ScanSpeak 15W/4531G00 + D3004/660000 = Revelation Two – Monitor MkII

[gornir]

Hi everyone,

Finally I've found some time to publish the Revelation Two – Monitor MkII loudspeaker. Actually it has been more or less finished for some time now, but other things have come in between like work and some family quality time! 😛

Revelation Two – Monitor MkII

The Revelation Two – Monitor MkII loudspeaker uses two of my favorite driver units, the ScanSpeak 15W/4531G00 mid-woofer and the ScanSpeak D3004/660000 tweeter. Even though these drivers are quite expensive, I think they are worth its price and they deliver top notch sonic performance.

The ScanSpeak 15W/4531G00 is one of the smoothest driver I’ve ever measured and is completely without any nasty cone break-ups and it’s very well suited for shallow sloped filters like the second-order Linkwitz-Riley I’ve used in this design.

The D3004/660000 tweeter has a low distortion profile and is also a perfect match for the second-order cross-over filter I’ve used in this design.

I’m a fan of non-complex cross-over filters and I cannot say that this cross-over is simple if I count the filter parts needed for it, but it isn’t really that complex as it may look like at the first glance.

The mid-woofer cross-over uses a couple of response shaping circuits and the tweeter uses a “Ladder Delay Network” circuit to time delays the tweeter so its acoustic center off-set matches the mid-woofer and makes a perfect phase behavior around the cross-over frequency with minimal phase distortion.

Besides that the cross-over is very simple with a first order filter for the mid-woofer and a second order for the tweeter together with a LCR circuit to flatten the impedance peak at the tweeters resonance frequency.

The loudspeaker can be built using two different enclosure volumes and port tunings, 11 liter or 14 liter enclosure. One thing to remember is that the baffle dimensions and driver unit layout must remain the same in both options. Build the larger enclosure by making it deeper in order to accommodate the needed extra 3 liters.

In the published design I’ve used the Parts Express 11 liter curved enclosure, which works well and looks great. Both enclosure options have great bass performance. In this design I personally prefer the smaller enclosure due to its quicker mid-bass response. The larger one is an option for those who want to dig a few Hz lower.

I’m very happy with the end result and I think I managed to use both these very fine drivers to its full potential. I might also if anyone whishes release a “Beryllium” tweeter version using the very nice ScanSpeak D3004/664000 tweeter?

Regards

/Göran

 

[speakerdoctor]

Great minds follow similar paths.

Visit the link below to check out my 'Intimates'. They also utilize a PE pre-fab'd cabinet. Mine is a 15L curved sided cabinet. I chose the cherry finish which my wife loved. I used a different SS tweeter, slightly different Revelator bass/mid and significantly different xover. IMO, these drivers are so smooth in their responses, I went with a very simple 3 pc 1st order elec. xover with NO capacitors. My design was inspired by the Sonus Faber Extrema. Efficiency is typical for a small 2-way mini-monitor at 84 dB 2.83V pink noise.

Introducing the "INTIMATES" (high WAF & quality sound)

 

[Mvauhn]

Can you describe the sonic differences between the original Revelation Two and the MK II version? Is the D3004/660000 that much better than the HDS tweeter used in the original? Thanks.

 

[gornir]

Can you describe the sonic differences between the original Revelation Two and the MK II version? Is the D3004/660000 that much better than the HDS tweeter used in the original? Thanks.

The HDS driver is a very good driver with a nice build quality and it’s hard to beat considering its modest price. The AirCirc tweeter on the other hand is in my opinion better sonically and in performance as well as in build consistency.

Is it worth 2.5 times the price of the HDS tweeter? I leave that to each and every one to decide by themselves. 😉

I haven’t listened to the two versions of the “Revelation Two – Monitor” side by side and audio memory is short. The two versions use a completely different cross-over design approach where the original “Revelation Two – Monitor” is a LR4 cross-over and the MkII uses a LR2 cross-over.

I think a successful LR2 design sounds a bit more vivid and real life with greater 3D dimensions compared to LR4 designs more dryer and neutral character, if I’m generalizing.

Both versions of the “Revelation Two – Monitor” are nice and you can consider the MkII as the premium version and the original as the budget version.

Regards

/Göran

 

[gornir]

Great minds follow similar paths.

Visit the link below to check out my 'Intimates'. They also utilize a PE pre-fab'd cabinet. Mine is a 15L curved sided cabinet. I chose the cherry finish which my wife loved. I used a different SS tweeter, slightly different Revelator bass/mid and significantly different xover. IMO, these drivers are so smooth in their responses, I went with a very simple 3 pc 1st order elec. xover with NO capacitors. My design was inspired by the Sonus Faber Extrema. Efficiency is typical for a small 2-way mini-monitor at 84 dB 2.83V pink noise.

Introducing the "INTIMATES" (high WAF & quality sound)

Congratulations, you have used two very fine drivers and an equally nice enclosure! 😀

I'm a bit surprised that the filter worked out sonically for you, but as always, trust your ears. 🙂

Regards

/Göran

 

[gornir]

Revelation Two – Monitor MkII BE!

I’ve published the ScanSpeak ”Beryllium” tweeter version of the Revelation Two – Monitor MkII loudspeaker design and the details can be found here:

Revelation Two – Monitor MkII BE

The two versions are similar, but the 600$ more expensive Beryllium version elevates the already very good sound quality a couple of notches.

Which of the two versions should you choose?

The textile dome version has better price/performance ratio, but if you are searching for the last few percent of better performance, slightly different tweeter character and isn’t price sensitive, go for the Beryllium version!

More details about the ScanSpeak “Textile” and “Beryllium” tweeter dome differences can be found here:

ScanSpeak Textile Dome vs Beryllium Dome!


Regards

/Göran

 

[tf1216]

Gornir,

I love how you described the crossover design. The overlay of the crossover with and without the response shaping is genius. It's the first time I have seen details presented in that manner. Thank you much for helping me and, potentially, other newbies learn how parts affect measurements.

I check your site every single day for an update to your Grand Reference speaker. I'm waiting very (un)patiently!

 

[supernet]

Nice project Gornir. With parts express cabinet it looks like high end commercial loudspeaker.

Interesting option may be 2.5 way design with 6600 tweeter, targeting much more bass weight and better sensivity. What do you think?

 

[gornir]

Gornir,

I love how you described the crossover design. The overlay of the crossover with and without the response shaping is genius. It's the first time I have seen details presented in that manner. Thank you much for helping me and, potentially, other newbies learn how parts affect measurements.

I check your site every single day for an update to your Grand Reference speaker. I'm waiting very (un)patiently!

Thank you! 🙂

Unfortunately I haven't had time to do any cross-over simulations yet for the Sequence Three - Grand Reference , but I literally did hundreds of measurements during the Christmas holidays to be used for the cross-over design.

I've been working on a design around the SB Acoustics Satori mid-woofer and a coaxial mid which I will use in a small 3-way.

Regards

/Göran

 

[tf1216]

You are welcome. The Satori 3-way sounds like it is a fun project. Can you share with us where the coaxial driver came from?

 

[gornir]

Nice project Gornir. With parts express cabinet it looks like high end commercial loudspeaker.

Interesting option may be 2.5 way design with 6600 tweeter, targeting much more bass weight and better sensivity. What do you think?

Thanks!

With the 15W/4531G00 it's a no go, but with the 15W/8530K00 it would work even though the sensitivity would be about the same.

The Revelation Two - Monitor MkII is quite sensitive considering its size and can be played loud and has an incredible bass despite its small size. With a 2.5-way you would probably be able to play even louder.


/Göran

 

[gornir]

You are welcome. The Satori 3-way sounds like it is a fun project. Can you share with us where the coaxial driver came from?

Actually, the Satori is a 2-way stand-mount with a stepped baffle and a box around 20 litres.

For now the coaxial is a small secret. 😉

I will do some measurements and take some pictures before I reveal the model of it. I'm also waiting for the woofers to be used in this 3-way.

/Göran

 

[tf1216]

gornir,

Have you ever tried a capacitor-less crossover? To this day I still see folks reference the Sonus Faber Extrema producing some of their favorite musical experiences. I don't know of another speaker with a capacitor-less crossover so I don't know where else to go searching for more information.

 

[gornir]

gornir,

Have you ever tried a capacitor-less crossover? To this day I still see folks reference the Sonus Faber Extrema producing some of their favorite musical experiences. I don't know of another speaker with a capacitor-less crossover so I don't know where else to go searching for more information.

You mean something like this!

Even though these drivers are extremely well behaved, there are a lot of issues with this kind of cross-over. In this case a very low cross-over point, tweeter only down 12dB @ fs and very low impedance of 2.5Ohm etc.

This was just a quick and dirty cross-over sim and I haven't tested it, but I'm sure you see what I'm talking about.

I've seen this cross-over type circulating around the web as a magic cross-over that can be used with almost any drivers, without measuring them and designing by ear only.

Sorry I don't think it will result in a successful design 99% of the time. 😉

/Göran

 

[tf1216]

Why did you put the resistor in parallel with both drivers? What happens if you pad the tweeter, to match the woofer's sensitivity, with a resistor in series?

Thank you for conducting the study.

 

[speakerdoctor]

gornir,

Have you ever tried a capacitor-less crossover? To this day I still see folks reference the Sonus Faber Extrema producing some of their favorite musical experiences. I don't know of another speaker with a capacitor-less crossover so I don't know where else to go searching for more information.

I have tried it. Have you read my post #2 above and followed the link I provided?
There is a price to pay for doing the SFE xover topology and that is in efficiency. Much heat is given up by the tweeter's series resistor. If you can deal with that (I did) by finding a way to keep it cool and also provide the watts to drive an inefficient DIY speaker, then go for it. Sonus Faber contracted some very special drivers to be built to go into the Extrema. They were of very high efficiency so the final result would still be acceptable for most of the high end market. The Extrema is still a very much sought after speaker on the used market.
What gonir has shown in the his last post is a series xover topology which is different from the SFE in one important way. In a series configuration it has been pointed out by others more knowledgeable than I that there is the potential for significantly more electrical interaction between the drivers than with a conventional parallel topology. See this link for a discussion on the topic of series resistors.
http://www.diyaudio.com/forums/multi-way/207301-how-series-crossovers-function.html

Another interesting link: Series vs. Parallel Crossover Networks

 

[tf1216]

speakerdoctor,

I have read your thread about your "Intimates" speaker. I posted on PETT wanting to do a similar build as yours. I intend on spending some time learning SolidWorks before getting to ahead of myself with a build. gornir, has the perfect drivers for the capacitor-less (ie. SFE) crossover plus he has constructed some beautiful crossover designs utilizing capacitors. It would wonderful to hear his thoughts about each approach.

 

[speakerdoctor]

Oh, so you're the guy over at TT who wanted (past tense?) to build the Intimates.
I've shown the driver's I selected and used with the SFE xover do indeed work. What more convincing do you need? 😕
I have provided all the info needed to build the Intimates. They'll run you about $1200 retail parts to build.

 

[tf1216]

One reason for not building the "Intimates" is because I think I want to design and build my next speaker from scratch. One big problem for me is that this speaker will be for a living room. The GF would like the speaker to be white and not "square". I have decided to give SolidWorks a try to model up the enclosure. I was thinking in the meantime I would try to find someone's opinion on Scan-Speak or AudioTechnology drivers in the configurations discussed above. Right now I am feeling these are two of the only makes of drivers that can accomplish your crossover design successfully. On a side note, I am partial to AudioTechnology drivers. I currently use the 18H in my 3-ways at home.

 

[Baldin]

Hi gornir

Look very good 🙂
Where do you buy the cabinets?
PartsExpress or something closer to home 🙂

Thanks Baldin 🙂