RS225 as OB midrange

[mordensiur]

Greetings

I have got some ideas to build OB 3-way. I started by reading Linkwitz website. After some time I came to some conclusions:
- 27tbfc/g as tweeter - I am using it now and ;x( ...
- the best option for midrange ( and awiable in Europe ) is w22ex
There is one disadvantage - price I think about replacing it by Dayton rs225.
I am plannig active crossover.
Is it good idea to replace w22 by rs225 ? If not - why?

[cotdt]

Why not a Peerless Exclusive 8" or an MTM with a pair of 7's?

I would pick something different from the W22EX just to be different, but no doubt it is a great driver.

[mordensiur]

I forget to say that I want to use hard-cone driver.

[HareBrained]

No one is going to stop you from trying the RS225 in a dipole. It's a very solid driver but it does have a low upper frequency limit. Stated upper limit is 2000Hz. I believe it to be lower. Not impossible to use with 27/g but I believe there are better options. All of the RS drivers would work for a midrange and the RS225 would be down on the list. I like the RS150 better for this.

Why the hard cone?

The SB Acoustics SB17 would be an excellent low distortion driver, just to provide another option.

[severian]

Mordensiur,

Mark K is currently working on an OB speaker with RS225 and Seas 27TBFC/G in a fully active WWtWW 2.5 way. Looks like an interesting project. I also have some RS225 that I need to use in a project . I hope he doesn't mind if I post the link here.

http://www.audioheuristics.org/current_project/whats_new.htm

JC

[Mark K]

Actually, as a dedicated midwoofer for open back, the rs225 is an excellent choice. True, the Seas Excel is marginally better-but at a very high cost. Certainly if you need just one, you might still be tempted to get the Excel. In my case, no chance I'd buy 8 Excels.

There is a high Q dip around 1600-1700, so you do need to try to cross below this, or at least bury this dip in the xover. (i.e. I would cross at or below 1600). The seas 27tbfc/g is easily up to this.

The question is how low do you want to go? The RS150 and 180 obviously won't cross as low. So the question becomes, how low do you want to cross?

[Undefinition]

Greetings

I have got some ideas to build OB 3-way. I started by reading Linkwitz website. After some time I came to some conclusions:
- 27tbfc/g as tweeter - I am using it now and ;x( ...
- the best option for midrange ( and awiable in Europe ) is w22ex
There is one disadvantage - price I think about replacing it by Dayton rs225.
I am plannig active crossover.
Is it good idea to replace w22 by rs225 ? If not - why?

I know it's not exactly the direction you wanted to go, but I also wanted to do an OB design with a hard-cone midrange. I chose the Dayton RS125 because I had no doubt it could cross as high as I needed it to.

http://undefinition.googlepages.com/diy-sunflowers

The RS150 is hard to cross above about 2000 Hz, and the RS225 is basically impossible to cross that high. Mark K is the only soul brave enough to publish a design using the RS225 crossed to a tweeter, which he did pretty low.

I do understand that the RS225 is similar in size to the mids in the Orion, so the choice makes sense. But keep in mind that Linkwitz uses some crazy active crossover magic to get it to cooperate (and crosses LOW)

[cotdt]

I forget to say that I want to use hard-cone driver.

then there is also the accutons. though i think it's kind of weird using expensive low distortion drivers in a dipole, which have a lot more distortion all else equal.

[Mark K]

then there is also the accutons. though i think it's kind of weird using expensive low distortion drivers in a dipole, which have a lot more distortion all else equal.

Look at the distortion numbers for my midrange panels. They are markedly better across the midrange. The graph is just one example-everything at 100Hz and above favors the dipole panel heavily. Now, of course I cheated and used four drivers per side. Still, it gives me the same distortion as a single 8" in a sealed box on the very low end, say 50 Hz, while markedly improving on an already low midrange distortion driver.

[cotdt]

That is quite good, and it does make sense that 4 drivers in dipole vs. single driver in box that low-end distortion would be about equal while midrange distortion would be lower in the dipole. It's an interesting project you have there and I'm keeping up with it now.

[mordensiur]

Thanks for every single post!

Now I'm using L18+27tbfc/g by Zaph - great combo.
There is option that I can use these drivers. I am plannig to use 12'-15' woofer in H-frame, and I think that lower crossing point = better - in this situation. To cross about 120 Hz like Linkwitz we need singificant Sd. L18 may be to small - but I don't know it for sure. Troels Graversen uses 7' in OB not lower than 300 Hz.
I want to use midrange not higher than 1,5 kHz - maybe lower - even 1,2 like Mark.
I am going to use software crossover and DRC plugins to get active correction - I hope it will work. There is just no option for notch filters
I think that low distortion is reception for great sound - so that I want to use Excel Accutons have similar price unfortunately...
My ideal reference speaker is:
27tbfc/g ( one of the best tweeters at any price...) + w22ex ( low distortion and it is just beautiful ) + Precision Devices 2150 ( King of Speakers - you know ... ) in OB

Whet budged is not as big as our dreams there is a problem. Maybe making it by steps would be a better option:
STEP ONE: 27tbfc/g + w22ex closed or in back loaded horn with active crossover and correction
STEP TWO: shipping PD 2150 when the money will come ( damned financial crisis... )

Another option is the idea I started posting here. The question is: how much better is w22ex than rs225 in 120-1500Hz range, or is the increase is worth to make the price 4x higher ( like in Poland where I am writing from )?

[Davey]

I think you should be able to get good results with the RS225 as an open-baffle midrange. Here's a photo of a project I was diddling with recently. I got side-tracked on something else but I briefly had the system playing using my DCX2496. All Dayton Reference drivers. Really nice.

Dave.

[Jonasz]

Thanks for every single post!

Now I'm using L18+27tbfc/g by Zaph - great combo.
There is option that I can use these drivers. I am plannig to use 12'-15' woofer in H-frame, and I think that lower crossing point = better - in this situation. To cross about 120 Hz like Linkwitz we need singificant Sd. L18 may be to small - but I don't know it for sure. Troels Graversen uses 7' in OB not lower than 300 Hz.
I want to use midrange not higher than 1,5 kHz - maybe lower - even 1,2 like Mark.
I am going to use software crossover and DRC plugins to get active correction - I hope it will work. There is just no option for notch filters
I think that low distortion is reception for great sound - so that I want to use Excel Accutons have similar price unfortunately...
My ideal reference speaker is:
27tbfc/g ( one of the best tweeters at any price...) + w22ex ( low distortion and it is just beautiful ) + Precision Devices 2150 ( King of Speakers - you know ... ) in OB

Whet budged is not as big as our dreams there is a problem. Maybe making it by steps would be a better option:
STEP ONE: 27tbfc/g + w22ex closed or in back loaded horn with active crossover and correction
STEP TWO: shipping PD 2150 when the money will come ( damned financial crisis... )

Another option is the idea I started posting here. The question is: how much better is w22ex than rs225 in 120-1500Hz range, or is the increase is worth to make the price 4x higher ( like in Poland where I am writing from )?

Well, if your ultimate goal is to use the PD2150 ( :P )then I wouldn't try to save money on the W22. It's arguably the most important driver in a design like this. The cost of the PD2150 will make the extra $ on the W22 not seem so important.

You can always do a design similar to this but using for example 27TBFC/G, RS180 and double SLS12. Should make a respectable sounding dipole! :P

http://home.wanadoo.nl/dezaire/OB3W/OB3W_nl.htm

Or a semi-active version: http://home.kabelfoon.nl/~dezaire/MOB3W/MOB3W_nl.htm

[Martijn_H]

You could also use the BMS 18N850. with 13mm (52p-p mech)xmax it has more vd then the PD21". The 21" from 18sound looks also beautiful, with more xmax then the PD.

I don'understand why nobody is talking about dipole tweeters or the usage of two tweeters back to back.

I had the W22 and liked it a lot! The looks and consistency may play a role? The midrange quality is more important then the wooferquality I think.

[mordensiur]

Someday I hope to use PD2150 - but unfortunately not in this project.

w22ex is one of the lowest distorting drivers in 120-1500Hz range that I am interested in. Excels are my "old love "also...
I agree that midrange quality is very important - but I just wanted to find answers for some questions, especially like replacing w22 with rs225. I want to make project that will be good from "technical side".

[mordensiur]

You could also use the BMS 18N850. with 13mm (52p-p mech)xmax it has more vd then the PD21". The 21" from 18sound looks also beautiful, with more xmax then the PD.
.

reaching Xmax from 21' driver - my neighbours wouldn't like it

[Jonasz]

You could also use the BMS 18N850. with 13mm (52p-p mech)xmax it has more vd then the PD21". The 21" from 18sound looks also beautiful, with more xmax then the PD.

I don'understand why nobody is talking about dipole tweeters or the usage of two tweeters back to back.

I had the W22 and liked it a lot! The looks and consistency may play a role? The midrange quality is more important then the wooferquality I think.

I use two W22 per side with a RS28. I will also add a rear RS28 shortly. :P

[mordensiur]

Using 21' woofer makes situation comfortable, because there is no possibility to lack of low frequencies Escpecially with DRC. Then we can think about other thinks then technical stuff - my inspiration: http://www.humblehomemadehifi.com/Serious-Sub.html

I've written:
Whet budged is not as big as our dreams there is a problem. Maybe making it by steps would be a better option:
STEP ONE: 27tbfc/g + w22ex closed or in back loaded horn with active crossover and correction
STEP TWO: shipping PD 2150 when the money will come

With my present budget this is only way to built my own reference speaker

I dont want to make a new topic so I'll ask here. What is the best enclosure option for w22ex? Closed box and back horn on the other hand, or maybe TL? Adding some SPL could be good for this driver. I'm going to use active crossover with DRC, so I can eqalize both types of box. The question is what type is better.