For those new to DIY loudspeakers, two rules apply; KISS & The 7 Ps - Keep it simple, stupid, and Prior planning and preparation prevents p*ss poor performance.
Would you, on going somewhere new, wait until you are lost before consulting a map? Most wives would answer "Yes" to this question as it is a well known fact that men hate to ask directions. If you know exactly how you intend to get to your destination every step falls into place. Though I know this, I am still prone to vacillation and ****-ups, most people are bad at following their own advice.
I suppose what I'm saying is, don't try to build an LS3/5A and its crossover until you have built something simpler and worked out what affects what.
In 1974 I thought to buy some speakers, and standing in tho shop, listening to a pair of Gale 401s, I realised I was listening to all the sympathetic resonances fromthe other 20 odd pairs in the shop, so I decided to make my own and tailor them to my room.
I started with T27/B110 and the KEF crossover and built a very rigid and heavy, BBC sized cabinet using blockboard; which, as a layer of different blocks of endgrain wood sandwiched between two layers of 3ply is very stiff and totally non-resonant; I could hear little difference between them and my neighbours LS3/5As. I sold them to a friend after a year or so, and they now reside in Vancouver, as he hasn't made a warranty claim, I assume they still work!
Next a pair of stand mounted reflex cabinets using a modified KEF crossover, T27/B200s and an STC2001Gs; a supertweeter, like the things the HiFi world has just discovered, you know, the afterthoughts they mount on top firing at the edge of the cabinet, generating diffraction artifacts! These also were sold and have been from London to Florida, Carolina, New York, France and back to London; and after 30 years are still in daily use.
My last pair, in about 1980, were a version of the previous ones, but in a pyramid shaped cabinet, I had reasoned that whatever lenght ratios a rectangular box had, somehow standing waves would be generated, hence sloping sides, these I still use after 25 or more years. I played around with the port till I got it to sound right in my living room, then I left them alone. Now I worry in case they break, I have bought spare T27s and B200s through ebay and am keeping my eyes peeled for STC2001Gs and crossover boards.
Moral - you can make the difference, because you can lavish more time and enthusiasm on the parts you control than a manufacturer ever could, for you experimentation is inexpensive, the wood/MDF/Ply or whatever is relatively cheap compared with the drivers; the labour a zero cost component. Just use good quality parts, and they'll last you a lifetime. Remember,you are not re-inventing the wheel, just redesigning the tyres that fit them.
Now I've got the itch to build again, infectious this forum!
Would you, on going somewhere new, wait until you are lost before consulting a map? Most wives would answer "Yes" to this question as it is a well known fact that men hate to ask directions. If you know exactly how you intend to get to your destination every step falls into place. Though I know this, I am still prone to vacillation and ****-ups, most people are bad at following their own advice.
I suppose what I'm saying is, don't try to build an LS3/5A and its crossover until you have built something simpler and worked out what affects what.
In 1974 I thought to buy some speakers, and standing in tho shop, listening to a pair of Gale 401s, I realised I was listening to all the sympathetic resonances fromthe other 20 odd pairs in the shop, so I decided to make my own and tailor them to my room.
I started with T27/B110 and the KEF crossover and built a very rigid and heavy, BBC sized cabinet using blockboard; which, as a layer of different blocks of endgrain wood sandwiched between two layers of 3ply is very stiff and totally non-resonant; I could hear little difference between them and my neighbours LS3/5As. I sold them to a friend after a year or so, and they now reside in Vancouver, as he hasn't made a warranty claim, I assume they still work!
Next a pair of stand mounted reflex cabinets using a modified KEF crossover, T27/B200s and an STC2001Gs; a supertweeter, like the things the HiFi world has just discovered, you know, the afterthoughts they mount on top firing at the edge of the cabinet, generating diffraction artifacts! These also were sold and have been from London to Florida, Carolina, New York, France and back to London; and after 30 years are still in daily use.
My last pair, in about 1980, were a version of the previous ones, but in a pyramid shaped cabinet, I had reasoned that whatever lenght ratios a rectangular box had, somehow standing waves would be generated, hence sloping sides, these I still use after 25 or more years. I played around with the port till I got it to sound right in my living room, then I left them alone. Now I worry in case they break, I have bought spare T27s and B200s through ebay and am keeping my eyes peeled for STC2001Gs and crossover boards.
Moral - you can make the difference, because you can lavish more time and enthusiasm on the parts you control than a manufacturer ever could, for you experimentation is inexpensive, the wood/MDF/Ply or whatever is relatively cheap compared with the drivers; the labour a zero cost component. Just use good quality parts, and they'll last you a lifetime. Remember,you are not re-inventing the wheel, just redesigning the tyres that fit them.
Now I've got the itch to build again, infectious this forum!
rabbitz said:
Rabbitz,
I've tried to look at the 850122 driver. When I look at the data sheet, it seems to have a sensitivity rise over 2kHz, and if any higher output is needed, I would think it's low for the tweeter to XO there???
I still kind of like the HDS 164 judging by the specs, but then again I haven't seen the price tag of the 850122 driver (can't find it in the stores near me).
Is there a huge difference, or is there a hidden advantage with the 850122 that I've missed?
Jennice
Riku-78
You're right about centre speakers requiring shielding (mine are) if they are near a CRT but I was only talking about a stereo pair. I just wanted to say it's not a problem with stereo speakers so it gives you a larger choice of drivers.
Jennice
I think the response graph is a bit misleading and does not translate into the real world IMO. I think it's more beneficial to look at the off axis response or somewhere in between as that's where the listening is done. I've got mine crossed over just under 3000Hz (after plenty of testing various xo frequencies) with a 1st order series xo and no problems at all.
There was some discussion a while ago on the 850122 and it was thought that the Data Sheet was out of date and should be similar to the HDS driver but data sheets are only a guide anyway and you can't choose a driver only using this information as it gives no indication on how it sounds. That's where this forum is great as you do get to find what's good or not, what's hot, what's good value etc.
I haven't heard a bad report on the Peerless CSX 850122 (doesn't mean that there isn't any) and the DIYers that I know who have used it and from posts I've read are extremely happy. I believe it's essentially the same driver as the HDS 850439 except for steel pressed basket instead of the HDS cast aluminium basket. There has been posts that some prefer the CSX to the HDS and probably the other way around as well. Both drivers are great value IMHO and I'll stick by my comment that the 850122 is a very nice driver, well behaved and easy to work with when doing crossovers (sounds great too BTW).
I don't know if Michael is still hanging around this forum (care to comment Michael) but he left a review on the 850122 at a supplier's site.
http://www.advanceae.com.au/catalog/product_reviews_info.php?products_id=2460&reviews_id=11
Nuff said.
You're right about centre speakers requiring shielding (mine are) if they are near a CRT but I was only talking about a stereo pair. I just wanted to say it's not a problem with stereo speakers so it gives you a larger choice of drivers.
Jennice
I think the response graph is a bit misleading and does not translate into the real world IMO. I think it's more beneficial to look at the off axis response or somewhere in between as that's where the listening is done. I've got mine crossed over just under 3000Hz (after plenty of testing various xo frequencies) with a 1st order series xo and no problems at all.
There was some discussion a while ago on the 850122 and it was thought that the Data Sheet was out of date and should be similar to the HDS driver but data sheets are only a guide anyway and you can't choose a driver only using this information as it gives no indication on how it sounds. That's where this forum is great as you do get to find what's good or not, what's hot, what's good value etc.
I haven't heard a bad report on the Peerless CSX 850122 (doesn't mean that there isn't any) and the DIYers that I know who have used it and from posts I've read are extremely happy. I believe it's essentially the same driver as the HDS 850439 except for steel pressed basket instead of the HDS cast aluminium basket. There has been posts that some prefer the CSX to the HDS and probably the other way around as well. Both drivers are great value IMHO and I'll stick by my comment that the 850122 is a very nice driver, well behaved and easy to work with when doing crossovers (sounds great too BTW).
I don't know if Michael is still hanging around this forum (care to comment Michael) but he left a review on the 850122 at a supplier's site.
http://www.advanceae.com.au/catalog/product_reviews_info.php?products_id=2460&reviews_id=11
Nuff said.
I tried to read the entire thread again. Hope I'm not repeating anything. But I've watched this thread with acute interest. I'm one of those beginners who's looking for the right project to jump in with. I really liked the Hatt MkIII but am still just a little shy about the metal drivers and the lack of really widespread experience and comment about them on the web. I began to like what I read about the Peerless 850488 and recently found a plan at
http://home.wanadoo.nl/dezaire/My own system.htm
This is it! I thought. Really loved the drivers and the cabinet design and the look of the crossover and.... I went to price the drivers. Over three hundred dollars already for the tweeters alone. Damn!!! Looking a little further, I found this.
http://home1.stofanet.dk/troels.gravesen/index_b/HDS134_DX25TG.htm
Tell me - is there any reason why this should not top the list for a great little reference speaker in this thread for the beginner? I know I shouldn't ask. If I get talked out of one more design at this point I don't know what I'll do. Get up some drunk courage and just brandish my credit card?
http://home.wanadoo.nl/dezaire/My own system.htm
This is it! I thought. Really loved the drivers and the cabinet design and the look of the crossover and.... I went to price the drivers. Over three hundred dollars already for the tweeters alone. Damn!!! Looking a little further, I found this.
http://home1.stofanet.dk/troels.gravesen/index_b/HDS134_DX25TG.htm
Tell me - is there any reason why this should not top the list for a great little reference speaker in this thread for the beginner? I know I shouldn't ask. If I get talked out of one more design at this point I don't know what I'll do. Get up some drunk courage and just brandish my credit card?
bluebeard said:
XO is much more complex than i like to see, as well my opion of that peerless is coloured by friends experience with the phase plug version -- he hasn't managed to get them to sound as good as his P13 dalines (these were one of the reference projects for this thread)
Daline Note: the Linn ceramic T was replaced with (a modified) Vifa tweeter & XO from this ref project (this change predates this thread)
dave
planet10 said:
would the Daline design offer bass extension benefits over a vented small enclosure (okara, with 5uF cap), i ask only that i built a small enclosure for these and they really did seem base shy but very musical.
Could i also subtitute the tweeter with a SS 9500?
I originally planned on doing an Okara but could find no crossover designs...I am hoping the Daline TL may hold the answer for me...(love the p13 sound but really needs more bass for my taste)
Dave,
Thanks for the feedback,
I am sure the Vifa tweeters are superb performers. I was however, looking to use drivers i already had at my disposal which I did not make clear in my original post, any ideas?
Perhaps the answer for me is to optimize for the p13 and look elsewhere to provide the "feel"
I guess I am at risk of moving the direction of the thread away from the core subject, and am offering up another alternative to an already option rich thread, thereby diluting it further.
But, i am still keen to utilise my drivers, how easy would it be for me to utilise the SS tweeter option as a substitution in the finalised design if i keep it quiet
mark
Thanks for the feedback,
I am sure the Vifa tweeters are superb performers. I was however, looking to use drivers i already had at my disposal which I did not make clear in my original post, any ideas?
Perhaps the answer for me is to optimize for the p13 and look elsewhere to provide the "feel"
I guess I am at risk of moving the direction of the thread away from the core subject, and am offering up another alternative to an already option rich thread, thereby diluting it further.
But, i am still keen to utilise my drivers, how easy would it be for me to utilise the SS tweeter option as a substitution in the finalised design if i keep it quiet
mark
Hello,
Nice topic this is/was...
I have build this design using the Vifa P13WH-00 and Vifa HT-275D2 tweeter:
http://img511.imageshack.us/img511/9756/p8130040go0.jpg
http://img53.imageshack.us/img53/5516/p8130041km4.jpg
http://img423.imageshack.us/img423/5953/p50600249lm.jpg (using the single cap)
http://img65.imageshack.us/img65/1059/p50700264yu.jpg
First I tried the 5uF cap (in this case a very good 800V Audyn Plus 4.7uF) and really this sounds good. But after seeing this threat I now have tried the series crossover, and I have to agree it sounds even better! Doing some measurement with my RTA it turned out the polarity on the tweeter had to be reversed using the series crossover. I did not read this in this topic so this might be a usefull tip. Polarity really did make a big difference. With the wrong polarity I got a wide 6dB dip around the 3kHz crossover frequency.
I am going to listen to this crossover for some time. If I really like it I will buy some of the very best components to build it. (only the components for each cabinet so costs are not that high). But even know I have used a MOX resistor, MKP cap and 1.4mm wire aircore coil.
Best regards,
Walt
Nice topic this is/was...
I have build this design using the Vifa P13WH-00 and Vifa HT-275D2 tweeter:
http://img511.imageshack.us/img511/9756/p8130040go0.jpg
http://img53.imageshack.us/img53/5516/p8130041km4.jpg
http://img423.imageshack.us/img423/5953/p50600249lm.jpg (using the single cap)
http://img65.imageshack.us/img65/1059/p50700264yu.jpg
First I tried the 5uF cap (in this case a very good 800V Audyn Plus 4.7uF) and really this sounds good. But after seeing this threat I now have tried the series crossover, and I have to agree it sounds even better! Doing some measurement with my RTA it turned out the polarity on the tweeter had to be reversed using the series crossover. I did not read this in this topic so this might be a usefull tip. Polarity really did make a big difference. With the wrong polarity I got a wide 6dB dip around the 3kHz crossover frequency.
I am going to listen to this crossover for some time. If I really like it I will buy some of the very best components to build it. (only the components for each cabinet so costs are not that high). But even know I have used a MOX resistor, MKP cap and 1.4mm wire aircore coil.
Best regards,
Walt
There are a few variations of the standard series crossover values you can try for the D27TG-45-06 / P13WH-00-08 combo.
For one with more BSC and a lower top end with an exagerated BBC dip:
R1=10R, L1=0.7mH, C1=3.3uF, -ve tweeter polarity, 7ohm min.
For a flatter one with some BSC and a tad of BBC dip:
R1=6R8, L1=0.7mH, 3.3uF, -ve tweeter polarity, 7 ohm min. This one is closest to the AR series crossover and a good alternative if component costs need to be kept low.
For a flat response without BSC:
R1=4R7, L1=0.47mH, C1=6.8uF, +ve tweeter polarity, 7 ohm min with the smoothest impedance curve of the standard series crossovers.
See the drawing for designations and the tweeter polarity as drawn is +ve, so reverse for -ve polarity.
For one with more BSC and a lower top end with an exagerated BBC dip:
R1=10R, L1=0.7mH, C1=3.3uF, -ve tweeter polarity, 7ohm min.
For a flatter one with some BSC and a tad of BBC dip:
R1=6R8, L1=0.7mH, 3.3uF, -ve tweeter polarity, 7 ohm min. This one is closest to the AR series crossover and a good alternative if component costs need to be kept low.
For a flat response without BSC:
R1=4R7, L1=0.47mH, C1=6.8uF, +ve tweeter polarity, 7 ohm min with the smoothest impedance curve of the standard series crossovers.
See the drawing for designations and the tweeter polarity as drawn is +ve, so reverse for -ve polarity.
Attachments
For an AR series crossover which has the flattest response, best driver behaviour, best tweeter protection and BSC:
C1=22uF, L2=1.2mH, R1=6R8, L1=0.11mH, -ve tweeter polarity, 7 ohm min impedance and the smoothest impedance curve.
As above the drawing shows +ve tweeter polarity and reverse for -ve polarity.
As with all series crossovers, use an inductor with the lowest DCR that you can afford.... less than 5% of the woofer's Re.
C1=22uF, L2=1.2mH, R1=6R8, L1=0.11mH, -ve tweeter polarity, 7 ohm min impedance and the smoothest impedance curve.
As above the drawing shows +ve tweeter polarity and reverse for -ve polarity.
As with all series crossovers, use an inductor with the lowest DCR that you can afford.... less than 5% of the woofer's Re.
