If I remember correctly, don't you have a truck load of T48's? What amps are you running to power those? Thanks.
Also, wouldn't the SPL of a particular speaker system be inversely proportional to the size of the room it was being played in? How do you correlate that for comparison purposes?
1) The SS15 rolls off below 60 Hz, 40 Hz is -10 dB. Between thermal compression, cone and cabinet flex, it will not reach the predicted 130 dB level, IIRC it was some 5 dB less at full power.
2) A 10 dB drop in level at 1000 Hz "sounds" half as loud. It takes almost 10 dB more level for 40 Hz to sound as loud as 1000 Hz.
Get a real SPL meter, the iPhone mic craps out around 110, and reads higher because the clipping adds level.
A 3 dB increase SPL requires double the power, 6 dB four times, 10 dB X 10.
3)Your tops will sound like hammered dog poo long before they reach the "one time only" peak of 132 dB.
4) It depends. An increase of only 5 dB at 20 Hz sounds twice as loud, LF extension can make a system sound louder without needing as much SPL.
I generally run around 90 dBA, and as much as 110 dBC at the mix location.
I use two Keystones (about 134 dB total, each driven with a bridged Crest CA9 around 3000 watts peak power), and the equivalent of about 10 of your tops, but I don't like to hear any distortion from the top cabinets.
5) Sound drops at 6 dB per doubling of distance, a room twice as large may take as much as 6 dB more SPL at the speaker end to sound as loud in the back. Because of the room boundary reflection reinforcement, it actually only takes about 3 dB more level, and large rooms support low bass better than small rooms, I have used the same amount of power in some little clubs as 75 x 150 foot halls.
Art
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120db at 1 meter in the bottom octave isn't terribly loud. Inverse distance law is -6db for doubling of distance.
One of Josh's 21" loaded big horns produces around 140db at one meter down to 35hz or so. Just to give you an idea. But it's BIG and will eat up all the power a crown macro tech 5002 has to offer. 😉
One of Josh's 21" loaded big horns produces around 140db at one meter down to 35hz or so. Just to give you an idea. But it's BIG and will eat up all the power a crown macro tech 5002 has to offer. 😉
Sorry a pair of the othorns hits 140db at one Meter. I knew I remembered the 140db figure...my mistake.
And they are 36x36x24 each.
And they are 36x36x24 each.
Wow - great answer!!!!! That explanation clears some things up for me that I think I had a misunderstanding of. Thank you Professor Art.
It seems like the more I learn, the more there is to know.
Pair of crown xti 4k. dont like them. saving pennies to pony up for itech 5000hds.
I dont have a truck load, because I dont have a truck 😀. i will stuff 5 of them in a minivan though.
also MRGSR, I believe it takes more like 3 or 4Othorns to hit 140db at 1 meter 40hz, with 100 volts in (reaches xmax at 19 and 38 hz with this voltage and a proper hipass as per the sim)
the brain and our ears is not so good at percieving bass. this chart helps explain that. 120 db at 4khz would likely hurt quite a lot. 120 db at 40 hz is probably just tickling your pants legs.
The un-amplified crowd hit 137db here
When building a soundsystem your goal is to have "enough rig for the gig".
For a rock band using a set of PA speakers like yours and a single 18" sub may be enough rig for small to medium sized bar, (say it can put out 125db@50 hz). For EDM music you would probably need a system capable of 130db @ 40HZ in the same venue (needing twice the subs and amp power). For club level you would need much much more.
Weddings are a whole other issue as the venue can vary in size and amount of people that show up will dictate how much rig you need. The human body absorbs sound and then tends to make a bunch more once alcohol is applied.
If it is outside trying to reproduce frequencies below 40hz takes lots of speaker power and you are better off concentrating on the frequencies above that unless you have a trailer full of subs.
Building speakers is fun and educational but if you are serious about the business aspect some clients (may) be uncomfortable with a DIY system, it has not happened to me but I am not soliciting that type of client. It sounds like you may be in a position to get into the trade so I would research the bizz over at DJforums, Prosound web, MobilBeat, ect.
Presentation and personality are huge in this field and I have seen many DJ's with atrocious sound systems captivate the crowd with a few lights and a audacious schtick, (wedding DJ's have justly earned this reputation)... You will eventually have to play the chicken dance.
Wow Mr. Doom, great examples!! That really is easy to understand and puts things in perspective for me.
My head is starting to spin with this new information. Thank you everyone for sharing your experiences. I am really glad I started this forum topic - I have learned so much from all of you. Thank you!!!!!!
By the way Mr. Doom, my brother is quite the showman with a very flamboyant personality. I bet he would be a natural for the "chicken dance."
My head is starting to spin with this new information. Thank you everyone for sharing your experiences. I am really glad I started this forum topic - I have learned so much from all of you. Thank you!!!!!!
By the way Mr. Doom, my brother is quite the showman with a very flamboyant personality. I bet he would be a natural for the "chicken dance."
Actually a single Othorn with a 5100 driver has been measured at 137dB at 31.5Hz and 139dB at 40Hz short term. Using the "peak" ratings lots of pro manufacturers like to quote adds 3dB to that putting actual measured "peak" output at 1m groundplane from a single cab at 140dB or more from 31.5Hz on up. Of course you need lots of power and this is at the ragged edge of the capabilities of the cab. It is much better from a standpoint of distortion, compression and longevity to operate it about 6dB below that.
To get back on topic...
OP you will probably get more concise and clear help if you define your situation as much as possible with details such as the maximum size of the cabs you would like, the shape wanted, how many cabs you wish to build, the available budget, which amplifiers are to be used, the application, etc...Some of which you have already stated, but a clean post with all of this information listed in one clear post would help.
As you have already found out the most cost effective way to get huge bass is a bass horn but these will often be huge and difficult to design/build and move. Bass reflex or bandpass cabs can be smaller and more easily transported but driver and amplifier costs are increased since the drivers don't recieve the force multiplication seen in a big horn. There are never any free lunches only tradeoffs everywhere. Good luck.
OP you will probably get more concise and clear help if you define your situation as much as possible with details such as the maximum size of the cabs you would like, the shape wanted, how many cabs you wish to build, the available budget, which amplifiers are to be used, the application, etc...Some of which you have already stated, but a clean post with all of this information listed in one clear post would help.
As you have already found out the most cost effective way to get huge bass is a bass horn but these will often be huge and difficult to design/build and move. Bass reflex or bandpass cabs can be smaller and more easily transported but driver and amplifier costs are increased since the drivers don't recieve the force multiplication seen in a big horn. There are never any free lunches only tradeoffs everywhere. Good luck.
Art, I have a question for you about your Keystones subs. My brother has read the forum post on that project. He wants to know that if he built that with a single LAB12, at half the width, would he also have to reduce the keystone cut-out to be half as wide. Thanks.
Well, we are still trying to figure out what exactly we want and need. The suggestions we have received so far have caused us to reconsider our original plans.
What we would like is two systems, as light/loud/small as possible that have serious low-end response. But as you mentioned above, that is not an easy or cheap accomplishment. My brother is really taking a liking to the cabinet building, so we may just a few different styles of cabs and see what works best for us. The first cab he built turned out very professional looking, and he thinks he can easily sell what ever he builds that doesn't work out fro us.
We are very new to this whole thing, so all the suggestions we have gotten have really helped us learn and narrow in on what we want/need. So anyone else who is reading this and wants to toss an opinion out, please do. Thanks.
Remember you only get to pick 2 out of loud low and small. you seem to want something loud low and small.
We are trying to figure out what the ideal balance of those three elements are. I see that we are going to probably have to compromise on all three of those elements, so we need to figure out what the best solution will be.
I have another question for your though. With you Titan48's, you probably have to high-pass at 35-40hz. I think you mentioned once you do a lot of bigger EDM shows. Do you feel you are missing something doing that type of music and not being able and not getting the super low-end down around 30hz?
We have realized the hard way that we definitely need at least solid 40hz response. I am really wondering if we really need to attempt to get something down at the 30-35hz range, or will it be to hard to achieve with our limitations?
Thanks for your help.
Truth, but it may not fall into *light* at that point (given that many the highoutput drivers are heavy even in neo flavor) . but then again small is quiet subjective. g
The way im reading the reqs, is he wants one of your sw115 loaded keystones, in the size of one of your dual lab 12 ported enclosures that weighs no more than 60lbs. And my guess is there is no budget for a 18sw115 (considering he needs 2 seperate setups and amps to boot).
I hipass at 35. i do basically the most excrutiatingly rigorous form of music in the lf department (uk deep dubstep). 1 in 10 songs are lackluster on the system due to strong 28-38 content, but i generally haul twice as much gear as a sane person would (i limit myself to 400 person rooms with the full rig) due to the spl reqs in the bass dept, which keeps the mouth area of the system high, and keeps me from pushing the anemic xti 4ks to hard.
This track is still a let down on 6 t48 (maybe with itechs it would be passable), and unfortunatly is one of my favorites. sounds GREAT on 8 lab subs with macrotechs on 30 amp breakers though, so i know i need to look into a design that will get me a BIT lower but i cant afford the doubling in size a labhorn would entail (this is where the 18sw115 steps in)
V.I.V.E.K - Asteroids - YouTube
The way im reading the reqs, is he wants one of your sw115 loaded keystones, in the size of one of your dual lab 12 ported enclosures that weighs no more than 60lbs. And my guess is there is no budget for a 18sw115 (considering he needs 2 seperate setups and amps to boot).
I hipass at 35. i do basically the most excrutiatingly rigorous form of music in the lf department (uk deep dubstep). 1 in 10 songs are lackluster on the system due to strong 28-38 content, but i generally haul twice as much gear as a sane person would (i limit myself to 400 person rooms with the full rig) due to the spl reqs in the bass dept, which keeps the mouth area of the system high, and keeps me from pushing the anemic xti 4ks to hard.
This track is still a let down on 6 t48 (maybe with itechs it would be passable), and unfortunatly is one of my favorites. sounds GREAT on 8 lab subs with macrotechs on 30 amp breakers though, so i know i need to look into a design that will get me a BIT lower but i cant afford the doubling in size a labhorn would entail (this is where the 18sw115 steps in)
V.I.V.E.K - Asteroids - YouTube
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Have you reviewed my thread? Because I had very similar design goals.
- Transportable in a sedan, wagon or small SUV, and compatible with stairs.
Entire system is around 300 lbs or so. Pair of 55 lb subs, pair of 40-50 lb 4U rack cases, 32 lb tops, cable/cord bag, tool/setup/misc bag and laptop. No casters, everything can go up stairs or a hill or across rough terrain with one person. Subs are 4 cubes gross, 16x20x22". Stored easily when not in use.
- Solid bass response to handle modern EDM/pop dance music.
Subs are tuned to 35hz, and give good response to 30hz indoors. 8th order highpass around 26hz, low pass 4th order around 180hz. Subs naturally have a rising bass response to a peak around 40 hz. Provides LOUD low bass presence without being boomy, enough to seriously vibrate any house indoors, loud at 30 ft outdoors. Plenty of kick due to the highish high pass and the good phase response of a BR design at crossover to the mains.
- Hi-fi sound quality, (far) beyond that of a normal PA system.
Tops are peavy impulse 100's, heavily modified with bracing and damping to reduce distortion, the stock drivers are actually very good. Tops are all analog chain (eq/crossover, amp) after the DAC. Very clean and clear. Subs are an optimized ported design, 1/2" ply, internal damping, large slot port, with a bracing design to optimize air flow and minimize compression at high output, for a very clean bass sound overall. People who hear the system have been exceptionally impressed with the clean sound, to the point where this has been specifically mentioned to me several times.
- Loud enough output.
I've measured (basic spl meter) the system with music at 110db with peaks to 114db in a 600 sqft room at about 80% output. Subs sim around 125 db peak @ 1m.
- Reasonable power requirements.
Has run off a 2000w honda generator outdoors, and indoors on a single 15a breaker, though 20a is preferred. All long power cabling is 12g: 50ft cord and 20a (plug switched to 15a) rack power strip. Will try putting the sub amp on it's own breaker if I get a chance, should make an incremental improvement. Its amazing that a large class A/B amp and large class d sub amp can run off one breaker.
- Reasonable cost for an amateur stereo project.
Overall, I'm into the system for about $2000 and 200 hours of labor, plus about $500 of electronics I already had. Parts and materials for the subs including amp is about $1000. This is my own recreational system for house party use, etc, that will come out about a half dozen times a year over the next 5-10 years.
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Yours didn't happen to sound anything like the one in this video did it?
Bill Fitzmaurice Titan 39 with Lab 12 driver - YouTube
Because this video in particular is a prime example of what it sounds like (and how the voltage appears through a multimeter) when you've got the frequencies for the high pass filter and low pass filters set the polar opposite of what they should be.
Comparatively, a 10" loaded T39 should sound more like this:
BFM T-39 16" wide - YouTube
Not that I would've recommended going with the T39 to begin with for DJ'ing. Stepping down another notch from ~40HZ to ~30Hz is a BIG deal sound-wise.
Granted, until you experience the difference for yourself under controlled conditions in realistic applications, you really can't really get too upset for not knowing beforehand.
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