• Welcome to The Audio Annex! If you have any trouble logging in or signing up, please contact 'admin - at - theaudioannex.com'. Enjoy!
  • HTTPS (secure web browser connection) has been enabled - just add "https://" to the start of the URL in your address bar, e.g. "https://theaudioannex.com/forum/"
  • Congratulations! If you're seeing this notice, it means you're connected to the new server. Go ahead and post as usual, enjoy!
  • I've just upgraded the forum software to Xenforo 2.0. Please let me know if you have any problems with it. I'm still working on installing styles... coming soon.

What happens when Flint makes a Line Array?

Flint said:
Once the wiring was complete, I placed the cabinets on the floor facing up and started filling with acoustic stuffing.

I used a few yoga mats to protect the floor and cabinets:
View attachment 8092


Then I opened the bags of cotton based down-replacement stuffing intended for pillows and quilts - a total of 10lbs, or 2.5lbs per enclosure, and yes, I did weight the stuffing to ensure I equally divided it between the four enclosures:
View attachment 8093


Next, to reduce the chances of the loose filling from dropping into the voicecoil and mechanical structure of the woofers, I used some bonded cotton sheet intended for quilts and blankets to hold the loose down-replacement back from the woofers:
View attachment 8094

Finally, I connected the speaker leads to the subwoofer drivers and set them into the speaker holes. I won't mount them until I can put some neoprene closed cell foam tape on the rear of the woofer frame to ensure a good seal in the enclosure:
View attachment 8095


You may have also noticed the felt feet on the cabinets. After looking them over to see which had the best top or bottom panels in terms of my painting skills, I decided which two I want on the top of the stacks.
Click to expand...
So do the ones with the felt feet go on the top, or the bottom?

If top, will you do the same with the bottoms to protect them / the floor?

If bottom, what will you use between the cabinets? I personally would recommend some of that non-slip thin rubber shop mat material, in black, cut to size, between the two. It's what I use between my stacked Koss, and I can confirm that even after being in place for years there is no relative movement AND when I recently separated a stack there was no deterioration of the rubber / sticking to the wood / harm to the cabinets.

Jeff
 
I was eager to be done last night, so I slapped together a simple box-frame to mount the amplifiers in which I would then mount onto the rears of the bottom two cabinets.

Here's the simple box - note that I make the "top" and "bottom" sides thinner than the left and right sides in order to allow for some airflow through the inside of the box to cool the amp. There are some transistors mounted to the main rear plate, so I assume they are the hottest running of the lot, but I thought a little airflow couldn't hurt:
LineArray37.jpg

As with all of my MDF work, the edges are simple glue-only butt joints.

I painted them with three coats of good spray on primer then two coats of toss away sand colored enamel before finishing them with three coats of nice flat black enamel. I didn't want to waste the black spray paint on tons of coats, so I used up an old can of sand colored paint for the middle two coats. I then mounted a small angle bracket to the box, applied some neoprene foam to reduce rattling or vibrations, then mounted the amp into the box before putting them on the speakers and wiring them up.

LineArray38.jpg

LineArray39.jpg
 
Yes, tweeters will reflect on left, but not the midwoofers since they are open baffle. The bass might not be balanced, but I can adjust each channel independently to compensate.
 
I say it again, these are amazing sounding speakers. Not completely accurate, not the best at imaging, and lacking the detail and subtlety I usually seek out. However, they seem more dynamic, completely fill the room, and love to play loud. This is the speaker performance that got me into this hobby and I have been playing all the old material that blew me away back in the day. Love it.
 
Today I decided to get serious about tuning these things up for the best possible sound. First thing I did was remove the office furniture from the wall behind the speakers and moved them back so they are now a permanent fixture in the room. I then measured and adjusted and measured some more. Ultimately, I had no choice but to add to the passive crossovers on the 16 driver portion of the array to tame the bass output below 200Hz. Basically, while exciting, the 8 to 12 dB boost from 70Hz to 200Hz was overbearing. I calculated, experimented, and ultimately settled on a simple passive circuit to reduce the gain in the form of a mild high pass filter starting at about 250Hz where the peak cut at 120Hz is about 12dB. I hate adding components to passive crossovers as each one adds another detrimental aspect to the sound, but the benefits of a lass heavy tone from these speakers outweighed the phase shift, ringing, and increased decoupling from the amp. In the end, I now have a relatively flat response from 100Hz to about 7kHz. Above that the beaming of the tweeter array makes it hard to measure response, but it sounds good to me. Then I add the subwoofers and I get a clean curve within +/- 3dB (6dB window) from 40Hz to 7kHz and what sounds like a smooth treble to over 16kHz. The subs have a -10dB point of about 29Hz in this room, so the bass is solid and clean.

I am satisfied with the sound, and yes, they still suck me into turning it up louder and louder and louder all the time. They seem to be unlimited in their output and, to me, they don't get harsh or painful at stupid high SPLs.

I recommend anyone who loves classic big, clean, effortless sound to come listen.

Considering I spent a total of about $1,000 for all of the parts (drivers, wood, finish, glue, wire, crossover parts, sub amps, etc.), these are phenomenal speakers. I can't imagine the same design sounding any better if I spent more for the drivers, but I am sure it would be better.
 
Looks really nice. Next time I'm out that way I need to get over to your place. My brother lives in Leander.

I just don't get the chance to make it that way.

Sorry rambling I'm tired.
 
Deerhunter said:
Looks really nice. Next time I'm out that way I need to get over to your place. My brother lives in Leander.

I just don't get the chance to make it that way.

Sorry rambling I'm tired.
Click to expand...

Well, Leander is a short distance from my place.
 
I've been asked a few times about the crossovers. Suffice it to say I am not going to give away all the details exactly, but the basic components are shown in a block diagram below.

LineArray42.jpg

These are fairly simple circuits using crossover capacitors, quality inductors, and audio grade power resistors. I am not a fan of so many passive components being inserted between the amp and the transducers, but I am not prepared to use active crossovers and more amps to make these cheap drivers sound better.
 
You must log in or register to reply here.
Back
Top