I am wanting to build a nice pair of speakers for a 2-channel system- no sub to be used here. In hopes of meeting my bass requirements while still keeping a relatively low cost, I am turning to cheaper pro drivers, namely Selenium and Eminence. I am concerned about the matching, though. I REALLY wanted to do a horn-loaded 3-way system, but money, space, and carpentry skills are lacking. So, I have resolved to do a simple, yet nice looking pair of box-type speakers. Stil wishing for 3-way, but the added driver puts too much extra in the expense area. SO, I have decided to do a 2-way system, and it is looking as though it will be crossed over at around 2000Hz. To be made up of the following:
one Eminence Alpha-12A 12" woofer OR one Selenium 12PW3CE 12" woofer
and one Selenium DH200H-M titanium compression horn tweeter
The enclosure will be about 3.5-ish cubic feet. About 14" wide x 12-18" deep x 30-38" tall. Not sure what all volumes those come out to be. Using the Parts Express speaker design software, he Eminence seems to have too high of an F3, while the Selenium is some 10-20 Hz lower. (I don't remember for sure what the difference was) All in all, which would be the best match? All parameters can be found at Parts Express, if they are needed. Also, if needed, I will be driving these speakers with a tube amp that puts out about 8 watts. After all is said and done, would I have een better off just buying a pair of Klipsch Heresy's? Or would these DIY speakers make me never think back upon the Heresy's? Thanks for the help.
one Eminence Alpha-12A 12" woofer OR one Selenium 12PW3CE 12" woofer
and one Selenium DH200H-M titanium compression horn tweeter
The enclosure will be about 3.5-ish cubic feet. About 14" wide x 12-18" deep x 30-38" tall. Not sure what all volumes those come out to be. Using the Parts Express speaker design software, he Eminence seems to have too high of an F3, while the Selenium is some 10-20 Hz lower. (I don't remember for sure what the difference was) All in all, which would be the best match? All parameters can be found at Parts Express, if they are needed. Also, if needed, I will be driving these speakers with a tube amp that puts out about 8 watts. After all is said and done, would I have een better off just buying a pair of Klipsch Heresy's? Or would these DIY speakers make me never think back upon the Heresy's? Thanks for the help.
trespasser_guy,
For a two-way system with a horn the top and a direct radiator on the bottom, you would be better off with an x-over in the 500Hz to 800Hz range. This is would be the home version of the classic VOT type speakers. Here’s a link that describes the Altec VOT’s
http://www.soundpractices.com/images/smallVOT.pdf
Here is a link on horns. From Tom Dunker’s site and his links, you’ll be able to find tons of info on horns
http://invalid.ed.unit.no/~dunker/horns.html
Jammin Jersey’s is just one place that sell used equipment. It would be a way get higher quality equipment and stay closer to your budget.
http://www.jamminjersey.com/speaker3.htm#Altec
Have fun,
Rodd Yamashita
For a two-way system with a horn the top and a direct radiator on the bottom, you would be better off with an x-over in the 500Hz to 800Hz range. This is would be the home version of the classic VOT type speakers. Here’s a link that describes the Altec VOT’s
http://www.soundpractices.com/images/smallVOT.pdf
Here is a link on horns. From Tom Dunker’s site and his links, you’ll be able to find tons of info on horns
http://invalid.ed.unit.no/~dunker/horns.html
Jammin Jersey’s is just one place that sell used equipment. It would be a way get higher quality equipment and stay closer to your budget.
http://www.jamminjersey.com/speaker3.htm#Altec
Have fun,
Rodd Yamashita
Well, let's take look at the woofers. You are using PA speakers for home use, I imagine, because your tube amp output is only 8 watts and you want sensitivity.
Here is the Alpha. It has the smoother response of the two through the midrange. I guess we could call this 94 dB through the midrange response. The big rise in sensitivity could be addressed, to a greater or lesser degree, with an inductor in series.
The Thiele-Small numbers give us a mixed picture. On the one hand, you end up with a pretty smooth, desirable Qtc of 1.15-a bit higher than the optimal range, but no too bad. On the other hand, your F3 is around 63.
I should point out that most DJ boxes are 3 cubic feet, usually ported, (but so what), and have an F3 around 60 Hz. This is how they make their living, and most people find that to be an aceptable F3, even though you would like something deeper for home listening. If 60 Hz sounded "tinny", DJ's would have to use equipment that goes lower, and they don't. So you can slide by there.
Here is the graph of the Alpha 12:
Here is the Alpha. It has the smoother response of the two through the midrange. I guess we could call this 94 dB through the midrange response. The big rise in sensitivity could be addressed, to a greater or lesser degree, with an inductor in series.
The Thiele-Small numbers give us a mixed picture. On the one hand, you end up with a pretty smooth, desirable Qtc of 1.15-a bit higher than the optimal range, but no too bad. On the other hand, your F3 is around 63.
I should point out that most DJ boxes are 3 cubic feet, usually ported, (but so what), and have an F3 around 60 Hz. This is how they make their living, and most people find that to be an aceptable F3, even though you would like something deeper for home listening. If 60 Hz sounded "tinny", DJ's would have to use equipment that goes lower, and they don't. So you can slide by there.
Here is the graph of the Alpha 12:
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Here is the Selenium. It is a somewhat rough through the midrange. The rise in response near 1500 Hz also can be addressed somewhat by an inductor in series. It also will have an F3 in the 60 Hz range. A notch filter around 3500 might not be a bad idea in the crossover-either that or a very steep slope for the crossover.
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Considering that you have only 8 watts to work with, I would say that both of these are workable. Still, you would like to have a slightly deeper response from a large 3.5 cubic foot box, (100 liters). If I were to choose between these two, I think I would lean toward the Eminence because of the smoother midrange response and because it looks like it might be less tricky to cross over.
However, on that tube amp of yours. Does it have a 4 ohm output?
Reason: if you take two 8 ohm speakers and put them in parallel, you will have 6 dB extra output at the same voltage level. However, that voltage level, at 4 ohms, will actually be putting out twice the wattage that it did with an 8 ohm load. The result is, putting two 8 ohm speakers in parallel raises the sensitivity 3 dB.
Since these two PA speakers are about 94 dB through the midrange, what ever their stated sensitivity, that means that if you find an 8 inch speaker or even 6.5 inch speaker with 90 or 91 dB sensitivity through the midrange, hook a pair up in parallel per side, you will have a 93 or 94 dB sensitivity, probaby smoother response, nicer dispersion, and deeper bass in a smaller box.
I have not located these speakers yet, but the numbers seem possible. Do you have a 4 ohm output on the amp? Or a 16 ohm output-that can be configured to raise the sensitivity of two 8 ohm speakers hooked up in series.
Either one-4 ohm or 16 ohm output-would be helpful.
However, on that tube amp of yours. Does it have a 4 ohm output?
Reason: if you take two 8 ohm speakers and put them in parallel, you will have 6 dB extra output at the same voltage level. However, that voltage level, at 4 ohms, will actually be putting out twice the wattage that it did with an 8 ohm load. The result is, putting two 8 ohm speakers in parallel raises the sensitivity 3 dB.
Since these two PA speakers are about 94 dB through the midrange, what ever their stated sensitivity, that means that if you find an 8 inch speaker or even 6.5 inch speaker with 90 or 91 dB sensitivity through the midrange, hook a pair up in parallel per side, you will have a 93 or 94 dB sensitivity, probaby smoother response, nicer dispersion, and deeper bass in a smaller box.
I have not located these speakers yet, but the numbers seem possible. Do you have a 4 ohm output on the amp? Or a 16 ohm output-that can be configured to raise the sensitivity of two 8 ohm speakers hooked up in series.
Either one-4 ohm or 16 ohm output-would be helpful.
Here is a possible alternative I found already. The Audax HP210GO. Have not used it-maybe somebody on this forum has.
It is rated at 92 dB-but the chart seems to show it is really 90 dB. They rate it as 6 ohms-but believe me, with a 5.6 ohm voice coil, it should be called an 8. Most 8's have a 5.6 ohm voice coil. It has a couple of dips in the response, but overall I would rate it around 90 dB. Two of them hooked up in series or parallel will yield an overall response of 93 dB, if you have the proper hookup.
I would put 2 of these into a vented box of 2.5 cu ft tuned to 48 Hz. You should be 3 dB down at 48 or 49 Hz.
They cost $35 each if you buy 4 or more at Parts Express. That's about $70 per side for your woofer, which was about what you were thinking with the PA models.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=296-136
I dont know what the Selenium horn tweeter was going to cost, but a 93 dB tweeter should be available for $20 I would say.
This is just a suggestion. I have not used this driver. There might be others that are better.
It is rated at 92 dB-but the chart seems to show it is really 90 dB. They rate it as 6 ohms-but believe me, with a 5.6 ohm voice coil, it should be called an 8. Most 8's have a 5.6 ohm voice coil. It has a couple of dips in the response, but overall I would rate it around 90 dB. Two of them hooked up in series or parallel will yield an overall response of 93 dB, if you have the proper hookup.
I would put 2 of these into a vented box of 2.5 cu ft tuned to 48 Hz. You should be 3 dB down at 48 or 49 Hz.
They cost $35 each if you buy 4 or more at Parts Express. That's about $70 per side for your woofer, which was about what you were thinking with the PA models.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=296-136
I dont know what the Selenium horn tweeter was going to cost, but a 93 dB tweeter should be available for $20 I would say.
This is just a suggestion. I have not used this driver. There might be others that are better.
Thanks for the help. 🙂
I do have one question, which really doesn't relate to much, but has always made me stop and think... If you take a speaker that has a range from, say, 60-4000Hz, and put it in a ported box of whatever size you have, and it's F3 shows as about 40Hz, is this possible? With its response only going to 60Hz, how can it have an F3 of 40Hz? I just have always wondered...
I do have one question, which really doesn't relate to much, but has always made me stop and think... If you take a speaker that has a range from, say, 60-4000Hz, and put it in a ported box of whatever size you have, and it's F3 shows as about 40Hz, is this possible? With its response only going to 60Hz, how can it have an F3 of 40Hz? I just have always wondered...
Another thought, if I used two 8" PA drivers, each with a said 97dB sens. I would have about 100dB SPL, theoretically. But, if I used this, would having a xover point of 1200Hz be too high?
I was going to edit this by editing, but it has been over 30 min... so....
Ok, if I have the two 8-ohm woofers and an 8-ohm tweeter, the woofers in parallel for 4-ohms, I can't get 8-ohms out of the system. Can I? Need help here also.
Ok, if I have the two 8-ohm woofers and an 8-ohm tweeter, the woofers in parallel for 4-ohms, I can't get 8-ohms out of the system. Can I? Need help here also.
trespasser_guy,
The problem your going to find with 8” woofers and even most 10” woofer is that you won’t be able to find them with enough efficiency for your 8W amp. If you find a 10” that has 90+db/W/m (and there are very few) one unit will cost you at least $100 or more. 12” woofers are easier to find with higher efficiencies, but as with most direct radiators, the wider the bandwidth, the lower the efficiency. That means if you want a lower f3, you have to accept a lower max SPL from the amp/speaker combination. The trade-offs are co$t/lower f3/efficiency. According to Kelticwizard’s graphs, the Eminence appeared to be the best balance of compromises.
You could run the 12” up to 2kHz if you wanted to. I wouldn’t, but if you did, you might think about a 6db/oct cutoff at about 1000Hz for the woofer and a 12db/oct or steeper cutoff at 2000Hz for the Selenium horn. I gave my suggestions in my earlier post, but this would probably work.
If you go with the Eminence woofer and the Selenium horn, I would suggest that you save some room between the woofer and the horn for a future 6 or 8 inch midrange driver. This driver could than be a true midrange driver to run from about 300Hz to 3kHz.
Rodd Yamashita
The problem your going to find with 8” woofers and even most 10” woofer is that you won’t be able to find them with enough efficiency for your 8W amp. If you find a 10” that has 90+db/W/m (and there are very few) one unit will cost you at least $100 or more. 12” woofers are easier to find with higher efficiencies, but as with most direct radiators, the wider the bandwidth, the lower the efficiency. That means if you want a lower f3, you have to accept a lower max SPL from the amp/speaker combination. The trade-offs are co$t/lower f3/efficiency. According to Kelticwizard’s graphs, the Eminence appeared to be the best balance of compromises.
You could run the 12” up to 2kHz if you wanted to. I wouldn’t, but if you did, you might think about a 6db/oct cutoff at about 1000Hz for the woofer and a 12db/oct or steeper cutoff at 2000Hz for the Selenium horn. I gave my suggestions in my earlier post, but this would probably work.
If you go with the Eminence woofer and the Selenium horn, I would suggest that you save some room between the woofer and the horn for a future 6 or 8 inch midrange driver. This driver could than be a true midrange driver to run from about 300Hz to 3kHz.
Rodd Yamashita
Trespasser Guy:
Made a mistake on that F3 for the Eminence. I forgot that when your Qtc is 1 or above, your Fc is at or above the midpoint-not 3 dB down. The actual F3 is probably about 53 Hz for the Eminence, and about the same for the Selenium.
Does your tube amp have a tap in it for 4 ohm or 16 ohm speakers? This could make a big difference.
Roddy: How do you like the idea of hooking two of these Audax HP210GO up in series or parallel? Assuming Trespasser Guy has a 4 or 16 ohm tap, the sensitivity goes up 3 dB. Except for that little dip at 400 Hz it seems to hug the 90 dB line pretty well. I have no idea why they rate this speaker at 92 dB-it clearly is a 90 dB speaker. But two of them hooked up together will play through the midrange at 93 dB. And they are only $140 for four of them.
Made a mistake on that F3 for the Eminence. I forgot that when your Qtc is 1 or above, your Fc is at or above the midpoint-not 3 dB down. The actual F3 is probably about 53 Hz for the Eminence, and about the same for the Selenium.
Does your tube amp have a tap in it for 4 ohm or 16 ohm speakers? This could make a big difference.
Roddy: How do you like the idea of hooking two of these Audax HP210GO up in series or parallel? Assuming Trespasser Guy has a 4 or 16 ohm tap, the sensitivity goes up 3 dB. Except for that little dip at 400 Hz it seems to hug the 90 dB line pretty well. I have no idea why they rate this speaker at 92 dB-it clearly is a 90 dB speaker. But two of them hooked up together will play through the midrange at 93 dB. And they are only $140 for four of them.
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Kelticwizard,kelticwizard said:
It’s not a bad idea at all. 2 drivers in // and in an MTM arrangement should have enough efficiency for an 8W amp (besides, tp_g could build a 20W gainclone later for <$50). If tp_g goes that route, I would suggest losing the horn (as I live and breath) for more dome tweeter. I’m thinking something like BrianGT’s Thor arrangement (I know it’s not Brian’s, I just think of him when I think of the Thor). Here’s the link to his project. The design is the same with phrugal parts.
http://www.diyaudio.com/forums/show...=15&highlight=thor finish router&pagenumber=1
Of course, trespasser_guy, you know you would have to get used to the idea of the tower type enclosure. From the VOT to the Thor in one thread,... it's like Back to the Future.😀
Rodd Yamashita
A Transmission Line is surely an option. Whenever you mention two woofers, some kind of tower comes to mind. And towers are attractive to look at.
Meanwhile, if there is anyone out there who knowws of cheaper priced 6 1/2 " or 8" woofers that play in the 92 dB range, please let us know.
The HP210GO's were just a quick example.
There are plenty of speakers rated at 92 dB. but if Trespasser guy can actually find one that plays smoothly through the midrange at 92 dB, then two of them will give him 95 dB which will be quite an accomplishment, I think.
Meanwhile, if there is anyone out there who knowws of cheaper priced 6 1/2 " or 8" woofers that play in the 92 dB range, please let us know.
The HP210GO's were just a quick example.
There are plenty of speakers rated at 92 dB. but if Trespasser guy can actually find one that plays smoothly through the midrange at 92 dB, then two of them will give him 95 dB which will be quite an accomplishment, I think.
Here is something interesting. With the 8 watt requirement, you don't need that much air moving capability. Try this Eminence-the Beta *. It would seem to fit into a 1.25 cubic ft box, where it would have an F3 of 58 or so. It is wickedly sensitive-like 97 dB- and relatively smooth throughout it's midrange.
Parts Express sells it for something under $73. It would be nice to buy two per side, but one is pretty good.
I would surely take this over either 12".
Parts Express sells it for something under $73. It would be nice to buy two per side, but one is pretty good.
I would surely take this over either 12".
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Take a look at some of the Seas woofers from Madisound. Also Speakerworks has a smaller Seas selection, but at a better price. The 8" woofers are running in the $50 - $60 range with sensitivities in the 88 to 92 range with low f3's.
Rodd Yamashita
Rodd Yamashita
Oops-typo. I am beyond the half an hour limit. That is the Eminence Beta 8 I was speaking about above.
It is part # 290-404 at Parts Express:
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=290-404&DID=7
It is part # 290-404 at Parts Express:
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=290-404&DID=7
I once used a JBL 2206 for a two-way speaker (together with the horn from the 2230 monitor) and that one sounded very nice.
I have to admit that of course everything sounds nice I have built so far and that I never have made proper measurements on that one. 😉 😉
According to the datasheet the driver boasts 95 dB/1W efficiency and it is very well behaved up to ca 2 kHz.
With an fs of 50 Hz and Qts of 0.34 it wouldn't go very low with a classic B4 alignment. But tha low VAS value of 60liters only would allow low tunings with reasonably sized boxes.
It has even some hithech appeal with it's paper/glassfibre composite cone.
Regards
Charles
I have to admit that of course everything sounds nice I have built so far and that I never have made proper measurements on that one. 😉 😉
According to the datasheet the driver boasts 95 dB/1W efficiency and it is very well behaved up to ca 2 kHz.
With an fs of 50 Hz and Qts of 0.34 it wouldn't go very low with a classic B4 alignment. But tha low VAS value of 60liters only would allow low tunings with reasonably sized boxes.
It has even some hithech appeal with it's paper/glassfibre composite cone.
Regards
Charles
I also found this Eminence, the Alpha-8A. I am not sure where you are finding these graphs, but, there is one in the pdf ( http://www.partsexpress.com/pdf/290-401.pdf ) and it seems to be similar to the Beta. It also has 97dB sensitivity. I am not sure of the differences here...
But, if I used two of either of these, with 97dB efficiency each, and linked them in parallel, I would have 100dB? Correct? Then how would I add in a tweeter with 8-ohm impedence? Wouldn't I get something strange like 6-ohms overall?
Oh, kelticwizard, you have asked me a couple of times, but I haven't replied- sorry. I am not sure if the amp will have 4 or 16-ohm taps. I was thinking about going with the S-5 kit, but may find an older amp on eBay that either works or needs a bit of repairs. Then I can learn a thing or two about tubes as well. So it is looking like it will be low powered, though, either way- less than 10 watts, probably.
But, if I used two of either of these, with 97dB efficiency each, and linked them in parallel, I would have 100dB? Correct? Then how would I add in a tweeter with 8-ohm impedence? Wouldn't I get something strange like 6-ohms overall?
Oh, kelticwizard, you have asked me a couple of times, but I haven't replied- sorry. I am not sure if the amp will have 4 or 16-ohm taps. I was thinking about going with the S-5 kit, but may find an older amp on eBay that either works or needs a bit of repairs. Then I can learn a thing or two about tubes as well. So it is looking like it will be low powered, though, either way- less than 10 watts, probably.
Hmmm, I just tried to edit and it wouldn't let me.... 
I was going to ask what a good crossover point would be... The only other really affordable tweeter I could find, horn wise, that is, was the selenium D205TI, which goes down to 800Hz, but is recommended to cross over at 1200. It only goes up to 18KHz, though, but from what I have heard most cannot hear that anyway. It is here: http://www.partsexpress.com/pe/show...46&St3=31864414&DS_ID=3&Product_ID=6315&DID=7
The other one around the $50 mark is this one: http://www.partsexpress.com/pe/show...46&St3=31864414&DS_ID=3&Product_ID=5603&DID=7 . It does go down to 600Hz, but I don't know how good it would be- I have heard a lot about Selenium, and do somewhat trust their products, but don't know anything about these drivers. I do like the look of a horn tweeter, and that is what my design is based around, for the most part.
I was going to ask what a good crossover point would be... The only other really affordable tweeter I could find, horn wise, that is, was the selenium D205TI, which goes down to 800Hz, but is recommended to cross over at 1200. It only goes up to 18KHz, though, but from what I have heard most cannot hear that anyway. It is here: http://www.partsexpress.com/pe/show...46&St3=31864414&DS_ID=3&Product_ID=6315&DID=7
The other one around the $50 mark is this one: http://www.partsexpress.com/pe/show...46&St3=31864414&DS_ID=3&Product_ID=5603&DID=7 . It does go down to 600Hz, but I don't know how good it would be- I have heard a lot about Selenium, and do somewhat trust their products, but don't know anything about these drivers. I do like the look of a horn tweeter, and that is what my design is based around, for the most part.
tp_g,
If you have decided to go with the dual 8”, than your x-over point can raise as high as 3kHz. Although you should probably x-over in the 2kHz to 2.5kHz range. This also gives you more choices for tweeters. This one horn tweeter caught my eye:
http://www.partsexpress.com/pe/show...6&St3=31864414&DS_ID=3&Product_ID=16171&DID=7
Right in your price range.
Rodd Yamashita
If you have decided to go with the dual 8”, than your x-over point can raise as high as 3kHz. Although you should probably x-over in the 2kHz to 2.5kHz range. This also gives you more choices for tweeters. This one horn tweeter caught my eye:
http://www.partsexpress.com/pe/show...6&St3=31864414&DS_ID=3&Product_ID=16171&DID=7
Right in your price range.
Rodd Yamashita
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