Hi,
a friend of mine recently salvage some old pa speakers from a cinema.
He got two bass cabinets from spanish speakers cinema brand KCS : the c-215 model. It's your typical passive double ported 15" bass cab. Along with it came one subwoofer (a double 18"), and two amps.
The two bass speakers came without the compression + horn that is usually mounted to it (model is kcs s801 driver + s201 horn).
So we're looking about how we can get it all to work in order for us to have a small PA system.
Our objective is to organize small concerts / parties in the countryside. So a stereo system obviously. Music played is everything from indie rock to traditionnal music (think old instruments) during live shows, to electronic music of all genre during parties.
Mostly outside, some small indoors places as well, not attached to a fixed venue. We are not a professionnal operation, think non profit diy concerts parties, we'll book local acts and dj friends.
I'm here to get recommandations about which compression + horn might pair nicely with it for our use. There is'nt a lot of data on the cabinets sadly, the only figure i get is the crossover frequency is pretty low at about 500hz. Best would be to get some measurements done, which we will defintely do when we get around to it.
I'm struggling to identify compression drivers that go this low for pa use (the obvious solution would be to add another way between the bass and the compression, but lets not for the moment).
In addition we'll have to get some active filters, if anyone has a good recommendation for something that can be found secondhand. Otherwise we'll have to get some budget stuff like behringer to start, i'd prefer to put the money on some good drivers first.
Thank you for reading,
a friend of mine recently salvage some old pa speakers from a cinema.
He got two bass cabinets from spanish speakers cinema brand KCS : the c-215 model. It's your typical passive double ported 15" bass cab. Along with it came one subwoofer (a double 18"), and two amps.
The two bass speakers came without the compression + horn that is usually mounted to it (model is kcs s801 driver + s201 horn).
So we're looking about how we can get it all to work in order for us to have a small PA system.
Our objective is to organize small concerts / parties in the countryside. So a stereo system obviously. Music played is everything from indie rock to traditionnal music (think old instruments) during live shows, to electronic music of all genre during parties.
Mostly outside, some small indoors places as well, not attached to a fixed venue. We are not a professionnal operation, think non profit diy concerts parties, we'll book local acts and dj friends.
I'm here to get recommandations about which compression + horn might pair nicely with it for our use. There is'nt a lot of data on the cabinets sadly, the only figure i get is the crossover frequency is pretty low at about 500hz. Best would be to get some measurements done, which we will defintely do when we get around to it.
I'm struggling to identify compression drivers that go this low for pa use (the obvious solution would be to add another way between the bass and the compression, but lets not for the moment).
In addition we'll have to get some active filters, if anyone has a good recommendation for something that can be found secondhand. Otherwise we'll have to get some budget stuff like behringer to start, i'd prefer to put the money on some good drivers first.
Thank you for reading,
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Lucky guy! Check out partexpress.com. Below is the 1st driver I came across that went down to 500hz. You will have to check them all to see which driver meets your needs frequency and cost wise.
https://www.parts-express.com/B-C-D...ssion-Driver-8-Ohm-4-Bolt-294-6072?quantity=1
"The 3" titanium diaphragm is optimized to deliver natural response from 500 to 18,000 Hz."
https://www.parts-express.com/B-C-D...ssion-Driver-8-Ohm-4-Bolt-294-6072?quantity=1
"The 3" titanium diaphragm is optimized to deliver natural response from 500 to 18,000 Hz."
Is that one dual 15" and one dual 18" box? Or multiples of each?
You will need what is referred to as a large format compression driver and horn combo, they typically have a 2" throat diameter with a 3-4" driver diaphram.
Examples would include but is not limited to the JBL 2445, B&C DE750, Selenium D3300, D4400. These are classic drivers now, that means you can sometimes find them at reasonable prices.. sometimes not, there are many more and there are modern drivers that could be candidates too but expect to pay $$.
You will also need an active crossover.. preferrably a DSP, and separate amplifiers for each section of the system.
https://www.ebay.com/itm/2263790142...Stb/uQ4RxkrBCtUiYqYUktA48=|tkp:Bk9SR8avhsyJZQ
You will need what is referred to as a large format compression driver and horn combo, they typically have a 2" throat diameter with a 3-4" driver diaphram.
Examples would include but is not limited to the JBL 2445, B&C DE750, Selenium D3300, D4400. These are classic drivers now, that means you can sometimes find them at reasonable prices.. sometimes not, there are many more and there are modern drivers that could be candidates too but expect to pay $$.
You will also need an active crossover.. preferrably a DSP, and separate amplifiers for each section of the system.
https://www.ebay.com/itm/2263790142...Stb/uQ4RxkrBCtUiYqYUktA48=|tkp:Bk9SR8avhsyJZQ
The easiest (wel documented) solution would be a B&C DCX464 in the acompagning ME464 horn. But it's a very expensive solution (and you will need dsp). It's a coaxial driver (2 compression drivers in one) that can cover the whole spectrum from 300Hz (altough 600Hz is safer to cross) to 20kHz, in one horn, and the ME464 is made specially for that driver and proven good. Crossing it at 500Hz with a higher order filter is no problem at all.
BMS and Celestion also makes drivers like that, and they are also very expensive. There are also other horns that can do that bandwith. But if you need to go that low you will need 2 bands of compression drivers, not 1, and those do it the best that i know of.
You can off course also use 2 seperate compression drivers and two horns, but that makes it more complex to build and it won't sound as good as a coax. Another option is to build a MEH top that fits it, but that is not easy to do (more for advanced diy speaker builders).
BMS and Celestion also makes drivers like that, and they are also very expensive. There are also other horns that can do that bandwith. But if you need to go that low you will need 2 bands of compression drivers, not 1, and those do it the best that i know of.
You can off course also use 2 seperate compression drivers and two horns, but that makes it more complex to build and it won't sound as good as a coax. Another option is to build a MEH top that fits it, but that is not easy to do (more for advanced diy speaker builders).
@BP1Fanatic thks, yes this b&c looks promising, in our budget, and doable with our limited skills (we ll get help for tuning the system regarding the dsp and all).
@conanski Thank you for your help, we got two dual 15" box, one 18" box. A second 18" would definitely be good, but it will have to do for now.
Yes the jbl would be nice if we can find it at a good price. I'm sure they sound fantastic, but i'm a bit cautious on getting vintage drivers for PA use, maybe i'm wrong. Yes of course we need active crossovers. I'm also inquiring about which model would suit our need. For amps we got two QSC USA 1310, would that be enough or do i need a third one (haven't really look at the power rating of each driver / amp yet)?
thanks.
@waxx thanks, the b&c coax seem like a very good option but a bit too expensive for us a the moment, maybe in the future.
MEH speakers i love them, would like to build some one day, but outside the scope of this project.
@conanski Thank you for your help, we got two dual 15" box, one 18" box. A second 18" would definitely be good, but it will have to do for now.
Yes the jbl would be nice if we can find it at a good price. I'm sure they sound fantastic, but i'm a bit cautious on getting vintage drivers for PA use, maybe i'm wrong. Yes of course we need active crossovers. I'm also inquiring about which model would suit our need. For amps we got two QSC USA 1310, would that be enough or do i need a third one (haven't really look at the power rating of each driver / amp yet)?
thanks.
@waxx thanks, the b&c coax seem like a very good option but a bit too expensive for us a the moment, maybe in the future.
MEH speakers i love them, would like to build some one day, but outside the scope of this project.
Well vintage in this case means non current model it doesn't mean civil war era..😉 Many of these were originally used in '80's and '90's high end PA speakers systems so they are plenty capable of that use, and it could be argued that modern DSP can provide even more protection than what they got originally. The only wear item is the diaphram/voice coil and changing it is an easy DIY job should it be necessary. The one thing you may want to add to the list is availability of genuine replacement diaphrams, there are chinese replacements available for almost anything but the quality is hit and miss.
There aren't as many rackmount speaker processors anymore but there are still a few, something like a Driverack Venue360 would be a good choice with it's modern features and processing. Even the Behringer DCX2496 will do a good job for not much money, it's a little noisier than the new stuff but has better features than the regular DRPA.
You need to dig up the specs on the speaker systems, it wouldn't be unusual to supply at least 500-1000w per driver to the 15's and 18's but the big CDs may only need 250w or so for clean output with no danger of amp clipping.
The two QSC amps you have would certainly power the 215's and CDs quite well, I have a similar rig that has been run for all it's worth with live bands and DJs. It's double 15 + 2" CDs (B&C DE750) over double 18, 1000w total for each 215, 2000w for each 218, processed by a DCX. Never blown a driver and the system has never sounded distressed even when pushed into limiting.. which DJs just love to do. 🙂 All the drivers in this system are non current models.
if it came with this horn you'd be all set!
interesting stuff for sure.
even this would do...that mid piques my interest.
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That 2x15 would probably work ok crossed at 800Hz, if 24dB/Oct or more. Most any 2”exit/3” coil driver will take that at PA levels. No problem finding a good $300-price-class driver. No idea if the current $200 class offerings are any good. The old Selenium D3300 was, but now NLA except to OEMs. They don’t want those falling into the hands of DIYers anymore. It’s was simply too good for the price paid, back when you could get them thru PE. Sure you could buy better - for $400+. You still can.
USA1310 is a little “light” for driving the 2X18 - bridged at 4 it runs hotter than the blazes of hell and damnation. Won’t just blow up, but I wouldn’t keep that up any longer than you have to. Find an RMX4050 or 5050 and run 1 driver per side - and you’ll toast the sub drivers before the amp cries uncle.
USA1310 is a little “light” for driving the 2X18 - bridged at 4 it runs hotter than the blazes of hell and damnation. Won’t just blow up, but I wouldn’t keep that up any longer than you have to. Find an RMX4050 or 5050 and run 1 driver per side - and you’ll toast the sub drivers before the amp cries uncle.
The original post already includes the specified system model and photo
Very much resembles the classic JBL 2380A horn and common used driver usually 2446H
4 bolt 2" throat, titanium drivers expect loading to 500 Hz common crossover 800 Hz
For Current availability with loading to 500 Hz with 800 Hz crossover.
B&C ME75 Horn
Specific driver designed for the application
B&C DE750TN
Otherwise a suitable 2" 4 Bolt Titanium Driver
within noted frequency range.
That doesn't change the fact that it will not sound homogeneous unless you have a listening distance of ~5m or more because of the great distances between the middle of the bass driver s and the middle of the horn.
Ok thanks for all your response. Yes getting the original KCS 801 horn +cd is definitely on the list of option (or getting other KCS related horn cd combo), but i need to find it in good condition and at a good price. I thought if the price difference between a vintage KCS matching horn + drivrer (which i know they get from a driver company) and a new driver + horn is not too great, i would go the new stuff.
Listening distance is non relevant : we will organize small concerts / parties in the countryside south of france, but we'll change places from event to event, so impossible to predict the exact configuration, altough like any event, most people won't be too close to the speakers.
Listening distance is non relevant : we will organize small concerts / parties in the countryside south of france, but we'll change places from event to event, so impossible to predict the exact configuration, altough like any event, most people won't be too close to the speakers.
Exactly, The original post included well defined info.
Small concerts / parties in the countryside more than enough to understand common variables.
Sounds like fun and good times ahead. Be fun to hear about your system and future events
Small concerts / parties in the countryside more than enough to understand common variables.
Sounds like fun and good times ahead. Be fun to hear about your system and future events
🙂 thanks, first events hopefully during the spring, so if anyone is in the area at that time, hit me up.
If the ME75 horn (also a variation of the JBL) is too expensive, there is also the P-Audio clone of that JBL horn, the PH-2380. I've used it a few times and it's quiet decent build. Lowest i crossed it was 600Hz with an old Selenium driver to replace a broken JBL horn on a cheap budget, and it does the job. I've used this horn also with a Faital HF-201 driver crossed at 800Hz (but that is to high for your purpose).
The ME75 is better build altough than he P-Audio, but the P-Audio is a lot cheaper and good enough for most purposes i think. It fits standard 2" drivers, both the Selenium and Faital work flawless with this horn.
The ME75 is better build altough than he P-Audio, but the P-Audio is a lot cheaper and good enough for most purposes i think. It fits standard 2" drivers, both the Selenium and Faital work flawless with this horn.
After scouring secondhand sites, i'm finding appropriate offers for jbl 2446+horn in pair. So might go this route.
One offers the 2446H so 8ohm, another one the 2446J so 16ohm. Would one be "better" over the other ? I should note the J offers is cheaper.
One offers the 2446H so 8ohm, another one the 2446J so 16ohm. Would one be "better" over the other ? I should note the J offers is cheaper.
Not enough difference to say which is "better" from a sound quality standpoint, but less voltage is required for the "J", 2.83v for one watt compared to 4v for the "H", so some money can be saved on the amplifier driving it.
If you are using a "constant directivity" horn like the JBL 2380 (or copies of the more than 40 year old design) ~+10dB is needed to flatten response above 7kHz:
The 8 ohm version allows +3dB more HF "boost" (actually -3dB less attenuation) to flatten response with passive crossovers.
I'd do a low level sine wave sweep test and buy the pair that sounds cleaner, noting the voltage required for the 8 ohm will be less for the same volume. If the driver buzzes, (easier to hear below 500Hz), either the diaphragms may be misaligned, defective, or the gap requires cleaning.
Also note the DC resistance should be 4.3 ohms (H), 8.5 ohms (J) ± 10% @ 25°C.
If not, the diaphragms may be aftermarket, which usually have crap response compared to the original, and often have not have been installed properly.
Art
If you are using a "constant directivity" horn like the JBL 2380 (or copies of the more than 40 year old design) ~+10dB is needed to flatten response above 7kHz:
The 8 ohm version allows +3dB more HF "boost" (actually -3dB less attenuation) to flatten response with passive crossovers.
I'd do a low level sine wave sweep test and buy the pair that sounds cleaner, noting the voltage required for the 8 ohm will be less for the same volume. If the driver buzzes, (easier to hear below 500Hz), either the diaphragms may be misaligned, defective, or the gap requires cleaning.
Also note the DC resistance should be 4.3 ohms (H), 8.5 ohms (J) ± 10% @ 25°C.
If not, the diaphragms may be aftermarket, which usually have crap response compared to the original, and often have not have been installed properly.
Art
No, it said:
Which is the opposite! It's your decision how relevant this part is but the initial information does not fit for this setup. I was mentioning it because I wanted to avoid disappointment. And my question about the listening distance was ignored too btw. but I'm not complaining, I just wanted to justify my concern for the distance because of the given info (not despite!).
The setup of the DSP got more influence on the sound than the drivers, got measurement equipment or someone who can do it for you? The suggested Behringer DCX 2496 will do nicely btw.
The S201 got a tuning of 44Hz, A low-cut at 40Hz is needed, much more important than a limiter, otherwise the voice coils will smash into the back pole plate far below the nominal power. For some music genres at events outside with no room gain you need subwoofers too. The B&C DE750TN got 20dB headroom anyway.
Get the B&C DE750TN, not the DE750. The TN is a lot better. Both need heavy EQing because of the breakup.
https://bcspeakers.com/en/products/hf-driver/2/16/DE750TN
@weltersys 🙏 Thank you for this detailed explanation, I'll take that into consideration. Responses like this are why i come and post here.
@ICG ok. i'm just saying, we don't really where we'll do our small events, the first couple ones we plan are outside at a public event place, beyond that we'll see we'd like to do stuff indoors but we didn't book anything in advance, it's a rural area, we'll see what opportunity arises. Hard to plan accordingly.
thanks for your additionnal advice : yes we are good friend with a couple of sound engineers who work in live sound, they'll help to get measurement and proper dsp fine tuning. The behringer dsp is what we had in mind, considering our budget it's pretty much the only one we can afford anyway at the moment.
Subwoofer : we got one 2x18" bass reflex cabinet. The first event will have pretty chill music during live shows so it will be ok. Oviously for party / dj purpose, we'd like get an additionnal one.
@ICG ok. i'm just saying, we don't really where we'll do our small events, the first couple ones we plan are outside at a public event place, beyond that we'll see we'd like to do stuff indoors but we didn't book anything in advance, it's a rural area, we'll see what opportunity arises. Hard to plan accordingly.
thanks for your additionnal advice : yes we are good friend with a couple of sound engineers who work in live sound, they'll help to get measurement and proper dsp fine tuning. The behringer dsp is what we had in mind, considering our budget it's pretty much the only one we can afford anyway at the moment.
Subwoofer : we got one 2x18" bass reflex cabinet. The first event will have pretty chill music during live shows so it will be ok. Oviously for party / dj purpose, we'd like get an additionnal one.
A matching width MEH with 4x 4" mids would get down to ~250Hz. Could be a good solution if you have the tools to DIY a cab. My 60cm wide 60x40 cab did this, with horizontal pattern control to 520Hz.
Rob.
Rob.