Beat the recession! Highly cost effective DIY speaker build using the Audax AP170Z0

[TLS Guy]

In September I was visiting my father in England. He asked me to build a set of speakers for their sun room. A pair of Audax AP170Z0, Aerogel 6.5 inch bass mids and a pair of Scanspeak D 29 tweeters were available.

I built a pair of 1 cu. ft. two way speakers with these drivers. They were astonishingly good performers, with an excellent bass, mid range and HF.

It has come to my attention that Parts Express have these woofers available at a bargain basement price of just $22.

Audax has just been sold by Harmon International to this outfit, .

They say they will produce a more limited range of speakers. The above drivers are listed as archive drivers. So how long they will be available from Parts Express is open to question.

The Audax line of Aerogel cone drivers has always been well regarded.

This driver at first sight does not look promising, as there is a rise in response above 1 kHz, with a 9db peak from a prominent break up mode at 3.8 kHz. However with notch filter and careful crossover design this driver can be nicely tamed, to build speakers of very superior quality.

I have put together a family of designs around this woofer to take a bite out of the recession!

I have included my original design using the fairly expensive Scanspeak tweeter.

I have adapted the design for the highly cost effective Vifa DTG 05/06, at $22.56 each. So a set two way speakers could be built for less than $90 in driver cost. A two and a half way or MTM set can be built for around $130 in driver cost. This is highly cost effective for speakers that will easily compare with speakers in the 1 to 2 K range per pair, as long as the enclosures are built well with good bracing.

I have also included a crossover for the SEAS 27 TDC tweeter which represents excellent value for money at just under $40.

On my web page about this driver, you will find highly cost effective designs for a couple of two ways, with crossovers for three tweeters. You will also see the circuit for the lower fill driver if you want to build one of the two two and a half ways. There are also a couple of MTMs and circuits for both the VIFA and SEAS tweeters.

If you have some wood working skills and want a speaker upgrade, this is a relatively inexpensive way of doing it.

 

[highfigh]

Thanks for doing all of the work on this. Any opinion on the D27TG-35?

http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=264-526&ctab=2#Tabs

 

[TLS Guy]

Thanks for doing all of the work on this. Any opinion on the D27TG-35?

http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=264-526&ctab=2#Tabs

I have not used that tweeter, but the off axis response does not mirror the axis response well, and the tweeter has a higher Fs. It would not be suitable for the MTM design. Also I would have to rework the crossovers to use that tweeter, it is significantly different from the tweeters I selected

I used the Vifa 27 TG 05/06 tweeter in a cost effective bookshelf a while back and the speaker was a lot better then the sum of the parts. My son is using them in is basement for his TV audio system down there currently.

I used it in a design for member Guiria using that tweeter and he was very pleased with those speakers. I'm sure he would not mind if you sent him PM. His signature has "love em," after the speaker description.

The SEAS 27 TDC tweeter is well known to be excellent value for money, and has a little better dispersion pattern.

However the real point of this post is to give people a chance to be able to enjoy some speakers that will perform far better than anyone would imagine from the dollars spent. However there will be sweat equity!

If any one has trouble sourcing the crossover parts I can help. I can build the crossovers if there is a member or two, good with the saws and routers, but not putting together circuits.

 

[lsiberian]

I know DIY subs offer greater performance for the money, I'm assuming building speakers would give a similar result. I'm wondering if you think these speakers would be an upgrade from my current ones(see signature). Or if they would match well with a Perfect build. I'm really like all the DIY info on this forum.

 

[TLS Guy]

I know DIY subs offer greater performance for the money, I'm assuming building speakers would give a similar result. I'm wondering if you think these speakers would be an upgrade from my current ones(see signature). Or if they would match well with a Perfect build. I'm really like all the DIY info on this forum.

I really can't comment, as I have never heard those speakers. I can say that the spec is comparable to the small 0.43 cu.ft bookshelf design. However the I cu.ft. two way, the two and a half ways, and the MTM designs, will have significantly better bass, if the enclosures are constructed correctly.

Any of the speakers using that Audax driver I published on my site, will be very good DIY projects for a minimal capital investment. The sweat equity involved is another matter. However you get to learn something along the way, increase your skills and have the satisfaction of listening to something you built.

I see no problem mating them with a perfect build.

 

[JLMEMT]

This is a great project!
I see this as about the holy grail for me right now. It would give me more quality than I could otherwise see myself reasonably attaining for many years.

I recently decided that an Onkyo 806 was too good to pass up. I knew that I would also need to replace my speakers, but honestly I had no idea! I currently have cube speakers that were part of a HTIB with a passive sub that was also part of that kit. I thought I could cheat and use my old AVR to power the sub until I found the sub I wanted. I can't get that to work out right either.

I would love to build these, but am not sure if I can sucessfully pull it off. I have never built a speaker before. I do have some basic constuction and woodworking skills and I would say decent tools. About the only thing I would lack is a table saw, which I think I could work around.

 

[TLS Guy]

This is a great project!
I see this as about the holy grail for me right now. It would give me more quality than I could otherwise see myself reasonably attaining for many years.

I recently decided that an Onkyo 806 was too good to pass up. I knew that I would also need to replace my speakers, but honestly I had no idea! I currently have cube speakers that were part of a HTIB with a passive sub that was also part of that kit. I thought I could cheat and use my old AVR to power the sub until I found the sub I wanted. I can't get that to work out right either.

I would love to build these, but am not sure if I can sucessfully pull it off. I have never built a speaker before. I do have some basic constuction and woodworking skills and I would say decent tools. About the only thing I would lack is a table saw, which I think I could work around.

I will give you every assistance to try and have a successful outcome to your project.

It sounds as if you have enough woodworking skills to start. What about reading the crossover circuits and building them? I can build them for you, or help guide you through the build, and trouble shoot them if necessary.

If it is home theater you want, I assume you would be interested in building one of the two full size options for mains, and may be the small bookshelves for surround and the 1 cu. ft MTM for center.

 

[Seth=L]

what does the build look like?

 

[JLMEMT]

I will give you every assistance to try and have a successful outcome to your project.

It sounds as if you have enough woodworking skills to start. What about reading the crossover circuits and building them? I can build them for you, or help guide you through the build, and trouble shoot them if necessary.

If it is home theater you want, I assume you would be interested in building one of the two full size options for mains, and may be the small bookshelves for surround and the 1 cu. ft MTM for center.

That sounds great!! But be warned, I will need some serious guidance I am guessing. If you don't want to do that or don't have the time for that I fully understand.

We use it for mostly HT, but I think that I would enjoy music a lot more as well with the proper equipment, so I want to do both as much as reasonably possible.

I know nothing about crossovers, etc. I do have some basic circuit reading experiance and a fair ammount of automotive type wiring experiance.

I was thinking the larger mains with a "well matched" center, what ever that would be for these. I may very well keep my cubes for the sides and back for the time being, due to time and money. While I would eventually like to match them all I don't think that I have to be in a huge rush for that. As I said I believe this will already be such an improvement that I won't know any better for a while. I have never had the pleasure of listening to a truely great sustem as some of you own, so ignorance is bliss. If I step up a little slower it may help to slow down the outflow of money. If I do it all quikly I will want to change something else soon anyway. ;-)

 

[TLS Guy]

what does the build look like?

The 2.5 way tower needs to be 2 cu.ft, + volume of braces, drivers and crossovers. This will bring the internal volume Vt to around 4000 cu. inches.

The internal width should be able to be kept to 7" and if the internal height is 40" the internal depth will be 14.25". Out side dimensions will depend of material chosen. If 3/4 material is chosen, with 1.5 inches for the front panel. then the cabinet would be 41.5" inches high X 8.5 inches wide X 16 1/2 inches deep.

The tweeter would be mounted as high as possible, with the bass mid below that as close to the tweeter as possible, and the fill driver below that, as close to the bass mid as possible. The port would be below the fill driver.

Braces should be placed every 9" or so.

 

[TLS Guy]

That sounds great!! But be warned, I will need some serious guidance I am guessing. If you don't want to do that or don't have the time for that I fully understand.

We use it for mostly HT, but I think that I would enjoy music a lot more as well with the proper equipment, so I want to do both as much as reasonably possible.

I know nothing about crossovers, etc. I do have some basic circuit reading experiance and a fair ammount of automotive type wiring experiance.

I was thinking the larger mains with a "well matched" center, what ever that would be for these. I may very well keep my cubes for the sides and back for the time being, due to time and money. While I would eventually like to match them all I don't think that I have to be in a huge rush for that. As I said I believe this will already be such an improvement that I won't know any better for a while. I have never had the pleasure of listening to a truely great sustem as some of you own, so ignorance is bliss. If I step up a little slower it may help to slow down the outflow of money. If I do it all quikly I will want to change something else soon anyway. ;-)

You would have the following choices for you mains.

2 cu.ft two and a half way, 2 cu. ft MTM, or 1 cu. ft MTM.

For the center I would use the 1 cu.ft MTM

For the surrounds the 0.43 cu.ft bookshelf. If you want surround dipoles the design can be modified for two tweeters. However, I do not use dipoles, and do not find sound localizes to the surrounds, and have found imaging between surrounds and mains to be excellent with monopoles.

I doubt those Audax drivers will be available much longer, so if you want to proceed, then I would purchase 8 or 10 of those Audax drivers depending on whether you plan to go 5.1 or 7.1. That way you can put together a well matched system.

 

[JLMEMT]

You would have the following choices for you mains.

2 cu.ft two and a half way, 2 cu. ft MTM, or 1 cu. ft MTM.

For the center I would use the 1 cu.ft MTM

For the surrounds the 0.43 cu.ft bookshelf. If you want surround dipoles the design can be modified for two tweeters. However, I do not use dipoles, and do not find sound localizes to the surrounds, and have found imaging between surrounds and mains to be excellent with monopoles.

I doubt those Audax drivers will be available much longer, so if you want to proceed, then I would purchase 8 or 10 of those Audax drivers depending on whether you plan to go 5.1 or 7.1. That way you can put together a well matched system.

I will probably go ahead and get the 10 drivers for eventual 7:1. The one tweeter choice is available at the same place so I could order all at once. The other option is only about $10 more a driver. I would be willing to pay that if they are noticeably better though. What is your opinion on that?

Also on the dipole idea. You don't like them, or don't think they are needed, or what? In my case my room is fairly small and my side speakers will be nearly right over a few of my additional seats. For that reason I wondered if maybe dipole would be a better option. I don't have any real experience with them though, just a thought at this point.

 

[TLS Guy]

I will probably go ahead and get the 10 drivers for eventual 7:1. The one tweeter choice is available at the same place so I could order all at once. The other option is only about $10 more a driver. I would be willing to pay that if they are noticeably better though. What is your opinion on that?

Also on the dipole idea. You don't like them, or don't think they are needed, or what? In my case my room is fairly small and my side speakers will be nearly right over a few of my additional seats. For that reason I wondered if maybe dipole would be a better option. I don't have any real experience with them though, just a thought at this point.

I personally think the SEAS tweeter is worth the extra $10. The dispersion pattern is better.

I have updated the 2.5 way crossover for that tweeter, and updated the parts list.

I personally would not use dipoles. I have found at least in my rig you do not localize to the surrounds, even when close. If you want to do it though I can modify the crossover for the book shelf, just let me know.

You should have a nice system at a good price when you get everything built.

Do you want me to source the crossover parts fro the MTM and bookshelf crossovers, or are you able to do that?

Those Audax woofers are an incredible value right now.

 

[JLMEMT]

Okay. I will go with the SEAS then, and skip the dipole idea. I will try to get the mids ordered in the next day or so.

I will at least need some help with the crossover parts. I will try to look at them and see if I can figure out what I need, but any ideas for sources would be great.


I am looking forward to it! Thanks for all of your help so far!!

 

[TLS Guy]

Okay. I will go with the SEAS then, and skip the dipole idea. I will try to get the mids ordered in the next day or so.

I will at least need some help with the crossover parts. I will try to look at them and see if I can figure out what I need, but any ideas for sources would be great.


I am looking forward to it! Thanks for all of your help so far!!

I'm unclear of your choice of mains. Are you going to use the 2 cu.ft 2.5 ways or the 2 cu.ft MTMs?

I have already have sourced the 2.5 way components on my website. I will add the others later.

 

[JLMEMT]

I'm unclear of your choice of mains. Are you going to use the 2 cu.ft 2.5 ways or the 2 cu.ft MTMs?

I have already have sourced the 2.5 way components on my website. I will add the others later.

I am sorry! It was way past bed time when I posted the last one.

I was thinking the 2.5 ways with the audax driver's. That should be the better option sound wise, isn't it?

I haven't had a chance to thoroughly go over things. I will try to do that tonight.

 

[TLS Guy]

I am sorry! It was way past bed time when I posted the last one.

I was thinking the 2.5 ways with the audax driver's. That should be the better option sound wise, isn't it?

I haven't had a chance to thoroughly go over things. I will try to do that tonight.

I think it depends. That is why I gave the option. I'm partial to the MTM configuration personally.

In this unit, the sensitivity of the MTM is higher, and effectively doubles amp power. Some people don't like MTM because of the narrow vertical dispersion, but that has the advantage of reducing floor and ceiling reflections.

The big advantage of the 2.5 way, is that by shelving in the second fill driver, then the lower mid and upper bass losses due the narrow cabinet can be completely compensated.

Anyhow you have both designs and its your choice.

You will of course need the parts for one MTM unit for the center. I would make the center the one cu. ft. unit rather than the two.

With these drivers you have to have a horizontal MTM configuration, which is common, but less than optimal. If you could place the center vertical instead of horizontal, that would be optimal.

 

[JLMEMT]

I think it depends. That is why I gave the option. I'm partial to the MTM configuration personally.

In this unit, the sensitivity of the MTM is higher, and effectively doubles amp power. Some people don't like MTM because of the narrow vertical dispersion, but that has the advantage of reducing floor and ceiling reflections.

The big advantage of the 2.5 way, is that by shelving in the second fill driver, then the lower mid and upper bass losses due the narrow cabinet can be completely compensated.

Anyhow you have both designs and its your choice.

You will of course need the parts for one MTM unit for the center. I would make the center the one cu. ft. unit rather than the two.

With these drivers you have to have a horizontal MTM configuration, which is common, but less than optimal. If you could place the center vertical instead of horizontal, that would be optimal.

I have looked over, I think, all of this topic on your site. Honestly I don't have enough audio experience so many of the numbers mean little to me. I could obviously never design something like this with the knowledge I have, but that is why I am fortunate that you already have!

Reading over all of it, and your comments here, I think you are saying that you prefer the MTM design in the 2 cu. ft. boxes for the main and the 1 cu. ft. design for the center. I honestly feel that I don't have enough knowledge to have a preference at this point though.
I have a fairly small room, but it is open in the back. There is no chance of changing to a different room in the near future, I would have to add on as there just aren't many choices in our home now. So, due to my room I don't think that the lack of vertical dispersion would be any deficit for me. For the HT focused seems to be better.

I will also need to build a sub at some point to replace my cheap small one, but that will be after this and probably after a break as well.

It appears, to me, that the crossover for the MTM is a little cheaper to build and more simple as well. I think that would be a plus in this case.

I want to keep the project as cheap as possible, but would rather up a component a few dollars, such as the tweeters, if it is worth the money. I would be happy to keep this set for a long time. I am very open to your, and anyone's, suggestions.

I do want to get the Audax drivers ordered while I can get them, and this cheaply, but I also want to understand what I need and am doing first.

I am a little lost on the horizontal MTM comment. I have read that debate elsewhere, so I understand that vertical is better from the audio aspect of it. Are you saying that even the mains will be horizontal? Or just the center is different for some reason?

Thanks again for you help and patience on this!

 

[TLS Guy]

I have looked over, I think, all of this topic on your site. Honestly I don't have enough audio experience so many of the numbers mean little to me. I could obviously never design something like this with the knowledge I have, but that is why I am fortunate that you already have!

Reading over all of it, and your comments here, I think you are saying that you prefer the MTM design in the 2 cu. ft. boxes for the main and the 1 cu. ft. design for the center. I honestly feel that I don't have enough knowledge to have a preference at this point though.
I have a fairly small room, but it is open in the back. There is no chance of changing to a different room in the near future, I would have to add on as there just aren't many choices in our home now. So, due to my room I don't think that the lack of vertical dispersion would be any deficit for me. For the HT focused seems to be better.

I will also need to build a sub at some point to replace my cheap small one, but that will be after this and probably after a break as well.

It appears, to me, that the crossover for the MTM is a little cheaper to build and more simple as well. I think that would be a plus in this case.

I want to keep the project as cheap as possible, but would rather up a component a few dollars, such as the tweeters, if it is worth the money. I would be happy to keep this set for a long time. I am very open to your, and anyone's, suggestions.

I do want to get the Audax drivers ordered while I can get them, and this cheaply, but I also want to understand what I need and am doing first.

I am a little lost on the horizontal MTM comment. I have read that debate elsewhere, so I understand that vertical is better from the audio aspect of it. Are you saying that even the mains will be horizontal? Or just the center is different for some reason?

Thanks again for you help and patience on this!

Actually I don't have preference one way or another. If it is mainly for HT, then I think I would go with the MTM, especially in a small room.

No, I'm suggesting all speakers be vertical if possible. Putting the center in the usual horizontal gives a lobing pattern 90 degrees from optimal. In order to make a good center, that can be placed horizontal, it is necessary to use a coaxial driver, or build a three way center, with the tweeter above the mid.

However this is a budget project.

I have sourced all your components. It is now on my site.

I would make the left and right mains the 2 cu. ft. cabinet, and the center the 1 cu. ft. cabinet. I would make the surrounds the 0.43 cabinet.

Brace the cabinets well, put in braces every 6 to 9 inches. Cover 50% of internal surfaces with Rockwool, also known as mineral wool, available from your lumbar yard. Use a mask when handling it. Make sure the whole of the rear walls behind the drivers are covered.

The total cost of your electrical parts will be $790. Total cost with the drivers will be $1234. That is an average cost per speaker of $176. So you should be able to put the whole speaker system together for around $1500, which is excellent value.

If you decide to go with the two and a half way mains the cost goes up to $1298.

When you get around to building the sub, I would think seriously about doing a kappa perfect 12 build, from these forums.

Now all you need is board glue and time. It should be a fun and rewarding project.

 

[JLMEMT]

I was actually looking at your site while you were adding. I was looking at it and when I moved pages more popped up. Thank you for doing all that work and adding all of that!
That is a little more than I was hoping to spend, but oi recognize there is a lot of value in the complete set. I think I will go ahead with it. I am just trying to decide if I will do it all at once or in a couple of groups.

I understood that you were saying that vertical is better, but didn't understand the comment about these driveres needing to be used horizontally. That is one of those things that I may need you to explain to me before I actually start building.

I looked at the Kappa build and thought it was a little more than I needed. But it will probably fit in well with this set and round out my system nicely. But it may have to wait a bit.