Hello,
I got this old set of Altec Lansing Model "three", from yard sale for $10..
The original woofers were replaced with two different models/mfg of woofers.
I know this is not good, so I want some advise as to choosing replacement woofers.
So I pulled them apart, they are two-ways with 10" woofer( 4-bolt pattern) and a 110mm tweeter. I can not find any information on these replacement woofers, one being a "Blaster" and the other a "ONPA"
I also figured out the cross-over, it is 1 pole for the woofer, I measure 1.62mH/0.23ohm, a small unit with a steel lamination. I know this is not very good either.
The tweeter ckt is 2-pole with 8uF in series with 2 ohms, followed by a 0.28mH/0.27 ohm, air wound coil to ground, then a 8 ohm L-pad to the tweeter.
So to start with I did a sim of the cross-over in ltspice, just to get an idea. I used the standard equivalent of a woofer as published in Bob Cordell's PA book.
For the tweeter I ordered a new tweeter from Madisound as Morel's were on special, so I bought two of MDT-32S. I have used Morel's in other speakers and I like this brand.
I used the 10KHz Z spec's for the Morel tweeter in the cross-over sim (90uH in series with 5.2 ohms)
I get a cross-over point around 1.8KHz, which seems to be fine for this setup, I think.
The box measures internally, 22.5"x11"x8.25" for 1.2 cu ft or 33.6L. The port is 2 3/8" W x 3 1/4" depth.
The BIG ? now, is, how do I go about replacing these woofers with something that matches the existing box?
I do not currently have any box design software. I guess I can get out the old Vance Dickerson LS design book and give it another read, figure out/measure, the existing woofer spec's and see how they would perform.
Any ideas, recommendations would be greatly appreciated.
Thanks
Rick
I got this old set of Altec Lansing Model "three", from yard sale for $10..
The original woofers were replaced with two different models/mfg of woofers.
I know this is not good, so I want some advise as to choosing replacement woofers.
So I pulled them apart, they are two-ways with 10" woofer( 4-bolt pattern) and a 110mm tweeter. I can not find any information on these replacement woofers, one being a "Blaster" and the other a "ONPA"
I also figured out the cross-over, it is 1 pole for the woofer, I measure 1.62mH/0.23ohm, a small unit with a steel lamination. I know this is not very good either.
The tweeter ckt is 2-pole with 8uF in series with 2 ohms, followed by a 0.28mH/0.27 ohm, air wound coil to ground, then a 8 ohm L-pad to the tweeter.
So to start with I did a sim of the cross-over in ltspice, just to get an idea. I used the standard equivalent of a woofer as published in Bob Cordell's PA book.
For the tweeter I ordered a new tweeter from Madisound as Morel's were on special, so I bought two of MDT-32S. I have used Morel's in other speakers and I like this brand.
I used the 10KHz Z spec's for the Morel tweeter in the cross-over sim (90uH in series with 5.2 ohms)
I get a cross-over point around 1.8KHz, which seems to be fine for this setup, I think.
The box measures internally, 22.5"x11"x8.25" for 1.2 cu ft or 33.6L. The port is 2 3/8" W x 3 1/4" depth.
The BIG ? now, is, how do I go about replacing these woofers with something that matches the existing box?
I do not currently have any box design software. I guess I can get out the old Vance Dickerson LS design book and give it another read, figure out/measure, the existing woofer spec's and see how they would perform.
Any ideas, recommendations would be greatly appreciated.
Thanks
Rick
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Anyone? Seems to be easier to match the box to the speaker, than speaker to the box!!
ltspice .asc file loaded now
See
http://www.diyaudio.com/forums/soli...-lateral-mosfet-amplifier-14.html#post3697492
ltspice .asc file loaded now
See
http://www.diyaudio.com/forums/soli...-lateral-mosfet-amplifier-14.html#post3697492
Hi,
For $10 you could have replaced the bass drivers with
something cheap but the same and hoped for the best,
e.g. MCM Audio Select 10" Woofer with Poly Cone and Rubber Surround 100W RMS at 8ohm | 55-2972 (552972) | MCM Audio Select
tweaking the tweeter levels to suit.
However going for good tweeters first its much more
complicated and very silly, $80 a pop for each tweeter ?
10" hifi drivers are not built for 2 ways nowadays.
On paper the MCM driver is a good cheap replacement driver.
rgds, sreten.
For $10 you could have replaced the bass drivers with
something cheap but the same and hoped for the best,
e.g. MCM Audio Select 10" Woofer with Poly Cone and Rubber Surround 100W RMS at 8ohm | 55-2972 (552972) | MCM Audio Select
tweaking the tweeter levels to suit.
However going for good tweeters first its much more
complicated and very silly, $80 a pop for each tweeter ?
10" hifi drivers are not built for 2 ways nowadays.
On paper the MCM driver is a good cheap replacement driver.
rgds, sreten.
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Hi Stren,
I hear you about 10" woofers are not built for 2-ways these days, so I will try it out and hope for the best with the existing woofers.
It seems that many have big peaks past 1KHz, not sure why?
Thanks for the MCM link,
For $10 each almost crazy not to try and see what I can do with them.
I looked at Madisound and Parts-exprees, but did not look at MCM, even though I new about them from before.
I did see this and it might be one of my other options to use that Seas woofer A26RE4. Tuning the port will be my issue., to figure out, unless I seal it up completely or make some sort of aperiodic vent. I am re-reading my speaker design books now to see if I can figure the box calculation/measurement stuff. Might have to finally make the Mighty Mike.
The Madisound Speaker Store
I bought the Morel MDT32S thinking that it would be an okay replacement for the spec'd T-35 tweeters. So took a chance to try them out, if it does not work out, I can use them in a new design. Even if I make the A26 box as they have documented.
Oh well something to play around with this winter.
Thanks again
Rick
I hear you about 10" woofers are not built for 2-ways these days, so I will try it out and hope for the best with the existing woofers.
It seems that many have big peaks past 1KHz, not sure why?
Thanks for the MCM link,
For $10 each almost crazy not to try and see what I can do with them.
I looked at Madisound and Parts-exprees, but did not look at MCM, even though I new about them from before.
I did see this and it might be one of my other options to use that Seas woofer A26RE4. Tuning the port will be my issue., to figure out, unless I seal it up completely or make some sort of aperiodic vent. I am re-reading my speaker design books now to see if I can figure the box calculation/measurement stuff. Might have to finally make the Mighty Mike.
The Madisound Speaker Store
I bought the Morel MDT32S thinking that it would be an okay replacement for the spec'd T-35 tweeters. So took a chance to try them out, if it does not work out, I can use them in a new design. Even if I make the A26 box as they have documented.
Oh well something to play around with this winter.
Thanks again
Rick
Hi,
$80 a pop tweeters make sense in a $800 speaker kit.
FWIW the MCM drivers seem to be too good to be true,
on paper they are ideal replacements for many older
drivers at very low prices, though I will say there is
no reason why a modern cheap polypropylene driver
cannot be made to match older typical paper drivers.
Personally I'd try the cheap bass units with the
original tweeters, if it ain't bust don't fix it.
Two different cluelessly chosen woofers are just
a pointless exercise with expensive tweeters.
rgds, sreten.
FWIW I have an affection for genuinely good cone
tweeters before fashion eradicated them from
the market. Some of them are very good.
$80 a pop tweeters make sense in a $800 speaker kit.
FWIW the MCM drivers seem to be too good to be true,
on paper they are ideal replacements for many older
drivers at very low prices, though I will say there is
no reason why a modern cheap polypropylene driver
cannot be made to match older typical paper drivers.
Personally I'd try the cheap bass units with the
original tweeters, if it ain't bust don't fix it.
Two different cluelessly chosen woofers are just
a pointless exercise with expensive tweeters.
rgds, sreten.
FWIW I have an affection for genuinely good cone
tweeters before fashion eradicated them from
the market. Some of them are very good.
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I've done this a couple times. First, pick some vendors. I like Madisound, but also include Parts Express and MCM. Next, get some simple box design software like Boxplot or Unibox. Measure the internal volume of your box. Start entering driver parameters and running box designs until you find one similar in volume to your box, and with similar porting if a port is used. Purchase driver, install. Hopefully it's that easy, but it's amazing how many drivers are on the market that don't seem to have any practical application, not to mention commercial speakers with "unusual" drivers not duplicated by anything commonly available.
Hi,
Any consolation, I got the Morels on sale for $130 for the pair. The original tweeters did sound tinny, so that was another reason to try the Morel's out.
I have Morel MDM55 and MDT29 in another pair of speakers with a 15" bass woofer, mounted in a 3ft3 sealed unit an they are pretty good. Comparable to another pair of speakers that I have, Dynaudio Gemini's. More/low bass with the 15 woofers of course. The Gemini's are pretty precise even with a class D amp that I designed/built using a TI TPA3100D2.
When I put the 15" speakers with the Gemini's boy does it sound good. The Pioneer SX-950 manages to drive them okay, but I have changed the o/p's to use MJ15003/4. Don't think the older Toshiba bjt's would stand up for that load.
So you will think that I am a fool when I tell you I bought the Altec Lansing model 3 speakers for $10 at a garage sale 🙂 and am throwing more $ at them.
Thanks for your advise Sreten and Conrad
Cheers
Rick
Any consolation, I got the Morels on sale for $130 for the pair. The original tweeters did sound tinny, so that was another reason to try the Morel's out.
I have Morel MDM55 and MDT29 in another pair of speakers with a 15" bass woofer, mounted in a 3ft3 sealed unit an they are pretty good. Comparable to another pair of speakers that I have, Dynaudio Gemini's. More/low bass with the 15 woofers of course. The Gemini's are pretty precise even with a class D amp that I designed/built using a TI TPA3100D2.
When I put the 15" speakers with the Gemini's boy does it sound good. The Pioneer SX-950 manages to drive them okay, but I have changed the o/p's to use MJ15003/4. Don't think the older Toshiba bjt's would stand up for that load.
So you will think that I am a fool when I tell you I bought the Altec Lansing model 3 speakers for $10 at a garage sale 🙂 and am throwing more $ at them.
Thanks for your advise Sreten and Conrad
Cheers
Rick
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Hi,
The tweeters can sound poor due to the drivers fitted
or may indeed be simply poor, and I can't help you
ascertaining the reality from any assumptions.
I've no problem with chucking dollars at bargain good
speakers if you know what you are doing, but do have
a problem with changing the tweeters first on a pair of
speakers very likely to have simply very wrong bassmids.
YMMV and you can reuse the cabinets for the Seas kit.
However IMO for a $10 pair of speakers, with the original
x/o and tweeters, but naff bassmids, you can go the cheap
route with new bassmids, and use the original L-pads to
match tweeter levels to the new bassmid pair.
As its a 2 way some experimentation with the series
coil on the bassmid will make the most difference.
At that point you ascertain the tweeter quality needed,
i.e. based on the main driver, not assumptions.
Decent budget speakers seems a lot easier than
tying to turn $10 speakers into $1000 speakers.
rgds, sreten.
Expensive drivers + poor design = wasting money.
Cheap good drivers + good design = high value.
Its very hard work to make a good 10" two way,
a FAST with a FR instead of a tweeter is an idea.
The tweeters can sound poor due to the drivers fitted
or may indeed be simply poor, and I can't help you
ascertaining the reality from any assumptions.
I've no problem with chucking dollars at bargain good
speakers if you know what you are doing, but do have
a problem with changing the tweeters first on a pair of
speakers very likely to have simply very wrong bassmids.
YMMV and you can reuse the cabinets for the Seas kit.
However IMO for a $10 pair of speakers, with the original
x/o and tweeters, but naff bassmids, you can go the cheap
route with new bassmids, and use the original L-pads to
match tweeter levels to the new bassmid pair.
As its a 2 way some experimentation with the series
coil on the bassmid will make the most difference.
At that point you ascertain the tweeter quality needed,
i.e. based on the main driver, not assumptions.
Decent budget speakers seems a lot easier than
tying to turn $10 speakers into $1000 speakers.
rgds, sreten.
Expensive drivers + poor design = wasting money.
Cheap good drivers + good design = high value.
Its very hard work to make a good 10" two way,
a FAST with a FR instead of a tweeter is an idea.
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Yes Sreten, I hear you loud and clear,
but I do have a problem with changing the tweeters first on a pair of speakers very likely to have simply very wrong bass-mids.
So in retrospect, I should have asked for advise earlier/first before I bought the tweeters.
At this point, I am a self professed speaker hack, know how to waste $, so lets hope I can sort this out, so that it does not become a situation of
Expensive drivers + poor design = wasting money.
So I plan to sinking a little more $ & try the MCM woofers first, then proceed from their.
At least I'll have two woofers that match. Test/tune
Then if all all else fails, I have the option of
YMMV and you can reuse the cabinets for the Seas kit.
Thanks for your candid advise.
Rick
but I do have a problem with changing the tweeters first on a pair of speakers very likely to have simply very wrong bass-mids.
So in retrospect, I should have asked for advise earlier/first before I bought the tweeters.
At this point, I am a self professed speaker hack, know how to waste $, so lets hope I can sort this out, so that it does not become a situation of
Expensive drivers + poor design = wasting money.
So I plan to sinking a little more $ & try the MCM woofers first, then proceed from their.
At least I'll have two woofers that match. Test/tune
Then if all all else fails, I have the option of
YMMV and you can reuse the cabinets for the Seas kit.
Thanks for your candid advise.
Rick
Try them for 10$ .... but. (review)
Can't beat 10$ , I have these drivers as my lab test speakers (sacrificial).
In sealed boxes (55L) , poor bass !!! So , these are my "man cave" speakers.
They can handle all the power of a symasym, badger , or other amps ...
... but the sound quality is not even close to even the cheapest dayton driver.
The MCM 8" "small brother" to the 10" has the same weaknesses , they are now
in boxes , never to be heard by me again.
MCM audio select = garage speakers. 😀
Try the "big brother" to my 8" dayton's ... Dayton Audio DS270-8 10" Designer Series Woofer 295-432
Seal the box - 1.2cu. = F3 55hz.
OS
Can't beat 10$ , I have these drivers as my lab test speakers (sacrificial).
In sealed boxes (55L) , poor bass !!! So , these are my "man cave" speakers.
They can handle all the power of a symasym, badger , or other amps ...
... but the sound quality is not even close to even the cheapest dayton driver.
The MCM 8" "small brother" to the 10" has the same weaknesses , they are now
in boxes , never to be heard by me again.
MCM audio select = garage speakers. 😀
Try the "big brother" to my 8" dayton's ... Dayton Audio DS270-8 10" Designer Series Woofer 295-432
Seal the box - 1.2cu. = F3 55hz.
OS
Morel MDT32S remarks
I installed the Morel MDT32S, new L pads and vacuumed up the mouse pooh.
What an improvement over the old cone tweeters. Speakers came to life all of a sudden.
Now the woofers do not sound too bad, even if they are a different mfg. They are at least balanced, so that makes it better.
Since they are bass reflex, might be a bit of bass boom, certainly no amp bass boost is required.
Having an L pad for the tweeters, is so much better than what a treble control can do. Cheap bi-amp 🙂
Was reading an old Tab book "how to design,build & test complete speaker systems" by David B. Weems. I find it easier reading than Vance's book. The nostalgia of using a VTVM & a Eiko SG, it is a treat as well.
It would be fun to measure the woofers and test the box response to see what the measurements unfold. Time to make some speaker testing equip, mighty mike project and the other Dennis Colin phase SG?
Until next up date.
I installed the Morel MDT32S, new L pads and vacuumed up the mouse pooh.
What an improvement over the old cone tweeters. Speakers came to life all of a sudden.
Now the woofers do not sound too bad, even if they are a different mfg. They are at least balanced, so that makes it better.
Since they are bass reflex, might be a bit of bass boom, certainly no amp bass boost is required.
Having an L pad for the tweeters, is so much better than what a treble control can do. Cheap bi-amp 🙂
Was reading an old Tab book "how to design,build & test complete speaker systems" by David B. Weems. I find it easier reading than Vance's book. The nostalgia of using a VTVM & a Eiko SG, it is a treat as well.
It would be fun to measure the woofers and test the box response to see what the measurements unfold. Time to make some speaker testing equip, mighty mike project and the other Dennis Colin phase SG?
Until next up date.
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