Need help deciding on waveguide MT or TMM

[Martinsson]

Hi,

I am about to embark on my first speaker build so please bear with me when I ask what to some are very basic questions. I have read up a lot on this and other forums but I still have a couple of questions specific to my installation. The waveguides of John Marsh and John Krutke design intrigue me, so that is the way I have decided to go. However, I am unsure of the following:

1) Can these speakers be built sealed? I will build dual opposing 18" subwoofers that are flat up to about 200 Hz according to WinISD. Thus, I can have the Xover for the waveguides set between 80-120Hz. If I can go sealed, can I reduce the cabinet volume (without changing the baffle) and still use the recommended Xovers? If possible, I would like to build the speakers as small as possible.

2) Are there other benefits to going TMM vs MT, other than better SPL and lower distortion? Jon has included a Xover for a possible future WGTMM in the PDF for the Modula MT XE design. It seems as the Xover design for WTMMs is not definite however, any suggestions on what tweaks might be necessary?

3) On a subjective note; if anyone has listened to both the Modula MT EX and the Zaph WGTMM, how would you describe the difference in sound? I realize this is a very difficult thing to do but I have been unable to find but a few build threads and listening impressions of any these two speakers.

I am grateful for any input. Thanks for a great forum! I have already learnt very much by just going through old threads. Your craftsmanship and knowledge is truly inspiring.

Best regards Martinsson

[Martinsson]

Maybe the projects is already dead in its inception...

OK, not many responses to my questions. I did some further research today and I am unable to find the MCM H-65 Threaded Horn Lens used by both John and Jon. They seem to have gone out of production. Is there a suitable replacement for the H-65?

Perhaps this is the reason why I can´t find many of the Modula Xtreme out there?

Cheers Martinsson

[Hunter12]

You should have a look at this. No wave guide to mill.
Dennis Murphy is one serious heavy weight in this small world,
do some research. You will notice the cost is very similar
to the NatP speaker but you are using Norwegian built
woofers instead of Asian.

http://forums.audioholics.com/forums/showthread.php?t=68531

[dar47]

Hi,

I am about to embark on my first speaker build so please bear with me when I ask what to some are very basic questions. I have read up a lot on this and other forums but I still have a couple of questions specific to my installation. The waveguides of John Marsh and John Krutke design intrigue me, so that is the way I have decided to go. However, I am unsure of the following:

1) Can these speakers be built sealed? I will build dual opposing 18" subwoofers that are flat up to about 200 Hz according to WinISD. Thus, I can have the Xover for the waveguides set between 80-120Hz. If I can go sealed, can I reduce the cabinet volume (without changing the baffle) and still use the recommended Xovers? If possible, I would like to build the speakers as small as possible.

2) Are there other benefits to going TMM vs MT, other than better SPL and lower distortion? Jon has included a Xover for a possible future WGTMM in the PDF for the Modula MT XE design. It seems as the Xover design for WTMMs is not definite however, any suggestions on what tweaks might be necessary?

3) On a subjective note; if anyone has listened to both the Modula MT EX and the Zaph WGTMM, how would you describe the difference in sound? I realize this is a very difficult thing to do but I have been unable to find but a few build threads and listening impressions of any these two speakers.

I am grateful for any input. Thanks for a great forum! I have already learnt very much by just going through old threads. Your craftsmanship and knowledge is truly inspiring.

Best regards Martinsson

I have not heard Zaph's wave guide design but I have built his L18's and can attest to his great designs. I didn't see the H-65 on their site but I would contact them for availability.
The other option is to create your own waveguide with the baffle.

I built ported and integrated a 10" sub crossed at 50hrz and they work vary well with a little eq. They do go lower out of their class because of cabinet size but that is a good thing.

You didn't describe what your using these for, theater, 2 channel, what kind of room their going in?

These speaks do vary well both on and off axes, check his response curves. The wave guide provides better woof tweet integration meaning they sound like a vary good 3 way. I built these for music in a great room and needed good walk around sound but love sitting in front of them and they sound way better in my treated room. Need another set or maybe the extremes? Nah bet their not that much better.
Check jon's PDF out for impressions I was smiling after playing the L18's next to the MT's as I felt he gave a very good description of the sound.

Jon has squeezed all you can out of these drivers and I can't imagine this combo sounding any better. The nice part is they do well with poor material and will not limit sound with good material and electronics. He has chosen low distortion parts and built the best sounding xover I have heard. Lots of designs coming out with these drivers for a reason? For me after listening to them for 8 months I am still smiling and consider them the best discovery and investment I have made in sound reproduction in 30 years.

[JonMarsh]

OK, not many responses to my questions. I did some further research today and I am unable to find the MCM H-65 Threaded Horn Lens used by both John and Jon. They seem to have gone out of production. Is there a suitable replacement for the H-65?

Perhaps this is the reason why I can´t find many of the Modula Xtreme out there?

Cheers Martinsson

Boy, don't you just hate that? I do... it seems you're right about the H-65. I have a few, and there are somewhat similar parts available for drivers, but not really the same for tweeter adaptations.

For the Modula Extreme, I've got several pair of Jantzen waveguides in house to try out with various tweeters, the most promising being the Ciare MT320.




Image not available

Both had to be sourced from Europe. For a "high end" system I don't think that's so bad, but for something like a moderate price two way, a better cost solution is needed. Haven't found one yet.

The Jantzen waveguide is VERY high grade BMC, very stiff and inert; I have high hopes for this combo. But haven't tested it yet- work is a real CF this year so far, and I haven't had a day off on the weekend since January. We have open unfilled hiring reqs... and I'm basically covering two different jobs in different areas.

I'm also sitting on crossover updates to test for the Ardents with the existing ER18RNX woofers, and new Scanspeak woofers to try out. Very frustrating year so far personally for audio, other than getting a decent bedroom system going with a digital doc for my iPad that feeds an DAC which feeds powered speakers (Audioengine A5n, in bamboo, of course) .

[Martinsson]

Waveguides and tweeter combos

Jon,

Thanks for your reply. I notice that Troel Gravesen uses the Audax TW034XO-P47N with the Jantzen waveguide. Can that be an option for the Modula MT EX too? I guess you don´t believe in combining the Jantzen waveguide with the original ScanSpeak D2608-9130? Parts Express have waveguides too but they look quite different from Jantzen's or MCM's.

Can I please ask you to comment on my question about making the Modula MT EX sealed and reduced in depth for my setup, while keeping the original baffle?

I listen 70% to music and the rest is HT, to answer an earlier question. The room is quite spacious and I like the idea of a large sweet spot.

I hope work clears up a bit for you and brings more balance to your life!

Cheers Martinsson

[Martinsson]

0,5 cuft sealed as Xtreme?

Hi Jon,

I looked over your Xtreme thread again and it occurred to me that you built a 0,5 cuft sealed 2 way that matches my needs, as the top speaker for your Xtreme version. The Accuton driver is just too expensive for me as my first DIY project. Could a possible compromise combination for a less costly speaker be:

Seas ER18RNX and ScanSpeak D2608-9130 or Ciare MT 320 with a Jantzen waveguide in the sealed 0,5 cuft enclosure?

I guess it would require a completely new crossover compared to the Accuton/Scanspeak D26008/9130/MCM waveguide you devised for the Xtreme speaker. I do not know too much about crossover design as you can tell but I hope to learn through my DIY project.

Is the Jantzen very different from the MCM in curvature? I am asking since diameter and depth seems to be identical between the two.

Cheers Martinsson

[TW1]

Hi Martinsson I built these sealed over the summer, basically they are about 14-liter cabinet. They sound excellent and are run with a sub, very forgiving to room placement. I can give you the cabinet dimensions if you’re interested. As far as the wave-guide is concerned do a search on Polypro PH65 there are still some available .Buy one or two extra, I would not wait if you are serious about theses.

http://www.allaudioexpo.com/i/pylepro_ph65_screw-on_type_constant_ra.html

[Martinsson]

Interested - YES!

Hi TW1,

Thanks for your reply. I am very interested in the dimensions of your sealed Modula MT XT speakers. I assume you kept the original baffle size and reduced the depth of the speaker?

Can you upload picutres of your speakers? That would be awesome!

Thanks also for pointing me to a waveguide.

Cheers Martinsson

[TW1]

The outside dimensions are 10x17 for the baffle no change ,their 8 7/8" for the depth.
I will try to get some pictures in the next couple days with inside dimensions,have not upload pictures before but I will give it a try.

[Martinsson]

Smaller cabinet?

Thanks for the dimensions TW1! Very helpful. I hope you can publish a photo or two, would be much appreciated!


I went though the original Modula MT XE thread again and I found your discussion with Jon. I must have been reading through this thread ten times and yet I missed it! :roll:

Do I understand correctly that Jon also declared that the PE 0.5 cuft cabinet would be OK? It has a smaller baffle and it is what he uses for the Modula Xtreme TM. I thought a smaller baffle would require changes to the crossover?

I am a little pressed for space and prefer smaller enclosure. But I do not want to compromise away the good sound qualities of Jon's design.

[JonMarsh]

The main tricky point to manage is the baffle size and at what point you want to cross your sealed Modula MT MkII's over to a sub. The T/S parameters of the ER18RNX are such that sealed in the original box, they will have a lean sounding bass- but should be usable with a sub at 80 Hz or higher. The smaller box (0.5 cu ft) will actually be better, because it will bump up the Qts of the system a bit; the ER18RNX is over damped for a sealed alignment in the original box.

The link TW1 provided looks like the right part- if you're not up for doing your own waveguide in baffle as dar47 did, I'd jump on those. In fact, I'll wait a small decent interval for you to order yours, then I'll probably order a pair or two also.

The Jantzen waveguide has too large an opening to work with the Scanspeak tweeter- the throat matching is quite important.

I have some of the Audax TW034 to try out, too, but as Troels notes, it does have an internal resonance. Troel's plan for modifying the rear magnet assembly can deal with that, but it is some substantial work and time- which is why I was looking for other candidates like the Ciare MT320 with more modern motor structures and hopefully lower distortion and even better performance.

[Martinsson]

TW1 and Jon - thanks for your support!

I can cross over at 80-120 Hz from what I have modeled in WinISD for the sub.

Jon, for my understanding, is the original baffle Modula MT XE, with an enclosure reduced to 0.5 cu ft the way to go, just as TW1 did, or do you mean that it is better to use the smaller baffle in the PE 0.5 cu ft enclosures (as in your Modula Xtreme MT module)?

I can probably do my own waveguide in the baffle but I would like to have one of the MCM's or Pyle Pro's to make sure I get an identical throat anyway and I don´t mind a plastic waveguide to begin with!

Cheers Martinsson

[JonMarsh]

If you're willing to reduce the depth and keep the same size baffle as the original, I'd recommend that. another point to consider is fitting the crossover in the enclosure- that will be harder to do with the 0.5 cu ft PE enclosure.

If you have a router table, milling down the waveguide after cutting off the threaded insert is pretty straight forward to do- let me know if you have any unanswered questions re the PDF and forum posts.

[TW1]

I made the back of the cabinet removable because of the crossovers as Jon points out. The other option wood be to make the cabinet a little longer and have a separate compartment for the crossovers kind of like what Lunchmoney did with the Black Bird Center maybe Jon can comment. Also I ordered some of the Pyle wave-guides ,they should be delivered in a week or so and I will compare them to the MCMs.

[JonMarsh]

TW1, will be curious to see what you report; I expect they're OEM'd by one company, resold by several. I should place a couple pair on order this weekend, too, just for NOS. (New Old Stock). The combination with the SS tweeter is a real honey, in my opinion.

[Martinsson]

I search for the waveguides on the Internet and I came up with at least one, perhaps it was two, sources who treated them as being the same, i.e. MCM H-65 (Pyle Pro PH65). They seem to be the same product, which would make sense.

Here is one link: http://www.diyaudio.com/forums/multi...e-now-aus.html

And this is the data that Altronics provides for it:

Standard 1” threaded round flare.
Cutout dimension (mm): 133mm
Flare dimensions (mm): 166Ø

[Winter]

Martinsson,

You have a PM.

[Martinsson]

Thanks Winter!

Jon and TW1, I will go with the original size baffle and reduce the depth of the cabinet. Thanks for your support and explanations. I will report back once I got the project going.

TW1, I still hope to see photos of your creation!

Can somebody help explain to me how I can paste a picture in my post, as Jon did with the Jantzen waveguide above? I thought I would post a picture showing my design of the subwoofer cabinet.

Cheers Martinsson

[JonMarsh]

If your picture is under 100kB, you can do it from your PC. You need to be in normal Reply mode, not quick reply- scroll down to the Additional options section, attach files, and attach the file to your response. Click on the attachment link from the pop up window to open the picture in another window, then copy the address of that window, and use it with the picture icon in the toolbar above where you enter text in the normal reply window, as I've just done below.



Or, as I do much of the time, you can use your own file hosting service and upload pictures to that, then link to them using the picture icon for embedding an image.

[Martinsson]

Jon, thanks for the instructions! It was the linking thing I couldn´t quite figure out.

I have posted a picture of my design of a combined media center/ subwoofer/center speaker. It is two opposing ED 190V2 subwoofers enclosed by the media center. I chose the ED190v2 because they are fairly flat up to above 100Hz and quite musical according to reviews. I sacrificed some real low end punch, below 10Hz, for musicality.



The center speaker is one of Jed K's excellent design, the Clearwave Dynamic 4CC SE. Jon's Modula MT XE will be the fronts in this set up and I think they will integrate nicely with the 4CC SE, which has the same tweeter as the Modula. The 4CC will be sealed as well. Jed has spent time working with me to ensure that the design works as intended. He has really come through to help, just as Jon and TW1 did.

My rear satellites are Mirage OMD-5, which I chose mainly because they ominpolar and because they mount well up on the wall where it meets the ceiling.

I have provided two plots for the ED190V2, one sourced from ED data and one from a guy at Hometheratershack, who is known by the name of NeoDan. He claims to have measured the ED190V2 and come up with different data than the manufacturer. Anyway, both plots align well with my target.



Cheers Martinsson

[Jed]

The center speaker is one of Jay K's excellent design, the Dynamic 4CC SE.

Cheers Martinsson

That's Jed K... not to be confused with Jay K.

[Martinsson]

But of course, Jed K it is! ops: Apologies for any confusion. Anyway, thanks for your excellent support Jed!

Cheers Martinsson

[Jed]

But of course, Jed K it is! ops: Apologies for any confusion. Anyway, thanks for your excellent support Jed!

Cheers Martinsson

No problem... your kit is on the way. Just packed up the last bits today (the wire).

Jed

[Martinsson]

Thanks Jed. I got two other parcels from FedEx yesterday so the kit is soon complete.

Cheers Martinsson

[TW1]

Received the Pyle ph65 today and are the same as the MCM.The inside cabinet dimensions are 15.375x8.5x6.875 deep.14.7liters ,subtract bracing ,driver ,crossover volume close to 14 liters.Did take some pictures will try to post them.Looking at the sub center I wonder if this speaker is a good match?Maybe the Dynamic 1S SE would be a better match and could be built sealed.

[Jed]

Received the Pyle ph65 today and are the same as the MCM.The inside cabinet dimensions are 15.375x8.5x6.875 deep.14.7liters ,subtract bracing ,driver ,crossover volume close to 14 liters.Did take some pictures will try to post them.Looking at the sub center I wonder if this speaker is a good match?Maybe the Dynamic 1S SE would be a better match and could be built sealed.

I'm confused, but to answer your question at the end there, the Dynamics can be built sealed with a much higher f3 point than ported.

[Martinsson]

TW1, thanks for the confirmation on the waveguides. Mine are somewhere in the shipping process still. Thanks too for the measurements of your inner cabinet. I hope to see some photos of your. They will be a good inspiration.

I spoke with Jed before I decided on the Clearwave 4CC and Modula MT XT combination. In Jed's assessment, integration between the two should be fairly seamless. I want to do Jon's waveguide to try something different and because his MT XE will work nicely for 2-channel music. I also look forward to assembling the crossovers myself. I built large parts of our new house by myself and now I am ready for new craft work challenges, albeit a challenge better scoped than a house! Speakers fit the bill perfectly.

The subwoofer SPL is ridiculously high according to WinISD-simulations but that is because I fed WinISD with max output from the amp. I like to have ample amp headroom to reduce distortion and also to exercise detailed control over the huge woofers. I never listen to music or HT at those levels though.

I have felt a heavy gravity pull towards Jon's Ardent thread lately... This is a dangerous forum! In the future, I need new speakers for my pure 2-channel system in the living room too.

Cheers Martinsson

[Martinsson]

Jed, I got the last shipment from you this week. I will open and relish over the weekend. Thanks for all support!

Martinssin

[Jed]

Jed, I got the last shipment from you this week. I will open and relish over the weekend. Thanks for all support!

Martinssin

Happy building!