Soldering Luxury Speaker Wire
I really wanted to solder the wires on, but I'll abide by your recommendations. I found some good tinned red copper spade crimp connectors. I might drop a little solder on those to make myself feel better.
I am loving the quality look and feel of the NVX Silver Tinned 16AWG Seaker Wire. It has a bunch of tiny strands, and the rubber is really nice. It's a luxury speaker wire. Does it sound any better than a lamp cord, probably not. It's $15 for 25 foot of it. I'll probably move to their 12 Gauge Version for future external speaker wiring of 8ft or more and their interconnects might be worth a try.
I really wanted to solder the wires on, but I'll abide by your recommendations. I found some good tinned red copper spade crimp connectors. I might drop a little solder on those to make myself feel better.
I am loving the quality look and feel of the NVX Silver Tinned 16AWG Seaker Wire. It has a bunch of tiny strands, and the rubber is really nice. It's a luxury speaker wire. Does it sound any better than a lamp cord, probably not. It's $15 for 25 foot of it. I'll probably move to their 12 Gauge Version for future external speaker wiring of 8ft or more and their interconnects might be worth a try.
FAST TL Sound Dampening & Tunning
Here are some pictures of the dampening and tuning materials installed. I put a layer of 80 mil butyl on the back panel, over the dagger cone and all around the area near the woofer. I then hot glued open cell foam in the front chamber and everywhere the woofer directly hits. I tried to get 40% overall coverage with the foam. Most of that being near the woofer and at the top of the labyrinth. The cone has ½ thickness melamine sponges on the inside and a little poly-fill. The chamber and upper ¼ of the speaker is all filled with poly-fill. The turn at the bottom has foam and a soccer ball sized bunch of poly-fill.
Here are some pictures of the dampening and tuning materials installed. I put a layer of 80 mil butyl on the back panel, over the dagger cone and all around the area near the woofer. I then hot glued open cell foam in the front chamber and everywhere the woofer directly hits. I tried to get 40% overall coverage with the foam. Most of that being near the woofer and at the top of the labyrinth. The cone has ½ thickness melamine sponges on the inside and a little poly-fill. The chamber and upper ¼ of the speaker is all filled with poly-fill. The turn at the bottom has foam and a soccer ball sized bunch of poly-fill.
FAST TL Crossover & Binding Posts
Here are pictures of the crossover installation and the temporary wiring. We will do the final wiring after we have the matching speaker and do the staining. I’m still waiting on the 18AWG for the full range. You can clearly see where I made the mistake of letting the binding posts touch the foil of the butyl in the third picture. I’m sore from kicking myself for overlooking that and damaging my amp. I like the little standoff posts because you can slip the wiring down behind if you want to and the crossover is easy to remove. You could hide the posts screws underneath with a little extra work but I didn't see a need.
Here are pictures of the crossover installation and the temporary wiring. We will do the final wiring after we have the matching speaker and do the staining. I’m still waiting on the 18AWG for the full range. You can clearly see where I made the mistake of letting the binding posts touch the foil of the butyl in the third picture. I’m sore from kicking myself for overlooking that and damaging my amp. I like the little standoff posts because you can slip the wiring down behind if you want to and the crossover is easy to remove. You could hide the posts screws underneath with a little extra work but I didn't see a need.
Nice work on the foam padding and stuffing. By all means, use the nice flexible high strand count wiring internally. The flexible wires like the premium stuff shown can be soldered as it presents very little mechanical strain. However, removing is a pain to do work on the crossover. Not a big deal once permanent. The standoffs on the crossover look good. Just make sure it’s sturdy and doesn’t let the assembly vibrate. Finally, is there sponge rubber gasket material on the back panel joint?
How does it sound?
How does it sound?
Hi Studiomic,
This is all looking very promising. How much more time do we expect a stereo pair to be available for your listening impressions?
I was talking to Vunce last night and he said the combo of the Hakuin preamp, the Alpha Nirvana, and the 10F/RS225 FAST TL was simply unbelievable. It has resolution and detail, a gorgeous midrange with warmth and lifelike soul and impactful deep deep resolving bass. It was rattling the windows with deep yet articulate bass.
I can’t wait to hear my own set in my listening room.
This is all looking very promising. How much more time do we expect a stereo pair to be available for your listening impressions?
I was talking to Vunce last night and he said the combo of the Hakuin preamp, the Alpha Nirvana, and the 10F/RS225 FAST TL was simply unbelievable. It has resolution and detail, a gorgeous midrange with warmth and lifelike soul and impactful deep deep resolving bass. It was rattling the windows with deep yet articulate bass.
I can’t wait to hear my own set in my listening room.
I'm not sure how long the woodwork will take. It's now an assembly line job to build 5. I'm just as excited about hearing the stereo pair. The bass does have terrific punch and hit. It's incredibly detailed throughout it's range. I have not tried to rattle any windows, but I'm sure that would be easy with two speakers. I also want to do some measuring and tweaking on the these. I feel the bass is slightly overpowering the mids and highs for some types of music. Nice problem to have! Not much you can do if you don't have enough bass. It might be my hearing or the fact that I'm use to AMT super tweeters. Only testing will tell the truth. I'm going to add a Schiit Modi to the signal chain to adjust the bass and treble before messing with anything else. FYI: They are not near the back wall.
Mono FAST TL Listening Impressions
Here is my listening setup in the studio. The Studio is 23'X23' with carpet on all but the cyc. Ceiling is 10'. There are some terribly reflective cabinets but they are far away. It's a decent listening room. Speaker is about 1/3 into the room from back wall and I sit 1/3 from the other wall.
The signal chain goes like this:
DIY Roon ROCK Server playing from Tidal & Qobuz.
Pagent USB Cable to Pro-Ject Box S2 DAC Pre.
SKW RCA Interconnect to McGary SA2 80WPC Tube Amp.
Note: I've been testing a bunch of other amps.
Power Cables are all high quality and I use a WAudio AC Power Filter/Surge.
Note: Amp is plugged into surge only side of WAudio.
Here you see the McGary SA2 opened up for inspection after it got smokey from the speaker terminals touching the butyl foil. On the floor, you see an Adcom GFA 555 Amp we tested with a XRK DCA (desktop class amp) as a Pre amp.
All of the different amps and pre-amp combinations gave the FAST TL their own flavor, and I started to get a feel for why this speaker is so fantastic.
I'm not a speaker expert and these are just my opinions! I have a lot of OK speakers and have listened to some very high end stuff at dealers, audio shows & hifi club meetings. It is clear to me that the XRK FAST TL is competing at a very high level. It sounds like a very expensive speaker.
The first thing I have to mention is that this speaker is not very sensitive and requires a min of 50WPC from an AB amp. It's probably going to be a struggle with 35-40W tube amps. It's a close call and I look forward to trying a pair of these with a 40W vintage tube amp. I think 75WPC is probably perfect and 100WPC would give you headroom. Your mileage may vary.
I need to mention that I'm listening to only one speaker. Maybe a low wattage amp is OK when you have two speakers going? Probably not, but worth mentioning. I'm also not able to get a full picture of what the stereo sound and imaging be like. I'm guessing a lot more of a good thing.
I have to guess at how loud two of these will get. I can make one play as load as I would want two to play, without distortion. This is for a medium sized room and standing only 10 feet from it. I'm thinking two are going to be loud enough for anyone!
The detail and separation is amazing. There is a ton of nice low bass. It's incredibly articulate bass like I've never heard from a sub, or any speaker for that matter. The mids and highs are strong and clear. I do feel something is missing in the treble. I want more there.
I think it's me: I probably don't hear the highs as well, due to shooting guns and attending rock concerts in my youth. I'm also use to AMT super tweeters. It cold also be a case of the amazing bass overpowering the mids and highs. More testing will tell us and we will get it tuned to my liking either by adjusting the damping or changing the crossover.
XRK Said: "You can play with the 10F attenuation to taste. It is R1 currently 4.7ohms over R2 4.7ohms. A 50:50 divider. Maybe change the R1 to 2.2ohms and R2 to 6.8ohms or 10ohms. That will brighten it up a bit. We will need to measure to really know. But the TL will increase bass below 150Hz or so. Maybe you are right that it is overpowering the mids."
Thank you all for your help and support. This project has been really fun so far. I feel privileged to be the first to hear a plywood FAST TL. I can't wait for the two other guys most involved to get their speakers and post their listening impressions.
Here is my listening setup in the studio. The Studio is 23'X23' with carpet on all but the cyc. Ceiling is 10'. There are some terribly reflective cabinets but they are far away. It's a decent listening room. Speaker is about 1/3 into the room from back wall and I sit 1/3 from the other wall.
The signal chain goes like this:
DIY Roon ROCK Server playing from Tidal & Qobuz.
Pagent USB Cable to Pro-Ject Box S2 DAC Pre.
SKW RCA Interconnect to McGary SA2 80WPC Tube Amp.
Note: I've been testing a bunch of other amps.
Power Cables are all high quality and I use a WAudio AC Power Filter/Surge.
Note: Amp is plugged into surge only side of WAudio.
Here you see the McGary SA2 opened up for inspection after it got smokey from the speaker terminals touching the butyl foil. On the floor, you see an Adcom GFA 555 Amp we tested with a XRK DCA (desktop class amp) as a Pre amp.
All of the different amps and pre-amp combinations gave the FAST TL their own flavor, and I started to get a feel for why this speaker is so fantastic.
I'm not a speaker expert and these are just my opinions! I have a lot of OK speakers and have listened to some very high end stuff at dealers, audio shows & hifi club meetings. It is clear to me that the XRK FAST TL is competing at a very high level. It sounds like a very expensive speaker.
The first thing I have to mention is that this speaker is not very sensitive and requires a min of 50WPC from an AB amp. It's probably going to be a struggle with 35-40W tube amps. It's a close call and I look forward to trying a pair of these with a 40W vintage tube amp. I think 75WPC is probably perfect and 100WPC would give you headroom. Your mileage may vary.
I need to mention that I'm listening to only one speaker. Maybe a low wattage amp is OK when you have two speakers going? Probably not, but worth mentioning. I'm also not able to get a full picture of what the stereo sound and imaging be like. I'm guessing a lot more of a good thing.
I have to guess at how loud two of these will get. I can make one play as load as I would want two to play, without distortion. This is for a medium sized room and standing only 10 feet from it. I'm thinking two are going to be loud enough for anyone!
The detail and separation is amazing. There is a ton of nice low bass. It's incredibly articulate bass like I've never heard from a sub, or any speaker for that matter. The mids and highs are strong and clear. I do feel something is missing in the treble. I want more there.
I think it's me: I probably don't hear the highs as well, due to shooting guns and attending rock concerts in my youth. I'm also use to AMT super tweeters. It cold also be a case of the amazing bass overpowering the mids and highs. More testing will tell us and we will get it tuned to my liking either by adjusting the damping or changing the crossover.
XRK Said: "You can play with the 10F attenuation to taste. It is R1 currently 4.7ohms over R2 4.7ohms. A 50:50 divider. Maybe change the R1 to 2.2ohms and R2 to 6.8ohms or 10ohms. That will brighten it up a bit. We will need to measure to really know. But the TL will increase bass below 150Hz or so. Maybe you are right that it is overpowering the mids."
Thank you all for your help and support. This project has been really fun so far. I feel privileged to be the first to hear a plywood FAST TL. I can't wait for the two other guys most involved to get their speakers and post their listening impressions.
Thanks for the detailed listening impressions. One way to add top end to this is to make the RS225 a coaxial with a dome tweeter where the phase plug is. This has been done by 5th Element. There is a particular brand / type dome that fits perfectly. It sounds like the TL is working well according to the design which has an F3 of 32Hz. The nice thing about a tapered TL is that the bass is very clear and articulate. You can hear micro structure within the bass peak sometimes.
Phase Plug Tweeter
Norman B, SilverD - Thank you for the info. I was thinking there might be a time alignment issue if the tweeter sits back that far. You might be able to use a tube to bring it out parallel with the front of the speaker.
The RSX Project uses a 10" RS270 instead of the 8" RS225, so the plug might be bigger and give more space. That 10" RS270P-8A Paper Woofer is an interesting driver. It's frequency response is 23-6K Hz with 87.5 db sensitivity. It's off topic, but I'd love to know more about this 10" woofer and replacing the plug with a tweeter.
Staying on the topic of the FAST TL, I'd like to find a small enough super tweeter to fit in the phase plug. This might be the addition to the FAST TL that makes it absolutely amazing, instead of just really really really good.
Norman B, SilverD - Thank you for the info. I was thinking there might be a time alignment issue if the tweeter sits back that far. You might be able to use a tube to bring it out parallel with the front of the speaker.
The RSX Project uses a 10" RS270 instead of the 8" RS225, so the plug might be bigger and give more space. That 10" RS270P-8A Paper Woofer is an interesting driver. It's frequency response is 23-6K Hz with 87.5 db sensitivity. It's off topic, but I'd love to know more about this 10" woofer and replacing the plug with a tweeter.
Staying on the topic of the FAST TL, I'd like to find a small enough super tweeter to fit in the phase plug. This might be the addition to the FAST TL that makes it absolutely amazing, instead of just really really really good.
This little TB tweeter might fit.
13-1761S - 13mm Tiny Tweeter - TB SPEAKER CO., LTD.
Tang Band 13-1761S 1/2" Silk Dome Tweeter Pair
Or this SBAcoustics:
SB14ST-C000-4 / Fabric – Sbacoustics
But....
The 10F is quite a good driver, the combination of running the woofer higher up, and pass it on to a small tweeter would have to be very good to surpass the 10F on its own at the range it is working in X's design.
Also, TB has a coax of 8":
W8-2314 - 8” Paper Coaxial Full Range - TB SPEAKER CO., LTD.
13-1761S - 13mm Tiny Tweeter - TB SPEAKER CO., LTD.
Tang Band 13-1761S 1/2" Silk Dome Tweeter Pair
Or this SBAcoustics:
SB14ST-C000-4 / Fabric – Sbacoustics
But....
The 10F is quite a good driver, the combination of running the woofer higher up, and pass it on to a small tweeter would have to be very good to surpass the 10F on its own at the range it is working in X's design.
Also, TB has a coax of 8":
W8-2314 - 8” Paper Coaxial Full Range - TB SPEAKER CO., LTD.
I contacted 5th Element about the RS225 coax. My memory failed me - he made a coax with the B&W FST mid range, not RS225. But he does use the RS225 a lot so I got the two mixed up. The trick is how to remove the phase plug? I bet it is just screwed on with a threaded rod in the back. Probably some loctite to hold it in place. Lots of 1in overall dia tweeters available. But the time alignment might not be optimal.
The SB14ST looks pretty compact and might be a perfect fit.
The SB14ST looks pretty compact and might be a perfect fit.
RS225 AMT Tweeter Mod
AMT Mini-8 Air Motion Transformer Tweeter
Here is a mock-up of the RS225 woofer with an AMT Tweeter taped to the phase plug. I believe it could also be attached farther back as to not block any sound waves from the woofer. I do like the idea of having it flush with the front of the speaker box like it would normally be mounted.
I found 6 dome tweeters that are small enough to place this way as well, but my choice would be this AMT. This is an easy modification and there are plenty of options for how to do it.
I just started exploring this idea and any advice would be welcome. Am I messing up the woofer by removing the phase plug? What are the best mounting options for timing & phase? Any other issues I should know about?
XRK - Is there an easy way to modify the XO to test this? Where would we cross-over at? How will this effect imaging and timing of the FAST TL.
I'm excited about this as possibility for a number of projects.
AMT Mini-8 Air Motion Transformer Tweeter
Here is a mock-up of the RS225 woofer with an AMT Tweeter taped to the phase plug. I believe it could also be attached farther back as to not block any sound waves from the woofer. I do like the idea of having it flush with the front of the speaker box like it would normally be mounted.
I found 6 dome tweeters that are small enough to place this way as well, but my choice would be this AMT. This is an easy modification and there are plenty of options for how to do it.
I just started exploring this idea and any advice would be welcome. Am I messing up the woofer by removing the phase plug? What are the best mounting options for timing & phase? Any other issues I should know about?
XRK - Is there an easy way to modify the XO to test this? Where would we cross-over at? How will this effect imaging and timing of the FAST TL.
I'm excited about this as possibility for a number of projects.
That is neat.
You can see the phase shooting up to +45 degrees past 5k in the 10f.
I think I read in Dunlavy stuff that you need a tweet that goes way up in response to not have an up creeping phase.
Honestly, for alignment, I think a dome tweet “should” be even further back.
But your ears may not care.
And it may sound better if the phase is backward on the supertweet.
Seen speakers not quite time aligned do this.
When my b103 and cat378 were not time aligned (physical acoustic centered), I had a hard time hearing a suck out when reversing the phase of the tweet. Once lined up it was easily heard.
You can see the phase shooting up to +45 degrees past 5k in the 10f.
I think I read in Dunlavy stuff that you need a tweet that goes way up in response to not have an up creeping phase.
Honestly, for alignment, I think a dome tweet “should” be even further back.
But your ears may not care.
And it may sound better if the phase is backward on the supertweet.
Seen speakers not quite time aligned do this.
When my b103 and cat378 were not time aligned (physical acoustic centered), I had a hard time hearing a suck out when reversing the phase of the tweet. Once lined up it was easily heard.
Just put a circa 1uF cap in series and maybe a resistor if needed to tame the level. Add that in parallel to the tweeter output of the XO. Just tape it to the box between the two drivers and see how you like it before performing surgery on the phase plug of the RS225. There is no guarantee this won’t mess up the incredible flat response of the speaker. It most likely will mess with it unless a full 3 way crossover is developed. But your ears may like the extra added “air”.
Thank you. I'm not positive this is something I want to do on the FAST TL but It's in my nature to always want more or different. I do not want to start from scratch on the XO or mess up the flat response. We will know if the bass is heavy after running some tests.
I will give the AMT a try next time I open the box or have another speaker to ready. I'll send some pics of the setup and my impressions of the AMT test.
I do think it could be a good idea to put a Tweeter in the center of the RS225 or RS227. I believe the RS227 could pair well with a Morel ET448 dome mid/tweeter. It would give you a "single source" with a wide range. It should be pretty flat if crossed at around 1000hz. Sorry, I'm off topic again.
All I have to report on the FAST TL is that it's very enjoyable. I did get an Amazon box with the thin aluminum business card blanks, 18Ga OFC wire and tinned red copper connectors. I'm going to use the aluminum behind the terminals to protect the wood & for looks. I'll be sure to insulate the terminals if this time....LOL..Crying Inside.
I'm looking at stain colors and thinking a warm gray will be nice. Something like this:
I will give the AMT a try next time I open the box or have another speaker to ready. I'll send some pics of the setup and my impressions of the AMT test.
I do think it could be a good idea to put a Tweeter in the center of the RS225 or RS227. I believe the RS227 could pair well with a Morel ET448 dome mid/tweeter. It would give you a "single source" with a wide range. It should be pretty flat if crossed at around 1000hz. Sorry, I'm off topic again.
All I have to report on the FAST TL is that it's very enjoyable. I did get an Amazon box with the thin aluminum business card blanks, 18Ga OFC wire and tinned red copper connectors. I'm going to use the aluminum behind the terminals to protect the wood & for looks. I'll be sure to insulate the terminals if this time....LOL..Crying Inside.
I'm looking at stain colors and thinking a warm gray will be nice. Something like this: