Hi guys,
I'm trying to sort out a 15" two-way system. The mid-bass driver will be a Beyma 15P1200Nd [PDF].
Thus far, I've been playing with some 1" compression drivers that're 35w (pink noise) rated, and good for 1kHz. Using a DCX2496 and some measurement gear, I've managed to get a rather good sound out of them with a ~1.2kHz crossover point, but ideally those CDs would go back in their cabinets for monitor use. I also don't know if these drivers are hefty enough to keep up with those 15"s at high power.
So, I'd like to find another set of compression drivers and horns. Of course, I'd like them to be as cheap as possible, but while still doing it "right".
Do I use a 2" exit driver, a 1.4", or will a 1" driver suffice?
Looking online so far, few 1" drivers will reach 1kHz, 1.4" drivers are quite rare, and 2" drivers are just expensive. Does anyone have any specific drivers that they like?
The goal is a nice-sounding 15" two-way cabinet with plenty of output for live music and parties.
Photos and graphs coming soon.
Chris
I'm trying to sort out a 15" two-way system. The mid-bass driver will be a Beyma 15P1200Nd [PDF].
Thus far, I've been playing with some 1" compression drivers that're 35w (pink noise) rated, and good for 1kHz. Using a DCX2496 and some measurement gear, I've managed to get a rather good sound out of them with a ~1.2kHz crossover point, but ideally those CDs would go back in their cabinets for monitor use. I also don't know if these drivers are hefty enough to keep up with those 15"s at high power.
So, I'd like to find another set of compression drivers and horns. Of course, I'd like them to be as cheap as possible, but while still doing it "right".
Do I use a 2" exit driver, a 1.4", or will a 1" driver suffice?
Looking online so far, few 1" drivers will reach 1kHz, 1.4" drivers are quite rare, and 2" drivers are just expensive. Does anyone have any specific drivers that they like?
The goal is a nice-sounding 15" two-way cabinet with plenty of output for live music and parties.
Photos and graphs coming soon.
Chris
Looking at the PDF file for that Beyma 15, it looks like a bass driver & seems a bit rough above 300Hz. Are you expecting it to double as both a mid & a subwoofer driver? 1200Hz is about the highest you might want to cross over to a 15" mid.
"...1.4" drivers are quite rare..." Almost every major pro audio brand has a 1.4" compression driver, including Beyma. Some 2" & 1.4" drivers share the same diaphragm diameter, but vary the exit size for a different response. I'm partial to Radian for large-format drivers. Their aluminum alloy diaphragm with mylar surround sound smoother to me than titanium.
Personally (assuming that you're using a wide-dispersion HF horn), I wouldn't pair a 1" driver with a 15" cone. Either the 1" will be playing too low, or the 15 will have to be crossed too high & start to beam and/or roll off. For hard-hitting sound reinforcement, I wouldn't trust most 1" drivers below 1500Hz, or under 2kHz if they're cheapies. There are exceptions, like the BMS line.
Umm...why would you spring for a high-quality 15" cone, then pair it with a HF section for "as cheap as possible"? You may be flirting with disappointment.
"...1.4" drivers are quite rare..." Almost every major pro audio brand has a 1.4" compression driver, including Beyma. Some 2" & 1.4" drivers share the same diaphragm diameter, but vary the exit size for a different response. I'm partial to Radian for large-format drivers. Their aluminum alloy diaphragm with mylar surround sound smoother to me than titanium.
Personally (assuming that you're using a wide-dispersion HF horn), I wouldn't pair a 1" driver with a 15" cone. Either the 1" will be playing too low, or the 15 will have to be crossed too high & start to beam and/or roll off. For hard-hitting sound reinforcement, I wouldn't trust most 1" drivers below 1500Hz, or under 2kHz if they're cheapies. There are exceptions, like the BMS line.
Umm...why would you spring for a high-quality 15" cone, then pair it with a HF section for "as cheap as possible"? You may be flirting with disappointment.
Hi Joe,
To answer your questions...
I'm looking for 45Hz-xHz from the 15". I want enough low end extension to not miss a subwoofer. So far, I can eek 1.3kHz out of it, but there's some EQ involved there. Pics below - 2nd one is taken a few inches out from the woofer's surround, almost along the cone profile.
Given that the latter is fairly far off-axis, I think its safe to aim for 800Hz-1kHz.
Over here, it seems difficult to get hold of 1.4" drivers, though they would appear to be the ones to go for. Horns for them are even more difficult to obtain. I spotted the Faital Pro HF144 as a candidate - that's happy down to 700Hz, but power handling improves if you only go to 900. Since its not a particularly high-power application, there's some lee-way there.
Attached is a PDF of the current HF driver I'm using. The manufacturer claims 1kHz performance from this driver, but thermal power handling is fairly limited - perhaps this was their chosen compromise?
To answer your last question - I'm looking for a solution that's as cheap as possible, but still doing the job properly. If that means buying a pair of compression drivers for £300, then fair enough. What I don't particularly want to hear about is the perfect device for the job that'll cost £3000.
Cheers
Chris
PS - here's what I've got out the compression driver after EQ.
To answer your questions...
I'm looking for 45Hz-xHz from the 15". I want enough low end extension to not miss a subwoofer. So far, I can eek 1.3kHz out of it, but there's some EQ involved there. Pics below - 2nd one is taken a few inches out from the woofer's surround, almost along the cone profile.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Given that the latter is fairly far off-axis, I think its safe to aim for 800Hz-1kHz.
Over here, it seems difficult to get hold of 1.4" drivers, though they would appear to be the ones to go for. Horns for them are even more difficult to obtain. I spotted the Faital Pro HF144 as a candidate - that's happy down to 700Hz, but power handling improves if you only go to 900. Since its not a particularly high-power application, there's some lee-way there.
Attached is a PDF of the current HF driver I'm using. The manufacturer claims 1kHz performance from this driver, but thermal power handling is fairly limited - perhaps this was their chosen compromise?
To answer your last question - I'm looking for a solution that's as cheap as possible, but still doing the job properly. If that means buying a pair of compression drivers for £300, then fair enough. What I don't particularly want to hear about is the perfect device for the job that'll cost £3000.
Cheers
Chris
PS - here's what I've got out the compression driver after EQ.
An externally hosted image should be here but it was not working when we last tested it.
One cheap way to get a 2" compression driver here is buy a pair of used Peavey SP2 or SP5 speakers, usually $600 for the former. Take a piano CD to check that they are working. SP2 is 15" 1505-8KADT Black widow woofer + 2" CD (22XT CD) which is titanium. The crossover point in the SP2-XT is 1200 hz. the Beam width is 60 degree, so install in a long room. My SP2-XT's are on poles around and above the piano at one end of a room, and the listening chair is centered at the other end of the room 14' away.
The SP5 has a smaller woofer, I never downloaded the datasheet because I didn't like the bass on piano compact disk source material at the store in town.
There are 22XT CD parts all over the internet from high volume resellers, but the language of the description is always so vague I'm afraid I would be buying a plastic ring for $60. I think the driver is $99 (USA) but I'm not sure.
The SP5 has a smaller woofer, I never downloaded the datasheet because I didn't like the bass on piano compact disk source material at the store in town.
There are 22XT CD parts all over the internet from high volume resellers, but the language of the description is always so vague I'm afraid I would be buying a plastic ring for $60. I think the driver is $99 (USA) but I'm not sure.
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I guess the one concern is the system's intended use for live music. A single 15 per side raised off the ground isn't going to provide a lot of high-impact bass above the typical stage volume of a live band.
I like the DAS product line. If they claim their 1" comp can play to 1Khz, it probably can. However, every driver is excursion-limited. A possible drawback is that distortion in its upper range could be introduced if the driver is pushed too hard crossed at the lowest recommended point. If you can get away with 1.3kHz, do it. You might also consider the added complication of inserting a smaller cone like an 8" between the 15 & comp.
The other way to go would be to build a 2x15 sub & pair the HF with a 10" or 12" cone, then add a 2nd sub when you can afford it.
There's always plenty of better options which exceed our budgets!
I like the DAS product line. If they claim their 1" comp can play to 1Khz, it probably can. However, every driver is excursion-limited. A possible drawback is that distortion in its upper range could be introduced if the driver is pushed too hard crossed at the lowest recommended point. If you can get away with 1.3kHz, do it. You might also consider the added complication of inserting a smaller cone like an 8" between the 15 & comp.
The other way to go would be to build a 2x15 sub & pair the HF with a 10" or 12" cone, then add a 2nd sub when you can afford it.
There's always plenty of better options which exceed our budgets!
Not gonna happen, at low levels it'll sound good enough but as you crank it up the midrange vocal clarity will go in the toilet because it gets modulated by the 15" driver moving at high excursion reproducing the low frequency content. The solution is a 3-way system.. either a smaller dual 10+1 with a separate 15" or 18" sub or a 15" 3-way all-in-one box with an 8" mid driver.
Right, plenty of newbies invest in big herkin' 2x15 top boxes (usually with pathetic 1" drivers crossed too high), thinking that they have cleverly avoided the need for subs. After they finally buy or build proper subs, they find that they must now lift the big herkin' 2x15 tops to stack on the subs...!
I use and like the Radian 850pb, but bought them second hand from eBay in the US for a lot cheaper than here. Mine are oddly 3" diaphragms through a 1.5" exit. You can see them on my conical horns here
Loads of people use the B&C DE250 (used in Gedlee speakers) and is revirewed as one of the best 1" drivers, for the money.
I toyed with the idea of building a synergy/unity style horn with the B&C CD and then the closed back Pyle drivers which are dirt cheap. A great way to get point source and low enough to cross to an actual sub.
Loads of people use the B&C DE250 (used in Gedlee speakers) and is revirewed as one of the best 1" drivers, for the money.
I toyed with the idea of building a synergy/unity style horn with the B&C CD and then the closed back Pyle drivers which are dirt cheap. A great way to get point source and low enough to cross to an actual sub.
I really don't want to go for a true 3-way. A 2-way with a big CD and a bullet super tweeter, I can deal with. I am, however, tired of trying to get 12" tops and subs into tiny hatchbacks and taxis.
I've tried the current set-up with some music from AVS forums: they have an infrasonic music thread somewhere. Running up to ~150w waaaaay below the current cabinet's tuning, excursion got to near Xmax, but the midrange stayed clean. I was both surprised and impressed - other speakers I tried it on clearly exhibit the problems you've described.
I have considered the DE250 - IIRC it'll get down to 800Hz nicely. Anyone know if it'll take some stick at those frequencies?
As it happens, I have a few Peavey speakers around. They're the HiSys 12" two-way ones. Think its HiSys-1 XT..?
Anyway, I'll open them up and have a look at the CD. I'm selling them on for someone, so I suppose I could break a pair of cabinets and sell the parts seperately.
If the weather's nice any time soon, I'll see how the current setup sums off-axis. More pretty (or not) graphs!
Cheers, all.
Chris
The hf144 will take 80w at 900hz. It's 109db/w/m but even padded down a bit that should generate enough volume. That takes the tricky higher stuff away from the beyma near its breakup point
A 15+2 would be one way around it but so would be a 3-way using an 8" coaxial mid with a 1" CD mounted on it and maybe cross at 500hz and 2.5khz, the box is no bigger maybe even smaller than it would be with the big 2" exit horn.. which has to be pretty big to reach down to 1khz.
The 3" diaphragm is typical of the Radian large-format drivers, but the 850PB has a 2" exit. The 1.5" exit is the odd part.
A decent 2" that won't break the bank is the Selenium D3305. 3" diaphragm, 2" exit. While not as good as typical $500-600 solutions, they beat the snot out of any 1" at 1 KHz, and will cross down at 800. I run mine at 1k with dual 12's. The D3300 is better, but they are $200 (that's still inexpensive though) and weigh as much as most 15's.
Managed to get hold of a pair of ElectroVoice DH1a compression drivers. 3" diaphram, 2" exit. They're currently on HP64 horns, part of the Deltamax cabinets I picked up.
The magnets are 9" across!
Something tells me they'll be adequate. Link to PDF.
The horn currently installed "provides good acoustic loading at all frequencies above 1000Hz". I guess that's my lower crossover limit, then.
The cabinets would still allow an 8" coaxial unit to be installed if I chose, but preliminary results are promising. Of course, I'm messing with EQ and REW to get it close, but it really isn't far off. Methinks they'll have a lot more headroom than the Das CDs, too.
Pics tomorrow.
Chris
PS - port tuning is approximately 50Hz - checked by putting the measurement mic right next to the woofer cone and sweeping - there's a dip in output in the 45-55Hz range.
The magnets are 9" across!
Something tells me they'll be adequate. Link to PDF.
The horn currently installed "provides good acoustic loading at all frequencies above 1000Hz". I guess that's my lower crossover limit, then.
The cabinets would still allow an 8" coaxial unit to be installed if I chose, but preliminary results are promising. Of course, I'm messing with EQ and REW to get it close, but it really isn't far off. Methinks they'll have a lot more headroom than the Das CDs, too.
Pics tomorrow.
Chris
PS - port tuning is approximately 50Hz - checked by putting the measurement mic right next to the woofer cone and sweeping - there's a dip in output in the 45-55Hz range.
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You really scored with the EV drivers & horns! Now, you can safely cross low enough & not worry about cooking a 1" comp. The DH1A sags a bit at the top, so it does need some EQ. With a 60* horn, you might consider crossing a little higher than 1kHz for better DI matching. Now that you have your HF sorted, I don't think you need to consider an 8" mid anymore. Instead, perhaps you might work toward replacing the sub 15's in your top boxes with mid 15's, then build a separate sub with them. Eventually, you'll want dedicated subwoofers!
Hey Joe,
The 15"s hit cone break-up a little around 1.6kHz, so I don't think I'll be going too far above 1kHz.
Next time I want subs, they're gonna be big. For now, I quite like having a pair of boxes that actually sound full-range: most stuff sounds anaemic to me, as tops are often -10dB at 60Hz, so having flat-to-50 performance is rather nice.
The 15"s hit cone break-up a little around 1.6kHz, so I don't think I'll be going too far above 1kHz.
Next time I want subs, they're gonna be big. For now, I quite like having a pair of boxes that actually sound full-range: most stuff sounds anaemic to me, as tops are often -10dB at 60Hz, so having flat-to-50 performance is rather nice.
Couple of pics.
First, the Das tweeters sat on top of the EV cabs. At that point, I didn't know if the EV CDs worked. NB - the mounting clamps will be cut down a bit as a couple of them just touch the woofer surround.
And here's the compression drivers. I said the EV one was big...
Chris
First, the Das tweeters sat on top of the EV cabs. At that point, I didn't know if the EV CDs worked. NB - the mounting clamps will be cut down a bit as a couple of them just touch the woofer surround.
An externally hosted image should be here but it was not working when we last tested it.
And here's the compression drivers. I said the EV one was big...
An externally hosted image should be here but it was not working when we last tested it.
Chris
Your build looks clean & professional. Yeah, I remember those EV comps as being pretty beefy. You're not really going to run the box upside-down, are you? It's better to keep the DAS tweets close to the DH1A (assuming you're using a proper Xover between them).
DI Matching is all about crossing your mid driver at the point where its dispersion matches the horizontal dispersion of the HF horn. As a generalization, the narrower your HF horn splay is, the higher your mid Xover needs to be for the mid to collapse enough to make a smooth transition. Otherwise, you'll have uneven off-axis response. The best way to determine your Xover point is to take measurements.
DI Matching is all about crossing your mid driver at the point where its dispersion matches the horizontal dispersion of the HF horn. As a generalization, the narrower your HF horn splay is, the higher your mid Xover needs to be for the mid to collapse enough to make a smooth transition. Otherwise, you'll have uneven off-axis response. The best way to determine your Xover point is to take measurements.
The build was done by EV themselves a number of years ago - I got the cabinets and horns, and the working drivers were a welcome surprise.
They'll be working as a 15"+2 system for now - the Das CDs are going back into the RF12 cabinets and used for monitoring and smaller gigs - certainly better than an old Peavey 1x10 I had been using.
IIRC, the HP64 horn lets go of its 60x40 dispersion below 1.6kHz-ish. Here's a link to the PDF. That looks like a +/- 70 degree beamwidth at 1kHz, so I think I'll aim slightly higher than that. The 1.3kHz crossover I have at the minute sounds very nice.
The cabinets are going to be out gigging this weekend, so I'm looking forward to using them in anger. There'll be 700w/ch behind the woofers and 200w/ch behind the tweeters. Should be plenty. Hoping to get more power behind the woofers at some point, but that's not a huge priority - only a couple of decibels to be gained.
There's no pole mounts on the underside, so they're gonna be sat on a table at each side. They'll be on a stage, and the cabs are pretty tall, so I think that'll be enough. If all goes well this weekend, the next job will be to make some speaker stands that can be erected once the speakers are in place.
Cheers
Chris
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