Mark Seaton 2x Submersive HP vs 1x Terraform XL

[Beatmatcher247]

I've been looking at what's available in aesthetically pleasing, high performance subs that are both musical and can throw down hard, and low, with lots of impact during movies. This has lead me to a choice between the 2 of the Seaton Submersive Hp's or one of the Terraform XLs.

2 is always better for taking care of LF response issues because you have the flexibility of moving the two until you have even coverage and uniform response across the band?

Anything else I should be looking at? Space isn't something I'm real concerned about.

I've heard Velodyne Minnivee series, SVS ultra 16 dsp cylinder or whatever it is, and wasn't all that impressed. Minnivee's output was quite impressive for it's size but I'm not trying to save space so it's not for me.

I was looking at do-it-yourself and it sounded pretty tempting but I just don't think I can match the quality of the finished product that I'm seeing in Mark Seatons builds. Any of you had experience with either of these products?

If you had $4,000 to go towards one or two subwoofers, what would you pick?

This is the last item I've yet to decide on my system and you guys have all been a huge help to me so far. I greatly appreciate all of your inputs. I'll put up some pictures and measurements when it all gets here and has been broken in .

 

[shadyJ]

Last I heard, mark wasn't selling those Terraform subs yet. Someone here inquired about them, and Mark said they were just not available. But if you want to know the right answer to your question, the best person to ask is Seaton himself, so give him a call.

By the way, for $4k I would go for a Hsu ULS-15 quad drive, or maybe something from Rythmik or Elemental Designs. Two ED A7s-650s would blaze pretty hard, and if you are really unconcerned about weight or space, get two A7-900s.

 

[cantonguy]

I would go with 2 submersive subs if I had that kind of cash to throw around. I think they are the best looking subwoofers out there. I love my Rythmik, but I'd drop it in a heartbeat for a submersive. Unless we're talking 4 F15's to 2 submersives...

 

[Brahms]

And between 2 Rythmik F15HP and a submersive HP, which one would be the smart choice?

 

[shadyJ]

The Rythmiks would certainly have more output, plus all the other advantages of multiple subs. My only concern with them is the strange behavior of it's limiter as described in Paul's audioholics review. If that can be addressed, than I would go for the Rythmiks without hesitation.

 

[cantonguy]

2 Rythmiks.

ShadyJ, I don't think the limiter thing is really an issue. As he stated the issue was with test tones and movies and music may not replicate it. Even if it were an issue...the limiter can be turned off. I never have the limiter turned on ever.
This would be an interesting question for Brian.

 

[KEW]

The Rythmiks would certainly have more output, plus all the other advantages of multiple subs. My only concern with them is the strange behavior of it's limiter as described in Paul's audioholics review. If that can be addressed, than I would go for the Rythmiks without hesitation.

You might be getting the model numbers mixed up - it is easy to do since the model numbers are not especially intuitive.
F15HP is a sealed sub. FV15HP is the sub reviewed by Paul in the shootout.

 

[Brahms]

The Rythmiks would certainly have more output, plus all the other advantages of multiple subs. My only concern with them is the strange behavior of it's limiter as described in Paul's audioholics review. If that can be addressed, than I would go for the Rythmiks without hesitation.

2 Rythmiks at 600W each to have more output than a single 2400W? how is that??

 

[GranteedEV]

2 Rythmiks.

ShadyJ, I don't think the limiter thing is really an issue. As he stated the issue was with test tones and movies and music may not replicate it.

Huh?

He stated that "sometimes it felt like the speaker would go from really quiet to REALLY loud unnaturally", pointing out that the limiter effects were present in listening tests.

 

[cantonguy]

Huh?

He stated that "sometimes it felt like the speaker would go from really quiet to REALLY loud unnaturally", pointing out that the limiter effects were present in listening tests.

"Huh?" what? Did you miss this part or am I missing something?

The limiter in FV15HP is defeatable. However, I had chosen to test the subwoofer with limiter ON. The curves with limiter off should be smoother and without this short hold time issue I noted. As for this hold time duration issue, it is a design trade-off. Shorter hold time can recover fast and provides more output over the same period of time. On the other hand, my preference is to have longer hold time duration as I stated above. I tested the H600PEQ amplifier with my review unit which engaged the limiter with the power switch set to "auto". Since that time, the amp has been updated to the H600PEQ2 model with a discrete on/off switch for the limiter.

 

[shadyJ]

2 Rythmiks at 600W each to have more output than a single 2400W? how is that??

My mistake, I thought he was talking about the FV15HP, not the F15HP. The Submersive should have more output than two F15HPs.

 

[Rythmik]

Huh?

He stated that "sometimes it felt like the speaker would go from really quiet to REALLY loud unnaturally", pointing out that the limiter effects were present in listening tests.

I am not trying to discredit what Paul (the reviewer) has done. But if you read between the lines, when is the last time you have to constantly turn the (subwoofer) volume up and down depending on playback material? It is when you have poor integration and when there is a phase anomaly at the crossover. And that experience can be easily mixed up with what limiter is doing. When limiter comes in, it means the amp is already already close to clipping. What can we do? We can either turn on the limiter and compress the waveform or just let it clips. After we compress the waveform, when do we let it recover? All these are limiter-related issues. Either way has its ups and downs with limiter or without. Furthermore, Paul test everything with 2ch. What type of music you get the amp to clip? Even Ethan and Adam tested the smaller version of FV15, it just let the limiter to be off. They can hear the sign of constraint when you play at SPL test level. But the sound is just as fast. Anyway, I'd like the fact that there are multiple people review the products and different angle and perspective is always good.

 

[Rythmik]

My mistake, I thought he was talking about the FV15HP, not the F15HP. The Submersive should have more output than two F15HPs.

To compare, you really need to look at the enclosure volume. Submerssive has two drivers sharing one common cavity space. Each one of them got only half of the space. It will be less than what the driver gets in F15HP. Enclosure volume affects efficiency. What is why our F25 is so big because I tried to maintain the same cavity space per driver when we move from F15 to F25. In addition, our power numbers are very conservative. One can compare what ours (600WRMS) got with what SVS 800WRMS sub got in AH shootout. Anyway, when it comes to spec, there is a lot of playing game out there. Some justify it with test conditions. So it is hard to fault anyone. A lot of time the max output is just dependent on raw excursion. Some may say 2200W is a lot more than 1200W, but to really take advantage of that, you need 40% more excursion. Anyone who plays with F15HP would know our transient excursion can be close to 40mm peak to peak at transient (and 30mm is common for steady state). Our mechanical exursion limit is 55mm in order to ensure no bottoming is possible. To get 40% more, that is close to 56mm peak to peak and mechanical exursion limit needs to be in then range of 75mm?? That is not a trivial increase. To see how much cone moves, just put a what dot on the black cone. If the driver cannot make that of excursion, the only way to get the excursion within control is to make the enclosure smaller (or spider less compliant).

 

[GranteedEV]

t

I am not trying to discredit what Paul (the reviewer) has done. But if you read between the lines, when is the last time you have to constantly turn the volume up and down depending on playback material? It is when you have poor integration and when there is a phase anomaly at the crossover. And that experience can be easily mixed up with what limiter is doing. When limiter comes in, it means the amp is already already close to clipping. What can we do? We can either turn on the limiter and compress the waveform or just let it clips. After we compress the waveform, when do we let it recover? All these are limiter-related issues. Either way has its ups and downs with limiter or without. Furthermore, Paul test everything with 2ch. What type of music you get the amp to clip? Even Ethan and Adam tested the smaller version of FV15, it just let the limiter to be off. They can hear the sign of constraint when you play at SPL test level. But the sound is just as fast. Anyway, I'd like the fact that there are multiple people review the products and different angle and perspective is always good.

Phase problem, didnt seem so as he was describing it.

Either way, agreed. I think at the end of the day it is tough, maybe impossible to hit a price point while making a sub that functions flawlessly at high outputs and low frequencies in larger rooms. Cost/size no Object is not realistic.

My comment was merely responding to the suggestion that this limitor situation was not a real world scenario.

 

[Rythmik]

t

Phase problem, didnt seem so as he was describing it.

What i meant as phasing problem is the phase is not perfectly aligned at the crossover point. We write an essay of 3 pages to explain it. When the phase is not aligned, there is a huge dip at the crossover point, if the playback material is mainly around that frequnecy point, one tends to turn up sub volume to compensate for it. Now when the playback material changes and hits a much lower frequency point, he needs to turn the volume down again. That is a common scenario of see-saw the volume control.

 

[GranteedEV]

What i meant as phasing problem is the phase is not perfectly aligned at the crossover point. We write an essay of 3 pages to explain it. When the phase is not aligned, there is a huge dip at the crossover point, if the playback material is mainly around that frequnecy point, one tends to turn up sub volume to compensate for it. Now when the playback material changes and hits a much lower frequency point, he needs to turn the volume down again. That is a common scenario of see-saw the volume control.

I understand what you're saying, and I can attest to the concept as an out of phase woofer sounds pretty uncomfortable, and someone might try to compensate for the crossover null with "more output". BUt, returning to his actual statement:

Now it could be argued that music does not have any sweeping tones that range across more than a decade (400 to 40 Hz is one decade) and last 14 seconds in length. They would be quite correct. However, I cannot help but relate this to instances where I was listening to music and the output seemed to suddenly jump out as if the volume control was being rotated without any help from my fingers.

it just doesn't strike me as an out-of-phase woofer.

 

[cantonguy]

t


My comment was merely responding to the suggestion that this limitor situation was not a real world scenario.

It really isn't a real world scenario. He was using test tones at very high volumes.

if he can replicate the "issue" with music or movies within the subs limits I'll take notice.

 

[GranteedEV]

Um, I JUST quoted him on exactly that:

instances where I was listening to music and the output seemed to suddenly jump out as if the volume control was being rotated without any help from my fingers.

 

[Rythmik]

There is no point of using large font size bold-face. What does that mean? I told you the reason and you seem to believe what the reviewer said than I said. Is it because he has more authority? Or is it becuase he designed our subs? As a minimal, has the reviewer included his in-room response in the review? You as an experienced audiophile relies on your hearing to do the integration? I won't do that. Show me the in-room response is what I asked. No FR, everything is just guessing, isn't it?

 

[GranteedEV]

There is no point of using large font size bold-face. What does that mean?

He was suggesting that the review stated this was merely a measurement anomally and would never show up in real world testing. I simply said that the review implied otherwise.

I told you the reason and you seem to believe what the reviewer says than I said.

You told me your conjecture on what you assume happened, and he stated his conjecture on correlation between measurements and what he had heard happening.

Neither is certain. But what you're explaining does not jive what what he was describing.

Is it because he has more authority? Or is it becuase he designed our sub?

It's neither. I never even suggested that most people would even drive the sub to the point of hitting the limiter.

As a minimal, has the reviewer include his in-room response in the review yet?

No. You're right, there's many, many factors that could have contributed to what the reviewer was hearing subjectively. But the statement that "the limiter behaviour was only a test scenario and the review supported this" is not true. The review suggested the POSSIBILITY of an otherwise scenario.

You as an experienced audiophile relies on your hearing to do the integration? I won't do that.

I certainly could not hope my ears can hear the intricacies of phase, especially not with a variable dial, well enough to do the integration. I too would use measurements. I was merely pointing out that I agree with you that an out of phase woofer can sound odd to say the least.

Show me the response is what I asked. No FR, everything is just what we guess.

I agree with you 100%. "just what we guess". I don't even have anything negative to say about your product, so I don't get why you're arguing with me.

I don't agree with this:

As [the reviewer] stated the issue was with test tones and movies and music may not replicate it.

Simply that the review did suggest that an otherwise case may have occured. That's my only argument.