So here's the story. Last weekend I went to the local dump where I always check the electronics area. I found a pair of B&W DM603 S3 speakers, and not knowing if they were working in any way I brought them home. A little cleanup and it turns out they seem to work fine (all 3 drivers in each speaker). I do this often (brought home a pair of Altec Model 14s a while back that work great, see image below) and I put them right into my main system, which has a DIY 6BM8 tube amp at about 1.8wpc.
My main speakers have been a pair of DIY "BOFU" boxes (designed by @Nelson Pass and which I built maybe 10 years ago, using the Pioneer BOFU "fullrange" driver) with a helper tweeter which is a JBL2402h crossed fairly high (around 5-6khz I think). Note below I'm playing with some Edgar horns with the BOFU boxes I had on loan from a friend - the JBLs weren't in the system at this time. I've liked those BOFU boxes - they reproduce well below 40hz quite nicely - and they have an ease or airy lightness and nimbleness.
Now, what I found was these B&W speakers have loads more detail and have better frequency response in comparison. But...they totally lack the light easy and airy sound of the BOFU/JBL. So I'm wondering if this is mostly a trade-off or can I have my cake and eat it too? Is this something a better tweeter or some other change could help with, or is it a bigger issue with the B&Ws? Do I really need to try out hundreds of speakers to find my muse? (don't answer that, I'm afraid I know the answer...).
Really, this has been an eye opening experience and I'm thinking about next steps in speaker land, so any thoughts would be welcome.
And did I mention my wife is a very tolerant woman? 😆
My main speakers have been a pair of DIY "BOFU" boxes (designed by @Nelson Pass and which I built maybe 10 years ago, using the Pioneer BOFU "fullrange" driver) with a helper tweeter which is a JBL2402h crossed fairly high (around 5-6khz I think). Note below I'm playing with some Edgar horns with the BOFU boxes I had on loan from a friend - the JBLs weren't in the system at this time. I've liked those BOFU boxes - they reproduce well below 40hz quite nicely - and they have an ease or airy lightness and nimbleness.
Now, what I found was these B&W speakers have loads more detail and have better frequency response in comparison. But...they totally lack the light easy and airy sound of the BOFU/JBL. So I'm wondering if this is mostly a trade-off or can I have my cake and eat it too? Is this something a better tweeter or some other change could help with, or is it a bigger issue with the B&Ws? Do I really need to try out hundreds of speakers to find my muse? (don't answer that, I'm afraid I know the answer...).
Really, this has been an eye opening experience and I'm thinking about next steps in speaker land, so any thoughts would be welcome.
And did I mention my wife is a very tolerant woman? 😆
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I know the feeling 😉
It would help to keep an open mind about whether the wanted effect is an accurate one or is an embellishment. I'd first compare the response, it may be simple to explain. If not then I'd move on to polars and compare the dispersion.
It would help to keep an open mind about whether the wanted effect is an accurate one or is an embellishment. I'd first compare the response, it may be simple to explain. If not then I'd move on to polars and compare the dispersion.
Another thing that might be at play is the speaker load, sensitivity, and the amount of power you have available. Without knowing how your amp behaves at various impedances and how the loads compare, it's hard to say what's what, but 1.8 watts is not many watts for a speaker of typical sensitivity. And the B&W isn't the easiest load in the range where you seem to have concerns.
https://www.stereophile.com/content/bw-dm603-s3-loudspeaker-measurements
"The speaker's impedance plot (fig.1), however, indicates that it is a moderately difficult load, at least at very high frequencies, where the magnitude drops to 3.1 ohms at 15kHz."
https://www.stereophile.com/content/bw-dm603-s3-loudspeaker-measurements
"The speaker's impedance plot (fig.1), however, indicates that it is a moderately difficult load, at least at very high frequencies, where the magnitude drops to 3.1 ohms at 15kHz."
Thanks both. I understand it could be embellishment that I'm hearing (in one or the other speakers or, perhaps, our hardwood floors, plaster walls and tin ceilings!!! Or even absence instead of embellishment - who's to know if I can't measure?). I hope to graduate to being able to measure in-room response at some point. I did notice that the 603s dip down to 3 ohms or so, but I'm wondering what that means in terms of audible sound. Would that make the 15k louder or affect the amp's ability to drive them or??? When spring arrives I can try a bunch of different amps, though I don't know what among my amps would handle the impedance curve well especially that spike at 2khz against the drop to 15k. All of this is kinda new to me. Again, I've never been able to measure in-room and I don't know much about speaker parameters and what they sound like. So any pointers to articles or other sources that might help me understand would be appreciated. My learning curve is very slow as I have a lot of non-audio stuff on my plate.
The B&W are way harder to drive imo, and can get you all the hifi sound.
I heard a lot the B&W in store many hours and I preferred the 805D it was the one giving me that WOW. They are very in your face, my current loudspeakers are laid back, I consider superior.
What you will not be able to get rid of is the sound signature and general balance of the B&W. I would suggest to try it with a high end ROTEL amp.
The amp is mostly the culprit because you can hear the background and air with other loudspeakers, so it is not the source components but the drive.
Speakers with more resolution have a lot of control and low sensitivity and need a ton of instant juice (AMPS) and no phase shift and a clean feedback path.
What I have found is that some cheap old 3 ways have way more distortion and punch than my 'accurate' setup.
The triode low power 6bl7 amp in parallel drive them with ease and they sound dynamic but lack the air and accuracy of my hifi setup. But the children love the sound and cant care less for accuracy.
The tube amp sounds lethargic at normal volumes on hifi speakers, only in a bedroom or nearfield they sound superb.
I heard a lot the B&W in store many hours and I preferred the 805D it was the one giving me that WOW. They are very in your face, my current loudspeakers are laid back, I consider superior.
What you will not be able to get rid of is the sound signature and general balance of the B&W. I would suggest to try it with a high end ROTEL amp.
The amp is mostly the culprit because you can hear the background and air with other loudspeakers, so it is not the source components but the drive.
Speakers with more resolution have a lot of control and low sensitivity and need a ton of instant juice (AMPS) and no phase shift and a clean feedback path.
What I have found is that some cheap old 3 ways have way more distortion and punch than my 'accurate' setup.
The triode low power 6bl7 amp in parallel drive them with ease and they sound dynamic but lack the air and accuracy of my hifi setup. But the children love the sound and cant care less for accuracy.
The tube amp sounds lethargic at normal volumes on hifi speakers, only in a bedroom or nearfield they sound superb.
With reference to your title resolution vs air I always considered them as separate things. You have both one or none.
Rob 🙂
Rob 🙂
It shouldn't mean anything but some amps might handle it differently.
Even RTA/noise measurement from a couple of feet back should give you something to work with. Data like that can get you off the ground.
If your amp has high output impedance, that will also limit power into low impedance loads (a greater percentage of output is dropped across the output impedance of the amp as the load impedance decreases). Output impedance can vary greatly - some tube amps have lower values, while others can be quite high.
Some random low-watt tube results from Stereophile, though they are obviously different tubes than yours, so your mileage may vary:
https://www.stereophile.com/content/air-tight-atm-211-tube-monoblock-power-amplifier-measurements
"the Air Tight amplifier is specified at 22W into 8 ohms (13.4dBW)—quite a high power for a single-ended design. Yet plotting its 1kHz output power vs THD+noise into resistive loads (fig.7) reveals that the usual 1% THD clipping point has to be relaxed to 3% for the amplifier to meet its specified power into 8 ohms. This graph confirms that the amplifier is most linear into 16 ohms, but the fact that slightly more power is available into 8 ohms confirms that this is the load best matched to the output transformer. Only a few watts are available into 4 and 2 ohms, however."
https://www.stereophile.com/content/borderpatrol-p21-exd-power-amplifier-measurements
"BorderPatrol specifies the P21 EXD as delivering up to 20Wpc (13dBW), presumably with the load matched to the nominal output transformer tap. With clipping defined as when the THD+noise in the output reaches 1%, I measured a clipping power of 19.5Wpc into 8 ohms from the 8 ohm tap (12.9dBW, fig.6) and into 4 ohms from the 4 ohm tap (9.9dBW, fig.7), with both channels driven. With the 8 ohm tap driving 4 ohms (fig.8), the BorderPatrol clipped at 7.1Wpc (5.5dBW). It did better when the load impedance was higher than the tap value, the 4 ohm tap clipping at 15Wpc into 8 ohms (11.8dBW, fig.9)."
https://www.stereophile.com/content...e-lx20-monoblock-power-amplifier-measurements
"the 300SE LX20 gave a load-matched average of 18.5W midband (4 ohm tap to 4 ohm load, 8 ohm tap to 8 ohms), though 4 ohm loading on the 8 ohm tap severely lowered the output to 5W at 1kHz."
https://www.stereophile.com/content...monoblock-power-amplifier-measurements-part-2
"in figs.6 and 7, which show the small-signal THD+noise percentage from the amplifier's 8 ohm tap plotted against frequency into resistive loads ranging from 16 down to 2 ohms and into our simulated speaker. The distortion rises significantly into all loads in the bass, which suggests RD was wise to use a powered subwoofer. But it also rises into loads both higher and lower than the nominal transformer tap value"
Some random low-watt tube results from Stereophile, though they are obviously different tubes than yours, so your mileage may vary:
https://www.stereophile.com/content/air-tight-atm-211-tube-monoblock-power-amplifier-measurements
"the Air Tight amplifier is specified at 22W into 8 ohms (13.4dBW)—quite a high power for a single-ended design. Yet plotting its 1kHz output power vs THD+noise into resistive loads (fig.7) reveals that the usual 1% THD clipping point has to be relaxed to 3% for the amplifier to meet its specified power into 8 ohms. This graph confirms that the amplifier is most linear into 16 ohms, but the fact that slightly more power is available into 8 ohms confirms that this is the load best matched to the output transformer. Only a few watts are available into 4 and 2 ohms, however."
https://www.stereophile.com/content/borderpatrol-p21-exd-power-amplifier-measurements
"BorderPatrol specifies the P21 EXD as delivering up to 20Wpc (13dBW), presumably with the load matched to the nominal output transformer tap. With clipping defined as when the THD+noise in the output reaches 1%, I measured a clipping power of 19.5Wpc into 8 ohms from the 8 ohm tap (12.9dBW, fig.6) and into 4 ohms from the 4 ohm tap (9.9dBW, fig.7), with both channels driven. With the 8 ohm tap driving 4 ohms (fig.8), the BorderPatrol clipped at 7.1Wpc (5.5dBW). It did better when the load impedance was higher than the tap value, the 4 ohm tap clipping at 15Wpc into 8 ohms (11.8dBW, fig.9)."
https://www.stereophile.com/content...e-lx20-monoblock-power-amplifier-measurements
"the 300SE LX20 gave a load-matched average of 18.5W midband (4 ohm tap to 4 ohm load, 8 ohm tap to 8 ohms), though 4 ohm loading on the 8 ohm tap severely lowered the output to 5W at 1kHz."
https://www.stereophile.com/content...monoblock-power-amplifier-measurements-part-2
"in figs.6 and 7, which show the small-signal THD+noise percentage from the amplifier's 8 ohm tap plotted against frequency into resistive loads ranging from 16 down to 2 ohms and into our simulated speaker. The distortion rises significantly into all loads in the bass, which suggests RD was wise to use a powered subwoofer. But it also rises into loads both higher and lower than the nominal transformer tap value"
B&W needs 200W McIntosh amp..( hard to find in recycling center ) to show the purpose it was built for. I never liked those speakers but it aint a Polk. 1.8W amp won't even compensate crossover loses. It's all in the clipping range. Never heard a Rotel amp I liked and their CD player neither but I keep hoping. There must be plenty of them in recycling center.
I used the BOFU as a substitute woofer in the Radio Shack Electrostatic 2a bookshelf and it worked fairly well. Where that driver falls down IMHO is voice clarity. The electrostatic tweeters cross at about 5k. I feel that a midrange of some type needs to introduced. I wanted to try an Alpair 12 as a woofer but never got around to it.
Thanks all. A lot to digest here. But let me say for now the 603s are supposedly 90dB, and I can attest to the fact that there is no shortage of SPLs at the listening position, maybe 9 feet/3 meters away and that's with the pot below the half point, so although I haven't scoped its output, I'm guessing that I'm below 1w and well below clipping most of the time). And those SPLs are pretty good. It's probably considered a pretty lively room, which may boost the SPLs (I DO one day hope to work on sound treatments). I find resolution to be surprisingly good throughout my audible range (I'm probably headed to 12k as my limit!). In short, these would be pretty fantastic if they had that sparkle and airy ease. Since I'm about the only listener, it's possible I just have the treble on my DIY boxes much higher to compensate for my aged hearing loss (the JBLs are currently on l-pads which I occasionally adjust), but that wouldn't seem to be related to that easy presentation of my DIY speakers.
I suspect dynamic range is at least part of the problem, as is that 15k dip (likely above my hearing level, but I suspect I'd know if there were trouble there). Now, as I said above, I'll definitely try some other amps, culminating in a Marsh A200 amp (which is the most powerful and current capable amp I have on hand). My real question has to do with how do I find my holy grail of speakers, or am I chasing an elusive ghost? I feel pretty sure I'll one day find it, and I'm also pretty sure it will be a combination of source, amp AND speakers. But understanding what is going on with a given setup would help me find what I love more quickly.
I should also note that my audio budget is nearly non-existent which is partly why I DIY a fair amount of gear and is also why I dumpster dive. If that's un-American, then I'm OK being un-American. (And my list of dump finds is pretty crazy - what people throw out!)
I suspect dynamic range is at least part of the problem, as is that 15k dip (likely above my hearing level, but I suspect I'd know if there were trouble there). Now, as I said above, I'll definitely try some other amps, culminating in a Marsh A200 amp (which is the most powerful and current capable amp I have on hand). My real question has to do with how do I find my holy grail of speakers, or am I chasing an elusive ghost? I feel pretty sure I'll one day find it, and I'm also pretty sure it will be a combination of source, amp AND speakers. But understanding what is going on with a given setup would help me find what I love more quickly.
I should also note that my audio budget is nearly non-existent which is partly why I DIY a fair amount of gear and is also why I dumpster dive. If that's un-American, then I'm OK being un-American. (And my list of dump finds is pretty crazy - what people throw out!)
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Audio is a very personal thing and the only person who has to be fairly happy with the sound of your system is you and nobody else. Indeed we live in the times when getting a sound which could be described as a " dream system " during my youth is fairly accessible for free as a curb pickup or almost free by second hand purchases which I also practice. I never bought a new audio product from the store. B&W recommends 30-200 W Amp of unclipped power capability for this speaker. They should know since they designed the speakers along those design objectives for optimal results.
the b&w small towers are awesome for the price, real intro to good speakers, but to get to the 'there' awesomeness, you need to get to the diamond line.
It is always a compromise.... Sensitivity and Amp power means almost nothing ....
Compared to the other beasts you have the B&W should give you more bells and whistles it is more sophisticated and balanced, less THD, but you need to abandon tubes imo...
I have been trying to use tube amps on modern speakers without disastrous results for 15 years, I finally found a SS amp which could destroy my tube amps.
It is always a compromise.... Sensitivity and Amp power means almost nothing ....
Compared to the other beasts you have the B&W should give you more bells and whistles it is more sophisticated and balanced, less THD, but you need to abandon tubes imo...
I have been trying to use tube amps on modern speakers without disastrous results for 15 years, I finally found a SS amp which could destroy my tube amps.
as for rotel not sound nice, I disagree, I don't like the cambridge audio clinical dry sound, but it is interesting. The rotel sound in their class AB amps is quite relaxed, detailed with a bright and ultra detailed sound, a lot of ambiance too, they are very emotional amplifiers I found!!! I heard the BW 802 804 and the 805 with rotel was the most coherent and very emotional to listen too.
My experience with B&W is the tweeters benefit from better caps. B&W uses Mundorf in the higher end pieces for a reason. Even the MKP caps (super affordable) can be worth it. I'm not a huge fan of Mundorf Supreme variations, I find them too saturated, but they sound much smoother IMHO than stock.
Eriksquires, I am now so far in my audio quest that capacitor doesn't matter anymore at all, everything is light years away from sound of resistors or capacitors 🙂, LOL, I am passing Pluto at the moment...
living a huge Horah dance presently until further notice
living a huge Horah dance presently until further notice
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