Trouble with Bowers and Wilkins 804 D3

[Verdinut]

As I can figure, the 804D3s are ported enclosures, but the 700 Series enclosure is most likely a sealed cabinet.

If this is exact, that might explain why you damage the woofers in your 804s.

IMO, you are simply driving them too hard below the tuning frequency of the cabinets. Below the tuning frequency, the woofer cones are no longer loaded by the air entrapped in the cabinet and the ducted port, they are driven beyond their Xmax.

 

[TLS Guy]

When I got this system in July I had the 804 d3 as my left and right with a 7 series center. Since then I have blown 8 woofers on the left and right and about 1 week ago I finally got the diamond series center to match the left and right speakers. The first movie I watched with the New center the speaker blew out. This happened within the first 20min of the movie. I was just wondering why I never had any issues with the 7 series center but the new diamond series center blew right away. Looking at audyssey they both had almost the same corrections applied to them but the cheap one stood the test of time and a lot more action packed lowder movies and the expensive one died out on the very first explosion at not even the normal level I listen to.

Audyssey is part of your problem. Audyssey is a dreadful program and in my view should never be used at least not the Eq part and dynamic Eq.

Take a look at my 3 part article on Audyssey.

 

[Turk]

Audyssey is part of your problem. Audyssey is a dreadful program and in my view should never be used at least not the Eq part and dynamic Eq.

Take a look at my 3 part article on Audyssey.

Do you think Dirac live would have the same issues?

 

[TLS Guy]

Do you think Dirac live would have the same issues?

I think it would, as this whole concept is flawed. The issue is that the first arrival needs to come from a really good speaker with impeccable response. If you try and correct room reflections, which for most rooms is not necessary and make the correction via the sound coming from the speaker then you have mucked up the direct sound from a very good speaker.

 

[PENG]

When I got this system in July I had the 804 d3 as my left and right with a 7 series center. Since then I have blown 8 woofers on the left and right and about 1 week ago I finally got the diamond series center to match the left and right speakers. The first movie I watched with the New center the speaker blew out. This happened within the first 20min of the movie. I was just wondering why I never had any issues with the 7 series center but the new diamond series center blew right away. Looking at audyssey they both had almost the same corrections applied to them but the cheap one stood the test of time and a lot more action packed lowder movies and the expensive one died out on the very first explosion at not even the normal level I listen to.

Thank you for clarifying this, my observations are as follow:

1. The HTM71 s2 likely have totally different characteristic and Audyssey might have set the level lower by a few dB when they were in place.
2. The boost are not the same if you look carefully, where it maxed out, the frequencies were closer to that of the HTM D3 but quite different than the L and R channels.
3. The impedance of the HTM71 s2 at the 400-500 Hz where the boost peaked in both cases could be very different. We don't have the graphs for either, but we do have the one for the L and R's 804 D3, and the impedance in that range is about 4 ohms.
4. The 804 D3's low frequency response is more extended, by almost a full octave. Again crossover is not a brick wall.

I agree it is hard to explain why the HTM71 s2 didn't blow, but at least the 3 points I listed above may explain part of it, just that we don't know for sure without the impedance graphs and the level settings for the HTM71 s2 because they are no longer there, you do have it for the HTM D3 as you can go to check results to find out.

It is easier to explain the failures of the 804 D3 because you pushed them to reference level or higher, that means during some explosion, car chase and gun fire scenes etc there could be some sustained (in relative sense) peaks of 105 dB, or higher. That alone wouldn't have been an issue, but only when you combine that with you sitting distance, room size, and the very low impedance of those speakers right where Audyssey applies the most boost.

 

[PENG]

I think it would, as this whole concept is flawed. The issue is that the first arrival needs to come from a really good speaker with impeccable response. If you try and correct room reflections, which for most rooms is not necessary and make the correction via the sound coming from the speaker then you have mucked up the direct sound from a very good speaker.

IMO, it is only flawed for people who don't know how they work and the potential negative resulting issues. It's like medicine, one has to use them wisely as they are always side effects. If used wisely it helps more than not. A good room is like a healthy person, no medication needed. A bad room (acoustically) is like a sick person, who may benefit from medication, despite the side effects.

 

[PENG]

As I can figure, the 804D3s are ported enclosures, but the 700 Series enclosure is most likely a sealed cabinet.

If this is exact, that might explain why you damage the woofers in your 804s.

IMO, you are simply driving them too hard below the tuning frequency of the cabinets. Below the tuning frequency, the woofer cones are no longer loaded by the air entrapped in the cabinet and the ducted port, they are driven beyond their Xmax.

They are vented too, I googled it. If you look at the REQ boost, it is hard to explain and I would expect the mid range driver to blow, not the bass drivers. It is hard to explain that one for sure.

 

[PENG]

Do you think Dirac live would have the same issues?

I agree with TLSGuy, just partially. The issue would obviously be to different degree.

 

[<eargiant]

I agree with TLSGuy, just partially. The issue would obviously be to different degree.

Hey PENG, what exactly was so "Dumb" about post #31 way back early in this thread before we had more info that you felt the need to rate it that way now??

How did it vary much from what TLS guy suggested a few posts later in #37 & #40? Or even what Patrick Butler said in post #74 regarding playback levels? Or for that matter what TLS guy is still telling the OP in other threads about trying to push speakers to reference levels in his space?

Help me understand what exactly was so "dumb" about that post as an early guess/suggestion.

 

[Verdinut]

They are vented too, I googled it. If you look at the REQ boost, it is hard to explain and I would expect the mid range driver to blow, not the bass drivers. It is hard to explain that one for sure.

For the mid-range transducers, as you know, it would also depend on the crossover frequency from woofer to mid-range driver. B & W don't specify filter frequencies on their site.

Since the woofers are 6½ inch drivers, they might crossover as high as 500-600Hz easily and most of the power would have been driven into them then, procuring protection to the mid-frequency speakers. We also have to take into account that, in the case of an explosion, I may be wrong but I would assume that most of the power is split between low frequencies and tweeter frequencies rather than mid-frequencies.

 

[PENG]

Hey PENG, what exactly was so "Dumb" about post #31 way back early in this thread before we had more info that you felt the need to rate it that way now??

How did it vary much from what TLS guy suggested a few posts later in #37 & #40? Or even what Patrick Butler said in post #74 regarding playback levels? Or for that matter what TLS guy is still telling the OP in other threads about trying to push speakers to reference levels in his space?

Help me understand what exactly was so "dumb" about that post as an early guess/suggestion.

I have never given any post such rating, not me, but let me double check now.

Edit: There was nothing I felt even remotely dumb about that post. Good thing I could still undo it, I have no idea how it happen. May be I meant to click reply, that is directly above the rating and then somehow did not follow up with the reply. Thanks for telling me and I apologize.

 

[<eargiant]

I have never given any post such rating, not me, but let me double check now.

Edit: Good thing I could still undo it, I have no idea how it happen. May be I meant to click reply, that is directly above it and then somehow did not follow. Thanks for telling me and I apologize.

No worries, thanks. I thought I missed something.

 

[PENG]

For the mid-range transducers, as you know, it would also depend on the crossover frequency from woofer to mid-range driver. B & W don't specify filter frequencies on their site.

Since the woofers are 6½ inch drivers, they might crossover as high as 500-600Hz easily and most of the power would have been driven into them then, procuring protection to the mid-frequency speakers. We also have to take into account that, in the case of an explosion, I may be wrong but I would assume that most of the power is split between low frequencies and tweeter frequencies rather than mid-frequencies.

Could be, by the way, the main reason why I zero in on the Audyssey EQ boost as a factor (after highfigh brought it up) is that typically people blew the diamond tweeter, but the OP blew the woofers, 8 times iirc, yet he never blew any tweeters, yet.

 

[Turk]

I’m just surprised about the b&w having issues because of the utter abuse I gave my old motion 40’s for almost 10 years in multiple different room setups and 3 different avr’s the last one which was a marantz with audyssey, and even my deftech 8060’s where I have run so loud and hard to the extent where my marantz shut itself down from over heating. With these new speakers I haven’t come close to those levels yet. But I guess Maybe audyssey might just be boosting the 804 speakers in the right area that is destroying the woofers almost instantly.

 

[TLS Guy]

I’m just surprised about the b&w having issues because of the utter abuse I gave my old motion 40’s for almost 10 years in multiple different room setups and 3 different avr’s the last one which was a marantz with audyssey, and even my deftech 8060’s where I have run so loud and hard to the extent where my marantz shut itself down from over heating. With these new speakers I haven’t come close to those levels yet. But I guess Maybe audyssey might just be boosting the 804 speakers in the right area that is destroying the woofers almost instantly.

The reasons are simple, Audyssey and wrong application. As stated every 3db boosts doubles the power to the drivers at the boost frequency.

The motion 40s had a sensitivity of 92 db 2.83 volts one meter. The spec for the 804 D3 is 89 db but third party measurements show that it is in fact around 86 db 2.83 volts 1 meter.

However that does not tell the whole story. The impedance if the 804s drops to 2.4 ohms and does not rise to 4 from after the bass tuning peaks to 500 Hz. So in fact the efficiency of the 804s is in fact much lower than the specs would lead you to believe. So in actuality the 804s are going to require about 10 times the power for the same spl or loudness.

The Deftechs were also more sensitive and have a built in sub.

Now the f3 of the Motions 40s is around 40 Hz. The f3 of the 804 D3s is about an octave lower at 24 Hz. Now the difference in required cone excursion in the 804s and Motion 40s is going to be huge. In other words the 804s have to have a much greater xmax. So when you tried to deliver the same spl. as before you tore the suspension right off the voice coil.

This all comes about because of physics. As you lower bass extension given the same size drivers the drivers capable of the greater extension will be far less efficient. There is an inverse relationship between bass extension and efficiency.

So that makes the speaker with the bass extension much more vulnerable to over powering damage for multiple reasons.

Not only that but the Motion 40s have metal cones, and the B & Ws woven fabric cones. The metal cones have better thermal transfer.

So there are multiple reasons why you are blowing the drivers.

If you want good high power speakers then you need drivers with good heat transfer, an excellent motor system and above all bigger. To do what you want and have the same sound quality as the 804 D3s then you need at least a couple of 10" drivers.

The bottom line is, if you want the B & W 800 series sound then you need the 800 D3s.

If you can't afford them, then you need a less sophisticated speaker like you had before.

 

[PENG]

T

The bottom line is, if you want the B & W 800 series sound then you need the 800 D3s.

If you can't afford them, then you need a less sophisticated speaker like you had before.

Don't you think the 802 or even the 803 D3 can do it? The 803 D3 (http://www.bowers-wilkins.com/Speakers/Home_Audio/800_Series_Diamond/803-D3.html), at a little more than half the price of the 800 d3, it is much more affordable.

A full review with bench tests results is available here

 

[TLS Guy]

Don't you think the 802 or even the 803 D3 can do it? The 803 D3 (http://www.bowers-wilkins.com/Speakers/Home_Audio/800_Series_Diamond/803-D3.html), at a little more than half the price of the 800 d3, it is much more affordable.

A full review with bench tests results is available here

I think he will have the same problem. Here we have two 7" woofers but now with an F3 of 19 Hz.
I would bet that this chap will destroy those as well unless he can exhibit common sense.

If he wants a speaker with a low F3 he needs a speaker with 10" drivers if he wants those sort of playback levels. That is true even if he crosses at 90 Hz, as the speakers have to be high xmax given the low f3. There is still a lot of excursion at 100 Hz and above. I think he will have the same issue.

One last thing, that bloke should start a savings account for his hearing aids now.

 

[shadyJ]

I think he will have the same problem. Here we have two 7" woofers but now with an F3 of 19 Hz.
I would bet that this chap will destroy those as well unless he can exhibit common sense.

If he wants a speaker with a low F3 he needs a speaker with 10" drivers if he wants those sort of playback levels. That is true even if he crosses at 90 Hz, as the speakers have to be high xmax given the low f3. There is still a lot of excursion at 100 Hz and above. I think he will have the same issue.

One last thing, that bloke should start a savings account for his hearing aids now.

I don't understand listening at those levels, at least in a normal sized room. Even a typical bookshelf speaker can get loud enough for my tastes. In an average room, a tower speaker like those B&Ws should be able to get blazing loud. Although it does sound like he is over-driving them from low frequencies, so they are bottoming out, not surprising if you give them a hefty low-end boost. I can't believe he hasn't thought to use subwoofers which would take most of the strain off of the excursion.

One more thing, anyone who listens to music so loudly that they regularly blow out their drivers is due for a lot greater shortfall in hearing that typical hearing aides can compensate for. If I were him, I would just start trying to learn ASL now.

 

[<eargiant]

The reasons are simple, Audyssey and wrong application. As stated every 3db boosts doubles the power to the drivers at the boost frequency.

The motion 40s had a sensitivity of 92 db 2.83 volts one meter. The spec for the 804 D3 is 89 db but third party measurements show that it is in fact around 86 db 2.83 volts 1 meter.

However that does not tell the whole story. The impedance if the 804s drops to 2.4 ohms and does not rise to 4 from after the bass tuning peaks to 500 Hz. So in fact the efficiency of the 804s is in fact much lower than the specs would lead you to believe. So in actuality the 804s are going to require about 10 times the power for the same spl or loudness.

The Deftechs were also more sensitive and have a built in sub.

Now the f3 of the Motions 40s is around 40 Hz. The f3 of the 804 D3s is about an octave lower at 24 Hz. Now the difference in required cone excursion in the 804s and Motion 40s is going to be huge. In other words the 804s have to have a much greater xmax. So when you tried to deliver the same spl. as before you tore the suspension right off the voice coil.

This all comes about because of physics. As you lower bass extension given the same size drivers the drivers capable of the greater extension will be far less efficient. There is an inverse relationship between bass extension and efficiency.

So that makes the speaker with the bass extension much more vulnerable to over powering damage for multiple reasons.

Not only that but the Motion 40s have metal cones, and the B & Ws woven fabric cones. The metal cones have better thermal transfer.

So there are multiple reasons why you are blowing the drivers.

If you want good high power speakers then you need drivers with good heat transfer, an excellent motor system and above all bigger. To do what you want and have the same sound quality as the 804 D3s then you need at least a couple of 10" drivers.

The bottom line is, if you want the B & W 800 series sound then you need the 800 D3s.

If you can't afford them, then you need a less sophisticated speaker like you had before.

Great post!

 

[Turk]

I don't understand listening at those levels, at least in a normal sized room. Even a typical bookshelf speaker can get loud enough for my tastes. In an average room, a tower speaker like those B&Ws should be able to get blazing loud. Although it does sound like he is over-driving them from low frequencies, so they are bottoming out, not surprising if you give them a hefty low-end boost. I can't believe he hasn't thought to use subwoofers which would take most of the strain off of the excursion.

One more thing, anyone who listens to music so loudly that they regularly blow out their drivers is due for a lot greater shortfall in hearing that typical hearing aides can compensate for. If I were him, I would just start trying to learn ASL now.

Unfortunately until I can build a dedicated room my current set up is in a 17’ x 50’ room with 9’ ceilings that is also open to another area on one side. Sitting about 15-16 feet away

Music is about -20 when playing

But I’m a sucker for good action movies so it does tend to stay around 0 when the action is going on. There’s something about when a gun is fired and feeling it like your in the room with it. Hence the dual svs subs

I would 100% agree when I hear them in a show room in an average listing environment 0 is crazy loud!