Wanting to build a pair of top quality bookshelf speakers - Help!

[Swerd]

Even then, once they are installed in any room other than the one they were tuned in, the frequency response goes to hell, and top-end reflections/bass decay modes all shift around.

I just tuned the frequency response of my Legacy Studio HD's in a separate thread, and even though these are really good speakers that are supposed to be relatively flat as tuned by Legacy, the room interaction wreaks havoc on even the best of designs/implementations.

I think that's exaggerating things. If it were always true, any competently made speaker with a crossover, sold either commercially or as a DIY kit, could only work in the room in which they were built. We know that isn't the case.

Are you talking about the bass frequencies, below 200 Hz? Or are you talking about the full audio range? The distances between walls, floor, and ceiling in a typically sized room in a home are known to have a large effect on the frequencies below roughly 200 Hz. But above that, speakers sound similar in most rooms.

 

[Steve1580]

Your last photo made it all very clear. No that much separation would not, in my opinion, be a major problem. The 13' wide built-in unit doesn't rule out narrow (9 or 10" wide) floor standing or stand-mounted speakers in a 20' wide room. It depends on how far away the listeners sit, where further away would be better than closer. For example, I have 2 floor standing towers, each about 8" wide. They stand about 10' or 11' apart, just outside a somewhat similar wall cabinet unit (not built-in). The listening position is a sofa about 9' away. Instead of facing them directly ahead, I "toe" them in, angling them toward the center of the sofa. So, towers or stand-mounted speakers, that far apart could work.
From your photo, my 1st choice would be floor standing towers located just outside your shelves, or (2nd) vertically stand-mounted Mid woofer-Tweeter-Mid woofer (MTM) speakers in the same location, or (3rd) similar MTM speakers, standing vertically in the large bay in your built-in shelves. I wouldn't go for smaller speakers with one mid woofer and one tweeter (MT) in a room as large as yours.

I'd rather avoid moving speakers back and forth between two locations, but that's just my personal preference.
Expansion isn't the only problem with a speaker cabinet, a 6-sided box. Hardwoods, good for musical instruments, are not good for loudspeaker cabinets because hardwoods have sound frequencies at which they naturally resonate. That can alter or color the sound. Avoid that with composite woods such as ply or MDF.

Your idea of hardwood veneered plywood could be very nice looking. Based on your work with those built-in cabinets, I guess you can easily do all the wood work. Just the same, I'll ask these questions:

1. Can you make miter cuts for all the cabinet panels so the ply edges don't show at the seams?
2. Do you have a router and a circle cutting jig of some kind? That's the best way to cut holes for flush-mounting the drivers.

The wife and I looked at moving the sub over to the other side of the wall unit and then placing a tower next to it. To the left is a door entry and would make it too constricted. So I suppose I am left with option number 3. With that being the case, is there some consensus on a Mid woofer-Tweeter-Mid woofer (MTM) speaker setup that is well regarded?

On the subject of woodworking tools, yes I have both a table saw and miter saw that I have dialed in to within several thousands. I also have a fairly tidy router, router table with fence that let me do all kinds of cool tricks. On the ply ends I was thinking of routing edges and trimming with hardwood. I don't use bisquits, I have a Festool Domino that makes joints so tight that you could conceivably get away without gluing the joints (although I always do).

Would really appreciate thoughts on a MTM setup.

Thank you again for all the help.

 

[Steve1580]

@Steve1580 – I just got up to speed by actually reading this whole thread.

If I understand correctly, you have a room with about 20'×15' listening space. It has built-in bookshelves that have at least two shelves. The lower shelf is 16" deep × 16" high × 30" wide and the upper shelf is 16" deep × 30" high × 30" wide. I saw the attached picture of one of the shelves. What that photo doesn't show is how the shelves are placed in the room.

From that photo, I can see one of the shelves in which you might place a speaker, but I don't understand how you would use speakers mounted on stands. Where would the stands go? And why are floorstanding speakers not suitable? They have a similar footprint to speaker stands.

I agree with TLS Guy when he said "Putting speakers inside shelves can be problematic." It is important that the speakers be located so that the tweeter, or a point mid-way between the woofer and tweeter, is at a similar height to the listeners' faces (or ears) while they are seated. In bookshelves, it is also important that any speaker be placed such that its front panel (often called the 'front baffle' in speaker building) be at the front edge of the bookshelves, or even protruding a bit. Finally, if the speaker cabinet has a port tube, it would be better to locate the tube on the front baffle instead of at the rear of the cabinet. If a cabinet design shows a rear mounted tube, it can be relocated on front as long as the cabinet width and interior volume are unchanged. It may make the cabinet taller or deeper than in the original plans.

For any speaker with multiple drivers in one cabinet, it is important for acoustic reasons that the cabinet sit vertical and not sideways. Each driver should be arranged above or below the other drivers. Work with your wife on questions of cabinet finish, appearance, and general location, but do not compromise on the vertical alignment or the height above the floor of the speaker cabinets.

If you can fit a speaker cabinet that is 8" wide × 18.5" tall × 12" deep, you might consider building pair of the Zaph Audio ZA5.3 MTM speaker kits available through Madisound. Cabinet plans are included at that web site. MTM speakers, with two mid-woofers, will do better in a room of your size.

Somewhere in your posts, you mentioned using hardwood in your build. For speaker cabinets solid hardwood should be avoided. Instead, use MDF or good quality plywood such as Baltic birch. You can finish those cabinets with any veneer or paint you wish.

I just reread your post, the top shelf is 30" wide 30" tall and 12" deep. Sorry for the confusion. The bottom shelf is 30" wide, 16" and the bottom juts out to 16". I'm sure that presents even more restrictions. Sorry again for the confusion.

I should point out the two bottom shelves are fully adjustable for height and are a full 16" deep. I I set the shelf down to the required height the center of the speaker would be slightly lower than listening height. Hope that gets me somewhere good!

 

[Swerd]

On the subject of woodworking tools, yes I have both a table saw and miter saw that I have dialed in to within several thousands. I also have a fairly tidy router, router table with fence that let me do all kinds of cool tricks…

That's great. You could probably teach me many things .

For the hardwood edges, were you thinking of something like this? These are 8" wide. Made with MDF and cherry veneer, with a solid cherry strip (roughly 1×1) around the edges of the front baffle, rounded over with a ¾" round over bit. (No, I did not make these .)

The wife and I looked at moving the sub over to the other side of the wall unit and then placing a tower next to it. To the left is a door entry and would make it too constricted. So I suppose I am left with option number 3. With that being the case, is there some consensus on a Mid woofer-Tweeter-Mid woofer (MTM) speaker setup that is well regarded?

There are a lot of DIY designs for MTM speakers available. I'd have to look into it before coming up with a short list. Good kits, with or without cabinets, are available through Parts Express, Madisound, and Meniscus Audio. I'd start looking at those. Pay attention to price and cabinet dimensions.

I just reread your post, the top shelf is 30" wide 30" tall and 12" deep. Sorry for the confusion. The bottom shelf is 30" wide, 16" and the bottom juts out to 16". I'm sure that presents even more restrictions. Sorry again for the confusion.

I should point out the two bottom shelves are fully adjustable for height and are a full 16" deep. I I set the shelf down to the required height the center of the speaker would be slightly lower than listening height. Hope that gets me somewhere good!

I want to understand the dimension question clearly. If you are thinking MTM bookshelf speakers, they will be about 8" or 9" wide and tall enough (roughly 18" to 22", depending on size of mid woofer) for two mid woofers and one tweeter, all aligned vertically, like this picture.

With your adjustable shelves, what is the range of heights available on the 2nd or 3rd shelf down from the top of your cabinets?

 

[Steve1580]

That's great. You could probably teach me many things .

For the hardwood edges, were you thinking of something like this? These are 8" wide. Made with MDF and cherry veneer, with a solid cherry strip (roughly 1×1) around the edges of the front baffle, rounded over with a ¾" round over bit. (No, I did not make these .)

There are a lot of DIY designs for MTM speakers available. I'd have to look into it before coming up with a short list. Good kits, with or without cabinets, are available through Parts Express, Madisound, and Meniscus Audio. I'd start looking at those. Pay attention to price and cabinet dimensions.
I want to understand the dimension question clearly. If you are thinking MTM bookshelf speakers, they will be about 8" or 9" wide and tall enough (roughly 18" to 22", depending on size of mid woofer) for two mid woofers and one tweeter, all aligned vertically, like this picture.

With your adjustable shelves, what is the range of heights available on the 2nd or 3rd shelf down from the top of your cabinets?

Looking at those cabinet builds I'm not so sure I could teach you much. Great Work!
I really like the look of lighter woods highlighted by darker woods (sapele, mahogany, black walnut, etc.) or the reverse combination. So I was thinking of a maple main portion highlighted with the darker wood. Before understanding the problem with total hardwoods, I was thinking a patterned combination of some of those. With all that said, I really like your tower cabinets. Again, great work!

So if you look at the attached picture the shelves that are at the same level as the TV and above are unfortunately fixed and cannot be moved. There is one adjustable shelf in the middle of the space below and I can go from to any height up to 31.5 inches and I have just about 16 inches of depth. Although I would like to keep the two level setup, so probably about 20 inches high would be ideal. If I lowered the shelf to give about 20 inches of height, it would put the speaker relatively close to ear level while sitting. I hope that all makes sense.

Steve

 

[Swerd]

So if you look at the attached picture the shelves that are at the same level as the TV and above are unfortunately fixed and cannot be moved. There is one adjustable shelf in the middle of the space below and I can go from to any height up to 31.5 inches and I have just about 16 inches of depth. Although I would like to keep the two level setup, so probably about 20 inches high would be ideal. If I lowered the shelf to give about 20 inches of height, it would put the speaker relatively close to ear level while sitting. I hope that all makes sense.

Thanks for explaining that, I get it now. Still, with as much as 31.5" of height & 16" depth, you should have no problem fitting in most any MTM bookshelf speaker with 5½" or 6½" diameter mid woofers on either side of the TV.

I think it would be worthwhile to wait to see what idea TLS Guy has in mind. If he could assist with the driver selection and crossover design for a bookshelf MTM speaker, while you build the cabinets and assemble everything, it is likely to be excellent.

Looking at those cabinet builds I'm not so sure I could teach you much. Great Work!
I really like the look of lighter woods highlighted by darker woods (sapele, mahogany, black walnut, etc.) or the reverse combination. So I was thinking of a maple main portion highlighted with the darker wood. Before understanding the problem with total hardwoods, I was thinking a patterned combination of some of those. With all that said, I really like your tower cabinets. Again, great work!

I'd like to take credit for those speakers, but I built neither of them.

Those floor standing speakers are mine, but I bought them from Salk Sound (the model is Veracity ST). I showed them because I wanted to ask if you intended solid hardwood cabinet edges like that. I only wish I could make something that looks as good as Salk builds. The veneer is ropey cherry, and they were clear-coated without stain or dye. The photo is from a year ago when they were new. Now they've gotten darker and redder.

I like your idea of combining a light wood like maple with a darker trim wood. I've seen cabinets built by Salk that combine curly maple veneer and darker solid trim like mahogany, and they were gorgeous. I've also seen the reverse, crotch mahogany veneer framed by maple trim.

That other picture of the smaller MTM speakers I found online only as an illustration of vertical alignment. I do like the curly cherry veneer.

 

[Steve1580]

Thanks for explaining that, I get it now. Still, with as much as 31.5" of height & 16" depth, you should have no problem fitting in most any MTM bookshelf speaker with 5½" or 6½" diameter mid woofers on either side of the TV.

I think it would be worthwhile to wait to see what idea TLS Guy has in mind. If he could assist with the driver selection and crossover design for a bookshelf MTM speaker, while you build the cabinets and assemble everything, it is likely to be excellent.
I'd like to take credit for those speakers, but I built neither of them.

Those floor standing speakers are mine, but I bought them from Salk Sound (the model is Veracity ST). I showed them because I wanted to ask if you intended solid hardwood cabinet edges like that. I only wish I could make something that looks as good as Salk builds. The veneer is ropey cherry, and they were clear-coated without stain or dye. The photo is from a year ago when they were new. Now they've gotten darker and redder.

I like your idea of combining a light wood like maple with a darker trim wood. I've seen cabinets built by Salk that combine curly maple veneer and darker solid trim like mahogany, and they were gorgeous. I've also seen the reverse, crotch mahogany veneer framed by maple trim.

That other picture of the smaller MTM speakers I found online only as an illustration of vertical alignment. I do like the curly cherry veneer.

I would love to have TLS Guys help/counsel on this. His expertise is highly respected.

Do you think it would be possible to get a good MTM package say in a 20" high box?

Big problem with Cherry (and other hardwoods) is trying to prevent them from turning much darker. Once all the decisions are made I am thinking curly maple (ply) trimmed with sapele or black walnut. I am more of a mechanic and do not have aesthetic design skills.

 

[Steve1580]

I'm totally unclear on where you intend to place those stands. Please clarify.

To be permanent I would have to place the stands outside of the wall unit, which would be about 15 feet apart (per attached photo). I would greatly appreciate any other suggestions/help. The HSU sub is on the right side of the wall unit.

 

[Swerd]

Do you think it would be possible to get a good MTM package say in a 20" high box?

Yes.

I could be wrong, but I have the impression that TLS Guy is thinking about a speaker using the Zaph Audio ZA14W08 mid woofer. If he meant to use two of them in an MTM arrangement, they would probably require a cabinet 0.70 cubic feet (20 liters) that has external dimensions 8" wide, 18.5" tall, and 12" deep. The cabinet might be similar to this http://zaphaudio.com/ZA5/ZA5.3.pdf.

Knowing TLS Guy's preferences, he would probably want to use a silk dome tweeter of better quality, and somewhat higher price, than in a kit Madisound sells that uses two of these mid woofers. But the cabinet dimensions are determined by the mid woofer and not the tweeter, so if what I am imagining is what TLS Guy has in mind, the cabinet would be close or identical to 8" wide × 18.5" tall × 12" deep. This design does have a port on the rear of the cabinet. For your use, the port could be moved to the front, accompanied by an increase in height by a few (?) inches to accommodate the port.

But let's wait and see what he has in mind. I might be completely wrong. @TLS Guy ?

 

[Winkleswizard]

No doubt the Zaph MTMs could be improved upon, but they are really good as they are. So are the MTs. I have built both. Given your amp, either will give very pleasing results in your size room. My home theater is a bit bigger than yours and my mains are less sensitive than the Zaph's and they can play way louder than you should tolerate.

One major advantage of smaller speakers is placement flexibility. You can move them around your shelf unit to find where they sound best. If you are still undecided on bookshelf vs towers, try loaning some bookshelfs from a friend or local store. There are better practices that you should apply, but shy of a custom design for your space (difficult to optimize remotely), you can save a lot of time and money by test driving some speakers. If you decide on towers, I would give serious consideration to the Linkwitz LX mini. It is a state of the art design and can be tweaked to your room and tastes.

One additional note, The Zaph's are good but I prefer to run with grills off. In a home theater, shiny drivers can be distracting. I know your primarily concerned with music, but just thought I would share my experience. This is even more true if you use a center channel (which you should in a home theater with widely spaced mains).

Ww

 

[Steve1580]

No doubt the Zaph MTMs could be improved upon, but they are really good as they are. So are the MTs. I have built both. Given your amp, either will give very pleasing results in your size room. My home theater is a bit bigger than yours and my mains are less sensitive than the Zaph's and they can play way louder than you should tolerate.

One major advantage of smaller speakers is placement flexibility. You can move them around your shelf unit to find where they sound best. If you are still undecided on bookshelf vs towers, try loaning some bookshelfs from a friend or local store. There are better practices that you should apply, but shy of a custom design for your space (difficult to optimize remotely), you can save a lot of time and money by test driving some speakers. If you decide on towers, I would give serious consideration to the Linkwitz LX mini. It is a state of the art design and can be tweaked to your room and tastes.

One additional note, The Zaph's are good but I prefer to run with grills off. In a home theater, shiny drivers can be distracting. I know your primarily concerned with music, but just thought I would share my experience. This is even more true if you use a center channel (which you should in a home theater with widely spaced mains).

Ww

Thank you very much for your response. One question, do you see any advantage in my case in going with a pricier driver, like SEAS offerings for example? I am planning to replace my center speaker as well, although it will up high that is the only location that is doable.

Thanks again for your time and counsel.

 

[rojo]

Thank you very much for your response. One question, do you see any advantage in my case in going with a pricier driver, like SEAS offerings for example? I am planning to replace my center speaker as well, although it will up high that is the only location that is doable.

Thanks again for your time and counsel.

It's really difficult to say. Your limiting factor will be your placement options. With better placement, more expensive drivers would definitely be worthwhile. But in your current situation, you might be putting a shiny red bow on a stool sample. You know, bookshelf placement and stand mounting aren't your only options for wife acceptance. Did you happen to see the photos of the Heliums I linked earlier? See this post on the Parts Express forum Helium thread. Or maybe you could talk her into letting you have one of the bedrooms for your audio projects.

 

[Winkleswizard]

With speaker drivers there are points of diminishing returns as well as implementation considerations. There are great drivers from Seas and some other vendors and there are some expensive ones that have mediocre performance as well. Speakers are a system design effort that involve driver selection, cabinet and crossover design AND design validation to obtain optimal results. Passive crossover design requires good design software to minimize expensive iterations.

More drivers add complexity that requires a much more experienced designer and/or time to iterate through multiple redesign and test cycles. All of the above is why I advise using a known design from a reputable designer. There is rarely a simple change and fewer absolutes.

All this said, speakers are designed for specific applications. Lacking a very custom design effort, there are some known design considerations like baffle step compenation in passive crossover design. This needs to be considered if the speaker will mount closer to the rear wall or not...

If your center will be mounted above the tv, would use a mounting approach that allows it to be directed at the listening space.

Because there are a lot of possible considerations, it is very challenging to say what the "best" speaker is for any one person. Most purists consider a dedicated midrange as a must for music reproduction. But a good 2-way design will sound better than a mediocre multi-way design. Many like car analogies and like cars, speakers are electromechanical systems. It is practically impossible to build one that does everything well.

Ww

 

[Steve1580]

With speaker drivers there are points of diminishing returns as well as implementation considerations. There are great drivers from Seas and some other vendors and there are some expensive ones that have mediocre performance as well. Speakers are a system design effort that involve driver selection, cabinet and crossover design AND design validation to obtain optimal results. Passive crossover design requires good design software to minimize expensive iterations.

More drivers add complexity that requires a much more experienced designer and/or time to iterate through multiple redesign and test cycles. All of the above is why I advise using a known design from a reputable designer. There is rarely a simple change and fewer absolutes.

All this said, speakers are designed for specific applications. Lacking a very custom design effort, there are some known design considerations like baffle step compenation in passive crossover design. This needs to be considered if the speaker will mount closer to the rear wall or not...

If your center will be mounted above the tv, would use a mounting approach that allows it to be directed at the listening space.

Because there are a lot of possible considerations, it is very challenging to say what the "best" speaker is for any one person. Most purists consider a dedicated midrange as a must for music reproduction. But a good 2-way design will sound better than a mediocre multi-way design. Many like car analogies and like cars, speakers are electromechanical systems. It is practically impossible to build one that does everything well.

Ww

Thank you. Excellent advice!

 

[Steve1580]

I spoke with the guys at Madisound and for my situation they recommended three SEAS Loki MKii. In my reading it seems like SEAS are very highly regarded and he thinks it will work well for my situation. Any thoughts positive or negative? Thanks!

 

[Swerd]

I spoke with the guys at Madisound and for my situation they recommended three SEAS Loki MKii. In my reading it seems like SEAS are very highly regarded and he thinks it will work well for my situation. Any thoughts positive or negative? Thanks!

I wouldn't have thought of the Loki or recommended it. However, I emphasize, I haven't heard it.

Do you know what the difference is between the Loki Mk II and Mk III?

• This coaxial speaker does not have a smooth frequency response across the critical mid range, a range where our ears are most sensitive and where much music content lies. The red trace (below) bounces up and down as much a 5 dB between 850 and 2000 Hz. You will hear this.
• At higher frequencies, the tweeter response is ragged, more ragged than many non-coaxial tweeters.
• The cabinet will fit your space, and it has the port already mounted on the front.
• Its sensitivity of 82 dB is on the very low side. It will require a more powerful amp to drive.
• I think you can get sensitivity in the range of 85-87 dB (two mid woofers will accomplish that) and a smoother frequency response curve than the Loki.

If I remember correctly, I believe Dennis Murphy has had some direct experience with the Seas Loki. Dennis, please comment, if you care to respond.

 

[Winkleswizard]

In theory, I like the coaxial design but have no experience with the driver. I considered the earlier version of the Loki myself and here is what I found about the older design of the driver (from Zaph Audio website):

"The real issue with the driver is value. There is absolutely no way it's worth it's current cost nearly $160. (late 2008) For those considering a center channel, at that price you can build a 4-driver 3-way ZDT3C and it will outperform it in every way. The coaxial isn't a bad driver, but the cost kills it. I am a fan of many Seas products, but not this one. There could be some specific installation requirements that still make this driver a good choice regardless of cost."

This review was before he offered the even more cost effective ZA5 designs. The ZDT3C uses Dayton Audio drivers. I did not do the math, but suspect his value statement still applies.

Ww

 

[Swerd]

I am a fan of many Seas products, but not this one.

I have the same opinion.

 

[Steve1580]

In theory, I like the coaxial design but have no experience with the driver. I considered the earlier version of the Loki myself and here is what I found about the older design of the driver (from Zaph Audio website):

"The real issue with the driver is value. There is absolutely no way it's worth it's current cost nearly $160. (late 2008) For those considering a center channel, at that price you can build a 4-driver 3-way ZDT3C and it will outperform it in every way. The coaxial isn't a bad driver, but the cost kills it. I am a fan of many Seas products, but not this one. There could be some specific installation requirements that still make this driver a good choice regardless of cost."

This review was before he offered the even more cost effective ZA5 designs. The ZDT3C uses Dayton Audio drivers. I did not do the math, but suspect his value statement still applies.

Ww

I wouldn't have thought of the Loki or recommended it. However, I emphasize, I haven't heard it.

Do you know what the difference is between the Loki Mk II and Mk III?

• This coaxial speaker does not have a smooth frequency response across the critical mid range, a range where our ears are most sensitive and where much music content lies. The red trace (below) bounces up and down as much a 5 dB between 850 and 2000 Hz. You will hear this.
• At higher frequencies, the tweeter response is ragged, more ragged than many non-coaxial tweeters.
• The cabinet will fit your space, and it has the port already mounted on the front.
• Its sensitivity of 82 dB is on the very low side. It will require a more powerful amp to drive.
• I think you can get sensitivity in the range of 85-87 dB (two mid woofers will accomplish that) and a smoother frequency response curve than the Loki.

If I remember correctly, I believe Dennis Murphy has had some direct experience with the Seas Loki. Dennis, please comment, if you care to respond.

Disappointed, I thought I had good solution. Where to go from here. I really liked the idea of the smaller size cabinet. He said I should use the Loki as the center speaker as well.

 

[Steve1580]

Are there other sources I should consider, like Madisound? I know this sounds ridiculous but I was also wanting to leave the front open and I didn't like the looks of the SEAS coaxial.