[nickbatz]

Happy New Year.

So I just dumpster-dived a pair of mid-'80s (guessing) RS Sierra tower speakers from a neighbor.

This is a premature question because I haven't hooked them up yet, but they have 12" rear-firing passive radiators with totally shot foam surrounds.

Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

My guess is that these are hyped speakers, because I know Rogersound Labs and other stereo stores used to compare speakers to JBL L100s in those days. But the tweeter, midrange, and woofer are outwardly in good shape. The cabinets are in reasonable shape, but because I've been doing a lot of woodworking* recently I can easily replace some of the walnut veneer if it's necessary.

TIA

* By the way, if anyone knows anyone in the market for custom studio furniture, especially a unique composer's desk, let me know and and I'll send you some pictures. This has become a serious side business - I just shipped a desk to Paris, another to Florida - and I'm truly enjoying it.

[nickbatz]

https://www.amazon.com/ESS-Speaker-P.../dp/B009DNMZ6M

For example

[nickbatz]

I'm thinking $3 foam surrounds from ebay would probably do the job, right? No need for the Italian silk ones with solid gold mounting hardware?

[Mike Rivers[_2_]]

On 1/4/2020 9:21 PM, nickbatz wrote:
Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

A passive radiator is just a driver without the motor. When you get an
"edge kit" you leave the original cone in place, so you don't have to
worry about matching the cone mass and stiffness, they thing that should
match the original is the stiffness of the suspension.

I have some Advent speakers that had foam rot. I'd never worked on a
speaker before so I was hesitant to operate on them, but figured that
for ten bucks or so I'd give it a try. It worked out just fine. The
hardest part is to get all the the old glue off the frame where the
suspension is attached.

I got my kit from Simply Speakers. Their web site gave me enough
confidence that I could do the job, and they were helpful with some
pre-purchase questions. You might take a look and see if they already
know what you need and can supply it.

https://www.simplyspeakers.com/ of course.



--
For a good time, call http://mikeriversaudio.wordpress.com

[Scott Dorsey]

In article , Mike Rivers wrote:
On 1/4/2020 9:21 PM, nickbatz wrote:
Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

A passive radiator is just a driver without the motor. When you get an
"edge kit" you leave the original cone in place, so you don't have to
worry about matching the cone mass and stiffness, they thing that should
match the original is the stiffness of the suspension.

A lot of passive radiators, though, have the stiffness entirely the result
of the surround; there is no spider, no other suspension and so consequently
the surround has to be constructed differently and the surround needs to
be selected properly for the driver.

I have some Advent speakers that had foam rot. I'd never worked on a
speaker before so I was hesitant to operate on them, but figured that
for ten bucks or so I'd give it a try. It worked out just fine. The
hardest part is to get all the the old glue off the frame where the
suspension is attached.

In the case of speakers, the stiffness is mostly the result of the spider,
so you can swap out the surround with impunity without affecting the
driver Fs appreciably.

I got my kit from Simply Speakers. Their web site gave me enough
confidence that I could do the job, and they were helpful with some
pre-purchase questions. You might take a look and see if they already
know what you need and can supply it.

https://www.simplyspeakers.com/ of course.

Passive radiators aren't expensive. The stiffness on them varies. If it
were me, I'd get one of every kind that Madisound sells, try them in turn,
and see which one gives most accurate low end. Then I'd buy a second one
of that model for the other speaker.

Somebody who actually knows those speakers can likely do better, and it's
possible some place like Simply Speakers or the Speaker Factory in
Gathersburg, MD might know them.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Trevor]

On 6/01/2020 12:53 am, Scott Dorsey wrote:
In article , Mike Rivers wrote:
On 1/4/2020 9:21 PM, nickbatz wrote:
Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

A passive radiator is just a driver without the motor. When you get an
"edge kit" you leave the original cone in place, so you don't have to
worry about matching the cone mass and stiffness, they thing that should
match the original is the stiffness of the suspension.

A lot of passive radiators, though, have the stiffness entirely the result
of the surround; there is no spider, no other suspension and so consequently
the surround has to be constructed differently and the surround needs to
be selected properly for the driver.

I have some Advent speakers that had foam rot. I'd never worked on a
speaker before so I was hesitant to operate on them, but figured that
for ten bucks or so I'd give it a try. It worked out just fine. The
hardest part is to get all the the old glue off the frame where the
suspension is attached.

In the case of speakers, the stiffness is mostly the result of the spider,
so you can swap out the surround with impunity without affecting the
driver Fs appreciably.

I got my kit from Simply Speakers. Their web site gave me enough
confidence that I could do the job, and they were helpful with some
pre-purchase questions. You might take a look and see if they already
know what you need and can supply it.

https://www.simplyspeakers.com/ of course.

Passive radiators aren't expensive. The stiffness on them varies. If it
were me, I'd get one of every kind that Madisound sells, try them in turn,
and see which one gives most accurate low end. Then I'd buy a second one
of that model for the other speaker.


A lot of passive radiators are tuned by adding mass to the cone. So if
you can measure the bass response, it will be cheaper to simply adjust
the cone mass. Cheaper still to throw away the PR and tune the box with
a port.

[nickbatz]

On Tuesday, January 7, 2020 at 8:05:09 PM UTC-8, Trevor wrote:

A lot of passive radiators are tuned by adding mass to the cone. So if
you can measure the bass response, it will be cheaper to simply adjust
the cone mass. Cheaper still to throw away the PR and tune the box with
a port.

That's beyond my ken.

I mean, I can measure the bass response, but I have NFI how to tune the box with a port.

[Don Pearce[_3_]]

On Wed, 8 Jan 2020 11:08:42 -0800 (PST), nickbatz
wrote:

On Tuesday, January 7, 2020 at 8:05:09 PM UTC-8, Trevor wrote:

A lot of passive radiators are tuned by adding mass to the cone. So if
you can measure the bass response, it will be cheaper to simply adjust
the cone mass. Cheaper still to throw away the PR and tune the box with
a port.

That's beyond my ken.

I mean, I can measure the bass response, but I have NFI how to tune the box with a port.

The software will do that for you.

d

[gregz]

nickbatz wrote:
On Tuesday, January 7, 2020 at 8:05:09 PM UTC-8, Trevor wrote:

A lot of passive radiators are tuned by adding mass to the cone. So if
you can measure the bass response, it will be cheaper to simply adjust
the cone mass. Cheaper still to throw away the PR and tune the box with
a port.

That's beyond my ken.

I mean, I can measure the bass response, but I have NFI how to tune the box with a port.

Port or passive start out measuring impedance. The passive or port will
reduce woofer excursion over most of the low bass range, to almost none.
Selecting a frequency say around 50 Hz, putting hand near port will make
woofer move more. Adding some sticky gum to passive will do same thing. I
would first measure passive resonant frequency to see if it's proper. You
can visual tune very close to same watching impedance plots. Converting to
port is not always possible. Some of the other aspects get complicated, as
I read a very nice write up on the subject, beyond what I wanted to see.

Greg

[Les Cargill[_4_]]

nickbatz wrote:
On Tuesday, January 7, 2020 at 8:05:09 PM UTC-8, Trevor wrote:

A lot of passive radiators are tuned by adding mass to the cone. So if
you can measure the bass response, it will be cheaper to simply adjust
the cone mass. Cheaper still to throw away the PR and tune the box with
a port.

That's beyond my ken.

I mean, I can measure the bass response, but I have NFI how to tune the box with a port.


WinISD will allow you to play with this to your heart's content.

--
Les Cargill

[Don Pearce[_3_]]

On Sat, 4 Jan 2020 18:21:29 -0800 (PST), nickbatz
wrote:

Happy New Year.

So I just dumpster-dived a pair of mid-'80s (guessing) RS Sierra tower speakers from a neighbor.

This is a premature question because I haven't hooked them up yet, but they have 12" rear-firing passive radiators with totally shot foam surrounds.

Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

My guess is that these are hyped speakers, because I know Rogersound Labs and other stereo stores used to compare speakers to JBL L100s in those days. But the tweeter, midrange, and woofer are outwardly in good shape. The cabinets are in reasonable shape, but because I've been doing a lot of woodworking* recently I can easily replace some of the walnut veneer if it's necessary.

TIA

* By the way, if anyone knows anyone in the market for custom studio furniture, especially a unique composer's desk, let me know and and I'll send you some pictures. This has become a serious side business - I just shipped a desk to Paris, another to Florida - and I'm truly enjoying it.

If you have the TS parameters for the main driver, you can probably
design a port that will allow you to do away with the stupid passive
radiator. They are no more than a spring and a mass, just the same as
air in a port tube, but suffer added non-linearity due to the
suspension. Any subwoofer design software will let you do this.

d

[Les Cargill[_4_]]

Don Pearce wrote:
On Sat, 4 Jan 2020 18:21:29 -0800 (PST), nickbatz
wrote:

Happy New Year.

So I just dumpster-dived a pair of mid-'80s (guessing) RS Sierra tower speakers from a neighbor.

This is a premature question because I haven't hooked them up yet, but they have 12" rear-firing passive radiators with totally shot foam surrounds.

Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

My guess is that these are hyped speakers, because I know Rogersound Labs and other stereo stores used to compare speakers to JBL L100s in those days. But the tweeter, midrange, and woofer are outwardly in good shape. The cabinets are in reasonable shape, but because I've been doing a lot of woodworking* recently I can easily replace some of the walnut veneer if it's necessary.

TIA

* By the way, if anyone knows anyone in the market for custom studio furniture, especially a unique composer's desk, let me know and and I'll send you some pictures. This has become a serious side business - I just shipped a desk to Paris, another to Florida - and I'm truly enjoying it.

If you have the TS parameters for the main driver, you can probably
design a port that will allow you to do away with the stupid passive
radiator. They are no more than a spring and a mass, just the same as
air in a port tube, but suffer added non-linearity due to the
suspension. Any subwoofer design software will let you do this.

d


Would WinISD be a good choice for this, Don? That's where I'd go first.

--
Les Cargill

[Don Pearce[_3_]]

On Sun, 5 Jan 2020 13:24:36 -0600, Les Cargill
wrote:

Don Pearce wrote:
On Sat, 4 Jan 2020 18:21:29 -0800 (PST), nickbatz
wrote:

Happy New Year.

So I just dumpster-dived a pair of mid-'80s (guessing) RS Sierra tower speakers from a neighbor.

This is a premature question because I haven't hooked them up yet, but they have 12" rear-firing passive radiators with totally shot foam surrounds.

Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

My guess is that these are hyped speakers, because I know Rogersound Labs and other stereo stores used to compare speakers to JBL L100s in those days. But the tweeter, midrange, and woofer are outwardly in good shape. The cabinets are in reasonable shape, but because I've been doing a lot of woodworking* recently I can easily replace some of the walnut veneer if it's necessary.

TIA

* By the way, if anyone knows anyone in the market for custom studio furniture, especially a unique composer's desk, let me know and and I'll send you some pictures. This has become a serious side business - I just shipped a desk to Paris, another to Florida - and I'm truly enjoying it.

If you have the TS parameters for the main driver, you can probably
design a port that will allow you to do away with the stupid passive
radiator. They are no more than a spring and a mass, just the same as
air in a port tube, but suffer added non-linearity due to the
suspension. Any subwoofer design software will let you do this.

d


Would WinISD be a good choice for this, Don? That's where I'd go first.

WinISD is fine. You can put in the dimensions of your box, and let it
design the port.

d

[Mat Nieuwenhoven]

On Sun, 05 Jan 2020 14:12:19 GMT, Don Pearce wrote:

On Sat, 4 Jan 2020 18:21:29 -0800 (PST), nickbatz
wrote:

Happy New Year.

So I just dumpster-dived a pair of mid-'80s (guessing) RS Sierra tower speakers from a neighbor.

This is a premature question because I haven't hooked them up yet, but they have 12" rear-firing passive radiators with totally shot foam surrounds.

Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

My guess is that these are hyped speakers, because I know Rogersound Labs and other stereo stores used to compare speakers to JBL L100s in those days. But the tweeter, midrange, and woofer are outwardly in good shape. The cabinets are in reasonable shape, but because I've been doing a lot of woodworking* recently I can easily replace some of the walnut veneer if it's necessary.

TIA

* By the way, if anyone knows anyone in the market for custom studio furniture, especially a unique composer's desk, let me know and and I'll send you some pictures. This has become a serious side business - I just shipped a desk to Paris, another to Florida - and I'm truly enjoying it.

If you have the TS parameters for the main driver, you can probably
design a port that will allow you to do away with the stupid passive
radiator. They are no more than a spring and a mass, just the same as
air in a port tube, but suffer added non-linearity due to the
suspension. Any subwoofer design software will let you do this.

A passive radiator is designed to match the main driver and do away
with the port. A port works fine at low volumes, but if a lot of air
needs to move it suffers from compression problems, especially if the
port is longer. Plus mid-range leakage if it is at the front. A
passive radiator does not have distortion problem any more than the
matching main driver, and can be the only solution if the port would
otherwise become too long.

Mat Nieuwenhoven

[Don Pearce[_3_]]

On Mon, 06 Jan 2020 08:05:27 +0100 (CET), "Mat Nieuwenhoven"
wrote:

On Sun, 05 Jan 2020 14:12:19 GMT, Don Pearce wrote:

On Sat, 4 Jan 2020 18:21:29 -0800 (PST), nickbatz
wrote:

Happy New Year.

So I just dumpster-dived a pair of mid-'80s (guessing) RS Sierra tower speakers from a neighbor.

This is a premature question because I haven't hooked them up yet, but they have 12" rear-firing passive radiators with totally shot foam surrounds.

Assuming it's worth fixing them - if only to trade someone for something else - is it likely to make any serious difference what round 12" cone-shaped thing I put back there? Serious = commensurate with the quality of these speakers.

My guess is that these are hyped speakers, because I know Rogersound Labs and other stereo stores used to compare speakers to JBL L100s in those days. But the tweeter, midrange, and woofer are outwardly in good shape. The cabinets are in reasonable shape, but because I've been doing a lot of woodworking* recently I can easily replace some of the walnut veneer if it's necessary.

TIA

* By the way, if anyone knows anyone in the market for custom studio furniture, especially a unique composer's desk, let me know and and I'll send you some pictures. This has become a serious side business - I just shipped a desk to Paris, another to Florida - and I'm truly enjoying it.

If you have the TS parameters for the main driver, you can probably
design a port that will allow you to do away with the stupid passive
radiator. They are no more than a spring and a mass, just the same as
air in a port tube, but suffer added non-linearity due to the
suspension. Any subwoofer design software will let you do this.

A passive radiator is designed to match the main driver and do away
with the port. A port works fine at low volumes, but if a lot of air
needs to move it suffers from compression problems, especially if the
port is longer. Plus mid-range leakage if it is at the front. A
passive radiator does not have distortion problem any more than the
matching main driver, and can be the only solution if the port would
otherwise become too long.

Mat Nieuwenhoven



None of those "problems" is actually a problem. The passive driver is
just another piece of stuff to introduce its own problems.

d

[nickbatz]

Speaking of Mike's AR speakers, my theory is that big - with big boxes - ported speakers (including passive radiator designs) are capable of producing a more natural-sounding low end than sealed/acoustic suspension ones.

That's the main thing I like about my UREI monitors, warts and all: the low end just sounds overwhelmingly right. I suspect it has to do with acoustic compression making smaller speakers sound more like the sound is coming from a box.Maybe it's more than just the low end, it could be the lower mids too.

Now, I also have a Blue Sky System One setup - two sealed sats + a sub. They're much better for working on, and the sub goes all the way down. And they're really good, and nice to listen to.

But I can't help thinking that even though the NFM concept has been unquestioned for at least 40 years, there's still something you can only get from big-ass monitors.

[Don Pearce[_3_]]

On Mon, 6 Jan 2020 12:58:46 -0800 (PST), nickbatz
wrote:

Speaking of Mike's AR speakers, my theory is that big - with big boxes - ported speakers (including passive radiator designs) are capable of producing a more natural-sounding low end than sealed/acoustic suspension ones.

That's the main thing I like about my UREI monitors, warts and all: the low end just sounds overwhelmingly right. I suspect it has to do with acoustic compression making smaller speakers sound more like the sound is coming from a box.Maybe it's more than just the low end, it could be the lower mids too.

Now, I also have a Blue Sky System One setup - two sealed sats + a sub. They're much better for working on, and the sub goes all the way down. And they're really good, and nice to listen to.

But I can't help thinking that even though the NFM concept has been unquestioned for at least 40 years, there's still something you can only get from big-ass monitors.

I have decent large-ish sonus-faber speakers for mains and a 50 cubic
foot sub with a 15 inch Adire driver in it. That makes for very
relaxed bottom end, particularly as it is all integrated with
Sonarworks, which is so far the only software I know that measures
multiple (37) points in the room so it doesn't try to correct moding
nulls.

d

[nickbatz]

Okay, thanks very much everyone.

I have to listen and to get an idea of how much energy these speakers warrant putting into repairing them. It's not like I don't already have a bunch of very good ones.

Mike, I'm definitely not afraid to work on drivers - I even have a heat gun and glue, etc. But I'll have to see whether it's possible to salvage the cones. I only looked at them briefly and have been out all day.

My sense is that replacing the foam with similar foam will be close enough, same with the cones if necessary.

[Mike Rivers[_2_]]

On 1/5/2020 9:43 PM, nickbatz wrote:
I have to listen and to get an idea of how much energy these speakers warrant putting into repairing them. It's not like I don't already have a bunch of very good ones.

I really wish I could be more selective and brutal about what I keep. I
have a growing pile of non-working, semi-working, or
works-but-obsolete-and-has-already-been-functionally-replaced stuff -
useful, too nice to throw away, but questionable as to whether it's
worth the bother, time, and money to bring back to life.

I guess they'll go to the landfill along with me after I check out.

--
For a good time, call http://mikeriversaudio.wordpress.com

[Scott Dorsey]

In article , Mike Rivers wrote:
On 1/5/2020 9:43 PM, nickbatz wrote:
I have to listen and to get an idea of how much energy these speakers warrant putting into repairing them. It's not like I don't already have a bunch of very good ones.

I really wish I could be more selective and brutal about what I keep. I
have a growing pile of non-working, semi-working, or
works-but-obsolete-and-has-already-been-functionally-replaced stuff -
useful, too nice to throw away, but questionable as to whether it's
worth the bother, time, and money to bring back to life.

I guess they'll go to the landfill along with me after I check out.

They will wind up at the Manassas Hamfest.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Michael Beacom[_4_]]

On 2020-01-06 17:50:57 +0000, Scott Dorsey said:

In article , Mike Rivers wrote:
On 1/5/2020 9:43 PM, nickbatz wrote:
I have to listen and to get an idea of how much energy these speakers
warrant putting into repairing them. It's not like I don't already have
a bunch of very good ones.

I really wish I could be more selective and brutal about what I keep. I
have a growing pile of non-working, semi-working, or
works-but-obsolete-and-has-already-been-functionally-replaced stuff -
useful, too nice to throw away, but questionable as to whether it's
worth the bother, time, and money to bring back to life.

I guess they'll go to the landfill along with me after I check out.

They will wind up at the Manassas Hamfest.
--scott

When is the Manassas Hamfest?
Havn't been to one in too long.
Cheers
Mike

[Mike Rivers[_2_]]

On 1/7/2020 11:33 PM, Michael Beacom wrote:
When is the Manassas Hamfest?

https://w4ovh.net/welcome-to-manassas-hamfest/

June 13 this year. ARRL.org has a hamfest calendar on line

--
For a good time, call http://mikeriversaudio.wordpress.com

[Scott Dorsey]

Michael Beacom wrote:

When is the Manassas Hamfest?
Havn't been to one in too long.

June 13.

The next regional one would be the Richmond Frostfest on Feb 1. I think it's
actually bigger than Manassas these days although the weather is much worse.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[nickbatz]

On Monday, January 6, 2020 at 7:35:21 AM UTC-8, Mike Rivers wrote:

I really wish I could be more selective and brutal about what I keep.

We had rats in the garage two summers ago, which - because they're prolific - meant that everything in there had to be taken out and cleaned before being put back.

It took me and three other big guys a very long day, and I filled an entire construction trailer all the way up - you know, maybe 8' x 15' x 8' high - plus the back of the big pickup truck that hauled it - with 25 years of clutter.

Among my favorite throwings away were broken cassette decks, some old computers, two broken stereo receivers, one broken amp, some old printers, and my absolute favorite: three @#$)(@#$!!! laser printers (two to cannibalize for parts for the first) that invariably ended up with paper thrown away and toner all over the place.

I still have boxes of cables I'll never use. Who knows what's in all the cartons I didn't take the time to go through. Probably a couple of useful things.

But I'll either fix these speakers or get rid of them. They're too big to pile in the garage.

[Mike Rivers[_2_]]

On 1/6/2020 3:43 PM, nickbatz wrote:
But I'll either fix these speakers or get rid of them. They're too big to pile in the garage.

That's pretty much the same as what I say to myself when I put something
on the pile of things to fix. Trouble is that there doesn't seem to be a
statute of limitations for broken things to remain broken. It's a
benefit and a curse of living alone.


--
For a good time, call http://mikeriversaudio.wordpress.com

[Michael Beacom[_4_]]

On 2020-01-06 15:35:17 +0000, Mike Rivers said:

On 1/5/2020 9:43 PM, nickbatz wrote:
I have to listen and to get an idea of how much energy these speakers
warrant putting into repairing them. It's not like I don't already have
a bunch of very good ones.

I really wish I could be more selective and brutal about what I keep. I
have a growing pile of non-working, semi-working, or
works-but-obsolete-and-has-already-been-functionally-replaced stuff -
useful, too nice to throw away, but questionable as to whether it's
worth the bother, time, and money to bring back to life.

I guess they'll go to the landfill along with me after I check out.

And let the mermaids flirt with you?
(https://weeniecampbell.com/wiki/inde..._Flirt_With_Me)


I'd offer to help with the stuff, but suffer from the same affliction.

Cheers
Mike