1337 5.1 speaker design and build

[slisgrinder]

Hey guys,


as you can see, I am starting my design process and build and I am a complete noob at this so I will most definitly need some help along the way...


First the concept design

L, R, RL, RR speakers are tower speakers with the following vertical driver placement:

[6" mid sealed enclosure] - [1 1/8" tweeter] - [6" mid sealed enclosure] - [8" woofer vented in the front]

The center is a horizontal speaker with the following driver placement:

[6" mid vented in the front] - [1 1/8" tweeter] - [two 6" mids in a sealed enclosure] - [1 1/8" tweeter] - [6" mid vented in the front]

There are going to be two 15" folded horn subwoofers with the horn facing the front. One in the front of the room and one in the back of the room.

I realize that this design is packed with problems but would like to know what the problems are. I also know how massive these subs are going to be. Also the reason for all the vents/ports and the horns facing front is because these speakers will be integrated into the walls of a basement so that they are flush against the walls...


So all constructive criticism is welcome including design changes like making the drivers of the folded horn subwoofers smaller if required even placement of the subs or woofers in the towers etc...

for the tweeters I want something that when turned up loud wont crackle and for the mids I had these in mind...

woofer

Subwoofer

 

[its_bacon12]

To be honest, that center is going to be all sorts of problems. As are your tower/surround plans.

Surrounds are supposed to be ambiance to the LCR so they don't have to be the same speaker.

And as I said in that other thread, I would HIGHLY advise taking an already designed (and free to use) speaker from Missions Accomplished!

These have been designed, tweaked and built on numerous occasions by many people. Not the mention the designers themselves.

As for a folded horn, that is pretty unpractical too and you'll see why once you look at how much space is required for a small subwoofer, let alone 2 15's.

Those drivers you picked too will be difficult to integrate together as well. Save yourself the trouble 500 times over by looking through the designs from HTGuide and pick one that suits you best. Most of the LR designs also offer a CC as well.

Subwoofer, the easiest way to do a DIY sub is sonotube, and those RSS390HF-4's you picked are not a good candidate for being alligned in a vertical axis placement due to suspension sag over 5% - I actually was going to get the same drivers last week but decided on a pair of Mach 5 Audio IXL 18.2.2 drivers instead.

I did my first DIY home theater stuff last summer and this is my advice to someone starting. Designing a crossover alone is next to impossible unless you have the right tools and understanding of what to implement and how each component effects the overall frequency response.

 

[TLS Guy]

Hey guys,


as you can see, I am starting my design process and build and I am a complete noob at this so I will most definitly need some help along the way...


First the concept design

L, R, RL, RR speakers are tower speakers with the following vertical driver placement:

[6" mid sealed enclosure] - [1 1/8" tweeter] - [6" mid sealed enclosure] - [8" woofer vented in the front]

The center is a horizontal speaker with the following driver placement:

[6" mid vented in the front] - [1 1/8" tweeter] - [two 6" mids in a sealed enclosure] - [1 1/8" tweeter] - [6" mid vented in the front]

There are going to be two 15" folded horn subwoofers with the horn facing the front. One in the front of the room and one in the back of the room.

I realize that this design is packed with problems but would like to know what the problems are. I also know how massive these subs are going to be. Also the reason for all the vents/ports and the horns facing front is because these speakers will be integrated into the walls of a basement so that they are flush against the walls...


So all constructive criticism is welcome including design changes like making the drivers of the folded horn subwoofers smaller if required even placement of the subs or woofers in the towers etc...

for the tweeters I want something that when turned up loud wont crackle and for the mids I had these in mind...

woofer

Subwoofer

I think you need to start with a simpler project.

For a start horns are very difficult to design. You have picked a sub driver that is totally unsuitable for horn loading. For horn loading you need high sensitivity low Qt drivers.

You will need to study the research and papers by Dr Bruce Edgar to understand what you are doing and how to design a horn. William Fitzmaurice has also made contributions in recent years, but the King of horns is Dr Bruce Edgar.

Your other speakers sound like a mess. Don't add crossover points where you don't need to. Making a three way with bass and mids having the same or close diameters makes little if any sense, except for the center where there is merit to having the tweeter above the mid and at the sides the woofers. However you need to make the crossover points outside the speech discrimination band, to offer significant advantage over the poor horizontal MTM configuration. This means crossover points in the 350 to 400 Hz and 4 to 5 kHz ranges. I would suggest you consider a coaxial driver like one from SEAS for the center.

I think you need to do a lot more reading and research before starting a project this ambitious. Also get some successful simpler projects under your belt first. Above all learn how to design and build seamless crossovers with smooth frequency response. That takes a lot of skill and experience.

I'm worried you are about to waste a lot of time money and effort, if you embark on this without thorough knowledge and the gaining of some experience.

If you look at the links in my signature, and I can assure you that was very far from my first speaker project. In fact it was designed after around 50 years of building speakers.

Don't let this advice put you off a path of speaker building, it is great fun and rewarding, but you can't climb a mountain starting at the peak.

 

[Swerd]

slisgrinder

Welcome to the forum. The short answer to your list of questions is:

Listen to its_bacon12. I think he speaks from experience.​

If you are a complete noob to DIY speaker building, I don't want to pour cold water on your enthusiasm, but your ideas need a lot of work. I'm not sure where to begin…

First the concept design

L, R, RL, RR speakers are tower speakers with the following vertical driver placement:

[6" mid sealed enclosure] - [1 1/8" tweeter] - [6" mid sealed enclosure] - [8" woofer vented in the front]

The tower speakers might work, but I have to ask, do you understand what is involved in crossover design? It takes a lot more than a Parts Express catalog, a circle saw, and an imagination. The crossover is critical to a speaker. You never specified a tweeter. How do you know if these drivers will work together? Designing a 2-way is MANY TIMES easier than a 3-way. Don't go there if this is your first DIY build. Find a tried and tested design and copy it. There's no harm in that. You will avoid a lot of disappointment and frustration.

Your idea of building these speakers into the wall will introduce whole cans of worms that could easily be avoided by building towers. There is a reason why people prefer to move their speakers away from the wall.

The center is a horizontal speaker with the following driver placement:

[6" mid vented in the front] - [1 1/8" tweeter] - [two 6" mids in a sealed enclosure] - [1 1/8" tweeter] - [6" mid vented in the front]

Lining up 4 midrange drivers like that will create a series of standing waves and cancellations that will make for a very poor center speaker. Look up Comb Filter on google or wikipedia.

There are going to be two 15" folded horn subwoofers with the horn facing the front. One in the front of the room and one in the back of the room.

Do you have a folded horn design specific for these subwoofers? If not, don't go there. I believe these subwoofers were designed to put into sealed cabinets. If you like the idea of folded horns, find a design and use the driver it specifies.

for the tweeters I want something that when turned up loud wont crackle

As mentioned above, this needs some work.

 

[j_garcia]

Another thing I would mention is that putting them in a wall space so they appear flush is really not a great idea either. Your design would also need to take that into account since this sort of placement is generally a bad idea acoustically. If you want flush, use in wall speakers and an I/B sub.

 

[its_bacon12]

I don't mean to be a debbie downer or anything, just trying to save you from wasting massive amount of time, effort and money.

Once you get into DIY a bit, you'll understand all the points we've lined up for you. It's also good to see someone else start up DIY as it's a lot of fun and it really consumes my thought a lot of the time.

Not to mention the feeling of doing it yourself and having it turn out great. Please, we're here to help not discourage so any questions let em fly

 

[lsiberian]

Do you have a system yet?

If not I will suggest you build a recession buster kit.

Get your feet wet. They are surprisingly good speakers. I use a pair for my fronts and they sound very nice. IB subs are very good usually, but don't start with them. Get your feet wet first.

First find out if you have the right tools. It's hard to DIY without a saw.

Let's start with getting you the right saw or making sure you have one.

You have two choices for doing this stuff. A table saw or a circular saw.

A table saw is great if you have a good one and some help usually. large sheets are tought to handle by yourself on a table saw. So it's not what I usually suggest for a speaker builder. Unless you have a good one.

A Circular saw can be good with a good guide and lots of practice. It's also much cheaper.

Review safety. Even if you've worked a million times. Experienced folks are the ones usually killed by saws.

 

[slisgrinder]

This is what I am trying to achieve but by replacing the mids with the M6N or M5N from HiVi then also replacing the tweeters with this and the woofer with this...

For the center channel, I want to do the same as above like replacing the mids and tweeters like this... The only other modification I want to make is have the ports in the front or facing the front but at an angle away from the listener. These speakers are not going to be part of the wall but rather "integrated with the wall but they will still remain tower speakers...


The only question lies is what type of Subwoofer design and driver will get me that kick in chest effect that I talked in the earlier thread in the subwoofer section. The only reason I thought of the folded horn design, is because thats the type that seem to have the kick in chest effect...

 

[slisgrinder]

or maybe I should go for following one simply because its simple


clicky here plz...

 

[Swerd]

Both those designs are at least reasonable. If you start changing drivers in that HiVi design you will have to redo the crossovers. Why not keep the HiVi drivers?

Jim Holtz's statements are an excellent design. I haven't heard them, but I know several experienced DIY designers who have heard them, and they all liked them a lot. You would do well to make them exactly as Holtz designed them.

 

[slisgrinder]

actually the reason for switching out the speakers with the ones that I linked, is because I want them to look good... And I was wondering - TLS Guy, can I build the setup you have linked in your sig? They look good and bet that they they sound finominal plus I have more space to do it. The only thing that I am going to change is the center channel and add a Sub and finally keep it a 5.1 setup instead of 7.1.

So with your permission, could I replicate your setup??? On second thought, I will start small then work up. I guess my goal is to replicate your setup in the future, now thats a drive!

 

[its_bacon12]

actually the reason for switching out the speakers with the ones that I linked, is because I want them to look good... And I was wondering - TLS Guy, can I build the setup you have linked in your sig? They look good and bet that they they sound finominal plus I have more space to do it. The only thing that I am going to change is the center channel and add a Sub and finally keep it a 5.1 setup instead of 7.1.

So with your permission, could I replicate your setup??? On second thought, I will start small then work up. I guess my goal is to replicate your setup in the future, now thats a drive!

His setup is pretty much a reference set up using some VERY high end SEAS drivers, those big woofers look like the W26fx's which are over $300+ per driver. Tweeters are T25cf's are what like $200+ a driver and the midranges are the w12 or w15cy's which are $150+ per driver.

Needless to say, that's a LOT in drivers alone.

Heh, I'd definitely say start out a lot easier than that. You can get a decent DIY build for less than the cost of one W26fx driver.

 

[slisgrinder]

lol, u r right, i m going to go for the Statements as they are easy and simple...I am simply going to replace the mids and woofers with the ones I linked earlier...there will be changes needed but they should be minor...what changes am I suppose to expect?

 

[TLS Guy]

lol, u r right, i m going to go for the Statements as they are easy and simple...I am simply going to replace the mids and woofers with the ones I linked earlier...there will be changes needed but they should be minor...what changes am I suppose to expect?

Now you are getting closer to a starting project. However do not substitute drivers. If you do that you have a different design. The crossover would be very different and require a complete redesign. The enclosure size is determined by the Thiel/Small parameters and therefore the enclosure dimensions would be different.

I agree that building my speakers would not be a beginners project, though you are welcome to give it a try down the road. For me at least the carpentry was complicated. drawing the plans was months of work alone. Winding two lines together was a prolonged wet towel job! Its_bacon12 is correct, the driver cost is high. Also it requires six amp channels to drive the front main speakers and two to drive the center. So you have the investment of eight amp channels for the fronts alone. Two channels for the sides, and four for the rears, for a total of 14 amp channels. So duplicating this system would be pricey. The drivers for the surrounds and rears are Dynaudio drivers NLA OEM. The four bass drivers for the rears are the venerable KEF B 139s which I have had for since the seventies. They still turn up on eBay now and again, but usually fetch high prices.

I think you ave been given the correct advice to build an established design. That will get you into the building mode. At the same time you can study how to correctly load speakers and understand the fundamentals of crossover design.

 

[slisgrinder]

I can replace the mids with these as they are very similar in specs and a lot cheaper just a little less powerful, I would like to keep the ribbon tweeter the sub I will keep as is so am I good to go?

 

[its_bacon12]

You really have to get rid of the mindset that speakers are interchangeable because they simply are not. Those drivers are nothing at all alike really other than the fact they're both 4". That little Tangband titanium mid is one of the nicest sounding drivers I have ever heard, and the HiVi can not compete with it.

I don't expect you to understand this stuff quite yet but it will come in time.

Also, those statements are pretty big, just so you know what to expect.

 

[TLS Guy]

You really have to get rid of the mindset that speakers are interchangeable because they simply are not. Those drivers are nothing at all alike really other than the fact they're both 4". That little Tangband titanium mid is one of the nicest sounding drivers I have ever heard, and the HiVi can not compete with it.

I don't expect you to understand this stuff quite yet but it will come in time.

Also, those statements are pretty big, just so you know what to expect.

The above is absolutely true. The frequency response and roll offs of the drivers a re different. If you substitute drivers, you are back to square one with the crossover. I don't think you have the skills to design a crossover yet.

Crossovers are not brick wall. They have to sum with the acoustic roll off of the drivers selected to sum to a flat response. Different drivers never have the same frequency response curves.

My advice is to build the design to the exact specifications, then you will be good to go. Otherwise you are set for a sonic disappointment, not to go.

 

[Swerd]

You really have to get rid of the mindset that speakers are interchangeable because they simply are not. Those drivers are nothing at all alike really other than the fact they're both 4". That little Tangband titanium mid is one of the nicest sounding drivers I have ever heard, and the HiVi can not compete with it.

Agreed.

Usually crossovers are designed last after drivers are selected and installed in a suitable cabinet. Substituting different drivers will almost certainly require a new crossover and a different cabinet. It is very rare to subsitute another driver where you can sucessfully plug and play with no other changes.

 

[slisgrinder]

ok point taken. I will stick with the drivers specified. out of curiosity, if I keep the box volume the same for each the woofers and mids and change the dimensions, does that affect the sound??? I am not saying I will, I was just wondering...

 

[Swerd]

ok point taken. I will stick with the drivers specified. out of curiosity, if I keep the box volume the same for each the woofers and mids and change the dimensions, does that affect the sound??? I am not saying I will, I was just wondering...

The width of the front baffle is important to the overall design. The crossover designer has made assumptions about how near the speaker cabinet will be to the wall behind it, and has built in some compensation for that in the crossover. This is called diffraction loss or baffle step response. Read this article for an explanation.

Change the baffle width and you need to change the baffle step compensation. The same is true for the distance between a speaker and the wall behind it. If you build a speaker that has about 3-4 dB baffle step compensation (a typical amount) built in the crossover, and place the speakers directly against the wall or built into the wall, they will have too much bass and sound boomy. Even if you're a bass freak, it won't sound good.