Heissmann DXT-Mon-182

[Ktacos]

Can someone explain the phase issue here?

Is there an issue? Just looks like the phase of a two way with 2nd order filters.

 

[suttondesign]

that was what I was asking, whether it is troubling.

 

[suttondesign]

Update:
Applied a 4db boost at 2360hz with a Q of 2 (may change to 2.5, we'll see) to address the room-response dip there as shown below. Otherwise, subjectively a very smooth overall response and super-tight phantom center. Very good image depth. Decided to high-pass the Heissmann at 60hz with my two big subs low-passed at 50hz, still working on that exact handover. The Heissmann speakers sound subjectively very good down to 50hz, and I don't push to 96db so as to elicit distortion down low.

 

[Vuki]

Congratulations! Looks like very successful project.

 

[gingermellow]

@Vuki @suttondesign How do they perform in terms of spatial envelopment? Do they present a wide soundstage, or does the sound feel more like it’s coming from a single point in space?
I’m looking to upgrade from Yamaha HS8s, whose wide horizontal dispersion I really enjoy. I’ve tried a few pricier 5–6″ models with narrower dispersion; while I preferred their tonality, I couldn’t live with the more ‘pinpoint’ presentation.
From Heissmann’s directivity measurements, it looks like these sit somewhere between ‘wide’ and ‘narrow.’ Does that match your experience?
Also, would you describe their voicing as more on the warm or the bright side?
Thanks.

 

[Vuki]

I don't have DXT mon 182.

​

 

[suttondesign]

@Vuki @suttondesign How do they perform in terms of spatial envelopment? Do they present a wide soundstage, or does the sound feel more like it’s coming from a single point in space?
I’m looking to upgrade from Yamaha HS8s, whose wide horizontal dispersion I really enjoy. I’ve tried a few pricier 5–6″ models with narrower dispersion; while I preferred their tonality, I couldn’t live with the more ‘pinpoint’ presentation.
From Heissmann’s directivity measurements, it looks like these sit somewhere between ‘wide’ and ‘narrow.’ Does that match your experience?
Also, would you describe their voicing as more on the warm or the bright side?
Thanks.

hi there,
so, on studio recordings, my linkwitz dipoles spread out a human voice in a reverberant field. nice, but not like the actual recording. the heissmann sound like you are listening to the recording process in a good way, with a super nice, stable phantom center and excellent depth.

in my room, heissmann vocals are a bit behind the speaker plane and are velvety smooth. not dry, but certainly more on the studio monitor side than wide dispersion speakers. so, yes, a middle ground on horizontal dispersion. The stability of the phantom center is beguiling. the width of the stage is fine, I have no issue.

neither warm nor bright. smooth and balanced apart from known room modes below 200hz. that is why I like them as well as the linkwitz dipoles. it is also why heissmann compares them directly to the neumann kh 150. i will compare them to my son’s kh 120 and report back.

i like the heissmann better than the dutch 8c in some ways because I thought the dutch lower frequencies sounded unnatural even if the response was like butter. so I am saying that a $1750 build, not counting amps I already have, compares favorably with $13,000 actives.

 

[suttondesign]

Reporting back on these speakers, and with some additional thoughts on waveguides.

Still using the Heissmann passive outboard crossovers I built instead of trying to develop a DSP-based crossover in the MiniDSP flex8. When I have the Heissmann switched out and use the Linkwitz LX521, I miss the buttery smoothness and focused imaging of the Heissmann. Really beautiful. When I have the Heissmann switched back in again, I miss the transparency and spaciousness of the Linkwitz. Sigh.

I guess there's no right answer here as between dipoles and conventional box speakers (please, no blowback from the Linkwitz folks). But note that I spent less than $2,000 on the Heissmann, and could have spent a lot less had I used just Finnish birch plywood. And they only need 2 channels of amplification. Compare the Linkwitz at, what, $10,000 in drivers, woodwork, amps, DSP (or else a complex analog crossover) and SO MUCH setup time.

One thing that I think is truly remarkable is how ASR and a few other people/sites have driven a measurement-based approach. I note that the new Audio First Design
Cadentia 3, which is super exciting, has the same kind of beveled face (waveguide) as the Heissmann DXT-Mon speakers. And both Heissmann and other new mfrs. are also using the round (or round-ish) waveguides. Siegfried, likewise, did tons of measuring to develop his weird baffle shape for the LX521 based on directivity, and he noted how critical it is to build the speakers to tight tolerances with his baffle design.

What we're seeing, and is so interesting, is a convergence in design approach on smooth directivity transitioning at crossover frequencies, and it's a remarkable development that I certainly never saw coming. Combined with some new very high quality drivers with lower distortion than was previously readily available, and you can get a lot of bang for the buck from a box-type speaker. For decades, it was mainly OK drivers in boxes in lots of often silly, arbitrary variations with marketing hype. Of course you can get something that sounds decent that way, but you can just as easily get something very colored, too.

We know now that you can't fool the Klippel. I'm going to put in some overtime and build those Cadentias!

 

[Halbknapp]

The only complaint I have is that the DXT-Mon series was designed with a different batch of seas dxt tweeter and would need crossover rework.
"Applied a 4db boost at 2360hz with a Q of 2"
Yeah, I basically did the similar as suttondesign wrote but one should not have to.

 

[MT_bassbone]

Pretty much done. Haven't tested them yet. Waiting on finish to cure. A couple of cosmetic flaws. No one would mistake them for high-end factory-made, but they certainly do look hand-made, which is not nothing.

Great job on the build. What did the crossover parts cost? Did the metal bracing come from the hardware store?

 

[suttondesign]

Great job on the build. What did the crossover parts cost? Did the metal bracing come from the hardware store?

$378, plus I paid $25 for the plexiglass onto which I mounted the x-overs, and then about $30 for the Wago connectors.

And yes, the threaded rod and bolts came from an amazing local hardware store in Bellingham. The foil-faced rubber stuff lining the inside of the speaker deforms to keep the rods in place nicely with a friction fit without putting too much stress on the cabinet itself.

 

[Inertiaman]

The only complaint I have is that the DXT-Mon series was designed with a different batch of seas dxt tweeter and would need crossover rework.
"Applied a 4db boost at 2360hz with a Q of 2"
Yeah, I basically did the similar as suttondesign wrote but one should not have to.

Can you provide some additional insight w.r.t. potential DXT differences:
- is there a way to identify which "batch" DXT one is using?
- has Heissmann acknowledged this anomaly?
- is there a documented/known design change to adjust the crossover for a different DXT?
- does this issue carry through all his DXT designs (esp DXT-Mon-RNX)?

I am planning a DXT-Mon-182 build and have acquired the drivers and cabinet materials, but haven't yet acquired the crossover components. Hence I am curious/concerned if I should potentially implement any changes to the crossover based on your claims/observations w.r.t. the DXT production runs.

 

[MT_bassbone]

Can you provide some additional insight w.r.t. potential DXT differences:
- is there a way to identify which "batch" DXT one is using?
- has Heissmann acknowledged this anomaly?
- is there a documented/known design change to adjust the crossover for a different DXT?
- does this issue carry through all his DXT designs (esp DXT-Mon-RNX)?

I am planning a DXT-Mon-182 build and have acquired the drivers and cabinet materials, but haven't yet acquired the crossover components. Hence I am curious/concerned if I should potentially implement any changes to the crossover based on your claims/observations w.r.t. the DXT production runs.

I am building a pair of these right now. Curious about the replies.

 

[Halbknapp]

Can you provide some additional insight w.r.t. potential DXT differences:
- is there a way to identify which "batch" DXT one is using?
- has Heissmann acknowledged this anomaly?
- is there a documented/known design change to adjust the crossover for a different DXT?
- does this issue carry through all his DXT designs (esp DXT-Mon-RNX)?

As far as I know Heissmann has rather old DXT Tweeters. Even mine (3 pairs) are many years old. So anyway you would have much newer batches. I can't tell at what point the DXT tweeter was changed but if that was intentional from Seas it was done a long time ago.

I also have discussed that with Alexander Heissmann many years ago but we came to no conclusion. I adapted my own DXT-Mon for a more flat frequency response but did not do it for my DXT-Mon 182 as they now all run through a surround reciever with dirac that I use to correct the response anyway. In a pure stereo system I would probably correct the crossover. But rest assured that one or 2 simple EQs yield the same result.

It can be assumed that all of his dxt designes have the same dxt tweeter as base so all have the same anomaly when you build it. Still the solution should one Try to fix that would be individual for each speaker as is the tweeter crossover to begin with.

 

[Ktacos]

Can you provide some additional insight w.r.t. potential DXT differences:
- is there a way to identify which "batch" DXT one is using?
- has Heissmann acknowledged this anomaly?
- is there a documented/known design change to adjust the crossover for a different DXT?
- does this issue carry through all his DXT designs (esp DXT-Mon-RNX)?

I am planning a DXT-Mon-182 build and have acquired the drivers and cabinet materials, but haven't yet acquired the crossover components. Hence I am curious/concerned if I should potentially implement any changes to the crossover based on your claims/observations w.r.t. the DXT production runs.

AFAIK all the talk of tweeter batches is just total speculation by forum users. It all seems to be based on one persons build that was shared here. I'm not aware of revisions to the DXT aside from different dome materials that I think only Grimm is using. What is more likely the cause of the differences is issues with the builders analysis tools or measurement environment. We don't have all the info from the builder, like were they using a cal file for their measurements. My mic for instance shows a similar dip without it's cal file.

 

[Halbknapp]

AFAIK all the talk of tweeter batches is just total speculation by forum users. It all seems to be based on one persons build that was shared here. I'm not aware of revisions to the DXT aside from different dome materials that I think only Grimm is using. What is more likely the cause of the differences is issues with the builders analysis tools or measurement environment. We don't have all the info from the builder, like were they using a cal file for their measurements. My mic for instance shows a similar dip without it's cal file.

The first DXT-Mon (original smaller model) a former DIY Fellow built was exactly like the original. Mine and all other I have seen thereafter are different regarding tweeter response.

And if the response of several builders all over the world looks the same it's not a problem with their analysis tools. And regarding Heissmann, his other speakers like Cinetor or Cinetor Evo and Disco-m that some here locally have built match with his measurements top to bottom.

Make of that what you want but i got my conclusion what are remaining possible causes.