My DIY center channel speaker, very very cool looking

Alright, I'm an industrial design student. Originally I designed a box and calculated everything to the nth degree and got chastized for it being so boring... so i threw out my idea, and went back to the drawing board. I then just held onto these few concepts:

1. Very rigid mounting surfaces for the speakers
2. Curved surfaces= good, because less resonance due to reflective waves.

So, here's what happened:

Alright, so we had to design a dispenser, and I chose to do a 'sound dispenser'. It was also a plastics project, so I had to use primarily plastic in it's construction, which kinda stinks, because I wanted to do the cabinet out of wood, due to it's better acoustic properties. That said, my project was originally a box with a funky front end, which got slaughtered during critique, so I went back to the drawing board and did a TON of thumbnails. Eventually I found a design that I really liked, and decided to wall mount the speaker above the display (after xmas I'm getting a 24" iMac to use as a main machine and the entertaniment hub. Out with TVs, in with big ass computers! ).

The front face plates are really thick acrylic, and the back pods are all vacuum formed. The silver pieces are also acrylic, bonded together using plastic epoxy. The two pods are held together by a center section with massive bolts, which are also the terminals (I drilled them out to accept wire, and used washers). So basically, the bolts that hold it together are doing double duty; strength and they're conducting the power to the crossover. The speakers were hi-vi 3" extended range drivers purchased for $8.95 each, and the tweeter was a rear mount style purchased for $4.60, and the crossover was made for 2 8ohm woofers and a 4 ohm tweeter (perfect) which only cost 59 centers, all from parts express. I spent more on the paint (carbon metallic) and bolts than I did on the actual audio parts, but that's okay.

A crap speaker mounted well will sound better than a good speaker mounted poorly. Anyway, enough babble. Here are the pics:







The acrylic was lined with rubber adhered with super 77, and I also used padding for a pillow instead of expensive audio padding. The best part? It sounds freaking fantastic!!! I replaced my regular HTIB center channel and the difference is striking! Shell casings, dialogue, and anything that isn't a super low frequency has just so much more clarity, it's just freaking awesome.

Aggressively good or bad comments welcome! Rip it apart if you like, but I'm pretty stoked about it.

Interesting. You should hang it from the ceiling like they used to hang Bose 901's!

Q8Repair said:

I replaced my regular HTIB center channel and the difference is striking! Shell casings, dialogue, and anything that isn't a super low frequency has just so much more clarity, it's just freaking awesome.

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Ya? Why is the young lady in the middle picture knitting some earmuffs? Looks like something a guy would have a tough time connecting to anything in any household run by any woman I have ever known.

Chris

She's making a scarf for a relative for Xmas. She's pretty rad, as she is excited about getting my quad system integrated into a music/home theater setup, so she lets me spend cash on it. Heh.

Vice nice speaker. You could probably sell these, especially if you offered them in fashion colors - you know, for people whose WAF is much lower. My wife not only let me have big square black speakers, she bought them for me as a graduation gift. But, we aren't all so lucky. As more and more people want surround systems there is going to be more attention paid to design. Here everything gets put around the speakers, that just won't fly in many households.

Now, I'd like a nice musical subwoofer that goes down to the low 20'sHz range that I can build from partsexpress parts for a couple hundred dollars. Oh, and I'd like it to be unobtrusive That should get you a good grade!:banana:

"I spent more on the paint (carbon metallic) and bolts than I did on the actual audio parts, but that's okay.

A crap speaker mounted well will sound better than a good speaker mounted poorly." I have to admit that it is a great looking device and it probably sounds better than what it replaced. I do wonder about the acoustical design with such excessive horizontal spacing of the drivers. More of an esthetic advance than anything else, I'd guess.

Kal

Well, the horizontal spacing didn't seem (to me) to be all that excessive when I looked at the spacing of other center channels. Also, the whole thing is EXTREMELY rigid, I'm sure I could stomp on it if I wanted to...t he dome shape is extremely strong, and the front plates are very thick... so... yeah, I'm pretty happy with it. How much do you think people would pay for something 'like' this? (Like being if I did it again, I'd make it a bit bigger, probably use 4" drivers, and the front panel would probably be slightly vacuum formed also, to try to make the whole cabinet more spherical....)

Q8Repair said:

Well, the horizontal spacing didn't seem (to me) to be all that excessive when I looked at the spacing of other center channels.

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Hmmm. Well, most of them are improperly designed and, unless one knows a little about speaker design, one may be selecting those very improper features. Crossover frequency, crossover slope and driver spacing are interactive parameters.

Kal

I understand... but like I said... I spent $25 on parts. And I betch anything it sounds better than a $100 sony or bose something or other with paper drivers and no crossovers.

That said, I've read a lot about speaker design, calculating volume, differnet kinds of crossovers, how to select what order crossover you want to build, etc, but I've NEVER come across a document about driver spacing. Have any links about that subject? I'd really dig them.

Mate interesting design but how it reproduces film soundtracks is what it all boils down to with me personally.

Mismatching loudspeakers is the killer of the art of cinema sound and I doubt very much it will pack a punch in the centre and even if it does placed where it is will send vibrations down into the TV sets enclosure cursing waving lines to appear on the screen!

I have seen them all mate. Thou I think and feel with all my heart build yourself a matching set of three-screen loudspeakers bookshelf types with a good size bass mid driver and a horn for the HF and you’ll notice the difference.

Still there’s nothing wrong with a bit of experimentation.

Try playing Apollo 13 lift-off chapter 13 and I doubt it will be able to even handle the centre information down to where you can feel Jim Lovell’s hands gripping this where he looks over to the abort switch just before launch! Yeah!

If it wasn’t Christmas I would have sworn this was an April’s fools joke.

Q8Repair said:

I understand... but like I said... I spent $25 on parts. And I betch anything it sounds better than a $100 sony or bose something or other with paper drivers and no crossovers.

That said, I've read a lot about speaker design, calculating volume, differnet kinds of crossovers, how to select what order crossover you want to build, etc, but I've NEVER come across a document about driver spacing. Have any links about that subject? I'd really dig them.

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I have no links but there are several books on the subject such as Colloms' High Performance Loudspeakers. Linkwitz, too, has written about it (but not specifically as it applies to center channels) and might have some info on his website. Probably, the best specific reference might be to research D'Appolito, the developer of the MTM configuration.

Kal (not a fan of dedicated center speakers, anyway)

Dolby CP-200 said:

Mate interesting design but how it reproduces film soundtracks is what it all boils down to with me personally.

Mismatching loudspeakers is the killer of the art of cinema sound and I doubt very much it will pack a punch in the centre and even if it does placed where it is will send vibrations down into the TV sets enclosure cursing waving lines to appear on the screen!

I have seen them all mate. Thou I think and feel with all my heart build yourself a matching set of three-screen loudspeakers bookshelf types with a good size bass mid driver and a horn for the HF and you’ll notice the difference.

Still there’s nothing wrong with a bit of experimentation.

Try playing Apollo 13 lift-off chapter 13 and I doubt it will be able to even handle the centre information down to where you can feel Jim Lovell’s hands gripping this where he looks over to the abort switch just before launch! Yeah!

If it wasn’t Christmas I would have sworn this was an April’s fools joke.

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Did you not read the description and only look at the pictures? It will be wall mounted. I'm getting a new iMac in 2 weeks, which will be the main TV/computer of the house. That said it is pretty loud, and because it's ported, the bass isn't really too bad. It's not anything like the rest of my full-sized system, but then again, one can't really suspend a huge gigantic speaker on the wall anyway, plus I don't know where I'd find another matching 1960s panasonic SB-550 speaker.

PS: Center channels, to me, are all about reproducing dialogue and high frequencies. Most of the really loud low stuff gets redirected to the subwoofer anyways, especially with my technisc dts/dd decoder...

Oh yeah, I surly looked at the pictures nice workmanship but I have experienced like many before me the common mismatching of the (three-screen) front loudspeakers where the results don’t meet the expectations.

Simple, do what the professional cinemas do! If you can’t get hold of the same loudspeakers than just start all over again afresh, and it’s not impossible you’re being eluded by what is in front of you within the room!

Use the same matching loudspeakers placed across the front!

Suspending no you don’t do that wrong! Now if you have one part in the room and I’m betting on it! Place a brand new array of matching loudspeakers across the front.

But! Firstly build yourself a horizontal platform placed 1” above the TV monitor and extending the entire width of the front.

Next place the matching three-screen on top it towards the edge! and via tilting them downwards slightly and by keep the left and right not, too close to the sidewalls, you’ll start to notice the difference.

Next step build a home made THX baffle wall for the front (three-screen) it’s not impossible in fact I’m planning on doing the same thing soon enough. Mate you’ll notice an increase in performance and it doesn’t cost the earth ether.:banana:

Uh... what?

Looks nice! As long as it works for you! Enjoy your hobby! Don't mind the snobs! Is this the SH forum?

Thanks. Some people just like to shit on others to feel better about themselves.

When do you go into production? I want, I want!

Dolby CP-200 said:

Simple, do what the professional cinemas do! If you can’t get hold of the same loudspeakers than just start all over again afresh, and it’s not impossible you’re being eluded by what is in front of you within the room!

.:banana:

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Hey, Q8Repair,

Ignore drunky Dolby dipshit. I dig your speakers too! But did I miss something? Theres a cut line in the upper rear frame of this speaker. Is this part of your "spacing" issue?

I would encourage and applaud Q8Repair's work on his speakers. It might be the start of a new business for you if you're really into it. Speakers are one of the most important parts of any system. Some of the best speaker systems I've heard over many years we're handmade.

One must work with what one has. I use a vintage Quad setup in my living room and was not able to hear the center speaker information until it dawned on me to just plug the center out from my DVD/SACD player directly into the TV.

Hey thats Great I am impressed. But I would like to know how you drilled those bolts out was it by hand or a Drill press??