LECBOS Buyout MTM $120/pair

[LouC]

I've finished up the LECBOS build (includes a BOM). Added some text and new pictures to my webpage: LECBOS (http://www.lonesaguaro.com/speakers/GarageMTM/Lecbos.html)

July 5 - I bumped the padding resistor for on wall mounting. Added some pictures of the final setup, and a bit more to the write-up.

http://www.lonesaguaro.com/speakers/GarageMTM/FinBoxPost.jpg

[Mark65]

Can't wait to see and hear 'em in person!:D

Mark

[Thezeek]

Ah yes! Another cool build form Lou. I have a set of those tweeters to use up too.

[spasticteapot]

I remember someone comparing these favorably to a lot of commercial designs at $300 or more a pair. Considering that these use Peerless' cheapest woofers and what is, to be honest, a less-than-awe-insipring (albeit affordable) tweeter, you must have done one heck of a crossover.

[LouC]

You never get something for nothing. Like I said in the write up, not going to win any bass competition, but what's there is exceptionally good for the price.

[rogoll]

They look pretty sweet. I had a real internal struggle over buying the Peerless woofers, especially at the price! But ultimately my desire to stick to "still-being-produced" kept me from purchasing them. Anyway, I already have several buyouts that I need to work with before I purchase more.

Only issue, why cover up beautiful birch?

[fastbike1]

The birch used on handi-panels is often pretty plain. Sometimes we want more character and grain on our cabs.


They look pretty sweet. I had a real internal struggle over buying the Peerless woofers, especially at the price! But ultimately my desire to stick to "still-being-produced" kept me from purchasing them. Anyway, I already have several buyouts that I need to work with before I purchase more.

Only issue, why cover up beautiful birch?

[LouC]

Around here, 1/2" baltic is about the same as a sheet of 3/4 MDF. It took me about three hours to cut & bang out those cabinets with brad nailer. About 10 minutes to finish them with a sponge roller. Aesthetics are not a big concern for my workshop wall. :) Especially when it's 110 degrees. :eek:

Now find me some kid who enjoys sanding, filling, spraying for $10/hour and we're on. :D

Rogoll: Buy an extra driver on the buyouts. At $10, you've got a backup.

[xavier]

Just heard these again, this time in their final resting place: mounted on the shop wall. They're also now mated with one of Mr. Fitzmaurice's subs. Sounds great. Every shop should be so lucky.

[LouC]

Only issue, why cover up beautiful birch?

The quality of baltic out here has gone down considerably. Lots of "footballs" on both sides. You have to sort through the piles to find a clean side.

[Brewski]

Just heard these again, this time in their final resting place: mounted on the shop wall. They're also now mated with one of Mr. Fitzmaurice's subs. Sounds great. Every shop should be so lucky.

hehe Yeah I've got 4 of the woofers stashed away for another lambics build although the LECBOS would be very tempting for my garage.... (ponders how wife would take having the next project start up so soon...)

Take it easy
Jay

[rogoll]

LouC:

I saw the baffle dimensions on your site, but was wondering if you would mind providing the internal dimensions of your cabinets. Question, would the internal dimensions you used work correctly with the tube port you mention on your site?

Thank you,
Leonard

[fastbike1]

Lou gives the net volume and the external dimensions. Says the tube port is equivalent. What else do you need? If you have trouble visualizing the box, search for Boxycad2. Works well for prism boxes. Lou was careful to specify net volume, so don't forget to account for braces and drivers. Boxycad can reasonable account for bracing.


LouC:

I saw the baffle dimensions on your site, but was wondering if you would mind providing the internal dimensions of your cabinets. Question, would the internal dimensions you used work correctly with the tube port you mention on your site?

Thank you,
Leonard

[LouC]

Since everything is +/-10%, you can probably build from 18.5-22 liters without appreciable difference in bass reproduction and minor changes in port length.
I suggested 4.5" Length for 18.5 liters, 3.25" for 22 liters (the PE Cabinets). Volume of drivers & crossover is negligible. My tuning is designed to sacrifice a few hertz on the bottom end for a bit better excursion control.

[ssgt James]

Hey Lou,

This looks like a great design to get my feet wet. I had asked in an earlier post about a "budget" design, and this sure seems to fit the bill. (I was directed to your site about the Cyclops and asked about your center as well.)

If you would please excuse my ignorance, what would be involved in decreasing the width to 8". Would the port need to change? You say +/-10% on dimensions, so i am guessing, with my old ears, nothing.

I don't know how to post the original link to my post, but I am limited to 8" max for my center.

Also, this would be set to small on my receiver. Is there any benefit to making them sealed? or would that require a whole remake of the design.

I thank you in advance.
CJ

[LouC]

You might have a problem fitting those drivers on an 8" wide baffle. Maybe with 1/2" stock you can do it. You need to have about 5.75 - 6" for the driver cutout. The center to center distance on the drivers is the main thing to keep the same. You can adjust the box height & depth to maintain the same volume. There's not enough BSC to worry about the width. Unless they are going flat against the wall, or inside a tight cabinet, you can use a tube port or slot port out the back (or top, or side or bottom...) If you run them as "small" you could try plugging the port with some foam or fabric if you have sub matchup issues. Some receivers allow you to pick the rolloff, others are fixed at 80 or 90 Hz.

A good sealed volume would be about 11 liters -- not that much smaller than the 18.5 I used. F3 about 105 db. You can do them sealed, but I don't recommend it. They will be more versatile ported.

Feel free to email me if you need more help.

[ssgt James]

10-4, Thanks Lou.

[Brewski]

You might have a problem fitting those drivers on an 8" wide baffle. Maybe with 1/2" stock you can do it. You need to have about 5.75 - 6" for the driver cutout. The center to center distance on the drivers is the main thing to keep the same.

Lou,

How much would it affect your CTC if the drivers were rotated so the flats oriented with the sides rather than the tweeter? If the drivers are oriented flat to the side an 8" baffle with 3/4" MDF shouldn't be too bad, but it will limit the size of your round over. If there isn't enough room to rotate the driver 2 of the screws mounting the driver would have been driven into the 3/4" MDF I was using so they'd probably be fairly close to the seems for 1/2" widths as well.

Take it easy
Jay

[LouC]

Rotating the drivers won't do anything for the inside dimensions. The through hole is at least 5.75 (I usually cut a 1/16 over on surface mounts and/or stamped frames) I suppose you could cheat a bit on that if you had to.
I did mine in 1/2" BB and they are rock solid. I just didn't want to send a newbie down the "dammit, why didn't I think of that..." road.

[LouC]

Hey Lou,
I don't know how to post the original link to my post, but I am limited to 8" max for my center.
CJ

Let me know if you are interested in my Seas Coax center (http://www.lonesaguaro.com/speakers/coax/Coax.htm). 7.5" high, 8" deep.

It's sitting on shelf now gathering dust, it should fit your cabinet. I'm happy running phantom mode. I'd rather see it used. Email me if you're interested.Hey Yankee G.I. for you special deal...:D

[Brewski]

Rotating the drivers won't do anything for the inside dimensions. The through hole is at least 5.75 (I usually cut a 1/16 over on surface mounts and/or stamped frames) I suppose you could cheat a bit on that if you had to.
I did mine in 1/2" BB and they are rock solid. I just didn't want to send a newbie down the "dammit, why didn't I think of that..." road.

Ahh I see your point I was thinking you were warning about the two screws ~6.75" apart possibly hitting the side walls of an 8" baffle as well. I discovered that the hard way and ended up rotating the drivers as a result. (Doh daughter just used a plate as a discuss time to run) :eek:

Take it easy
Jay

[LouC]

I've finished up the LECBOS build (includes a BOM). Added some text and new pictures to my webpage: LECBOS (http://www.lonesaguaro.com/speakers/GarageMTM/Lecbos.html)

July 5 - I bumped the padding resistor for on wall mounting. Added some pictures of the final setup, and a bit more to the write-up.


Apparently the tweeter I used in this design is NLA. I've had several queries about substitutes. My SWAG would be the shielded version of the same tweeter (279-177 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=279-177)) Response curves look very similar, sensitivity/impedance is pretty close too. Try at your own risk.

Since I only measure in the box, I have no simple way to suggest or model a substitute. FWIW, the FRD/ZMA files I used are part of the writeup. Feel free to use those and work up an alternative.

[johnnyrichards]

Apparently the tweeter I used in this design is NLA. I've had several queries about substitutes. My SWAG would be the shielded version of the same tweeter (279-177 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=279-177)) Response curves look very similar, sensitivity/impedance is pretty close too. Try at your own risk.

Since I only measure in the box, I have no simple way to suggest or model a substitute. FWIW, the FRD/ZMA files I used are part of the writeup. Feel free to use those and work up an alternative.

Lou, the Vifa BC25SG15-04 is also very close to a drop in. I have both versions here, if I am doing nothing later today I will throw the 15 version in my current project and see how it looks compared to the 19.

[johnnyrichards]

I measured the BC25TG19-04 and the BC25SG15-04 (which is a regular stock item at PE for ~$13) in my Iowa project. I left the highpass filter in place so if anything, it shoudl be indicative of suitability as a drop in. Draw your own conclusions, but it looks to me to be very close to a drop in, with maybe slightly less padding on the tweeter, but that could just be unit-to-unit consistency.

Pay no attention to the legend at the bottom of the image, the hot one is the buyout version.

http://i.imgur.com/cSjBI.png

[LouC]

I've had some PM's asking about this. It sure looks pretty close. I went ahead and added some verbiage to the LECBOS page about this as a replacement tweeter. (With proper credit/blame for Johnny of course!;))

If anyone tries this, let me know and I'll add your tweaks to the build page.

[johnnyrichards]

Glad to help, Lou :)