Any subjective opinions on the Seas DXT?

[DoubleTap]

Just wondering if anybody with ears and experience enough to tell differences has used the Seas DXT, and if so what did you think of them? I have a pair in the basement, just trying to decide whether to use them or not ... application I'm thinking of would be a 2-way bookshelf with a Scan 15W, using a 1st order network crossed in the 2500-2800hz range.

[mzisserson]

Just wondering if anybody with ears and experience enough to tell differences has used the Seas DXT, and if so what did you think of them? I have a pair in the basement, just trying to decide whether to use them or not ... application I'm thinking of would be a 2-way bookshelf with a Scan 15W, using a 1st order network crossed in the 2500-2800hz range.

Subjectively: Out of the 50+ seas drivers I have herd over the years in various configurations. NONE of them I have ever fell in love with, or would own. Some sounded very nice, but they all sound like seas, which to me is slightly brazen.

I believe your money is better spent on Scan. Again 100% IMO.

[critofur]

I recently shipped some RS28F tweeters to a fellow DIYer in Ukraine who compared them to his Scan Speak tweeters. He likes the RS28F better.

I do have a pair of Seas DXT tweeters, I just don't get around to finishing projects :( I also have recently gotten ER18RNX woofers, so I might just try MarkK's ER18DXTs for an intersting listen...

[Pete Schumacher ®]

Just wondering if anybody with ears and experience enough to tell differences has used the Seas DXT, and if so what did you think of them? I have a pair in the basement, just trying to decide whether to use them or not ... application I'm thinking of would be a 2-way bookshelf with a Scan 15W, using a 1st order network crossed in the 2500-2800hz range.

http://www.audioheuristics.org/projects_gallery/ER18DXT/ER18DXT.htm

[DoubleTap]

http://www.audioheuristics.org/projects_gallery/ER18DXT/ER18DXT.htm

I know Pete, I'm looking for subjective "how does it sound" opinions. There's no shortage of great performing tweeters, most are in my basement right now :D I'm just totally indecisive on which to invest my time into creating a finished design.

[Zilch]

Mark's DXT was "Best of Show" at NorCal DIY last year.

It's constant directivity; I'm upgrading Dynaco A-25 with them in the next "Flex Your PCD Mettle" project.

If diffraction, the very operating principle of DXT's waveguide, is a massive HOM generator, I'm not hearing it.... :rolleyes:

[Face]

.....

[benchtester]

Just wondering if anybody with ears and experience enough to tell differences has used the Seas DXT, and if so what did you think of them? I have a pair in the basement, just trying to decide whether to use them or not ... application I'm thinking of would be a 2-way bookshelf with a Scan 15W, using a 1st order network crossed in the 2500-2800hz range.


Basically, I like the DXT. Although the faceplate is standard size, it's response definitely shows the waveguide hump. With a simple crossover it can become a nice LR2, but I ended up with a low 2 khz. crossover point. Non-waveguide tweeters are probably more flexible in adjusting the crossover point. The DXT waveguide is reasonably effective for improving off-axis response.

Other tweeters you might consider are the Scan Speak Discovery HDS. I am working on a 15W/HDS combo now, but I won't have any listening impressions for a few weeks.

The Scan Speak AirCirc D3004/6600 is very nice but at a much higher cost. For roughly half the price, is the ScanSpeak D2004, which also has good reviews.

If you check my blogs (upper right in my avatar line), you can see my frequency response curves for a 15W/6600 combo and a Zaph 14/DXT combo.

EDIT BTW: to actually answer your question. The DXT is should be easy to mate to the 15w (we're talking Revelator?) I think the DXT sounds pretty good, better than most, and worthy of the project. However you should tweak the DXT to make the best LR2 curve and then it will be easy to match the 15W to where the tweeter wants to be. It should be a good speaker. Higher priced tweeters will offer a small improvement (maybe an upgrade path in the future); if you want speakers to enjoy, go with the DXT and don't worry about it. If you want speakers that will stand up to extreme critical listening scrutiny, then maybe you might consider the other tweeters.

[MSaturn]

I bet it sounds like a tweeter!

[Wolf]

Ryan- I liked what I have heard from it. I heard it in the "Trilliums" Paul Ebert had at InDIYana last year, and the "Shrubbery" that Scott Sehlin brought to Iowa.

Sound- super-clean and balanced. Not a lot of 'air', and depending on application, it can have a rather low sensitivity.

Nothing jumped out at me in terms of peaks or anything, and it's a good sound. It's just not as sweet as an Air-Circ.

My 2c,
Wolf

[Paul Ebert]

As Wolf mentioned, I used them in my Trilliums. I like them a lot, but I haven't had much experience with other tweeters, so I can't make much of a comparison. The only other tweeters I've heard much in a long-term setting (as in, owned) are the RS28A (in my pair of Module MTs) and the tweeter in the ProAc Tablettes.

I would agree that it may well lack a bit of air, since once you deal with the waveguide hump, the top octave sags a bit. I went with it because I thought the off-axis response (which is quite impressive, IMO, and based on Zaph's measurements) would be a good match to the RS52 at the crossover point chosen. I think I accomplished that.

I also hoped for improved low-end distortion with the crossover in place (as Zaph documents in his experiment with the D26 in a waveguide), but I can't really say that subjectively I've noticed that effect. It sounds quite clean and natural to me, but I'm not sure I'd say it's better then the RS28A in that regard.

Assuming you mean an electrical 1st order, you would probably be fine, though you may find that it takes a little more shaping. I do not think you can get an acoustic 1st order due to it's intrinsic response, but then, that's just a hunch.

All that said, the HDS would certainly be awesome with the 15W as would, I am sure, the air circ. I would love to get a chance to work with either of those.

[scottsehlin]

Agree with the above. In my "Shrubbery" project, they sounded very clean and were well-behaved - but lacked a little air. I crossed at 2kHz with LR4 acoustic slope and it was pretty easy to get the upper mid/lower treble right - but the tweeter response curve definitely preferred a specific shape, that led to a little top end rolloff. The in-room response was very smooth - which I attributed to the DXT waveguide.

[dlr]

I know Pete, I'm looking for subjective "how does it sound" opinions. There's no shortage of great performing tweeters, most are in my basement right now :D I'm just totally indecisive on which to invest my time into creating a finished design.
I have had a pair since I bought them for experiment. Kept finding others to work with. I now have them in a transitional 3-way with the SS 15W/4531G currently on top of a SS 25W/8565-01. This is a dipole system for woofer and mid with a single DXT in monopole. I hope soon to have a pair of Peerless 10" dipoles under each M/T. But at least I've got something of the flavor of how it will be.

This system will, I hope, be auditioned at DIY NE this year, so there should be feedback from others soon. Mark (mark65) was able to drop by for a visit and had the opportunity to give me some feedback and seemed to like that system in some ways better than my Peerless 10"-12m/4631-OW1 system. I suspect that is more due to the dipole midrange and woofer.

I don't yet have a long-term assessment. Part of my problem is that I think that it's influenced as much by the dipole mid vs. monopole tweeter arrangement. I selected the DXT for several reasons (other than actually having them on-hand :cool:).

First, it eliminated the need I usually feel to offset the midrange. The DXT appears to be sufficiently recessed that I thought it unnecessary.

Second, I hoped to use a smallish baffle that makes it harder in some ways to control diffraction since felt placement is limited. I was surprised to see that some significant diffraction remained until I studied where it occurred. A small baffle had created a diffraction signature that began somewhere slightly above the DXT raw turning point, since that is a transition area of the tweeter itself. The DXT has a strong 2-pi response, but it does become 4-pi of course. Baffle dimensions will come into play, but are a bit less predictable. The output at 90 degrees is not like typical domes that are the basis for most diffraction software. It did complicate what I started trying to do passively. I was looking for about a 2K Fc for what I thought might match well with the 15W. My baffle is likely smaller than a closed box system may need. I also did not want to offset, further complicating it.

Third, I hoped to work a crossover that smoothly transitioned from dipole to monopole and that had reasonably controlled directivity (the DXT isn't constant directivity). As Mark K showed, the response off-axis can be very good. I have not yet made a full set of off-axis measurements, so I can't say how successful I've been.

I can say that so far I like the sound. It does seem a bit more limited in the top octave, but compared to an OW1 3-way or even my older, tweaked SS9300 3-way, that isn't surprising. I suspect it's more likely the directionality coming into play than the actual top end extension. It certainly seems to stay very clean without any harshness when pushed. I still think that more of my impression is coming from the 15W midrange than what the tweeter is doing.

The top end sensitivity does drop, but I don't have that as a problem :D. I'm using SoundEasy v17 with its Ultimate Equalizer. A 3-way is a snap, even with dipole EQ. It can easily compensate for sensitivity differences while making crossover "design" a snap. It really makes the emphasis on driver selection and associated crossover integration points more the issue. As benchtester pointed out, the DXT directivity that exaggerates the peaking at the highpass makes passive crossover Fc selection a lot more difficult. I had started casually playing with Jeff's PCD and quickly realized that what I wanted to do probably didn't have an easy passive approach. Add in the dipole EQ and I went straight to SE.

I know that this is more than "what it sounds like" and limited on that aspect, but I thought it might prove helpful.

dlr

[Pete Schumacher ®]

I know Pete, I'm looking for subjective "how does it sound" opinions. There's no shortage of great performing tweeters, most are in my basement right now :D I'm just totally indecisive on which to invest my time into creating a finished design.

He showed those at a DIY event a while back. There were quite a few thoughts about them posted on the board. Figured you might search the threads for mention of it.