Large floorstanding, "Project 110db"

[cujet]

OK, here is the deal. I have a set of DIY 6.5" w/dome WTW (or MTM if you prefer) speakers with subs that sound fairly good. However w/o the sub, they lack bass and punch. With the subs the bass is a bit muddy for music.

I want smooth, clean sound with punch when required. So a large set of floorstanding speakers are in order.

I was thinking about the following:

a) 2ea woofers in a 4 Ohm config (I like sealed!) maybe 12's maybe 15's, muddy is not ok.
b) 2ea midrange, not sure if I want 5.5 mids or dome mids.
c) 1ea dome tweeter, silk or metal is OK as long as it is not harsh.
d) No horns of any type!
e) I desire flat response well into the very low freq's.
f) 5cf enclosure is OK with me, but not too much larger.

I took a look at the PE Magna Cum Laude design, but the drivers may be a bit low end for my tastes. While cost is a factor, I do not mind spending more for good, clean sound and reliability.

I would consider other options such as 4ea 8's or 4ea 10's.

Here is where I need your advice:

1) Should I use mid range 5.5" (or similar) cone drivers or a dedicated dome (or other type) midrange driver crossed over a bit higher?
2) Does a large number of midrange drivers have a negative effect on sound quality?
3) Same question for tweeters?
4) Are automotive small sealed box type subs worth considering?
5) I have read that lower Xmax drivers sound better, true?
6) Can some of you suggest drivers?
7) Using 4ea smaller woofers might allow a higher crossover point to the mids, is this worthwhile?
8) Any other suggestions would be welcome!

I have the skills and tools necessary for the construction. However I do not have a degree in "speaker engineeering".

Thanks!

Chris

[JonMarsh]

Try taking a look at CJD's designs in the Mission's Accomplished sub forum- I think you might find some things you like- or at the least, a very good jumping off point. Low frequency extension is often a function of box tuning, which derives from size, so combining moderate efficiency and low frequency response will result in LARGE enclosures due to Hoffman's Iron Law.

Regarding the whole Xmax related question, I have to say it's more a matter of motor design- especially with focus on distortion and Le reduction efforts. For example, the RS315 series would usually be called "long excursion/high Xmax" compared with standard woofers, but the use of Faraday rings helps control inductive rise substantially, and together with good cone design, makes use up to several hundred Hz feasible. Another example of this design philosophy is the Aurasound NS12 and NS10.

Automotive subs are probably not suitable, because they're usually equipped with stiffer suspensions; quite literally they're intended for high output boom boxes in the 40-55 Hz area, NOT for deep extension.

Check out some of the threads here on larger floorstanding concepts in development, like Jed's New Three Way Design Coming Up, and the Three Way Design study; that's an example using the Aurasound 12's which should have effective bass performance into the upper teens. Similar systems are in the development and planning stages by other forum members.

[Brian Bunge]

Here's the large 3-way MTMWW towers that Chris (cjd) and I designed. It uses dual Dayton RS 10's, dual Dayton RS 7's, and a single RS28a aluminum dome tweeter. I think they will meet your requirements pretty closely.

http://www.htguide.com/forum/showthread.php4?t=11873

[cujet]

Thanks for the link. I have been looking at these for a while. I really like 'em. But I would really like larger ones. In the past I owned 10 inch speakers and I clearly understand the performance of this size.

Chris

[---k---]

:rofl: new people!

I've heard CJD's 3-ways. I think you are mistaken.

and, you're not going to do anything with multiple 12s or whatever if you're going to limit yourself to a 5cuft enclosures.

[kingpin]

In your thread over at PE Chris mentioned that you vould use the Dayton RS 10" subs.
Although I don't they are a direct replacemnet for the rs270's they will need some adjustment in the crossover.
How much, I do not know. Chris would have to weigh in on that one.

Mike

[Brian Bunge]

Ryan,

Dual RS 12's (either HiFi or HO) will work in these same cabinets. Of course, the xo would have to be changed.

Mike, I believe using the 10" RS subs would require separate outboard amplification in order to properly level match with the rest of the system.

[kingpin]

edited

[cujet]

I have looked at the Dayton RS 315 12 inch subs as suggested. But I think the result would not be 4 ohms.

As far as the cabinet size, I have the room for BIG, but would prefer reasonable. I am not limited to 5cf. Just thought that was a nice looking size.

That was one of my questions, are the small sealed box enclosure type woofers any good? Or are they too power hungry?

I fail to see how 2ea 10 inch woofers will closely compare to 15's. But maybe I should hear the speakers Brian and CJD have built. It might be just fine. :E

Chris

[Brian Bunge]

No, dual RS subs will not allow for a nominal 4 ohm load. You can wire them in series for 8 ohms or parallel for 2 ohms. Any special reason why it MUST be a 4 ohm load?

Subs designed for small, sealed enclosures are good for use as subwoofers. You do not want to try to use them as woofers that are going to be crossed over above 80Hz.

Dual 10's can compare pretty closely to a single 15, but not dual 15's. It's really a question of exactly which drivers you are comparing. Size alone won't dictate which will have higher output capabilities.

[cjd]

Rather than getting stuck on driver size, why not specify your frequency response goals and your SPL goals?

Dual 12" RS subs will drop into the same cabinet but you'll lose a lot of sensitivity. Total redesign. And not worth it.

IMHO the best solution is to augment this with an IB sub crossing 40-60Hz. Second best would be some large-box sealed subs again crossing 40-60Hz.

You can stretch things a little bit with this or that trick but in the end, the results are not as good as if you have a little more placement option with the sub.

C

[cujet]

SPL, I have no idea what my curent setup produces. I do have a calibrated sound level meter that I use for aircraft sound surveys. I will try and get some meaningful information. At times I like it at near rock concert levels. Other times, I like to listen to music (such as Alison Krause) at normal levels.

My goal is to get rid of the subs! I want bass response FLAT down to below the audible range without DSP.

Isn't that what High Fidelity means?

Every once in a while, I hear a set of speakers that knock my socks off. I heard a big set like this a while back and have wanted them ever since.

4 Ohms is my requirement due to the ability of my old Adcom and Yamaha to drive 4 Ohms to high power levels. That is the way I like it.

Thanks for all the input, I do appreciate it!

Brian, I sent you a PM.

Chris

[cjd]

Any good amp capable of driving a 4ohm load can similarly drive an 8ohm load to high power levels.

You've gotta have "subs" somewhere.

"Without DSP", I don't understand what you mean by this.

If you want small boxes, you've got to boost response down low one way or another - either in electronics (which often ALSO help you deal with room nodes, something key to good sound) or via a port or PR or similar type system (which has both benefits and drawbacks, like anything else).

An IB sub is the best way to "get rid of the subs" while gaining sound quality and response reach. But that's only IF it's possible or realistic in your current room.

I think a 3-way might stretch to your goals. A 4-way may be the better way to go.

[cujet]

I suppose I would consider an IB sub. I have never heard one. That is not something average homeowners build.

I took a look at the Dayton ST385's. It seems they are lower end products, with 2 positive reviews.

How would 2 of these perform in a sealed box. I see the sugggested sealed box volume is quite small, like 2cf. Going larger may help extend the lows. What do you guys think? Can you suggest a volume that would provide what I need?

Thanks!

Chris

[cjd]

You know, you might just like Ryan's recent project merged with kingpin's project. ish. Say, a 15" sub on either end of Ryan's WMTMW configuration.

The ST385 will not give you that much over the RS270S-8's. Ok, yeah. It'll give you more. But SQ isn't there. Not a bad woofer, but it doesn't have the excursion to deliver low bass in any quantity.

C

[cujet]

cjd, The ST385-8 has more Xmax than the RS270-8's. Is it really not a good choice?

What do you think about a 5cf box for 2 of these?

Thanks,

Chris

[PaulC]

Very knowledgeable fellows have supplied their opinions. As far as I can see they are right dab on the money.

Think about what they have said for a bit is my advice.

Another thought is that well done sub 50 hertz bass requires the room being part of the design process. What I believe is the best (certainly the most accessible) low frequency sound reproduction implementation information available on the net is linked from this site. There is a learning curve of course, shucks, and darn it!

Good luck, and have fun!

[ThomasW]

My goal is to get rid of the subs!

Doesn't matter if they're stand-alone boxes or built into the mains they're still 'subs'.

Main problem building them into the mains is that you're limited to the position the mains occupy in the room for placement. Unfortunately that's not always the optimal location for the subs

I want bass response FLAT down to below the audible range without DSP.

Because?

Not much out there for infrasonic analog EQ, the Rane PE-17 or Symetrix 551/552 (if you can find either) have a 10Hz hinge point.

Isn't that what High Fidelity means?

"High Fidelity" is a marketing term from the 1950's, who knows what it means?

The ST385-8 has more Xmax than the RS270-8's. Is it really not a good choice?

Neither of these are a good choice if you actually want to meet your stated goal of ....

At times I like it at near rock concert levels

I suppose I would consider an IB sub. I have never heard one. That is not something average homeowners build.

Actually most IB sub builders are just 'average home owners'.

At this point the main issue is your stated goals and the budget probably aren't in synch...

BTW, why don't you tell us a little more about your existing subs? We might be able to fix what ails them...

[cujet]

OK, Thanks for the guidance! I reviewed all the responses again.

When time permits, I will listen to Brian's speakers before making my choice.

Ok, yeah. It'll give you more. But SQ isn't there. Not a bad woofer, but it doesn't have the excursion to deliver low bass in any quantity.

Here is where I get confused. I see comments like this and I read what I want to, my fault. But I read "it'll give you more". Let's forget box size for a second, how much more? Just a bit more low end extension? If that is the case, why bother? If it is quite a bit more SPL and low end extension, that is what I want.

My current subs are junk KLH units used on movies only. I have access to Velodyne subs from my boss' house, which I have borrowed. I do not like them any better on music with my current speakers.

cjd suggested using the 10 inch project towers and sub crossing over at 40HZ. I have not heard a setup exactly like this, it might be "just the ticket". Maybe a large "sonosub".

FWIW, I know what I like in a speaker. I like a lot of sharp punch in the low end. I despise muddy bass.

I get to play with quite a bit of high end equipment as my boss (a multi billionaire) has all sorts of toys. Some impressive stuff indeed. I do not like small speakers. Finding a large set that sounds clean is tough indeed.

Chris

PS,

cjd suggested "ou might just like Ryan's recent project merged with kingpin's project. ish. Say, a 15" sub on either end of Ryan's WMTMW configuration."

Could you post a link to this?

[cjd]

So many questions. Long as you're asking you're learning, and getting closer to what you really want.

Ryan's project - this would lend itself to a top/bottom mounted sub and some box dimension changes to accomodate these while maintaining volume. Since I have not measured yet I could mock different baffles to get a crossover specifically built for this setup (I will still recommend going active below this to give you tuning flexibility). Whether you want this or not I think I will take these measurements just to put another concept in the bag.

On the ST385-8: It will give you a little more low end extension (will probably be up a few dB over the RS270S-8 at 20Hz). It won't really give you any more SPL/watt (except where its larger diameter and lower Fs improve low end response). It's short on excursion as a *sub* driver (which the RS270 is NOT). 40Hz is the absolute low point that might work - it'll be room dependent.

Low bass, If you want no boom, you're going to want room correction (digital is the way to go - works great for a sub). And you may want to stay away from ported or PR systems and go sealed. The bigger the box sealed, the more effortless and crisp the bass can be - an IB sub being the ultimate, where it's essentially a HUGE box behind a sealed sub.

We've all tried to say this different ways, but: You want a sub if you want the low low frequency extension. Your goal is not "no sub" but something else.

C

[---k---]

And here is Kingpins project:

http://htguide.com/forum/showthread.php4?t=20872

That adds two subs to Chris's previously mentioned 3-ways.

[cujet]

OK, thanks, I understand the need for a quality sub for the very bottom.

cjd, I have a bit of trouble understanding what you wrote. Could you please clarify the following for me? You said:

""On the ST385-8: It will give you a little more low end extension (will probably be up a few dB over the RS270S-8 at 20Hz). It won't really give you any more SPL/watt (except where its larger diameter and lower Fs improve low end response)"". Do I not want this? I understand that you are saying that the larger speaker will produce a bit more low end by a few db. This sounds like what I am wanting.


"It's short on excursion as a *sub* driver" But I was thinking about using it (or similar, something better?) as a standard woofer.

"It's short on excursion as a *sub* driver (which the RS270 is NOT)" Are you saying that the RS270 is not a sub driver or not short on excursion?

"40Hz is the absolute low point that might work - it'll be room dependent." Are you saying that using 2ea ST385-8 per large enclosure will respond to a lower limit of 40HZ before rolling off? Or are you hinting at the crossover point for a sub?


cjd, I feel like an idiot for not knowing these things. It has been years since I built any speakers. So, what you understand by looking at speaker specs, I can only guess. In my experience, a sealed box Qts of much less than .8 resulted in soft but extended bass response. I also thought that using 2 drivers in a single enclosure helped extend low end response.


Thanks for helping out a bonehead like me. I am sure, that with enough help this will result in a fantastic system!

Chris

[cjd]

You're confusing a lot of different conversations.

The RS270 is not a sub. It's a woofer. The ST385-8 is short on excursion for sub duty, and short on high(er) frequency quality for a woofer. If you're really focusing on SQ, that is.

The 40Hz was the lower limit I gave for the WWMTM 3-way using two of the RS270 as woofers for crossing to a sub. Brian's in-room measurements show surprisingly solid response to 20Hz with the RS270... Down 5 or 6dB IIRC.

If you want a 3-way with 15" drivers in there that fits in with the design philosophy most folks around here hold, you'll want Aura or Dayton RS (they have clean top end frequency extension), probably cross to 8" mid-woofers, and a waveguide tweeter. It'll be big. But I think such a beast would absolutely meet all your other goals. There are a couple tweeters you can cross to an 8" without waveguide and possibly meet your SPL goals.

C

[cujet]

A quick test of my current system produced 104db "C" slow with slow peaks of 112 on just the front 2 speakers. Adding the surround speakers and subs produce 108db "C" slow. I can reach a maximum of 111db "C" slow but the speakers simply cannot handle that level of power.

So I my goal is 110db "C".

It would be fine to be louder, but the far more important thing is I would like much cleaner sound.

cjd, thank you for making things clear.

Chris

[cjd]

110dB at what distance?

@3M that's pushing it for the WWMTM 3-way (though I've had mine there) - @2M it can happen. Tweeter is the weak link in this case - that's a lot to ask of a little dome. And that's stupid loud, regardless.

Remember you lose 6dB as distance doubles.

C

[cujet]

My chair is about 15 feet away. I took the measurements with the sound level meter at ear height where I sit. Moving the meter makes some small differences.

cjd, I work at the airport, and I work with jet aircraft. 120db is common. My ears hurt just thinking about it :B

I was wondering about that single tweeter. My current WTW setup uses older Audax soft domes and they are not up to the task. I should have known.

I truly dislike horn or compression drivers. What do you suggest?

doesn't the use of 2 dome tweeters result in undersirable performance?

[69Stingray]

You can clone these:

http://www.jamo.com/admin/public/Download.aspx?File=Files%2fBilleder%2fR+90%2fR909_detail_3.jpg

http://www.jamo.com/admin/public/Download.aspx?File=Files%2fBilleder%2fR+90%2fR909_pblack_1.jpg

[cjd]

I truly dislike horn or compression drivers. What do you suggest?

That you leave your preconceptions at the door. You're operating with a LOT of preconceptions - all, I am sure, with solid basis in past experience somewhere or other. They're very useful, but not when used to make blanket statements that eliminate a whole slew of possibilities. Rather, be more specific about your dislikes. I wouldn't suggest a compression driver necessarily, but a waveguide may be a requirement.

A waveguide tweeter will have little difference in sound compared to the same tweeter without, except that it will be able cross lower more comfortably and will be slightly more directional, both of which can be advantageous.

As for cloning... any more, the only thing worth doing is taking a good concept someone has had and building off it. Thomas (and Jon) have quite a history of cloning and have, I believe, always found the results to be less than what they could have been had they simply used it as a starting point and done their own thing. Though always fun. (Those Whisper klones were insane...)

C

[Dennis H]

I truly dislike horn or compression drivers.

Maybe what you dislike is the horns you have heard, not the compression drivers. If you really want it as loud as you say, no 'hifi' driver is going to get it. A good compression driver such as those from BMS will get you where you want if you use a 'waveguide' (subtle difference from a horn -- goes for fidelity rather than max SPL) like the DDS.

[cujet]

I listened to a set of B+W top of the line speakers today. I was impressed. I also found it interesting that they were dual 10 inch (carbon fiber) woofers, a 5 inch (kevlar) mid and a (diamond dust covered) dome tweeter. They sure sounded good. I think the salesman said they were about 20 grand!

B+W also makes a stellar HT setup, for about 25 grand using much the same formula but with 4ea 15 inch subs.

It certainly is interesting that they follow a certain pattern also found here on this forum!

Chris

[cjd]

I think (but do not know for sure since I was never told exact brands) the WWMTM's have been compared (with favorable outcome) to those B&W's...

C

[Brian Bunge]

I think (but do not know for sure since I was never told exact brands) the WWMTM's have been compared (with favorable outcome) to those B&W's...

C

Chris,

I thought it was something in the $40K/pr. range, but maybe I'm smokin' crack. 8)

[Brian Bunge]

Well, Chris and his wife stopped by for about 30 minutes yesterday afternoon to take a quick listen to my speakers. I was very pleased to find out that we all had very similar listening tastes, while their knowledge of some of the older 70's rock music was greater than mine. So we broke out some Tool initially and rocked for a few minutes. I then got out my wife's Phantom of the Opera soundtrack and a Dave Matthews Band disc. I like to use Phantom to show off the clarity of the speakers in the vocal range as well as the depth that the speakers can produce with some organ music. Dave Matthews has one of the best drummers around, IMHO, and I love to use this disc to show off the dynamics of the speakers. Also, his cymbal and high-hat work really shows off the tweeters abilities. No harshness here!

My wife came home from Day 12 of her work stint without a day off (we're up to 13 now...) and we had a chance to chat before Chris and Cindy hit the road to continue their trip to Jacksonville. We had a great time listening and talking. Hopefully they can stay longer next time around.

Anyway, Chris posted his thoughts in my big Dayton RS 3-way design thread so I thought I'd copy and paste it here for anyone that is following this thread. I hope you don't mind, Chris.

Oh, since you mentioned some big B&W speakers earlier in the thread, can you tell us what you think of my speakers compared to those? I've never heard any of their products so I'm a bit curious.

Well, I finally got a chance to check out Brian's DIY tower speakers. They are stunning. The craftsmanship is world class, spectacular and over the top excellent. In other words, perfect.

I did not have much time to listen, but what I heard was impressive indeed. They are super smooth sounding, not harsh in any way. In fact, I truly believe they compare closely with the most expensive speakers one can find.

Sound quality and imaging are also world class.

My boss has huge Wilson towers, and I swear that Brian's speakers sound better! Brian's speakers even make Polk's largest towers sound small and colored.

Chris

[---k---]

After hearing that yours are better than some Wilsons, you're thinking about selling them and building something smaller???? :P
(no response needed... better not pollute two threads.)

[Brian Bunge]

Well, they'd still be taller...and have good output down to 20Hz.

[cujet]

Hi Brian and all,

I am not able to compare your speakers with the B+W's. The B+W's were each powered by mono amps of unreal power. They also had a B+W demo disc that had some "non music" "show off" type music on it. In other words, nothing I would ever listen to.

The B+W's were sparkling clean sounding, but what do you expect when you only feed "high freq bell, harp and string sounds" through 'em? I did not get a chance to hear real music on them.

About those HUGE 6 foot Wilson's, My boss' speakers are missing the low freq punch I expected. He has 4 of them in a listening room. Both my pilot buddy and I were not all that impressed with the sound. We both expected more punch. I thought they were clean but,,,,,. I expected rock concert performance. What I got was loud, clean but missing ummph.

Brian is to be worshiped for his skills in cabinetry. I would purchase his speakers today if I had the cash. BTW, I am looking for the cash.

Chris

[Brian Bunge]

Chris,

Interesting. Why in the world would they not run some real music through them? Some dealers are clueless.

Well, if you can come up with the cash they're yours. I've already got the money spent should things happen to work out in both our favors! In the meantime, I'll keeping feeding them daily doses of music and movies.

[---k---]

I got one of B&W Demo DVDs. It has a whole thing on how they are made, blah blah blah, and then a Peter Gaberial live performance and few other performers. I haven't had it in for a while, but it is a good disc for showing off multi-channel audio. You could sign up to receive it for free on the B&W website. Don't know if it is still there.

Don't know why they would be showing off with that section of the disc, if it is the same disc, other than maybe the disc had looped around.

[cujet]

I am considering using 2 ea "Dayton ST305-8 12" Series II Woofers" per cabinet. What do you guys think of that idea?

Chris

[cjd]

Well, a finished product is a synergy. So, sure - if they suit your needs for the low end, they're a solid basic woofer.

What're you going to match them up with is the question!

[Brian Bunge]

Well, their response graph is virtually identical to the dual RS270's in my towers in a similar sized enclosure (based on unibox sims). The biggest difference is that they'll be capable of about 2dB more output throughout that range. This, of course, creates another problem with finding a midrange and tweeter efficient enough to mate well with the increased efficiency of two 12" drivers wired in parallel.

If you want to run them ported then you're looking at 200L+ (7ft^3 and then some) tuned to 25Hz or so.

Any special reason you keep coming back to these woofers?

[cjd]

Midrange coverage shouldn't be that tough - remember we have the mid-woofers in series, not parallel, in the RS WWMTM project. 91-92dB target sensitivity is likely with a basic ~4dB of baffle step.

Thing is, for the money, I'm not sure they're where the value is.

[Brian Bunge]

Ah, yes. I almost forgot about that.

But I'm with you. I think I'd prefer the lower distortion motor design of the RS270's over a couple dB extra efficiency. Especially when the RS270's are a couple of dollars cheaper as well.

[cujet]

cjd said "Thing is, for the money, I'm not sure they're where the value is." I am not hung up on any particular driver. In fact I welcome your suggestions for alternatives.

I think my needs are being refined a bit by this thread, thanks! 110db room spl is my goal. 2ea 12's should do it, no?

7cf enclosures would be OK, remember I prefer sealed.

I suppose I was hoping for someone to suggest a formula something like this:

2ea xyzmouse Woofers
2ea abcxr4Ti Midranges
2ea br549 Tweeters

Reading the various tests posted on the web, there are certainly some favorites and value leaders. (the hope is for suggestions here).

As I mentioned before, I would purchase Brian's speakers in a second if I could. Doing it a little at a time gives me a chance to spread the cost out.

But even with Brian's speakers, I have to wonder about the load on that single tweeter. I suspect that some modification would be required.

Next question: What are the rules on using 2 tweeters? Multiple ribbons are common, but multiple domes are not. Is this due to the nature of the wavelength of higher freq?

Thanks,

Chris

[cjd]

2 tweeters means severe vertical comb filtering - useful perhaps to control dispersion, but... eh. Ribbons already have controlled vertical dispersion so there's less issue, but not no issue. Usually you're looking at a line array though, I believe, when you see multiple ribbon tweeters.

I've hit 110dB. Not happily, ear-plugs solidly in place. Waveguide would help, probably is all that would be required. Hmmm... there's space for a WG in there too.

Not using an existing design simply means you're probably going to have to consider doing your own measurements at the very least. So balance the cost of tools and aggrivation of that.

I have been thinking I may take another pass at a more cost-controlled crossover for the WWMTM's, see what it does. I may decide I should have gone that route in the first place. :P But then, you always learn things along the way that make you wonder about the choices you made in the past.

There are a lot of things to balance when looking at drivers. Just going to a 12 isn't necessarily going to buy you much. Probably lower Fs so sealed response may reach a little deeper. If you're comparing drivers in one family, it's one thing. But the RS270 vs the Series II is a much different comparison - you're looking at size and efficiency against distortion/sound quality. Core vocal range (the "body" of a voice) is covered in the woofers in most designs, just to give you an idea of its importance.

C