Hi everyone,
I would like to build a speaker for each of my daughters for Christmas next year but I'm not sure I know how to. I can build the boxes but apparently have no clue on the speaker components. I would like to build a box approximately 18"W x 13"H x 10"D to house all speakers in one unit...sort of like a semi-portable boombox
I came across a 4-year-old thread on another site where the OP provided a parts list for a shelf boombox. The following is the list provided in that thread:
The questions I have are specifically on the crossovers:
I contacted the tech support person at Parts Express for assistance but unfortunately didn’t provide the help I needed.
I would greatly appreciate any help you can provide.
I would like to build a speaker for each of my daughters for Christmas next year but I'm not sure I know how to. I can build the boxes but apparently have no clue on the speaker components. I would like to build a box approximately 18"W x 13"H x 10"D to house all speakers in one unit...sort of like a semi-portable boombox
I came across a 4-year-old thread on another site where the OP provided a parts list for a shelf boombox. The following is the list provided in that thread:
- (1) Fosi BT10A 50w x2 Bluetooth amp
- (2) HiVi M6N 6” Midbass woofers 8 Ohm
- (2) Visaton SC5-8 1/2” tweeters 8 Ohm
- (2) 4,000hz 12db/octave crossovers
- (1) Parts Express 2” adjustable port tube
The questions I have are specifically on the crossovers:
- I’m not sure if the crossover specified on the above parts list is a high pass, low pass or 2-way. I’m thinking it is a 2-way but want to be sure.
- If a 2-way crossover is recommended, then what frequency and impedance size crossover should I get? The mid-bass woofers and tweeters are 8 ohms. Should this be taken into account when choosing a crossover?
- How many 2-way crossovers do I need? Can I use a single 2-way crossover and connect it to all speakers, or should I use 1 crossover per set of tweeter and mid-bass woofer?
I contacted the tech support person at Parts Express for assistance but unfortunately didn’t provide the help I needed.
I would greatly appreciate any help you can provide.
We can give recommendations, but take them with a grain of salt. A crossover is unique to the speaker and nothing you buy off the shelf can be exact.
The filters you link to will work with the tweeters. You'll need one for each. This is the minimum needed to operate these, since they will save the tweeters from being overdriven.
Next you'll want level setting resistors to balance them with the mids. You'll want a low pass filter for each mid.
You may also want a baffle compensation element which you won't likely find off the shelf.
The filters you link to will work with the tweeters. You'll need one for each. This is the minimum needed to operate these, since they will save the tweeters from being overdriven.
Next you'll want level setting resistors to balance them with the mids. You'll want a low pass filter for each mid.
You may also want a baffle compensation element which you won't likely find off the shelf.
You have bought a high pass crossover. This protects the tweeter but does not keep the woofer or midrange from trying to reproduce frequencies up in its breakup zone. Also does not keep amp from pumping too many watts into the woofer which comes out as heat - and blows output transistors on the amp if the combination is below the impedance rating of the amp. Where the driver impedance peaks (see manufacturer chart) the amp and driver are not going to reproduce those frequencies anyway. Ie, at or below "Fs".
P-E also sells 2 and 3 way crossovers. I did not crawl through the whole list, but here is a 3 way crossover that separates at 500 hz and 4000 hz. https://www.parts-express.com/Dayton-Audio-XO3W-500-4K-3-Way-Crossover-500-4-000-Hz-260-152
One picks crossover frequencies to screen out frequencies where the flat wall response of a woofer or midrange gets bumpy (breakup) or the driver has an impedance peak (low frequency limit). Bumpy response causes distortion. I'll let you look up the frequency responses of your drivers and imagine matching them in your mind. The P-E crossovers usually have a 12 db/octave rollover each way. They also have a watt limit with the 50 w variety being the cheapest. Watch the 4 ohm or 8 ohm design spec of package crossovers.
If 3 drivers have different 1w1m volume, you have to also insert resistors on the high efficiency drivers to pull them down to the level of the low efficiency drivers. I use a sack of 1 ohm 10 watt wirewound resistors myself instead of unreliable (due to oxidation of the wiper) L-pads.
AllenB mentions baffle step, which is a bass boost added to speakers set at the front of a deep stage or in the middle of a room. Assuming the audience is in front of the speaker, bass wraps around the back below about 400 hz to pump the air behind the speaker. This sound is "lost" since there are no paying customers back there. Baffle step is usually 3 or 6 db bass boost. I push my speakers against a hard wall myself, and let the wall prevent bass leaking out the back to no use. Corner location boosts the bass naturally even more.
Suggest you pick up David Weems Designing Building and Testing speakers, a book I picked up used for $11 ebay.
Testing involves a flat response microphone, an input suitable for that microphone, and software on a PC or laptop with a sound input. Also a non-echoic room (expensive), a microphone stuffed right in front of each driver individually (must be omni to do that), or as I do it, outside at night against the cinder block wall of my garage. Free testing software is REW, room effect wizard. I use a $27 cardioide condensor mike 2 m from the whole speaker, at about ear level, a $35 used PV8 mixer with phantom power (required for condensor mikes) and the blue stereo input of my PC. I have an Intel chipset. Some people swear by sound appliances that convert to USB, but with good ones being up in the $200+ range, I do without. I'm not looking for 0.0x% distortion, below 5% would be nice.
Best of fortune in your endeavors.
P-E also sells 2 and 3 way crossovers. I did not crawl through the whole list, but here is a 3 way crossover that separates at 500 hz and 4000 hz. https://www.parts-express.com/Dayton-Audio-XO3W-500-4K-3-Way-Crossover-500-4-000-Hz-260-152
One picks crossover frequencies to screen out frequencies where the flat wall response of a woofer or midrange gets bumpy (breakup) or the driver has an impedance peak (low frequency limit). Bumpy response causes distortion. I'll let you look up the frequency responses of your drivers and imagine matching them in your mind. The P-E crossovers usually have a 12 db/octave rollover each way. They also have a watt limit with the 50 w variety being the cheapest. Watch the 4 ohm or 8 ohm design spec of package crossovers.
If 3 drivers have different 1w1m volume, you have to also insert resistors on the high efficiency drivers to pull them down to the level of the low efficiency drivers. I use a sack of 1 ohm 10 watt wirewound resistors myself instead of unreliable (due to oxidation of the wiper) L-pads.
AllenB mentions baffle step, which is a bass boost added to speakers set at the front of a deep stage or in the middle of a room. Assuming the audience is in front of the speaker, bass wraps around the back below about 400 hz to pump the air behind the speaker. This sound is "lost" since there are no paying customers back there. Baffle step is usually 3 or 6 db bass boost. I push my speakers against a hard wall myself, and let the wall prevent bass leaking out the back to no use. Corner location boosts the bass naturally even more.
Suggest you pick up David Weems Designing Building and Testing speakers, a book I picked up used for $11 ebay.
Testing involves a flat response microphone, an input suitable for that microphone, and software on a PC or laptop with a sound input. Also a non-echoic room (expensive), a microphone stuffed right in front of each driver individually (must be omni to do that), or as I do it, outside at night against the cinder block wall of my garage. Free testing software is REW, room effect wizard. I use a $27 cardioide condensor mike 2 m from the whole speaker, at about ear level, a $35 used PV8 mixer with phantom power (required for condensor mikes) and the blue stereo input of my PC. I have an Intel chipset. Some people swear by sound appliances that convert to USB, but with good ones being up in the $200+ range, I do without. I'm not looking for 0.0x% distortion, below 5% would be nice.
Best of fortune in your endeavors.
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If the building is for educational purposes, I'd use an existing well sounding design. For reference. A box that is handleable, that has plus-minus binding posts, a cable for connecting to the amplifier, which has colored binding posts too. A box that has a grill for protection, and the grill frame can be detached if wanted.
The boxes are two, like the ears, because of the two channels.
The boxes are two, like the ears, because of the two channels.
Of course I would start with vlnyl and tube amps. A little bit of history.. then physics with understanding of basics from Kirkhoff to Nyquist and so on. It should be fun! 🙂
I'd build the smallest kit from SB acoustics, the one with the 12 PAC or CAC.
In Usa there are 2-3 major vendors and the parts are ready on stock, it would cost about 100$ per speaker (plastic baskets are economic, if preferred..) if the box is made with MDF.
State of the art box with external crossovers and so on might cost 10X
In Usa there are 2-3 major vendors and the parts are ready on stock, it would cost about 100$ per speaker (plastic baskets are economic, if preferred..) if the box is made with MDF.
State of the art box with external crossovers and so on might cost 10X
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Trying to help somebody who already jumped into the lake and NOW found he can't swim 🙂
Somewhat late to restart from zero, read books, etc. ; let's try to meet the (not too critical) goal, stated as "Dad's present to Daughters" 🙂 the best we can, with what's available.
Out of what you bought, only the high pass crossover is unusable (wrong impedance and frequency).
Since you are already into Parts Express, you will need :
* Two 2 way crossovers (one per woofer/tweeter pair).
Your Tweeters "can" reach 4 kHz, recommended is >5kHz, closest available is 4.5kHz ... should do. [shrug]
https://www.parts-express.com/Dayton-Audio-XO2W-4.5K-2-Way-Crossover-4-500-Hz-260-148?quantity=1
Just build the cabinet you want, guess size is dictated by space you have available.
A closed box is easier, maybe a kind soul can calculate tuning tube dimensions (length) using your cabinet volume and a piece of that tube if a tuned cabinet is preferred.
There are some box volume suggestions in the woofer/mid page.
I guess you will build a single BEEG stereo powered cabinet with everything inside, sort of a glorified boom box on steroids.
Search and read the Boominator thread, it can give you some build and packing ideas..
Somewhat late to restart from zero, read books, etc. ; let's try to meet the (not too critical) goal, stated as "Dad's present to Daughters" 🙂 the best we can, with what's available.
Out of what you bought, only the high pass crossover is unusable (wrong impedance and frequency).
Since you are already into Parts Express, you will need :
* Two 2 way crossovers (one per woofer/tweeter pair).
Your Tweeters "can" reach 4 kHz, recommended is >5kHz, closest available is 4.5kHz ... should do. [shrug]
https://www.parts-express.com/Dayton-Audio-XO2W-4.5K-2-Way-Crossover-4-500-Hz-260-148?quantity=1
Just build the cabinet you want, guess size is dictated by space you have available.
A closed box is easier, maybe a kind soul can calculate tuning tube dimensions (length) using your cabinet volume and a piece of that tube if a tuned cabinet is preferred.
There are some box volume suggestions in the woofer/mid page.
I guess you will build a single BEEG stereo powered cabinet with everything inside, sort of a glorified boom box on steroids.
Search and read the Boominator thread, it can give you some build and packing ideas..
