Very good to everyone. I show some aesthetic improvements that I have made on a couple of B&O Beovox S45-2 boxes. They are as you will know highly acclaimed boxes from the year 1982.
I have updated their capacitors (I would have liked to do it with film capacitors); perform internal damping and I have changed the fabrics of the grids.
I have used Sonic Barrier 1/2 "Acoustic Sound Damping Foam with PSA 18" x 24 "and Parts Express Speaker Grill Cloth Black Yard 70" Wide.
The side wood veneer I have embellished with brown wax for leather shoes.
The result I show photos.
The sound was already spectacular. Now it is even better.
I have updated their capacitors (I would have liked to do it with film capacitors); perform internal damping and I have changed the fabrics of the grids.
I have used Sonic Barrier 1/2 "Acoustic Sound Damping Foam with PSA 18" x 24 "and Parts Express Speaker Grill Cloth Black Yard 70" Wide.
The side wood veneer I have embellished with brown wax for leather shoes.
The result I show photos.
The sound was already spectacular. Now it is even better.
Attachments
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I think we all liked B&O speakers back in the 1970-80 era. They just looked terrific and sounded great. Black grilles, teak or rosewood cabinets and pretty aluminium trim. The ampifiers and turntables won design prizes too.
I owned a miniscule pair of Beovox 2702:
5" paper bass, 2" SEAS H087 tweeter (also used in the Dynaco A25). Some nice touches like wall mounting holes on the back:
Crossovers were generally minimal. The smaller still Beovox 1702 with 4" bass was like this, though I'd now guess the bass was 4 ohms. The H087 I could look up, and I did, it's 6 ohms:
B&O generally used Celestion and SEAS drivers with what is called high Qms or low-loss. Also 4 ohm units I think. DIN connectors were fashionable then, but dubious on tight connection by modern 4mm banana plug standards. Surprisingly scruffy crossover, but functional I suppose.
With respect ALPUY, you could tell us more here. I'd like to see the schematic. Also confirm the mid is in a little plastic enclosure. Measurements of speaker DCR would be of interest too, along with more detail about the driver models. You would then have made a good reference for people with this model, or interested in the design ideas.
It is often hard to get detail, but a classic speaker for sure.
I owned a miniscule pair of Beovox 2702:
5" paper bass, 2" SEAS H087 tweeter (also used in the Dynaco A25). Some nice touches like wall mounting holes on the back:
Crossovers were generally minimal. The smaller still Beovox 1702 with 4" bass was like this, though I'd now guess the bass was 4 ohms. The H087 I could look up, and I did, it's 6 ohms:
B&O generally used Celestion and SEAS drivers with what is called high Qms or low-loss. Also 4 ohm units I think. DIN connectors were fashionable then, but dubious on tight connection by modern 4mm banana plug standards. Surprisingly scruffy crossover, but functional I suppose.
With respect ALPUY, you could tell us more here. I'd like to see the schematic. Also confirm the mid is in a little plastic enclosure. Measurements of speaker DCR would be of interest too, along with more detail about the driver models. You would then have made a good reference for people with this model, or interested in the design ideas.
It is often hard to get detail, but a classic speaker for sure.
Information on Beovox S45-2 speakers is available here: Beovox S45-2 Passive Loudspeakers
I once renovated the 3cm less deep two-way Beovox S35 speakers and was surprised to find the legend 'Made in Japan' on the mid/bass drivers whose foam surrounds had disintegrated.
I once renovated the 3cm less deep two-way Beovox S35 speakers and was surprised to find the legend 'Made in Japan' on the mid/bass drivers whose foam surrounds had disintegrated.
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Good morning System 7. I have little to say about these wonderful speakers.
But I will tell you that the woofers are 8 "Peerlees; the mid (actually B&O does not call it medium but phase link) are 4" Seas 10FM, both 4 ohms; and the tweeter is Philips AD 162 T8 1 "and 8 ohms.
The crossover crosses at 3000 Hz 12dB octave, but the phase link is at that frequency at 6 dB octave.
It's a weird thing, because it would be a two-way with a speaker that phase compensates the mid frequencies.
The front of the boxes is designed in an inclined way, making the centers of the three speakers lie on the same plane. It will be so that they are in phase.
The characteristics are:
Continuous load: 45 watts
Music load: 65 watts
Impedance: 8 ohms
Frequency range + 4-8 dB: 48 - 20000Hz
Power at 96 dB SPL: 4 watts
Sensitivity 1W: 90 dB
Cabinet: Pressure chamber
Gross volume: 29,5 liter
Woofer: 20cm
Tweeter: 2.5cm
Crossover frequency: 3000 Hz
Dimensions WxHxD: 26.5 x 52.5 x 20cm
Weight: 6.5kg
It says that the boxes are 29.5 liters, but according to the internal measurements (45 x 15 x 23.5 cm), we would have 15.8 liters.
I do not know inductor values.
Greetings.
But I will tell you that the woofers are 8 "Peerlees; the mid (actually B&O does not call it medium but phase link) are 4" Seas 10FM, both 4 ohms; and the tweeter is Philips AD 162 T8 1 "and 8 ohms.
The crossover crosses at 3000 Hz 12dB octave, but the phase link is at that frequency at 6 dB octave.
It's a weird thing, because it would be a two-way with a speaker that phase compensates the mid frequencies.
The front of the boxes is designed in an inclined way, making the centers of the three speakers lie on the same plane. It will be so that they are in phase.
The characteristics are:
Continuous load: 45 watts
Music load: 65 watts
Impedance: 8 ohms
Frequency range + 4-8 dB: 48 - 20000Hz
Power at 96 dB SPL: 4 watts
Sensitivity 1W: 90 dB
Cabinet: Pressure chamber
Gross volume: 29,5 liter
Woofer: 20cm
Tweeter: 2.5cm
Crossover frequency: 3000 Hz
Dimensions WxHxD: 26.5 x 52.5 x 20cm
Weight: 6.5kg
It says that the boxes are 29.5 liters, but according to the internal measurements (45 x 15 x 23.5 cm), we would have 15.8 liters.
I do not know inductor values.
Greetings.
Attachments
Schematic is interesting. Don't really care who makes the drivers.
Trust me, ALPUY.
Most specifications don't tell me what I want to know. 🙂
WHY? Because Commercial Companies, like Defense Companies, guard their secrets. Most specs are a smokescreen for the really important details. 🙄
B&O developed something called the "Filler Driver". Idea was to eliminate time-delay.
You can build an 8" plus 1" two way.
B&O's strange idea was to wire the bass and tweeter out of phase. Normally would sound a bit weird and phasey. A big suckout at crossover. Often considered a test of phase alignment.
But due to a bit of algebra, it turns out you can add a lower order mid and fill the hole. Obviously worked to some extent, if only on-axis.
A subject of deep interest to some people here. But I assure you even amateurs can discover interesting things with effort. TBH, I get frustrated at the secrecy in our industry. Holds back progress.
Trust me, ALPUY.
Most specifications don't tell me what I want to know. 🙂
WHY? Because Commercial Companies, like Defense Companies, guard their secrets. Most specs are a smokescreen for the really important details. 🙄
B&O developed something called the "Filler Driver". Idea was to eliminate time-delay.
You can build an 8" plus 1" two way.
B&O's strange idea was to wire the bass and tweeter out of phase. Normally would sound a bit weird and phasey. A big suckout at crossover. Often considered a test of phase alignment.
But due to a bit of algebra, it turns out you can add a lower order mid and fill the hole. Obviously worked to some extent, if only on-axis.
A subject of deep interest to some people here. But I assure you even amateurs can discover interesting things with effort. TBH, I get frustrated at the secrecy in our industry. Holds back progress.
I'd better point out that the Peerless woofer in the S45-2 has a rubber surround so is not the same as the 'Japanese' woofer in the S35 which had a foam surround.
I note that the Beoworld specifications differ from yours, ALPUY.
I note that the Beoworld specifications differ from yours, ALPUY.
I read that the S45-2 had a 'Baekgaard' crossover named after Erik Baekgaard who worked for Bang & Olufsen in the 1970s - discussion here:
WMTMW Baekgaard
The 'filler' driver is said to be filtered with slopes of 6dB/octave on either side of the crossover frequency.
WMTMW Baekgaard
The 'filler' driver is said to be filtered with slopes of 6dB/octave on either side of the crossover frequency.
In the B&O crossover, the 'filler' driver is a necessity because, at the crossover frequency, the woofer and the tweeter have the same amplitude but relative 180 degree phase shift so cancel themselves out. If the 'filler' unit was not there, there would be a huge amplitude dip at the crossover frequency.
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Galu, you are right. send specifications of beovox s 45.
These are those of s 45-2
Beovox S45-2 Passive Loudspeakers Product Specifications
Type: 6312 (to Nov 1982)
Continuous load: 56 W
Music load: 75 W
Impedance: 4 - 8 ohms
Frequency response +4 -8 dB 38 - 20,000 Hz
Sensitivity: 5W
Gross volume |: 25 liters
Woofer: 20cm
Phase link unit 8cm
Tweeter: 2.5cm
Dimensions W x H x D: 26 x 48 x 21cm
Weight 7 kg.
In this link WMTMW Baekgaard
I read that the 45th sounds terrible.
I disagree. I compare it with my B&W DM602 and find it very nice to beovox.
I do not know if they are better or worse in terms of characteristics, but to the ear they are very good
These are those of s 45-2
Beovox S45-2 Passive Loudspeakers Product Specifications
Type: 6312 (to Nov 1982)
Continuous load: 56 W
Music load: 75 W
Impedance: 4 - 8 ohms
Frequency response +4 -8 dB 38 - 20,000 Hz
Sensitivity: 5W
Gross volume |: 25 liters
Woofer: 20cm
Phase link unit 8cm
Tweeter: 2.5cm
Dimensions W x H x D: 26 x 48 x 21cm
Weight 7 kg.
In this link WMTMW Baekgaard
I read that the 45th sounds terrible.
I disagree. I compare it with my B&W DM602 and find it very nice to beovox.
I do not know if they are better or worse in terms of characteristics, but to the ear they are very good
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In the link, the "sounds terrible (bad) by nowadays standard" opinion relates to the Beovox S45.
Since you have the highly regarded Beovox S45-2, you can ignore the above opinion.
Your renovation looks very nice and, in my opinion, you were right in using electrolytic capacitors to retain the original character of the loudspeaker.
Since you have the highly regarded Beovox S45-2, you can ignore the above opinion.
Your renovation looks very nice and, in my opinion, you were right in using electrolytic capacitors to retain the original character of the loudspeaker.
I had a pair of the 2s, the star of the show is the 10FM.
Flat over a decade, with smooth rolloff at both ends, it can be used so easily in many ways.(but small xmax, so not a low mid)
I ended up with a conventional 3way, 800/3k, pretty much L/R2.
The boards were fried, one tweeter dead, so I just started from scratch. Which made it much easier to go to 8ohm 10FMs when my nephew blew the originals by turning it up to 13.
Flat over a decade, with smooth rolloff at both ends, it can be used so easily in many ways.(but small xmax, so not a low mid)
I ended up with a conventional 3way, 800/3k, pretty much L/R2.
The boards were fried, one tweeter dead, so I just started from scratch. Which made it much easier to go to 8ohm 10FMs when my nephew blew the originals by turning it up to 13.
Useful piece of work, ALPUY. You have cleared up one of the mysteries of loudspeakers. 😀
The SEAS 4" mid is considered one of the better, flatter drivers and is a good choice.
We have a member here who likes Harsch two-way crossovers, which are supposed to be low on time delay too.
Troels investigated the SEAS 503 3 way. But clearly more conventional.
SEAS Kit 503