LCR's in Birds Eye Maple

Brian Bunge · « **on:** 17 Sep 2005, 02:37 pm »

These are 3 LCR's I built for a customer in birds eye maple veneer with separate crossover boxes and with magnetic grills.

Please let me know what you think.

bald · « **Reply #1 on:** 17 Sep 2005, 05:28 pm »

Looks good.

I'm confused by the grills. It looks like a solid piece with some substantial thickness that would butt right up against the driver edge? Is that what it does or am I confused by the picture. I'd be under the impression that would be fairly undesirable after going to all the work to flush mount a driver.

bald

ABlakeG · « **Reply #2 on:** 17 Sep 2005, 07:58 pm »

Man, those look great -- even better sitting in my living room waiting for me to finish my room.

Everyone who has come over to my house has commented on the finish Brian. You did a great job on them.

Now where are my grills???????????

Thanks

Blake

Brian Bunge · « **Reply #3 on:** 17 Sep 2005, 10:33 pm »

The grills are 3/4" MDF. I cut out holes the size of the woofer frames and the size of the through holes for the tweeter and mid. I already had to make the cabinet 1" wider in order to even be able to wrap the veneer and still be able to fit grills. The grooves cut for the rubber spline that holds the grill cloth in place are 1/2" from the top and bottom (or sides depending on the orientation) edges of the frame. It would have been nice to have just a "frame" for the grill cloth to be stretched around but I was concerned about the strength of the frame over time. And for the record, my cabinet, veneering, and finishing skills far exceed my grill making skills. So I was pretty damn happy with the turnout!

Blake,

Glad to hear you are getting so many compliments on the speakers. Your grills went out on Wednesday and are scheduled to arrive this coming Wednesday. I shipped them to your work address this time!

bald · « **Reply #4 on:** 17 Sep 2005, 10:45 pm »

Quote from: Brian Bunge

The grills are 3/4" MDF. I cut out holes the size of the woofer frames and the size of the through holes for the tweeter and mid. I already had to make the cabinet 1" wider in order to even be able to wrap the veneer and still be able to fit grills. The grooves cut for the rubber spline that holds the grill cloth in place are 1/2" from the top and bottom (or sides depending on the orientation) edges of the frame. It would have been nice to have just a "frame" for the grill cloth to be stretched around b ...

Maybe Kevin can comment, but it seems to me having 3/4" MDF surrounding the drivers like that would affect the diffractive properties of the speaker. Maybe not, I don't design crossovers.

bald

ABlakeG · « **Reply #5 on:** 18 Sep 2005, 12:24 am »

Quote

Maybe Kevin can comment, but it seems to me having 3/4" MDF surrounding the drivers like that would affect the diffractive properties of the speaker. Maybe not, I don't design crossovers.

I see your point there... I wanted grills for another reason, though. These three speakers are all going to be oriented horizontally (that is how Dan Wiggins said they would sound best) and therefore are in the poking range of my nephew (and my future kids). This is more a deterrant than anything. So if it affects the sound, I am not too concerned as they will be off most of the time.

Blake

Kevin Haskins · « **Reply #6 on:** 18 Sep 2005, 03:57 pm »

All grills effect the performance. How much depends on a lot of factors but anything you stick out in front of the drivers a couple inches is going to give you early diffractive effects. You can design the speakers with grills installed but it is not desirable in terms of performance. All of our designs are based upon not having a grill. If you need to use a grill give as much unobstructed space around the midrange & tweeter as possible. The Extremis have a lot more travel than a typical driver so you have to keep an eye on clearance with them also. You just have to live with the problems if you need to use a grill.

Kyle R. · « **Reply #7 on:** 19 Sep 2005, 05:23 pm »

The nice thing about those grills on those is the fact that they are held in place by magnets so it will be easy to install or remove them.

I'm glad you are pleased with them Blake!

kfr01 · « **Reply #8 on:** 30 Sep 2005, 02:07 pm »

Are there any potentially audible disadvantages from making an external crossover box like the one Brian made? Not that Brian's will have any problems .... but are there any potential probelms with this, in theory?

Hate to be a bore, but I actually like the concept. It would allow easier tweaking, etc. later while keeping the active xo route open.

Question 2: Kevin, since my build time has been longer than anticipated, I'm just wondering about the status of the PCB's... ?

Thanks!

Kevin Haskins · « **Reply #9 on:** 30 Sep 2005, 02:11 pm »

Quote from: kfr01

Are there any potentially audible disadvantages from making an external crossover box like the one Brian made?

Not that Brian's will have any problems .... but are there any potential probelms with this, in theory?

Hate to be a bore, but I actually like the concept. Would allow easier tweaking, etc. later while keeping the active xo route open.

The external crossover only has advantages in my opinion. I guess cost would be a downside and the fact that you have another box to place in the living area.

Al Garay · « **Reply #10 on:** 1 Oct 2005, 03:43 am »

Not to be a devil's advocate but the LCR cabinets are plenty big for putting the crossover boards inside, securely and within reach for removals (esp using industrial velcro). External crossovers are handy, easy access, no having to remove the drivers or even move the speaker cabients. But it's not like dealing with internal crossover's is a problem.

PCB boards are also nice, less likely to make a connection error but if you take your time, you will be able to solve the crossover problems and learn along the way.

It depends on what type of a journey you want... like climbing a mountain with the help of a Sherpa or packing light and doing it yourself.

By the way, the LCRs are really worth every bit of effort you put into them. They sound excellent (dynamic, open, detailed in mids and extended highs, very large soundstage esp in height and depth, very good horizontal and vertical dispersions, low bass). The best among the Adire/Exodus kits I have tried (Kit 41, 61, 641, 261 and LCR) but still waiting to build the Kit2641.

DIY takes time.

kfr01 · « **Reply #11 on:** 1 Oct 2005, 02:14 pm »

I surely understand that DIY takes time.

I'm not working on LCR's, but the 4 2641 cabs in my garage are just screaming to be finished.

But lack of patience isn't my motivation for the external crossover route. I simply see myself going to at least partially an active digitial crossover / eq sometime in the future, and would like (1) the crossover very easily accessible and (2) 3 binding posts already on each speaker.

Anyway, it is just something I am thinking about doing ... the front baffles are on deck to be cut this weekend. The crossover construction should happen sometime this week, if time allows.

Al Garay · « **Reply #12 on:** 3 Oct 2005, 01:47 am »

What are you going to use for center channel?

Are you thinking of going active for a pair of Kit2641 (3-way with 6 channels of amplification) or fully active for multi channel system (that's ambitious).

Kevin Haskins · « **Reply #13 on:** 3 Oct 2005, 02:27 am »

Quote from: Al Garay

What are you going to use for center channel?

Are you thinking of going active for a pair of Kit2641 (3-way with 6 channels of amplification) or fully active for multi channel system (that's ambitious).

I actually have an active crossover designed for both the 2641 & the LCR. I just need to get some time to build and measure the completed system.

bald · « **Reply #14 on:** 3 Oct 2005, 02:40 am »

Quote from: Al Garay

What are you going to use for center channel?

Are you thinking of going active for a pair of Kit2641 (3-way with 6 channels of amplification) or fully active for multi channel system (that's ambitious).

He actually is just doing a 2-ch 2641 setup. The other pair of 2641's is going into my HT. I have an energy cc-1 that is holding me over until I decide if I need an LCR to go along with them.

bald

kfr01 · « **Reply #15 on:** 3 Oct 2005, 03:22 pm »

Yep. I'm basically just a two-channel guy. No, I'm thinking of someday going active on the cross between the extremis pair and the css wr125. I also have clumsy hands and not much patience.

The external xo seems like a good fit for me.

kfr01 · « **Reply #16 on:** 4 Oct 2005, 05:27 pm »

Alright. I just built some FR125S based speakers and I got the painting thing down. I will never try a semi-gloss black paint job again. I simply don't have enough patience or the right tools.

So, it is time to try laminate or veneer for the much larger 2641 speakers.

My stupid question:

Do you apply the veneer to the front baffle before you cut the driver recesses? I trust my Jasper jig a lot more than I trust my clumsy hand with an exacto knife later.

It'd be nice to use a laminate bit with a bearing on the tip, but the recesses aren't quite deep enough to allow for bearing-tipped router bits.

Thanks!

Kevin Haskins · « **Reply #17 on:** 4 Oct 2005, 06:06 pm »

I'm no veneering guru but I prefer to do the fronts and then cut the holes. You get a very nice finished job. Just make sure you use a good sharp router bit and cover the front of the speaker with that clear stick-on shelf liner to prevent scratching the finish with the circle jig.

Cut the recess first. I often have to make a couple passes to get it wide enough. You can use larger than a 1/4" bit and just calculate the hole size when using the larger bit. Practice on a scrap peice before you actually try cutting the speaker hole. Once you get it dialed in on the scrap for both debth and diameter you can then do your finished speaker cabinet. Cut all the holes of the same size at the same time. If you change your plunge router debth or size it is difficult to get it set the same way again and your other speaker will not match exactly. It's just like making good cuts on the table saw. I set it to one dimension and then cut all the pieces with that dimension at one time. That way all the pieces match exactly assuming you are using good cutting technique.

Brian Bunge · « **Reply #18 on:** 4 Oct 2005, 06:33 pm »

I much prefer to cut the driver recesses and through holes before attaching the baffle and veneering. I use a laminate trimmer with several different trim bits to cut the veneer flush on the driver recesses.

This is how I'm doing the current 2641's that I'm building (rest of the drivers arrived this weekend, Thanks Kevin!). I use scrap MDF to do test cuts, making sure the diameter and depth of the recess are right before cutting my baffles. I use a 3/4" straight bit to cut the recesses and then go back with a 1/4" spiral up-cut bit to cut the through holes. With the 3/4" bit, simply subtract 1/2" from the diameter you need to cut and place your pivot pin there. For instance, the Extremis requires a 7" diameter recess. If I cut it with the 3/4" bit, I simply place my pivot pin in the 6 1/2" hole on the Jasper jig. The jig is calibrated for a 1/4" bit, so any change in bit diameter must be accounted for.

kfr01 · « **Reply #19 on:** 4 Oct 2005, 07:44 pm »

Brian & Kevin:

Thanks for the tips. So, Brian veneers after cutting the driver holes and Kevin cuts the driver holes after finishing.

The X-factor here seems to be the laminate trimmer with several different trim bits. Brian: could you be a bit (pardon the pun) more specific here? Is a laminate trimmer a separate product from a router with a laminate bit?

Thanks for the help!