[FAQ]Speaker building

[burdizzos]

The Burdizzos Mod


This mod was originally done on an Avatar B212. I swapped out the horn for a Galaxy Audio 5" driver. I have since used Galaxy's new Neo 5" driver and I think it sounds better than the standard driver. It has a claimed range of 150 to 18,000Hz and a claimed power handling of 100 watts RMS. If a crossover set at 500 Hz is used, it fills out the high frequency sound of the bass without being harsh, as horns often are.

http://img70.imageshack.us/img70/7910/trickedoutavatar.jpg

This can be done in any cab where there is room on the front baffle to fit the new speaker. It has a 4.75” square footprint and the mounting holes are 3.33” apart on the sides. It takes up slightly more space than a standard horn.

In the case of the Avatar, the horn hole had to be opened up a little bit to allow the Galaxy to fit. I used a jigsaw for this and it took about a minute.

Here are the links to the parts for this mod:


Galaxy 5" Driver. (http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-020)

Emience Crossover (http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-630)


I had a problem with an Eminence crossover, so I am no longer using those. I built a simple 12 dB slope 2nd order crossover using one inductor and one capacitor. The eminence crossovers work well and they require very little effort to install, but the low pass coil will soak up a little bit of power.

Here are the links for the 2nd order crossover:

Inductor (http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=266-918)

Capacitor (http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=027-440)


Here's a picture of how the crossover should be wired up:


http://www.colomar.com/Shavano/spk12db1.gif


When using the home made crossover, there is no low pass filter. The wires are connected directly to the Low Frequency driver and the crossover and High Frequency driver are connected in parallel.



This does NOT alter the speaker cabinet's impedance. If a crossover is used, the amplifier will only "see" the load presented to it by the LF drivers.

[J.]

Here's a little spiel I wrote in another thread regarding the Avatar horn modification. It could be applied to speaker building (mostly crossover use) in general as well:

The 'Avatar horn mod' many people speak of is simply adding an appropriate high pass filter to the horn. The "crossover" that comes stock with the Avatar cabs is simply a capacitor wired inline with the foster horn, providing a 6db per octave rolloff below the crossover point (which is 3500hz if I remember correctly). Simply stated, this slope isn't steep enough to give proper protection to the horn, resulting in 'harshness' as the horn tries to produce frequencies that are at (and below) it's lower limits. With the simple capacitor acting as the HPF, the horn is only down 6db at 1725hz and is still getting a fair amount of power.

In order to get better performance, reliability, and sound from the horn, a better HPF with a steeper slope is needed. I think something along the lines of a 3rd order (18db/oct) or 4th order (24db/oct) would suffice. If you do a search on talkbass.com you'll see that a lot of folks there have made their own linkwitz-reilly 24db/oct high pass filters for their Avatar cabs and significantly improved the performance. In fact many even lowered the crossover point to 3000hz with good results - you can do this because with such a steep rolloff you're still going to have much, much less power going to the horn at 1725hz with a 3000hz 4th order than you would with a 3500hz 1st order.

If you're not up to building your own high pass filter, I'd suggest installing this one from Eminence:
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-602

It's a 18/db per octave HPF with built-in bulb protection. Replacing the existing cap with this crossover with definitely improve the horn's performance and reduce harshness.

[J.]

This little page rules all when you need to design your own crossover. You plug in the impedance if your drivers, the frequencies you want and the type of crossover, and it'll give you a little diagram with the values for the components included.

http://www.lalena.com/audio/calculator/xover/

[burdizzos]

Actually, Dave is now putting real 12 dB slope crossovers in his cabs.

http://www.avatarspeakers.com/pictures/newinput2.jpg


Good on him, he made a great cab better and didn't jack up the prices.

[zenfascist]

A few questions:

1. Where can I download winISP?
2. Would it be possible to convert an Avatar 115 into a 118? It looks like there's room in the enclosure to where I could just make the hole bigger.

http://www.avatarspeakers.com/pictures/b115h%20kappa.jpg

[burdizzos]

WinISD

To download WinISD,
click here. (http://www.linearteam.dk/default.aspx?download=winisd)


There are a couple of important things to know about WinISD.

First, the database that comes with it isn't accurate. You will need to upload specs to get the best results.

Second, ISD is not perfect. It is a free program that, in my experience, performs almost as well as box building programs that you have to pay for. In the speaker cab building game, approximations are almost always close enough.

The Help menu is very good, but I’ll go through the stuff anyway because I might have some stuff to add that may not make sense otherwise.




Click the “New” button at the top of the screen.

A window will open. Click the “new” button to the right of the Driver Name bar.

This will open the Driver Editor window which allows you to manually load the various driver specs.

These specs are available though most manufacturers’ websites. Part Express usually lists the driver specs with pdf files of the driver brochures.

There will be a discussion about what each of these things means in another post.

Make sure that you get the units right on each of these. The units can be changed to suit the specs that you have by simply clicking on the unit.

Once you have entered the driver data, hit the “OK” button and all of the specs should turn from black to gray. This indicates that the driver data has been saved.

Then you can click the “Close” button and the Driver Editor will close.

To use this new data, click on the “New” button again and select “Own drivers”. Your driver should appear in the drop down bar. Select the driver you wish to use and click “Next”.

Then you will be able to select the number of drivers that you wish to use in your enclosure and whether you want them to be loaded in a standard fashion or with an isobaric configuration. I’ll explain Isobaric later.

Next you will be able to choose whether you want a seal, vented (ported), 4th order or 6th order bandpass enclosure. Most bass cabs will be standard ported cabs, but feel free to tinker around with the other options. Make your selection and then click “Next”.

A new window will open with your driver’s information and a computer generated ideal box. WinISD gets this “ideal” box wrong as often as it gets it right. It will also display a gain curve in the Plot Window. The red line is the 0 dB point as defined by the driver’s sensitivity. The purple line indicates -3 dB. The default graph color is green, but that can be changed by clicking on the colored bar at the bottom of the Driver window.

From the “Box” tab you will be able to alter the cab’s internal volume and tuning frequency. With each change made, the graph will change to represent the frequency response of the enclosure.

Within the Box tab, there is a “Box Shape” button. By clicking this, another window will open that will allow you to enter box dimensions. Enter the board thickness first and then enter two of the three inner dimensions. After two of the dimensions are entered, you can move your cursor over the letter of the third dimension and click. This will calculate what the third dimension will be given the first two, the board thickness and the cab volume. Hitting the “OK” button, closes this window.

From the “Vents” tab, you can alter the size shape and number of ports to be used in your cab.

For most of the cab designing process, you’ll be using the box tab and trying to find a good compromise between low end response and cab portability.

Ideally, you’d want a cab that can play the fundamental of what you are playing. For a 5 string with a low B, that is 30 Hz or so. This is nearly impossible with a reasonably sized cab and an efficient speaker.

Realistically, a cab that will have a -3 dB point of 40 Hz will be a great sounding cab and offers a good balance between performance and portability.

Even a cab with a -3 dB point of 50 Hz will sound fine. Keep in mind that an Ampeg SVT has a -3 dB point of 58 Hz and it has been a benchmark of what a bass cab should sound like for years. So, a -3 dB point of 60 Hz really isn’t bad at all.

[Crescent Seven]

When you're sizing your ports, what does the " Qes/Pe! "
signify? I feel like since it's in red with an exclamation point, it's telling me I'm screwing something up...
C7

[burdizzos]

That implies that the port is far too short and you haven't entered a vallid value for the port diameter or size.

When the Vent Match number is red, I think it is telling you that the port is too small and could result in port noise.

The bigger the port, the better, in my opinion.

[burdizzos]

There's no advantage to putting an 18 in the Avatar B115 cab. It won't play any lower and it will probably be boomy.

[bpocall]

Hey burdizzos, where would I find the Pe and Z on Eminence's site? Also, which SPL do you go with on their sensitivity charts? Thanks.

[Crescent Seven]

Originally posted by burdizzos
That implies that the port is far too short and you haven't entered a vallid value for the port diameter or size.

When the Vent Match number is red, I think it is telling you that the port is too small and could result in port noise.

The bigger the port, the better, in my opinion.

The problem I have is, there are times where I can't get it to NOT be red. I can tinker with all kinds of numbers and it doesn't change...
C7

[J.]

Originally posted by burdizzos
Actually, Dave is now putting real 12 dB slope crossovers in his cabs.

Yeah, I saw that recently. Very good on him. It's still not as good as a third or fourth order in my opinion (at least on a compression horn), but definitely a step above the first order he was using.

[SeanTheBear]

Anyone know where I can get 2x15 or 4x12 sidewinders for bass/guitar cabs? I have a 79' Marshall bass 2x15 I'd like to put in there and a 2x12 fender cab I'd like to put in there for guitar.

[Crescent Seven]

Could somebody post a set of diagrams describing what the different orders of crossovers are, and what their uses are?
C7

[Emprov]

Originally posted by Crescent Seven
Could somebody post a set of diagrams describing what the different orders of crossovers are, and what their uses are?
C7
Look here... (http://www.partsexpress.com/resources/crossover/xoverfaqs.html)

and here (http://www.partsexpress.com/resources/crossover/xoverhelp.html)...

here... (http://www.partsexpress.com/resources/crossover/xoverhelp.html)

and here. (http://www.partsexpress.com/projectshowcase/xover/xover.html)

Just an elementary primer but it's a darn good start.

[burdizzos]

Originally posted by bpocall
Hey burdizzos, where would I find the Pe and Z on Eminence's site? Also, which SPL do you go with on their sensitivity charts? Thanks.

Pe is the RMS Power rating, in watts, of a speaker.

Z is the rated impedance, for most eminence drivers, it is 8 ohms.

Sensitivity is a tricky thing. Ideally, you'd like to get the speaker's sensitivity at or below 100 Hz, but that information usually isn't available. So, you just have to go with what you're given and consider the source as a means to remain objective when comparing drivers.

When it comes to Eminence, I'd recommend using the sensitivity at the lowest frequency available, which is 200 Hz. You could also print out the response graph for the speaker and use a ruler to determine the sensitivity at 100 Hz.

Always look at a response graphs if they are available. This will give you a better idea of how the speaker will work in the 40 Hz and below area. If a speaker is 97 dB at 1000Hz, but only 89 at 100 Hz, you might want to look elsewhere.

[burdizzos]

Thiele-Small Parameters (http://www.eminence.com/resources_data.asp)

[burdizzos]

Let's talk construction.


Where are the woodworking folks who can explain why a dado is better than a butt joint?

[Gruven]

There is, slightly, more gluing surface and additional strength with dado joints, but they have to be cut cleanly or the gluing surface is diminished. The dado joint traps the wood in place. This joint is useful when isolating one speaker from another, in the same box.

[takeout]

Originally posted by burdizzos
Let's talk construction.

Where are the woodworking folks who can explain why a dado is better than a butt joint? Bruce Zinky explains why he uses Baltic Birch and rabbet/dado construction. (http://www.zinky.com/construction.html)

[burdizzos]

Here's a neat Cab building link for "Best Little Bass Speaker Cabinet" (http://www.billsbest.com/thbasscab.html)


And a link to the Len Moskowitz article about building a compact bass cab. (http://www.core-sound.com//bottom-article.html)

The Len Moskowitz article is a great read for anyone trying to understand speaker cabs and why things are the way they are.

[burdizzos]

Neodymiun Discussion

In another thread we were discussing the differences between an Avatar B212 loaded with Delta LFs and one loaded with Deltalite 12s.

Originally posted by bassman1956
Here's stats as they're posted on the Parts Express page, for a 12" Delta LF and a 12" Deltalite. From these, aside from the very obvious weight differences, it's looks to me like the neos would even be better on the low ends. But it seems you're saying that's not so. Care to expound?


EMINENCE DELTALITE 2512 12" NEODYMIUM DRIVER

Magnet weight: 7 oz.
Shipping Weight: 8lb. 6 oz.
Resonance:42Hz
Usable Frequency Range: 30Hz - 3.5kHz
Sensitivity @200Hz: 97 dB


EMINENCE DELTA-12LFA 12" LOW FREQUENCY DRIVER

Magnet weight: 56 oz.
Shipping Weight: 13lb. 6 oz.
Fs: 45 Hz
Frequency range: 45-3,000 Hz
Sensitivity @200Hz: 94.5 dB


To which I replied:

Those specs don't even tell half of the story.

The most important part about how a speaker sounds is the cabinet that is used.

Since we are talking about an Avatar B212 cab that is roughly 5 cubic feet and is tuned to 50 Hz. In that cab the speaker with the lower Vas will work better.

Delta 12 LF Vas: 2.4 cu. ft.

Deltalite 2512 Vas: 5.46 cu. ft.

If you put a single Deltalite 12 in the B212 sized cab, it will have a similar response to the same cab loaded with two 12 LFs. It will also be just as loud since the Deltalites are 3 dB more efficient than the LFs. However, it won't handle as much power and it won't move as much air, so at 50 paces and 500 watts, the 2x12 LF configuration will be louder.

My 1x12 Neo cab is 3.7 cubic feet and my 2x12 Delta LF cab is about 8 cubic feet. At close range, they are almost equally loud, but at the other side of a 400 sq ft room, there is an audible difference. Teh big difference is that the LF cab is the right size for those drivers, it plays flat to 40 Hz and plays the B string with authority. The Deltalite is in too small of a cab, so it's low end response isn't nearly as good.


The Avatar B212 is way too small for two Deltalite 2512s, but I think Dave got some kind of special brew neo speakers for his cabs that I think have a higher Xmax, but based on his description of the the difference in sound, I'd say that they are very similar to standard 2512s in sound.




The bottom line:

The Delta 12 LFs will play lower and handle more power in an Avatar B212. It will also be 10 pound heavier and probably take more abuse.

The Neo B212 will be 3 dB more efficient and have a fantastic upper mid response which yields a better tone and a less forgiving cab(your mistakes will be more apparent). The tradeoff is a loss of low end. If you play a 5 string, the low B will lack authority whith this cab and the EQ will only be able to do so much given the power handling of the Neo speakers.



Here's another difference that may or may not be worth anything, but it is interesting.

The temperature thing that is discussed about Neodymium is the Curie Point.

The Curie point, or Curie temperature of a ferromagnetic material, is the temperature above which it loses its characteristic ferromagnetic ability to possess a net (spontaneous) magnetization in the absence of an external magnetic field. - Borrowed from Wikipedia

The Curie point of Ferrite is 450 °C(842F)

Neodymium: 319 °C(606F)

Copper doesn't melt until over 1000 °C.


So I suppose it is easier to destroy a neodymium magnet with long hours of playing than its ferrite counterpart. The Eminence Deltalite drivers have cast aluminum frames that go right up to the magnets assembly which has a cast aluminum heat sink on it, so it would seem that the neo drivers have better heat dissipating qualities anyway.

[Emprov]

Originally posted by burdizzos
Let's talk construction.


Where are the woodworking folks who can explain why a dado is better than a butt joint?

It's a heck of a lot easier to square a dado joint than a butt joint. Also there's more exposed wood allowing a more secure glue joint. Dovetails are ideal IMO but I don't have a dovetail jig.

[Gruven]

Originally posted by Emprov


It's a heck of a lot easier to square a dado joint than a butt joint. Also there's more exposed wood allowing a more secure glue joint. Dovetails are ideal IMO but I don't have a dovetail jig.
Dovetails aren't a good choice for plywood. Solid wood, yes. Plywood feathers and delaminates sometimes.

[Emprov]

Originally posted by Gruven

Dovetails aren't a good choice for plywood. Solid wood, yes. Plywood feathers and delaminates sometimes.

With higher grade plys I've never had a problem with them. I'd never do it on cheaper stuff but, if we're talking voidless birch, I'd do it every time if I had the jig.

[Crescent Seven]

Originally posted by Emprov


With higher grade plys I've never had a problem with them. I'd never do it on cheaper stuff but, if we're talking voidless birch, I'd do it every time if I had the jig.

$$$$. I was tempted to use OSX again on this 1x15 box, but I went with 3/4" Fir Ply instead. $30 a sheet.
The next box is going to be higher grade ply, I dont like this stuff I'm using right now.
C7

[burdizzos]

Speaker Building Material Sources



Parts Express (http://www.partsexpress.com)

PE is my favorite and they ship worldwide.




US Speaker (http://www.usspeaker.com/)





Does anyone have a link to an expanded metal supplier?

[Crescent Seven]

Originally posted by burdizzos
Speaker Building Material Sources

Parts Express (http://www.partsexpress.com)

PE is my favorite and they ship worldwide.

US Speaker (http://www.usspeaker.com/)

Does anyone have a link to an expanded metal supplier?

Does PE do better than US Speaker on shipping? It cost me $13 to ship $4 worth of plastic parts that weighed less than 1/2 lb.:rolleyes:

Also, I'm looking for and expanded steel source locally; if I find one and they ship I'll post it. There's a place right down the street from me that might have it but I have to take a day off to go in there because they close at 4pm:mad:
C7

[takeout]

Originally posted by burdizzos
...[DeltaLite vs. Delta LF discussion]...Let me ask you this: how would you feel about two DL's, each in their own box (bigger than the one you built, say roughly the size of the average 4x10)? Loud/low enough for just about any app?

[burdizzos]

Originally posted by takeout
Let me ask you this: how would you feel about two DL's, each in their own box (bigger than the one you built, say roughly the size of the average 4x10)? Loud/low enough for just about any app?

Yeah, I'd think so.

You'd be getting an honest 100 dB sensitivity at 55 Hz and up with a -3 dB point between 40 Hz(6 ft^3 boxes) and 47 Hz(4 ft^3 boxes).

That really isn't a bad idea at all.

If you need much more rig than that, you should be investing in a PA anyway.

[takeout]

I'm trying to decide on speaker purchasing right now. I was all set to buy a couple of DLs, until I got to thinking about those Selenium 12s. I could build a really nice 3ft^3 box for one of those...

[burdizzos]

Unles you're going to try to build some kind of ultralight box, I'd go with the Seleniums.

I'm considering a 1x12 with one of those to compliment my DL cab.

[zenfascist]

My 2x15 isn't ported and it's farting. It has brand new speakers. Would it benefit from being ported, and if so, how should I go about doing so?

[Crescent Seven]

Here's an interesting question: If I'm building two cabs to compliment one another, is there a way to custom match the boxes in terms of sound and response?
C7

[burdizzos]

Originally posted by zenfascist
My 2x15 isn't ported and it's farting. It has brand new speakers. Would it benefit from being ported, and if so, how should I go about doing so?

If it's farting because the speakers are bottoming out or overextending, porting will only make the problem worse.


Right now the air pressure in the cab is trying hold the speakers in place against the force of the motor. If the cab is ported, that pressure will no longer exist and the speakers will be able to move more freely.


I'd suggest that you figure out where the distortion is coming from before doing anything.

What sort of speakers are they?

[burdizzos]

Originally posted by Crescent Seven
Here's an interesting question: If I'm building two cabs to compliment one another, is there a way to custom match the boxes in terms of sound and response?
C7


You can use ISD to see what the response of the two cabs would beand see where the overlap is. Assuming the cab efficiencies are matched(see below), you will get a 3 dB increase in the range where the two cabs' responses overlap.

You can also use the speaker sensitivities to determine the correct number of drivers for each enclosure.

Suppose you build a 1x15 cab for a Peavey Scorpion and then want to add a 2x10 loaded with Eminence Deltas to compliment it. The Peavey is a very efficient driver(99dB) and will be very loud on its own. The Delta 10 is only 95 dB, so you will need to have a cab loaded with two Deltas to match the level of the Scorpion.

[burdizzos]

Thanks for the questions, guys. You just reminded me that I need to do a sealed versus ported discussion and a bit about dB increases with both additional speakers and additional watts.




Sealed Versus Ported (http://diyaudiocorner.tripod.com/dilemma.htm)


This is far better than I could do and really gets into more information than most people want, but it's worth reading nonetheless.

There is a chart near the bottom of the page with the pros and cons of each design.

[burdizzos]

Increasing Power


The equation for the decibel increase for an increase in power is

10 * log(p1/p2)

Where P1 and P2 represent the power values.

For instance, if I want to calculate the volume difference that I'll get when I go from 100 watts to 200 watts, it would look like this:

10 * log(200/100) = 3.01

When you double power, you get a 3 dB increase in volume.

3 dB is an apparent increase, but to double the perceived output, there must be a 6 to 10 dB increase.

To get 10 dB, you'd need to increase the power by a factor of ten.

10 * log(1000/100) = 10

[burdizzos]

Adding Speakers


Every time you double the number of drivers that you have, you will increase the output by 3 dB.

So, if you have an Aguilar GS112 and you believe their specs, you'll have a cab that is 102 dB sensitive.

If you add another one, you'll get up to 105 dB.

Add two more and you're up to 108 dB.

[burdizzos]

So, if you have your 4 Aguilar GS112s and an Eden WT405, here's what you'd get.

1 GS112 with the WT405(250 Watts at 8 ohms) would result in doubling the power over the rated 1 Watt, 8 times. Given that there is a 3 dB increase every time you double power, you'd get a 24 dB increase over the rated 102 dB, resulting in an output of 126 dB.

2 GS112s would get you another 3 dB, resulting in 129 dB.

4 GS112s would gain another 3 dB still, resulting in a 132 dB output.



On the other hand, you could just go with a bigger amp.

Same cabs with a Genz Benz GBE1200.

1 GS112 and a GBE1200(550 watts at 8 ohms) would result in a 27 dB increase over the 1w/1m rating of 102 dB, resulting in 129 dB.

2 GS112s, 132 dB
4 GS112s, 135 dB

[zenfascist]

They're Eminence Delta speakers.

[burdizzos]

Originally posted by zenfascist
They're Eminence Delta speakers.


Damn, those are 400 Watt RMS speakers, they should not be breaking up in a sealed box.


What are you driving them with?

[Gruven]

Originally posted by burdizzos



Damn, those are 400 Watt RMS speakers, they should not be breaking up in a sealed box.


What are you driving them with?
An article that I read says that sealed boxes cause the speakers to break up at high volumes and that ported cabinets always sound cleaner.

[burdizzos]

There are no hard and fast rules on that.

Typically, sealed boxes handle more power. However in a sealed box the speaker can be at its maximum travel at resonant frequency which will produce distortion.


Ported enclosures, on the other hand, have a sort of built in protection for the speaker at the tuned frequency. The trouble is that as the input goes below the tuned frequency, the driver is uncontrolled and can suffer severe damage.


Still, I'm curious where the distortion is coming from.

[zenfascist]

It's not even distortion, it's that they're just, well...farting. It sounds like they're bottoming out, even with the bass turned down pretty low. The cabinet was built in the 60s or 70s, so maybe it's just constructed poorly. I'm driving them with a Traynor YBA 200 (200 tube watts). Should I just trade it in for something better, or would it be worth trying to fix? What sort of problems should I look for?

Thanks for all your help, burdizzos. :thu:

[burdizzos]

Originally posted by zenfascist
It's not even distortion, it's that they're just, well...farting. It sounds like they're bottoming out, even with the bass turned down pretty low. The cabinet was built in the 60s or 70s, so maybe it's just constructed poorly. I'm driving them with a Traynor YBA 200 (200 tube watts). Should I just trade it in for something better, or would it be worth trying to fix? What sort of problems should I look for?

Thanks for all your help, burdizzos. :thu:


It could be a crap cab that is just too damned small for those speakers. They could very well be bottoming out.

Also, the resonant frequency of that speaker is 40 Hz. I'll bet it farts the worst with an open E string.


Do you feel like building a cab? I could give you the specs later this afternoon.

[zenfascist]

Originally posted by burdizzos



It could be a crap cab that is just too damned small for those speakers. They could very well be bottoming out.

Also, the resonant frequency of that speaker is 40 Hz. I'll bet it farts the worst with an open E string.


Do you feel like building a cab? I could give you the specs later this afternoon.

Haha, yep, it farts on open E. Building a cab sounds like lots of fun! And I'm sure it would be cheaper and easier than a trade-in or something. I'll PM you my email or you could post the specs. Thanks again bud. :)

[Crescent Seven]

Originally posted by zenfascist


Haha, yep, it farts on open E. Building a cab sounds like lots of fun! And I'm sure it would be cheaper and easier than a trade-in or something. I'll PM you my email or you could post the specs. Thanks again bud. :)

It is alot of fun. As long as you have the speakers, it's definitely cheaper to build it yourself, and you get a custom box...if you're interested, I have a place here in Denver that sells vinyl for $7 a yard, several colors, including black; I just covered mine with it and it came out awesome.

By the way Burdizzos, I finished that cab! Sounds great. I'll post pics tonight, hopefully.
C7

[mlwarriner]

any idea what the specs are on the speakers in a peavey 412tvx? i wonder about building a custom cab to load with the speakers out of the peavey, more because i'm a tinkerer than anything else...



please and thanks!

[Crescent Seven]

Originally posted by mlwarriner
any idea what the specs are on the speakers in a peavey 412tvx? i wonder about building a custom cab to load with the speakers out of the peavey, more because i'm a tinkerer than anything else...



please and thanks!

Pull one out and see what model they are. Peavey has the parameters on their website.
C7

[Markee]

Hey Zen, try reversing the wires on the speaker. Check with a nine volt battery to make sure your speakers push out instead of suck in.

[mlwarriner]

Originally posted by Crescent Seven


Pull one out and see what model they are. Peavey has the parameters on their website.
C7

good call. :thu:

[zenfascist]

Okay, here's what the wiring in my cab looks like:

http://i18.photobucket.com/albums/b125/zenfascist/DSCN0389.jpg

http://i18.photobucket.com/albums/b125/zenfascist/DSCN0390.jpg

I think someone did something wrong. :confused: Is that how it's supposed to look? I know very little about speaker wiring.

[Crescent Seven]

Originally posted by zenfascist
Okay, here's what the wiring in my cab looks like:

http://i18.photobucket.com/albums/b125/zenfascist/DSCN0389.jpg

http://i18.photobucket.com/albums/b125/zenfascist/DSCN0390.jpg

I think someone did something wrong. :confused: Is that how it's supposed to look? I know very little about speaker wiring.

Is that a 2x or a 4x cab? It's really quite simple to wire them in cleanly and correctly, and I recommend it, because it's not wired right and it looks like they used telephone wire for the lead to the plug.

Burdizzos, I think a set of wiring schematics for 1x, 2x, 4x, and 8x cabs would fit fabulously in this thread. :thu:
I'll try to find some later tonite...
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[Crescent Seven]

I drew these up. If they're wrong let me know.
http://i31.photobucket.com/albums/c381/velvet2112/2xschematic.jpg
http://i31.photobucket.com/albums/c381/velvet2112/4xschematic.jpg
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[burdizzos]

From Avatar Speakers:

Series

2 x 4 Ohm speaker = 8 Ohm load
2 x 8 Ohm speaker = 16 Ohm load
2 x 16 Ohm speaker = 32 Ohm load

http://www.avatarspeakers.com/pictures/wirserie2.gif


Parallel

2 x 4 Ohm speaker = 2 Ohm load
2 x 8 Ohm speaker = 4 Ohm load
2 x 16 Ohm speaker = 8 Ohm load

http://www.avatarspeakers.com/pictures/wirpara2.gif




Series / Parallel

4 x 8 Ohm speaker = 8 Ohm load
4 x 16 Ohm speaker = 16 Ohm load


http://www.avatarspeakers.com/pictures/wirserpa2.gif

[zenfascist]

Where can I find the wire to properly connect this stuff? Is there going to be soldering involved?

[Crescent Seven]

Originally posted by zenfascist
Where can I find the wire to properly connect this stuff? Is there going to be soldering involved?

Regular speaker wire works good, but get the single strand stuff. If you try to do it with the double-strand wire you'll probably get your wires crossed. Make sure you use 2 different colors, also, it help alot.
As far as soldering, you should do it on the speakers if you can; if not, get some blade terminal connectors, crimp 'em on the wire, and slide them on the terminal. The input jack should definitely be soldered. Some people aren't comfortable soldering on their speakers, but if you slide a dry cloth under the carriage to protect the cone, you'll be fine.
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[zenfascist]

http://i18.photobucket.com/albums/b125/zenfascist/DSCN0394.jpg

http://i18.photobucket.com/albums/b125/zenfascist/jack.jpg

That's what my jack looks like. I know the pics aren't great, but I'm confused as to which part is positive and which part is negative (where's the tip and the ring?). There are two little prong things, as you can see, and one is sandwiched in between two other pieces of metal, and one isn't. :confused:

[Crescent Seven]

HHAHA! That's telephone wire!:D

Ok, take a regular guitar cable, and plug it into the jack. The tip of the plug is insulated from the body of the plug; the tip is positive, the body is negative. You'll see that there are 2 places where the jack contacts the plug; each of those pieces is insulated from the other. The part that contacts the tip leads to the positive terminal, and vice versa.
Please, please rewire your cab! You'll be so much happier; you might even notice a difference in the sound not using that telephone wire...:D
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[zenfascist]

Oh, don't worry, I'll be doing it today. And I'll be emailing that stupid bastage that sold it to me to stop wiring his shit with phone wire. He seems to be upgrading and selling lots of cabinets and whatnot on ebay, so he deserves to be bitched at. :)

EDIT: And thanks for the help. :thu:

[Crescent Seven]

Originally posted by zenfascist
Oh, don't worry, I'll be doing it today. And I'll be emailing that stupid bastage that sold it to me to stop wiring his shit with phone wire. He seems to be upgrading and selling lots of cabinets and whatnot on ebay, so he deserves to be bitched at. :)

EDIT: And thanks for the help. :thu:

Always.
Send him my cheezy wiring diagrams while you're at it. It looks like he wired it in series, so if those are 16ohm speakers in a 2x10 you've been playing through a 32ohm cab.:mad: Even if they're 8ohm speakers you'd have a 16ohm cab...
Wire it in parallel and you'll have either a 4 or 8 ohm cab, unless they're 4 ohm speakers, in which case you'd have a 2ohm cab and would want to wire in in series to get to 8ohms.
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[burdizzos]

Here's a quick reference on speaker wire and load handling ability.


Wire Gauge---- Current Capacity Based on 60C rated cable.
10----------------30
12----------------20
14----------------15
16----------------10
18-----------------7
20-----------------5
22-----------------3
24-----------------Don't even think about it


The quick formula for your amp would be P = (I^2)*R

I = sqrt(P/R)

Where:
I is Current
P is Power
R is Speaker impedance


So, if you've got a 250 watt amp driving an 8 ohm cab, your amp is putting out 5.5 Amps.


The electrical rule of thumb is to go 30% more than you need. This is probably a good idea with speakers and amplifiers as well.

[agedhorse]

Where did you get the current vs. AWG chart? I suspect that this will apply only for very short wireruns, and heating might be an issue at that, especially atthe terminations. For longer runs, voltage drop will need to be accounted for, as it will affect damping factor.

[burdizzos]

Yeah, I thought those looked a bit high. Upon further review, those were for semi rigid cables rated to 80C.

I'll change them to the standard 60C rated stuff that most of us are going to be using.

Most of us are using less than 6 foot runs for speaker cable, so I don't think voltage drops and damping really need to be considered.

[agedhorse]

80 degrees C is indeed pretty toasty:D

Most certainly, for 6 feet, voltage drop isn't an issue, but for someone thinking the recommendations are universal while building speaker cables for a PA for example, might be surprised at the results;)

[burdizzos]

Originally posted by agedhorse
80 degrees C is indeed pretty toasty:D

Most certainly, for 6 feet, voltage drop isn't an issue, but for someone thinking the recommendations are universal while building speaker cables for a PA for example, might be surprised at the results;)


Anyone pushing 1000+ watts over 50 feet on 20 gauge wire gets what they deserve. ;)

[Crescent Seven]

Originally posted by burdizzos



Anyone pushing 1000+ watts over 50 feet on 20 gauge wire gets what they deserve. ;)

Lines burned across their floor and hands?:confused:
What's the big deal?? It only hurts for a few seconds.:D
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[J.]

Series / Parallel

4 x 8 Ohm speaker = 8 Ohm load
4 x 16 Ohm speaker = 16 Ohm load
http://www.avatarspeakers.com/pictures/wirserpa2.gif


This is the exact same wiring scheme only a bit cleaner in my opinion:
http://ebassist.com/photopost/data/500/247series_parallel.GIF

[agedhorse]

Originally posted by burdizzos



Anyone pushing 1000+ watts over 50 feet on 20 gauge wire gets what they deserve. ;)
Absolutely:D

[agedhorse]

Originally posted by Crescent Seven


Lines burned across their floor and hands?:confused:
What's the big deal?? It only hurts for a few seconds.:D
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And it feels so good when it stops:D

[Crescent Seven]

Originally posted by agedhorse

And it feels so good when it stops:D

It feels even better when you get done picking the melted plastic out of your burns.
I had some wires catch fire in my car when I wired my CB straight out of my fuse panel (I was 16 and stupid), so I reached down and grabbed the wire and pulled.
I still have a scar on the inside of my left hand from that.:mad:
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[zenfascist]

Well, I rewired it. I haven't had to solder anything since metal shop, so they ended up a little messy. No biggie, though, everything works fine. I still have a farting cabinet though. :mad:

[mlwarriner]

just wondering...since i'm fairly worthless with a soldering iron...


would the new improved avatar crossover setup work well with the burdizzos mod? i've ordered one of dave's new jack plate assemblies before, to reload into an avatar cab (mostly for the speakon jack), but i left the stock tweeter in it.

i'm thinking of doing the burd mod on my peavey 4x12 and possibly on an avatar 1x12 that i might be picking up too...

[burdizzos]

I' imagine that the new Avatar crossover would work fine with a galaxy driver, the downside is that hte crossover point is probably around 2kHz.

One of the benefits of using a galaxy driver is that it has frequency response down to 100 Hz. If it is crossed over at 500 Hz, you get to enjoy the smooth midrange that the driver offers. If it is crossed over at 2kHz, it will sound better than the stock horn, but its full potential will not be realized.

[mlwarriner]

Originally posted by burdizzos
I' imagine that the new Avatar crossover would work fine with a galaxy driver, the downside is that hte crossover point is probably around 2kHz.

One of the benefits of using a galaxy driver is that it has frequency response down to 100 Hz. If it is crossed over at 500 Hz, you get to enjoy the smooth midrange that the driver offers. If it is crossed over at 2kHz, it will sound better than the stock horn, but its full potential will not be realized.

problem is, the wiring diagrams you posted in page 1 make zero sense to me...and as i mentioned before, i'm useless (like a cub bear with mittens on) with a soldering iron...

[burdizzos]

Originally posted by Jazz Ad
Keep the good work coming guys ! :thu:
I learnt a lot of things just browsing the thread.

I also cleant it up a bit to strictly remain on topic.

Cool thanks.

We can probably go ahead and move it to the FAQ section.


Anyone with questions not answered here can PM me.

[burdizzos]

Originally posted by mlwarriner


problem is, the wiring diagrams you posted in page 1 make zero sense to me...and as i mentioned before, i'm useless (like a cub bear with mittens on) with a soldering iron...

If that's the case, then I'd recommend using a ready made crossover. Try it with the Avatar unit and see how it sounds.

You could ask your local guitar shop guy to assemble the parts for you.