I'm newbie in this stuff but I'm sure that this would be the super easy way 😀...but what horizontal off axis response and horizontal lobing?
It's still going to be better than a lot of MTM designs that people use as center channels.
You could move the woofer closer to the tweeter. Moving a driver location on a baffle will most likely have some effect on the frequency response, but, in this case, that effect will probably be less significant than the changes you will get from placing a speaker under a TV in a TV stand.
Ideally, if your TV is mounted high enough: place the speaker vertically and on a stand at least a foot in front of the wall/any large furniture.
I'm not able to check vertical response of the er18dxt using praxis but this looks quite good no dip in fr...
An externally hosted image should be here but it was not working when we last tested it.
Im thinking of building this speaker but would it have any benefits of building it open baffle for the woofer and tweeter and using an active x-over at 239Hz for a sealed 15" subwoofer for more low frequency response.
Can't help you with the open baffle thing, but I build mine sealed. I put them into a 12l enclosure, baffle dimensions as in the original design. Should give a Qtc of ~ 0.65 and f3 around 80hz. I choose that because my speakers are close to the back wall. I run a Ripole subwoofer with them and I am very pleased with the result.
Does any body know the circuit for a 200Hz active crossover that does not use any opamps or add distortion.
It's been a couple years since this design came out, are there any new MT's that best this design in the price range or does this still reign supreme?
azimut,
Did you try it horizontally as a center channel? I'm guessing it worked well...
Did you try it horizontally as a center channel? I'm guessing it worked well...
I haven't heard of any comparison where people prefered another speaker over this one, regardless of price range... As always, there will be some matter of personal preference and any given listener may prefer various other similar/higher/lower priced designs...
Have you had a chance to measure them? What sort of stuffing did you use? Are you using them with an "active" high pass filter (built in to your receiver perhaps?).
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Some ER18RNX measurements:
#1 Fs 44.9; Qe .38; Qm 1.44; Vas 35.45
#2 Fs 46.24; Qe .35; Qm 1.33; Vas 37.48
I've put this pair in a couple of 38L boxes & relegated them to bass duty in my bi-amped system for few weeks to break in;
The final system will be similar to Mark K's, but I'll be using the metal cone Seas Tweeters (27TBFC), undecided as yet but may go for a wide baffle design (~450mm)...
#1 Fs 44.9; Qe .38; Qm 1.44; Vas 35.45
#2 Fs 46.24; Qe .35; Qm 1.33; Vas 37.48
I've put this pair in a couple of 38L boxes & relegated them to bass duty in my bi-amped system for few weeks to break in;
The final system will be similar to Mark K's, but I'll be using the metal cone Seas Tweeters (27TBFC), undecided as yet but may go for a wide baffle design (~450mm)...
a couple of hours & a couple of dopplebocks later --- hey, these things are d@mn good woofers!!!...
Hi all. Keen to build these boxes myself.
I have never previously built any cabinets but have access to the necessary tools and believe i can do it.
Can you tell me if im on the right track here.
I found on the Parts Express website the spec sheet for marks cabinet.
It shows detailed plans of the boxes, with all dimensions.
What i am considering is building them in 18mm MDF. with the same single brace through the centre. i think the brace was 12mm.
The change i will make from the plan is to build the more conventional DIY box with the baffle built in, not as they sell it with the removable baffle. Also im not shure how thick i should build my baffle? 25mm? 32mm?
Am i on track here? appreciate you thoughts.
I have never previously built any cabinets but have access to the necessary tools and believe i can do it.
Can you tell me if im on the right track here.
I found on the Parts Express website the spec sheet for marks cabinet.
It shows detailed plans of the boxes, with all dimensions.
What i am considering is building them in 18mm MDF. with the same single brace through the centre. i think the brace was 12mm.
The change i will make from the plan is to build the more conventional DIY box with the baffle built in, not as they sell it with the removable baffle. Also im not shure how thick i should build my baffle? 25mm? 32mm?
Am i on track here? appreciate you thoughts.
Just finished a pair of these last night in the curved PE boxes, I'll probably make a thread later as I need to open them up to glue in the ports and fasten down the crossover boards and I'll use the opportunity to take some pictures.
Really nice to these ears, I don't recall hearing a better speaker of this general type. (Those who've been around this hobby a bit will know remarks like this about a newly-built speaker should be immediately dismissed as biased rubbish, but there it is anyway 😉 ). Better bass than I expected, and the power response "magic" Mark alludes to with the combination of the DXT tweeter and low-order crossover is certainly in evidence as I walk around the room and try different seats. Very well integrated as well, no sense of individual drivers unless I stick my face right in there and listen for it.
Couple brief comment for anybody else who might be drawn to the sexy curved PE cabinets for these things:
- the back of the curved cabinet is not wide enough for the huge flared Precision Port. I found a suitable non-flared replacement from some random ebay sale and fitted the inner flare from the Precisions, you'll probably need to do something similar.
- plan out a robust way to fasten the crossover boards to the curved walls of the cabinet, the woofer board in particular is HEAVY and you shouldn't count on letting that big inductor rest on the bottom to support that weight as the woofer magnet almost can't get past the inductor in that position (and having that big magnet permanently slammed against the inductor can't be a good thing, I would think).
- the recommended stuffing (in a ported cabinet, no less) looks ridiculously excessive when you're doing it, but it seems to be working. At least try it, and try the big hunk of batting that obscures the port opening too before dismissing the whole scheme. My results may change as the woofers get burned in, and my current placement is a scant foot from the wall behind which probably fattens things up a bit, but I'm liking the bass balance so far with the cabinets well-stuffed.
Really nice to these ears, I don't recall hearing a better speaker of this general type. (Those who've been around this hobby a bit will know remarks like this about a newly-built speaker should be immediately dismissed as biased rubbish, but there it is anyway 😉 ). Better bass than I expected, and the power response "magic" Mark alludes to with the combination of the DXT tweeter and low-order crossover is certainly in evidence as I walk around the room and try different seats. Very well integrated as well, no sense of individual drivers unless I stick my face right in there and listen for it.
Couple brief comment for anybody else who might be drawn to the sexy curved PE cabinets for these things:
- the back of the curved cabinet is not wide enough for the huge flared Precision Port. I found a suitable non-flared replacement from some random ebay sale and fitted the inner flare from the Precisions, you'll probably need to do something similar.
- plan out a robust way to fasten the crossover boards to the curved walls of the cabinet, the woofer board in particular is HEAVY and you shouldn't count on letting that big inductor rest on the bottom to support that weight as the woofer magnet almost can't get past the inductor in that position (and having that big magnet permanently slammed against the inductor can't be a good thing, I would think).
- the recommended stuffing (in a ported cabinet, no less) looks ridiculously excessive when you're doing it, but it seems to be working. At least try it, and try the big hunk of batting that obscures the port opening too before dismissing the whole scheme. My results may change as the woofers get burned in, and my current placement is a scant foot from the wall behind which probably fattens things up a bit, but I'm liking the bass balance so far with the cabinets well-stuffed.
Ermat, as long as you keep the internal volume and the external width of the baffle the same, you'll have no problems.
re:'Better bass than I expected' - yep, it's really clean... I like weighty low end presence, I'm thinking a pair of these per side would make a really good 2.5 way system...
re:'Better bass than I expected' - yep, it's really clean... I like weighty low end presence, I'm thinking a pair of these per side would make a really good 2.5 way system...
I got your email but haven't had a chance to reply. As long as the baffle layout and internal volume are the same, you should be fine. You can extend the cabinet backwards slightly to keep the volume the same if you change the thickness of any panels. The PE cabinets are good, but it's possible to make even more inert cabinets if you're so inclined.
As far as the stuffing goes, yes, it looks funny. And it does taper the maximum bass output somewhat. You could use less stuffing, and get somewhat increase bass.
There is a downside to removing the polyfill. It really does absorb a lot of the midrange backwave that adds quite a bit of irregularity to the FR in the midrange. It doesn't show in the usual short window DIY measurement, but it's there nonetheless.
Here's a really old graph to show what I mean. It's a 10 year old measurement of an SS8554 that I did when I was still using clio. You can see the difference/point.
An externally hosted image should be here but it was not working when we last tested it.
after a couple of weeks using these as woofers, the only major change in parameters has been a drop of ~2Hz in Fs, maybe I'm not pounding them hard enough...or they're really well made....
Thank you for this great design, and this forum has been quite valuable to me already.
I Just ordered the parts and i am so looking forward to building them. The expenses were a bit higher then expected, though the expectations exceeded the expenses. I had to build them😉
When they are finished, anyone is welcome to have a listening session. Netherlands, Delft. Since that is never that easy diy audio.
all the best,
Bas
PS. As a reference, Ill attach my shopping list. Everything bought at europe-audio.nl. No shipping costs and they helped me out on buying the resistors (which wattage was needed).
_____________________________________________________
10 Dempingmateriaal 245x325x10.0mm 11.30
1 Dempingmateriaal wit voor 20 liter 2.31
2 Jantzen cross cap 15.0u 400V 6.80
2 Jantzen cross cap 5.10u 400V 3.86
2 Jantzen cross cap 5.60u 400V 4.38
2 Jantzen SUPERES 2.00 Ohm 1% 4.26
2 Jantzen SUPERES 2.40 Ohm 1% 4.26
2 Jantzen SUPERES 27.0 Ohm 1% 4.26
4 Jantzen SUPERES 3.60 Ohm 1% 8.52
2 Jantzen SUPERES 33.0 Ohm 1% 4.26
4 Jantzen Wire air coil 0,220mH 0,205Ohm 1,00mm 8.00
2 Jantzen Wire air coil 0,600mH 0,370Ohm 1,00mm 6.38
2 Jantzen Wire air coil 2,500mH 0,410Ohm 1,60mm 43.50
6 Luidspreker OFC kabel 2 x 4mm (per meter) 15.06
2 MKP polipropyleen folie condensator 3µF 250V 3.62
2 Monacor Luidspreker terminal met vergulde connectors* 13.10
2 Port tube ø 50 x 145 5.72
2 Seas 27TBCD/GB-DXT 1 inch tweeter high definition aluminium magnesium alloy dome 77.96
2 Seas ER18RNX 6,5’’ woofer 118.84
12% Super discount -12.94
Order totaal EUR*€ 398.00
I Just ordered the parts and i am so looking forward to building them. The expenses were a bit higher then expected, though the expectations exceeded the expenses. I had to build them😉
When they are finished, anyone is welcome to have a listening session. Netherlands, Delft. Since that is never that easy diy audio.
all the best,
Bas
PS. As a reference, Ill attach my shopping list. Everything bought at europe-audio.nl. No shipping costs and they helped me out on buying the resistors (which wattage was needed).
_____________________________________________________
10 Dempingmateriaal 245x325x10.0mm 11.30
1 Dempingmateriaal wit voor 20 liter 2.31
2 Jantzen cross cap 15.0u 400V 6.80
2 Jantzen cross cap 5.10u 400V 3.86
2 Jantzen cross cap 5.60u 400V 4.38
2 Jantzen SUPERES 2.00 Ohm 1% 4.26
2 Jantzen SUPERES 2.40 Ohm 1% 4.26
2 Jantzen SUPERES 27.0 Ohm 1% 4.26
4 Jantzen SUPERES 3.60 Ohm 1% 8.52
2 Jantzen SUPERES 33.0 Ohm 1% 4.26
4 Jantzen Wire air coil 0,220mH 0,205Ohm 1,00mm 8.00
2 Jantzen Wire air coil 0,600mH 0,370Ohm 1,00mm 6.38
2 Jantzen Wire air coil 2,500mH 0,410Ohm 1,60mm 43.50
6 Luidspreker OFC kabel 2 x 4mm (per meter) 15.06
2 MKP polipropyleen folie condensator 3µF 250V 3.62
2 Monacor Luidspreker terminal met vergulde connectors* 13.10
2 Port tube ø 50 x 145 5.72
2 Seas 27TBCD/GB-DXT 1 inch tweeter high definition aluminium magnesium alloy dome 77.96
2 Seas ER18RNX 6,5’’ woofer 118.84
12% Super discount -12.94
Order totaal EUR*€ 398.00
