Tweeters or Capacitors First?

jcandy

I forgot to add that, for the purpose of monitor-series crossover upgrades, you can safely stick with any good metallized polypropylene unit (lately I have been using Erse from Meniscus Audio -- AFAIK Erse is made in USA). It is also handy to buy inductors from Meniscus because they will unwind to a custom value.

TennMan

Candy that is a lot for someone new like me to absorb. However I can see the lines plotted on the graph for the sl2000 and RDO are very close throughout most of the frequency range. I really doubt that my ears could tell the difference but I'm not sure the graph tells the whole story of how the tweeters will sound in a normal listening environment. I'm just not smart enough on this subject to know one way or the other. I will say that I intend to ease into making changes a little at a time. I like the way the 10s sound right now but would like to do what I can to make them better but I also want to keep sight of a clear path back to where I am now if I make a mistake by changing something that results in a sound that I'm not happy with.

As suggested by a lot of other people here, my first step will be to make changes that will insure everything is up to factory specs or better and go from there. That will include new crossover electronics and making sure the drivers are sealed in the cabinets as they should be so I'm getting the sound that they had when they were new. After that making a decision on the tweeters to me would be the next logical step. I'm listening to everything you guys have to say. It's a learning experience for me and I'm really enjoying it. :biggrin:

I really appreciate everyone's comments. It's great to be here in this forum with all this knowledge available and be able to get differing opinions.

ben62670

Ignore his measurements. They tell nothing of sound quality. Many speakers can reproduce nearly identical frequency response, but yet sound totally different from each other. Looking at specs most modern gear would sound the same on paper.

chandler9a

Hey Tenn, I think you are taking the right steps toward this process... enjoying the sound you like. I grew up on the SL-2000 tweater since my father bought SDA's when I was a young boy. I eventually bought my own pair of SDA's and began the journey of tweaks found on this forum.

I will admit that they never really bothered me until I started doing some critical listening and found that the highs bothered me at times. I saved up and put some RDO 194s in my speakers and can tell you it was worth every penny. My father has done the same.

I got my Monitor 10's the same time you did and am keeping the 2000's in for now which is fine, they sound good. However, they will eventually get all the treatments and I cant wait too hear them evolve.

Keep on enjoying what you have and when you do make the upgrades, keep us posted on your impressions of them.

Aaron

P.S. Ditto on what Ben said above

TennMan

Thanks for the encouragement.

I really may not even know the true sound of what two good sl2000s sound like this point. When I got my 10s one of the tweeters was bad (see photo). I soldered the broken wire and it started working but I'm sure it isn't 100% of what it should be because of the hole in the dome. The person I got the speakers from promised to replace the tweeter but it must have been put on a mule train that is headed this way. Once I get the replacement and install it I might hear something different than I'm hearing now. Better (I hope) or worse I don't know. Either way I'm having fun getting to know the 10s.

jcandy

ben62670 wrote: »

Ignore his measurements. They tell nothing of sound quality. Many speakers can reproduce nearly identical frequency response, but yet sound totally different from each other. Looking at specs most modern gear would sound the same on paper.

Interesting. Please give me an example of two speakers with the same SPL that sound totally different (please including the SPL curves) :rolleyes: Oh, and make sure the speakers have the same baffle and crossover ... I am laughing so hard now I can barely type!

On the contrary, I have various sets of completely different speakers, with different drivers, and the ones with flat SPL all sound quite similar (above the point where the bass-extension drops off). Usually, the tonal difference between speakers shows up right away in the SPL (for example, my Paradigms have a sound which is characteristic the downward-sloped SPL). The difference between systems with similar on-axis SPLs is, of course, related to power response (which is a strong function of baffle size) and distortion. At higher listening levels, thermal effects will also occur. Since we are in a situation (SL2K versus RD0-194) where power response, THD and thermal handling must be very close, there's not much else at work here (except imagination). At this point, the only plausible explanation seems to be that older SL2K are inferior to more recent ones.

ben62670

I'm glad I made you laugh. I used to think like you. Now I know better. I am not laughing at you. I just feel bad for you.
Ben

jcandy

TennMan wrote: »

I really may not even know the true sound of what two good sl2000s sound like this point.

The RDO question is a moot point now. You need to replace tweeters. In general, dents in the dome affect the high-frequency response while perforations in the dome affect the medium-frequency response (which is worse).

F1nut

Change the tweeters and upgrade the crossovers at the same time. Don't dick around with those nasty +5dB @ 13kHz SL2000's any longer than you have to.

jcandy

ben62670 wrote: »

I'm glad I made you laugh. I used to think like you. Now I know better. I am not laughing at you. I just feel bad for you.

Oh, come on. I seriously doubt you feel bad for me, as if you are some sort of missionary, and its almost inconceivable that you "used" to think like me. Why don't you just do both of us a favour and offer your own opinion whilst ignoring my posts. I do my best to ignore the blatant hooey that the resident "audiophiles" here dish out.

jcandy

F1nut wrote: »

Change the tweeters and upgrade the crossovers at the same time. Don't dick around with those nasty +5dB @ 13kHz SL2000's any longer than you have to.

Just to be clear, my measurements do in fact show that the SL2000 is up +5db at 13kHz vs 8kHz. I believe this is consistent with the criticism on the SL2000. However, the RDO-194 has an equally severe peak, just moved up slightly to about 13.5kHz. Are you taking about an upgrade to RDO-198?

TennMan

jcandy wrote: »

At this point, the only plausible explanation seems to be that older SL2K are inferior to more recent ones.

Is it possible to look at the date stamp on the back of the tweeter to determine which group of sl2000s a speaker has? Have you been able to test enough to narrow down the date a change in the sl2000 was made? It would be helpful to know that date. Maybe a new thread is in order where the date on the tweeter can be listed along with the owners impression of how they sound. Who knows? Maybe a pattern would form.

I enjoy hearing from both sides of this issue.

ben62670

All SL2000's were made the same. The comment about the tweeters being older has more to do with the plastic/poly domes aging. The older the tweeter the more they degrade. Fabric domes don't suffer sound degradation like their plastic counterparts. Jcandy obviously has little practical experience with audio. According to him all speakers sound the same if they put out the same frequencies. I guess he has never heard the difference between poly, metal, and fabric domed tweeters. Never mind the distinct sound a horn puts out. Just as an example a violin is made of different kinds of wood, or even the same kind of wood, or even wood from the same tree, but is cut near or far from the stump. Even if the violin is tuned the same and plays the notes at the same SPL it sounds different than another violin made from a different piece of material.

jcandy

TennMan wrote: »

Is it possible to look at the date stamp on the back of the tweeter to determine which group of sl2000s a speaker has? Have you been able to test enough to narrow down the date a change in the sl2000 was made? It would be helpful to know that date. Maybe a new thread is in order where the date on the tweeter can be listed along with the owners impression of how they sound. Who knows? Maybe a pattern would form.

I enjoy hearing from both sides of this issue.

These are good suggestions, although the "owners impression" could be problematic because of a significant subjective bias. I have only a single pair of the SL2000 (labeled "SL2000T" on the box, "SL2000" on the driver, and date stamped 1994). They are replacements. The RDO-194 were purchased last September. As I said before, there must be a Polk engineer about who can easily clear this up. There have been threads about this, but none I can find really answer the basic question. There were suggestions that the SL2000T was "the same" as the RDO-194, and other fairly obvious counter-claims (since the RDO-194 is a fabric dome, it can't be the same as the SL2000T, which is a mylar dome).

One thing is for sure: the SL2000T sounds almost identical on-axis to the RDO-194. Anyhow, because you have a perforated dome, you will want to replace your existing units.

TennMan

I guess it boils down to how each person's ears perceive the sound produced by a pair of speakers in their own particular listening environment. There are so many other variables involved in how we actually hear the sounds produced by a given pair of speakers besides just the flat frequency response plotted on a graph under controlled conditions. The graph might prove that the RDO is a better tweeter on paper but doesn't prove that it is the best choice for my listening experience. The acoustics of the room, the ability of the listener to hear all the frequencies produced by the speaker and what sound the listener likes or dislikes all play a part in how well we enjoy what we are hearing from the speakers. I think the tweeter plays a important part in the sound we hear but it must mesh with all the other variables for us to get the WOW factor that we are all looking for. As an example I have a slight hearing loss in the higher frequencies. So if there is a bump in the high frequency range it could explain why I don't find the sl2000 harsh. Another person might sit down to listen to my speakers and wonder how I put up with what they hear.

When it comes time to make a decision on the RDOs I will have to purchase a pair to find out if they are for me or not, (unless someone is willing to loan a pair and I don't think that is likely). Then I can compare them to the sl2000 myself and make a decision based on what I can hear. That is the only way I will know for sure they are for me. Listening to speakers with RDOs installed at someone else's house would not be a good test because of the other variables mentioned above would not be consistent with my house.

Thanks to you all for your input!

jcandy

ben62670 wrote: »

Jcandy obviously has little practical experience with audio.

Obviously. He requires objective measures of performance, and can design and build a loudspeaker from scratch, so he can't be a true audiophile.

ben62670 wrote: »

According to him all speakers sound the same if they put out the same frequencies.

I don't actually have any idea what you are trying to say, here. What on earth does it mean, exactly, for two loudspeakers to "put out the same frequencies"?

jcandy

TennMan wrote: »

I guess it boils down to how each person's ears perceive the sound produced by a pair of speakers in their own particular listening environment.

Well, as your ears age, they progressively lose the ability to hear high frequencies. My daughter can totally hear stuff in the 18kHz range that I simply cannot.

TennMan wrote: »

There are so many other variables involved in how we actually hear the sounds produced by a given pair of speakers besides just the flat frequency response plotted on a graph under controlled conditions.

Definitely. But the flip-side is that you cannot escape anomalies in the on-axis SPL. If you have a severe bump or trough in the SPL, the speaker will generally sound awful.

TennMan wrote: »

The graph might prove that the RDO is a better tweeter on paper but doesn't prove that it is the best choice for my listening experience.

Actually, I don't think the graph proves superiority of either the RDO or SL. They are so similar that it is almost certainly a matter of listener preference, room, etc.

TennMan wrote: »

The acoustics of the room, the ability of the listener to hear all the frequencies produced by the speaker and what sound the listener likes or dislikes all play a part in how well we enjoy what we are hearing from the speakers.

The room is indeed very important. In an active room, you will want to attenuate the tweeter level accordingly. There is also the matter of power response (directivity) of the speaker, which determines how the speaker interacts with reflecting surfaces.

TennMan wrote: »

I think the tweeter plays a important part in the sound we hear but it must mesh with all the other variables for us to get the WOW factor that we are all looking for. As an example I have a slight hearing loss in the higher frequencies. So if there is a bump in the high frequency range it could explain why I don't find the sl2000 harsh. Another person might sit down to listen to my speakers and wonder how I put up with what they hear.

Agreed. I am designing a system with a friend who wears a hearing aid. The tweeter is not a huge concern of his

TennMan wrote: »

When it comes time to make a decision on the RDOs I will have to purchase a pair to find out if they are for me or not, (unless someone is willing to loan a pair and I don't think that is likely). Then I can compare them to the sl2000 myself and make a decision based on what I can hear. That is the only way I will know for sure they are for me. Listening to speakers with RDOs installed at someone else's house would not be a good test because of the other variables mentioned above would not be consistent with my house.

This is a perfectly sensible approach. Yet, I think at this point, I'd be motivated by other concerns. You have a pair of vintage speakers which are, on one hand, great performers by sub-$1000 standards. On the other hand, there are fundamental issues with the design and you're never going to cure them with tweaks (like upgraded caps and tweeters). These will never be "superb" speakers. I would restore them to their original spec (which would mean finding a pair of replacement SL2000) and take pride in their authenticity. If its true performance you are after, there are some DIY projects that will blow the monitor 10 out of the water in terms of fidelity.

TennMan

Candy I think we are in agreement on most points. I know the 10s aren't the best speakers out there but they do a good job at a low cost and that is what I was looking for. I started looking for a pair of 10s based on hearing a pair of monitor 7s that a friend of mine owned years ago. I was hoping the 10s would be as good or better than the way I remembered the 7s sounding and I haven't been disappointed.

I've never heard the "superb" speakers and it might be a good thing. If I knew what superb speakers sounded like and couldn't afford them then I probably would never be happy with what I have. So far the 10s meet my needs and I'm happy with them and I hope it stays that way.

Just wonder... what do you consider superb speakers? Are there any cheap ones?

jcandy

TennMan wrote: »

Candy I think we are in agreement on most points. I know the 10s aren't the best speakers out there but they do a good job at a low cost and that is what I was looking for. I started looking for a pair of 10s based on hearing a pair of monitor 7s that a friend of mine owned years ago. I was hoping the 10s would be as good or better than the way I remembered the 7s sounding and I haven't been disappointed.

Don't get me wrong, a pair of 10s in working order is an excellent setup that anyone could be happy with.

TennMan wrote: »

Just wonder... what do you consider superb speakers? Are there any cheap ones?

The Orion and Pluto are very well-respected, although I have not heard them.

http://www.linkwitzlab.com/

Dan Neubecker has some extremely impressive projects if your woodworking skills are up to the task; the HOSS for example was the highest scoring speaker at DaytonDIY2008:

http://www.parts-express.com/projectshowcase/indexn.cfm?project=hoss

Zaph has all sorts of interesting and relatively cheap designs; in particular a series based on his own ZA14W08 woofer and the $13 Vifa DQ25 tweeter (these will still require a sub for the lowest octave):

http://www.zaphaudio.com/ZA5/

However, this utter monstrosity won't:

http://www.zaphaudio.com/SB12.3/

Some more expensive DIY examples from Denmark:

http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm

and finally, from the Netherlands:

http://www.humblehomemadehifi.com/

FTGV

jcandy wrote: »

Zaph has all sorts of interesting and relatively cheap designs; in particular a series based on his own ZA14W08 woofer and the $13 Vifa DQ25 tweeter (these will still require a sub for the lowest octave):

Yep I really like my ZA5.2''s I'm using for desk top monitors.

FTGV

jcandy wrote: »

Obviously. He requires objective measures of performance, and can design and build a loudspeaker from scratch, so he can't be a true audiophile.

Nah that won't cut it,you need to engineer your own drivers aswell.

jcandy

FTGV wrote: »

Nah that won't cut it,you need to engineer your own drivers aswell.

Someday :frown:

The odd thing about the ZA14W08 is that its awfully similar to the MCM 55-3870. I wonder what sort of deal was struck with MCM to allow a semi-clone of that driver?

TennMan

Dan Neubecker has some extremely impressive projects if your woodworking skills are up to the task; the HOSS for example was the highest scoring speaker at DaytonDIY2008:

I like the looks of those things!!! When I was a kid I always wanted a robot. A robot that could sing would be even better. :biggrin:

heiney9

TennMan wrote: »

I guess it boils down to how each person's ears perceive the sound produced by a pair of speakers in their own particular listening environment. There are so many other variables involved in how we actually hear the sounds produced by a given pair of speakers besides just the flat frequency response plotted on a graph under controlled conditions. The graph might prove that the RDO is a better tweeter on paper but doesn't prove that it is the best choice for my listening experience. The acoustics of the room, the ability of the listener to hear all the frequencies produced by the speaker and what sound the listener likes or dislikes all play a part in how well we enjoy what we are hearing from the speakers. I think the tweeter plays a important part in the sound we hear but it must mesh with all the other variables for us to get the WOW factor that we are all looking for. As an example I have a slight hearing loss in the higher frequencies. So if there is a bump in the high frequency range it could explain why I don't find the sl2000 harsh. Another person might sit down to listen to my speakers and wonder how I put up with what they hear.

When it comes time to make a decision on the RDOs I will have to purchase a pair to find out if they are for me or not, (unless someone is willing to loan a pair and I don't think that is likely). Then I can compare them to the sl2000 myself and make a decision based on what I can hear. That is the only way I will know for sure they are for me. Listening to speakers with RDOs installed at someone else's house would not be a good test because of the other variables mentioned above would not be consistent with my house.

Thanks to you all for your input!

Trust those of us who have been around Polk speakers and this tweeter especially. I was as skeptical as anyone and the RD0's are so much better than the sl2000 tweeter in every aspect.

That's all I can say and I can tell you I have alteast 20 years listening, selling, owning classic Polk speakers. I replace with RD0's without question.

If you decide not to do it or try it you are missing out, especially since atleast one of your tweeters looks heavily damaged.

H9

FTGV

jcandy wrote: »

Someday :frown:

The odd thing about the ZA14W08 is that its awfully similar to the MCM 55-3870. I wonder what sort of deal was struck with MCM to allow a semi-clone of that driver?

Just speculation on my part but maybe John liked the 3870 so much that he went directly to the Asian supplier with some ideas for improving it.(ie.phase plug,shorting rings.)Having used both they are visually identical apart from the phase plug in the ZA14.The changes and the doubling of the asking price might differentiate it enough to keep MCM's lawyers off his back.:biggrin:

jcandy

TennMan wrote: »

I like the looks of those things!!! When I was a kid I always wanted a robot. A robot that could sing would be even better. :biggrin:

Dan just amazes me. He has numerous unique designs. You can see more of them at:

http://techtalk.parts-express.com/showthread.php?t=216510

jcandy

FTGV wrote: »

Just speculation on my part but maybe John liked the 3870 so much that he went directly to the Asian supplier with some ideas for improving it.(ie.phase plug,shorting rings.)Having used both they are visually identical apart from the phase plug in the ZA14.The changes and the doubling of the asking price might differentiate it enough to keep MCM's lawyers off his back.:biggrin:

Right. I'm sure it must be something like this.

I have numerous 3870s (4-6, I'm not sure) sitting in the garage just waiting for an application. Great speaker choice for a first DIY project. On the other hand, most all the "sweet" MCM speakers (3870, 3853, 1853) are on backorder now and have been for months. I've been wanting to build a pair of ZBM4 (even got a 35mm Forstner bit for this purpose) but the 1853 is not available.

FTGV

I have an idle pair of 3870's so I'm either going to build a pair of ZMV5's or if I get real ambitious use them in a little active 3 piece sub-sat system.

Oldfatdogs

Tennman I have been watching your post very carefully.I am going to do my 7bs soon.This has been a very helpful post for me .I have found many of the older posts to be very useful also.The pictures in the monitor 5 rebuild have been great.Let us know how the big hands little parts thing goes. I'm in the same boat on that one.Good luck to you!

TennMan

Oldfatdogs wrote: »

Tennman I have been watching your post very carefully.I am going to do my 7bs soon.This has been a very helpful post for me .I have found many of the older posts to be very useful also.The pictures in the monitor 5 rebuild have been great.Let us know how the big hands little parts thing goes. I'm in the same boat on that one.Good luck to you!

I have been reading the older posts myself. I will certainly let everyone know how it goes when I do it. I intend to take photos as well and post them here.