Cranberry Lambics

[Brewski]

I'm working on a pair of 32 liter MTM's using the Peerless 835004 SDS 6-1/2 buyout woofer and Vifa DX25TG09-04 1" tweeter. I want to thank Paul K for his advice on how to get the tuning for the towers to 51Hz, Wolf for his tips on using and preparing files to be used with PCD, and Pete Schumacher for his advice on the crossover component placement. I 'm somewhat limited to a couple of hours here and there on weekeds for the project but I'm estimating I'm at about 50% done. Here are some photo's I've taken along the way.

Figured I was going to try to emulate the paint job on the sophmores a bit and being a beer fan figured carnberry lambic was a fitting name.

I'll grab more pics and start posting updates as further progress is made.

Take it easy
Jay

[arlis_1957@yahoo.com]

nice so far brewski. the crossovers look fine.

[Brewski]

Thanks Arlis. Speaking of crossovers that reminds me I also want to thank the guys driving the measurements on a peerless thread. http://techtalk.parts-express.com/showthread.php?t=214008&page=2 Particularly NEO Dan, Drik, and Fish-24_7. With out the initial ground work I'd have not tried this. If my brother had a subwoofer I'd be tempted to have gone with the build they're working on but I'm hoping to get a little more bass out of this setup.

Take it easy
Jay

[Brewski]

Made some more progress since the last posting both "sub-baffles" are cut out one has been glued down the other will be glued tomorrow night. I used a 3" hole saw to cut out a port for the terminal cup to mount to. I'm going to need to added hurricane nut or T nuts to the sub baffle for the baffle to bolt into.

I also made blocks to mount the 2" diameter 1.5"L ports into. The ports are placed 2.5" from the bottom of the cabinet 1.5" from center on each side.

The internal braces were glued in place at 19.5" from the top of the cabinet measured internally. Pollyfill and egg crate foam will eventually be added to the top enclosure.

Take it easy
Jay

[Brewski]

I got the Lambics fired up for the first time today and was very happy with them. They are at a good starting point for tweaks. Some voices were slightly nasally so I'm going to try adding Wolf's recommended LCR of (0.75mH, 80uF, 4.7 ohm) to tame the tweeter's resonance...

Bass was pretty good but there were a couple of notes that sounded a little flat... I think I may have over stuffed them so I'm going to pull some poly out to see what happens.

Also I'm going to need to debate taking a little bit more off the tweeter padding the speaker for another -1 to -2 db's. I'm also going to play with room placement before adjusting them. I'm expecting my brother to use them close to the walls so could have had them too far out for the 50% BSC I'd modeled.

In summary I'm very pleasently surprised how good they sound considering the ~$100 spent in total for the drivers. I'm going to tweak them a little more but feel good about them so far.

I'll work on getting them painted and the final tweaks next weekend and I'll post the final crossover and additional pictures once they are painted.

Still to do list:
Round overs for the baffles
Tweak tweeter crossover
Apply bondo/spackle to sealed MDF ends and seems
Paint

Take it easy
Jay

[Brewski]

I had a request for a BoM for the build so this is the final parts for the drivers and crossover cost wise for the electronics was ~$251.22.

Drivers
2 Vifa DX25TG09-04 1" Fabric Dome Tweeters $53.64
4 Peerless 835004 SDS 6-1/2" Woofer 4 Ohm $40.00

Crossover components
Reistors
2 Dayton DNR-0.51 0.51 Ohm 10W Precision Audio Grade Resistor $2.50
2 Dayton DNR-1.5 1 Ohm 10W Precision Audio Grade Resistor $2.50
2 Dayton DNR-25 25 Ohm 10W Precision Audio Grade Resistors $2.50
2 Dayton DNR-12.5 12.5 Ohm 10W Precision Audio Grade Resistors $2.50
2 Dayton DNR-6.5 6.5 Ohm 10W Precision Audio Grade Resistors $2.50
*2 Eagle 14 ohms 14 Ohm resistors $2.40

Caps
2 Dayton DMPC-3.3 3.3uF 250V Polypropylene Capacitor $3.38
6 Dayton DMPC-4.7 4.7uF 250V Polypropylene Capacitor $14.46
2 Dayton DMPC-10 10uF 250V Polypropylene Capacitor $16.48
2 Dayton DMPC-15 15uF 250V Polypropylene Capacitor $10.98
2 Dayton DMPC-50 50uF 250V Polypropylene Capacitor $22.76
2 Dayton DMPC-6.2 6.2uF 250V Polypropylene Capacitor $5.36
2 80uF 100V Non-Polarized Capacitor $3.84


Inductors
* 2 20 guage air core .25 inductors $7.60
2 Erse Super Q 3.3mH 16 AWG 500W Inductor $39.34
2 Jantzen 0.20mH 20 AWG Air Core Inductor $6.96
2 Jantzen 0.75mH 18 AWG Air Core Inductor $14.02


* denotes non Parts express part

[gvimhoof]

Good action! Looking forward to seeing your final crossover! I've got a couple of other projects to finish first, but I also bought four of those Peerless 835004 along with a pair of Alesis Monitor One tweeters. You've used the resources here to come up with a really good looking approach. My compliments!

[Brewski]

Thanks for the compliments Gvimhoof.

I've ordered parts to modify the tweeter's crossover so hopefully I'll get them this weekend. The first models impedance was low so I'd added a 1 ohm resistor before the crossover to bring the impedance up. The LCR was causing the impedance to dip to about 2.8 ish in the revised model. So I removed the parallel 15 ohm resistor. The tweeter's impedance now has a low point of ~3.95 ohms.

I was looking at the top end drop in the tweeter and can't find away to fight it without lowering the impedance so I'm going to live with it which so far while listening I've not really noticed it yet anyways. if you have a 4 ohm reciever you could dabble with increasing the size of the resistor in zobel but that will quickly drop impedance.

Bass should be slightly more prominate after the tweak. Currently room placement wise the speakers seem to sound their best about 6" to 8" inches away from the wall. I've still not pulled some poly out as of yet... I figured I'd wait untill I had them open for the crossovers to take care of the poly.

Take it easy
brewski

"Small update while working on the speakers found an error in the model where I'd reversed the values for the zobels resistor and cap. Deletedprior jpegs. I wired up the LCR in the order of literally LCR last night. While making a schematic today saw they should actually be CRL so I'll need to fix that friday night before I can post listening impressions.

Updated impedance information low is a short trip 400hz wide to 3.5 In general I'd call it 4 ohms since the dip is short. Included FRD and ZMA files along with current models jpegs."

[Brewski]

Small update for those interested in the build. I've installed the LCR in crossover and the tweeters sound much better. I also removed about a hand full of poly from both speakers and I think that's helped with making the bass not feel so flat...

I'm going to start paint prep later tonight and hopefully start painting them tomorrow. I'll update the BoM tonight with the current parts list and possibly post a schematic later tonight.

Take it easy
Jay

[Wolf]

I'm not really certain what the 14 ohm resistor is for on the woofer, as it probably is wasting some sensitivity, as well as being unnecessary.
Just my 2c,
Wolf

[Brewski]

I'll try taking the resistor off tonight or tomorrow. I've started painting them so I have them apart anyways currently. Originally I was trying to tame the "knee" that went slightly above 90 when a 10uF cap was there. I was a bit affraid of hearing the 3 db shift between 800hz and 1500hz. When I added the LCR and resistors to the tweeter's side I changed the cap to 15uF but didn't take the resistor out.

Thanks
Jay

Looking at the PCD layout file I have R3 in parallel with C2 on the crossover board when they should be in series.

[Wolf]

Looking at the PCD layout file I have R3 in parallel with C2 on the crossover board when they should be in series.

If it's a quasi-zobel, then it's fine.
Later,
Wolf

[Brewski]

I took work off on Thursday to get about 10 hours of work in on the speakers. I'll post some more pictures up as I get them. I've got to let them dry a bit before trying to get them back together.

I'm not sure if these are the final colors for the speaker but I'm hoping too see what they look like inside on Sat once they are re-assembled. I may hit the regal red with the duplicolor metalic red, or glitter effex clear, or metal cast smoke.

Currently under dirrect sunlight they're too red for my taste. Looking at the baffles in the garage though the color looks much more mellow when inside.

Take it easy
Jay

[Brewski]

Ok going to touch up the speakers a bit paint wise but they're done for the most part. I've seen the red in the house and really liked the color indoors. The copper in the baffles needs to be sanded down and re-shot I kept getting the occasional "blob" in the middle of trying to get them painted on Thursday. My brother was home this weekend from school so I crammed to get them back together from Thursday's painting session so he could hear them.

At 2am in the morning I was chasing a problem causing the receiver to enter protection mode. One of the tweeter crimps was lose which apperently was the root cause of my problem. After fixing that they played for three hours this afternoon without any problems. (forgot until breaking them down for some paint touchups to snag pictures)

For a breif trip into fairly loud levels, at my brother's request, we played Mad Season, Alice in
Chains, and Stir It Up (Marley) at -30db on my HK 635 which was bordering uncomfortabely loud in my living room to see how the bass sounded at high volumes.

Over all it's been a fun first project!

Thanks to those that helped steer me in the right direction.
Take it easy
Jay

[Wolf]

You're welcome, enjoy them!!
Wolf

[jeff_free69]

Is that the optimal arrangement for the inductors??

I thought one should be set like its rolling the other.

(And it would be bad to look thru the hole and see the other)

[Brewski]

I'm assuming you're looking at the highpass. I've not noticed anything particularly disturbing in the tweeter with that config. I knew I needed them to have a 90 degree offset which is why the LCR inductor is standing.

One thing to note, after talking with Wolf, I found out that the order of the LCR doesn't matter since it's in series. I'd argued with myself that it shouldn't matter but figured I'd reposition the parts anyways in case there was a problem with my logic. :rolleyes: So getting back to the point, the standing inductor could be placed further away from the inductor laying flat if someone else was building a set lambics for themselves.

On the low pass I'd posted that config up for feedback and was advised to rotate the iron core inductor to it's current positioning so I think it's ok as is.

And since it was asked somewhere else the aligator clips were there only for testing :D

Take it easy
Jay

[jeff_free69]

I'm assuming you're looking at the highpass. I've not noticed anything particularly disturbing in the tweeter with that config. I knew I needed them to have a 90 degree offset which is why the LCR inductor is standing.

Jay

yeah that's the one that stood out. Just pointing it out becauase I just assembled an XO (for the Lineup R44), and found references on this board that the "rollover" alignment was best. Its just an easy rule of thumb , but I did not test (and don't remember enough college physics/electronics to confirm).

[rogoll]

Would you mind providing the internal dimensions of your cabinets, or point me to them if you have already done so?
Thanks,
Leonard

[Brewski]

Would you mind providing the internal dimensions of your cabinets, or point me to them if you have already done so?
Thanks,
Leonard

The cabs were made from 5 (40" x 8") cuts of 3/4" MDF. So the internal dimensions ended up (6.5w" x 8d" x 38.5t"). External dimensions are 8w" X 10.25D" x 40" Due to the removable baffle portion I'm gaining slightly more area from the cutouts.

I've also been simming using the SB25 tweeter's in PCD as a possible change if I build another version of these for myself to lower cost and get to fewer crossover parts. The originals have been dropped off and now reside with my brother in VT.

Take it easy
Jay

I've had a few PM's about the lambics so I've added pictures for simmed revisions for SB25 or DX25 tweeter if/when I build another set of Lambics. These crossovers are only simulated at this point. If someone else tries them let me know what you find.

[critofur]

Hey, how do you like the sound w/the DX25? That tweeter was on sale at a great price DOTD - I'm sure lots of folks picked them up, and are those the $10 6 1/2" Peerless woofers?

[Brewski]

Hey, how do you like the sound w/the DX25? That tweeter was on sale at a great price DOTD - I'm sure lots of folks picked them up, and are those the $10 6 1/2" Peerless woofers?

I liked them a lot and was comparing them head to head with the SB29RDCN tweeter which was/is in the speaker project for myself (http://techtalk.parts-express.com/album.php?albumid=311). In general I liked the top end on my brother's speakers better and the low end of the FW168's better than the Peerless. Cost wise though the Lambics were ~$250.00 and the Ruinations were ~$400.00 and I didn't really hear enough of a difference to justify the extra money spent on my speakers. (Note I really enjoyed listening to both speakers I just think the Lambics give you more for your money)

I think between the two tweeters the DX25 was more detailed and accurate on the top end. I think this could be noticed mainly when listening to older recordings where IMHO the SB29 masked some of the imperfections in recordings where as the DX25 played what it was given.

As for the woofers yes they are the $10.00 peerless buyouts so for a little bit you could build this project for $72.00 spent on drivers. I went ahead and bought four more of the tweeters when they were on sale and already have 4 of the peerless woofers on hand so I might build another set of lambics next spring. With the original pricing on the peerless woofer being $43.00 each I couldn't enter them as a less than $200.00 speaker at next years Dayton gathering, so that took a little wind out of my sails for building the next pair.

Take it easy
Jay