Sealed 2-way All Dayton Build (1" and 8" Drivers)

Hello,

I am new to the community and this will be my first build. Currently using a powerful AVR and ported 5.1 speakers in my living room and I would like to upgrade the latter. I am convinced I want sealed speakers, because my sub is sealed and I like their sound better in general. So, I thought of building a 2 way 1" + 8" combination (like Kef's vintage C series). For the woofer, I chose Dayton RS225P-8A and for the tweeter, DC28FS-8. I am not sure which crossover to pick yet, but probably the Dayton two way with the frequency at 2500hz (2nd order). For this first project, I want to avoid building a crossover as much as possible.

1- What do you think of Dayton RS225P-8A's mid performance and do you think the xover at 2.5K would be enough?

2- Could you give me some idea on the enclosure design? I would really appreciate your help on this one, I am not sure which volume would be right with this woofer.

Thanks in advance.
 
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I don't blame you if you do not want to figure out how to measure and design a crossover, but you will have infinitely better sound if you build something that has been designed by a competent designer. Off the shelf crossover rarely (almost never) achieve acceptable results.
 
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  • An 8-inch woofer is going to start beaming below 2Khz so you will want to cross over less than that. BEAMING
  • The RST28F-4 can cross over as low as 1.8Khz, probably even 1.6Khz - The build that jerome69 linked crosses over too high, in my opinion.
  • An "off the shelf" crossover almost never works as Mordikai has point out.
  • Sorry, I do not know of an existing two-way design using the RS225P-8A that I can recommend. Too bad too, because the RST28F-4 and RS225P-8A would make a good budget 8-inch two way.
 
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1- What do you think of Dayton RS225P-8A's mid performance and do you think the xover at 2.5K would be enough?

2- Could you give me some idea on the enclosure design? I would really appreciate your help on this one, I am not sure which volume would be right with this woofer.

1. It has deacent sized magnet, but I would prefer less moving mass, below 20 g.
For xo point, I would not go above 2 kHz.

2. The example of the box show in post #3 looks like good match for this driver.
 
I am a complete beginner - so feel free to consider all of the below with sceptisism.
  • As already mentioned transitioning from an 8" woofer to a tweeter you are going to have directivty mismatch problems. To help compensate for that consider using a tweeter with a waveguide - such as Dayton Audio ND25FW. The tweeter you selected has a spec sheet FR graph that doesn't match what's in the FRD files, it's rather uneven - choose something else.
  • As for box size - PartsExpress recommends the following: Sealed Volume 0.55ft³ | Sealed F3 74Hz - I'm sure that's a reasonable suggestion
  • The crossover - will need to be custom and I can't see how it doesn't get a bit complicated - so here's one I quickly sketched up (using RS225P-8A and ND25FW). Is it reasonable - I have no idea - I'm a complete novice. Still - I think this is a more likely to succeed than a random prebuilt Xover.
Apologies to the experienced folks who may find this silly - I'm here to learn.

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Thanks a lot for the replies and the information helps a lot, but all the shared builds are ported so far. Could those potentially give me an idea about how my sealed box should be?
The "magic" of a speaker, as well as the most difficult part, is the crossover. Whether the box is sealed or vented will not change the crossover, so try to find an existing design (i.e., existing crossover) and then do what you want with the box volume. It is important to have the speaker width the same as the existing design, as well as the placement of the tweeter from the sides and top, as well as the distance between the tweeter and woofer. The xo would have been designed taking those into consideration. YOu can adjusted the height and/or depth to get the net volume that you need.

Sealed boxes are pretty forgiving, so for the RS225P something like 15 to 17 Liters should be fine.
 
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Anything else aside, the RS225P (Dayton 'Reference Series') is a high quality driver and the DC28F ('Classic Series') is OK, so there would be a mis-match in terms of sound quality between the two. It's a better match for woofers in the Classic Series such as the DC130 or DC160.

Further,the DC28F has a rather sticky dome which attracts dust, insects and fluff and is hard to clean. The mount only has three screws, which isn't ideal.

Geoff
 
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Ditto. That tweeter is likely not happy that low.

Then of course the fitment has to work. To fit an 8" 2way with average 104mm tweeter, you are already looking at more volume for things to fit in the box.

Everybody touts waveguides as being more friendly for this kind of design, but you can do more with less by careful responses of the drivers used. I my Zingers build, I rolled off the woofers pretty steep, and gradually rolled off the tweeters starting an octave early. This helps curb the mismatch, and avoids the waveguide.

13" mandatory height, plus spaces to edges and between drivers is about 15". 9" wide mandatory, plus edging, so a comfortable 10" internal wide. At 17ltrs, this leaves 7" deep internal dimensions.
I really feel this is a shoehorn for the 8" 2way variety, and at only 0.6 ft^3, is not enough volume for most to breathe. Once you add in bracing and the xover, it will just not fit very well.

If using a sealed or vented box for an 8" woofer, I would think of 20-25 ltrs would be more likely a good sealed volume, whereas 25 to 40 ltrs for a vented box or tower. I usually target 1ft^3/28 ltrs starting for this kind of speaker.
 
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I would question using 8" woofers in a sealed system that has a subwoofer. Usually the reason to go with 8" woofers is to have more bass than the typical 5" or 6-1/2" two way.

I'd go with a 5" or 6-1/2" woofer, sealed. That will also allow many more tweeters to work, as you will not need to crossover so low. Also, finding an existing design will be easier.
 
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Thanks again, all the information above is very useful. I understand now how technically you can inspire from a build that doesn't have the same enclosure type. Also, if it works better, I can assemble the crossover from a diagram, no problem there.

Regarding the smaller woofer, all of my main speakers (in the living room and in my recording studio) currently are 1" + 6,5" and I want to do something slightly different. I understand why you recommend a smaller woofer, but I am going to stick with the sealed 1" + 8". In addition, I always set the subwoofer (it is a sealed 11") to the lowest possible frequency, so I would still need good bass response.
 
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