Newbie question

[wyomoose]

I am thinking about buying a set of B&W 602 speakers. But I am curious if I could build something similar for less money plus I would get to say I built it. Does any one know of any kits I could buy to get a close sound to B&W?
Thanks
Moose

 

[mike c]

err, unless you had "inside info" on whats inside the b&w 602 (especially the kevlar driver)
you might not be successful in imitating the 602.

although making speakers in the first place isn't as easy as making a subwoofer box, unless you actually know what you are doing.

my advice is to just buy the 602 and enjoy.

 

[annunaki]

B&W makes an excellent speaker. One would have to admit their research and development team is, arguably, one of the best in ANY field. They have excellent resources. It would be difficult to build a set of speakers (without much speaker building experience) that will give you similar sound to the 602. B&W's speakers (300, 600, and 700 series) are an excellent example of "trickle down technology".

You could try what I did. That is, find a great pair of B&W in-walls on the cheap and built a proper enclosure for them. Do a search in this forum, you should be able to find them. They are now my reference monitors (Signature 7 SE).

 

[Swerd]

First of all, B&W 602s at what price? And what version are they, S2, S3?

I found a fairly well detailed review of the S2 version of the 602s that provides some detail of their design. From a DIY point of view, its pretty good. http://www.audioxpress.com/reviews/media/AX201DA.pdf. The author, Joseph D'Appolito, is a well known authority in speaker design.

The 602s are a straight forward 2-way ported design with a 7" Kevlar midwoofer and a 1" aluminum dome tweeter. The crossover point is either 4 kHz as stated in the table, or 3.5 kHz as shown in figure 3 and in the author's text. Whether it's 3.5 or 4 kHz, both may be somewhat high crossover points for a 7" driver. More about this below.

While B&W speakers in general have a very good reputation, they are expensive. Note that the individual drivers that B&W uses in these speakers are not identified, and may not be available to buy for DIY use.

The 602s do have some compromises or flaws in their design. The reviewer points out several that I think might be audible. In the 1st paragraph of the 2nd dolumn, the author says "Response shelves up above 7 kHZ by 3 dB. There is also a broad response peak of about 2 dB centered on 100 Hz, and a sharp resopnse dip of 3-5 dB centered on 6 kHz."

Lower down in that same column in the 3rd paragraph, he says, "Notice that the tweeter response is quite smooth. The woofer that is out of phase with the tweeter at this point causes the sharp system response dip at 6 kHz. B&W claims that the crossover is fourth-order, but it is clear that the woofer response is not falling off anywhere near that fast in the first octave above crossover. I suspect that the woofer response peaks in this frequency region."

These features can be seen in figures 2, 3, 4, and 7. Note in figure 4 that the peaks around 400-700 Hz and at 7-8 kHz ring for a long time.

• The broad 2 dB response peak centered on 100 Hz is a feature common to many ported designs that overemphasize bass in that region. In the case of the 602s, it's mild. I've seen worse. Just the same, it could be fixed by changing the port tuning frequency.
  
  
• The 3 dB response shelf above 7 kHz is a simple problem of tweeter response that is too hot. It could be easily smoothed out.
  
  
• The dip at 6 kHz, as the author explained, is probably due to a response peak (maybe a breakup peak) of the woofer that is not sufficiently filtered out by the crossover. Combined with the rising response above 7 kHz, these two features, in my opinion, may be responsible for the characteristic bright sound of B&W speakers. It could be solved by adding a notch filter around 7-8 kHz, or by a complete redesign of the crossover to a lower frequency. This may require using a different tweeter.

So to get back to your question, is there a DIY kit that is a clone of the B&W 602? No. But depending on the price, you can probably do a lot better. Have a look at these two designs:

http://www.rjbaudio.com/Asterion/asterion.html

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

 

[annunaki]

To my understanding, B&W manufactures ALL of their own drivers. None of them are available for individual sale.

 

[Swerd]

Your original question did ask for kits, and I suggested some DIY designs not available in kit form. For those two designs you would have to build or buy cabinets, and layout and assemble the crossovers on your own. Its not that difficult, but if you have not done it before, it can seem like a big obstacle.

Here is a kit for a 2-way that includes premade cabinets, and preassembled crossovers. It's expensive, $710 a pair ($430 a pair without cabinets), but I still don't know what price you are facing for the B&W 602s. For DIY speakers, it is common to assume that an equivalent quality speaker will sell retail for 3 to 5 times the DIY price.

Madisound sells the kit called the SA-1. http://www.madisound.com/SA-1.html

See also http://www.selahaudio.com/id46.html

The SA-1 is designed by Rick Craig who has his own custom made speaker company called Selah Audio. I don't know him personally, but he is known and respected by some very good amateur DIY designers that I have met. I haven't heard this design, but I have heard others that use the same woofer. I think they are the best mid-woofers in their price range.

You might try asking your original question about kits that sound similar to B&W 602s at the Madisound Audio Discussion web site http://www.madisound.com/cgi-bin/discuss.cgi. A lot of good DIY builders post there, including Rick Craig. If you ask how well the SA-1 compares to the B&W 602, you will probably get an answer directly from him.

 

[Johnd]

Agreed. B&W has a great reputation, at the high end of r&d, is pricey, and i generally like their sound. My friend has a pair of 602's that he uses as mains (on his ht system, he has 703's for his sound system). I like their sound, and they are incredibly accurate, with one caveat...the 602's are totally devoid of bass. Good luck mimicking, or even coming close to their sound with any diy kit. I mean that honestly (no sarcasm).

 

[annunaki]

Johnd,

I have to disagree with you on the bass aspect of the DM602. I have listened to them many times and they always seemed to have a good amount of bass. Granted they will not go extremely low, but that is what a good sub woofer is for. B&W definitely is not renowned for their bass response but I believe the bass to be quite accurate, if ever so slightly, subdued. I would not say that they were devoid of bass though.

 

[Swerd]

The question of whether the 602s have enough bass response or not depends on several things.

Room Location - A speaker's response, below 200 Hz is heavily dependent on reflections and standing waves caused by the reflecting surfaces in the room. When you heard the 602s, they may have been in a poor location for bass.

What are you used to - Other speakers you are accustomed to listening to may have stronger bass response. This will definitely influence your impression.

Amplifier power - Even though B&W says these speakers have a sensitivity of 90 dB and rates them at a nominal 8 ohm impedances, their minimum impedance is 4.3 ohms. If you look at figure 1 in http://www.audioxpress.com/reviews/media/AX201DA.pdf, you'd see that 4.3 ohms is more like the norm than 8 ohms. If Johnd heard the 602s driven by an amplifier without enough power, then he would notice it by the lack of bass authority.

 

[Johnd]

Devoid of bass was an exaggeration to drive my point home. And, yes, placement can augment the bass, or entirely strip it of lfe. Oops, there I go again.

 

[wyomoose]

602 reply

Ok the 602's are around $600 I haven't tried to deal on them yet but I think I can get them for $550. They would be brand new so I think they are the S3's.
I currently have a set of Def tech Gems which have zero bass and I like them but I like the 602 or the paradigm studio 20 sound a lot better. Even the two sound different from each other out of the two I like the 602's the best. The idea of building a speaker intrigues me. I have a friend that built a pair of Lukwitz ( I may have mispelled it I see his name in some of the speakers you guys recommended) speakers they sounded awesome they were of course like 2300 to build. But after I heard them I thought I might try it. The trouble I see with building your own is you don't know what you are getting until it is built unless you can find a pair and listen to them before hand and then I think it might be different. Thanks for your guys help

 

[Swerd]

wyomoose

I think $600 is the retail price for the 602s. If you can get them for $550, that's good. I don't think you'll find new B&W speakers at a much lower price.

If you like the idea of building your own speakers, I certainly want to encourage you. Unless you want to spend $2300, forget your friends speakers - were they Linkwitz Orions? http://www.linkwitzlab.com/orion_us.htm They are without comparison, but require built-in amplification, active crossovers, and I would not consider them for a first time project.

Because you like the sound of the B&W 602s, I think you may like the sound of metal speakers. Metal coned woofers share many of the sound qualities that Kevlar fiber woofers (like in the B&Ws) have. They both are said to have a more "detailed sound" that comes from reproducing a music wavefrom more accurately than the more flexible paper or plastic speaker cones. A stiffer cone, such as metal, maintains pure piston-like movement much higher in frequency than a poly or paper cone. The problem comes at frequencies an octave or two above the crossover point, where the speaker cone no longer acts like a piston and the sound begins to "break up". Stiffer cones suffer from huge noisy break up peaks. The crossover must successfully filter them out. Many commercially made metal speakers don't do this well. As a group, they suffer from a kind of upper midrange harshness that often leads to listener fatigue. Even the Kevlar B&W 602s suffered from a bit of this. In the review I mentioned, there was a dip at 6 kHz followed by a peak at 7-8 kHz. The reviewer said this comes from an inadequately filtered break-up peak of the Kevlar woofer.

The Seas 2-way design by John Krutke http://www.zaphaudio.com/audio-speaker17.html is one of the best metal 2-way designs around. The designer is well aware of the inherent problems of metal speakers, and took great efforts in his crossover to solve that. His design uses a 0.5 ft³ (14 liter) cabinet with a vent port tuned to 42 Hz. The cost is $435 a pair including premade cabinets. Without cabinets, the parts are about $300 a pair. Using the usual 3 to 5-fold factor of comparing DIY speaker costs to retail costs, the Seas 2-way would be comparable to retail speakers costing $900 to $1500.

How good are your woodworking abililities? Can you make your own cabinets from ¾" MDF? Detailed drawings showing the cabinet dimensions are buried somewhere in the web site. To flush mount these you must make counter-sunk circles on the front baffle. Do you have access to a router and a circle cutting jig? If not, you can buy premade cabinets that are very well constructed, veneered and finished for about $145 a pair.

John Krutke's web pages can be kind of longwinded if you want to find the bare details. If you are interested, I can email you a file containing diagrams, drawings, and a detailed parts list that is much easier to read.