Advent Legacy II

[alhere]

Does anyone have specs for the tweeters in the Legacy II?
I'm replacing the woofers and the crossovers. Solen.ca need tweeter specs to build the crossovers. Proposing a new Scanspeak 10 inch woofer. Haven't decided on anything yet, since I barely know what i'm doing, or how far to go for better sound.

Any advice greatly appreciated.

Go canuck.

 

[swechsler]

Since you're going with a cabinet with a fixed volume, model whatever woofer you think you'd like to use before purchasing, using some speaker design software (WinISD is the one I usually use). You can probably infer the sensitivity of the tweeter via the specs of the loudspeaker as a whole. I couldn't find the crossover frequency of the II; the original Legacy crossover over a 2.5khz. You can probably infer the frequency by examining the crossover. So whatever woofer you choose needs to be flat up to that point.

 

[WillMeyer]

I have a pair of Advent Legacy I's.
I've refoamed the woofer, replaced the terminal block with one from a Advent Heritage (5-way binding post and fuse), and update the caps to poly.
Attached is a schematic of the crossover as well as a couple of pics.
I'm currently refinishing the wood so my speakers are still in work.
I'm certain the crossover is the same between the I and the II. The tweeters are different, but I suspect it might just be the housing.
The tweeter on the I is wider than tall, the II is taller than wide.
I hope this is a help.

 

[alhere]

Since you're going with a cabinet with a fixed volume, model whatever woofer you think you'd like to use before purchasing, using some speaker design software (WinISD is the one I usually use). You can probably infer the sensitivity of the tweeter via the specs of the loudspeaker as a whole. I couldn't find the crossover frequency of the II; the original Legacy crossover over a 2.5khz. You can probably infer the frequency by examining the crossover. So whatever woofer you choose needs to be flat up to that point.

Thanks, this is very helpful. I have been using cutout diameter and budget as my main criteria for selecting a woofer! This software should help to check on speaker suitability. The spec sheet for Legacy II shows Crossover frequency of 2000 Hz and Impedance of 6 ohms (nominal) and 4 ohms (minimum), Useable frequency range of low = 30 Hz, -8 dB; high+ 23 kHz, -3 dB; Sensitivity (2.8V@1m) = 90dB. Tweeter: 1" Ferrofluid filled parabolic soft dome.

For crossover replacement, how can I infer the specific tweeter impedance? The current crossover doesn't give me much to infer from (see photo).
Thanks for any advice.

 

[alhere]

I have a pair of Advent Legacy I's.
I've refoamed the woofer, replaced the terminal block with one from a Advent Heritage (5-way binding post and fuse), and update the caps to poly.
Attached is a schematic of the crossover as well as a couple of pics.
I'm currently refinishing the wood so my speakers are still in work.
I'm certain the crossover is the same between the I and the II. The tweeters are different, but I suspect it might just be the housing.
The tweeter on the I is wider than tall, the II is taller than wide.
I hope this is a help.

Thanks for the information and photos. I will check on the crossover components under all the glue. It's hard to find a terminal block with upgraded binding posts that fits the Legacy II cutout.

 

[RTally]

Thanks, this is very helpful. I have been using cutout diameter and budget as my main criteria for selecting a woofer! This software should help to check on speaker suitability. The spec sheet for Legacy II shows Crossover frequency of 2000 Hz and Impedance of 6 ohms (nominal) and 4 ohms (minimum), Useable frequency range of low = 30 Hz, -8 dB; high+ 23 kHz, -3 dB; Sensitivity (2.8V@1m) = 90dB. Tweeter: 1" Ferrofluid filled parabolic soft dome.

For crossover replacement, how can I infer the specific tweeter impedance? The current crossover doesn't give me much to infer from (see photo).
Thanks for any advice.

You cannot infer driver impedance. Nor can you use nominal impedance for crossover design. What matters is the specific impedance of the driver at the crossover frequency. But since driver impedance varies over the driver's frequency range, that impedance needs to be taken from either a published impedance vs. frequency curve or be measured. Measuring driver impedance is not difficult. There is free software (REW is one) that can be used with minimal equipment (resistor).
https://www.roomeqwizard.com/help/help_en-GB/html/impedancemeasurement.html

 

[alhere]

Thanks!

 

[WillMeyer]

If you look on ebay, occationally you can find Advent Hertitage terminal blocks. They are physically the same size as the legacy and will fit the cutout perfectly. Another alternative is to get a couple of 5-way binding posts and mount them on the Legacy terminal block. You can wire them up instead (or in conjuction with) the stock terminals. I did that with a set of Advent Laureates and they came out real nice.

 

[swechsler]

You cannot infer driver impedance. Nor can you use nominal impedance for crossover design. What matters is the specific impedance of the driver at the crossover frequency. But since driver impedance varies over the driver's frequency range, that impedance needs to be taken from either a published impedance vs. frequency curve or be measured.
https://www.roomeqwizard.com/help/help_en-GB/html/impedancemeasurement.html

Yup, and I completely forgot about this. But you (@alhere) now know the crossover frequency. The existing crossover was a first order (6dB/octave) design, very simple. It would probably be easiest to use the same type of crossover when you replace the woofer, just choose the inductor for a 2000hz low pass based on the impedance graph of the woofer you decide on (Parts Express posts the impedance graph of many, but not all of they sell). You can use the same capacitor, although considering its age, you'd probably be best off replacing it with a newer one of the same value. Assuming you're happy with the 2khz crossover, you don't need to know the tweeters impedance, you just assume that the original cap is appropriate for that tweeter.

 

[elitopus]

Sorry if you already explained it and I missed it somehow, but why are you replacing the woofers and crossovers? The originals are blown, missing, or you just want to upgrade?

These speakers stock are supposed to be pretty decent. I have a pair myself that need a refoam, but I’ve never listened to them.

 

[alhere]

If you look on ebay, occationally you can find Advent Hertitage terminal blocks. They are physically the same size as the legacy and will fit the cutout perfectly. Another alternative is to get a couple of 5-way binding posts and mount them on the Legacy terminal block. You can wire them up instead (or in conjuction with) the stock terminals. I did that with a set of Advent Laureates and they came out real nice.

Thanks, I will try some new binding posts on the existing terminal block.

 

[alhere]

Yup, and I completely forgot about this. But you (@alhere) now know the crossover frequency. The existing crossover was a first order (6dB/octave) design, very simple. It would probably be easiest to use the same type of crossover when you replace the woofer, just choose the inductor for a 2000hz low pass based on the impedance graph of the woofer you decide on (Parts Express posts the impedance graph of many, but not all of they sell). You can use the same capacitor, although considering its age, you'd probably be best off replacing it with a newer one of the same value. Assuming you're happy with the 2khz crossover, you don't need to know the tweeters impedance, you just assume that the original cap is appropriate for that tweeter.

.... There on the Parts Express database of discontinued items are the specs for the Advent Legacy II tweeter! Nice surprise.
https://www.parts-express.com/advent-099-20167-1-mylar-dome-tweeter--299-2010#lblProductDetails
I will probably get Solen to build me the crossovers. Thanks for the advice on woofer selection criteria.

 

[alhere]

Sorry if you already explained it and I missed it somehow, but why are you replacing the woofers and crossovers? The originals are blown, missing, or you just want to upgrade?

These speakers stock are supposed to be pretty decent. I have a pair myself that need a refoam, but I’ve never listened to them.

I'm trying to improve the sound, maybe because I have time on my hands and a large neglected record collection. I reformed them but I don't really like the overall clarity with jazz music, especially with an occasional high end crackle with the left speaker. Something with the alignment of refoaming, or some other mystery or maybe not enough speaker break-in time. It may otherwise be ok if I wasn't listening so carefully in pandemic isolation. I haven't quite decided how much to spend on new woofers to get a sound that I really like. It may be that just replacing the old crossovers will make a difference.

 

[WillMeyer]

The electrolytic capacitors may cause a crackle when they go bad. I noticed it with a set of Altecs. The problem went away when I recapped them.

The Advent Legacy has zero components in the crossover for the woofer. I was very suprised when I opened up mine and I sketched out the crossover.

There are 2 caps in the tweeter circuit. Given the age of the speakers and the lifecycle of electrolytic caps, there is a high probability that a bad cap is causing your crackle from the tweeter circuit. Updating them with film caps is a good upgrade and relatively inexpensive. Solen makes a great cap. I typically use Solen and Audyn caps, but any film cap will be a major improvement over the electrolytics.

Be aware film caps need to break-in. You might be disappointed when you apply first power, but they will smooth out after a few hours. The more you play them, the better they'll sound. Some sites claim 250 hrs to fully break in - I can't atest to that but I typically run my upgrades 2 days straight (mostly at very low volumes), to keep the caps charging/discharging. It seems to work well for me.

 

[alhere]

The electrolytic capacitors may cause a crackle when they go bad. I noticed it with a set of Altecs. The problem went away when I recapped them.

The Advent Legacy has zero components in the crossover for the woofer. I was very suprised when I opened up mine and I sketched out the crossover.

There are 2 caps in the tweeter circuit. Given the age of the speakers and the lifecycle of electrolytic caps, there is a high probability that a bad cap is causing your crackle from the tweeter circuit. Updating them with film caps is a good upgrade and relatively inexpensive. Solen makes a great cap. I typically use Solen and Audyn caps, but any film cap will be a major improvement over the electrolytics.

Be aware film caps need to break-in. You might be disappointed when you apply first power, but they will smooth out after a few hours. The more you play them, the better they'll sound. Some sites claim 250 hrs to fully break in - I can't atest to that but I typically run my upgrades 2 days straight (mostly at very low volumes), to keep the caps charging/discharging. It seems to work well for me.

 

[alhere]

Thanks for your advice.

 

[elitopus]

I would definitely recap them and listen before you start replacing drivers and xovers. The Advent woofers have always been their strong suit IMO.

 

[mhardy6647]

The Legacy II has zero panache -- but they ain't bad at all.

109 by Mark Hardy, on Flickr
113 by Mark Hardy, on Flickr

 

[alhere]

I would definitely recap them and listen before you start replacing drivers and xovers. The Advent woofers have always been their strong suit IMO.

That's very good advice especially given the cost on new woofers. I did a listening test on each speaker and it is only the left speaker low end crackle that is a distinct problem. I assume that this may be due to a mis-centered surround replacement (not sure how to diagnose this) or the speaker cone is damaged. Looking carefully, neither are visible problems. Or the crossover is blown on the left speaker. I will replace crossovers as per Solen specs and see if it resolves the problem.

 

[swechsler]

Before you do anything:

1. Swap the woofers between the cabinets and see if the problem stays with the cabinet or moves with the woofer. That will rule out either the crossover or the woofer
2. If it turns out that the woofer is the problem, push in gently on the cone while listening carefully. Do you hear any scraping? If not, then the problem is likely that something is vibrating. This could be the surround, dust cap, spider, or the point where the voice coil attaches to the cone. Examine each part of the driver carefully to see if anything is loose. It may not be obvious; it doesn't take much to make extraneous noise, and it may not be visible at all unless you physically handle it.