ryanjs Posted September 4, 2017 Posted September 4, 2017 Hi all, I've got a couple each of these drivers.. https://www.jaycar.com.au/25mm-titanium-dome-tweeter/p/CT2007 https://www.jaycar.com.au/6-5-paper-cone-woofer-midrange/p/CW2194 https://www.jaycar.com.au/12-response-paper-cone-woofer/p/CW2199 The amp I've got is capable of 2x300w, and this is the best crossover I've found that won't destroy my wallet.. http://www.ebay.com.au/itm/1PC-8ohm-3-Way-Audio-Speaker-Frequency-Divider-Treble-Bass-Crossover-600-4500Hz-/222552537772?hash=item33d12a3aac:g:RDAAAOSwPWRZSSko Obviously, I'll have to buy two of them. Question is, will this work? Or is there something better I could get? Cheers, Ryan
jtfoto Posted September 4, 2017 Posted September 4, 2017 Given the crossover point you might be better served with this https://www.jaycar.com.au/10-paper-cone-woofer/p/CW2198 I know it's only 10" but it may work better with that particular crossover. I have a very similar setup of DIY speakers and I bought the Kasun S-368C crossovers. They crossover at 800HZ and 4500Hz. Mine sound very good. 1
ryanjs Posted September 4, 2017 Author Posted September 4, 2017 Yeah I've already bought the 12" driver though aha. Thanks for the help guys!
Zaphod Beeblebrox Posted September 4, 2017 Posted September 4, 2017 On 04/09/2017 at 11:43 AM, ryanjs said: Hi all, I've got a couple each of these drivers.. https://www.jaycar.com.au/25mm-titanium-dome-tweeter/p/CT2007 https://www.jaycar.com.au/6-5-paper-cone-woofer-midrange/p/CW2194 https://www.jaycar.com.au/12-response-paper-cone-woofer/p/CW2199 The amp I've got is capable of 2x300w, and this is the best crossover I've found that won't destroy my wallet.. http://www.ebay.com.au/itm/1PC-8ohm-3-Way-Audio-Speaker-Frequency-Divider-Treble-Bass-Crossover-600-4500Hz-/222552537772?hash=item33d12a3aac:g:RDAAAOSwPWRZSSko Obviously, I'll have to buy two of them. Question is, will this work? Or is there something better I could get? Cheers, Ryan Expand There is no way of knowing how well it will work, as a crossover needs to be tailored to the impedance CURVE of the speakers. A generic crossover will provide a serviceable result and it will work, but the chances of it working well are about 1,000,000 :1. IOW: Not really much chance. As long as your expectations are not high, then go for it. Save your cash for a properly designed speaker. If you must take this approach, then why not buy local? https://www.wagneronline.com.au/3-way-150w-12db-octave/speaker-components/audio-speakers-pa/xn150-6852/2985/pd/ 3
mwhouston Posted September 4, 2017 Posted September 4, 2017 12" is OK for that Xover. Was it the Jaycar 12"? There are a few online box designers which will give you box size and port dementions for that driver. If you have trouble I can get the specs for you.
ryanjs Posted September 5, 2017 Author Posted September 5, 2017 Zaphod - That xover is only rated for 150w so I don't think that will work. Mwhouston - Yeah it is, and I've already made the box, and I was planning on keeping it sealed but I'll see how it sounds when I get to testing it out.
Zaphod Beeblebrox Posted September 5, 2017 Posted September 5, 2017 On 05/09/2017 at 1:22 AM, ryanjs said: Zaphod - That xover is only rated for 150w so I don't think that will work. Expand 150 Watt rating is ONE part of the equation. And a largely irrelevant one. The important stuff is to match the crossover to the impedance CURVE of the speakers. None of the crossovers under discussion will do that. If you want to increase the power handling of the crossover I cited, then just substitute higher Voltage capacitors. 24 minutes ago, ryanjs said: Mwhouston - Yeah it is, and I've already made the box, and I was planning on keeping it sealed but I'll see how it sounds when I get to testing it out. Expand It will be hit and miss. You would be MUCH better using a properly designed kit available from a number of sources, where it has been designed professionally and the crossover designed appropriately. 2
pete_mac Posted September 5, 2017 Posted September 5, 2017 On 05/09/2017 at 1:48 AM, Zaphod Beeblebrox said: 150 Watt rating is ONE part of the equation. And a largely irrelevant one. The important stuff is to match the crossover to the impedance CURVE of the speakers. None of the crossovers under discussion will do that. If you want to increase the power handling of the crossover I cited, then just substitute higher Voltage capacitors. It will be hit and miss. You would be MUCH better using a properly designed kit available from a number of sources, where it has been designed professionally and the crossover designed appropriately. Expand Absolutely 100% In my experience, off-the-shelf crossovers rarely work all that well. They are a 'blunt tool'. They may get you in the ballpark, but you will be a long way off an optimised design. You also won't have allowed for the different sensitivity of the different drivers. Proper crossover design caters for this. If using off-the-shelf crossovers with random drivers, you really need to have the capabilities of measuring the speaker once cobbled together and making changes to the crossovers afterwards.
mwhouston Posted September 5, 2017 Posted September 5, 2017 On 05/09/2017 at 2:28 AM, pete_mac said: Absolutely 100% In my experience, off-the-shelf crossovers rarely work all that well. They are a 'blunt tool'. They may get you in the ballpark, but you will be a long way off an optimised design. You also won't have allowed for the different sensitivity of the different drivers. Proper crossover design caters for this. If using off-the-shelf crossovers with random drivers, you really need to have the capabilities of measuring the speaker once cobbled together and making changes to the crossovers afterwards. Expand "L" pads can help balance differnt driver sensitivity. Of course you could have custome built Xover designed for $30 drivers and then your room turns all that cost and design to mush. I'm all for driver balance but in room and with ear and the rest of the system on music of choice. If it sounds good, it is good.
mwhouston Posted September 5, 2017 Posted September 5, 2017 There is plenty of online calculators for "L" pads.
pete_mac Posted September 5, 2017 Posted September 5, 2017 On 05/09/2017 at 2:50 AM, mwhouston said: "L" pads can help balance differnt driver sensitivity. Of course you could have custome built Xover designed for $30 drivers and then your room turns all that cost and design to mush. I'm all for driver balance but in room and with ear and the rest of the system on music of choice. If it sounds good, it is good. Expand Absolutely - but implementing L-pads by ear for a first-timer (which is what I'm assuming the OP is) is a real crapshoot. I'm not necessarily advocating having a full custom crossover designed by a third party... but having the ability to tweak the crossover based upon measurements (particularly in-room measurements) is very useful indeed IMHO. Each to their own though. 1
Zaphod Beeblebrox Posted September 5, 2017 Posted September 5, 2017 On 05/09/2017 at 2:50 AM, mwhouston said: "L" pads can help balance differnt driver sensitivity. Of course you could have custome built Xover designed for $30 drivers and then your room turns all that cost and design to mush. I'm all for driver balance but in room and with ear and the rest of the system on music of choice. If it sounds good, it is good. Expand No. This is really, REALLY bad advice. The correct (no, the ONLY) way to do the job is to do the calculations, based on the measured curves of the drivers. In that sense, an amateur should simply build an already worked out design. Starting with a generic crossover is not a good way to go. This: http://www.erseaudio.com/Second-Order-3-Way Would be a far better way to start, after, of course, obtaining an impedance curve of the individual drivers. If you imagine ANY speaker manufacturer that has pretensions to build a decent product, uses an off-the-shelf crossover, then you are in for a very rude shock. 3
Nigel Posted September 5, 2017 Posted September 5, 2017 On 05/09/2017 at 3:04 AM, pete_mac said: having the ability to tweak the crossover based upon measurements (particularly in-room measurements) is very useful indeed IMHO. Each to their own though. Expand +1 - these measurements are microphone and software (eg REW) measurements, as opposed to what ZB is talking about (electronic). As Pete suggests, adjusting the crossover components can help reduce room effects/problems. eg move the xo point towards or awat from some boost or cancellation. I got a fantastic FR plot and waterfall plot, but I suspect that the inductor & cap values are not what any of the calculators would recommend. (I could be wrong about that - never checked). but why not deal with the room at the same time.
A9X Posted September 5, 2017 Posted September 5, 2017 I agree with Zaph; there is no way a generic xover will work well with 2 random drivers. As well as needing to be designed for the impedance curves of all the drivers, it needs to take into account baffle width (ta account for baffle step) and the distortion curves of the drivers amongst other things. For example, as tweeters are driven lower in frequency, the distortion will rise rapidly so you need to measure and determine where to cross to minimise this. There is considerably more to designing a good speaker than throwing a couple of drivers in a box and adding some random xover. If you want to build your own speaker, there are only two ways to do it well; 1: build a kit that someone else has already designed. There are heaps of them out there. Give a budget and what sort of performance you're looking for, and I'll offer some suggestions. 2: spend a lot of time learning the theory, get all the appropriate tools, especially measurement gear, then learn how to use that and what the measurements actually mean, start asking questions and learn off others. Then you can start designing from scratch. Ideally, #1 will come before #2. From what you've asked, you are nowhere near ready for #2. I say this not to discourage, but because it's the truth. I'd really rather see a new DIYer successfully complete a project and end up with a good speaker (or whatever) than end up with something substandard and have wasted their money and effort. 2
Paul Spencer Posted September 5, 2017 Posted September 5, 2017 Is this for a school project? My first speaker project was a school project for Physics class. I did everything wrong but still managed to get an A! Luckily for me, our Physics teachers knew more about physics than speaker design. If you can tell us a bit more about your project, perhaps we can give some more useful suggestions. One of your problems is that a school project will have a limited scope and a limited budget. You will probably find just one small part of this will blow the budget and take a lot of time. If you buy an off the shelf crossover, then consider just buying one and picking up a measurement mic to show how it goes wrong. Or it might be enough just to model and design a ported box. You can also pick up an active crossover fairly cheaply and use your amp to drive just one 2 way speaker. Rest assured any off the shelf passive crossover won't work well for any real world design at all. They use the bare minimum of parts to provide textbook electrical filters. Any half decent crossover is adjusted so that the hand fits the glove. The values move away from the theoretical textbook values to compensate for driver roll off, baffle effects and driver sensitivities. Any good design will also work through some issues that aren't knowable until you have that very specific network of decisions on the table. A smart design might actually do more with less. Sometimes a cap of just the right value does a better job than four parts designed with a textbook filter. (Not for the reasons you might read in the brochure!) 2
Happy Posted September 5, 2017 Posted September 5, 2017 So what are those generic XO for? Strictly school project only? Sent from my iPad using Tapatalk
mwhouston Posted September 5, 2017 Posted September 5, 2017 "Will this crossover work". Yes is the answer. 1
Sub Sonic Posted September 5, 2017 Posted September 5, 2017 But will it work well? Highly unlikely, as others have stated. Regards, SS
mwhouston Posted September 5, 2017 Posted September 5, 2017 (edited) On 05/09/2017 at 9:28 AM, Sub Sonic said: But will it work well? Highly unlikely, as others have stated. Regards, SS Expand Yes is the answer. It will work well. With the drivers involved it will work very well. Once more though driver balancing is required. My two 15" Beyma concentrics drivers cost me $2000 landed. My Xovers (wound my on chokes) cost about $30 all up including balancing resistors. The Xovers will work. Edited September 5, 2017 by mwhouston
zog Posted September 5, 2017 Posted September 5, 2017 Always been curious what running up a straightforward Xover using some measurement and application of PCD or similar would deliver with those Jaycar drivers :-) PCD = http://audio.claub.net/software/jbabgy/PCD.html
pete_mac Posted September 6, 2017 Posted September 6, 2017 On 05/09/2017 at 9:14 AM, mwhouston said: "Will this crossover work". Yes is the answer. Expand It's a bit like asking 'will these 13" wheels and tyres work on my Toyota Landcruiser?' In a physical sense, yes, the car will roll down the road, so I guess they would work. It doesn't mean that's is anywhere near optimal though. 2
mwhouston Posted September 6, 2017 Posted September 6, 2017 (edited) On 06/09/2017 at 12:17 AM, pete_mac said: It's a bit like asking 'will these 13" wheels and tyres work on my Toyota Landcruiser?' In a physical sense, yes, the car will roll down the road, so I guess they would work. It doesn't mean that's is anywhere near optimal though. Expand I have built a few two way and three way speakers with Jaycar drivers and once used Jaycar Xovers which I upgraded the caps from NP to Polies. All good. For the money they are really good value and when there is a Jaycar store near your door and most stores are happy to help - how can you go wrong. I'd bet, if made properly, these speakers will outperform any commercial offering at 5 X the price. I'm assuming here about $300 - $500 as a finished price. I've have repaired commercial speakers for friends and are often appalled at the low grade drivers and Xover for so called well know commercial brands. And the hookup wire is a laugh. The answer is still "YES"! If the drivers were $1000 each I'd be looking very closely at the Xovers to ensure I get my bangs for bucks. But not here. These will be good sounding DIY speakers at a low price and will probably compare well to low priced commercial speakers. Here is a question with relation to these speakers;- what is the gear, preamp and power, driving them. Efficiency will be about 88db/M/W. Edited September 6, 2017 by mwhouston
Zaphod Beeblebrox Posted September 6, 2017 Posted September 6, 2017 On 05/09/2017 at 10:13 AM, mwhouston said: Yes is the answer. It will work well. With the drivers involved it will work very well. Once more though driver balancing is required. My two 15" Beyma concentrics drivers cost me $2000 landed. My Xovers (wound my on chokes) cost about $30 all up including balancing resistors. The Xovers will work. Expand You cannot possibly know this, unless you have used those drivers with the same crossover and plotted the result. You are just engaged in wild speculation. Will the crossovers work? Yes. Will they work well? Absolutely not. Like I said, it's a million to one shot. Proper speaker designers do not work on wild speculation or million to one shots. They resort to careful measurements and lots of calculations (often performed in CAD software).
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