PSB Avantini Measurements

[spiral scratch]

Hey there, I have a pair of original Avantinis from like '74 or something. I was looking at the brochure and it's a bit muddled as far as specifications go. They are described as 90dB efficiency, but if you look at the criteria it's actually 90dB at 2 metres and 7 watts, so not really an appropriate gauge for the 1m/1w standard. From my basic research I gather a doubling of distance drops efficiency by 6dB, so then we're up to 96dB at one meter for these. Then it's a doubling of watts to get a 3dB rise, so 8 watts would add another 12 dB which I guess drops them down to about 84dB. I've seen formulas but I can't actually make any sense of them as my math isn't so great. Just wondering if anyone wants to take shot at figuring out their efficency at the more understandable 1m/1w standard.

They actually sound pretty good, but my current 30wpc integrated doesn't seem to have enough power to fill them out. If anyone has a suggestion for recommended power that would be helpful. They are being used in a smallish apartment in a room about 11'x15.5'. I rarely get them over 10 O'clock on the volume, but still think they need more juice to open up. I'm not planning on subs anytime soon, just want to enjoy them as they are.

Thanks for any assistance.

 

[NiagaraPete]

I remember those I sold mountains of them. You may be best to replace them before your amp. What is your amp BTW? We sold those with HK and Luxman mostly.

 

[staticV3]

7W -> 1W would reduce the output by 8.5dB.
2m -> 1m would increase output by 6dB, under free field conditions.

Ergo, PSB's spec of 90dB SPL/7W at 2m equals 87.5dB SPL/W at 1m.

 

[spiral scratch]

Thanks for that. That's better than I thought it was, but I also suspect my amplifier isn't helping here.

 

[Chrispy]

A nice calculator to use once you have typical spec http://www.hometheaterengineering.com/splcalculator.html

 

[Elkerton]

You might find this supportive.

 

[spiral scratch]

I remember those I sold mountains of them. You may be best to replace them before your amp. What is your amp BTW? We sold those with HK and Luxman mostly.

Well, they were a thrift store find so I could part with them without too much difficulty, but they're working and sound alright to me. I'm actually quite enjoying them. I'm using a Luxman LV-110 for power and it's rated 30wpc. I think that power might be a tad overstated and the amp is starting to fail, so I'm shopping for something else to replace it.

A nice calculator to use once you have typical spec http://www.hometheaterengineering.com/splcalculator.html

Thanks. It would indicate 95.7dB at my listening spot, so 30wpc should suffice.

You might find this supportive.

Thanks. It's funny how that 2Khz dip didn't show up in the PSB brochure.

 

[Elkerton]

I wouldn’t worry about that 20kHz dip. It’s likely beyond your hearing and, besides which, is off the main axis, though that one at 5kHz might be noticeable because it’s on the main. Fortunately, we are less sensitive to dips than bumps. As a thrift store find, you are a lucky man.

That Luxman is a good amp, and unless you play music Very loudly, should be fine. It’s a shame it’s starting to fail. How so?

 

[NiagaraPete]

Luxman LV-110 for power and it's rated 30wpc

That is a sweet amp and worth restoring if it is in descent visual condition.

The PSB’s re 50+- years old and not worth restoring. While they may still sound okay they don’t compare with modern offerings and are probably not near original spec.

 

[spiral scratch]

Yeh, I purchased the amp in '90 and it was my main amp for many years, now it's my fallback. It's in great shape cosmetically, puchased new and cared for. It's starting to lose the left channel intermittently. It plays fine for a spell and then the left channel starts to crackle and fade. It's been playing fine all day now, but I know it will cut out again eventually. Headphone out seems to be more susceptible to the same problem. There's someone in the area I might be able to ask about a service. My main repair technician died last fall, so I haven't been too keen to get stuff worked on since then.

I have a QED that was my main amp until I made a failed repair attempt. I preferred the sound of it to the Luxman, it was rated for 40wpc and just seemed to play with more authority but it was also prone to breakdown due to it's lack of protection circuits. It's in parts waiting for me to gather patience to make another attempt.

I was budgeting $200-$300 for a used replacement integrated, so maybe I'll get the Luxman serviced and see how much is left for speakers then. The Avantinis would likely not fetch much as they are functioning fine, but the cabinets are worse for wear. I took some windex to the vinyl veneer and it was surprising how much crud was in there.

 

[NiagaraPete]

Yeh, I purchased the amp in '90 and it was my main amp for many years, now it's my fallback. It's in great shape cosmetically, puchased new and cared for. It's starting to lose the left channel intermittently. It plays fine for a spell and then the left channel starts to crackle and fade. It's been playing fine all day now, but I know it will cut out again eventually. Headphone out seems to be more susceptible to the same problem. There's someone in the area I might be able to ask about a service. My main repair technician died last fall, so I haven't been too keen to get stuff worked on since then.

I have a QED that was my main amp until I made a failed repair attempt. I preferred the sound of it to the Luxman, it was rated for 40wpc and just seemed to play with more authority but it was also prone to breakdown due to it's lack of protection circuits. It's in parts waiting for me to gather patience to make another attempt.

I was budgeting $200-$300 for a used replacement integrated, so maybe I'll get the Luxman serviced and see how much is left for speakers then. The Avantinis would likely not fetch much as they are functioning fine, but the cabinets are worse for wear. I took some windex to the vinyl veneer and it was surprising how much crud was in there.

Honestly I have not listened to or bought any of the new d class amps. They seem affordable and spec well. I’d personally get the Lux fixed even if only used as a backup, it’s good gear.

Hard otherwise to advise you but it does seem to me that you’re done well with your gear but it’s time to replace and upgrade.

Depending on your source a simple DAC an active speakers will out perform your stuff 10 fold but you’d need to spend a bit.

 

[Elkerton]

That is a sweet amp and worth restoring if it is in descent visual condition.

The PSB’s re 50+- years old and not worth restoring. While they may still sound okay they don’t compare with modern offerings and are probably not near original spec.

Hey, Pete,
You'd be surprised by how well those old PSBs perform despite their age. Those Philips drivers age well. I was a PSB rep from '80 to '82, and still own and use a pair of the original Alphas, which were a car loudspeaker, on my wife's TV because they sound so much better that the TV's sound system, a pair of Avantes in a studio, and 2 original SUBWOOFERs (PSB's nomenclature haha) in my main system to most people's deep bass enjoyment. Don't be too quick to write off old speakers. Many hold up Very well.

 

[Elkerton]

About the Luxman, is it possible that it may have a dirty switch, or two? I use at least 2 old products whose switches I have to spray with electrical cleaner now and then because the sound begins to break up, buzz, or stop completely. A temporary fix is to turn the switch on and off many times to rub the contacts clean.

 

[spiral scratch]

About the Luxman, is it possible that it may have a dirty switch, or two? I use at least 2 old products whose switches I have to spray with electrical cleaner now and then because the sound begins to break up, buzz, or stop completely. A temporary fix is to turn the switch on and off many times to rub the contacts clean.

Yeh thanks for the suggestions. After Pete's cajoling I decided to open it up. I had a few internet searches that described the speaker relay as a possible culprit. The relay would not open for me with a bit of gentle prying so that's a no go. I did take the opportunity to clean all the plugs and jacks on the back panel. I'll need to open the front panel at some point to access and clean the switches. It was pretty dusty inside, not likely opened since the day I brought it home. Anyways, I'll see what the tech has to tell me. It's all working now, making pleasant sounds as I write. Not sure how easy it would be be to remedy something that occurs so erratically.

These Avantinis look like an early production run with hexagonal cutouts for the driver and tweeter mounted on the panel exterior. The grills aren't beveled as described in the brochure. A felt surround might be in order as they do exhibit a bit of edginess in the treble at times. Maybe not the last word in refinement, but they generally do sound pretty balanced to me. I was a bit surprised by that when I first played them.

 

[Elkerton]

Yes, an early version with the octagonal woofer, probably between ‘75 and ‘77. While the bevel is useful on later models, reducing diffraction at the edges, felt around the tweeter is perhaps more important. I once cut felt insoles up to place around the tweeters of other tweeters, but any cloth might do: a wee towel folded up, a hand cloth, and attached to the baffle. You have an advantage I believe that the grill would cover such embellishments. Currently, I have folded hand towels and laid them on top of my Revel M105s so that they hang down the sides. I haven’t yet tried to fashion the thin felt I have to do the same in a perhaps more aesthetically pleasing fashion.

 

[spiral scratch]

I took some contact cleaner and Fader Lube to the knobs and switches on the Luxman. Also cleaned all of the jacks on the back and headphone out. It’s been running for few days now with nary a problem, so thanks for the inspiration to give it a clean. It should really be No.2 on my troubleshooting list, right after check cable connections.

I picked up some felt boot liners and carpet tape at the dollar store to make some donuts to tame the tweeters. So far, so good. Now I just need to find a couple of 2ft stands.

Thanks for all the input and neat info on these speakers. Those Paisleys also measure well. Another NCR builder I would assume. I’ve been reading up a bit on him now too. He seems to have quite a reputation for building nice speakers.

 

[Elkerton]

Wow! Very cool.