Loudspeaker Endtables

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Hi Cal,

Thanks for explaining, and thanks for the speaker suggestion.

I think the sub will go a little lower than I need, especially since I live in an apartment. You also nailed the other issue, I think this would be exceeding my funds. with the two plate amps adding $100, maybe it wouldn't. Budgets can be pretty flexible.

I don't think I want to put both the mid and the tweeter up top. I would like to keep the top surface flat, and have the tweerter in its own little box so that I can be flexible with its placement.

-m
 
baffle step is best explained here.

I don't think I want to put both the mid and the tweeter up top. I would like to keep the top surface flat, and have the tweerter in its own little box so that I can be flexible with its placement.
Acoustically you want them together, separating them is going to be your first comprimise in quality for aesthetic purposes, but its up to you.
Top surface flat... not to be a smart alleck but are you not putting a tweeter up there already?
You are starting off neglecting some important acoustic princple here in order to have neat endtables, this is ok but they will not sound anywhere near as good as the Wharfedales. At this point few here can offer you any insight as to how to go about making these sound good with a remote tweeter, I recommend building a small cheap tweeter box and woofer box and listen to the effects of wide spacing, with large time delays.

FYI, use one amp to drive two 8ohm woofers in parallel, ie. stereo music with mono bass.
Also you asked about directionality, all speakers begin to beam when the wavelength of the sound being played is shorter than the diameter/width of the driver ; c=f/d> f=c/d c-speed of sound, d-diameter of speaker f-freq. where beaming starts,ex with 8"woofer: (13500in/sec)/8"=1687hz, near this freq. and above the speaker will start to narrow its acoustic output, the higher you go the narrower it gets.
 
okay, thanks for the suggestion nunyafb. I took my old 3-ways and unplugged the mid. Then I took one of the tweeters out of its hole and plugged it. This tweeter I put a couple feet behind the woofer and did an A-B comparision with the unadulterated box (except mid unplugged).

Conclusion: you're right, it sounds very different and not in good way. Lessening the seperation improves things, but certainly the best will be no seperation. I'm not sure that I couldn't live with it, but it is sub-optimal.

So, now my question is how far down would the crossover be such that all the vocals would be in the mid/tweeter? Also, I'm think if I put one woofer on the front face and one on the side face wouldn't that help?

I didn't understand what you were saying here: "FYI, use one amp to drive two 8ohm woofers in parallel, ie. stereo music with mono bass.", but your description of reltion between the driver size and the frequency (wavelength) focus sound was incredibly enlightening. THank you.

cheers,
mark

p.s.
all I had in these old 3-ways was 2 caps and and one non-inductive resistor!
 
Welcome to the argument of time alignment, now for fun see how much misalignment it takes to be audible.

Amp: it was suggested to use that amp, however you thought you would need two amps. If instead of the woofers he referenced, you purchased two 8ohm drivers you could wire them in parallel and drive them off one amp despite the two endtables.
 
I'll have to play with that tomorrow as it's too late to crank any tunes now.

okay, now I see what you were saying about the amp and two speakers. I'll think about that.

here's yet another question. If I wanted to mount a mid on top as you showed, but I put a hole through to the a sealed portion of the lower box for the volume needed by the mid, what are contraints on how large that hole would have to be to be effective?
-m
 
On top, I actually drew a 2-way with an 8" woofer, I think however you'll be happier with a 2-way plus sub. If you do this you can use a standalone sealed enclosure for the mid and tweeter and have the flexibility you mentioned earlier.
I dont know how large a hole would have to be, my advice make it as large as you can so it doesnt behave as a port. As it gets smaller you begin to get a second tuning going on, you can read up on double chamber bass reflex designs to know more.
 
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Hi Mark,
I still like our original design - I think it's going to look way cool. Could turn out to be a nice retro mid century design. Very hip!

To answer an earlier question, the reason your table speaker made me think of an omi design is because you have the mid and woofer on 2 different sides and said that you didn't usually sit in front of the speakers to listen. So it seemed you might want an "Ocean of Sound" in the room. Or maybe not. ;)

To answer your more recent question, you should keep the woofer below 100~120 Hz if you want the voices in the mid driver.

Reading the thread again and looking at your sketch, it stuck me what I would do. Here's my harebrained idea:

Put a mid in the slanted side, just like on your sketch, then use a down firing woofer - or even up firing under the table top, if you're brave.
Point the table side with the mid toward the part of the room you want. Keep the tweeter in the movable box, or just put it beside the mid. The mid can be in a small sealed box. The woofer could be sealed or closed, just depends on what you find that you like. As you have plenty of room for the woofer, you could use an 8, 10 or 12 inch. Place a Lava Lamp and top and you're ready to go!

Use this nice Tang Band W6-789 for you mid. Mount it on the sloped side of the box, pointed into the room the way you want. The Tang Band W6-789 is a great driver at a great price. Well built and sweet sounding. I have 4 of them in my living room. It's called a woofer, but really it's a wide band mid. And the mids on this driver are really, really nice. Because of the W6-789's wide bandwidth, you can cross it down low and up high - as high as 5 KHz or more. (This one goes to 11). So choice of tweeters is easier. The Tang Band is nicely efficient, too - and that's a good thing. Using a wide range mid like this makes crossovers easier. WIth this setup, most of the music will come from the mid, with just top and bottom fill-in from the other drivers.

You can't go wrong with this mid, and your tweeter will be easy - that just leaves the choice of a sub. Plenty of projects of choose from out there. Just find a kit or project that is well documented and established. And there you go - the coolest end tables in town!

When I get home tonight I will try to simulate the W6-789 in a closed box for midrange use down to about 100Hz.
 
panomaniac said:
To answer an earlier question, the reason your table speaker made me think of an omi design is because you have the mid and woofer on 2 different sides and said that you didn't usually sit in front of the speakers to listen. So it seemed you might want an "Ocean of Sound" in the room. Or maybe not. ;)

yes, this is true. I sit at my desk across the room, so the side driver from one speaker will be roughly racing me. So, when I'm at my desk my main concern will be gettig the music into the air as opposed to the floor or bouncing off the table top, or obstructed by my fuzzy beanbag chair and mushroom stool :D .

Put a mid in the slanted side, just like on your sketch, then use a down firing woofer - or even up firing under the table top, if you're brave.
Point the table side with the mid toward the part of the room you want. Keep the tweeter in the movable box, or just put it beside the mid. The mid can be in a small sealed box. The woofer could be sealed or closed, just depends on what you find that you like. As you have plenty of room for the woofer, you could use an 8, 10 or 12 inch. Place a Lava Lamp and top and you're ready to go!

I like the thought of puttinf the tweeter with the mid on the slanting face because it's clean on top, but I guess the question is how detrimental to the sound will it be to place the tweeter so close to the floor? What I would really like to do, but it would ge complicated is to have the tweeter in a seperat box that fits into a cubby on the front so that it could be moved to the top if desired. This way I could cater the configuration to my current usage.

I was checking out this driver last night with the thought of skipping the tweeter alltogether:
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=264-844
Is it difficult to supress some of that high frequency (>5k) roughness in the XO. Are there better choices?

I was also wondering about 3-way XOs as I dozed off. Instead of a 3-way, couldn't I use 2 2-ways? The first would split off the woofer and the second would split the mid from the tweeter.

Use this nice Tang Band W6-789 for you mid. Mount it on the sloped side of the box, pointed into the room the way you want. The Tang Band W6-789 is a great driver at a great price. Well built and sweet sounding. I have 4 of them in my living room. It's called a woofer, but really it's a wide band mid. And the mids on this driver are really, really nice. Because of the W6-789's wide bandwidth, you can cross it down low and up high - as high as 5 KHz or more. (This one goes to 11). So choice of tweeters is easier. The Tang Band is nicely efficient, too - and that's a good thing. Using a wide range mid like this makes crossovers easier. WIth this setup, most of the music will come from the mid, with just top and bottom fill-in from the other drivers.

You make a compelling case for this tang band, but I would really like to get only speakers that I have a frequency response curve for, and preferably a CLIO, but that's a lot to ask. I'm a numerical modeler by trade and so I would like to rely heavilly on modeling before I buy any components.


When I get home tonight I will try to simulate the W6-789 in a closed box for midrange use down to about 100Hz. [/B]

thanks! At what frequency do we call it a "sub-woofer" as opposed to a "woofer"? I'm thinking I'd like to get down to 40Hz, how big a woofer in a sealed box should I expect?
 
BTW, it's interesting that you mention the whole retro thing. I was recently at my wife's grandmother's house and there she had a buffet table that under the lid had an LP player in the center and a speaker on each wing. Seeing this, in combination with lots of thinking about speakers, probably sparked the endtable-speaker idea.
-m
 
sorry, another comment:

panomaniac said:
then use a down firing woofer - or even up firing under the table top, if you're brave.

I could face the woofer up, but then I would loose the shelf functionality, which I really like. Facing the woofer down worries me about pumping low frequency directly toward my downstairs neighbors. So, even though I very much prefer these two options for astetics and coolness, I think out the side will be the way I go because of othe constraints.
-m
 
Mark,

being car speakers, they don't know where the person is going to mount them (doors, back shelf, box etc.) so they don't publish anything that might deter a sale.

Car speakers are expensive for what you get, but if the other ideas don't work for you then maybe that's what you should do. It would be a shame though since you are an accomplished woodworker. If this idea doesn't come to fruition you can consider making lamp speakers to sit on the table.

No I'm not joking. I've been throwing that idea around for a bit now but nothing to show yet.
 
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curiousburke said:
You make a compelling case for this tang band, but I would really like to get only speakers that I have a frequency response curve for -


Bob's your Uncle! W6-789 Frequency response.

Below in a zip file you will find the W6-789 response chart converted to an "FRD" file for use in Unibox and other programs. Also the in the zip are the FRD file for the driver in an 8 liter box and the plots in GIF format. Nice and flat from 100Hz to 6KHz, then rolls off at each end. Might not even need a high pass filter. Just a little inductor for low pass.

The little 3" Bamboo Tang Band might be nice, I have not heard it - it gets mixed reviews. I have several of its more famous brother, the W3-871 . Very good driver, but it sounds like a 3" driver. Small. Even with a sub. Nice - but small.

You would be better off with the 6.5" W6-789 or the slightly smaller 5.25" W5-704 that Cal pointed out. That way you can keep most of the music coming from one driver; just fill in on the top and bottom. If you cross either driver up high, say ~5K, then just use one of the little Dayton Neo tweeters. I doubt you would have to move it around, it might be perfectly happy to stay right beside the main driver.


At what frequency do we call it a "sub-woofer" as opposed to a "woofer"?

Subs usually operate under 150Hz.

I understand your side firing sub, don't want to wake the neighbors below! So, on the side it is! (Though it probably won't matter.)

So here's a question for you. Where do you plan to put the electronics? On the shelf of one of the tables? Somewhere else? Remember that if you put a plate amp in the table for the sub, it will need power. Maybe you could run power to each table, and then build in a nice looking AC outlet in each table for amps, CD player, Lava Lamps and such. Wouldn't that be fun? This thing is going to have Major WAF.
 

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And I assume you're Bob. Thanks Uncle Bob! When it wasn't listed at parts express I assumed it wasn't available... awesome. Where did you find this?

Tang Band has a wide selection,may of which look very similar. I haven't read a bad review of any, but I have read one person who like the Babboo TB over it's non-bamboo sibling. I have to say, even choosing within the tangband line is daunting. What do those phase plugs do anyway?

You mention that it sounds like a 3 inch driver, what does that sound like? I'm not being a wise guy. I was assuming that I would get the best overall sound by getting speakers that focus on a particular range. Is there no disadvantage to getting a 6" speaker for such a wide range? Will is still have nice tight mids if it can do some bass? 6" is bigger then the woofer in the Wharfedales.

I don't have a really good feel for the sound of the frequencies and what goes where, but I have originally thought of crossing over up near 300Hz with a 3 inch driver. But with the design concerns it sounds like that's not a good idea.

Have you used the little Dayton tweeters? I like that press fit one. I was thinking I could easily create a little spere or cylinder to embed it in that could sit on the shelf, ot maybe hang from the top on a swivel mount. I'm assuming tweeters are fairly insensitive to the enclosure.

I understand your side firing sub, don't want to wake the neighbors below! So, on the side it is! (Though it probably won't matter.)

do you mean because it's not directional, so it doesn't matter where I face it they will hear it?

thanks again for all the help.

-mark
 
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Hey Mark,
You should have a look at this project over at Part Express: Magna.

Way bigger than what you want, but a similar concept. Uses the W6-789 as a mid.

One thing that hasn't been talked about - how big will the tables be? From your drawing they look big, but maybe they aren't. Can you give aprox. dimensions?

As for big drivers vs. small drivers, it's a matter of taste. Big drivers do it for me, they sound more real to me than the little guys. The small drivers don't sound bad, but they always sound "small". I don't know how to explain it better. You can drive down the road at 80 MPH in a little EconoCar, or in a Cadillac. Same road, same speed, same direction. It just won't feel the same.

That said, small drivers do many things very well indeed. You'll find lots of guys here who love 'em. But maybe I spent too much time in Pro audio - an 8" driver is a mid there! It's just a matter of taste at home. I like big drivers even for the type of music I mostly listen to: Jazz, chamber music, little girls with guitars, crooners. And when I put on a full symphony - well....

You're right that Tang Band has a lot to choose from. But choose you must. And you've already got 3 good candidates: W6-789 that I like - W5-704 that Cal suggested or one of the little bamboo drivers. All of them will sound really good, no worries. The phase plug helps keep the different frequencies "in phase”.

Because you want a non-direct woofer, you'll be crossing as low as possible, so a bigger driver will work better - but it doesn't need to be huge. Bass in a room can be somewhat omni directional, so your neighbors below will get a dose if it's loud, no matter what. But yeah, hitting their ceiling with it will likely be louder than hitting your wall. ;) Down firing subs are popular, they tend to fill the room with bass everywhere.

The tweeter doesn't need a box, it's built in. At its lower frequencies it will like having a baffle behind it. At 5Khz, you don't need much, maybe 3" or so.

So how big are those tables going to be?
 
you're right, I never said how big, sorry. Also, in the picture they look more square then they will be. Of course there is a lot of room for adjustment on the speaker size, but the maximum size of the top platform is 14x34" and the top will be at about 24" of 25" off the floor. The funny thing is that my old floor standers are 12x14x24, which is about what I expect these to be, or slightly smaller.

Yeah, those three tang bands look good. I tell you, the three are tugging at me in three dimensions for different reasons. I plan to do some modeling first, so we'll see how that goes. I think it will be awhile b4 I buy the drivers. I think the Dayton neo tweeter isn't as high quality as the tang band mids, do you think this will be a drawback? Seas has some nice small diameter tweeters. Also, I was thinking that since the Dayton ND20FA is inexpensive enough and smal enough that I could easily recut the hoel and put something else in if I wanted something better.

As for the down firing sub, it sounds really neat. Would it make any sense to go with 8 when 10 or 12 would fit? Here's a thought, if I put the speaker box directly belor the top platform withou a space and installed a shelf near the floor would this deflect the energy of the downfiring woofer from the floor?

This is a lot of fun, thanks again Bob and everyone for all the help. Believe it or not I have to be mousing with my left hand today because I've been doing so much web browsing on this project that I have a pinched nerve in my right shoulder. And, I generally spend 6 hours a day on the PC. That's insane!

cheers all,
mark

p.s.
would anyone who is a 3-4" midrange midrange drive fan be willing to weigh in on why?
 
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Hi Mark,
OK - they are smaller than imagined. I must have been thinking "coffee table" not "end table."

But still, you should be able to get 2ft^3 out of them.
Not too bad.

My opinion:
Woofer DAYTON DC200-8 8"
MIDRANGE Tang Band W5-704
TWEETER Dayton Neo.

Crossover at about 110Hz and 5KHz.

Should get you were you want to go.
 
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