Gotta love the passion for this style! I need to check out this genre more. Looks like Downbeat has some various artists discs...
One other vintage trick you could employ would be to use a tube or similar class A compressor after the pre. A good compressor can add ALOT of mojo.
Brian, a RLH acts like a FLH whereas the system f3 will drop if a v-plated, right?
One other vintage trick you could employ would be to use a tube or similar class A compressor after the pre. A good compressor can add ALOT of mojo.
Brian, a RLH acts like a FLH whereas the system f3 will drop if a v-plated, right?
Downbeat was the soundsystem of Coxonne Dodd, who was also the owner of the Studio One studio and record company (including a whole leap of labels) that is mostly responsible of for the birth of ska, rocksteady and reggae and dominated the regggae scene from the late 50's (as Worldisc) till the late 70's. Downbeat was first (founded in the early 50's as rythem & blues sound system) and the studio and label was a logical progression in that time. Everybody in that time, including Bob Marley recorded there...
And if you want to see soundsystem culture alive, you need to come to europe. The biggest dances are in the summer in open air. Big yearly events to check are Nottinghill Carnival (London), International Dub Gathering (Alicante, Spain), Reggaebus (Charleroi, Belgium), Dubcamp (Nantes, France), ... But there are soundsystem dances all over europe every weekend, and in 99% of the cases on custom build high power sound systems with a lot of subbass, and mostly with scoops or hog scoops as sub.
And if you want to see soundsystem culture alive, you need to come to europe. The biggest dances are in the summer in open air. Big yearly events to check are Nottinghill Carnival (London), International Dub Gathering (Alicante, Spain), Reggaebus (Charleroi, Belgium), Dubcamp (Nantes, France), ... But there are soundsystem dances all over europe every weekend, and in 99% of the cases on custom build high power sound systems with a lot of subbass, and mostly with scoops or hog scoops as sub.
Last edited:
Hog scoop really is pretty good design, modern version of classic scoop. It goes lower and has less upper bass dip. Overall better all-round subwoofer than classic scoops. However, it is not that easy to build and takes some time compared to standard reflex enclosures.. but loaded with good driver it might be worth it.
I have made two Hogs, one for my friends livingroom as he wanted some serious bass so I made him happy!
Loaded with Fane 18SB which is not the best HOG / scoop driver (spl wise), it still produces some huge SPL, moves lots of air and sound quality is pretty nice and warm!
Hog scoop is good for up to 80-100Hz and this design needs also some kick-bass enclosures for upper bass regions.
Ok, two videos of it (highly distorted sound sorry about that):
temp
And some bass tunes, everything was shaking really bad!
temp
Bassreflex is propably the "safest" way to go - good compromise. Check out RCF esw1018 plans too!
I have made two Hogs, one for my friends livingroom as he wanted some serious bass so I made him happy!
Loaded with Fane 18SB which is not the best HOG / scoop driver (spl wise), it still produces some huge SPL, moves lots of air and sound quality is pretty nice and warm!
Hog scoop is good for up to 80-100Hz and this design needs also some kick-bass enclosures for upper bass regions.
Ok, two videos of it (highly distorted sound sorry about that):
temp
And some bass tunes, everything was shaking really bad!
temp
Bassreflex is propably the "safest" way to go - good compromise. Check out RCF esw1018 plans too!
Last edited:
Hi
If you don't want a pre but want to keep it analog and still play the machine like an instrument look at a meyer cp10 equalizer, looks like a reggae pre but is better
Crest xr20 is also rackmounted and has so many routing options to dub it away.
Delay, boss de 200 is cheap and nice, but the Real thing is the space echo or similar vintage tape delay, not cheap at all and needs maintenance.
Find an analog crossover with good mute switches to temporary kill bands, or you could put another crossover before the mixer and control and mute the single frequency bands with it, and as bonus separate fx sends for subs mids highs...
If you really want the functionality of a reggae pre with analog gear it is gonna cost you more - but probably sound better and be more flexible.
And you need vu meters somewhere in there...
I've gone more rational and modern with my sound, tapped horns and dsp, but I understand the appeal of such a full analog rack and vintage stack... But I allready find my class d amps heavy!
If you don't want a pre but want to keep it analog and still play the machine like an instrument look at a meyer cp10 equalizer, looks like a reggae pre but is better
Crest xr20 is also rackmounted and has so many routing options to dub it away.
Delay, boss de 200 is cheap and nice, but the Real thing is the space echo or similar vintage tape delay, not cheap at all and needs maintenance.
Find an analog crossover with good mute switches to temporary kill bands, or you could put another crossover before the mixer and control and mute the single frequency bands with it, and as bonus separate fx sends for subs mids highs...
If you really want the functionality of a reggae pre with analog gear it is gonna cost you more - but probably sound better and be more flexible.
And you need vu meters somewhere in there...
I've gone more rational and modern with my sound, tapped horns and dsp, but I understand the appeal of such a full analog rack and vintage stack... But I allready find my class d amps heavy!
I have decided to double the number of subs and 15s.
So (4) quad 18's (JBL 2245H), (4) double 15's (JBL 2226H), (4) 2 inch compression drivers (JBL2445H) and (8) JBL2404 tweeters. So 4 way.
Bass reflex quads and 15's, wooden multi cell horns.
I am getting old JBL speakers re-coned for as new speakers.
I have been cautioned on using these JBL 2245H drivers because they are relatively low powered compared to others. Maybe doubling the number of subs will help.
I have been cautioned on the size of the quad cabinets for getting into venues. Yeah I'm going to be ferked there.
I have been cautioned that valve amps are unwise but Paul Axis and a number of others are successfully using them so forward!
I have been recommended hogs, scoops etc. But I like the idea of a flatter frequency response.
I have been cautioned on the unnecessary expense of going all analogue but I'll do it anyway.
I will play digital music sources (HD24XR digital multitrack, CD's, laptop) as well as vinyl. But just want to minimise unnecessary conversions in and out of amps etc.
I don't want to be the biggest, loudest scoop sound at a european festival. Just a nice dance with not too big a mass of humans.
Is there any reason I may be doomed for failure?
I'm acquiring speaker frames for re-coning as we speak. After the friendly, informative and humorous participation, I feel I should update with progress photo's of sound system porn.
Give thanks,
Roman.
So (4) quad 18's (JBL 2245H), (4) double 15's (JBL 2226H), (4) 2 inch compression drivers (JBL2445H) and (8) JBL2404 tweeters. So 4 way.
Bass reflex quads and 15's, wooden multi cell horns.
I am getting old JBL speakers re-coned for as new speakers.
I have been cautioned on using these JBL 2245H drivers because they are relatively low powered compared to others. Maybe doubling the number of subs will help.
I have been cautioned on the size of the quad cabinets for getting into venues. Yeah I'm going to be ferked there.
I have been cautioned that valve amps are unwise but Paul Axis and a number of others are successfully using them so forward!
I have been recommended hogs, scoops etc. But I like the idea of a flatter frequency response.
I have been cautioned on the unnecessary expense of going all analogue but I'll do it anyway.
I will play digital music sources (HD24XR digital multitrack, CD's, laptop) as well as vinyl. But just want to minimise unnecessary conversions in and out of amps etc.
I don't want to be the biggest, loudest scoop sound at a european festival. Just a nice dance with not too big a mass of humans.
Is there any reason I may be doomed for failure?
I'm acquiring speaker frames for re-coning as we speak. After the friendly, informative and humorous participation, I feel I should update with progress photo's of sound system porn.
Give thanks,
Roman.
Roman,
Wouldn't want to comment about negative personal issues, let's stick to the technical side :^).
Art
I will mostly play recordings for people to dance to. But if I study PA limitations then maybe I could mic up a band and mix them myself.
I wouldn't trust others with the dangers of toasting my drivers. Big responsibility.
Perhaps I am limited in terms of power for the extra headroom needs of live music? I have read the crest 'how much amp power do I need?' webpage and it seems amps need to deal with huge dynamic peaks of 10-20db with live music.
Maybe compressors and limiters could reduce the dangers here.
I'm sure with some more knowledge I can at the very least put safe guards in place to avoid driver damage from amp overload causing clipping and driver over excursion.
I am a total novice throwing out buzzwords to sound knowledgeable.
But I have read a few things and these are the dangers I have read about.
I own a copy of Yamaha Sound Reinforcement book. That probably will answer all my questions.
I wouldn't trust others with the dangers of toasting my drivers. Big responsibility.
Perhaps I am limited in terms of power for the extra headroom needs of live music? I have read the crest 'how much amp power do I need?' webpage and it seems amps need to deal with huge dynamic peaks of 10-20db with live music.
Maybe compressors and limiters could reduce the dangers here.
I'm sure with some more knowledge I can at the very least put safe guards in place to avoid driver damage from amp overload causing clipping and driver over excursion.
I am a total novice throwing out buzzwords to sound knowledgeable.
But I have read a few things and these are the dangers I have read about.
I own a copy of Yamaha Sound Reinforcement book. That probably will answer all my questions.
1) Live music may have more dynamic range than the music you play back, but more dynamic range results in less average power used.
2) Most DJ and PA damage results from cooked voice coils rather than over excursion, wide dynamic range reduces average power, unless the amps are driven into clipping.
3) Yes, RMS and peak limiters can eliminate driver destruction and amplifier clipping if set properly.
Last edited:
What do you more knowledgeable guys think of my power amp calculations:
For my subwoofers (JBL 2245H) the continuous power rating is 600W at 8 Ohms.
The crown website has this advice:
How Much Amplifier Power | Crown Audio - Professional Power Amplifiers
The recommendations seem to be 2.5 times the continuous power rating of the speaker in amp power (watts). For loud heavy metal.
I am more a reggae sound system but I assume reggae is as demanding as hard rock for these calculation purposes.
So 2.5 times 600W is 1500W per driver.
I will have (16) 18 inch subwoofers in (4) quad boxes. If I buy crest 9001 amps. They deliver 2050W at 4 Ohms stereo. So If I have (2) drivers per channel I will get 1025W per driver. Which is 1.7 times the continuous power rating of 600W per speaker.
This would mean I would need (4) crest 9001 amps. One per quad.
If I am to follow the advice of the crown page I would need 1500W per driver. I am hoping having (16) subs should compensate for the lower amp power.
I am confused how an amp (like the crest 9001) can deliver 1100W 8 Ohms stereo which would be one JBL 2245H 8 Ohm speaker per amp channel. (2) speakers per amp.
But if I connect (2) speakers per channel, I get 2050W stereo at 4 Ohms so each speaker get's half of that power, 1025W.
In my mind this seems like in the first scenario I have two speakers getting a total of 2200W power at 8 Ohms from one crest 9001 amp. In the second example I have four speakers getting a total of 4100W at 4 Ohms.
To a laymen newbie it seems like connecting speaker in parallel reducing the impedance gives you extra free power. I assume it puts more pressure on the Amp though?
My friend put on a nice small/medium sized dance with (4) 18 inch subs getting 150W each. It didn't deliver chest thumping bass but he still got fined 500 bucks by noise control. It was bassy just not quite big reggae bassy.
1025W in comparison seems huge.
What are the most practical safety measures to prevent speaker damage from amp clipping. IOW, how to prevent amp clipping.
From my limited knowledge it seems that if you don't feed more than a line level to an amp then it won't clip.
Isn't that a simple requirement to implement. Just watch the meters from the mixer going to the crossover to amps.
I assume if I was doing live band through my relatively low powered sound system that I could keep the speakers safe by doing the same. Keeping the level to the amps below line level. And perhaps use compressors/limiters to reduce peaks that might overload the amps.
It frustrates me that I haven't read any simple explanation that satisfies me on how to keep all PA amps and speakers safe from damage.
Enlighten me brothers.
For my subwoofers (JBL 2245H) the continuous power rating is 600W at 8 Ohms.
The crown website has this advice:
How Much Amplifier Power | Crown Audio - Professional Power Amplifiers
The recommendations seem to be 2.5 times the continuous power rating of the speaker in amp power (watts). For loud heavy metal.
I am more a reggae sound system but I assume reggae is as demanding as hard rock for these calculation purposes.
So 2.5 times 600W is 1500W per driver.
I will have (16) 18 inch subwoofers in (4) quad boxes. If I buy crest 9001 amps. They deliver 2050W at 4 Ohms stereo. So If I have (2) drivers per channel I will get 1025W per driver. Which is 1.7 times the continuous power rating of 600W per speaker.
This would mean I would need (4) crest 9001 amps. One per quad.
If I am to follow the advice of the crown page I would need 1500W per driver. I am hoping having (16) subs should compensate for the lower amp power.
I am confused how an amp (like the crest 9001) can deliver 1100W 8 Ohms stereo which would be one JBL 2245H 8 Ohm speaker per amp channel. (2) speakers per amp.
But if I connect (2) speakers per channel, I get 2050W stereo at 4 Ohms so each speaker get's half of that power, 1025W.
In my mind this seems like in the first scenario I have two speakers getting a total of 2200W power at 8 Ohms from one crest 9001 amp. In the second example I have four speakers getting a total of 4100W at 4 Ohms.
To a laymen newbie it seems like connecting speaker in parallel reducing the impedance gives you extra free power. I assume it puts more pressure on the Amp though?
My friend put on a nice small/medium sized dance with (4) 18 inch subs getting 150W each. It didn't deliver chest thumping bass but he still got fined 500 bucks by noise control. It was bassy just not quite big reggae bassy.
1025W in comparison seems huge.
What are the most practical safety measures to prevent speaker damage from amp clipping. IOW, how to prevent amp clipping.
From my limited knowledge it seems that if you don't feed more than a line level to an amp then it won't clip.
Isn't that a simple requirement to implement. Just watch the meters from the mixer going to the crossover to amps.
I assume if I was doing live band through my relatively low powered sound system that I could keep the speakers safe by doing the same. Keeping the level to the amps below line level. And perhaps use compressors/limiters to reduce peaks that might overload the amps.
It frustrates me that I haven't read any simple explanation that satisfies me on how to keep all PA amps and speakers safe from damage.
Enlighten me brothers.
Roman,
What happened to those tube amp dreams?
Not to disparage Crest amps (I used them for over three decades), but the 9001 is not the most efficient use of power, though that's another discussion..
1) The JBL 2245H has a PE (Thermally-limited maximum electrical input power) of only 300 watts (as previously mentioned..)
If you use an arbitrary value of 2.5 x PE, you should be estimating 750 watts peak.
2)According to the specifications, the 9001 is capable of 161 volts peak output per channel, 6480 watts into 4 ohms. The old "boat anchor" Crest amps are fully capable of 2 ohm operation. Decades ago I ran Crest 5001 and 8001 (similar designs to the 9001) at two ohms, though their current limiting does reduce the maximum power per driver compared to 4 or 8 ohm operation.
3) The amount of subs does not "compensate" for amplifier power, but each doubling of drivers and cabinets does add 3 dB sensitivity.
4) Power amplifiers are actually voltage amplifiers- they deliver "X voltage" into "X load". If it were not for amplifier's (protective) voltage limiting, the power delivered would be exactly double for half the impedance.
The more power delivered, the more "work" the amplifier does - with no load there is no work, fine for solid state amps, not for tube (valve amps).
5) Each doubling of power is a 3 dB gain (less "power compression" from heating voice coils) so yes, 150 to 1025 is a "huge" difference, sounding around twice as loud.
6)Amp clipping does not cause speaker damage, too much average power causing voice coil burning or too much peak power causing mechanical damage are the two reasons for speaker damage.
That said, a clipped amplifier can put out more average power than it would otherwise.
7) The explanation is quite simple- keep the amps running cool (heat kills electrical components) and run the speakers within their thermal and mechanical limits.
Of course, to know the thermal and mechanical limits of a speaker requires an actual design to work with- the JBL 2245H PE of 300 watts is dependent on the impedance curve of the cabinet it is in, and it's mechanical limits will be reached at frequencies determined by the excursion curves..
Cheers,
Art
Attachments
I love reggae and enjoyed sessions in the open air. I sort of follow this thread, but I am a home hifi guy and can offer no technical advice. It's one of the reasons I don't reply andonly read half focused. But this quote activates me somehow.
You seem to know what sound and scale you need. I assume you also have a certain soundsystem experience you've had that you are after.
Low distortion amps and speaker systems all sound alike once dialled in, so that won't matter. More niche products with characteristic distortions (delay, frequency response peaks and dips, harmonic distortion) have a certain sound signature.
If you really, *really* want to approach the general regggae sound and/or a specific sound system's sound, you would get closest with basically the same set up. If they use scoops, then use scoops etc.
being a Karlson fan, I would suggest those for tuneful bass and good kick but they don't aesthetically fit in (a good grill would work) plus the slanted baffles might make rain catchers. A 15" size (33"x22.5"x18") K15 could be loaded with an 18, raising Lf cutoff a bit. Cetec-Gauss marketed an 18" K which was around 10.3 cubic foot. Big push pull tube amps build around EL509 or traditional "audio" tubes would give power.
some years back I bought a Yorkville UCS1 cabnet new - tested it outdoors vs an 8 cuibd foto Karlson type which really wasn't done as well as the old K15 from 1951. The 18" was an Eminence with qts ~0.25, fs ~30 and about 103g mms. That horn had 20dB more distortion than the K at 50Hz 50 watts
some years back I bought a Yorkville UCS1 cabnet new - tested it outdoors vs an 8 cuibd foto Karlson type which really wasn't done as well as the old K15 from 1951. The 18" was an Eminence with qts ~0.25, fs ~30 and about 103g mms. That horn had 20dB more distortion than the K at 50Hz 50 watts
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.