Kram:
Good to hear from you again. Glad to see that you have not abandoned the project.
There are a lot of DIY projects that you see published that look good until you see that the author fully expects you to have all sorts of equipment on hand. He usually says something like, "You'll get much use out of this tool in future projects". With the cost of the tools necessary to complete the project, usually you could have gone into a store and bought whatever it was you planned on building! Grrr.
With the multimeter, though, it is both low-cost and I truly do think that you actually will get a lot of use out of it for various things.
Let me know when you obtain it and are ready to finish the project. 🙂
Good to hear from you again. Glad to see that you have not abandoned the project.
There are a lot of DIY projects that you see published that look good until you see that the author fully expects you to have all sorts of equipment on hand. He usually says something like, "You'll get much use out of this tool in future projects". With the cost of the tools necessary to complete the project, usually you could have gone into a store and bought whatever it was you planned on building! Grrr.
With the multimeter, though, it is both low-cost and I truly do think that you actually will get a lot of use out of it for various things.
Let me know when you obtain it and are ready to finish the project. 🙂
Hi,
i was not able to get the analogue meter i was after because the shop had ran out of them so i bought a cheaper digital one insted.
i conducted the 1st test to see if the amps output is flat and it is just about flat;
input Hz V out amp
1000 1.3
2000 1.3
3000 1.2
4000 1.2
5000 1.2
6000 1.3
7000 1.2
8000 1.2
9000 1.2
10000 1.1
11000 1.1
I have a little question about the meter, i had the meter set on ac 200 for the test and was just wondering what the actual voltage I measured was, is it 1.3V ? is that p-p or max amplitude or RMS?
anyway i will get the other test done as soon as i find another amp with a mic input.
thanks.
i was not able to get the analogue meter i was after because the shop had ran out of them so i bought a cheaper digital one insted.
i conducted the 1st test to see if the amps output is flat and it is just about flat;
input Hz V out amp
1000 1.3
2000 1.3
3000 1.2
4000 1.2
5000 1.2
6000 1.3
7000 1.2
8000 1.2
9000 1.2
10000 1.1
11000 1.1
I have a little question about the meter, i had the meter set on ac 200 for the test and was just wondering what the actual voltage I measured was, is it 1.3V ? is that p-p or max amplitude or RMS?
anyway i will get the other test done as soon as i find another amp with a mic input.
thanks.
From www.misterfixit.com: "Alternating current (AC) is what is delivered to you and is what runs everything in your home. The alternating part means that the voltage changes constantly from zero to plus 110 volts and then back to zero and then to minus 110 volts. This cycle repeats itself 60 times a second thus the description of your service is 110VAC 60Hz.
If you stick the leads of your meter into the house recepticle-or into an extension cord cord plugged into the wall-you will get a reading of approximately 110 volts. Well, you would in North America.
Therefore, when your meter reads 1 volt, it means the voltage you are measuring goes up (+1) volt and then goes down to (-1) volt.
Those readings you gave are flat enough-there is a 1.45 dB difference between 1.3V and 1.1V. Livable.
Incidentally, as long as you do have a digital meter, have you tried attaching the leads of the meter directly to jack of the micriphone? My meter seems to have a minimum reading of 5 mV or so, so it would be advisable for a microphone to be putting out 30 or 40 mV as a midpoint when you test the speaker.
Try speaking into microphone and seeing if you get it reasonably far above the minimum reading. If you can, you can forsake going through the sound card to the oscilloscope program and just take a reading.
I don't want to put too much power through those tweeters, especially. Not much more than a watt-which would be 3 volts or so input to the speaker.
But if you find that you can get a reading from your mic jack well above your meter's minimum with 3 volts output from the amp to the speaker, the test becomes simplified.
Good luck!
If you stick the leads of your meter into the house recepticle-or into an extension cord cord plugged into the wall-you will get a reading of approximately 110 volts. Well, you would in North America.
Therefore, when your meter reads 1 volt, it means the voltage you are measuring goes up (+1) volt and then goes down to (-1) volt.
Those readings you gave are flat enough-there is a 1.45 dB difference between 1.3V and 1.1V. Livable.
Incidentally, as long as you do have a digital meter, have you tried attaching the leads of the meter directly to jack of the micriphone? My meter seems to have a minimum reading of 5 mV or so, so it would be advisable for a microphone to be putting out 30 or 40 mV as a midpoint when you test the speaker.
Try speaking into microphone and seeing if you get it reasonably far above the minimum reading. If you can, you can forsake going through the sound card to the oscilloscope program and just take a reading.
I don't want to put too much power through those tweeters, especially. Not much more than a watt-which would be 3 volts or so input to the speaker.
But if you find that you can get a reading from your mic jack well above your meter's minimum with 3 volts output from the amp to the speaker, the test becomes simplified.
Good luck!
test mic
One posible reason for the big hump at 4k could be the mic used to do the test. For example a Sure SM57 has a hump at 4k . So does the SM58 (the hump adds "brilliance" to the vocal/inst.) Many clones of the '57 are around-- I have two '57 cloans. A graph of the responce of the mic can be found on the web. I have used test tones to check the responce of microphones, but have not measured the responce of my speakers🙂
One posible reason for the big hump at 4k could be the mic used to do the test. For example a Sure SM57 has a hump at 4k . So does the SM58 (the hump adds "brilliance" to the vocal/inst.) Many clones of the '57 are around-- I have two '57 cloans. A graph of the responce of the mic can be found on the web. I have used test tones to check the responce of microphones, but have not measured the responce of my speakers🙂
Hello there,
again sorry for the lack of activity since the last time I posted, I have been busy starting a years work placement as part of my degree.
I am affraid im going to have to give up the idea of trying to find the freq. responce of the tweeter I have as my dad wants the project finishing soon.
So i am going to buy two of these
http://www.audax.com/products/details/TM025F1.shtml from a local store (Maplins) unless of course anyone has any serious reservations about this tweeter (remember im on a budget) 🙁 .
Hopefully I will be able to start on crossover design and construction with peoples help and advice of course.😀
Thank you,
Kram🙂
again sorry for the lack of activity since the last time I posted, I have been busy starting a years work placement as part of my degree.
I am affraid im going to have to give up the idea of trying to find the freq. responce of the tweeter I have as my dad wants the project finishing soon.
So i am going to buy two of these
http://www.audax.com/products/details/TM025F1.shtml from a local store (Maplins) unless of course anyone has any serious reservations about this tweeter (remember im on a budget) 🙁 .
Hopefully I will be able to start on crossover design and construction with peoples help and advice of course.😀
Thank you,
Kram🙂
No serious reservations about those tweeters at all, Kram, except I think the faceplate is square while the cutout is round. Merely cosmetic.
I will be glad to help you design a crossover, but first I want to do a quick search to see if anyone om the web has a project that uses that woofer and tweeter.
Why guess when someone has already worked it out?
By the way, anyone want to jump in here and come up with crossover suggestions, please do.
Back to you soon.
I will be glad to help you design a crossover, but first I want to do a quick search to see if anyone om the web has a project that uses that woofer and tweeter.
Why guess when someone has already worked it out?
By the way, anyone want to jump in here and come up with crossover suggestions, please do.
Back to you soon.
Oops, the Audax tweeter does have a round faceplate. So it should in or around the cutout for the AR tweeter. Good.
I have read this thread with interest because I am also looking at repairing my Accoustic Research AR18LS speakers which I bought about 23 years ago. Cost me £110 then.
The problem I have is the foam surround on the main 8" drivers is starting to perish and is ripped in a few places and on one of the speakers a large chunk is missing.
I understand that I can repair the rubber with a repair kit. Is this really viable? My concern is that the speakers may deteriorate in other ways.
However, my thoughts were initially that I should replace the 8" speakers in each cabinet with a new replacement and the Audax ones (Audax AP210Z0) mentioned in this thread are available at my local Maplin store in the UK for £26 each. I would be very interested to hear how Kram's project turned out. Are you there Kram? I see there being risk in this approach as I may end up having to get new crossovers and new tweeters
However, I can also buy a new pair of speakers at www.RicherSounds.co.uk - e.g. Mission 700's for only £50, and I can't help thinking that it would be more economic to do so and I suspect that a modern ported design would sound better. The AR18LS were pretty good bookshelf speakers in their time but that was about 25 years ago.
Has anyone got any advise or experience on this? How does a modern bookshelf speaker of today compare with one 25 years ago?
The problem I have is the foam surround on the main 8" drivers is starting to perish and is ripped in a few places and on one of the speakers a large chunk is missing.
I understand that I can repair the rubber with a repair kit. Is this really viable? My concern is that the speakers may deteriorate in other ways.
However, my thoughts were initially that I should replace the 8" speakers in each cabinet with a new replacement and the Audax ones (Audax AP210Z0) mentioned in this thread are available at my local Maplin store in the UK for £26 each. I would be very interested to hear how Kram's project turned out. Are you there Kram? I see there being risk in this approach as I may end up having to get new crossovers and new tweeters
However, I can also buy a new pair of speakers at www.RicherSounds.co.uk - e.g. Mission 700's for only £50, and I can't help thinking that it would be more economic to do so and I suspect that a modern ported design would sound better. The AR18LS were pretty good bookshelf speakers in their time but that was about 25 years ago.
Has anyone got any advise or experience on this? How does a modern bookshelf speaker of today compare with one 25 years ago?
Hi Gary,
I am still here and within a few weeks i will be getting ready to start finishing this project, all i need to do is buy those tweeters i mentioned earlier and get a xover built, its only taken me 5 months to get this far.😉
I have never seen one of those repair kits before so i dont know if they are worth it or how easy they are to use. I still have the AR drivers and it is also the foam bits that have completely disintegrated. I will probably fix them one day too. I also believe that you could get the drivers fixed for you by a shop, i saw one online ages ago, im sorry but i couldnt find it again.
When i tried to fit the new Audax drivers into the AR box i discoverd that they were slightly too wide so i had to use a router to make the existing cut outs a little larger. you may also have to do this and you will probably also have to buy new tweeters and xovers as you said.
If i had the chance i would probably not do what i did but have the audax drivers refurbished instead, either DIY or by a shop.
here is a website that has an AR forum, maybe someone on there knows where to get drivers refoamed.
http://www.arsenal.net/cgi-bin/dcforum/dcboard.cgi
I hope i was some help.
Kram
🙂
I am still here and within a few weeks i will be getting ready to start finishing this project, all i need to do is buy those tweeters i mentioned earlier and get a xover built, its only taken me 5 months to get this far.😉
I have never seen one of those repair kits before so i dont know if they are worth it or how easy they are to use. I still have the AR drivers and it is also the foam bits that have completely disintegrated. I will probably fix them one day too. I also believe that you could get the drivers fixed for you by a shop, i saw one online ages ago, im sorry but i couldnt find it again.
When i tried to fit the new Audax drivers into the AR box i discoverd that they were slightly too wide so i had to use a router to make the existing cut outs a little larger. you may also have to do this and you will probably also have to buy new tweeters and xovers as you said.
If i had the chance i would probably not do what i did but have the audax drivers refurbished instead, either DIY or by a shop.
here is a website that has an AR forum, maybe someone on there knows where to get drivers refoamed.
http://www.arsenal.net/cgi-bin/dcforum/dcboard.cgi
I hope i was some help.
Kram
🙂
Hi,
I found 2 websites that offer speaker restoration and refoaming
http://www.loudspeakers-online.com/index.htm
and
http://www.wembleyloudspeaker.com/
I think you will have to e-mail/phone them for a quote as neither shop say how much refoaming costs on their websites.
This place gives a price of $45 a pair so i think it will be kind of similar in pounds (then again we live in rip off britain) 🙁
http://layneaudio.hypermart.net/repair.htm
i also saw your post on the AR websits msg board. it seems that quite a few peoples AR18BX spakers are falling appart at the same time.😱
Kram out.
I found 2 websites that offer speaker restoration and refoaming
http://www.loudspeakers-online.com/index.htm
and
http://www.wembleyloudspeaker.com/
I think you will have to e-mail/phone them for a quote as neither shop say how much refoaming costs on their websites.
This place gives a price of $45 a pair so i think it will be kind of similar in pounds (then again we live in rip off britain) 🙁
http://layneaudio.hypermart.net/repair.htm
i also saw your post on the AR websits msg board. it seems that quite a few peoples AR18BX spakers are falling appart at the same time.😱
Kram out.
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