of 1985 birch LS1s for a bargain and they're in pretty decent condition. They have a few nicks and scuffs and some odd holes drilled into the bottom of the bass bin that looks like they were mounted on stands, so I plan on re-veneering with something like walnut or perhaps a more exotic species. Last month I ordered the AL-4 upgrades from Klipsch and I also picked up a pair of the MAHL tweeter lenses and DE-120s to try. Too bad I pulled the trigger before the walnut varieties came out!
At any rate, my question is regarding the cabinets. In order to get these from the garage to the house (and please the Mrs), I am considering three options and would like feedback:
- Simple (still a challenge) re-veneer perhaps grills as these do not have any and prefer the look.
- Adding 1/4" birch ply just to the sides of the cabinets and re-veneer, + grills. I would also veneer the front of the horn motor boards and then add 3/4" trim to frame the grills so it would be difficult to tell these were any different from stock other than the ticker walls on the bass bin.
- Separating the tops from the bottom bins, building the top hats, and adding 1/4" ply and veneer to closely match the LS IIs. This would obviously be a lot more work with little gain compared to #2 above, but I really like the looks of the IIs.
Seems like #2 would be the best bang for the buck and would stiffen the bass bin a bit, but once I start adding wood and veenering, should I go all out and do #3 or just do #1 and call it a day...or week?
Thanks much,Gene
Mr. Weiner's Null Tester for wires
in Technical/Restorations
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Or capacitor selection & evaluation