Need advice converting B&W 602 s2 into 3-way
Hey all holy audio folk!
Looking to build HQ 3-way speakers out of my B&W 602 s2 speakers and need advice or ideas from anyone that's tried doing this before.
Here are list of current plans;
Cabinet construction;
-Marine ply front rear baffles or mdf
-Granite black galaxy side panels
-Pine frame with internal matrix bracing
-Bitumen sound deadening material throughout
-All drivers time aligned
Separate cabinets for tweeter,mid,woofer;
-1" B&W tweeter in free space above mid with plastic taper tube removed and TL sealed enclosure as close to mid as possible.
-7" B&W mid in sealed 11 litre enclosure with matrix bracing,bitumen damping,pyramid acoustic foam
-10" dual woofer push pull sealed 75-90 litres enclosure with one driver facing front close to mid other driver directly behind on rear baffle magnet on outside,matrix bracing,bitumen damping,pyramid acoustic foam.
Crossover details:
-aiming for 1rst order (if can get away with it)
-350hz and 3khz
-HQ components,low dcr inductors self wound with 3mm thick copper air core
-will test with cheap components first before settling on exact crossover points!
Woofer driver specs;
-10" Kevlar/Paper -
-150wrms
-8ohms
-88db (1w @ 1m)
-Qms:2.41
-Qes:0.54
-Qts:0.44
-Vas:138.3 Litres
-Fs:25hz
-Tuning frequency:30hz
-Recommended box:75 litres ported
I've used Bassboxpro for simulations which indicate bass response at -3db@49hz and -6db@36hz.
I've provide a link on B&W 602 s2 review with specs on response which seems to show sensitivity @87.9db approx.
http://www.audioxpress.com/reviews/media/AX201DA.pdf
Questions;
-What do you guys think of this design will it work,what problems do you see?
-Using push pull design should bring sensitivity back to 88db counting 6db baffle loss to keep even with mid/tweeter response,is this right?
-The B&W tweeter has 4ohms and woofer has 8ohms on back of driver but I'm thinking woofer is actually 4ohms judging specs in link,trying to get away from using any zobel in crossover?
-Will I lose sensitivity with mid in sealed enclosure crossed @350hz?
Sorry if post is all over the place,don't really do much posting anywhere and this is my first post here!
Welcome and appreciate any thoughts,suggestions,constructive critasisim,or help from anyone who has done project similar.
Thanks.
Hey all holy audio folk!
Looking to build HQ 3-way speakers out of my B&W 602 s2 speakers and need advice or ideas from anyone that's tried doing this before.
Here are list of current plans;
Cabinet construction;
-Marine ply front rear baffles or mdf
-Granite black galaxy side panels
-Pine frame with internal matrix bracing
-Bitumen sound deadening material throughout
-All drivers time aligned
Separate cabinets for tweeter,mid,woofer;
-1" B&W tweeter in free space above mid with plastic taper tube removed and TL sealed enclosure as close to mid as possible.
-7" B&W mid in sealed 11 litre enclosure with matrix bracing,bitumen damping,pyramid acoustic foam
-10" dual woofer push pull sealed 75-90 litres enclosure with one driver facing front close to mid other driver directly behind on rear baffle magnet on outside,matrix bracing,bitumen damping,pyramid acoustic foam.
Crossover details:
-aiming for 1rst order (if can get away with it)
-350hz and 3khz
-HQ components,low dcr inductors self wound with 3mm thick copper air core
-will test with cheap components first before settling on exact crossover points!
Woofer driver specs;
-10" Kevlar/Paper -
-150wrms
-8ohms
-88db (1w @ 1m)
-Qms:2.41
-Qes:0.54
-Qts:0.44
-Vas:138.3 Litres
-Fs:25hz
-Tuning frequency:30hz
-Recommended box:75 litres ported
I've used Bassboxpro for simulations which indicate bass response at -3db@49hz and -6db@36hz.
I've provide a link on B&W 602 s2 review with specs on response which seems to show sensitivity @87.9db approx.
http://www.audioxpress.com/reviews/media/AX201DA.pdf
Questions;
-What do you guys think of this design will it work,what problems do you see?
-Using push pull design should bring sensitivity back to 88db counting 6db baffle loss to keep even with mid/tweeter response,is this right?
-The B&W tweeter has 4ohms and woofer has 8ohms on back of driver but I'm thinking woofer is actually 4ohms judging specs in link,trying to get away from using any zobel in crossover?
-Will I lose sensitivity with mid in sealed enclosure crossed @350hz?
Sorry if post is all over the place,don't really do much posting anywhere and this is my first post here!
Welcome and appreciate any thoughts,suggestions,constructive critasisim,or help from anyone who has done project similar.
Thanks.
I think you should start by giving us the specs including crossover points, driver type and dimensions, port dimensions, and cabinet dimensions of the standard B&W 602 S2 first, then from there explain the modifications you are going to make. Explain what you are adding to the stock units.
Now I could search the internet and find all this out for myself, but it would be so much easier if you just gave us the information.
Start with what you have, then tell us where you want to go.
Steve/bluewizard
Now I could search the internet and find all this out for myself, but it would be so much easier if you just gave us the information.
Start with what you have, then tell us where you want to go.
Steve/bluewizard
Hi Steve,
What I'm trying to do is get rid of 602 box completely,use tweeter and mid driver in new 3-way cabinet time aligned array.
When I originally purchased them,I wanted B&W 603/604 s2 but had no room at the time so chose 602 instead and now there hard to find so I've decided to try convert these to something better.
-Basically tweeter will be in seperate sealed enclosure maybe TL type.
-Mid range woofer in sealed enclosure of approx 11 litres to 22 litres.
-Bass woofer will be in sealed enclosure dual 10"push pull of 65 or 90 litres.
Dimensions :H727.5 x W277.9 x D449.6 for 90litre bass enclosure.
or H650.8 x W248.6 x D402.2 for 65litre bass enclosure. 30mm baffles and 30mm side panels.Further adjustments is size will be made for bracing.
Crossover points will be approx 350hz and 3khz approx.
B&W 602 s2 specs:
The 602 box has 22 litre flared ported box.
Port size is 50mm diameter 95mm length.
2-way 4th order crossover(1rst order on woofer 3rd on order tweeter)
7" woven kevlar mid driver
1" metal dome tweeter
Frequency response 52hz - 20khz +/-3db
Sensitivity 90db
Impedance 8ohm (minimum 4.3)
Power handling : 25-120wrms
Dimensions : H490mm x W236 x D306
I provided link of detailed measurements take on B&W 602s2 in post.
My aim is for sound quality so choosing for sealed or push pull cabinet designs no ports,overall similar look to early B&W 801/802 series 1.
Thanks,
Steven.
What I'm trying to do is get rid of 602 box completely,use tweeter and mid driver in new 3-way cabinet time aligned array.
When I originally purchased them,I wanted B&W 603/604 s2 but had no room at the time so chose 602 instead and now there hard to find so I've decided to try convert these to something better.
-Basically tweeter will be in seperate sealed enclosure maybe TL type.
-Mid range woofer in sealed enclosure of approx 11 litres to 22 litres.
-Bass woofer will be in sealed enclosure dual 10"push pull of 65 or 90 litres.
Dimensions :H727.5 x W277.9 x D449.6 for 90litre bass enclosure.
or H650.8 x W248.6 x D402.2 for 65litre bass enclosure. 30mm baffles and 30mm side panels.Further adjustments is size will be made for bracing.
Crossover points will be approx 350hz and 3khz approx.
B&W 602 s2 specs:
The 602 box has 22 litre flared ported box.
Port size is 50mm diameter 95mm length.
2-way 4th order crossover(1rst order on woofer 3rd on order tweeter)
7" woven kevlar mid driver
1" metal dome tweeter
Frequency response 52hz - 20khz +/-3db
Sensitivity 90db
Impedance 8ohm (minimum 4.3)
Power handling : 25-120wrms
Dimensions : H490mm x W236 x D306
I provided link of detailed measurements take on B&W 602s2 in post.
My aim is for sound quality so choosing for sealed or push pull cabinet designs no ports,overall similar look to early B&W 801/802 series 1.
Thanks,
Steven.
Sorry forgot to add,
I have B&W 602s2 speakers and all building materials needed(granite,marine ply,pine timber boards,bitumen sheets,pyramid foam,copper wire for inductors).
I do not have bass drivers as yet but the 10" ones mentioned are ones looking at but open to other driver recommendations and designs.
Thanks,
Steven.
I have B&W 602s2 speakers and all building materials needed(granite,marine ply,pine timber boards,bitumen sheets,pyramid foam,copper wire for inductors).
I do not have bass drivers as yet but the 10" ones mentioned are ones looking at but open to other driver recommendations and designs.
Thanks,
Steven.
When you say 'mid driver', I assume you mean 'mid-bass' driver. The original speakers were 7" bass (midbass) and 1" dome tweeters(?).
The height dimension of 460 mm or 19.3 inches, indicates that these are some reasonably large bookshelf speakers.
To this original speaker, you want to add some combination of 10" low bass drivers?
Any chance you know the current crossover of the B&W's?
I confess, I'm not an expert on speaker building. Being dirt poor, I'm more of a cut and hack designer.
I personally think your plan for the low bass end, being 2x 10" push/pull woofers, is a bit of overkill. But, on the other hand, if well balanced, it could certainly work.
One approach is to treat this like a half-way system, as in a 2.5-way system. Use the current crossover for the 7" and 1", get them in the new cabinets, run a low end frequency sweep, and find the baffle step. This could also be determined with simulations using various software packages. Others here know far more about this than I do.
At some point in the frequency sweep, the response should drop by 6db and level off again, usually in the 100hz to 300hz range. That 6 db drop represents the baffle step. The center of the falling slope of that drop off should be your midbass to low-bass crossover.
Below the step, both mid and low are playing, above the step, the low-bass fades out.
Another approach is to simply treat it like a standard low-bass, mid-bass, high 3-way speaker. But you can't ignore baffle step. It would be nice if the low-bass were still coordinated with the baffle step to assure flat smooth response.
The difference between this and the 'half-way' system and this full 3-way is, of course, that the is a full crossover between low-bass and mid-bass.
Another alternative, is to treat the push/pull 10" as a separate system, similar to a subwoofer. Leave the existing system as is, in the new cabinets or in separate cabinets, and add the low-bass to it. In this case, I would explore using a separate amp to power the low-bass end.
The difference between this and a subwoofer would be a passive crossover and likely a higher crossover frequency. Plus it is only likely to function down into the low 30's, rather that sub 20hz as some subwoofer claim to do.
My central point is, I would keep the mid-bas, tweeter section as close to what it currently is as possible to eliminate complication in the design. Though, you seem to have design tools to aid you, I think the easier you can make it, the better the end results will be.
Further, do you really know the T/S parameters on the B&W speakers. You will probably need that to make your design and simulation software to work.
If is possible to buy a Dayton woofer tester for something like £100, and while not the most sophisticated software, it will give you all the design parameters you need to accurately design proper cabinets for the mid-bass section.
Again, I'm admittedly in over my head in the details of this design, but conceptually, I hope I have helped, or at least opened the door to more discussion.
Steve/bluewizard
The height dimension of 460 mm or 19.3 inches, indicates that these are some reasonably large bookshelf speakers.
To this original speaker, you want to add some combination of 10" low bass drivers?
Any chance you know the current crossover of the B&W's?
I confess, I'm not an expert on speaker building. Being dirt poor, I'm more of a cut and hack designer.
I personally think your plan for the low bass end, being 2x 10" push/pull woofers, is a bit of overkill. But, on the other hand, if well balanced, it could certainly work.
One approach is to treat this like a half-way system, as in a 2.5-way system. Use the current crossover for the 7" and 1", get them in the new cabinets, run a low end frequency sweep, and find the baffle step. This could also be determined with simulations using various software packages. Others here know far more about this than I do.
At some point in the frequency sweep, the response should drop by 6db and level off again, usually in the 100hz to 300hz range. That 6 db drop represents the baffle step. The center of the falling slope of that drop off should be your midbass to low-bass crossover.
Below the step, both mid and low are playing, above the step, the low-bass fades out.
Another approach is to simply treat it like a standard low-bass, mid-bass, high 3-way speaker. But you can't ignore baffle step. It would be nice if the low-bass were still coordinated with the baffle step to assure flat smooth response.
The difference between this and the 'half-way' system and this full 3-way is, of course, that the is a full crossover between low-bass and mid-bass.
Another alternative, is to treat the push/pull 10" as a separate system, similar to a subwoofer. Leave the existing system as is, in the new cabinets or in separate cabinets, and add the low-bass to it. In this case, I would explore using a separate amp to power the low-bass end.
The difference between this and a subwoofer would be a passive crossover and likely a higher crossover frequency. Plus it is only likely to function down into the low 30's, rather that sub 20hz as some subwoofer claim to do.
My central point is, I would keep the mid-bas, tweeter section as close to what it currently is as possible to eliminate complication in the design. Though, you seem to have design tools to aid you, I think the easier you can make it, the better the end results will be.
Further, do you really know the T/S parameters on the B&W speakers. You will probably need that to make your design and simulation software to work.
If is possible to buy a Dayton woofer tester for something like £100, and while not the most sophisticated software, it will give you all the design parameters you need to accurately design proper cabinets for the mid-bass section.
Again, I'm admittedly in over my head in the details of this design, but conceptually, I hope I have helped, or at least opened the door to more discussion.
Steve/bluewizard
I don't mean to sound negative, but I personally wouldn't bother with granite side cheeks and push-pull woofers. It's going to make it a hard and expensive project. The granite would also negate the plywood's good properties to some extent. It'd be so much easier to just make a nice plywood box and put a good quality 12" woofer in there. Sealed might also not sound bassy enough if you like the B&W sound. How about a de-tuned port? This could go very low and without the typical boomy sound associated with ports. Just thoughts.
I used to own the DM602 S2 and it was a very good speaker at this price point. The 7" kevlar mid/bass sounded wonderful. The crossover point, like on most B&Ws, is 4Khz.
I'd, again - personally, not touch the upper crossover at all, other than to upgrade the caps and white coffin resistors. My recommendation would be Mundorf Supreme caps and Kiwame resistors. Then just add an active crossover between the "602" part and the woofer part. As suggested this could be at baffle step frequency, or just below like B&W would - ~200hz.
This could be a wonderful speaker. Good luck!
Simon
I used to own the DM602 S2 and it was a very good speaker at this price point. The 7" kevlar mid/bass sounded wonderful. The crossover point, like on most B&Ws, is 4Khz.
I'd, again - personally, not touch the upper crossover at all, other than to upgrade the caps and white coffin resistors. My recommendation would be Mundorf Supreme caps and Kiwame resistors. Then just add an active crossover between the "602" part and the woofer part. As suggested this could be at baffle step frequency, or just below like B&W would - ~200hz.
This could be a wonderful speaker. Good luck!
Simon
Hmmm.......
A commercial 2-way into a 3-way .....
One obstacle could be the tweeter is set to the sensitivity of a
baffle stepped bass/mid, (common in commercial designs, the
tweeter magnet is only as big as it needs to be) and this means
that you must keep all the baffle step in the bass/mid unit.
In other words a sub / satellite system. (IMO a genuine 3-way
involves both bass and mid drivers in the BSC arrangement).
I would suggest the subwoofer route is more sensible / flexible.
Make new (sealed) beefed up cabinets if you like keeping the
top section of the front baffle. Do not discard the tweeter tube.
A small standmounted cabinet is far easier to make sound good
than a large floorstander. Subwoofers are relatively easy to make
that operate below all panel resonances. A 4 ohm plate amplifier
with 2 8ohm drivers in seperate cabinets gives position flexibility.
Regarding a 3-way with 6.5" and 1" see :
http://www.deadwaxcafe.com/vzone/david/david.htm
/sreten.
Granite side cheeks might work if attached by an intermediate
damping layer that is selected for restrained damping mode.
A commercial 2-way into a 3-way .....
One obstacle could be the tweeter is set to the sensitivity of a
baffle stepped bass/mid, (common in commercial designs, the
tweeter magnet is only as big as it needs to be) and this means
that you must keep all the baffle step in the bass/mid unit.
In other words a sub / satellite system. (IMO a genuine 3-way
involves both bass and mid drivers in the BSC arrangement).
I would suggest the subwoofer route is more sensible / flexible.
Make new (sealed) beefed up cabinets if you like keeping the
top section of the front baffle. Do not discard the tweeter tube.
A small standmounted cabinet is far easier to make sound good
than a large floorstander. Subwoofers are relatively easy to make
that operate below all panel resonances. A 4 ohm plate amplifier
with 2 8ohm drivers in seperate cabinets gives position flexibility.
Regarding a 3-way with 6.5" and 1" see :
http://www.deadwaxcafe.com/vzone/david/david.htm
/sreten.Granite side cheeks might work if attached by an intermediate
damping layer that is selected for restrained damping mode.
Cheers on replies,
Basic aim is a TMW full 3-way speaker with 1"dome high,7"mid range,2x10"bass push pull.
B&W 602 s2 is large bookshelf speaker with 4th order crossover @4khz.
My new proposed crossover 350hz & 3khz approx complete 1st order.
Reason behind using dual 10" push pull is sound quality,smaller overall speaker foot print size,better depth than smaller drivers,plus no need for speaker stands.
Haven't done any major tests yet but had planned too just wanted advice or council first before embarking,been contemplating these mods for while now.
I do not have t/s parameters on B&W 1"tweeter or 7"mid bass driver yet but if anyone has would be grateful for any help!
Although I know already I found your explanation on baffle step excellent Steve/Bluewizard,do appreciate any advice!
Baffle step seems to be between 350-550hz according to review which is why I chose 350hz approx but may end up different with driver tests in sealed enclosure.
I'll try to knock up some dummy boxes do tests and driver measurements soon to know for sure before buying 10" bass drivers.
Also,was considering using 60-80hz roll off for rear 10" pulling bass driver,read that it can improve bass response in bottom end and help with crossover mid range blend?
I'm only looking for clean extension to mid 30hz upwards hopefully without equalization needed and will be using 300watt@4ohm mono block amplifiers on each,but may even opt for active/passive option for bass depending on tweeter/mid range test results.
I already have subwoofer that I'm currently about to build to compliment bottom end,15" type r Alpine with 600watt class d amp module,though need to construct cabinet yet which will be 100litres approx.
I will post pictures and info as I begin construction.
Thanks,
Steven
Basic aim is a TMW full 3-way speaker with 1"dome high,7"mid range,2x10"bass push pull.
B&W 602 s2 is large bookshelf speaker with 4th order crossover @4khz.
My new proposed crossover 350hz & 3khz approx complete 1st order.
Reason behind using dual 10" push pull is sound quality,smaller overall speaker foot print size,better depth than smaller drivers,plus no need for speaker stands.
Haven't done any major tests yet but had planned too just wanted advice or council first before embarking,been contemplating these mods for while now.
I do not have t/s parameters on B&W 1"tweeter or 7"mid bass driver yet but if anyone has would be grateful for any help!
Although I know already I found your explanation on baffle step excellent Steve/Bluewizard,do appreciate any advice!
Baffle step seems to be between 350-550hz according to review which is why I chose 350hz approx but may end up different with driver tests in sealed enclosure.
I'll try to knock up some dummy boxes do tests and driver measurements soon to know for sure before buying 10" bass drivers.
Also,was considering using 60-80hz roll off for rear 10" pulling bass driver,read that it can improve bass response in bottom end and help with crossover mid range blend?
I'm only looking for clean extension to mid 30hz upwards hopefully without equalization needed and will be using 300watt@4ohm mono block amplifiers on each,but may even opt for active/passive option for bass depending on tweeter/mid range test results.
I already have subwoofer that I'm currently about to build to compliment bottom end,15" type r Alpine with 600watt class d amp module,though need to construct cabinet yet which will be 100litres approx.
I will post pictures and info as I begin construction.
Thanks,
Steven
Interesting... with a sub to sit below I'd aim for 40hz extension on your 3-ways. And again I'd like to urge you to leave B&W's excellent crossover alone. I can't see how it's possible to improve on it. These are multi-award winning speakers from the biggest speaker maker in the world. This is not an area you can improve, other than by upping passive component quality.
Areas you can improve on greatly are in cabinet quality and bass extension and dynamics, by going 3-way.
Although baffle step will kick in at about 400hz on paper, B&W haven't had a problem making a full-sounding 2-way there, so the woofer element in your design doesn't need to be more efficient than the upper sections . You could end up with bass that is too efficient, which is another good reason for going active on the bass. If you need more reasons, here you go - the power handling and max ouput level of the speakers will be much higher by going active between bass and mid, and distortion reduced. It also means you have no passive parts to ruin damping of the woofer(s) so they'll sound tight and clean - and no large inductors to buy, as you'd need in a good 3-way.
Push-pull isobaric is a fairly pointless technology, it potentially doubles woofer cost, adds complexity and does what? Slightly reduces distortion. The main benefit is allowing you to use drivers that were designed for a larger box than you can accommodate. This is a moot point if you buy the correct woofer in the first place. Please at least consider this before buying the woofers.
Also, if you decide to go passive, consider quite a small closed box, enhanced by Graham Maynard's T-bass circuit. This will give you closed-box quality (or better) and ported extension in a small size. Drawback is needing a strong amp that can drive low ohm loads and the need to buy two large toroids and two large inductors for the circuit.
Simon
Areas you can improve on greatly are in cabinet quality and bass extension and dynamics, by going 3-way.
Although baffle step will kick in at about 400hz on paper, B&W haven't had a problem making a full-sounding 2-way there, so the woofer element in your design doesn't need to be more efficient than the upper sections . You could end up with bass that is too efficient, which is another good reason for going active on the bass. If you need more reasons, here you go - the power handling and max ouput level of the speakers will be much higher by going active between bass and mid, and distortion reduced. It also means you have no passive parts to ruin damping of the woofer(s) so they'll sound tight and clean - and no large inductors to buy, as you'd need in a good 3-way.
Push-pull isobaric is a fairly pointless technology, it potentially doubles woofer cost, adds complexity and does what? Slightly reduces distortion. The main benefit is allowing you to use drivers that were designed for a larger box than you can accommodate. This is a moot point if you buy the correct woofer in the first place. Please at least consider this before buying the woofers.
Also, if you decide to go passive, consider quite a small closed box, enhanced by Graham Maynard's T-bass circuit. This will give you closed-box quality (or better) and ported extension in a small size. Drawback is needing a strong amp that can drive low ohm loads and the need to buy two large toroids and two large inductors for the circuit.
Simon
Any chance you have a quick sketch of your push/pull bass cabinet, so we can get an idea of what you intend to do?
Now, the design goal might be to use 'Push/Pull'. I think sometimes we all start out with a design concept we want to build around, then work from there. In a sense, it is an experiment to see just how well this particular design principle works. If so, then I guess we have to accept that as a principle of the overall design.
However, it would probably simplify your life if you went with something a little more straight forward. But then, again, maybe you don't want a simplified life. That's entirely up to you.
I'd still be interested in a sketch of the push/pull section so I have a better idea of what you are envisioning.
I think, as shown in the Watt Puppy Clone linked to by Sreten, keep the mibass/high section separate from the Low-Bass section. In fact, leave the B&W exactly as they are, and simply set them on top of the new, low-bass section you are building. I think that will assure you of the best possible outcome. That allows you to concentrate your efforts on the most variable aspect of the design; the push/pull section.
If this works out for you, then as a later project, you can consider integrating them into one unit.
Steve/bluewizard
Now, the design goal might be to use 'Push/Pull'. I think sometimes we all start out with a design concept we want to build around, then work from there. In a sense, it is an experiment to see just how well this particular design principle works. If so, then I guess we have to accept that as a principle of the overall design.
However, it would probably simplify your life if you went with something a little more straight forward. But then, again, maybe you don't want a simplified life. That's entirely up to you.
I'd still be interested in a sketch of the push/pull section so I have a better idea of what you are envisioning.
I think, as shown in the Watt Puppy Clone linked to by Sreten, keep the mibass/high section separate from the Low-Bass section. In fact, leave the B&W exactly as they are, and simply set them on top of the new, low-bass section you are building. I think that will assure you of the best possible outcome. That allows you to concentrate your efforts on the most variable aspect of the design; the push/pull section.
If this works out for you, then as a later project, you can consider integrating them into one unit.
Steve/bluewizard
Interesting project, I have the DM602 S3's myself which I've used with and without subwoofers
I think the article is erroneous in saying it's a fourth order crossover. The spec states "2 way, Fourth order vented box" whereby the fourth order presumably refers to the bass rolloff of this type of alignment? I believe the crossover is in fact 1st order, 6db/octact, as is the case with most B&W designs, including the newest version of this model (685)
I think the article is erroneous in saying it's a fourth order crossover. The spec states "2 way, Fourth order vented box" whereby the fourth order presumably refers to the bass rolloff of this type of alignment? I believe the crossover is in fact 1st order, 6db/octact, as is the case with most B&W designs, including the newest version of this model (685)
Hi,
I'm pretty sure the 600 series 2nd generation were all 2nd order electrical slopes. Obviously combined high and low-pass could mean 4th order.
A friend had some 603 s1 and still has 603 s2 - they're fun party speakers because of the ~45hz tuning (at a guess) and twin 7" woofers (one kevlar midwoofer, 2nd "0.5" paper/kevlar woofer). They do make everything sound quite coloured but it's a nice colour.
Boxes are not very thick veneered chipboard, designed to resonate in the bass region I think. The 603 s1 used a passive radiator AND port together for porridge-like bass. Ideal for low quality sources and pop or dance music. The magnets on their drivers are not very large, quite puny in fact.
Nothing good by itself, but a euphonic combination of parts, which is why I advise against killing a great crossover.
Simon
I'm pretty sure the 600 series 2nd generation were all 2nd order electrical slopes. Obviously combined high and low-pass could mean 4th order.
A friend had some 603 s1 and still has 603 s2 - they're fun party speakers because of the ~45hz tuning (at a guess) and twin 7" woofers (one kevlar midwoofer, 2nd "0.5" paper/kevlar woofer). They do make everything sound quite coloured but it's a nice colour.
Boxes are not very thick veneered chipboard, designed to resonate in the bass region I think. The 603 s1 used a passive radiator AND port together for porridge-like bass. Ideal for low quality sources and pop or dance music. The magnets on their drivers are not very large, quite puny in fact.
Nothing good by itself, but a euphonic combination of parts, which is why I advise against killing a great crossover.
Simon
I really don't recommend you to use both 10" down to 40Hz and then use your 15" down to ~16Hz.
1. If you are going to use passive crossover the coils will be costly.
2. You'll probably get severe groupdelay issues.
Why don't you just let either the 10:s play all the way down to 16hz or build another 15" and let them play 80-16Hz?
If you want headroom and lower distortion with 10" use near wall/floor placement to raise sensitivity instead of a isobaric solution.
It works really well!
My system is similar to yours, the same size of elements.
Satellites: 87db @ 2.83v @1m, Fb=40Hz
Basmodules: +100dB @ 2.83Vrms @ 1m, Fb=26Hz
Finally:
If you decide to make a new box, keep the distance between the B&W speakers and the crossover.
1. If you are going to use passive crossover the coils will be costly.
2. You'll probably get severe groupdelay issues.
Why don't you just let either the 10:s play all the way down to 16hz or build another 15" and let them play 80-16Hz?
If you want headroom and lower distortion with 10" use near wall/floor placement to raise sensitivity instead of a isobaric solution.
It works really well!
My system is similar to yours, the same size of elements.
Satellites: 87db @ 2.83v @1m, Fb=40Hz
Basmodules: +100dB @ 2.83Vrms @ 1m, Fb=26Hz
An externally hosted image should be here but it was not working when we last tested it.
Finally:
If you decide to make a new box, keep the distance between the B&W speakers and the crossover.
Big cheers on all replies and links on different design options!
I have bad habit of presuming people already know what I'm taking about so do I apologize!
I've provided link of member that has done very similar design to what proposing to do except his pulling driver is on front baffle which mine will be located on rear baffle directly behind front driver.
Not very good at cad but will get some sort of picture up soon to show where I want to go with this design.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=128236&highlight=
The bass box design is not isobaric compound push/pull,don't like isobaric compound designs so should have been clearer on detail here,but even order canceling type push/pull arrangement.
Another point,speakers will be completely decoupled with bass section in separate enclosure,detached mid range and tweeter in separate enclosure sitting above bass unit.
The mid range driver is same used by B&W in their full 3-way 604 s2 crossover @ 450hz and 605 s2 crossover @ 230hz complete 1st order both sealed enclosures of 11-13litres,so will try those sizes for mid range.
Crossover will be in separate enclosures close to amplifier.
Simon,I hear what your saying,don't molester original crossover!
I did do little mod as listening test couple years back to one box reversing phase on tweeter adding 2nd order 12db @3.2khz and was shocked at how great it sounded,so am confident crossover can be redesigned with proper measurements first,but if not will take your advice just upgrade original with better parts.
I had links but lost them when my computer raid/hdd crashed last year,with details of recommended mods to 602 s2 with suggested crossover best at between 2.8khz -3.2khz.
B&W claim 4khz but is actually 3.5khz.
With cabinets,I'll be making 10mm pine frame fully braced gluing 20mm granite panels and bitumen damping applied to internal walls.Steering away from mdf which I used to use.
I haven't decided absolutely on full design so may end up different as yet,though really want to try push pull design which has plagued my mind for years now.
Used these speakers for over 7 years as sub/sat with 15" Jamo 3015 servo thx subwoofer so wanted to increase sound quality by going 3-way sub setup.
Thanks,
Steven.
I have bad habit of presuming people already know what I'm taking about so do I apologize!
I've provided link of member that has done very similar design to what proposing to do except his pulling driver is on front baffle which mine will be located on rear baffle directly behind front driver.
Not very good at cad but will get some sort of picture up soon to show where I want to go with this design.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=128236&highlight=
The bass box design is not isobaric compound push/pull,don't like isobaric compound designs so should have been clearer on detail here,but even order canceling type push/pull arrangement.
Another point,speakers will be completely decoupled with bass section in separate enclosure,detached mid range and tweeter in separate enclosure sitting above bass unit.
The mid range driver is same used by B&W in their full 3-way 604 s2 crossover @ 450hz and 605 s2 crossover @ 230hz complete 1st order both sealed enclosures of 11-13litres,so will try those sizes for mid range.
Crossover will be in separate enclosures close to amplifier.
Simon,I hear what your saying,don't molester original crossover!
I did do little mod as listening test couple years back to one box reversing phase on tweeter adding 2nd order 12db @3.2khz and was shocked at how great it sounded,so am confident crossover can be redesigned with proper measurements first,but if not will take your advice just upgrade original with better parts.
I had links but lost them when my computer raid/hdd crashed last year,with details of recommended mods to 602 s2 with suggested crossover best at between 2.8khz -3.2khz.
B&W claim 4khz but is actually 3.5khz.
With cabinets,I'll be making 10mm pine frame fully braced gluing 20mm granite panels and bitumen damping applied to internal walls.Steering away from mdf which I used to use.
I haven't decided absolutely on full design so may end up different as yet,though really want to try push pull design which has plagued my mind for years now.
Used these speakers for over 7 years as sub/sat with 15" Jamo 3015 servo thx subwoofer so wanted to increase sound quality by going 3-way sub setup.
Thanks,
Steven.
Well Steve, now I see more details I'm impressed. It sounds like you have some well-defined ideas about what you want, and the design sounds good.
Do you like the treble? I find even the £2500 B&W speakers to have a tizzy sounding treble, in absolute quality terms. I think it's nicely detailed and airy though. Perhaps I'm just a sucker for (almost any) soft domes.
Simon
Do you like the treble? I find even the £2500 B&W speakers to have a tizzy sounding treble, in absolute quality terms. I think it's nicely detailed and airy though. Perhaps I'm just a sucker for (almost any) soft domes.
Simon
Just one man's opinion, but I would build this in a staged approach.
To start, leave the B&W as they are, and concentrate on the bass cabinets. Even if you eventually change the mid-bass to high crossover, once you get it right, the low-bass to mid-bass crossover is not likely to change.
I suggest building a quick and dirty MDF mock up of your bass cabinet. You might even want to built it oversized so you can use a shelf to tune the internal volume a bit.
Then when you are satisfied with the bass design, you can built the final fancy version.
Now, that you have the bass sorted out, you can start on the mid-bass/high cabinet and crossovers.
I think if you try and do it all at once, you are going to introduce too many variables, and are going to have a hard time determining what is causing what characteristic in the final sound.
I know that add to the cost, but it will probably produce the best results in the end.
If you can't build it twice, once in a mock up and once in the final version, then don't do the detailed finishing on your final cabinet until you are sure it is right. I suspect once the stone side panels go on, the cost of modifications goes up significantly.
You seen to have design and modeling software; is it safe to assume you have testing software as well, so you can actually take measurements on the speakers?
Again, just a suggestion.
Steve/bluewizard
To start, leave the B&W as they are, and concentrate on the bass cabinets. Even if you eventually change the mid-bass to high crossover, once you get it right, the low-bass to mid-bass crossover is not likely to change.
I suggest building a quick and dirty MDF mock up of your bass cabinet. You might even want to built it oversized so you can use a shelf to tune the internal volume a bit.
Then when you are satisfied with the bass design, you can built the final fancy version.
Now, that you have the bass sorted out, you can start on the mid-bass/high cabinet and crossovers.
I think if you try and do it all at once, you are going to introduce too many variables, and are going to have a hard time determining what is causing what characteristic in the final sound.
I know that add to the cost, but it will probably produce the best results in the end.
If you can't build it twice, once in a mock up and once in the final version, then don't do the detailed finishing on your final cabinet until you are sure it is right. I suspect once the stone side panels go on, the cost of modifications goes up significantly.
You seen to have design and modeling software; is it safe to assume you have testing software as well, so you can actually take measurements on the speakers?
Again, just a suggestion.
Steve/bluewizard
Hi,
Sorry been very busy haven't had time to reply.
I've added rough picture of proposed design.
Will be doing this in staged approach with dummy cabinets but have to see what mid section is telling first through measurements,I think.
With 602 cabinet will seal off and test different volumes,saves making extra dummy boxes.
Aiming to flatten response in mid range getting rid of 6khz dip hopefully through different crossover points and cabinet redesign without notch filters if possible.
I do have an assortment of measure & design pc based software,spl meter,multi meters,mics ect...
Simon,I do find your comments right regarding tweeter!
Tweeter is a little bit harsh at times attention drawing,also dependent on electronics,but currently don't have plans to replace it just yet.
Also,I never could listen to these speakers directly,only by placing them 0.8meters approx above listening position sounded holographic and best to me.
Weird I know!
May replace with ribbons later but 7" mid woofer is main reason behind keeping combo instead of complete new build.
Will be testing tweeter removing rear plastic tapper tube converting to open transmission drive in different enclosures,free space,types of damping materials.
I have spare tweeter cover which I might experiment with by spraying light coat of clear acrylic paint to see if can balance out sensitivity by adding slight mass if extreme needed.
I have had some experience with top end B&W 801N,802N,801M,802M's and find older ones just as good as newer models which relative has 801M/Krell combo that still sounds incredible.
Due to other commitments,won't be able to start building for 2-3weeks but will post B&W tweeter/mid woofer t/s parameter measurements for future reference for anyone with B&W 602 s2 once done.
Cheers,
Steven.
Sorry been very busy haven't had time to reply.
I've added rough picture of proposed design.
Will be doing this in staged approach with dummy cabinets but have to see what mid section is telling first through measurements,I think.
With 602 cabinet will seal off and test different volumes,saves making extra dummy boxes.
Aiming to flatten response in mid range getting rid of 6khz dip hopefully through different crossover points and cabinet redesign without notch filters if possible.
I do have an assortment of measure & design pc based software,spl meter,multi meters,mics ect...
Simon,I do find your comments right regarding tweeter!
Tweeter is a little bit harsh at times attention drawing,also dependent on electronics,but currently don't have plans to replace it just yet.
Also,I never could listen to these speakers directly,only by placing them 0.8meters approx above listening position sounded holographic and best to me.
Weird I know!
May replace with ribbons later but 7" mid woofer is main reason behind keeping combo instead of complete new build.
Will be testing tweeter removing rear plastic tapper tube converting to open transmission drive in different enclosures,free space,types of damping materials.
I have spare tweeter cover which I might experiment with by spraying light coat of clear acrylic paint to see if can balance out sensitivity by adding slight mass if extreme needed.
I have had some experience with top end B&W 801N,802N,801M,802M's and find older ones just as good as newer models which relative has 801M/Krell combo that still sounds incredible.
Due to other commitments,won't be able to start building for 2-3weeks but will post B&W tweeter/mid woofer t/s parameter measurements for future reference for anyone with B&W 602 s2 once done.
Cheers,
Steven.
Attachments
conversion of B&W to 3 way
Hello:
Your project sounds interesting, but sounds like an awful lot of work to go through to get a marginal improvement in sound quality. If you like your 602's, I'd go along with the person who suggested adding the bass section first, and seeing how you like that.
You mentioned also that some other models of that series, (603, 604?) you liked better. You could probably have someone here in the States ship them them to you without a lot of effort or expense, and keep your 602's original. (best resale value)
If you are going to go to all the work to build these new cabinets, which would result in a fabulous enclosure, and rework crossovers, why keep the part of the B&W which is the cheapest part to replace? (The drivers) B&W is a master at combining various matrial to get the very best performance out of them. Changing those parameters might not have the effect you desire.
One last thought...invest in good active crossovers. They will make this whole process easier, and more flexible.
Just my 2 cents worth.
Hello:
Your project sounds interesting, but sounds like an awful lot of work to go through to get a marginal improvement in sound quality. If you like your 602's, I'd go along with the person who suggested adding the bass section first, and seeing how you like that.
You mentioned also that some other models of that series, (603, 604?) you liked better. You could probably have someone here in the States ship them them to you without a lot of effort or expense, and keep your 602's original. (best resale value)
If you are going to go to all the work to build these new cabinets, which would result in a fabulous enclosure, and rework crossovers, why keep the part of the B&W which is the cheapest part to replace? (The drivers) B&W is a master at combining various matrial to get the very best performance out of them. Changing those parameters might not have the effect you desire.
One last thought...invest in good active crossovers. They will make this whole process easier, and more flexible.
Just my 2 cents worth.
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