Help with DIY 4x10 needed

[Mr.T]

[quote name='Stewart' post='563251' date='Aug 8 2009, 01:19 AM']Placing multiple drivers vertically might be expected to extend the coverage vertically (ceiling to floor), but it actually greatly extends the coverage left to right.[/quote]

Can you help me to understand this concept?

I can see that having multiple drivers vertically would extend the coverage vertically, but not how having two rows of drivers (traditional 4x10 or 8x10) would then make that coverage horizontally narrower.... am I missing something?

[synaesthesia]

[quote name='lateralus462' post='563319' date='Aug 8 2009, 09:20 AM']So, you have twice as many people sat in the sweet spot, but it still isn't going to encompass the whole audience is it? not win win - maybe a slightly better solution but not the ultimate - now a cab wither side of the stage would be, but then again that would be a PA wouldn't it (but then again when using PA support where will the sound engineer sit the bass in the stereo mix? not dead centre I'm sure) To be honest I PREFER the sound of a 4 x 10 coupled with a 15 - not based on looks, based on SOUND seriously I am one of the least gear snobby people out there - I could not give a f**k whether my rig is 6' tall and 3" wide or the size of a shoebox as long as it sounds good.

- you assume that the bass sound from the amp is some way bad. Yes therre will be differences out front depending on where you stand, but I can't say I have been to a gig and thought, oh that bass sounds off - must be the dispersion of the cab, but I have been to plenty of gigs with bassists using 4 x 10's on there own and been impressed with the bass sound.[/quote]

All you are saying is you prefer a 4 X10, if that's the case play your bass rig through an original FENDER open backed 4X10 if there is no difference in cab design and no difference in audio dispersion. Restating and repeating personal reference is not a good enough rationale to base your arguments over design or acoustical science, --- some people prefer to vomit on their own clothes, it doesn't help in the science of personal hygiene. You are not helping the discussion on cab design.

For a band that does not rely on PA, dispersion from backline is important if you want to get your audio across; part of the problem is that many acts don't care for this - they prefer to have a roar of energy but acoustic dispersion or intelligibility is not important. For a band that relies on PA, dispersion across the stage from backline is important to a point if you aren't monitored otherwise. You will have had this experience at some stage, all you get in the wedges are vocals but you cannot hear the guitarist on stage clearly because guitar is not in the monitor mix, you cannot hear clearly despite the guitarist using a 4X12 as he/she is stage left of you....all you get is low end from the guitar. If your instruments are monitored in the wedges on stage, dispersion is less of a problem. If you and everyone else will use in ear monitoring and a good PA, dispersion is not crucial at all as you technically do not need a cab on stage.

[SteveO]

[quote name='alexclaber' post='562762' date='Aug 7 2009, 02:39 PM']Yes. Here: [url="http://www.billfitzmaurice.net/"]http://www.billfitzmaurice.net/[/url][/quote]

Personaly I have very little knowledge of how all this stuff works, I can only go on experience, and that is to say I have never heard a rig as good as one of Bills DR250's on top of one of his Tuba subs (with a SVT II head I think it was). Pretty light and seriously powerful. I think in that rig the DR250 had a single 10" and the Tuba had one 12" driver. Yes, I know that it sounds silly and that it should never match an 8x10, but however this folded horn malarky works, it works a treat. Just be aware that Bills designs are not just a box with the speaker mounted on the front, and it's not as simple as nailing 6 pieces of ply together. Saying that the plans are very good and take you through the building process in great detail, and they're cheap as chips.

[lateralus462]

[quote name='synaesthesia' post='563334' date='Aug 8 2009, 10:05 AM']All you are saying is you prefer a 4 X10, if that's the case play your bass rig through an original FENDER open backed 4X10 if there is no difference in cab design and no difference in audio dispersion. Restating and repeating personal reference is not a good enough rationale to base your arguments over design or acoustical science, --- some people prefer to vomit on their own clothes, it doesn't help in the science of personal hygiene. You are not helping the discussion on cab design.

For a band that does not rely on PA, dispersion from backline is important if you want to get your audio across; part of the problem is that many acts don't care for this - they prefer to have a roar of energy but acoustic dispersion or intelligibility is not important. For a band that relies on PA, dispersion across the stage from backline is important to a point if you aren't monitored otherwise. You will have had this experience at some stage, all you get in the wedges are vocals but you cannot hear the guitarist on stage clearly because guitar is not in the monitor mix, you cannot hear clearly despite the guitarist using a 4X12 as he/she is stage left of you....all you get is low end from the guitar. If your instruments are monitored in the wedges on stage, dispersion is less of a problem. If you and everyone else will use in ear monitoring and a good PA, dispersion is not crucial at all as you technically do not need a cab on stage.[/quote]

Yes i did say I preffer 4 x 10's - but that wasn't my main point - I was also trying to say that while a vertical array of 10's is scientifically the better option, in a PRACTICAL situation (ie a gig that is large/loud enough to require hefty backline support but not large enough to require PA support) it won't make that much difference - plus it only really becomes a valid point when you try to redesign the guitar amps to have an even dispersion as well (try getting a guitarist away from a 4 x 12!!! That's never going to happen) - and what do you end up with at the end of the day - the sound evenly dispersed equally left to right for each instrument across the whole field of the audience's hearing - surely that f***s up the whole stereo image of the band?

Edited August 8, 2009 by lateralus462

[SteveO]

[quote name='Mr.T' post='563332' date='Aug 8 2009, 11:01 AM']Can you help me to understand this concept?

I can see that having multiple drivers vertically would extend the coverage vertically, but not how having two rows of drivers (traditional 4x10 or 8x10) would then make that coverage horizontally narrower.... am I missing something?[/quote]

I think it's got something to do with interference paterns (like those double slit experiments we all did in science class at school) and because we have two ears, usualy aranged horizontaly. I also think it has something to do with the speakers being too close together - you don't seem to get those 'dead spots' from the PA speakers either side of the stage.

[Mr.T]

[quote name='SteveO' post='563349' date='Aug 8 2009, 10:22 AM']I think it's got something to do with interference paterns (like those double slit experiments we all did in science class at school) and because we have two ears, usualy aranged horizontaly. I also think it has something to do with the speakers being too close together - you don't seem to get those 'dead spots' from the PA speakers either side of the stage.[/quote]

Thanks,

Can someone elaborate?

[Mr. Foxen]

[quote name='Mr.T' post='563366' date='Aug 8 2009, 10:55 AM']Thanks,

Can someone elaborate?[/quote]
The double slit thing demonstrate interference, equivalent to haveing two speakers making the exact same sound a distance apart:


This bit I'm sort of questioning if it applies: I think that property of light as a wave where if you shine it through a slit it is a beam, but as you make that slit really narrow it spread out is also comparable, a single line of drivers being equivalent to a narrow slot:



Its all waves, and seems like super hard physics, but you can do it with sound and suddenly its all practical.

[Stewart]

[quote name='Mr.T' post='563332' date='Aug 8 2009, 10:01 AM']I can see that having multiple drivers vertically would extend the coverage vertically, but not how having two rows of drivers (traditional 4x10 or 8x10) would then make that coverage horizontally narrower.... am I missing something?[/quote]

Multiple vertical drivers don't extend the coverage vertically - they extend the coverage horizontally (where you want it) - it does seem counter-intuitive, I know...

Much of the effect is due to the (approximation of) creating a line source - like all those long hanging array PAs you invariably see these days.

This might help:

[url="http://www.linkwitzlab.com/frontiers.htm#E"]Line sources[/url]

[chris_b]

This is a very old argument. Maybe we should believe the theory that 410's shouldn't work, but in practice some work very well so base your purchases on your ears and experience.

I wouldn't make a 410 if you have back problems. I would use 2 210 cabs, stacked however you think sounds best, because they will sound as good as a 410 and they are a better solution to your lifting problem. Barefaced Compact cabs are a very good 115 alternative and will be even lighter.

[alexclaber]

[quote name='chris_b' post='563414' date='Aug 8 2009, 12:16 PM']This is a very old argument. Maybe we should believe the theory that 410's shouldn't work, but in practice some work very well so base your purchases on your ears and experience.[/quote]

Theory doesn't say that a 4x10" shouldn't work. It merely says that two 2x10"s stacked vertically works better. If you've only ever heard 4x10" cabs then you'd be none the wiser.

There is an argument to say that the poor off-axis response of 4x10"s actually helps to cover up the deficiencies of the speakers often used.

Alex

[Bill Fitzmaurice]

[quote name='Mr.T' post='563332' date='Aug 8 2009, 05:01 AM']Can you help me to understand this concept?

I can see that having multiple drivers vertically would extend the coverage vertically, but not how having two rows of drivers (traditional 4x10 or 8x10) would then make that coverage horizontally narrower.... am I missing something?[/quote]
You've made one of the most common mis-assumptions about how speakers work, which is that they radiate sound in the same fashion that light bulbs radiate light, ie., proportionally to their dimension. The opposite is the case. The wider the source the narrower the dispersion, the higher the source the less the dispersion on the vertical plane. This means that a vertical 4x10 also has half the vertical dispersion as a standard 4x10, which at first glance may seem counter-productive, but it's not. At the distance you're standing relative to the cab getting the upper drivers closer to your ear level still allows you to hear them much better than you can with them down low. At the same time farther away from the cab the narrowed vertical dispersion puts more sound into the audience, where you want it, and less into the floor and ceiling, where you don't. So not only does the vertical array give more uniform audience coverage, it's also louder within the audience for a given amplifier output.

[Dood]

[quote name='Stewart' post='563411' date='Aug 8 2009, 12:12 PM']This might help:

[url="http://www.linkwitzlab.com/frontiers.htm#E"]Line sources[/url][/quote]


Good grief! That's quite a site of info'. I need to go lay down!

[Mr.T]

[quote name='Bill Fitzmaurice' post='563465' date='Aug 8 2009, 01:51 PM']You've made one of the most common mis-assumptions about how speakers work, which is that they radiate sound in the same fashion that light bulbs radiate light, ie., proportionally to their dimension. The opposite is the case. The wider the source the narrower the dispersion, the higher the source the less the dispersion on the vertical plane. This means that a vertical 4x10 also has half the vertical dispersion as a standard 4x10, which at first glance may seem counter-productive, but it's not. At the distance you're standing relative to the cab getting the upper drivers closer to your ear level still allows you to hear them much better than you can with them down low. At the same time farther away from the cab the narrowed vertical dispersion puts more sound into the audience, where you want it, and less into the floor and ceiling, where you don't. So not only does the vertical array give more uniform audience coverage, it's also louder within the audience for a given amplifier output.[/quote]

Thanks for that.

These are concepts that I have never (had to) consider before.

So, in effect, my band mates would find it easier to hear a 4x10 column than a traditional 4x10.

Am I right in assuming (based on your comments about a wider source), that in general a 10" speaker in a 'traditional cabinet would have a wider dispersion than a 15" in the same style of cabinet?

[chris_b]

[quote name='alexclaber' post='563449' date='Aug 8 2009, 01:32 PM']....Theory doesn't say that a 4x10" shouldn't work. It merely says that two 2x10"s stacked vertically works better....[/quote]
Things can always be better or different but there are posts here saying that 410's don't work!

Compromises are always made in cab design and I'll accept that there are different shades of grey but I don't accept the argument that there is only black and white in cab design.

[Guest MoJo]

[quote name='Bill Fitzmaurice' post='563465' date='Aug 8 2009, 01:51 PM']You've made one of the most common mis-assumptions about how speakers work, which is that they radiate sound in the same fashion that light bulbs radiate light, ie., proportionally to their dimension. The opposite is the case. The wider the source the narrower the dispersion, the higher the source the less the dispersion on the vertical plane. This means that a vertical 4x10 also has half the vertical dispersion as a standard 4x10, which at first glance may seem counter-productive, but it's not. At the distance you're standing relative to the cab getting the upper drivers closer to your ear level still allows you to hear them much better than you can with them down low. At the same time farther away from the cab the narrowed vertical dispersion puts more sound into the audience, where you want it, and less into the floor and ceiling, where you don't. So not only does the vertical array give more uniform audience coverage, it's also louder within the audience for a given amplifier output.[/quote]

While I believe that what Bill is saying to be 100% true and that one of Alex's Compacts could probably knock my 4x10 into the middle of next week in terms of sound quality and dispersion, it is my honest opinion that two 2x10 cabinets stacked vertically look totally w**k when compared to a 4x10 (or two 4x10's). Sometimes what you take on stage with you isn't all about the sound, it's also about image, otherwise we'd all wear the same things on stage because it was the most practical or efficient clothing for performing in.

[ZMech]

this may be a stupid question, but would a single 2x10 (or 1x12 in my case) therefore have better dispersal if put vertical on an empty box at chest height, instead of sitting on the floor? and also, since my 112 has a tweeter, which way up is better? tweeter above or below?

sorry for the thread hijack

Edited August 8, 2009 by Zach

[Mr. Foxen]

[quote name='bassman2790' post='563495' date='Aug 8 2009, 02:31 PM']Sometimes what you take on stage with you isn't all about the sound, it's also about image[/quote]

Doom.

However, vertical arrayed speakers can look pretty awesome:

[Guest MoJo]

[quote name='Mr. Foxen' post='563501' date='Aug 8 2009, 02:42 PM']Doom.

However, vertical arrayed speakers can look pretty awesome:
[/quote]

However you've arranged two columns side by side, thus negating the dispersal advantages of a single vertical 4x10 as I understand it and they still don't look as cool as an 8x10 IMHO

[Mr. Foxen]

[quote name='bassman2790' post='563504' date='Aug 8 2009, 02:48 PM']However you've arranged two columns side by side, thus negating the dispersal advantages of a single vertical 4x10 as I understand it and they still don't look as cool as an 8x10 IMHO [/quote]

Depends if same signal is going in, and which are bass and which are guitar, and which are actually lights.

[Guest MoJo]

[quote name='Zach' post='563498' date='Aug 8 2009, 02:40 PM']this may be a stupid question, but would a single 2x10 (or 1x12 in my case) therefore have better dispersal if put vertical on an empty box at chest height, instead of sitting on the floor? and also, since my 112 has a tweeter, which way up is better? tweeter above or below?

sorry for the thread hijack [/quote]

From what we've learnt from the thread so far, it would seem that the practice of placing speaker cabinets on the floor is unadvisable unless you are on a raised stage which would bring the speakers in line with the audiences ears, so maybe a vertically arranged 2x10 on a stand is the answer. Bill ?

[Musky]

[quote name='Zach' post='563498' date='Aug 8 2009, 02:40 PM']this may be a stupid question, but would a single 2x10 (or 1x12 in my case) therefore have better dispersal if put vertical on an empty box at chest height, instead of sitting on the floor? and also, since my 112 has a tweeter, which way up is better? tweeter above or below?

sorry for the thread hijack [/quote]

It rather depends on what you'd call a better sound.

My understanding is that by having the speaker on the floor you'll get a 3db boost at the bottom end. By raising the speaker more to ear level you'll hear the upper mids and treble better. Best of both worlds would be to keep the cab on the floor but angle it upwards, although then the audience wouldn't be hearing the higher frequencies as well as you do.

[Mr. Foxen]

[quote name='Musky' post='563507' date='Aug 8 2009, 02:53 PM']It rather depends on what you'd call a better sound.

My understanding is that by having the speaker on the floor you'll get a 3db boost at the bottom end. By raising the speaker more to ear level you'll hear the upper mids and treble better. Best of both worlds would be to keep the cab on the floor but angle it upwards, although then the audience wouldn't be hearing the higher frequencies as well as you do.[/quote]

Depends on the floor, a flexible one will screw your sound.

[Protium]

[quote name='bassman2790' post='563495' date='Aug 8 2009, 02:31 PM']While I believe that what Bill is saying to be 100% true and that one of Alex's Compacts could probably knock my 4x10 into the middle of next week in terms of sound quality and dispersion,[/quote]

Until you get into a band situation with PA backing and then this whole argument becomes irrelevant

[Guest MoJo]

[quote name='Protium' post='563521' date='Aug 8 2009, 03:09 PM']Until you get into a band situation with PA backing and then this whole argument becomes irrelevant [/quote]

Both my bands have a full range PA, but I refuse to turn down to a level on stage that only a bat could hear so that I can be put through the PA and spend the whole evening just listening to the drums. As I said to the engineer, "If I'm too loud to go through the PA, don't put me through the PA...sorted"

[Bill Fitzmaurice]

[quote name='Zach' post='563498' date='Aug 8 2009, 09:40 AM']this may be a stupid question, but would a single 2x10 (or 1x12 in my case) therefore have better dispersal if put vertical on an empty box at chest height, instead of sitting on the floor?[/quote]Yes, though if the front of said box isn't a solid surface you'll lose coupling output above the frequency where the elevation is equal to 1/4 wavelength. With a 3 foot lift that's about 100 Hz. However, 'boom' also occurs in the vicinity of 100-180 Hz, so if you've got a boomy room elevating the cab can help tame it. [quote]and also, since my 112 has a tweeter, which way up is better? tweeter above or below?[/quote]
Tweeter above, as tweeters have narrower dispersion than woofers. [quote]it is my honest opinion that two 2x10 cabinets stacked vertically look totally w**k when compared to a 4x10[/quote]Don't think for one moment that the marketeers aren't well aware of your opinion. That's why cabs are made the way they are. If engineers ruled the roost, and didn't particularly care about the source of their next meal, the 4x10 would have gone the way of the Dodo twenty years ago, and with them all the other cabs with horizontally placed drivers. But even engineers have to eat, explaining why so many who do know better continue to build what the market demands, as opposed to what would best suit needs.