these woofers look any good ?

[Audio_Rob]

hey all,

How do these woofers look to you guys, its a clearence price on a canadian website. Tangband 6" woofers, possibly could use them as midbass in a MTM design, and for only 15$ a pop.. take a look and tell me what you think of them, good ? or waste of money..

http://www.acoustic-technologies.ca/specials.html

there the ones at the bottom

thanks

[JonMarsh]

Well, they are inexpensive, but there's not a lot of detailed info. What's the Xmax, for example?

From the FR graphs and impedance curve, it looks like the first cone mode is at about 1100 Hz. Ideally, you wouldn't run them up into that area, but then, you're probably planning an inexpensive system, so the absolute best level of clarity in the mids isn't necessary. The usual minimum crossover for an MTM, to get good response in the crossover region, is a B3- fair amount of parts to do that. What tweeter would you use, and what overall budget?

Me, for all the time and trouble designing and building an MTM takes, I'd rather spend the price of a meal or two out more, and get something with a bit more of a pedigree, like the Dayton RS180. But that may not fit in with your goals or budget. OTOH, were it my money, I'd probably do a good 7" MT before using inexpensive drivers in an MTM. I like a squeaky clean midrange, as well as some decent bottom end.

Why don't you tell us about your plans for these?

[Audio_Rob]

well, my buget is under 400$ canadian, including shipping etc... but not including materials such as wood and finish.

what I have now is jvc minisystem lol...

I want something to replace that and be as good as what im running in the living room, Which isnt fantastic but decent i supppose.. Its a pair of cerwin vega 10" floor standers.. with a sansui integrated amp. I want something thats going to play loud, with a solid bottom end and clear smoth highs and midrange.. I find the vegas to have a bit of a raspy high end and same with the mids.


hope that helps .. btw, i own a table saw, routers, jointers planners, tons and tons of nice tools so cabinet making is no issue.. also Id like to take the Keep it simple aproach to crossover design as I know little about it. Keep in mind this is just my first step into the DIY world, mostly just to get the feel of the things.. Thanks

[Audio_Rob]

ah btw here ar some detaild specs on the drivers posted above

TangBand 6.5" PM WM0640A6-BT


f3 = 84
f10 = 60
vb = 6
0.2
cf3 = 70
fb = 38
fs = 58
xmax = 4.0
vas = 12
re = 6.0
qts = 0.33


You may laugh at this, But i was thinking of doing 2 of those woofers paired with a single or pair of w871 full range drivers.. crossed at 200-500 hz possible ? let the 871 run almost full range, and the 6" woofers take care of the low end ? or is that a horrible idea for a speaker ?

[Paul H]

I have no comments on using a full range speaker, but if you want to do that with a 200-500 Hz cutoff use a 10" or 12" speaker for the bass. Six inch drivers with a 4mm xmax will not provide the low end you'll want.

Paul

[cdwitmer]

You may wish to consider the Cerwin-Vega woofers being closed out by Apex Jr. At 16 ohms and $5 each, they would be good for MTM designs on the cheap.

http://www.apexjr.com/speakerstuff.html

[JonMarsh]

ah btw here ar some detaild specs on the drivers posted above

TangBand 6.5" PM WM0640A6-BT


f3 = 84
f10 = 60
vb = 6
0.2
cf3 = 70
fb = 38
fs = 58
xmax = 4.0
vas = 12
re = 6.0
qts = 0.33


You may laugh at this, But i was thinking of doing 2 of those woofers paired with a single or pair of w871 full range drivers.. crossed at 200-500 hz possible ? let the 871 run almost full range, and the 6" woofers take care of the low end ? or is that a horrible idea for a speaker ?

How do the efficiencies stack up? What I remember is that most of the little full range drivers (I'm more familiar with the HiVi) are NOT very sensitive; it's a tradeoff because of the radiation resistance and achievable BL product with that small a magnet assembly. Even with baffl step comp, the 6's might be too sensitive. But that would solve worrying about the upper mids in the 6's.

~Jon

[whoaru99]

Most Cerwins are very efficient. My old Cerwin D9's (15" woofer w/2 mids & tweet in D'Appolito) are 101db. You need lots of watts and pretty robust speakers to overcome that level of efficiency.

If there is a way, no doubt someone here can, and probably will, provide the needed advice.

[Audio_Rob]

thanks for the input guys, I know itll be hard to match or top my Vegas.. thats what there famous for right ? lots of bass and volume.. i dont need it any louder.. I just want some good SQ and bass at some good volumes.. maybe i should just build some little monitors and pair them up with a good sub.. my budget is a killer though.. 400$ is hard to work with huh

[JonMarsh]

From what you've said additionally, I can see more about your tastes and preferences.

The only way I think I could come close to that budget and do the kind of job I like would be if it were possible to adapt the MT style crossover in the Elaine Marie MkIII using RS180 and 27TDFC to an MTM design; there's about $100 of crossover parts for a pair; the drivers for each cabinet if you went MTM would be ~ $100, leaving the rest for misc parts and construction. See the EM 7.2 post series, specifically the version with Seas 27TDFC and RS180.

I'm not trying to "sell" you anything here, just trying to stear you in a direction for improvied SQ at a reasonable cost to you in parts. That means low distortion drivers that match well (the RS180's and 27TDFC), and a crossover that manages the idiosyncracies of a metal cone woofer at a moderate price. It's even an all-pass 3rd order, so quite adaptable to an MTM.

My high order cauer-elliptic crossovers will sound better, but component cost is higher- between $150 and $200 for the crossover, depending on quality of parts you pick. See Modulaa MTM sticky thread.

~Jon

[Jim85IROC]

John Krutke has a number of designs that you may want to consider. I've never heard these designs (nor any of Jon Marsh's), so I can't comment on sound differences, but due to the more conventional filters that Krutke uses, it'll be more likely for you to find something in your budget, and if you're a beginner, the filter constructon won't be as intimidating either. It might make for a good intermediate until you get the finances/ability/desire to move into one of Jon Marsh's designs.

Krutke's only MTM will cost about $330 US:

http://www.zaphaudio.com/audio-speaker16.html

This metal Seas 2-way will come in below budget:

http://www.zaphaudio.com/audio-speaker17.html

You may also want to consider the Vifa/Dayton MTM kit from Parts Express. You can order all of the parts from PE, and if you click on the pdf manual, you can get a parts list and a crossover diagram:

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=302-940

This design was recently reviewed in Audio Express and seemed to do very well, especially considering the total cost.

[Audio_Rob]

How about the Hi-Vi m8n drivers ? their resonably priced, and i can snatch em off solen and save on shipping etc. posibly those paired with a decent cheap tweeter in a MT ported design. Would the crossover be simple and cheap ? Ive read some threads where people made MTM designs using those woofers and the crossover seemed to be very complex and expensive. If mated up to a nice subwoofer in the future, It wouldnt need to play extremely low. hows that sound ?

[Audio_Rob]

They only problem I have with parts express is shipping.. I checked on those dayton rs180s in the past and to get 4 of them shipping was near 60$... I live north in canada so, I would prefer to order from solen, Who unfortuantly does not deal with dayton.

[Jim85IROC]

The RS180 seems to be such an exceptional driver that even after paying for the shipping charges, you still have a bargain.

But... the Seas metal drivers like the ones in Krutke's 2-way posted above are available from Solen.

[Jam_Master_J]

Hey Rob,
I thought I heard somewhere that Solen doesn't sell HiVi drviers anymore, maybe I heard wrong.

[Audio_Rob]

their website still has them listed, so i hope so

[JonMarsh]

How about the Hi-Vi m8n drivers ? their resonably priced, and i can snatch em off solen and save on shipping etc. posibly those paired with a decent cheap tweeter in a MT ported design. Would the crossover be simple and cheap ? Ive read some threads where people made MTM designs using those woofers and the crossover seemed to be very complex and expensive. If mated up to a nice subwoofer in the future, It wouldnt need to play extremely low. hows that sound ?

Uh, that's my crossover design. ;^)


Those are very nice drivers, IMO, for the money, but you need to get off them pretty quickly by 1200 Hz or so- you need to supress the upper end break up mode quite strongly. The crossovers have one more component than a 4th order L-R. Also, 8's don't have very good upper end dispersion.

When you consider how driver beaming and breakup modes influences the sound of speaker system, the optimum result would be to not run an 8" woofer higher than 1200-1400, and a 7" midwoofer no higher than about 1800. In the past, the best 8" systems were probably three ways. Now, you can make a pretty nice 8" two way WITH the right drivers and crossover... Pairing those M8ns with Seas 27DFC's would be my recommendation for the best performance at lowest cost, though antying up to an RS28a tweeter would be even better, and they'd drop right in in replacment of the Vifa XT25.

OTOH, that's why I suggested a "compromise" design, like my crossover for the RS180/27TDFC MT - but it needs a higher crossover point than the M8a, M8n, or even Seas W22 can handle.

Unfortunately, there's really not any other 7" I know of that's as clean in LF and mid band distortion as the RS180 in that price range. For example, it has double the Xmax of the HiVi M6a, and a cleaner top end, too.

[Audio_Rob]

so a 2way with the hivi 8" drivers probably isnt the best.. but they look so cool ! ;^)

Hrmm

[Audio_Rob]

Ive liked all the 2way 8" speakers ive heard.. It could be that im Pretty new too this stuff and dont really notice the difference between a speaker that beams and one that doesnt. The Genelec, and athena 8" 2ways ive i heard sounded fantastic to me, But then again maybe they corrected the beaming problem in the speakers ? Dont give up on me yet people lol! Im learning alot reading on this forum. Thanks for the input.

[JonMarsh]

Well, you just can't do one with a low parts count crossover. I wrote a three part article for AudioXpress back in 2003, on an M8a based two way design- it's really quite repsectable, and I have a pair here, though mine used the SS9800 tweeter instead of the Vifa XT25 (I tested both, of course, as the goal for the magazine article was inexpensive). That pair will be retro-fitted with the Dayton RS28A tweeter.






But there's no way to do a less expensive crossover unless you really cut corners on component quality; it comes out about $150 dollars.

Variants have been built, MTM versions by several people, for which I re-designed the crossover.

Also, I designed a version a coule of guys have built in a larger enclosure patterend after Avalon designs (I know their original founder, and gave him one of my sets of prototype speakers iwth faceted front panel design in 1982, before he had ever built his first speaker)



They've been built in a design using the RS225 also.





OTOH, with the HiVi drivers, and a pair of Dayton RS28A tweeters, in an optimized conventional tower enclosure (60-70 literes ported, tuned to 25 to 30 Hz), you could have a pretty nice set of speakers at relatively moderate cost and effort (no exotic woodworking) (the FR and distortion target for the original design was the Avalon Eclipse, which sold for many thousands of dollars). The materials, not including enclosures, would run around $400- two HiVi M8a, two RS28A-4, and the crossover parts.


Just some things to think about.

[Audio_Rob]

Interesting, so assuming I use the Hivi woofers, Im going to need to use a rather expensive crossover and a tweeter that dips fairly low, Now does apply to all those hivi drivers ? or just the m8a in particular. It seems as though id be best to shot for the dayton drivers.

Now i ask, why is the crossover so complex and expensive VS other metalic drivers ?

[cjd]

A lot of people compromise the sound by going for simpler crossovers. Jon's crossovers are not overly complex - in many ways careful driver selection allows him to use far simpler crossovers - no multiple notch filters and other odd things that muck up the sound and try to tame the driver where it really shouldn't be operating in the first place.

Of course, they argue that steeper filters compromise the sound more than driver breakup issues. Or they use floppy drivers.

I'm curious where you see large metal drivers being used in a TM with a simpler crossover.

C

[Audio_Rob]

Not saying I have seen them with simple crossovers, It just seems like some crossovers are very complex, I guess its the fact that I know fairly little about crossovers and anything with more the 7 or 8 parts scares me lol.

Ive been reading some stuff though saying that crossovers with lots of parts cant acually compromise sound, and lower sensitivity, due too all the parts and connections that need to be made, lots of people say keep it simple.. its mostly the tub amp guys but, Im not sure if its true.

Could I not just make a simple 2nd order cross over on those HIVI woofers thats crosses over at 1400hz with a good tweeter ?

If not, explain please.

[cjd]

I told you that there are folks that argue every side of this issue. :P

They don't mind their distortion, whether it be from the source or the speakers.

I can not argue that there are compromises all around, but finding drivers that perform to my rules that would allow me to go with a 1st order crossover is impossible - they simply do not exist.

You could put a 2nd order on the M8a. The question is how much would you like the sound. It will not be an optimized setup. It will work, and it may measure flat. To many ears it would sound good.

You would still need a VERY good tweeter or a steep crossover on the tweeter to keep it within a "safe" range (that, or you would only ever listen at low levels).

I can not say that my ears could tell the difference - they might.

Crossover design philosophies vary as much as music preferences, or what you enjoy sitting around and sipping while listening...

C

[Audio_Rob]

ah, I see I see.. so Is that what makes the crossover seem so complicated to me.. You would need one that rolls the tweeter off very fast ? as to not put alot of stress on it playing so low ? that makes sence to me. So overall using the m8a in my budget just doesnt seem worthwhile.. hmm hmm hmm.. i think its the whole 100$+ on a crossover that scares me lol

[JonMarsh]

ah, I see I see.. so Is that what makes the crossover seem so complicated to me.. You would need one that rolls the tweeter off very fast ? as to not put alot of stress on it playing so low ? that makes sence to me. So overall using the m8a in my budget just doesnt seem worthwhile.. hmm hmm hmm.. i think its the whole 100$+ on a crossover that scares me lol

You've got three basic tasks in the crossover-

1 - to roll off the woofer so that the breakup modes and other areas where the cone has energy storaage (resonance) are attenuated- VERY well attenuated, so they dont' color the sound. Provide baffle step compensation, too.

2. Protect the tweeter from low frequencies that would drive it into excursion limited operation and greatly increase the intermodulation and harmonic distortion

3. Blend the response in the transistion region, accounting for phase delay due to acoustic offsets of the drivers, and try to get both smooth on axis amplitude reponse and overall power response (off axis- this behavior is dependent on both the drivers and the characteristics of the crossover in the transistion region.

The crossover is absolutely critical to the performance and tonal balance of the speaker...

Look at the raw response of the RS180 in a small enclosure- not too pretty in some ways, but this remember the plots you see for some of the other drivers are IEC test baffle- i.e., like mounting it in a wall, so there's no change in the resonse going from the baffle load (1/2 space) to full space radiation.





The simplest crossover I've been able to come up with for drivers like the RS180 is this quasi-series 3rd order all pass, which does incorporate cauer-ellpitic elements in the low pass, to attenuate the woofer peaks. Does a very good job of that, too.



The funniest thing I've seen on the 'Guide recently was someone saying that trying to figure out how it worked made their brain hurt... I take that as a complement.



It's about 35% less expensive than my "standard" crossover, but it also doesn't have quite as uniform a power response, and at levels around 95 dB+ may sound a little more strained, since there's more work load on the tweeter, and the upper range of the midwoofer isn't as well attenuated. Contrast the response plot with the "standard" approach I've been using.






This was the measured response well out from the wall and with a relatively short gating window, which reduces the apparent bass level below 200 Hz.



Because of the low crossover frequency and steep attenuation, the response changes very little off axis- at first, it's a little erie to hear a speaker that sounds so uniform out to 60 degrees off axis. Take a look at the Stereophile reviews and see how well most commercial speakers measure at that point- I should say, how most EXPENSIVE commercial speakers measure...

Regardless of what you decide to do with this project, Rob, welcome to the guide and let us know how what you do deicde on turns out. And have fun doing it!

~Jon

[Audio_Rob]

thanks for the input guys, And wow.. crossovers do hurt my brain lol, thats why i wanted to do some small full range drivers with a subwoofer at first, a sub satellite type thing, but.. why start small.. ill do a 2way.. just gotta find one thats right for me lol. ill think ill read up some more on crossover design and how it all works. Trial and error would probably help alot though huh.. maybe thats what i need to do, just design something, then tweak it. well see

[JonMarsh]

Check out the book sections at Madisound, PE, and AudioXpress. Vance Dickason's "The Loudspeaker Design CookBook" is a good place to start, but you might find "Speaker Building 201" by Ray Alden the most fun, and it has a lot of projects.

Trial and error would be a difficult way to get anyplace useful, IMO- would involve a lot of frustrating wandering around in the woods, so to speak. What we do here isn't trial and error, as you might imagine, but then I'm an EE with 30 years experience. It proceeds from physics and having a sound goal... pun intended.

[cjd]

Trial and error would be a difficult way to get anyplace useful, IMO- would involve a lot of frustrating wandering around in the woods, so to speak.

With the books and reading the forums though, it can teach a LOT that may be otherwise difficult to wrap your mind around fully.

For something like this, I recommend grabbing some really cheap drivers and experimenting. PE has data files published that you can use with the many excellent free tools at the FRD Consortium. But understanding all the aspects will take some time - potentially years. And you have to understand that you are investing the time in a hobby that will not go away at that point.

If you want to build something now and don't know that you want to have the problem of trying to figure out what to DO with ALL those projects down the road, I highly recommend picking an established project and going with it. Don't worry if you understand all the why's - if you're still curious, you can figure that out later (and maybe still find yourself with too many speakers for your house!)

There are designs out there that Jon wouldn't consider acceptable. His standards are, I think, way out there. When he designs something "cheap, so it may sound strained above 95dB" it probably is still going to do better in many respects than other designs out there using the same drivers.

Remember too - your ear enjoys what it is used to in a very big way.

Given the frequency that I listen at 95dB levels... (I find that when I listen to symphonies, it's usually a 40-75dB range, with the core in the mid 60dB range - when I want loud, that might push to 55-90dB, with the core in the mid 80dB range).

C

[DeanP]

Audio_Rob

I've been reading this guide for about a year or so and have learnt alot froms these gurus. I have always wanted to make some of the nice speakers they have designed here but funds are always lacking for them. Someday I will build a set "of the Day on the forum" and I know that they will be comparable to thousand $+ speakers but for mere "pennies".
I own Athena speakers now and I think they sound just fine, but the crossover is just a basic second order, so the speakers/crossovers they design here would probably put them in the very high end retail speakers.
And to build something comparable to the Athena would be about
$50-$75Can. for drivers and about $20Can. for crossovers parts, so imagine a highly designed crossover for retail speakers, such as the M8as designed by "Jon Marsh", how much they would be on the retail street.
I hope what I said makes sense to you. What it boils down to is if the Athenas sound good to you, then look for a crossover design that isn't too "complicated", build them and then wait for the "upgrade bug"(which will be while you are building the set you went with!)
BTW Go and listen to some high end B & Ws or Mirages and then ask yourself "Do I like these better?", if you answer yes, then build something these guys designed here for about 1/5 the cost!

[Audio_Rob]

well... to be blunt.. i want to build some 2way towers with the Hivi m8a's, Dont know why, I just LOVE the look of them. Im a bit of a carpenter and take pride in how my projects look. I really want to build a speaker that looks stunning, not something with plain old black dayton drivers ;^) .. and at the same time, I want a solid sound.

Could i build a set of speakers with the m8s's with a crossover thats basic, and upgrade it later ? keep in mind people, at this point.. 80% of my music comes from a JVC minisystem, and an 80$ set of computer speakers.. I dont think it should be to hard to build something better on a tight budget

I have a fine amp to power them for now, a classic Sansui 417 integrated amp.. It gets lots of praise online for being very clean sounding amp.

[Audio_Rob]

perhaps if I where to go with a pair of the M6a or M5a drivers ? could that allow for higher simpler crossover ? using 2 6" drivers so equal to the radiating area of an 8" correct ?

[Audio_Rob]

hmmm... After browsing the forum some more, Ive stumbled across a very nice looking design by john, using the m8a, in a really funky looking enclosure with lots of nice angles on it. I believe there was mention to an Arvo copy or something in it.. A question to John, What would be the cost of drivers and crossover parts to build those ? also, What tweeter is used ? and is it available through solen ? if not what tweeter could replace it ? those speakers are definatly peaking my interest

[Audio_Rob]

nm sorry gave the above some re-reading.. about 400$ .. i may have to give that shot. In comparison to my vegas I have, how loudly will the m8a's play ? and how much bass will the put out ? im assuming a lot less, considering the vegas have a 96db sensitivity and use 10" woofers VS 8".. but thats ok, as long as they smoke them for SQ

[ThomasW]

Could i build a set of speakers with the m8s's with a crossover thats basic, and upgrade it later ?

Unfortunately no that won't work and is a waste of money in the long term.

perhaps if I where to go with a pair of the M6a or M5a drivers ? could that allow for higher simpler crossover ?

Again unfortunately no, metal cone drivers require complicated crossovers.

using 2 6" drivers so equal to the radiating area of an 8" correct ?

Close but that doesn't mean you can make a substitution and use 2-6" and keep the same crossover design.

using the m8a, in a really funky looking enclosure with lots of nice angles on it.

That is the M8a-ta design you can find a VERY long thread about it. From a woodworking standpoint that is the single most complicated speaker yet designed. Certainly not a first project for a noobie.

In comparison to my vegas I have, how loudly will the m8a's play ? and how much bass will the put out ? im assuming a lot less

No they won't play as loud as your Vegas but yes the sound quality will be much better