New office system!

grey

Super Member
I found these cabaret cabinets for sale that were not so local. The upper drivers were already wasted or missing. The guy was very cool and said he would hang onto them for me. I hate working with wood and I've been looking for some e145 drivers, so it was a perfect situation.

I've had all of the other parts on the shelf for many years. The horns are a Yuichi a290 design and the drivers are 2445 with 2452-sl diaphragms. The entire horn assembly feels like 80lbs:eek:

This was all cobbled together last night while repairing stuff along the way. Tonight, the sl phragms/foam pads were installled and more work was done in the driverack. Turns out that they like a lower order Butterworth filter. For no measurements or eq, the system is quite listenable as is. You would need put your head in the horn to pick up any noise.

I tried to work in some 2405 drivers, but I've not found a decent amplifier yet. I'm looking for something with low dc output, low noise, and a protection relay. There are two 6215 amps that are dead on the bench with several hours into repairs. There is another D45 that has no relay and puts out dc on shutdown.

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New audio rack!

It already has some cooling fans installed. Although the rack will be somewhat isolated, I may need to fit some modern, quiet fans in there at some point. The UPS at the bottom may work, but needs new batteries for sure. The black strips at the top near the fans are programmable power relays.

This is the plan:
Repair or purchase new ups.
Purchase an open source module like a raspberry pi. This will become the rack management brain.
Purchase a few high amperage contactors for the power amplifiers.
Build or purchase a couple of ambient temperature sensing circuits.

Programming goals:
On/off power sequencing.
Power sensing and shutdown for brownouts and power loss.
Temperature sensing for fan on/off switching. Will possibly add hi/lo air volume switching as well.
Power off sequence in the event of an uncontrollable temperature range.

Btw, that is my old office system sitting on top:no::D

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Not at all what I was expecting when I read "New office system". :D

Super cool. I've been wanting to build something like this for a while now.
 
Posting up some progress with the system. Another UREI 6215 amplifier is here for the 2405 ring radiators. It's doing all the right things and it's not cooked to death. It's currently on the bench for a full restore to last many maintenance free years. A couple of the 6260's have been through the bench and performing very well. The 6290 on the dolly is in need of help.


Not at all what I was expecting when I read "New office system". :D

Super cool. I've been wanting to build something like this for a while now.

Thanks! Hearing the high sensitivity drivers with music that I've picked out is a completely different experience for me. I've settled on an 800Hz 12dB butterworth filter as the most natural sound. The cabaret bass cabinet is, in a few ways, completely terrible without the 80Hz crossover point. The 4645 cabinets makes everything just right. Still very much worth doing until a very low freq. solution is there.

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That stuff wouldn't even fit in my office! Depending on the tuning of the 4645 cabinet, you should be able to add EQ to get response to about 20Hz like was done with the JBL B460 sub. Yeah, you probably already know that since it obvious that you like your JBL gear.
 
One if the monster 6290 amplifiers is repaired and now in business. I have a new Papst quiet fan on order for it.
90% of the restore/repair is complete on one of the 6215 amplifiers. It had an on/off pop a couple of times and this shouldn't be happening at all. Could be that the relay is just worn out and I need to address that sooner than later.

Being that the small amp is working, the 2405 tweeters are now playing just fine.

That stuff wouldn't even fit in my office! Depending on the tuning of the 4645 cabinet, you should be able to add EQ to get response to about 20Hz like was done with the JBL B460 sub. Yeah, you probably already know that since it obvious that you like your JBL gear.

Hi Don,

I think this particular cabinet is tuned at 30Hz? If that's the case, no boosting under 30 unfortunately. It's been a few years since I've looked into this stuff and could be wrong. I recall some single a dual models tuned a bit lower. These cabinets were acquired ~2013. Maybe some custom 10-12 cu. ft. cabinets are a possibility down the road.

I have owned a B460 and had a bit of fun with that and DSP. That was the start of the 2245 addiction.:thumbsup:

btw: I like TAD stuff too! It's just that the TAD prices don't like me very much.

Jeff

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There was some not so good things happening with my old measurement system and I had to come up with something else.

The old microphone stuff was still there and I had and old E-MU 0404 external sound card. I can't remember why I purchased the E-MU, but I'm so happy that it's here and it still works. The only thing left to do for hardware was build some cables and a 9v phantom supply for the mic.

An ARTA license was purchased and REW was downloaded. I went through some of the initial calibrations and things are looking bright!
I will be kicking in a donation to the elves at REW as well. The software appears to be phenomenal so far.

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I think this particular cabinet is tuned at 30Hz? If that's the case, no boosting under 30 unfortunately. It's been a few years since I've looked into this stuff and could be wrong.

I was thinking you could extend the ports to get the tuning down to ~24Hz like the B460. 12 ft^3 works like a champ...
 
I've made some progress on calming down the fan noise in and out of the rack.

The old array of three fans on the top of the rack are Comair Rotron labeled as a 225 cfm pack. The new AC Infinity airplate array, at a max of 150 cfm, reduced the noise considerably. I had to take the unit apart and use just the fans due to spacing. I used the old, chrome fan guards and those seem to add bit more turbulence over the airplate guards. The noise drops more when they automatically slow down in these summer evenings. I went with these as they are fit for the old 119 mm fans and there is a nice controller included. I can likely use the internal alarm signal as a trigger for the more complex rack automation in the future.
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The UREI amplifiers have vents aligned over the transformers and they were engineered to be stacked directly on top of each other. I purchased two of the infinity multifan S2 units. They are positioned on the top amplifier in the stack and pull air through these vents for internals and transformer cooling. The hot air goes to the back of the rack where it belongs. They have removable silicone standoffs and seems to be a nice, easy solution to drop right on top of your hot gear. The Infinity controller will power these and can power up to six fans if they are from a series specified in the docs. All of this Infinity equipment is doing what it should right out of the box based on initial testing.
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I went with a new Pabst fan to replace the loud unit in the 6290 amplifier. It is wired to run at full speed. I can't recommend this particular fan as the low freq. noise from an imbalance is louder than the air turbulence. It spec'd well and maybe I just have a bad one or the sleeve bearing units are just not the way to go. I'm looking at different Pabst with ball bearings and a bit more cfm. This is still much quiter than what it had. I figured that it would would be a good idea to do the fan swap on the dolly vs. lifting it to the bench. I found out that this was a bad idea when I desoldered part of my finger. I had to drill out the chassis threads and I need some longer screws to put the fan guard back on. There is room in the chassis to fit a 5v fan/transformer and this may be the best quiet solution.
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The high pitched noise from the driverack fans is easily audible, and even closed in by the rack, still annoying. This thread from the LH forums discussing Noctua 40mm fans seems like a good route.
 
I was thinking you could extend the ports to get the tuning down to ~24Hz like the B460. 12 ft^3 works like a champ...

I measured less than 3in. before running into the rear cabinet materials. Much interference if they would need to be extended.

The project box in the JBL diy subwoofer article has similar dimensions without these problems and it's tuned lower. Maybe there is an easy way to achieve this with some box modeling.
 
What grey is not telling us is that this is a Whole Office System, for him and the other 500 other employees. I sure hope that the floors above and below enjoy your choice of music!

BillWojo
 
What grey is not telling us is that this is a Whole Office System, for him and the other 500 other employees. I sure hope that the floors above and below enjoy your choice of music!

BillWojo
Hi Bill,

There is a big door from the first picture that opens up into the building. It does a fine job if it's open.:thumbsup:

Jeff
 
My gross delays and shameless laziness on this project may have paid off a bit. She is filled to the head rests with used 1, 2, & 3 in. room treatment panels.:beerchug:
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More parts have arrived for the rack automation. The contactors are Packard 30A units with a ~115v coil. They should support any amplifier power up that is reasonable for this situation. Hopefully they don't present any noise on the line. More testing to be done.....

The power supplies are oversized to handle a variety of 5v and 12v fan configurations along with misc. future expansion. My thoughts are leaning towards a 8x solid state relay pack with an Arduino to finish this off.

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A sound level meter is absolutely mandatory for a system like this. I've carried it from my home system to this system to get a feel for my SPL perception. My initial perception was off by a large margin. This system plays ~9-10 dB louder to achieve the same perceived SPL and my home system isn't a complete slouch. This is due to the very low levels of distortion. I was warned about this and the warnings are real!

Excerpt from Drew Daniels' ancient audiophile system:
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DISCLAIMER: A SERIOUS WORD OF WARNING


The system described here is easily capable of producing sound pressure levels far in excess of that which will cause irreversible hearing loss--don't take this lightly. You might suffer not only permanent hearing loss, but also constant ringing in the ears that can cause insomnia and lead to nervous disorders or emotional problems.
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Pic of everything unloaded. The stuff inside the panels looks like roxul.:dunno: It's a light green color.
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More fun and screwing around with factory cabinets. Does this look somewhat familiar?

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