Curved Geddes Abbey12 Build

[ColoradoTom]

Well, with all the threads about waveguides and curved builds I decided to make a semi-DIY attempt at my own version. Last February I was able to listen to a pair of Geddes Abbey 12's here in Denver and was truely impressed. I recently received a pair of baffles with the waveguides, crossover parts, and drivers (hence the semi-DIY). I was able to start on the build a little over a week ago after desigining a bending form and cutting and prepping stock and sheet goods. The sides and internal braces are 1 1/2 " laminated Balitc Birch plywood, MDF and a cherry veneer that I cut from some special boards I've been saving for this project. The birch, MDF, and cherry were laminated in a vacuum press using epoxy. The front baffle and the back will be a satin black enamel. The sides (cherry) will be a hand rubbed oil finish. All exposed corners will be rounded over to a minimum of 1 1/2 inch radius. Will keep people informed of the build if there is an interest.

ColoradoTom

[JonMarsh]

Sounds robust, and the cabinet work is looking very nice so far. Wouldn't expect anything less from you!

What goes in the guts of them? By all means, keep us informed!

~Jon

[fbov]

There is always interest in beauty... keep posting!

[ColoradoTom]

Sounds robust, and the cabinet work is looking very nice so far. Wouldn't expect anything less from you!

What goes in the guts of them? By all means, keep us informed!

~Jon

Hey Jon.......... Didn't expect to hear from you with your recent history of work schedule!! I should have started on this project a while ago, but my work has been similar to yours, which is a good thing since I have a daughter about to enter her senior year of high school and the cost of her college education is staggering but this year has made me breathe a little easier.

Details on the Abbey can be found here: http://www.gedlee.com/abbey.htm

The drivers are a B&C 12TBX100 woofer, a B&C DE250 compression driver and a 12" waveguide designed by Earl Geddes. They can play rather loud from ~80Hz on up 8O , but at the same time sounded similar to my Soundlab M1's. Uncompressed dynamics are addictive. The design requires multiple subs, so I am also working on a dual opposed sub design with similar astethics using my eight Aura 12" drivers. Hope you're getting some time off for the Holidays - I'm taking the rest of the month off and won't go back until after the first of the year

Tom

[ColoradoTom]

Something I probably should state is that Earl Geddes has not approved any of the design criteria that I'm using. I have calculated the volume and I'm within 5% of his stated values, which shouldn't cause any problems since he uses a sealed enclosure. I'm also using the same roundovers on all corners that he suggests in his kits.

I do plan on doing measurements as well as direct comparisons to the original design at a local site, so I can let people know how well I succeded in adding my own "spice" to the mix. I do know that the curved panels seem to be about as "dead" as the sides to my M8ta's........ and that's saying alot!!

Tom

[JonMarsh]

I do plan on doing measurements as well as direct comparisons to the original design at a local site, so I can let people know how well I succeded in adding my own "spice" to the mix. I do know that the curved panels seem to be about as "dead" as the sides to my M8ta's........ and that's saying alot!!

Tom

That's going to be interesting to hear about!

Things have been bezerkely this year, but easing off the last couple of months a bit- Friday will be my last work day for the month. And I have wood glued up and drivers coming in, and hope to get to play with the DSP license for my LIO-8 soon with the new Arvo hybrid/passive dipole. New Years or bust!

Several old friends are in the same situation as you- a gal who used to be our Marcom director in the good ole Siemens days is giddy because her daughter got into the school she wanted, and terrified because her daughter got in the school she wanted! Out of state, of course...

Enjoy your time off, and hope you make progress as well as enjoy the holiday!

[---k---]

Tom, Thanks for sharing. I would love to hear your impressions when you get them done.

As for all of you with children about to go off to college, I say let them pay for it themselves! I did in seven years. If you choose your major correct and your school correctly, it isn't an issue.

[ColoradoTom]

Tom, Thanks for sharing. I would love to hear your impressions when you get them done.

As for all of you with children about to go off to college, I say let them pay for it themselves! I did in seven years. If you choose your major correct and your school correctly, it isn't an issue.

Yup..... That was my original thinking. I paid my way through school and worked hard to get a TA job to get my Masters. My daughter wants to be an engineer and tuition at most engineering schools is >$30K and asking a kid to foot $120K of costs is probably not reasonable. She's looking at Cal Poly, Purdue, Colorado School of Mines, and Baylor. My wife and I are praying she'll get merit scholorships as she's in the top 5% of her high school class of 600+ students. With a second one right behind her I'm thinking this might be my last DIY project for a while!!!!!!

Tom

[---k---]

I can highly recommend Purdue Engineering. :T
Of course, when I went there, my in state tuition was $3900. It doesn't feel like it was that long ago.

[ColoradoTom]

Updates

Haven't been able to work on these until yesterday. Lots of family and friends activities.. and like Jon I had the flu during Christmas. Here are a couple of pictures of the dry fit from today. All the roundovers have been finished and the cabinets have been rough sanded. Just need to fit the internal braces, do the final glue-up and then sand and add the finish.

Tom

[Hdale85]

Those are looking gorgeous!

[---k---]

Looking good.

[JonMarsh]

Haven't been able to work on these until yesterday. Lots of family and friends activities.. and like Jon I had the flu during Christmas. Here are a couple of pictures of the dry fit from today. All the roundovers have been finished and the cabinets have been rough sanded. Just need to fit the internal braces, do the final glue-up and then sand and add the finish.

Tom

Dang! You're both productive and skilled! Whereas I am only demented and loquacious! :B

You're finishing six walls faster than I can muster one! Looking good as usually, Tom!

[ColoradoTom]

Weather and work are fighting against me... I was able to get the backs sprayed with truck bed liner and get the first coat of grey primer on before I had to get back to my day job! The fronts will be black when finished.

Hoping to get a couple of coats of varnish on over the oil this weekend. Starting to look better.

Tom

[Dean100]

Wow! Those are going to be very nice when done> :T You are a true craftsman.

[JonMarsh]

I understand the feeling of being sabotaged by other circumstances- having to tear down my building setup for the next few weeks, and heading out on travel. But on the bright side, tweeters shipped yesterday!

These are looking very good, Tom. Keep us posted when you make more progress.

[---k---]

Tom,
You're still making better progress then me. I've had all the parts for a pair of speakers for about two months now and zero saw dust. ops:

[ColoradoTom]

Tom,
You're still making better progress then me. I've had all the parts for a pair of speakers for about two months now and zero saw dust. ops:

Well, I'm starting to get into a deadline situation. I help coach my daughters girls tennis team and the season starts next month.... at which point my free time will go to just about zero. If these don't get finished by the end of January the'll be on hold until April! :cry:

[ColoradoTom]

I understand the feeling of being sabotaged by other circumstances- having to tear down my building setup for the next few weeks, and heading out on travel. But on the bright side, tweeters shipped yesterday!

These are looking very good, Tom. Keep us posted when you make more progress.

Yup..... work is good news/bad news. Good news is we're very busy, bad news is we're very busy!! 8O

If I can get one more decent day where I can open up my garage for a few hours and get the primer work finished I'll be home free.

Tom

[ColoradoTom]

Finished...........

I haven't been able to work on these for the last month due to some health issues with my oldest daughter.

Still working on setup and integration with my subs but they are really sounding good.

Tom

[---k---]

Wow. Just wow. I'm looking forward to hearing your listening comments. Hopefully you can compare and contrast them to some other designs.

[dar47]

Very nice! Are those grills over the wave guide I see?

[JonMarsh]

Now we've got some scale...

Look very nice, Tom- the picture puts some scale on how bit these are!





Looks like you're done your typical great job! Sorry to hear about health problems with your daughter.

The last month has been very busy, and this weekend I find myself out in Orlando for the start of the IEEE APEC conference- I'll be here until next Friday when I return.

Let us know more about what you think of them.

[Face]

Very nice! Are those grills over the wave guide I see?

No, that's a foam plug to reduce HOM distortion. http://www.gedlee.com/downloads/Soun...%20Systems.pdf

[ColoradoTom]

Look very nice, Tom- the picture puts some scale on how bit these are!





Looks like you're done your typical great job! Sorry to hear about health problems with your daughter.

The last month has been very busy, and this weekend I find myself out in Orlando for the start of the IEEE APEC conference- I'll be here until next Friday when I return.

Let us know more about what you think of them.

Thanks Jon, the speakers have about 10 coats of varnish on them......... it's been hard trying to rub them out as I'm doing all the work in my garage and the temp is always around 55 - 65 degrees. I may have to do some additional finish work on them this summer but I'm probably the only one that would notice.

I was afraid they wouldn't be solid enough.......... man was I wrong!! They must weigh close to 100lbs each!

Still collecting initial impressions, but one thing they do much better than the Soundlab speakers is dynamics. They can play extremely loud and do so with rapid and truely scary volume changes. The Soundlabs would peg my Pass X600's during moderate loud passages.... the Geddes Abbey's don't even move the amps out of class A. They sound SO clean at impossible volumes.... I'm really glad I didn't have speakers like this when I was young and in college!! The nice thing is that my options for power amps are much greater and I've moved my Audio Research VT200 back into the mix!

Looks like I may have to ponder upgrading my subs this summer to be able to keep up! Toying with the idea of buying six B&C 18TBW100's eighteen inch cones and putting them in three separate 150 liter dual opposed configured seal boxes. With room gain and plenty of power I may be looking at ~120dB at 15Hz :E

Tom

[dlneubec]

Beautiful work, Tom!

They are a huge step up from the painted rectangular box versions I've seen. What are the rough outside dimensions? Are you going to do some beefy stands for them?

[JimS]

wow, beautiful finish work Tom

[meb46]

Very nice work... some serious attention to detail!

[ColoradoTom]

Beautiful work, Tom!

They are a huge step up from the painted rectangular box versions I've seen. What are the rough outside dimensions? Are you going to do some beefy stands for them?

The dimensions are 17 inches wide, 30 inches tall, 15 inches deep and they taper to 12 inches wide in the back. All sides are a minimum of 1.5 inches thick composed of laminated baltic birch and MDF with a 1/8 inch solid cherry veneer. Additionally, the top and bottom have a 3/4 inch laminated solid cherry pieces. My best guess is the weigh between 85 to 95 lbs.

I currently have some stands that were designed as center channel stands for HT. They are usable, but I will be making some custom stands this Spring/Summer assuming I can get my current list of woodworking projects done for friends and family.

Tom

[JoshK]

Those look fantastic! I really need to finish my pair.

BTW, you mentioned Cal Poly. I am a Cal Poly alum (so is my father, but that was coincidence, not by design). I can't say enough good things about that school for undergraduate technical majors. Its cheap (for in state, but have her work for a year part-time during her first year and then the 3 years after will be in state). Its a fantastic place to go to school! The town is mostly college oriented but with enough other stuff to still be interesting. The prof's give lots of 1-on-1 and attention. Lots of practical teaching as well.

After Cal Poly (I was a stats/math major) I got into U of Chicago which is #1 in my field, so Cal Poly was not snubbed as a weaker school to do your undergrad. I still keep in touch with many of my professors, including one whom I meet up with regularly for dinner when he is in NYC (his daughters live there).

The only reservation I have is that California public universities are in a bad place right now, due to state budgets, and the profs are suffering for it, so morale is a bit low.

The weather and the community are awesome with lots of outdoor activities around. Unlike when I went to UC where going off campus was a suicide attempt.

[ColoradoTom]

Those look fantastic! I really need to finish my pair.

BTW, you mentioned Cal Poly. I am a Cal Poly alum (so is my father, but that was coincidence, not by design). I can't say enough good things about that school for undergraduate technical majors. Its cheap (for in state, but have her work for a year part-time during her first year and then the 3 years after will be in state). Its a fantastic place to go to school! The town is mostly college oriented but with enough other stuff to still be interesting. The prof's give lots of 1-on-1 and attention. Lots of practical teaching as well.

After Cal Poly (I was a stats/math major) I got into U of Chicago which is #1 in my field, so Cal Poly was not snubbed as a weaker school to do your undergrad. I still keep in touch with many of my professors, including one
whom I meet up with regularly for dinner when he is in NYC (his daughters live there).

The only reservation I have is that California public universities are in a bad place right now, due to state budgets, and the profs are suffering for it, so morale is a bit low.

The weather and the community are awesome with lots of outdoor activities around. Unlike when I went to UC where going off campus was a suicide attempt.

Thanks Josh.........

I'm hoping I'll have some time to start the "speaker placement optimization dance" with them this weekend. The speakers were just placed where the Soundlabs have been and I'm probably not hearing them at their best. I have a Behringer DCX2496 that I need to get out and start using with the subs to really start to get things dialed in!!

My daughter and I will be traveling to the Chicago area for school tours this Spring and hopefully out to Cal Poly in late Spring/early Summer. From a purly self centered point of view, I'd love it if she went to Cal Poly, as we have access to a residence in Santa Barbara and visits in the Winter would be a lot more enjoyable!

Keep us posted of your build.

Tom

[JoshK]

Further $.02 on engineering education.... engineering programs are hard, anywhere. Make sure the school of choice spends time, effort and care on their undergraduates too, not just pushes them off on TAs while focusing only on grad students. One of the reasons why I think Cal Poly is special. There is a place for the other type of institutions, namely going to grad school.

[Hank]

Tom, those are beautimous! Just how large are they?

[ColoradoTom]

The dimensions are 17 inches wide, 30 inches tall, 15 inches deep and they taper to 12 inches wide in the back. All sides are a minimum of 1.5 inches thick composed of laminated baltic birch and MDF with a 1/8 inch solid cherry veneer. Additionally, the top and bottom have a 3/4 inch laminated solid cherry pieces. My best guess is the weigh between 85 to 95 lbs.

They give my back a good workout! Pretty glad I had the hernia operation done a couple of years back!!!!

Tom

[djkest]

Looks awesome! Nice work.

[ColoradoTom]

Hey Guys..............

Sorry there's been no word from me. My girls were in a serious car accident last month (rear-ended at a stop light by a guy going about 45 mph). For obvious reasons, work on optimizing the speakers in the room has been pretty low on my priority list.

Things have been slowly getting back to normal... so last weekend I purchased a Behringer DCX2496 Ultradrive Pro. Over the next couple of weeks I'll be trying to tweek the integration of my subwoofers with the Abbey mains. As it stands now, these Abbeys to a lot of things right. I've had no desire to move my Soundlabs back into the system, and for me that's really saying alot.

Updates and room measurements to follow soon (I hope!)

Tom

[---k---]

Thanks for the update. Really sorry to hear about your girls. That's scary and definitely sucks. I hope they are doing better.

Although I know it is difficult to compare and contrast speakers, I'm eager to hear your thoughts on these.

[JonMarsh]

Really sorry to hear about the accident- I hope you're girls are recovering well, and the car is taken care of! DUI? How does someone hit someone at a stoplight at that kind of speed otherwise?

my sympathy goes out to you....

Bests regards,

Jon

[ColoradoTom]

Jon and Ryan,

Here’s a picture…. Not the sight you want to see when you drive up to get your kids. I initially thought it was just a fender bender! My youngest (passenger) has a fairly light build and she received a pretty good concussion from the airbag – couldn’t focus her eyes for almost two weeks. My oldest (driver) saw the whole thing unfold looking in the rearview mirror and (unfortunately) put up her arms to protect her face just before impact, something you don’t want to do with an airbag in the steering column. The airbag forced her right arm around to her side and she nuked her rotator cuff and has some pinched nerves causing problems in her arm. They were stopped at a stop light at 1:00 in the afternoon (in front of a Middle School no less) behind another car and both cars that were hit were pushed about 20 feet into the intersection by the driver that caused the accident. Since there is a clear line of sight for over 400 feet, and the stoplight had been red for more than 10 seconds, and both cars were completely stopped at the light, I can only assume that he was texting.

Tom

[JonMarsh]

TEXTING = Drunk Driving

Actually, maybe worse- you'd have to be almost passed out to screw up in the circumstances you describe for the accident, if you were drinking but otherwise trying to pay attention.

Rotator cuff injuries are no fun at all; hope with physical therapy over time it will sort itself out.

[Hdale85]

Wow, I had a guy rear end me about a month ago because he was reading a sign, luckily we were only going about 10mph and didn't do any damage. I hope your daughter's end up ok! And sue the pants off that guy! That's just nuts.

[zephyrtear]

Sorry to hear about this. I was rear ended once as well, but luckily there were no injuries. I hope they recover well.