Transferring thread to new forum…
@traw - saw your chat question looking for the 2026 InDIYana theme thread. This is it. My thread on the 2026 Indy theme (linked below) was just a test thread that I started to see if the forum was working. OK to post Indy theme stuff on either thread, but if you have any questions about the theme rules they should probably go on this thread.
Blurry ass photo from dark sans flash. Now to glue on ‘holders’, using 3/4 strips of plywood to glue n clamp to left right middle baffle opening. Made self a pilot hole template to hopefully repeat mount holes - any recommendations as know number of yall (like versabox and others) for re-usable cabinets?
Thinking 4 mounts, but maybe 6 better. Box will be ported and ‘mid’ baffle section will have speaker gasket around outter edge. Also intending 2 ports, behind each woofer though know maybe better to have them not directly behind (midrange leakage), especially if try a combo where reaching to low 1k’s with the epics though think will remain 800hz and lower. But really hope end up with a finished speaker.
Secondary question… Was originally planning to use 2 faitalpro fe35’s, though the 1 set have brutal hacked up mount tabs and visualizing rear mounting on mid baffle creating headaches of ignorance, like put 45 chamfer - so started thinking if go clean with diff pair of mids but still in the pro audio near full ranger’s (3-4inch). Was eyeballing beyma 3FR30V2, new to be in stock soon at PE. Though they are 3 inchers, ~88-90db and know if gonna drag them into 200-250 low xover point some bsc, inexperience has gut wondering if enough snap in that 200-500 hz range from pair of 3’s. Where sometimes wonder if extended range 5 inch single 200-4k better blend.
Hah - know few have tried diy cone slicing, no surround slicing and tacky gluing heh? I notice sooo many 4 incher’s end up with a dip somewhere 1.5 to mid 2k’s which guessing often from the cone of that size surround resonance or diffraction artifacts. Aware experienced person knows how look beyond that, off axis as well. Recall that was one non crucial thing that noticed with SB12CAC, butter smooth on axis in that 1-2k (maybe deal with baffle 1k bump) unlike many 4’s, with no special surround treatment (or pro audio like accordian/cloth surround)
I recommend 6 bolts to mount, as 1.5” MDF will bow in the middle without the middle 2. However, I’m thinking of adding 2 more bolt options. Why? Because then you can have swappable tweeter baffle and swappable woofer (mid) baffle as well. It keeps your options further opened.
When I first read this, I thought the challenge is to make a 3 way where it is the same driver for every way!
That’d be an idea. Pick a wide band driver and split it up into a three way!
Was assuming I would need to measure each mid driver individually, but is it viable to measure them together as a pair?
Being lazy not wanting to run extra wire heh, but also wonder if would capture the overall diffraction pattern better. Though imagine a learning opportunity to measure both ways to observe differences. Measurements will be at 1m, typically get about 4.4ms gating window in garage and CTC of these 3 inchers about 6.5 inch. Sure I manufactured some oddities with the top/bottom lip to woofer sections.
I always measure the M’s in a MTM wired together as one “driver” and as they will be used (i.e. in series together or in parallel). I do the same thing for the woofers in a WMTMW project. I’ve never done a MTMWW (3.5 way) project before, but if I did I would still measure the mids as one driver. I would, however, measure the woofers as individual drivers since they would be receiving different signals. Hope what I typed makes sense.
What Craig said.
Is that an MTM, then yes, you need to measure both drivers together.
- Measure on the Tweeter axis - i usually do at 1M
- Measure the tweeter first
- Then wire the Mids as you want, most probably in Parallel if they are both 8 ohm for a combined nominal of 4 ohm
- Measure both the mids - for the calculating the accoustical center of the Mids, the X and Y will be the same, since the center of both the mids is the center of the tweeter. You need ot then figure out z which is how deep the accoustical center of the mids are - will be slightly behind the tweeter
- Then measure the Woofer
- Then measure all three - Tweet, both mids and woofer.
- For the woofer, also take a nearfield and blend with the farfield
Why is this a 3.5 way? If you are doing 3 way, then measure the woofers together, if 3.5 way then separately. But where are you looking for the XO points?
I don’t believe he ever said it would be a 3.5 way. I was only pointing out that if it was I would treat the woofers as two different drivers with separate measurements. From his picture I would measure it as a simple 3 way with the two mids wired together as a single driver, and the two woofers wired together as a single driver. Then you can take as many off axis measurents as your heart desires or your s/w crutch requires. Hey… that rhymes! ;-p
1 Like
Gonna be 3 way, mids are https://www.parts-express.com/Beyma-3FR30V2-3-Full-Range-Loudspeaker-8-Ohm-253-091?quantity=1 . Using peerless dx20 3/4” tweet, recycled from prev build. Xover points prob 300/4800. Guess assemble first one with all wires coming out to do various measurements.
Sometimes I use backwards way for determining offsets where put some rough offsets in, get xover simulated for first iteration then measure rev nulls where see how db deep the null is and use that to fine tune offsets so simulation matches. Though I think will try to proper way with all wired in parallel and look at impulses (i think, heh)
Maybe spin own thread off, but i suck at documenting/photo-ing - too much adhd surge heh. Got my 1st iteration of mtm for Indy26 readied. Awaiting hole sealing glue to dry. Figured put a speak on connector on back and not gonna bother running individual wires for each mid, run as a ‘system’. Bummed I f’d up the measurements on the darker lighted one on the right where see one mid close to tweet than other - meh, see if I have enough curiosity to measure difference in overall assembly of baffle.
EDIT - adding image of one assembled. Dark gray primer, figure out color later. Speak-on on back of cab for the mids paralleled and tweet, then wires hanging out ports on back for woofers. Likely install binding post and wire up woofers in so can tinker with port tuning easier later. Yeah doubt see any measurement diff, think it will be more if visually nags me.
2 Likes
Unlikely there will be much measurable differences.
Think I prob need to scrap/sideline my approach. Took 0-60 measurements, nearfield etc. Simulated, wired up, adjusted and just seems my pair of beyma 3 incher’s just ended up with a much better sounding speaker using a 450-550 xover woofer to mid vs 300-350 to fit into the challenge- live n learn. Well aware that it is the challenge but then I question myself is it really a problem i need to solve given already have a viable solution for what used, thus I chose wrongly IMO. Already using 4500-5500 mid-high xover and given the beyma 3 like a fullranger, need to pull that mid high rolloff hard/steeper via 3rd order electrical. Think I just park it in the basement and maybe revisit with a conventional single 4-5 inch mid and tweet when time to. But of course as I type this, other things to try pop into my head heh, just rough when feel like already have an answer and bzzzrrr, out of bounds. Did learn things and affirm some previous lessons though.
Cross at 7k, the mid should be good till there oand higher. If you are not happy with the off axis, bring down the XO after the event.
Ah, actually in simulation seems feasible - break out the 0.05 coil heh. Prob stuck in head how not enough tweet interaction but was more result of voicing to get the right sound from subtle slope of the mid in passband. Though starts to feel like indy 25 and a super tweeter, though i think the real challenge then was for the full ranger not to excessively distort from low freq/imd. Think i was venting frustration.
EDIT/Addendum: Knew was frustrated, moaning about constraints. Today swapped the epic7’s in since felt like didnt wanna sink the spendy seas drivers into the project. But it turns out the epique’s much more friendly to 2nd order electrical and think titan7 woofers were humping up, steeper roll off thus wanting 4-600 hz, from the 3rd order electrical so now get away with 330hz woof-mid xover with epic’s. Then what was saying answer own question, given the beyma full ranger ish have no natural rolloff to assist crossover, so went with 4th order electrical rolloff from mid to tweet (still 3rd order on tweet) and gives me the flexibility to adjust that crossover point easily. Plus seems steep rolloffs not as offensive or fiddly when up there around 5k, more level matching and phase match easier. Typically on woofer to mid blending prefer lower order electrical for more natural sounding, shared blending. Now these things are cranking and crisp, go loud as f*** with no strain. Though running them off a crown xls since 3 ohm from 80-300hz. Also able to tune box little lower, less humping from coil size, think need to reduce a little from 3 to 2.7 but hard to tell in small room, yet. But happy with the near end result, big sound. Need to take to a bigger room to re-affirm voicing.
1 Like