# Future Gold-wood speaker build



## kingnoob (Mar 12, 2013)

Planning ahead for Build as I already have most the wood + 2 goldwoods.
Within 1-3 months I can probably build them.

8" woofershttp://www.parts-express.com/goldwood-gw-8pc-8-8-heavy-duty-woofer-8-ohm--290-314
Parts express suggests: Dimensions.
1 cubic foot, with a 2" diameter, 3" long port yielding an F3 of around 43 Hz.
Port http://www.parts-express.com/precision-port-2-flared-speaker-cabinet-port-tube-kit--268-348 x2

I am trying to decide which type of tweeter I want , But nothing too expensive I am on low budget.
I don't know how to build X-over so will probably buy pre made ones.
XO-http://www.parts-express.com/dayton-audio-27k-38k-hz-2-way-crossover-board--269-117
2.2khzhttp://www.parts-express.com/dayton-audio-22k-32k-hz-2-way-crossover-board--269-116


Tweeter Ideas 
Silk tweeter -$251idea#2
http://www.parts-express.com/dayton-audio-nd25fn-4-1-neo-silk-dome-tweeter-element-4-ohm--275-053
Horn tweeters I also like Econowave might work.

I am clueless which type of tweeter is best I never have built any DIY speakers.

I also have 2 Visaton woofers but they seem less impressive, might do something with them later on.http://www.parts-express.com/visaton-w200-8-8-woofer-8-ohm--292-584


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## dougc (Dec 19, 2009)

There is a lot that goes in to speaker design to match the drivers together and then to build a crossover for them. What are the Goldwoods? 3-way design is even trickier than 2-way. That said, I swapped out some faulty crossovers out of some 3-way CV towers with one of the PE crossovers and it sounded pretty good to me. It was better than the not working speakers at least. The easiest way for you to get something that sounds great is to buy a kit that is proven that matches what you want to have in the end.


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## kingnoob (Mar 12, 2013)

dougc said:


> There is a lot that goes in to speaker design to match the drivers together and then to build a crossover for them. What are the Goldwoods? 3-way design is even trickier than 2-way. That said, I swapped out some faulty crossovers out of some 3-way CV towers with one of the PE crossovers and it sounded pretty good to me. It was better than the not working speakers at least. The easiest way for you to get something that sounds great is to buy a kit that is proven that matches what you want to have in the end.


I know how to build the speaker boxes the , X over & tweeter choice confuses me, maybe with a L-pad I could adjust after build. How do you make L-Pads connect to Pre built X over?:T

I should just buy pre-built speakers but I want to see what I can do DIY


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## dougc (Dec 19, 2009)

Right! Me too, the box is the easy part though. There is a science behind all the other stuff that I don't understand either, yet, but I'm working on it. I believe that you could figure it out too. There is a LOT to read up on making crossovers to match the right tweeters with mids and woofers. If you buy a kit, then you still get to solder together the XO, build and finish the box, and then put it all together for the same price as buying some parts that are not proven to work together. Check out some sites that have sell the kits, like Madisound, Meniscusaudio, diysoundgroup, parts-express. Zaphaudio is great because he designs several different speakers, has built, and tested them, then shares the plans and the parts list for free. I built the Zaph ZDT3.5 and learned a lot about the other part of speaker building - the guts. Check it out! You will be thrilled with what you build and proud you did it.


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## fusseli (May 1, 2007)

You can easily make your own starter design using drivers of your choice and a premade crossover. The speakers will function fine, just keep in mind that if you want awesome performance the first time you should build someone's proven design like the Zaph kits. Also, look for data on the drivers you plan to use. From what I recall, the HD Goldwoods model pretty well. However, Zaph hated the GT-520 tweeter you want to use. Search the internet for Zaph's site and find his tweeter mishmash. Also stick to the impedances listed on the prebuilt xover as best you can, E.g. 8 ohms. Those textbook filters are only valid for that exact impedance.

If you continue with your own drivers and premade xovers, please do two things to get better results. You can probably come up with a okay speaker relatively easily going this route.
1) add a zobel filter to your woofer. This will make the impedance of the woofer more flat and easy for the premade "textbook" filter to work as intended. There are online calculators for this.
2) add an L-pad to reduce the tweeter down to the same SPL as the woofer. You should model your woofer in something like WinISD or WBCD to verify the bass performance of the box size that was suggested to you, then get the tweeter's 2.83V SPL to match the woofer's 2.83V sensitivity. There are online calculators for L-pads also.


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## kingnoob (Mar 12, 2013)

fusseli said:


> You can easily make your own starter design using drivers of your choice and a premade crossover. The speakers will function fine, just keep in mind that if you want awesome performance the first time you should build someone's proven design like the Zaph kits. Also, look for data on the drivers you plan to use. From what I recall, the HD Goldwoods model pretty well. However, Zaph hated the GT-520 tweeter you want to use. Search the internet for Zaph's site and find his tweeter mishmash. Also stick to the impedances listed on the prebuilt xover as best you can, E.g. 8 ohms. Those textbook filters are only valid for that exact impedance.
> 
> If you continue with your own drivers and premade xovers, please do two things to get better results. You can probably come up with a okay speaker relatively easily going this route.
> 1) add a zobel filter to your woofer. This will make the impedance of the woofer more flat and easy for the premade "textbook" filter to work as intended. There are online calculators for this.
> 2) add an L-pad to reduce the tweeter down to the same SPL as the woofer. You should model your woofer in something like WinISD or WBCD to verify the bass performance of the box size that was suggested to you, then get the tweeter's 2.83V SPL to match the woofer's 2.83V sensitivity. There are online calculators for L-pads also.


Good tips I gotta re-download WinISD :bigsmile:
Better than goldwood tweeter, Vifahttp://www.parts-express.com/vifa-bc25sc06-04-1-textile-dome-tweeter--264-1028


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## kingnoob (Mar 12, 2013)

what is a Zobel Filter got any links ?


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## fusseli (May 1, 2007)

A Zobel filter makes a driver, which usually are inductive loads, look more like a resistor to the amplifier. The result is a flatter impedance that will play much better with the pre-made crossovers. If you Google "zobel filter calculator" the top results are just what you need.


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## fusseli (May 1, 2007)

Here's an illustration. Recall that your xover is specified as "2700Hz at 8 ohm." I've attached the simulated impedance of your Goldwood driver in 1cuft tuned to 43Hz, notice how it is rarely actually at 8 ohms (on the left)? Adding the zobel will make the driver look closer to it's nominal value (on the right), which is especially important at the crossover frequency. Without this the performance of the premade crossovers will be very poor.


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