00:00hey everybody welcome back today we've
00:02got an interesting speaker to look at
00:04this is what is now considered a vintage
00:08BMW speaker and this model is the 802
00:13802 um S2 version so um second version
00:18of this thing and I've got it up on the
00:20lift table so you can take a look at the
00:22whole speaker and I'm going to lower
00:25this thing down to where you can see all
00:26of it obviously a floor standing
00:30and it uses some type of a I think those
00:33may be a paper cone driver uh as far as
00:36the wolfers they're tuned fairly low the
00:39box is will really well braced this is
00:41kind of in their Matrix series design
00:43where there's a lot of bracing going on
00:45in there um then they're using their
00:48bulletproof Kevlar which is part of
00:50their advertising campaign at the time
00:52it's bulletproof and the little Tweeter
00:55pod that sits up there on the top of it
00:57and I will say that this modu design was
01:01a little bit of ahead of its time back
01:03then they did some things really well
01:06and they produced a pretty good product
01:11to a point there's also some
01:14shortcomings on this thing and I
01:16remember going back to the B&W dealers
01:19way back in the day and listening to a
01:22lot of bnw products and I'll never
01:24forget going into a store there in
01:25Oklahoma City where they had some 801
01:28setup which is basically the same
01:29speaker speaker but it had a single 12
01:31or 15in woer underneath it and they had
01:34it on some K amps and they had some big
01:38monstrous by-wire cable on there and I
01:40remember them telling me that the cable
01:42was five grand for the cable and I
01:46remember thinking if only they knew what
01:48was on the inside of that speaker
01:50they're hooking these $5,000 cables onto
01:53the back of binding posts that had steel
01:57nuts on the back of them and cheesy just
02:00common electrical wire and super cheesy
02:03Parts on the inside man I've been into a
02:07lot of these BMWs and especially the
02:13models this is what was on the inside
02:16and on this one it's it's it's easy to
02:18get to this thing because you can remove
02:20the bottom panel and this whole thing is
02:23just right there mounted to the bottom
02:24like this so you can unscrew it and
02:26remove the whole thing and there's
02:27probably just enough space in there to
02:30go in and build a whole new network to
02:32install in that same area the old
02:35crossovers has about 54 Parts on it and
02:39it has common electrical wiring going to
02:42push on connectors here or or I I should
02:45say crimp down connectors that's got
02:47steel nuts on them as well all of the
02:50inductors are iron core except the one
02:52that was on the Tweeter most of the
02:54capacitors are all electrolytic
02:56capacitors all the resistors are all the
02:59cheap s cast resistors there's a little
03:02protection circuit with dodes and tiny
03:04little resistors that are going on the
03:06tweeters and the and the mids or
03:09something there it's just it's just
03:11garbage to be honest with you even the
03:13circuit board itself isn't a copper
03:15Trace circuit board this is just
03:16aluminum or 10 or something it just you
03:20look at it and you just you just cringe
03:23when you see this stuff now the overall
03:26design of it as far as getting this out
03:29of the way as as far as quality is
03:32fairly okay like it has a fairly
03:34balanced response across the board and
03:37unlike some of the BMW models which the
03:39the little tweeters rang like crazy at
03:42the top I didn't see that in this model
03:44so this would be one of the Lesser
03:46fatiguing models to listen to uh but it
03:49does have a little bit of brightness
03:51right around 1, 11100 HZ there is a peak
03:53let's take a look at it this is the on
03:56aais frequency response and overall
03:58linearity is pretty good and the Tweeter
04:01is voiced down a little bit so if it was
04:04put in an overly bright room it wouldn't
04:07completely take your head off but that
04:09little spot there around 1 to 1100 HZ uh
04:131K Herz to 1100 Herz is definitely going
04:17brightness um looking at it IND
04:20individually so we can look at the
04:22woofers independent of the mid tweeters
04:25we can see that it crossed at about 360
04:28Herz which is not not that bad I
04:30wouldn't want to run these things up
04:32very high you've got a a small warer
04:34that's capable of going down fairly low
04:36you should let it do what it's can do
04:38and that's pretty much what they did now
04:41here's some of the good parts about the
04:44design this modular design minimizes
04:46surface Reflections quite a bit and it
04:49will really help improve Imaging and
04:50Sound Stage layering because you don't
04:53have as much surface reflection so
04:55without all the surface reflection you
04:57don't get the sound as if it's coming
04:59from the baffle it becomes a little more
05:01transparent because you just don't have
05:03these Reflections coming forward with
05:05the on axis response so looking at the
05:08vertical off axis it looks really really
05:10good that means as you're moving up that
05:14the the close Center to Center spacing
05:16of the drivers really helps in that they
05:18stay in phase over a pretty good range
05:20so they did a good job there and the
05:22horizontal off axis looks great and on
05:24all of these models that we've measured
05:27that have these different pods on there
05:29and this no surface area around anything
05:32they've always had pretty good off-axis
05:33response everything drops off fairly
05:35evenly um looking at the spectral Decay
05:38it looks fairly clean there's a little
05:41bit of a humped up area there at um at
05:45that spot where there's a peak between
05:461, 1100 Herz that little spot there it's
05:49a little heavier there but it's not bad
05:52and down in the woofer response there
05:54there's a little bit of stored energy
05:57there but it's not bad at all so that
06:00that wouldn't be too intrusive it would
06:02make vocals a little heavy but overall
06:06uh not too bad and that Peak there at
06:08between 1, 1100z is going to bring a
06:10little brightness to the top of female
06:13vocals that may want
06:15to you know it's it's going to be a
06:18little added Zing there um looking at
06:22the impedance we can see that it was
06:24tuned fairly low down in the low 20s and
06:27the impedance dropped to 3. 9 ohms so
06:31it's definitely going to require an
06:33amplifier that is stable down into 4
06:37so my job to try and improve the sound
06:41of these things that's why they're sent
06:43into me and we know we're not going to
06:46replicate this thing and we're going to
06:47get this garbage out of the signal path
06:49so my first job in going about the
06:52evaluation is to look at the individual
06:54driver responses and see what kind of
06:57range that they function in and see if
06:59I'm going to have to going in and
07:00correct for a bunch of stuff and get a
07:02good idea of what I'm working with so
07:04I'll shoot the drivers independently
07:06I'll shoot the Tweeter the mid and then
07:08the woofers and look at the spectral
07:10Decay so I can know if I've got stored
07:12energy issues that I got to deal with
07:13and things like that so let's throw this
07:16up let's look at the tweeter's response
07:19and the spectral decay of the Tweeter
07:21right under it we can see that there's a
07:23little bit of a humped up area in the
07:24tweeter's response but that's something
07:26I can correct uh most importantly in the
07:29SP Cal Decay we don't see a whole lot of
07:31ringing going on there so that's good
07:33looking at the mid um the mid-range
07:36response is a little choppy and and and
07:39it definitely has a loss of output as
07:42you go down further and when you put
07:44something in a pod like this you're
07:45going to have a lot of what we call step
07:48loss that means that there's no added
07:51gain from the surface area because there
07:52is no surface area so at about a th000
07:55Hertz the output starts to wrap around
07:58and become omnidirectional and when it
08:00does that it loses output so that's why
08:02you see everything below that range is
08:04just falling off and then we got a
08:06couple little humps there um around a
08:10th000 to a little over 2,000 and then
08:13there's a little big peak at the top but
08:15looking at the spectral Decay with it we
08:17can see that the only place we have to
08:19concern ourselves with with stored
08:21energy was right there around 1,000
08:22Hertz that's right there where that Peak
08:25was before um and it looks like it's
08:28it's got a little little bit ring to it
08:31not just an amplitude Peak looking at
08:33the wofer response um yeah that looks
08:36kind of rough and I'm still taking these
08:38measurements on Tweeter axis so I'm up
08:41here on the Tweeter axis the two woofers
08:43are below and you can see a huge suckout
08:46at around 2K Herz that's the time
08:49arrival difference from one woler to the
08:51other up there at that um height so
08:55that's what's causing that huge hole if
08:57I were to drop down on woler axis it
08:59would wouldn't have that but when we're
09:00designing the crossover we're basing
09:02everything on the output at the Tweeter
09:05so that's what it looks like at that
09:08position at one meter and when we go
09:11down lower in frequency those
09:13wavelengths are much longer and they
09:14don't cancel each other they're they're
09:16barely out of phase from the other it's
09:18like a it's it's just a little bit of
09:20phase rotation because the wavelengths
09:22are much much longer than they are at
09:252kz 2kz are like 6 in long but way down
09:28here in the range where we're going to
09:30use this thing these things are you know
09:3310 12T long so the differential between
09:36the Ral of one to the other there no big
09:38issue at all so yeah the spectral Decay
09:41looks really rough there's a lot of
09:42ringing and stuff going on but it's well
09:44out of the range that we're going to be
09:46using it so um of all the things on this
09:49thing the the lower range on these
09:52wolfers looks really good
09:55so next it was see what I can do with it
09:58so I put a crossover together that
10:00functioned well with these drivers and
10:03crossover uh graph up there so we can
10:06take a look at it and you can see I
10:08pushed the crossover point between the
10:11mid-base driver and the wolfers down a
10:12little further they were at about 360
10:14and I pushed it down to around 240 or
10:17something like that which that little
10:19woler is perfectly capable of that was
10:22that's no issue for that driver at all
10:23notice I was able to get a nice balanced
10:26response and there was a few Notch
10:28filters in that mid-range driver
10:31mid-base driver's response there or in
10:33its circuit that that notched out some
10:36of that stuff and I was able to do away
10:39with any of that those humps and the
10:41ringing uh looking at just the on AIS
10:43response alone it looks fantastic it
10:47really does it's extremely accurate now
10:50with the crossover that I put on there
10:52and then looking at the vertical off
10:53axis we can see it's even better uh
10:55going up and down it maintains its
10:58response over over the whole room
11:00vertically and then on the horizontal
11:02off axis again drops off extremely well
11:06it's it's one of those speakers you can
11:08put into the room and no matter where
11:10you're sitting in the room you're going
11:11to get a very accurate representation of
11:13what you would get even if you were on
11:15the on axis so that was great uh
11:18spectral Decay now looks a lot cleaner
11:20if you look even down low where there
11:23was some heaviness that would have
11:24created heaviness in the vocal it's not
11:26there anymore it's going to be a lot
11:28cleaner and a lot smoother you're going
11:29to get a lot better detail and
11:31resolution that was covered up before
11:34because those drivers were still ringing
11:37and still carrying those notes well past
11:40the input signal not not the case
11:42anymore and then looking at the
11:44impedance curve we can see that it only
11:46drops to 4.9 ohms now so I was able to
11:49do some stuff with it to keep it a
11:51little bit higher in impedance so it's a
11:54little friendlier for a bunch of
11:56amplifiers that you might drive it with
11:58so overall I was able to balance out the
12:02response really really well and in every
12:05direction um the crossover quality is
12:07going to go up a lot and it's going to
12:09go from 54 parts to 15 parts so I was
12:14able to do a lot more with a lot less
12:16and we're going to do all Air core
12:18inductors on the mid-base driver and the
12:21Tweeter we're going to do a really large
12:23laminated ey cor a super Q coil on the
12:26lower wolfers and good quity Parts
12:29throughout no more sandcast resistors
12:31and all that no more of this junk that's
12:34in there and these oh my goodness these
12:36were the type of binding posts that you
12:40saw often with the bar wire just pushed
12:42into it and you screw it down to tighten
12:44it on it it would also take a spade uh
12:47and it would take a banana plug but
12:50we're going to do away with that and
12:51just put one set of tube connectors on
12:53there and get all that out of the signal
12:55path so no more of this stuff that's
12:57going to improve Clarity quite a bit
12:59good wiring um I'll reexamine what's
13:02going on inside and see if there's any
13:04even any way we can add no reses the way
13:06this thing has that structural bracing
13:08thing going through it it's going to be
13:09very difficult but when I pull this back
13:11apart I'll really look at it and see if
13:14there's ways we can get in there and
13:15kind of help damp this out a little bit
13:17better uh but we'll see so we're going
13:19to put a whole package together you can
13:21look for it on the website and for all
13:24of you guys that have these things this
13:26is going to be a very very significant
13:29ific Improvement in performance across
13:31the board I mean lots better Clarity
13:34down in that vocal region where all that
13:36heaviness was all that's going to be
13:38gone you're going to hear much better
13:40definition and Clarity and then all the
13:42way up there across the top end where
13:44all these parts were smearing the signal
13:47you're going to hear a lot better
13:48resolution and Clarity so this one was a
13:51nice fun little project it'll be a fun
13:53little project for you guys the
13:54crossover should still fit in the bottom
13:57of the box and you've going to have to
14:00do some rewiring on this stuff and
14:02feeding the wires down through the
14:04passage and it's a little bit of a pain
14:06in the rear end to get it through there
14:08but you can rewire this whole thing and
14:12yeah look for it on our website if
14:14you're interested if you've got any
14:15comments please drop them in the comment
14:17section below I really appreciate you
14:20guys watching and I know these upgrade
14:22videos are kind of a a highlight get you
14:25not only do you see what we're doing but
14:27you get to see what these original
14:29speakers were and how they measured and
14:31what was inside of them I know that's a
14:33lot of fun sometimes too so I really
14:35appreciate you guys watching and if you
14:36hadn't subscribe please do and we'll see
14:39you in the next video