I'm starting a new project and would appreciate some input from those with more experience than me.
Goal.
To design and build a stereo system for low to moderate listening levels, that will produce flat (ish) frequency response down to 35Hz.. that is small enough to take into work without drawing a bunch of attention to myself.
Budget <$300.
This will be a 2 way bookshelf + subwoofer system utilizing fountek FR88ex mids (probably) and Vifa XT25SC90-4 tweets. I am undecided on a sub woofer yet, but would like to stick with as small of a woofer as possible. 6.5 inch or less.
I wonder how Dayton Audio ND105-8's will perform as a sub woofer in a bass reflex box, or something of the sort.
I have so little free time on a computer that will allow me to do some modeling of speaker boxes, so I would appreciate any technical input I can get on the matter of a box for that particular woofer.
I do not have a problem building a large box, and a passive radiator may be a viable option, I just don't want to lug in an enormous box with a 12 inch woofer in it. my boss would probably ban radios immediately as soon as he saw it. 😀 ANYWAYS!
Goal.
To design and build a stereo system for low to moderate listening levels, that will produce flat (ish) frequency response down to 35Hz.. that is small enough to take into work without drawing a bunch of attention to myself.
Budget <$300.
This will be a 2 way bookshelf + subwoofer system utilizing fountek FR88ex mids (probably) and Vifa XT25SC90-4 tweets. I am undecided on a sub woofer yet, but would like to stick with as small of a woofer as possible. 6.5 inch or less.
I wonder how Dayton Audio ND105-8's will perform as a sub woofer in a bass reflex box, or something of the sort.
I have so little free time on a computer that will allow me to do some modeling of speaker boxes, so I would appreciate any technical input I can get on the matter of a box for that particular woofer.
I do not have a problem building a large box, and a passive radiator may be a viable option, I just don't want to lug in an enormous box with a 12 inch woofer in it. my boss would probably ban radios immediately as soon as he saw it. 😀 ANYWAYS!
Low bass needs to move air, but I don't see that happening with a 6.5 inch.
How about two 8 inch woofers mounted face-to-face (isobaric)? This permits the box to be half the volume needed for a single woofer.
How about two 8 inch woofers mounted face-to-face (isobaric)? This permits the box to be half the volume needed for a single woofer.
Isobaric or bandpass.
You could also use a high excursion small sub in an undersized box and use a linkwitz transform to boost the low bass.
low bass at ear blistering levels needs to move air. Technically all bass needs to move air, but you catch my drift. He is not looking at concert sound pressure levels. A quality 6.5 "subwoofer" in a properly designed bandpass can achieve good sensitivity and low-end response.
bradsworth, at what frequency do you anticipate you'd want to cross over to the satellite/high-freq. speakers?
I think 8's would be much to heavy and large to be inconspicuous. although I would prefer it. I also want to keep my power requirements down, so a single woofer is preferred. I think I will be safe crossing my mids down to 150Hz or so, I may go with a larger midrange to get closer to 80 or 90Hz if it will significantly help my bass extension with the subwoofer. I really want to base this entire design around accurate music reproduction. specifically in the bass frequencies, where my current work radio completely lacks. For pure entertainment purposes, I will reveal what it is. 😱 don't make too much fun of me though
A 10 or so year old pioneer head unit, powered by an old computer's power supply, driving 2 kicker component speakers I took out of a buddy's car when I upgraded his sound system. The entire thing cost my exactly nothing to build. save the hour it took to build and enclosure out of 3/8th inch plywood and some soldering. oh yea, and the duct tape and sharpie to make it look like an 90's boombox. It is my temporary solution until I have a decent system put together 😀 I was surprised how well it was received. everyone at work wants one. hahaha
A 10 or so year old pioneer head unit, powered by an old computer's power supply, driving 2 kicker component speakers I took out of a buddy's car when I upgraded his sound system. The entire thing cost my exactly nothing to build. save the hour it took to build and enclosure out of 3/8th inch plywood and some soldering. oh yea, and the duct tape and sharpie to make it look like an 90's boombox. It is my temporary solution until I have a decent system put together 😀 I was surprised how well it was received. everyone at work wants one. hahaha
Wow, thank you for leading me to that site. I found it a while back, but havn't been able to relocate it. That is pretty much exactly what I'm looking for. With mild modifications it should work well.
I have two of those TB subwoofers. Bought them before the price of Neo skyrocketed. Too bad you can't get them for the $40 listed in that build list, lol. The ceramic version is $4X.00 though.
What environment is your work? this is almost contradictory, in that you don't want attention but you want good bass response... will the environment be conducive to bass reproduction?
It takes 4 times the displacement (or excursion) to maintain the same SPL for every octave lower you go.
Here is a calculator that will help you,
Piston Excursion calculator
Yes, an isobaric setup does allow you to use a box that is half the volume of what it would otherwise take for that of a single woofer.
But, this does nothing to increase displacement when adding the second driver and doesn't have the advantage of increasing the displacement by adding the second woofer.
Many like this type of setup, But IMHO it is a waste of a driver and the extra power required to drive it.
Increasing Displacement is the only way to increase the SPL
jer 🙂
Here is a calculator that will help you,
Piston Excursion calculator
Yes, an isobaric setup does allow you to use a box that is half the volume of what it would otherwise take for that of a single woofer.
But, this does nothing to increase displacement when adding the second driver and doesn't have the advantage of increasing the displacement by adding the second woofer.
Many like this type of setup, But IMHO it is a waste of a driver and the extra power required to drive it.
Increasing Displacement is the only way to increase the SPL
jer 🙂
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Now we are getting to the heart of the matter, the environment, and specifically the boss and the boss' own attitude toward a nice little sub. You could just ask him point blank, but if there's already a hint of resistance or chance of getting fired then don't bring anything.
But if you want to take a chance on being the cool kid at work for once, young Bradsworth, here's what you do: Discretely determine your boss' receptiveness toward one for his own office. Then if he is, take up a collection from your coworkers telling them it's some appreciation gift or whatnot, and then make another sub for him. Instant brownie points all around!
PS. Use at least an 8 inch...
surely contradictory, especially when taking Fletcher Munson curves into consideration..
I"m more worried about drawing attention to myself walking through security than when actually playing music. I have a corner formed by a cubicle wall and a filing cabinet that may reinforce the bass slightly. but the ceiling and other walls are 100+feet away. my boss's office is a few hundred feet away in a completely separate room. I"m not concerned about moderate listening levels disturbing anyone else.
And I don't know how I feel about that being the cool kid at work for once comment, i'm always the cool kid
. hahaha... Just kidding 😛
I would think if I keep the sub only a few feet away and at head height I shouldn't need all that much surface area, because I will not need very high spl.
And I don't know how I feel about that being the cool kid at work for once comment, i'm always the cool kid
I would think if I keep the sub only a few feet away and at head height I shouldn't need all that much surface area, because I will not need very high spl.
I get fair but not super deep bass out of my desk top system down to about 35Hz to 45HZ or so at maximum SPL of about 95db using a sealed 5 1/4" woofer
I do have to use added filtering and the excursions do get very extreme at this level but it is good enough for for good sounding music.
Make sure that you choose a driver with the highest Xmax you can because of this.
At the lowest frequency's I am getting about 4 to 6mm peak (one way) of excursion and I am sure it is more than what the driver was designed or rate for.
Parts Express had a few drivers that would have been perfect for your application but I think that they are all sold out of them now.
I just found this one that two of them might work well,
Tang Band W5-876SE 5" Shielded Woofer 16 Ohms 299-135
Here is a picture of what I am working with and the frequency response as well.
Don't let the drop off fool ya, drums and bass sound very punchy and clean as long as it is at a reasonable level (90db) and EQ'd properly.
At less than 2 feet away 95db is quite loud and I believe the EQ's were set flat for that measurement.
But, like I said it takes the driver to the extremes of its Xmax at about 40hz.
I also have to 5.5" bose drivers similar to the PE drivers that were in dual chambered box a that perform well also.
The original box sounded muddy but the drivers themselves sound great for such an application.
You might try a small TL type of enclosure with the PE drivers.
By Small I mean a small box and a long line inside of it like the Bose (there's that word again!!) Wave Radio system.
FWIW
jer 🙂
P.S. This was an earlier picture and since then I have sealed up that port as they weren't tuned right from the factory.
I found this out after measuring the TL parameters of the driver and they sound much better sealed especially when under high excursions.
I do have to use added filtering and the excursions do get very extreme at this level but it is good enough for for good sounding music.
Make sure that you choose a driver with the highest Xmax you can because of this.
At the lowest frequency's I am getting about 4 to 6mm peak (one way) of excursion and I am sure it is more than what the driver was designed or rate for.
Parts Express had a few drivers that would have been perfect for your application but I think that they are all sold out of them now.
I just found this one that two of them might work well,
Tang Band W5-876SE 5" Shielded Woofer 16 Ohms 299-135
Here is a picture of what I am working with and the frequency response as well.
Don't let the drop off fool ya, drums and bass sound very punchy and clean as long as it is at a reasonable level (90db) and EQ'd properly.
At less than 2 feet away 95db is quite loud and I believe the EQ's were set flat for that measurement.
But, like I said it takes the driver to the extremes of its Xmax at about 40hz.
I also have to 5.5" bose drivers similar to the PE drivers that were in dual chambered box a that perform well also.
The original box sounded muddy but the drivers themselves sound great for such an application.
You might try a small TL type of enclosure with the PE drivers.
By Small I mean a small box and a long line inside of it like the Bose (there's that word again!!) Wave Radio system.
FWIW
jer 🙂
P.S. This was an earlier picture and since then I have sealed up that port as they weren't tuned right from the factory.
I found this out after measuring the TL parameters of the driver and they sound much better sealed especially when under high excursions.
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I'd go with a single Tang Band 6.5" subwoofer.
You won't run out of output with one of those. At those listening levels, you could probably eq to <30Hz without excursion being an issue - they'll move ~1" p/p, which is roughly similar in output to a 12"er moving 1/4" p/p. Still gonna be pretty loud 😀
I'd advise that these drivers can be very power hungry. I've driven a 275w/ch amp to clipping with those little guys - they just sit there and take it. At those power levels, the voice coils are very well ventilated 😉
Chris
You won't run out of output with one of those. At those listening levels, you could probably eq to <30Hz without excursion being an issue - they'll move ~1" p/p, which is roughly similar in output to a 12"er moving 1/4" p/p. Still gonna be pretty loud 😀
I'd advise that these drivers can be very power hungry. I've driven a 275w/ch amp to clipping with those little guys - they just sit there and take it. At those power levels, the voice coils are very well ventilated 😉
Chris
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