I want to build a pair of speakers for my "fresh air" shop. Here is what I am currently using for my sounds and where I am starting from
I call it my speaker tree, lol. I am looking to upgrade….
I bought the following so far or my start so to say,
- Lepai Tripath TA2020 Class-T amp
-Bose 901 Drivers off of ebay. They are about 4.5" in diameter.
I am looking for an opinion on what time of enclosures to build. I really like the horn designs but I think that I will need a bass reflex type of cabinet. So I am looking at the
Floorstander Mk ii from Planet 10. I plan on building the speakers out of pine and fir from my local homecenter. I have been reading a lot of forums but I am lost when it comes to some of these charts etc.
Thanks,
Gus
I call it my speaker tree, lol. I am looking to upgrade….
I bought the following so far or my start so to say,
- Lepai Tripath TA2020 Class-T amp
-Bose 901 Drivers off of ebay. They are about 4.5" in diameter.
I am looking for an opinion on what time of enclosures to build. I really like the horn designs but I think that I will need a bass reflex type of cabinet. So I am looking at the
Floorstander Mk ii from Planet 10. I plan on building the speakers out of pine and fir from my local homecenter. I have been reading a lot of forums but I am lost when it comes to some of these charts etc.
Thanks,
Gus
The TS parameters are not published, unless some hobbyist found them and posted. It matters which version of the Bose 901 they are out of. Early drivers are likely to have foam surrounds that are rotted or rotting - a common problem in all foam surrounds.
If they have cloth surrounds, ur ok.
You can measure the T/S parameters yourself, it's not that hard.
The original design of the 901 used a sealed box with massive amounts of LF and HF boost to get a "flat" response that was also wide range. You can count on these speakers to be more or less "midrange" drivers without EQ.
I suggest you plan on adding in a tweeter at ~1.5 - 2kHz. No big deal.
One way to go is with a single line source, one driver on top of the next... the only question will be the box volume, which will depend on the T/S parameters. The ones you want are Fs, Qt and VAS.
So, regardless, and unless you plan on adding in EQ (if you stack them as a line source, then you have an "improved" version of the 901) you will then need a speaker or speakers for the BASS...
Btw, you will use a series parallel wiring arrangement, like BOSE did originally...
Alternately you can put each driver in its own volume and stack or array them...
Regardless, you have a project now that will open the door to you about speakers, speaker design and fun!
_-_-bear
If they have cloth surrounds, ur ok.
You can measure the T/S parameters yourself, it's not that hard.
The original design of the 901 used a sealed box with massive amounts of LF and HF boost to get a "flat" response that was also wide range. You can count on these speakers to be more or less "midrange" drivers without EQ.
I suggest you plan on adding in a tweeter at ~1.5 - 2kHz. No big deal.
One way to go is with a single line source, one driver on top of the next... the only question will be the box volume, which will depend on the T/S parameters. The ones you want are Fs, Qt and VAS.
So, regardless, and unless you plan on adding in EQ (if you stack them as a line source, then you have an "improved" version of the 901) you will then need a speaker or speakers for the BASS...
Btw, you will use a series parallel wiring arrangement, like BOSE did originally...
Alternately you can put each driver in its own volume and stack or array them...
Regardless, you have a project now that will open the door to you about speakers, speaker design and fun!
_-_-bear
Thank you guys for you responces. I will try to look up all the infromation and direction that you have given me. But please forgive me if i come back with more questions. I am a total newbe to all of this. Some of bear's terms have me off tilt. lol.
here is the information that the seller gave...
For Sale is a Pair of Original Bose 901 series I or II full range 8 ohm driver speakers they will fit in most 901's. They are in excellent working condition, and have been tested, no buzzing or scraping. Ohm readings are 7.5 & 7.6 ohms, # 25-100441 24729 285206. No Dents, rips or tears no damage these and have the cloth surrounds so they will not get foam rot.
These are some of the best full range drivers out there, they just have that Fantastic Bose Sound & Bose Quality. Perfect for replacements or use in small monitors. These create an amazing soundstage and unbelievable sound quality and detail for single driver setups. Also excellent for mid range or extended frequency mid-bass. 4 1/8" cutout diameter, 4 5/8" OD, 5" diagonally, 1 3/4" depth
here is the information that the seller gave...
For Sale is a Pair of Original Bose 901 series I or II full range 8 ohm driver speakers they will fit in most 901's. They are in excellent working condition, and have been tested, no buzzing or scraping. Ohm readings are 7.5 & 7.6 ohms, # 25-100441 24729 285206. No Dents, rips or tears no damage these and have the cloth surrounds so they will not get foam rot.
These are some of the best full range drivers out there, they just have that Fantastic Bose Sound & Bose Quality. Perfect for replacements or use in small monitors. These create an amazing soundstage and unbelievable sound quality and detail for single driver setups. Also excellent for mid range or extended frequency mid-bass. 4 1/8" cutout diameter, 4 5/8" OD, 5" diagonally, 1 3/4" depth
pictures?
the seller's hype is just hype... except as noted: "excellent for mid range or extended frequency mid-bass"...
You can figure this stuff out... there is a lot of information here on DIYAudio if you search and read... as well as a ton of tutorial sites online... feel free to ask questions, but please do try to figure it out first?
_-_-bear
the seller's hype is just hype... except as noted: "excellent for mid range or extended frequency mid-bass"...
You can figure this stuff out... there is a lot of information here on DIYAudio if you search and read... as well as a ton of tutorial sites online... feel free to ask questions, but please do try to figure it out first?
_-_-bear
Gus,
Your open air shop--aka under an overhang to work on stuff and listen to tunes? Since you're playing with a T-amp, I'm assuming a simple system that gives decent sound at a decent volume.
I just built my garage speakers--fed with a old receiver pushing 45 watts per channel. Since the garage has metal walls--I wanted something that would overpower reflections, be very efficient, give a very tall sweet spot, unique and ugly as sin. Next thing I know, there are a pair of 6 foot 2 inch tall vertical line arrays in the place and it does do what I want it to do. It sounds the same if I'm standing, sitting or laying on the floor so goal achieved.
Are you trying to build line arrays with 8 Bose 4.5" speakers per side or just prefer to use one or two of them per box? Arrays need EQ and if running full ranges--a ton of EQ! If it is only one or two per side, I'd go with something else. The low amount of power you're playing with leads me to something more along the lines of a PA speaker. Use one of those 12" "full-ranges" with a helper tweeter and a single capacitor for a very efficient speaker that is simple to build, sounds decent and gives a "big sound".
The full-range guys like the combo of an Eminence Beta 12 LTA ($65 each) crossed over at around 8 KHz to a single Fostex "super tweeter" ($43 each). It can be put in a 1.75 cubic foot sealed box, ported boxes or the giant BiB horns.
Eminence Beta-12LTA 12" Full-Range/PA Driver
Fostex FT17H Horn Super Tweeter: Madisound Speaker Store
If cost is an issue, the Pioneer AHE60 horn loaded tweeter is also a good match--$12 each.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=270-050
If you want clarity above all else, and the cost is not an issue--get the Fostex FT-17. I figure these speakers will be sitting outside so the Pioneers might be a better idea to prevent theft.
I was going to build the Beta12/FT-17 system in a BiB horn type enclosure but got side tracked with vertical line arrays. Went with the arrays since that design is the best for marginal spaces--my garage for instance.
Maybe your desire is a pair of single full-range speakers for simplicity? If so, look at Fostex, Mark Audio, Fountek, Tangband just to name a few.
What is your budget?
Your open air shop--aka under an overhang to work on stuff and listen to tunes? Since you're playing with a T-amp, I'm assuming a simple system that gives decent sound at a decent volume.
I just built my garage speakers--fed with a old receiver pushing 45 watts per channel. Since the garage has metal walls--I wanted something that would overpower reflections, be very efficient, give a very tall sweet spot, unique and ugly as sin. Next thing I know, there are a pair of 6 foot 2 inch tall vertical line arrays in the place and it does do what I want it to do. It sounds the same if I'm standing, sitting or laying on the floor so goal achieved.
Are you trying to build line arrays with 8 Bose 4.5" speakers per side or just prefer to use one or two of them per box? Arrays need EQ and if running full ranges--a ton of EQ! If it is only one or two per side, I'd go with something else. The low amount of power you're playing with leads me to something more along the lines of a PA speaker. Use one of those 12" "full-ranges" with a helper tweeter and a single capacitor for a very efficient speaker that is simple to build, sounds decent and gives a "big sound".
The full-range guys like the combo of an Eminence Beta 12 LTA ($65 each) crossed over at around 8 KHz to a single Fostex "super tweeter" ($43 each). It can be put in a 1.75 cubic foot sealed box, ported boxes or the giant BiB horns.
Eminence Beta-12LTA 12" Full-Range/PA Driver
Fostex FT17H Horn Super Tweeter: Madisound Speaker Store
If cost is an issue, the Pioneer AHE60 horn loaded tweeter is also a good match--$12 each.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=270-050
If you want clarity above all else, and the cost is not an issue--get the Fostex FT-17. I figure these speakers will be sitting outside so the Pioneers might be a better idea to prevent theft.
I was going to build the Beta12/FT-17 system in a BiB horn type enclosure but got side tracked with vertical line arrays. Went with the arrays since that design is the best for marginal spaces--my garage for instance.
Maybe your desire is a pair of single full-range speakers for simplicity? If so, look at Fostex, Mark Audio, Fountek, Tangband just to name a few.
What is your budget?
Why do you say that arrays require EQ?
Their response is essentially that of a single driver - no worse, no better.
The BOSE drivers would need EQ if you wanted "full range" response, but if they are augmented with a woofer and a tweeter - not, and you get pretty good sensitivity plus lower distortion and a single midrange at the same SPL... generally speaking.
The other alternatives are viable though...
_-_-bear
Their response is essentially that of a single driver - no worse, no better.
The BOSE drivers would need EQ if you wanted "full range" response, but if they are augmented with a woofer and a tweeter - not, and you get pretty good sensitivity plus lower distortion and a single midrange at the same SPL... generally speaking.
The other alternatives are viable though...
_-_-bear
IIRC the old 901 driver has Re around 1 ohm. Here's unequalized response of one of my 901's outdoors with mic: facing the single driver, then 8 driver array, then with the cabinet near a house wall with mic facing the single driver. The other graph is the EQ box response. This is the old/sealed 901 with cloth surround drivers.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
He did mention horn loaded enclosures so maybe a Fostex would work better for what he wants? The 6.5 inch Fostex is quite loud and there are all sorts of plans on the full-range forum for those drivers. If he adds a subwoofer to match up to 6.5 inch Fostex full-ranges, the little T-Amp should provide decent sound and have enough grunt for BBQ's etc. Even without a sub, it should be more than enough for basic background music out on the patio.
As far as multiples of speakers not changing their sound character, all is not well in array land so it is EQ to the rescue. Knowing this before I started, I went with the 2 way line array to limit the amount of EQ required. Tweeter padding to adjust the highs, subwoofer to actively bring up the bass does minimize large EQ swings and I can "get away" with a 1 octave EQ.
Interesting build using 24 3.5" full ranges in a line array--the frequency response changes drastically VS a single driver. Beware the -3dB/Oct tilt!
The Murphy Corner-Line-Array Test Results
I only purchased 2 bose drivers off of ebay. I was looking to keep it simple and just have 2 speakers. I was even thinking about bolting the little amp to one of the speakers so I could move around easier. As I am reading all of these great replies I am now thinking about adding a woofer for the bass that I want. Of course I would like to add it to 1 of the 2 speaker cabinets. There really wasn't a budget set, but I didn't want to spend a lot of money on them because they would be staying outside under the house which is my roaming area when I am home. My house is built on cement blocks 8' up. Under the house is where I do my woodworking, grilling, chilling and drinking my brewskies.
I usually just hook up my zune or iphone to the computer speakers and go to work. I was looking to get away from the pc speakers and get something that has a little more kick but still be budget friendly. Whatever I build will stay outside all of the time. I would really hate to leave Fostex etc outside.
Bass reflex or back horn cabinets - from what I have read, the type of music I mostly listen to will depict the best cabinet for the drivers. I am thinking that back horn will be too much mid to highs without a sub. That is why I am thinking bass reflex. I am still intrigued with back horns for some reason. I wounder if those Telavox youtube videos have anything to do with it or they just look cool. Lol. The music I like to listen to is some jazz and rock but mostly I listen to chill, down tempo or trip-hop. I love it when the music sounds crisp, clean and deep.
TS frequencies - I have been looking that up, before I pull out my volt meter or buy a new one I am attempting to buy a Peak Instruments Woofer Tester off ebay. I just hope I can find someone with a floppy drive pc for the software, lol.
I usually just hook up my zune or iphone to the computer speakers and go to work. I was looking to get away from the pc speakers and get something that has a little more kick but still be budget friendly. Whatever I build will stay outside all of the time. I would really hate to leave Fostex etc outside.
Bass reflex or back horn cabinets - from what I have read, the type of music I mostly listen to will depict the best cabinet for the drivers. I am thinking that back horn will be too much mid to highs without a sub. That is why I am thinking bass reflex. I am still intrigued with back horns for some reason. I wounder if those Telavox youtube videos have anything to do with it or they just look cool. Lol. The music I like to listen to is some jazz and rock but mostly I listen to chill, down tempo or trip-hop. I love it when the music sounds crisp, clean and deep.
TS frequencies - I have been looking that up, before I pull out my volt meter or buy a new one I am attempting to buy a Peak Instruments Woofer Tester off ebay. I just hope I can find someone with a floppy drive pc for the software, lol.
Okay I don't know where this idea is comming from but it's been spread way too wide so I shall debunk it now. A rear loaded horn is the best way to get louder cleaner and deeper bass. A transmission line or bass reflex is an inferior solution to use when you are limited by size or woodwoking skills. BUT, to get superior performance from a horn it must be designed for the driver in it. So if you find the T/S parameters for these drivers I can design you harns that will give you bass performance that no BR or TL could even touch!
Well I modeled a nice horn for the replacement drivers PE has for the 901s. Should be close enough to spec that your drivers would perform similarly. How big do you want these things because if you make the horns big enough you shouldn't even need a subwoofer. I'm modeling 115db down to 50hz corner loaded, but they're like 70Liters internal volume.
brsanko - I am still out of town, when i get home hopefully i will have the speaker tester waiting on me. I will get the numbers for you. As far as speaker size goes, i would like to be able to move them around easily, lets see what you have.
On another note, I picked up some 6" woofers off ebay for $20. but the are 5ohm. the T amp is rated for 4 or 8 ohms, the bose drivers i have at home are 8 ohms i am assuming based on seller info. If i decided to go with a 3 way speaker can i use this with the T amp with a cross over? is there anyway to change the ohm of the speaker using a resister?
On another note, I picked up some 6" woofers off ebay for $20. but the are 5ohm. the T amp is rated for 4 or 8 ohms, the bose drivers i have at home are 8 ohms i am assuming based on seller info. If i decided to go with a 3 way speaker can i use this with the T amp with a cross over? is there anyway to change the ohm of the speaker using a resister?
The series l & ll were 4 bolt cloth surround 8 ohm drivers, black in colour like the ones you show. If you have 18 of them, wire 3 of them in series then take 3 sets of those and wire them parallel and you'll end up with 8 ohms on each side.
I agree with the others, don't try and use them for the bass. You will find it is among the muddiest sounding bass of any popular speaker in history. You can cross them over nice and low though and consider getting a plate amp to run the 6.5" woofers. If you use the speaker level input on the plate amp, you can then use the speaker level outputs which will have a built in high pass XO in most cases. You can then get a sensitive tweeter and cross it over high by using a very small capacitor (2, 1.5 or 1 mfd) You won't need a low pass on the Bose drivers just run them straight. You will have a system that gives plenty of oomph for not a lot of cash and it might actually sound OK.
I agree with the others, don't try and use them for the bass. You will find it is among the muddiest sounding bass of any popular speaker in history. You can cross them over nice and low though and consider getting a plate amp to run the 6.5" woofers. If you use the speaker level input on the plate amp, you can then use the speaker level outputs which will have a built in high pass XO in most cases. You can then get a sensitive tweeter and cross it over high by using a very small capacitor (2, 1.5 or 1 mfd) You won't need a low pass on the Bose drivers just run them straight. You will have a system that gives plenty of oomph for not a lot of cash and it might actually sound OK.
The cabinets got a little complicated in the later series'
Yes, see post 23 here for the EQ's
http://www.diyaudio.com/forums/multi-way/138083-bose-901-iv-serie.html
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