Members moody Posted January 29, 2008 Members Share Posted January 29, 2008 In my thread the other day I asked about whether I should replace diaphragms on a couple of celestion horns I have. Having asked and gotten a couple of responses, I decided to try to get hold of the replacements and fix them. So presuming the people that I emailed ever answer that problem should be out of the way. However, while trying to decide I looked at what was available and I confess that I am really, really confused (and presume there are others that may also be confused). I don't need anything at the moment but I am trying to figure out from the minefield of options available what is good, what is bad and what is right for different applications. For example, I know that in general piezo's are cheap and sound pretty awful, I know that compression drivers of various bolt on and screw on varieties are generally pretty decent (I'm sure with exceptions). What I don't understand is those that fall in the in-between categories. There are a whole range of bullet tweeters, bullet horns, super tweeters and other non-piezo yet generally usually cheap options that I am wondering about? What is there purpose? Are they bottom feeder options or a viable alternative? Are there hidden gems in this minefield or should they be steered clear off? I know this is a really open question, but I'm sure I will eventually want to make or modify some speaker cabinet or other and would like to know what the options are out there. Link to comment Share on other sites More sharing options...
Members Harmonycat Posted January 29, 2008 Members Share Posted January 29, 2008 The hidden Gem in the "beamy bunch" are the RTT-50. They have a horn flare and as such are not as beamy in their dispersion characteristics. Traditional bullets and such provide a very narrow dispersion pattern and thus sound as if they have little high end in an off axis position. They work in a stage monitor but that is about it. The other problem is that you have to cross them at about 3Khz plus as opposed to say 1.8K plus, in 1" diaphram compression drivers. This limits their use in many cases to a maximum size 12" woofer in most cases. The old EV 15" with the 2.5" voicecoils were one of the few exceptions. 3Khz is along way up for many 15" woofers to still reproduce a linear response. The diaphrams were usually phenolic and some brands had brutal strident sounding frequency responses. Celestions were very smooth. Almost High Fidelity sounding back then. They still sound good today! In the old days, (early 80's), they provided a solution to a diaphram compression driver and horn that invariably were pricey. The least expensive readily available in the day were the Peavey 22 series stuff. JBL 2425 drivers and such were really pricey. I used to buy used "Potato Masher JBLs" relativelycheap. Today there is a myriad of inexpensive options in compression driver and flare combinations. The Selenium stuff is really very good at Parts Express and offer fabulous bang for the buck! I started using them back in the early 90's. Link to comment Share on other sites More sharing options...
Members preacherman672 Posted January 29, 2008 Members Share Posted January 29, 2008 Piezos will work and sound really good if you use them in a vertical array. If you use them in a cut and glued crossfired array you can get useful response down to 2k. The trade off is vertical dispersion which is not that critical IMO in most situations. Les Link to comment Share on other sites More sharing options...
Members tlbonehead Posted January 30, 2008 Members Share Posted January 30, 2008 The hidden Gem in the "beamy bunch" are the RTT-50. They have a horn flare and as such are not as beamy in their dispersion characteristics. Traditional bullets and such provide a very narrow dispersion pattern and thus sound as if they have little high end in an off axis position. They work in a stage monitor but that is about it. The other problem is that you have to cross them at about 3Khz plus as opposed to say 1.8K plus, in 1" diaphram compression drivers. This limits their use in many cases to a maximum size 12" woofer in most cases. The old EV 15" with the 2.5" voicecoils were one of the few exceptions. 3Khz is along way up for many 15" woofers to still reproduce a linear response. The diaphrams were usually phenolic and some brands had brutal strident sounding frequency responses. Celestions were very smooth. Almost High Fidelity sounding back then. They still sound good today! In the old days, (early 80's), they provided a solution to a diaphram compression driver and horn that invariably were pricey. The least expensive readily available in the day were the Peavey 22 series stuff. JBL 2425 drivers and such were really pricey. I used to buy used "Potato Masher JBLs" relativelycheap. Today there is a myriad of inexpensive options in compression driver and flare combinations. The Selenium stuff is really very good at Parts Express and offer fabulous bang for the buck! I started using them back in the early 90's. The DT205TI is probably my favorite budget driver. Of course, Selenium discontinued it. The DT200 and DT210 are excellent values for current models. Eminence's current titanium models aren't bad. That cheap phenolic model (APT something?) doesn't sound very good to me. P Audio has a few decent lower priced models. Link to comment Share on other sites More sharing options...
Members Kevin T Posted January 30, 2008 Members Share Posted January 30, 2008 What smoother alternative are there to That NASTY JBL ? Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 30, 2008 Members Share Posted January 30, 2008 Knowing how to eq? Link to comment Share on other sites More sharing options...
Members tlbonehead Posted January 30, 2008 Members Share Posted January 30, 2008 Knowing how to eq? But if you set them all on 12 your PA is a lot louder! Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 30, 2008 Members Share Posted January 30, 2008 But if you set them all on 12 your PA is a lot louder! Yeah, silly of me to have missed that Link to comment Share on other sites More sharing options...
Members moody Posted January 30, 2008 Author Members Share Posted January 30, 2008 Piezos will work and sound really good if you use them in a vertical array. If you use them in a cut and glued crossfired array you can get useful response down to 2k. The trade off is vertical dispersion which is not that critical IMO in most situations. Les Can you explain this further? I have no problem using piezos if they can be made to sound as good as any other driver, however for a vertical array using a lot of the things wouldn't you end up paying costs comparitive to a good compression driver anyway? Does a vertical array improve the horizontal dispersion of piezos (something I have noticed when I have heard them - laser beam to the front of the speaker cabinet). Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 30, 2008 Members Share Posted January 30, 2008 It's part of the Bill Fitzmaurice magic voodoo. If it's so wonderful and cheaper then what everybody else is doing, how come nobody else is STILL doing it. It will work, it will make noise, it may even sound ok but you trade one problem for another and in multiples if you count assembly labor (& hardware) it will cost more than what a single better quality compression driver costs. You also end up with multiple diffraction patterns due to the multiple spaced devices. Link to comment Share on other sites More sharing options...
Members preacherman672 Posted January 30, 2008 Members Share Posted January 30, 2008 It's part of the Bill Fitzmaurice magic voodoo. If it's so wonderful and cheaper then what everybody else is doing, how come nobody else is STILL doing it.It will work, it will make noise, it may even sound ok but you trade one problem for another and in multiples if you count assembly labor (& hardware) it will cost more than what a single better quality compression driver costs. You also end up with multiple diffraction patterns due to the multiple spaced devices. No voodoo magic just physics They sound really good and have even been compared A-B with JBL comp drivers and come out on top. They are real easy to make and require nothing more than a miter box, handheld miter saw, and some ABS plastic cement. Maybe an hour to make your first 6 piezo array, tops, and that's just because of figuring it out. Will cost way less than a comp driver no matter which way you look at. There are compromises, as I've mentioned vertical dispersion will be greatly reduced. Horizontal dispersion is increased with the cut and glued array up to 120 degrees. There are certain brands of piezos to avoid like the plague however. Pyle for one and some others. Check the links over at Bill's forums for the ones to avoid. I think WLE is another. In Europe I believe CPC piezos are considered good while the Goldwoods here in the states are the standard. Good luck and hope goes well. Les Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted January 30, 2008 CMS Author Share Posted January 30, 2008 No voodoo magic just physicsThey sound really good and have even been compared A-B with JBL comp drivers and come out on top. Physics can affect the dispersion, but not the quality of sound. As one who's dispelled the, "It's better than a JBL" claim for the Tuba sub, I have to question this JBL comparison as well. Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 30, 2008 Members Share Posted January 30, 2008 Don't forget the duct tape, chewing gum and bailing wire. I'll bet that's the key to making them sound better than the JBL drivers. It's a fine tooth comb filter, but fortunately the ear is pretty forgiving and it will work but as I have said before, if it's such an improvement, how come nobody else out there in speaker land is building speakers that way? Link to comment Share on other sites More sharing options...
Members preacherman672 Posted January 30, 2008 Members Share Posted January 30, 2008 The comb filtering only exists in the vertical plane, not the horizontal. If you wish to look at the A-B tests just go to Bill's site and search for David Perry. He built speakers with both JBL comp drivers and piezo arrays. He has a long and detailed description of his build and has built both the DR series, Titan subs and Wedgehorns. Link to comment Share on other sites More sharing options...
Members preacherman672 Posted January 30, 2008 Members Share Posted January 30, 2008 A bump for moody. There are several people from your neck o' the woods on Bill's board who would probably be more than willing to set a demo for you if they are local (i know nothing about Aussie geography) Just go to the forum and ask, no price for asking. Link to comment Share on other sites More sharing options...
Members moody Posted January 30, 2008 Author Members Share Posted January 30, 2008 A bump for moody. There are several people from your neck o' the woods on Bill's board who would probably be more than willing to set a demo for you if they are local (i know nothing about Aussie geography)Just go to the forum and ask, no price for asking. I did say at the very top of the thread that I am not actually even looking at the moment. If I did I would probably get one of the Selenium drivers that were recommended above and import them from the states (significantly cheaper than local). Price wise I could get away with about $40-45 a piece plus postage, I've seen some piezos cost that much. As to where I am situated. Parramatta, second largest city in Aus and about 30 minutes from the largest city in Aus so I'm sure there would be someone close by. Link to comment Share on other sites More sharing options...
Members moody Posted January 30, 2008 Author Members Share Posted January 30, 2008 A bump for moody. PS I was asleep, not much use bumping me at 5.30am. Link to comment Share on other sites More sharing options...
Members preacherman672 Posted January 30, 2008 Members Share Posted January 30, 2008 PSI was asleep, not much use bumping me at 5.30am. Ha ha. Sorry bout that. It's about 3 pm here and about 1 when i bumped lol Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted January 31, 2008 CMS Author Share Posted January 31, 2008 The comb filtering only exists in the vertical plane, not the horizontal. If you wish to look at the A-B tests just go to Bill's site and search for David Perry. He built speakers with both JBL comp drivers and piezo arrays. He has a long and detailed description of his build and has built both the DR series, Titan subs and Wedgehorns. I'll wait to hear a review from a less biased source. Ford thinks their cars are the best; do you take their word for it? Link to comment Share on other sites More sharing options...
Members tlbonehead Posted January 31, 2008 Members Share Posted January 31, 2008 I'll wait to hear a review from a less biased source. Ford thinks their cars are the best; do you take their word for it?I ask Bill what kind of cars are best! Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted January 31, 2008 CMS Author Share Posted January 31, 2008 I ask Bill what kind of cars are best! Something you can build in your backyard with a circular saw and polyurethane adhesive??? Link to comment Share on other sites More sharing options...
Members tlbonehead Posted January 31, 2008 Members Share Posted January 31, 2008 Something you can build in your backyard with a circular saw and polyurethane adhesive???Precisely! I do recall the car they built in Popular Mechanics once. Link to comment Share on other sites More sharing options...
Members moody Posted January 31, 2008 Author Members Share Posted January 31, 2008 I'll wait to hear a review from a less biased source. Ford thinks their cars are the best; do you take their word for it? Some of Fords cars are pretty good, they're called mazdas. As to the biased source, If you've spent that much time, money and effort making something that is the equivelent of something already available then of course you are going to justify it to yourself and others. I will believe the claims when I see and hear the items in a double blind test with all other factors being equal. And personally, I have a lot less time than money most of the time anyway. Link to comment Share on other sites More sharing options...
Members preacherman672 Posted January 31, 2008 Members Share Posted January 31, 2008 I'll wait to hear a review from a less biased source. Ford thinks their cars are the best; do you take their word for it? Did you actually read the review? It would be eye opening. Les Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted January 31, 2008 CMS Author Share Posted January 31, 2008 Did you actually read the review? It would be eye opening.Les I have no idea if what I read was the review. I searched his forum and found a post with him describing what you said. As I said, independent opinions matter, not preaching to the choir. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.