What’s On the Bench Tonight (OBT)

[Vunce]

Lots of elbow grease put into these beauties, super job X!!

Time for a Guinness!

 

[xrk971]

Thanks, Vunce. I like how nice it makes a speaker look, but I have to admit I am not a fan of woodworking or woodfinishing. I’ll leave to a pro next time. A lot of time, elbow grease, achy muscles, stained fingers, dirty rags and drops cloths, and an aromatically pungent garage for days.

 

[bonjonno]

Just some of the reasons I'm so grateful you brought us foamcore cabinets!

 

[twocents]

A lot of time, elbow grease, achy muscles, stained fingers, dirty rags and drops cloths, and an aromatically pungent garage for days.

There are shortcuts with new technologies - a single coat product:
https://rubiomonocoat.com/en

My brother-in-law had a joinery factory the last 30 odd years and thinks this mono coat product is the best thing since sliced bread.

 

[xrk971]

On the bench is the slot loaded open baffle. Installing woofers today. Checked polarity with a 9v battery. Wired for nominal 4ohms and they all push air out of slot with +ve polarity.

Size comparison with TLs:

 

[xrk971]

On the bench tonight is the crossover for the SLOB.

Oh man, this is a very special speaker. One of the best I have heard ever. So clear and a joy to listen to. Articulate and powerful OB bass with 91dB sensitivity! Incredible.

Recording of speaker playing on mono using my phone.

 

[pinnocchio]

Looks amazing! Great work X!!

Do

 

[xrk971]

Thanks, Do! I am very pleasantly surprised by how excellent this turned out.

 

[Dibya]

That Resolution though Insane
Decay is brutally quick xD

 

[xrk971]

I revised some resistors on the SLOB dipole speaker crossover. Have a listen.

 

[Dibya]

Hi X , Did you consider using a Planer Mid?

 

[xrk971]

Yes, I have the 8in planar but it doesn’t go low enough to cross at 475hz.

Maybe a Magnepan LRS might be interesting as a top, or a DML panel even.

 

[1hiep0]

I revised some resistors on the SLOB dipole speaker crossover. Have a listen.

View attachment 1039954
View attachment 1039955

The drum sound excellent is it S Harsch transient perfect type x-over? Did you do the phase measurement by any chance? Excellent work no doubt.

 

[bonjonno]

for my taste the highs are a bit off on the drums (1st few acoustic samples)- a little tizzy. Brighter than reality. I'm a 6 decade drummer (wore earplugs always the last 30 years). The dynamics are killer. Sometimes the low mids struck me as bloated, but that may be the recording. Much of the sample recordings were full of effects and production garbage. I love the acoustic bass sound. Not surprised the overall sound is HUGE!

 

[xrk971]

The drum sound excellent is it S Harsch transient perfect type x-over? Did you do the phase measurement by any chance? Excellent work no doubt.

The phase is flat from 500Hz on up but varies linearly below woofer crossover. It is quasi transient perfect above 500Hz between the mid and tweeter but not the bass and mids. The only way to get the bass tune aligned would be to use DSP and active amplification.
Here is measured phase:

 

[xrk971]

for my taste the highs are a bit off on the drums (1st few acoustic samples)- a little tizzy. Brighter than reality. I'm a 6 decade drummer (wore earplugs always the last 30 years). The dynamics are killer. Sometimes the low mids struck me as bloated, but that may be the recording. Much of the sample recordings were full of effects and production garbage. I love the acoustic bass sound. Not surprised the overall sound is HUGE!

The highs may be a bit “hot” since camera and mic are located above measurement axis (mid woofer). There is abundant detail and maybe 4.7R padding might be better. I’ll give that a try. The dynamics of the slot loaded open baffle woofers is very nice. The bloated mid bass might be the recording.

Thanks for the feedback.

 

[xrk971]

On the bench are scrounged up parts to make a second temporary crossover board for the second SLOB dipole speaker channel.

With some Wago connectors:

We now have a stereo pair:

 

[xrk971]

Now playing stereo. About 1.5Vrms for this recording. Latest tweak to XO (lowered the woofer inductor value and reduced padding on mid) yields 91.5dB SLOB. The bass punch is insane. Don’t need more than 2Vrms for some crazy loud levels.

 

[Dibya]

Perfect speaker for all Class A setup ,
Now Mid presence is better did you make changes to Xover?

 

[xrk971]

Yes, increased mid bass sensitivity by reducing value of inductor on woofer and padding on the mid - from 3.3ohm to 0.51ohm. Overall mid presentation is more clear now. Overall sensitivity has increased a few dB. Here is predicted XO response: