Mantown

[Alex2507]

I thought I had put something in backwards too,

I guess I got a measurement anomaly and lost my mind yesterday.

Oddly enough my response curve is best just the way I've had it at least ever since the tweets got bi-amped and more than likely they were wired like that before the tweets got bi-amped. In my defense ... drugs ... but they were not wired wrong to begin with. I ran YPAO and removed their 6 db gain at 16KHz.

Looking at the schematic my tweet appears to be out of phase but any changes in polarity cause the response curve to look worse so it just stays like this and YPAO says it's all in phase so who am I to argue. And I can't remember if I did anything weird and creative back where I can't see the wires.

REW has saved me. Glory be ...

 

[Alex2507]

Here's the main view ...

It's all coming apart for, first a DIY GTG and then for a re-do on ... mostly everything. I've been spending time drawing out a lay out to plunk the speakers under the wall mounted TV. I would put the ampless RBH sub in between the speakers but the damn record player needs that spot so it's the corner for the sub.

I think Eddy may be inheriting the DIY subs. That might just be the drugs talking but he's old and alive so what the hell would anyone wait for after that? I'll just end up getting it back after he's dead. God rest his soul ... in advance. I need younger friends.

 

[Alex2507]

I'm building a little amp stand for the 3ways. Gonna go with the biamped version which sucks up 4 channels on Kurt's 7 channel amp. A little late now but if I had put some thought into it, I could have broken up the low and band passes on the xo boards to allow for tri amping. Anyway, it ought to be a nice little shrine to the god of conductivity. I'd like to get a prominent TT alter for the ritualistic slaughter of usable space. Plus TTs are cool and I'm cool. Don't you want to be cool too?

Gotta remember to take the camera.

Gonna show you what it looks like when you're not rich but you like nice sh!t.

*knock wood*

 

[Alex2507]

Gonna show you what it looks like when you're not rich but you like nice sh!t.

It looks like work, that's what it looks like.



I'm gonna stuff that hole with this:



It won't be seen by the upright but this is the mount for the TT.



and these are the grills with the magnetic conversion:



The TT will fit into this Walnut enclosure. It was prefinished so that's why it looks so nice. I can't get that level of refinement.



Don't mind the glue. It'll clean up.

 

[Swerd]

I know you have an AR turntable that should resist most acoustic feedback and other sources of mechanical vibration. I can't figure out how you plan to mount the turntable on that large piece of steel (?), but I worried when I saw it. Will the steel readily transmit vibrations that come from the speakers, through the wall studs?

Make sure you build your turntable mount to allow easy modification, in case it "amplifies" acoustic feedback, footsteps, slamming doors, etc. The mods may be as simple as adding some poly foam, sorbothane rubber foot pads, or other dampening material between the steel and the wall studs, or under the turntable.

Your design may have other good features I can't imagine, so I'll stay tuned.

 

[Alex2507]

I know you have an AR turntable that should resist most acoustic feedback and other sources of mechanical vibration. I can't figure out how you plan to mount the turntable on that large piece of steel (?),but I worried when I saw it. Will the steel readily transmit vibrations that come from the speakers, through the wall studs?

No. It's that sound proof steel.

Make sure you build your turntable mount to allow easy modification, in case it "amplifies" acoustic feedback, footsteps, slamming doors, etc. The mods may be as simple as adding some poly foam, sorbothane rubber foot pads, or other dampening material between the steel and the wall studs, or under the turntable.

I want the TT off the floor. Nobody is walking on the walls. An upside down TV stand mounts to the steel on a plastic bushing. Then the bottom of the stand (now in the upright position) has rubber feet. Then a walnut platform sits on that.

Your design may have other good features I can't imagine

, so I'll stay tuned.

I can't imagine what other good features might pop up down the line either. I got some primer and paint on the steel so it's starting to look like something. I need to frame the wall cavity to hold it. What a f^%&in' bruiser that thing is. It would take a lot of acoustic energy to ring its bell and that's just what it sounds like when you hit it with a hammer. The steel is pretty soft actually. Where I did bean it with a hammer, it left a mark and it was surprisingly easy to drill but tapping through half inch of any steel isn't a picnic.

The TT housing is in ManTown. Gotsta make a couple of holes for wires and glue up the back pieces. It's starting to come together for me visually.



That leg on the speaker stand is Maple with a Walnut Danish oil finish. It ties back into the solid
walnut of the TT platform and housing.



The white line around the bass driver bugs me too but the grills aren't far off.

 

[everettT]

Inquiring for a friend about affordable sound proof steel, pre lined of course

 

[everettT]

Curious about the upper box with the underhang. Have you experienced any lower midrange excitement?

 

[Alex2507]

Curious about the upper box with the underhang. Have you experienced any lower midrange excitement?

I was dry fitting the TT with wood sticks going from speaker to speaker. The underhang is temporary.

 

[everettT]

I was dry fitting the TT with wood sticks going from speaker to speaker. The underhang is temporary.

You may have posted that but I'm lazy as puck

 

[ryanosaur]

Gotsta make a couple of holes

+1,000 for using "gotsta" in a sentence! I think Scrabble has a bonus for that!

Lookin good!

 

[Swerd]

The white line around the bass driver bugs me too but the grills aren't far off.

Take out the woofers and use a black Sharpie pen on any bare wood that wasn't painted black. Generic brand markers also work, but Sanford Sharpie is number 1 among Pro/Am Speaker Builders.

I did the same on your MB27 cabinets. No one knows but me – and now you.

 

[Alex2507]

Take out the woofers and use a black Sharpie pen on any bare wood that wasn't painted black.

I'm hoping to never take the woofers out again. My solution is is as stated: grills.

 

[Alex2507]

TT stand, Made in America



It effin' near took a crane to get this thing up ... the stairs.




The hole got loads of wood, sound caulk, some insulation and sound proof carpeting was thrown into that mix at some point.






Assembled with sockets and wrenches ... not chop sticks.





The Money Shot w/ amp stand. Gonna have the tweets on their own amp channels again ... eventually.



It took a long time but I'm spinnin' and grinnin' once again ... 3db would definitely approve.





EDIT: I meant to say once again how much I am enjoying these speakers and subs. Thanks to a good handful of members, and ex-members actually, this is a decent rig.

 

[Swerd]

How well does that ½" thick welded steel box-tube work as a turntable stand? The AR turntable was always good at preventing acoustic feedback by itself, without any heroic installations. Does the steel mount prevent acoustic feedback or amplify it?

 

[Alex2507]

Does the steel mount prevent acoustic feedback or amplify it?

With my luck the feedback is amplified but it still beats anything that an attachment to the floor could offer. Any acoustic energy the wall sees and the steel amplifies, seems to be below my hearing threshold. Even the dresser the TT sat on before, had to be anchored back to the wall to get the front legs off the floor to prevent records from skipping as I walked by. So the steel on the wall works better than anything on the floor. I could further the decoupling by putting the TT itself up on closed cell foam that I got from work. I probably will do that after tape, paint, trim, wiring (?) etc. That will probably be next year though. Like half this year went up in smoke and I haven't cracked a mud bucket yet (it's still out in the truck).

The two studs on either side of the steel are tied together above and below the steel with tight-fitting wood framing. About 4' above that, the studs are tied together yet again by a wall mount for the TV (heavy as$ plasma). You'd have to fire a cannon in here to rattle that section of wall. The 12-1/2" header and sill 2x4 framing pieces had to be beat into place (super tight), effectively bracing the studs to each other and against the rest of the wall. Then the weight of the steel and old school plasma provide a sort of friction anchor and further wind the spring that I imagine the studs to be. This is Scientific Bosnian Mass Loading. For $19,000 I come to your home, install TT stand. For limited time, plane ticket for me and for steel included.

 

[Swerd]

With my luck the feedback is amplified but it still beats anything that an attachment to the floor could offer. Any acoustic energy the wall sees and the steel amplifies, seems to be below my hearing threshold.

It seems like your arrangement works. Once you've heard acoustic feedback through a turntable, you'd know it right away – it creates a muddy bass sound, depending on the music you're playing.

SBML Scientific Bosnian Mass Loading – I love it.

AR turntables were well known for a clever internal suspension that resists acoustic feedback better than any other turntable I've known.

Even the dresser the TT sat on before, had to be anchored back to the wall to get the front legs off the floor to prevent records from skipping as I walked by. So the steel on the wall works better than anything on the floor.

Resisting skipping due to foot steps is another question. I've had that problem too. I carefully leveled the shelving the turntable sat on, and added stick-on soft padding under the turntable. After that, only deliberately heavy footsteps caused skipping.

 

[Alex2507]

Resisting skipping due to foot steps is another question. I've had that problem too. I carefully leveled the shelving the turntable sat on, and added stick-on soft padding under the turntable. After that, only deliberately heavy footsteps caused skipping.

I haven't cranked it loud enough to get feedback. That felt strip is what I call fuzzy wuzzies. They're everywhere, under everything except the TT at this point. I've been going through some Herb Alpert and Henry Mancini this morning. I'll have to move everything off the wall to patch it up so I'll be losing the TT again. Knowing this pains me and maybe for the first time ever, my procrastination has a valid argument.

However the 1000' of speaker wire out in my truck and several unused amp channels right here in ManTown call out to me, "Come ... waste all your f^%&ing time doing sh!t that don't count ... ".

This struggle is called Lazy -vs- Stupid.

Either way, I win!

 

[Swerd]

"Come ... waste all your f^%&ing time doing sh!t that don't count ... ".

This struggle is called Lazy -vs- Stupid.

Either way, I win!

The cheap and easy solution is to ditch the feedback & foot fall sensitive analog turntables and play music digitally – CDs or the equivalent downloads.

I think it's time for my favorite turntable cartoon

 

[j_garcia]

Been a while since Mantown has been visited.