Need help with cheap crossovers

[XtremeRevolution]

Alright, so I built your crossover with the two coils. I had bought 4 of the peerless india buyout 3" drivers and I can honestly say I greatly dislike them. I don't like the way they look, I don't like the way they sound, and I don't like how easily they distort and how little bass output they have.

By comparison, the Aura NS35's which are cheaper and .5 inches larger are a MUCH better driver, which is great because I bought 12 of them and will likely buy another 12 of them this week.

I'm going to start selling these speakers on a website a buddy of mine is designing for me, so whatever profit I make, I'll share with you since you helped me with the crossover. Simply put, these sound amazing.

http://techtalk.parts-express.com/sh...17#post1727717

[Chris Roemer]

if they start selling, i think you owe me a cut....

i tried several versions with and without the coil in the tweeter circuit. leaving it out helped with phase alignment, but increased distortion, made FR a little worse and tended to droop faster off-axis, and while overall they sounded similar, it wasn't quite as good. i'm still not 100% thrilled with the more complex crossover, but i think it's better.

in the comparison charts between the two, the simpler one is green, the one with the coil in the high pass is yellow. the first one is just different values of the series cap and how it affects FR. I wasn't that careful about the off-axis, but it's about 25-30°. the measurements were done in-room quickly, so there's some artifacts in there, but they're the same for all of them.

Maybe I don't understand your graphs, but it LOOKS like you're summing out of phase to get a flatter response. Your individual driver response curves are higher than your sum (in the overlap region). What's up?

Chris

[patrickm]

Maybe I don't understand your graphs, but it LOOKS like you're summing out of phase to get a flatter response. Your individual driver response curves are higher than your sum (in the overlap region). What's up?

Chris

he asked for an update of where the design was (still in the middle of testing), and wanted quick and cheap... (i saw in another thread he actually fired up a test pair today for a party). i'm actually still not done, but yes, the second version does start to wander phase-wise, and i thought i noted that in the post. there are also FR plots for both versions in there... the black line in each graph is the summed response and red/blue are the individual drivers. the yellow and green are comparisons.

the first one's phase is pretty close, but it does distort at lower power b/c it's only a 1st order electrical on the cheap tweeter. this is still in progress, but is getting better. haven't built this one yet, but the slopes are steeper and the phase tracking is better, (but it uses more parts than he wanted). but i was going to wait until i got further until i put up another update.

i was actually surprised that he thought the drivers sounded bad -- i haven't heard the aurasounds (and would certainly believe they produce better bass) but the peerless india's seemed pretty well built and fairly smooth. may just be a matter of taste, too, because i doubt the phase lines up appreciably better with the aurasounds than the peerless.

[XtremeRevolution]

he asked for an update of where the design was (still in the middle of testing), and wanted quick and cheap... (i saw in another thread he actually fired up a test pair today for a party). i'm actually still not done, but yes, the second version does start to wander phase-wise, and i thought i noted that in the post. there are also FR plots for both versions in there... the black line in each graph is the summed response and red/blue are the individual drivers. the yellow and green are comparisons.

the first one's phase is pretty close, but it does distort at lower power b/c it's only a 1st order electrical on the cheap tweeter. this is still in progress, but is getting better. haven't built this one yet, but the slopes are steeper and the phase tracking is better, (but it uses more parts than he wanted). but i was going to wait until i got further until i put up another update.

i was actually surprised that he thought the drivers sounded bad -- i haven't heard the aurasounds (and would certainly believe they produce better bass) but the peerless india's seemed pretty well built and fairly smooth. may just be a matter of taste, too, because i doubt the phase lines up appreciably better with the aurasounds than the peerless.

Yeah the Aura NS35's do sound a lot better. I mounted them to a baffle real quick just for a quick listen and they do sound a lot better. One thing that bothers me is that my Lepai amp shuts down very, very quickly with just one Peerless India driver under any volume, while I can run the NS35's as loud as the amp will go without it shutting down. Considering I'm giving these to my mom as a gift, I think that was a bit important.

Honestly, these sound amazing. Short of a lack of deeper bass (what do you expect from a 3.5" $4.50 driver with a low xmax) they do sound very, very good, especially with a sub.

Yes, I did play them for a party. They were sitting on the edge of a trampoline ~15 feet away from the party and everyone loved them. They sound very clear, very large, and have a very wide sound stage.

I'm content with this crossover. $37 for all of the parts not including terminals is pretty darn good and they don't fail to impress. The bass is actually quite adequate for outdoor party use surprisingly. I'd say they're solid down to 90hz in the .1 cubic foot sealed boxes I made for them.

[patrickm]

Yeah the Aura NS35's do sound a lot better. I mounted them to a baffle real quick just for a quick listen and they do sound a lot better. One thing that bothers me is that my Lepai amp shuts down very, very quickly with just one Peerless India driver under any volume, while I can run the NS35's as loud as the amp will go without it shutting down. Considering I'm giving these to my mom as a gift, I think that was a bit important.

that doesn't sound good. i wonder if those drivers are bad. i ran 3 of mine off a lepai amp to break them in for about 8 hours without any issues. do you have any way of measuring their impedance? (i guess even a dc resistance from a voltmeter would work as an initial cut). i've also been running the testing off an old pioneer HT receiver, without any problems, and i traced actual impedance curves that shouldn't hurt a lepai.

btw, if you need cheap party speakers, check out the bravox budget tower in my signature -- PE just added some price breaks, so if you go for 4, it's almost as cheap as the nuance-peerless/aura for the drivers, with woofers $7 and tweeters $5. i have them in the full tower (1.4 cu ft, 8.5 x 12 x 36) right now, and they play down to about 35-45 hz in-room. once i get some time (probably mid-may), i'm going to try a sealed and vented bookshelf version, where they're about 11.5" tall. almost ready to call that design finished and put it up in the gallery, but i want to try them in some other room configurations to make sure they're not just a good fit in my particular HT room.

glad the quick crossover worked, though.

[XtremeRevolution]

that doesn't sound good. i wonder if those drivers are bad. i ran 3 of mine off a lepai amp to break them in for about 8 hours without any issues. do you have any way of measuring their impedance? (i guess even a dc resistance from a voltmeter would work as an initial cut).

btw, if you need cheap party speakers, check out the bravox budget tower in my signature -- PE just added some price breaks, so if you go for 4, it's almost as cheap as the nuance-peerless/aura for the drivers, with woofers $7 and tweeters $5. i have them in the full tower (1.4 cu ft, 8.5 x 12 x 36) right now, and they play down to about 35-45 hz in-room. once i get some time (probably mid-may), i'm going to try a sealed and vented bookshelf version, where they're about 11.5" tall. almost ready to call that design finished and put it up in the gallery, but i want to try them in some other room configurations to make sure they're not just a good fit in my particular HT room.

glad the quick crossover worked, though.

Not sure if I have an issue with the Lepai amp and needing a bigger power supply like others have. I tested two of those drivers. Just hooked them up directly to the amp. Same problem with both. I might throw them in my mini cubes in place of the ND65's just to see how they do in a box.

Whatever, I'm happy. I'd even rather sell the Peerless drivers and keep building these; they sound great! I do have a multimeter that I can use, so I'll check those out some time this week if I can remember to.

1.4 cubic feet is way way way too large. I wanted something stupid cheap and very "cute." This was was precisely what I was looking for and you helped make it a success. I would love to bring a pair of these to the next regional meet we have since I'll definitely be making more of these.

[2leftthumbs]

If the aura 3.5" shares much with its 6" brother it has a pretty good top end and may not need a tweeter for your purposes.

[XtremeRevolution]

If the aura 3.5" shares much with its 6" brother it has a pretty good top end and may not need a tweeter for your purposes.

I tried it without a tweeter and while it sounded ok, it sounds much better with the tweeter. There was a tinny sound to it without the tweeter.

I tested one of the Peerless India 3" drivers yesterday, and it read ~3.6ohms impedance.

[patrickm]

crossover is corrected in the earlier post. still haven't had time to tweak/optimize to the point where I'd call it 'final', but it fixes the phase problem and sounds decent.

also, when building my second test box for these earlier, I remembered that the peerless woofer doesn't have a lot of breathing room behind the cone. i'd highly recommended hacking away some of the material behind and either chamfer or roundover until about 1/4" is left full-thickness. this might account for some of the distortion you had at low volumes. i'm just testing it out before i measured, and i got a pretty decent volume level out of it before distortion really set in (though with an old HT receiver, not a lepai). mine measured about 3.4 ohms with a voltmeter, and a little less at low frequencies on the WT3, so yours may not have any problems (unless there's a cone sag issue, like some of the blue cone bravox woofers from that same factory buyout). an 80-100hz high pass also makes a world of difference.

[XtremeRevolution]

crossover is corrected in the earlier post. still haven't had time to tweak/optimize to the point where I'd call it 'final', but it fixes the phase problem and sounds decent.

also, when building my second test box for these earlier, I remembered that the peerless woofer doesn't have a lot of breathing room behind the cone. i'd highly recommended hacking away some of the material behind and either chamfer or roundover until about 1/4" is left full-thickness. this might account for some of the distortion you had at low volumes. i'm just testing it out before i measured, and i got a pretty decent volume level out of it before distortion really set in (though with an old HT receiver, not a lepai). mine measured about 3.4 ohms with a voltmeter, and a little less at low frequencies on the WT3, so yours may not have any problems (unless there's a cone sag issue, like some of the blue cone bravox woofers from that same factory buyout). an 80-100hz high pass also makes a world of difference.

Sounds great. I still need to send you a NS35 or two next month to have you test those and see if any modifications would need to be done to the crossover. Not sure if I'll get any more of these built till then, since I have to build a 15" home theater sub, Overnight Sensations MTMs, a pair of NS6/Vifa TM's, and my own personal Statement Monitors.

BTW, the peerless started distorting open air. I didn't even have it on a baffle. In any case, I'm quite happy with the NS35's. I also noticed they have a stiffer suspension.

[XtremeRevolution]

I finally built a set of these with Patrick's new revised crossover. The other one only went up to 11.1 uf on the capacitors as I had to run a ton of them in parallel and had strange combination of resistors, but these were built to spec. Patrick, these sound amazing. Check my thread for more impressions. I think I'll be making a writeup soon unless you have any other advise.

Oh, and I didn't have to buy any coils! I discovered that my WT3 allows me to measure inductance, so I unwound one of the coils that I would otherwise not be using to the exact specification I needed. I was pretty happy I was able to do that and not spend $10 on another pair of coils.

[patrickm]

hey - glad to hear this was a success.

also, fwiw, since i know you had some drivers laying around, i did finish up the project using the peerless india woofers - not junk by any stretch, just need some care during mounting (basically cutting back the baffle to about 1/4" so it can breathe), and they do pretty well in a very small vented box (5x8x5.5"). i'm sure they'd do better in a slightly larger one than i used, but the recipient of these was very happy with them, they met the criteria for tiny-ness, and i was impressed by the overall quality of a 5-speaker set built for $110 including wood & stain (arsenal of expensive tools not included). i did go with the 2nd order electrical on the tweeter with those.

[XtremeRevolution]

Patrick, did you have a .frd file for that tweeter?