Looking for a mid/woofer to match with a RAAL tweeter

I'm looking for a quality midrange/woofer to match with the RAAL 140-15D tweeter. The two will initially be put in a Dayton Audio prebuilt enclosure (or similar) and crossed over with a pair of subwoofers around 80-120hz. Eventually I will build a three-way enclosure and add a true woofer. The midrange/woofer will also need to work in a MTM alignment as a center channel, also in a prebuilt Dayton Audio enclosure. For crossover I'll be using the DEQX HDP-4. The tweeter crossover will be 2500-3000hz and probably 96db/octave. The speakers will be used for music as well as home theater so they will need to handle the high SPL demands of movie sound tracks.

I'm looking for recommendations on a midrange/woofer that will match well with the RAAL at the crossover frequency and can be equalized flat to at least 120hz in a 0.75 or 1.00 cubic foot cabinet. One of the characteristics of the RAAL that I'm trying to extend down to the midrange is the excellent polar response. I'd also prefer a driver available for purchase in the USA.

I'm experienced with active speakers for the last three years using the GroundSound DCN24 and now the DEQX. To date I've been using the NHT M60 and M80 speakers. This will be my first attempt at selecting my own drivers and building my own speaker. Using the prebuilt enclosures will give me time to evaluate the drivers and crossovers before deciding on the final 3-way drivers and full range cabinet.
 
Well, I kinda sound like a broken record about this, but you would be hard pressed to much better than the Neo10 since you are going active and funky freq response is not as much of an issue if you are trying passive. I have also successfully used the 70-20 and the smaller, but new version of the Neo8-S which can play lower. Only problem is that you really ought to get off of the Neo10 by about 250Hz or so, sooooooo....maybe not for you. If you use two Neo10 per side like me and you do not listen too loud, then you might get away with a 120Hz crossover temporarily. I tried mine that low on OB and they sounded very nice, but were dynamically limited. In a box it still might be your best choice. You could arrange them side by side onto a 10" square basically. Will that fit the PE cabinet?

How about a nice 18 Sound 6ND430?

6ND430 - LF Neodymium Driver

Although, now that I think about it, it wants to cross higher than that too. You'v got a tough task. To cross up at 3KHz and as low as 80Hz AND keep the sensitivity up is not easy. But I agree, that you should not cross the 140-15 any lower than 2.5-3KHz.

I would say go three way right from the start. Whatever you pick that will fit the role now, will be less than ideal once you add a woofer. Of course there are more hi-fi style drivers that would work better, but then it's such a shame to throw away good, free SPL on the Raal by adding some 88dB/SPL 6" Scan speak or something. How about a custom AT driver with extra high sensitivity? Will be pricey, but if you're already committed to the Raal, then you've got to keep up the quality anyway.

Greg
 
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ScottG

Member
2003-02-04 12:23 am
US
I'm looking for a quality midrange/woofer to match with the RAAL 140-15D tweeter. The two will initially be put in a Dayton Audio prebuilt enclosure (or similar) and crossed over with a pair of subwoofers around 80-120hz. Eventually I will build a three-way enclosure and add a true woofer. The midrange/woofer will also need to work in a MTM alignment as a center channel, also in a prebuilt Dayton Audio enclosure. For crossover I'll be using the DEQX HDP-4. The tweeter crossover will be 2500-3000hz and probably 96db/octave. The speakers will be used for music as well as home theater so they will need to handle the high SPL demands of movie sound tracks.

I'm looking for recommendations on a midrange/woofer that will match well with the RAAL at the crossover frequency and can be equalized flat to at least 120hz in a 0.75 or 1.00 cubic foot cabinet. One of the characteristics of the RAAL that I'm trying to extend down to the midrange is the excellent polar response. I'd also prefer a driver available for purchase in the USA.

I'm experienced with active speakers for the last three years using the GroundSound DCN24 and now the DEQX. To date I've been using the NHT M60 and M80 speakers. This will be my first attempt at selecting my own drivers and building my own speaker. Using the prebuilt enclosures will give me time to evaluate the drivers and crossovers before deciding on the final 3-way drivers and full range cabinet.


What you are looking for then is a small diameter driver with good excursion for it's sd and good thermal behavior.

Because it's active, efficiency isn't really an issue unless you are limiting yourself with respect to amplification.


You should also look to clean initial decay and overall low mms with a wide dispersion polar response up higher in the midrange/lower treble.

I'll recommend the Jordan JX92S (with measurements provided on Zaphaudio website in the 5" category).

Not cheap.. but then again it has a combination of virtues that mesh well with your plan (without any substantial flaws):

Unshielded JX92
 
Perhaps I should do some listening tests with my subwoofers to see how they sound above 120hz. They are NHT S80s. They were intended to be used with a DEQX and don't have any built-in equalization. Looking at the nearfield measurement it seems they could easily be crossed over at 200hz or higher. But I have no idea how they would sound. I can setup an experiment with three different profiles on my DEQX and compare.

I hadn't considered a planar like the Neo10. Might be a good choice if I can raise the subwoofer crossover.

I've looked at AudioTechnology drivers. But I'm not able to find a US distributor of the 6" driver. PM me if you know of a source. I'd rather not go through the trouble of importing them myself.
 
Because it's active, efficiency isn't really an issue unless you are limiting yourself with respect to amplification.

Correct, I'll be using solid state 250 watts per driver. Nothing exotic. My current setup with the M80s requires 4 channels of amplification for left, center plus right for a total of 12 channels. So cost would get out of hand quickly if started using boutique amplifiers.
 
Since you can achieve those brick wall type slopes with the DEQX, you might be able to raise those subs up to near 200Hz. There were built with very good drivers, so there's a chance they'll sound OK that high. I agreed with Scotts theory, I just prefer to get those attributes of low mass and quick rise/settle time from the planar rather than a light, delicate cone.

I auditioned and measured about a dozen different cone drivers from arrays of 2-3" mini drivers to high sensitivity full-range units to things like the Scan Speak 15W and a Lambda TD6 before settling on the Neo10. There's something about a good push-pull planar used correctly that has an immediacy and snap to the sound that I've heard few cones get right. My implementation is an OB with the rear wave of the Neo10 semi absorbed. It is an attempt to blend the rear radiation pattern to more closely match the Raal above and OB loaded woofer below. I think in a closed box, you will have better luck running the Neo10 a little lower, but make sure to have a good amount of Bonded Logic or other quality absorption inside the box, but spaced behind the Neo10 surface by at least a few inches.

Oh and a word of caution, IF you do try the Neo10, use crimp terminals on the ends of the wire. Don't bother soldering directly to the tabs. The diaphragm is somewhat gentle and if you are not quick or remove the wires several times, you may damage the driver from transferred heat.

Greg
 

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Great minds think alike. I have an open baffle midrange with PHL Audio 1240s in an MTM and Aurum Cantus G2 tweeters. Eminence 3015LF Neo Kappitalite woofers in H-frame mounts handle the lows. The 3-way crossovers are via a DEQX PDC2.6 HD at 175 Hz and 2500Hz. I'm using 96 dB/octave slopes.

My MTM baffle came from a P-E Dayton Audio 1 cubic ft box.

With these higher sensitivity drivers you have extra dynamic range which provides sound with body. I like it!
 

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ScottG

Member
2003-02-04 12:23 am
US
Great minds think alike. I have an open baffle midrange with PHL Audio 1240s in an MTM and Aurum Cantus G2 tweeters. Eminence 3015LF Neo Kappitalite woofers in H-frame mounts handle the lows. The 3-way crossovers are via a DEQX PDC2.6 HD at 175 Hz and 2500Hz. I'm using 96 dB/octave slopes.

My MTM baffle came from a P-E Dayton Audio 1 cubic ft box.

With these higher sensitivity drivers you have extra dynamic range which provides sound with body. I like it!



Ok, that's pretty "scary".

This is extremely close to what I asked SL to alter his Phoenix design for late in '99. :eek:
 
Oh and a word of caution, IF you do try the Neo10, use crimp terminals on the ends of the wire. Don't bother soldering directly to the tabs. The diaphragm is somewhat gentle and if you are not quick or remove the wires several times, you may damage the driver from transferred heat.

Greg

I like the look of the two Neo10s alongside the RAAL. Any concerns with them interfering with each other in the crossover band? One of the reasons I've chosen the RAAL is to get larger soundstage. My room has an abundance of absorption material (for bass) and the NHT M80s I'm using are very directional. The combination of the two has created a very tight soundstage.

I was thinking the center would be a horizontal MTM. Would I still want the Neo10s that close to the RAAL? Perhaps I could do a WMTMW for the center if I build the right enclosure.

Do the Neo10s need a capacitor for protection with the DEQX? My understanding is that the RAAL is very fragile to clicks and pops and must have a protection cap. The DEQX HDP-4 has an annoying pop when the digital input sampling rate changes (from 44.1 to 96khz for example).
 
I started out with the Raal using a large value cap(30MFd) for protection, but after the Digmoda amps proved to be dead silent on turn-on/turn-off, I've since removed the cap with no problems. I never had a cap on the Neo10. That's a tough one if the DEQX pops. Better to use one then to be safe.

You are correct about dispersion being a possible issue. The Raal will be very wide at crossover, while a pair of Neo10 side by side will be equivalent to an 8-10" driver, so at 3KHz, their horizontal dispersion will be narrow. As you can see in my set-up, it kept the Neo10 stacked, so they are more like a smaller 4" midwoofer in regards to horizontal dispersion. These are all things you could test and play with yourself. You can buy additional PE blank baffles for cheap to use for prototyping.

If you really feel ambitious and like the idea of narrowed dispersion, then maybe the side by side Neo10 would suit you if you could narrow the Raals dispersion. I wonder if you could create some kind of the large foam waveguide of sorts. Or you could try something radical and mount the Raal horizontally which would make it's width about the same as the Neo10 and do an MTM that way. I did something similar during prototyping with BOTH the Neo10's and the Raal sideways, but in this case maybe just the Raal?

Greg
 

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Maybe B&W FST? They won't play anything below 300hz or so but have excellent low distortion and a healthy 94 dB sensitivity.

Yes, it's a nice mid, but is it REALLY available? I thought B&W was cracking down on folks buying these without proof of owning one of their speakers using the driver. Kinda of like KEF pulling the plug on their coax drivers.

Greg
 
How about a pair of Seas Excel W15CH001 or Acuton C158-8-085? In a vertial MTM alignment for the left and right and horizontal for the center? I'm reading a lot of good things about the Neo10, except the low end. I like music with a lot of bass, drums and electronics. I'm also struggling to come up with a layout with two Neo10s and one RAAL that works for the center channel.

I don't think I have to be too concerned with matching the sensitiviy of the RAAL when using a dsp crossover. Correct? I just want to make sure that I pick a driver that still has good dispersion at the target crossover frequency of 2500hz.
 
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Sure, those are excellent drivers and would be fine. The Seas will have a break-up mode near 8KHz, but with those steep slopes you ought to be OK. The Accuton breakup is closer to 4KHz, so you might need an additional notch there. A vertical MTM with the 140-15 is problematic because of its height. But, hey rules are meant to be broken, right? Considering the level of quality you are considering buying and having for your end result, it might be worth your while to buy one of several drivers you are interested in and trying them all out. That's how I did it. Only way to know what suits YOU.

Or, before you commit to one decision, try the subs crossed higher in your current set-up to see how far they can go and still sound good. That way you know for sure your lower/higher limits.

Greg
 
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Sure, those are excellent drivers and would be fine. The Seas will have a break-up mode near 8KHz, but with those steep slopes you ought to be OK. The Accuton breakup is closer to 4KHz, so you might need an additional notch there. A vertical MTM with the 140-15 is problematic because of its height. But, hey rules are meant to be broken, right? Considering the level of quality you are considering buying and having for your end result, it might be worth your while to buy one of several drivers you are interested in and trying them all out. That's how I did it. Only way to know what suits YOU.

Or, before you commit to one decision, try the subs crossed higher in your current set-up to see how far they can go and still sound good. That way you know for sure your lower/higher limits.

Greg

I not sure I understand why a vertical MTM is problematic with the RAAL. Is it because the seperation of the two midwoofers is too large and they will lobe? If so I'd be happy with a vertical TMM layout and keep the MTM for the horizontal center channel. I'm certainly willing to experiment with different baffle panels. I understand that horizontal MTM is not ideal. In the not too distint future I'll be replacing my plasma with a projector. I'll then use a audio transparent screen and orient the center the same as the left and right.

I agree testing out drivers and finding one that suits me is optimal. I'm not sure how I do that. Are there places that send out loaner drivers? Or do you buy and sell drivers until you find the one you want to keep? But to be honest my subjective listening skills may not be reliable enough for me to remember what each trial driver sounded like as I cycle through them.

I'm totally sold on the DEQX. So steep filters and taking drivers to the edge of their pass band is not an issue.
 
the raal 140-15 work fine in a 6 1/2 TMT. in real world. neither from simulation expirience nor from hearing from somebody "they won`t"

first choice could be seas magnesium with accurate sound ( every instrument seems to have sharp edges, really tight bass ), seas nextel (fine too, for me a little bit more "snappy" and smoother (not muddy)), phl driver (no expierence with raal) or accuton (same as for the magnesium) or if you can get them kevlar drivrs from davis acoustics ( they tend to look a bit old skool, but the sound tight)
 
I've made a couple of changes and made a decision. I will start out with a simple tweeter over midrange configuration. Easier to build and measure. The center will still need to be MTM but that will come later after the left and right are sorted out. I tested my subwoofers at various crossover frequencies this weekend and it is seamless up to the max I tested of 180hz. Probably could go higher, but I would worry about the drivers being so far away from the midrange.

I ordered a pair of the Accuton C90-6-724 Cell Bass/Midrange Driver. I don't see a lot of discussion about this driver yet. But it looks like the specs meet what I'm looking for. The extended frequency response gives me a lot of options. I might need to find a shop with a CNC to cut the precise hole in the baffle for the unusual mounting.

The final build will be a satellite over bass enclosure. Probably with two 10" Accuton woofers.