Kirby meets Toid Speaker Build and Dsign

[[email protected]]

Scott, that really was a prime example of me not being able to tell. I only had 3 minutes, and the source material was suspect. I'm just not sure I can give you an honest answer either way here.

Later,
Wolf

To be fair, you're right, the amount of time you got to listen was limited. But I would expect a room full of people to be able to pick issues like that out. The only issues anyone I've talked to noticed was the tweeter, as they should have.

We'll see how much that changes with my modifications to the crossover. Going to be changing out a couple parts to try to alleviate the issue with the tweeter. The woofer is staying that 1st order. I'm not messing that flat midrange up :P

[Paul K.]

I've always said, "make the crossover as complex as necessary and as simple as possible", to the generous DIY friends that have designed them for me.
Paul

I was in a bit of a mood for some reason, and I could have toned it down a notch. However, some things just push my buttons sometimes. Lately it's the notion that the fewer x-over parts, the better. I simply don't agree with that theory. If others do, that's OK, but I don't like to see someone get talked into accepting that theory. Less parts is less work to assemble though, so if it's simply trying to make the build easy, I guess that's one of the design trade offs. I just don't think a low part count should be the goal.

I did get confused watching the video, because I saw the impedance graph was for the 4 ohm. In checking the 8 ohm data sheet, I saw that PE says 50hz f3. I didn't sim it. Maybe that's wrong. I did not sim the 4 ohm either, and I wonder if it actually can go that low.

I did play with the files in PCD, and I think a better x-over could be made. It would cost more, but I think it's worth it.. The speaker may sound great as designed. I shouldn't have said that I'd find it fatiguing. I'm sure I've built some with the same breakup issues.

[dld]

To be fair, you're right, the amount of time you got to listen was limited. But I would expect a room full of people to be able to pick issues like that out. The only issues anyone I've talked to noticed was the tweeter, as they should have.

We'll see how much that changes with my modifications to the crossover. Going to be changing out a couple parts to try to alleviate the issue with the tweeter. The woofer is staying that 1st order. I'm not messing that flat midrange up :P

I don't put a lot of weight to the valuations at shows, a room full of people may identify glaring issues but thats about it. I have had speakers that I thought were pretty good for a while and then they start to grate on you or you find some recordings that reveal some flaw. This does happen somewhat less now that everyone has measurement capabilities and simulation software, but there is no substitute for long term listening in your own room with your favorite recordings.

[Jake]

rpb: much better approach. The OP simply stated he was inspired by another build using only a 5 part crossover. Let's not assume he thinks that's the best method for every build. I'm sure he would be happy to hear any suggestions you could give.

[Altoid]

Wow, thank you everyone who responded. I had no idea anyone responded. I guess next time, I should subscribe to get all emails to my own thread "Doh." There are some great points and tips. I will say the cone breakup did not show in the harmonic distortion graphs, however there was a little in the waterfall. Having said that, I still haven't heard it yet. I'm sure it could be taken care of easily and I may work further on the crossover, as I get time. I'll also have a matching center to go along with this at some later time. So I may do some work on them both at the same time. I'll use the same tweeter and probably 2 RST125-4's to make an MTM.

Sorry, I was on a deadline to get the video out and I somehow clicked on the wrong driver when taking a screenshot. I did pin a note in the comments section of the video. Somehow I missed it in editing. Sorry if I confused anyone. It is the 8ohm shielded woofer. Which is the same woofer that Paul Carmody used in his Amiga build. I actually did not realize that when I started this build. It wasn't until much later, so I actually took his box design. The only difference, I used two 2" ports instead of one. And I used 3 window braces instead of 2 with side braces. That woofer can go much lower than PE recommends, it just needs a bigger box.

As far as the tweeter goes. I really like the RST28F-4. It is a really nice tweeter. At least I am happy with the performance of it. I will definitely be using it more builds.

I'm sure I missed like a million other questions people had.

[Altoid]

Hey Nick,

Watched both your and Kirby's videos last night. They look pretty fantastic, I must say. Glad I could be an inspiration, but Wolf has to take some credit for it. He forced my hand, after all. ;)

Seriously though, I bet they sound quite good. I'm curious as to your thoughts of the RST28. I'm looking at possibly using them for my towers I want to build next year.

Cheers!

Well thank you both [email protected] and Wolf for the inspiration. Scott I really like the RST28F-4. I have not used the Aluminum ones, so I can't speak to them. But so far in this build they are fun little speaker. I will say, which I know is going to get me into a lot of trouble on this site, but I typically design speakers more for theater use. And for that I really like them. But seriously, this pairing has been really nice to me. It helps fill the room really well. I was watching the movie 9, well just the beginning. But man, it really filled the room with sound and the bass actually shook the wall behind us. Granted, this is a small living room, and I had it up fairly loud, so take that into account. But I thought they paired nicely. And the tweeters have not at all hurt my ears. Which I appreciate. And they have very low distortion, which is a huge plus for me. So overall, I have enjoyed them.

[Wolf]

I've always said, "make the crossover as complex as necessary and as simple as possible", to the generous DIY friends that have designed them for me.
Paul

Mine is quite similar:
"As simple as possible with respect to necessity." (unless you are experimenting!)

Later,
Wolf

[rpb]

Mine is quite similar:
"As simple as possible with respect to necessity." (unless you are experimenting!)

Later,
Wolf

Almost all my speakers are temporary experiments, and the x-overs are external, and connected with jumpers. It's not uncommon for me to use 12 parts in a 2-way, but I have used less than 9 frequently. I had a 3-way that was around 30. There was no way I was going to actually solder up that x-over to make a permanent speaker. Soon, I will finish a pair of small 2-ways, just to have one pair that is complete.

[rpb]

Wow, thank you everyone who responded. I had no idea anyone responded. I guess next time, I should subscribe to get all emails to my own thread "Doh." There are some great points and tips. I will say the cone breakup did not show in the harmonic distortion graphs, however there was a little in the waterfall. Having said that, I still haven't heard it yet. I'm sure it could be taken care of easily and I may work further on the crossover, as I get time. I'll also have a matching center to go along with this at some later time. So I may do some work on them both at the same time. I'll use the same tweeter and probably 2 RST125-4's to make an MTM.

Sorry, I was on a deadline to get the video out and I somehow clicked on the wrong driver when taking a screenshot. I did pin a note in the comments section of the video. Somehow I missed it in editing. Sorry if I confused anyone. It is the 8ohm shielded woofer. Which is the same woofer that Paul Carmody used in his Amiga build. I actually did not realize that when I started this build. It wasn't until much later, so I actually took his box design. The only difference, I used two 2" ports instead of one. And I used 3 window braces instead of 2 with side braces. That woofer can go much lower than PE recommends, it just needs a bigger box.

As far as the tweeter goes. I really like the RST28F-4. It is a really nice tweeter. At least I am happy with the performance of it. I will definitely be using it more builds.

I'm sure I missed like a million other questions people had.

The woofer does model very well in bigger boxes! The PE info is misleading.

[rpb]

TBH, rpb, I was surprised it was selected due to the criteria. I did not see that one coming out on top. However, as many that I know are committing, there will be plenty of entries. I'm going to try it too. The challenge is to succeed, but I don't think it's a joke, nor unattainable.
I am also skeptical about this project since it does not seem to have any breakup compensation, but without more information, I am only guessing.

Nigel, a heat bridge is of course the norm, which is why you tin the iron first, but I did not see him move the iron or feed from across the joint. You'd be surprised how many people on this forum have thought soldering is and I quote: "painted on" or 'applied to the iron' and not the joint. This was just a clarity point, as it did not appear to be what he was doing. Cold solder joints are not ever a good idea for reliability, and if you don't thoroughly heat the joint, the bond will be inferior, it will have reduced contact with higher resistance, and also be prone to failure with age. I just want the best results for everyone, plain and simple.

Later,
Wolf

I wonder how many of the people planning to enter will change their mind when they start playing with sims, or hear their design? I attempted to make a 5 part x-over for drivers that I've been using for a while. I'm very familiar with how they sound with a lot of different x-overs. I thought they were just about ideal for the contest. I was able to make a 5 part x-over, and the response was smooth. The speaker did not sound good to me though. I could look at the measurements, and see why, but without at least one more part, I couldn't improve it. That one part might be a $6 cap, or a $2 resistor. The point is, that speaker would be seriously compromised to save less than $10/speaker. I know that part of your goal with these contests is to use drivers that are available, so that someone else can build the design. Lets say you win this contest, but know that with one more resistor, and cap, it's a much better design. Would you want anyone building the 5 part version, and calling it your design?

[Wolf]

It depends on the outcome, but I Ihaven't won any of my own themes, and I also don't vote. If I felt it was warranted, I would post my impressions about being unsatisfied with the results, and publish the original as heard, and an improved version. The thing about this challenge is that it can display upgrade improvement paths readily. I have heard 5part systems sound great, top of my head is Chuck's Misfits, and it would fit the criteria.

Later,
Wolf

[Billet]

I am a fan of minimal crossovers, so I applaud your design goals and efforts. The sound is what matters, if you like the sound then all is good.

[DanP]

I wonder how many of the people planning to enter will change their mind when they start playing with sims, or hear their design? I attempted to make a 5 part x-over for drivers that I've been using for a while. I'm very familiar with how they sound with a lot of different x-overs. I thought they were just about ideal for the contest. I was able to make a 5 part x-over, and the response was smooth. The speaker did not sound good to me though. I could look at the measurements, and see why, but without at least one more part, I couldn't improve it. That one part might be a $6 cap, or a $2 resistor. The point is, that speaker would be seriously compromised to save less than $10/speaker. I know that part of your goal with these contests is to use drivers that are available, so that someone else can build the design. Lets say you win this contest, but know that with one more resistor, and cap, it's a much better design. Would you want anyone building the 5 part version, and calling it your design?

The point of the exercise is to force participants to choose drivers that are well behaved and well matched to begin with. I actually tried to convince Wolf to change the challenge to 3 components, knowing full well that all entries would be severely compromised at that point. I would really enjoy seeing where people choose their compromises and how they are recieved by the audience.

Dan

[rpb]

It depends on the outcome, but I Ihaven't won any of my own themes, and I also don't vote. If I felt it was warranted, I would post my impressions about being unsatisfied with the results, and publish the original as heard, and an improved version. The thing about this challenge is that it can display upgrade improvement paths readily. I have heard 5part systems sound great, top of my head is Chuck's Misfits, and it would fit the criteria.

Later,
Wolf

OK, you win, but just to be stubborn, I looked at the Misfits thread. Part count was 7, not 5. The schematic shows 6 parts. It's 7 with the resistor that is not shown in the schematic. (I don't think it's shown. There is one resistor in the schematic, but that series x-over is confusing.)

Here's a quote from Chuck..

Re: Misfits: An economical 2way tower

The dip might be baffle induced but I am more inclined to belive it's more of an artifact of the measurement. More of a room problem than anything else.

The tweet is really nice and one that I will be using again. Easy to work with, just the right amount of sparkle at the top. I only had to use a single series resistor to level match it to the woofer. And my measured response (frequency and t/s) matched extremely well.

[Billet]

My Coaxials that I played at this years InDIYana event have six parts. I could probably get it down to 5 parts without any trouble at all. I was quite happy with the sound. It can be done...