Hi Matt, I'm adding the second MBM 15's to my Titans like Mike and Jarod. Initially I'll be paralleling them with the existing 15's. Can you tell me what mod I need to make to the crossover? Also, in about a month I will be Bi-Amping them like Mike, will there be any additional change I need to make to the crossover when Bi-Amping them? Thanks
A 4uF cap should be placed in parallel with the 18uF cap (or replace it with a 22uF cap). A 10 Ohm resistor placed in parallel with the 6 Ohm resistor (or replace it with a 4 Ohm resistor). Finally remove or cut a lead from the 33 ohm resistor. The second woofer should just be wired in parallel with the first woofer to the crossover board. Unfortunately all the setup I did to Mike's speakers with the active Bi-amping was done in his room and as such they have EQ and filter settings that were largely influenced by the room itself. So those setting won't be suitable for others. I haven't done any true testing myself on the dual woofer version since I only have one woofer and enclosure. The passive approach has only been simulated and I offer that only as an optional untested modification. I don't like the idea of releasing active filter settings on simulation alone so I don't plan on releasing those settings until I can actually measure the speaker and make sure it actually sounds like it should.
Hi Matt, Are there FRD and ZMA files available for the Titan-615 LX drivers? Especially for the Mid and Tweet as mounted on the dual horn. I've been playing with XSim 3D and want to try bi-amping or tri-amping my Titans. Any data on the LX woofer and/or FRD and ZMA files on the woofer? I converted graphs from Eminence and Celestion for the mid and tweet, but that doesn't reflect response and impedance when mounted on the dual horn. XSim is a very nice program. I have been playing with it a bit by using your crossover component values and comparing your mod updates with original. I like the change to the mid and tweet. I lowered the tweet using DSP in my amp instead of adding the 27 ohm resistor. Since I cross fire the left and right front, I lowered the center a bit more to give similar voicing. I could have decreased the center less and not lowered the left and right front, but, the setup is working well as is. Thanks
Hi Paul, My FRD files are kind of a mess for this design and won't be good to tinker with since they don't really accurately reflect the whole response of the speaker.
Thanks Matt. I'll keep plugging away and see what I come up with. Looking forward to any updates from you. The Titan-615 LX was a very enjoyable project. I could leave it alone and be happy. But, I like to play and learn more. Thanks again.
Hi Matt I am just putting together my new Titans and I am just wondering ... for dampening you recommend "(~2" thick foam, polyfill, fiberglass or recycled denim)". Would you also consider 2" of OC703 ... OR a couple layers of 1" Quiet R Rotary Duct Liner better options ... or would they actually hinder performance? Thanks Dean
Thank Matt I think I will just get some foam then ... I don't want to take a chance on hindering performance. Regards Dean
Can you guys please post or send me the TS specs for the custom Em 15? Email is fine as well. I'd like to model it in various enclosures and applications. Thanks! At very minimum, curious about Xmax, Xmech, Mms? Fs?
See http://www.hificircuit.com/community/threads/eminence-15-subwoofer-and-midbass-information.5463/ or https://www.diysoundgroup.com/speaker-parts/speaker-components/woofers/buyout-15-sub.html
Hi Matt, I'm looking at the crossover mods, and I'm curious if adding the resistor in parallel with the HF outputs will greatly affect the overall impedance? Thanks, Grant
No significant change in overall system impedance (<0.5 Ohms) at the top end with that resistor added. Now the more recent crossovers have had the 33 ohm resistor eliminated and a HF resistor value changed (to 20 Ohms instead of 15) so that those optional modifications (slightly increased midrange level/slightly decreased HF level) are now built into the stock crossover. That said a resistor can still be added across the HF output terminals if you wish to further decrease the output of the high frequencies.
Got it - thank you! I went with the finished crossover option when I bought my (2nd!) Titan kit, which was back in April of ‘18, so my guess without opening it up at the moment is that the crossover is of the older variety.
Hi Matt, I bought my Titans back in December, finally making some headway with the build, I have many questions, first, to make them bi-amp-able, should I isolate just the tweeter, or put the tweeter with the mid-range, I'm thinking that in the future I might want power the top end with a tube amp, maybe a Primaluna. Second, do you think it makes sense to add adjustable L-pads to the tweeter and or the mid, or would that kill the sound quality? Third, would turning the horn upside down screw up the FR response? I was looking to lower the tweeter to closer to ear height. I know these might be stupid questions, but, I am hoping these are going to be my forever speakers, am using a Brytson 4B for an amp, 325 watts at 6 ohms, should be plenty loud. Kent
If you want to make them bi-amp-able I'd put the tweeter separately from the woofer and midrange since those two driver and the range they cover require the most power. If you do this you will have to completely separate the crossover network for the high frequency driver as the PCB uses a common ground or negative connection. Adding an L-pad between the tweeter and the crossover does not modify the response, so no issue there. An L-pad on the midrange does change the response some mainly reducing output near the crossover to the HF driver, but it's not terrible especially if the padding amount is kept low. No harm in trying the horn upside down but it does narrow the dispersion around the midrange/woofer crossover range due to the greater CTC distance. If the HF driver is not too far above ear level I suggest just tilting the waveguide downwards slightly to aim it correctly rather then flipping it over.
Hi Matt, thanks for getting back to me, I am working on a way to make the tweeter and mid tilt down a little, it's going to be adjustable, I'm going to cut the uprights vertically, about 1-1/2" from the front edge, round the bottom front, place a carriage bolt at the bottom, and add a piece of wood near the top on the inside, with a curved slot in it, with a carriage bolt and knob, it doesn't need to tilt very far to aim it at my ears with a twelve foot listening position. I'll recess the bolt heads and hide them with Bondo. I decided to double the front baffle, as well as the the other five. I've also added a "T" shaped brace behind the woofer, and a 2-1/4" x 3/4" brace from the top to the bottom. I know this is probably over kill, but i figured it couldn't hurt. I'll be posting pics on the Facebook forum DIYSoundGroup Enthusiasts. Kent
In regards to the 630 modification,most people are flipping the bottom cabinet for the second woofer and stacking it on top of the assembly above the wave guide. Is there a preferred distance between the 2 woofers in this design? Will placing them too close or too far apart cause them to interfere with each other?
Hi Matt, I think for now I’m only going to put a L-pad on the tweeter, I bought an Eminence 100w adjustable pad, and I am putting a 20a DPDT switch to bypass it if it’s not needed. I also figured out how I’m going to separate the HF circuit on the cross over board, it’s really not going to be that hard, if I had thought ahead, I might have not ordered the completed cross over, but they are really, really nice. I found a really good place to mount them, right between the ports, I added a piece of bracing in the bottom and they will sitting vertically, parallel to the ports, in between them. I’m getting excited now, the end is in sight! Thanks for your help, Kent
I am doing this optional modification and I realized after getting my parts I choose a 10 watt 4 Ohm resistor to replace the 25 Watt 6Ohm. Do I need to purchase a larger 4Ohm resistor? It looks like there is a 20W available at PE. Is this large enough? I know these titans can handle a lot of power and I don't want to burn up the crossover. Also, I am attempting to take measurements of these modifications outside and will post them when I am done in case this might help you understand how these work in the real world.
10W will be fine if running the speaker around AVR power or a little higher. The 20w is what is used normally for extra headroom.
In an attempt to learn more about my speakers and also help you understand what these modifications are doing, I have done some testing outside during the build process to understand what these modifications do to the response. Hopefully this helps you as well. These tests were done across 3 different days so they are not the most scientific however they were done outside in the country so there should be minimal reflections and low noise. The first test was done facing an open barn about 50 feet away. This was late at night and I was in a hurry so I didn't have time to move them further away. Behind the speaker was nothing but open field. Titan 630 Stock crossover. Here is a measurement with just the 33 ohm resistor removed. The speaker still sounded boomy to me. I don't like the rise in frequency start too far above 100Hz. I hadn't received my other crossover components yet so I did some playing around with EQ in the inuke and I settled on the following: PEQ 200Hz +4db Q1.9 I felt this gave the best response of everything and had a very nice measurement as well. If I ever have the ability to to eq each channel individually, this is probably what I would use unless the impedance drops too low without the other modifications. Finally, here is the measurement with all the modifications suggested. The 33 Ohm resistor was removed, a 4uF cap was placed in parallel with the 18uF cap, and the 6 Ohm resistor was replaced with a 4Ohm. I didn't make any modifications to the top end as I don't find these to be too bright. I am coming from the Fusion 12's which I find were even brighter still so these already sound more neutral. This was also probably my best measurement. This was done with the speaker facing the field and the house about 100ft behind the speaker. Midrange response isn't quite as smooth as it was with just the EQ. I would also like to see more boost in the 200HZ range to push the rise closer to 100Hz. And to give you an idea of the conditions for the final measurement, here are the photos. Hopefully I got it right because I probably won't be lugging them back up stairs and outside again any time soon. Let me know if you would like to see anything else or if you would like a copy of the MDAT. I can send you a link if you would. Hope this helps!
Thanks for taking the time to measure it. It's not too far off what I would have expected. The modeled design was done trying to get away with minimal modifications to the original crossover. If an official dual woofer titan design ever get released it will have a crossover designed specifically for that model. The dip near 200-300hz range is due to the stock inductor being slightly too large a value for the lower impedance load provided by the second woofer, a smaller inductor value there would decrease the peak ~75hz and fill in the 200-300hz range. I think the differences you are seeing in the midrange could be differences in the mic or speaker position/distance especially as the measurements appear to be unrated and you will be picking up some ground bounce reflections.
Hopefully if a dual woofer design is ever released with a better crossover design those of us who made the jump early will be able to get it as well. As for the inductor, how much smaller would be required? I'd be willing to try a couple if you have an idea of a better value for it. Right now I'm using the curve editor in audyssey to shape the curve toward where I like it. Finally, I'm not sure what you mean when you say my measurements appear to be unrated. Could you explain that please. If I do this again in the future, I want to make them as accurate as possible. Of course, it would be better to do them all at the same time under the same conditions, however, that wasn't possible this time. If I make any future modifications, it should be possible to take them all at the same time.
I'd try a 2.5mH inductor instead of the 4.0mH and add a 50uf NPE capcitor to the unused LF C2 position (if you have the PCB) otherwise tie it in parallel with the 100uF capacitor. That will add about 3dB of boost centered around 200Hz. Unrated was a typo, ungated is what I meant to say and gating the measurements can be applied to the existing mdat files. Gating or windowing limits the time interval that REW uses to calculate the frequency response. Using a shortened time window to can limit the data to include only the direct sound energy from the speaker and effectively filter out any reflected sound. The downside is that the shorter the time window them more you will filter out and loose resolution at low frequencies. This is why you may often see speakers being measured up on tall stands or ladders (or sometimes lifted with cranes) to get it further from any boundaries and allows for a larger time window which will results in a wider usable frequency bandwidth. The Titan doesn't lend itself to being easily lifted up on a tall stand or ladder so that makes it harder to get accurate measurements. One of the methods I do use is taking many measurements with the microphone at different distances and averaging them which can help filter out the effects of those reflections.