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HT/1205 MKII Product Overview

Plays 50% Louder. Looks Like a Million Bucks

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The text below is a transcription of the video

Hi, good morning and thank you for joining us. My name is John Hunter, I’m the lead designer for REL acoustics, and I’m here to walk you through the new HT 1205, MKII, which is a beast. I’m kind of kicking myself for not having nicknamed this thing ‘The Hammer’. This is a 500 watt and a beast of a 500 watt amplifier, driving a 12 inch, completely new only for this application driver. It’s intended to really transform the affordable home theater world, and at the same time, for the first time, really be able to dig in and do great duty underneath high efficiency speakers in a music context as well. The goal of this is really simple. With the original HT, we had a piece that we wanted to really define as purely home theater, and they were actually really well received by music reviewers as well, the people who did speaker reviews and things and said, hey, these actually sound good for music. And they did. But in this one we went overboard making sure they were vastly better for theater. And I’ll get into that in just a second. And also much better for music.

So here we have a piece that’s really moderate in price at 849. It’s well under a thousand dollars. The output is prodigious. Most subwoofers in the sort of sub thousand dollars range, all cluster at a peak output of around maybe 102, 104 DB, somewhere in that range. This is about 6 DB hotter output than that. And that was not an easy task to get that under just a 500 watt amplifier. So very loud, punchier, more dynamic, and also more subtle. On the delicate stuff, you have to be able to render that perfectly.

It does better decay patterns, meaning dying into an echo. We really worked on all the hard to-do stuff for a subwoofer. So the driver is a brand new piece. I have a dear friend, Eric, that I work with. Every great company has to have, we jokingly call them driver wants. We have to have people on staff who live, eat, sleep, breathe, driver technology, and we’re always out looking for better pieces. This, for example, uses Taiwanese sourced lead-in tinsel wire from the connectors, the easy connectors on the back. Why are we doing that? They’re like three times more expensive than anything else that we would use on a home theater woofer. They’re that much more flexible and stronger. So they’re supple. They can keep up with this tremendous travel that we’re asking this driver to do. The driver itself, the cone is a black glass fiber. The primary cone, which is this area around the outside that you see, it continues on all the way across. And then we use a pure carbon fiber center cap that stiffens it tremendously, but adds almost no mass. So the driver is very reactive. It reacts to things very quickly and spontaneously with tremendous strength. So you don’t wind up getting that sort of warping cupping thing that if you really hit a driver hard and you do that in explosions and things, the special effects in theater. So we really bulked up on this one, but kept the weight low. Huge surround on this piece that was custom molded just for this piece. Everything we did was new on this and we shifted our suppliers. Just a side note, we really felt like we needed to go to our tier one suppliers, the best in the business and get them to work on this. In two years, this predecessor to this went from zero to our best-selling unit in the entire REL universe. So this is a really important piece for us. Alright, so the driver can handle a 500 watts easily, actually can handle about 600 continuous, but we leave a little bit of reserve in there. Everything is better glued down. The suspension pieces are bigger, stiffer but lighter. And that was really the key to this and you’ll hear it the moment you fire this guy up.

So the amplifier, we’re dressing this thing up a little bit, but ultimately it’s very simple in terms of its input block where on the traditional RELs you’ve got speak ons, you’ve got a zillion different things. It’s really simply left and right ends and left and right outs. Why left and right? I mentioned there are gonna be people that want to use these as pure music subwoofers. So really important to realize, and there we’ve got some tricks we’ll show you on separate videos later on how you can do both music and the 0.1 simultaneous out up one piece without any tricks. Well, no gimmicks, tricks for sure. Tremendous amount of range to the gain of this piece, which allows you to go from low efficiency speakers to high efficiency speakers. We expanded that matching range by about 3 DB. It makes all the difference in the world.

We did very different things in the filters. So what we found really quickly is that when you’re doing explosions, there are two components to our, one found an old friend of mine who was a Hollywood sound engineer back 25, 30 years ago, and he walked me through it. He said the hardest thing on an explosion is the initial crack. Once you get the crack, you get that boom that follows right behind it. Milliseconds behind. It’s the crack that kills the mics. They just overload like crazy. And we worked really hard and had special techniques to capture that. Once you get that, the boom is relatively easy, which is true. Everybody focuses on the bigness of the boom, but if you don’t get the crack, it doesn’t make you blink. So with these, what we wind up doing is taking our secondary filters. Those are the really gentle filters that are a few octaves beyond our primary crossover that we use to get rid of things like violins and sopranos coming through a subwoofer.

And we pushed it out so we could get that explosive quality. Explosions have dozens of octaves, they go on up to 40 or 50,000 cycles, but we need to be able to get that initial crack, right? So push that up about 150 hertz above where the normal one is and it just allowed all the energy to come through. Then we did our perfect filter. These are things that we developed for the TXs and perfect filter basically lifts all the frequencies in the low base uniformly. So you get this nice, really deep base happening. And then once we realized, oh boy, we got really strong deep base on this thing down at like 24 hertz and it’s gonna keep going¸ it’s not gonna stop. We can run into trouble if we go too deep and too loud. So I implemented an old trick from my analog days where I was designing Phono cartridges and we put a really subtle analog subsonic filter in at about five hertz.

And you go five hertz, you’re up at 24, what are you doing? It just goes up and it takes out the stuff up to about 15, 16 hertz that would just drive a driver crazy and cause destruction problems in the field. And the net result is we have this perfect combination where you have very flat, deep base and when it starts to get into that infra base region, it just quietly goes away and you don’t have to worry about that step down at 12 and 13 hertz the blows up drivers. It’s the best combination we’ve ever heard and it’s one of the reasons that we can push this thing so hard and get so much output out of it. These things are functionally limitless. They’re so loud and so effortless and they’re also composed. So to do all this, we had to do the cabinet, stiffen everything up.

You can see that all of the materials. Can you see this beautiful horizontal line graining on that? I’m just gonna slowly turn this. You can see the light catch it. It’s incredible. We want horizontal because I realize that when we use a really good composite like this, if we go vertical, like on the other one, the eye doesn’t see it the same way it does on an amplifier. Amplifiers are always line grade. So you have the look of a big $3,000-5,000 amplifier and it saves tremendously on cost because if you start doing individual painting of multiple coats, will immediately drive this piece well above a thousand dollars. But we got almost to the end and I went, oh, it’s just not pretty enough. So we increased the thickness of this and just gave it a really nice gravitas. It’s just so beautifully done. We have the REL logo. I’m just gonna tilt it just a little bit so you can see it, but it’s so subtle. It just almost sinks into the paint. When you look at, it looks sublimated inside the paint itself.

So one of the beautiful things about this design, this was not an accident. We really evolved this intentionally. See these beautiful vertical radii. They exactly match the radii on our Serie TX. And it allows this to work harmoniously in a system. It maybe is a much more evolved advanced system where you’ve got, for example, a center channel subwoofer for supporting $2,000-3,000 center channel in a big system and somebody’s dropped, for example, a T9X and does a huge amount to open up the entire center of the system. About 80% at any given moment can come through the center channel. And when you don’t have truly full range down into the twenties, that center channel actually can sound like Donald Duck quacking. It’s a really funny experience when the left right mains are supported by subwoofers, which they often are.

So we advocate for having full range center channels and all of a sudden, we’ve created something where there’s just a perfect harmonious blend back and forth between these new MKII HTs and an absolute dead ringer for the TXs, right down to the color of and the shape of the feet. You’ve got these dark silver feet down here that exactly mimic what we use on the TXs. They’re beautiful. There’s actually solid mineral filled nylon. They’re really well done. And that ability to harmonize back and forth between TX or even Serie S, which is very similar to the aesthetic as well. And these new HTs allows us to just open up ultra-high performance to systems that might have started off as a high end two channel system evolved into having some theater applications. Now you’re ready to take it to a whole another level.

We’ll show you pictures of this separately, but inside we have what we jokingly call our magic brace. It’s not a joke, it’s the real deal. So it’s not uncommon for people to use what’s called a window pane brace inside a subwoofer. Cheap subwoofers have them and they get it wrong. They always do it behind the driver. And if your driver is properly designed, you have this massive vent that goes right through the magnet and allows fresh cold air to come into the area where the voice coil is moving, it gets hot and it also reduces back pressure, right? If you’ve got a driver slamming back and forth a couple of inches, not only does it build up heat, but that’s a huge amount of air to evacuate. So we use really large exit ports. Then if you put a window pane brace behind it, the cool part of a window pane brace is that it sort of damps all four walls right at the top, the bottom, the left and right sides.

And that’s why they use it. It’s inexpensive and it doesn’t, we use a massive version of it and we use it totally differently. Our braces are about two inches, maybe bigger, maybe 60 millimeters, and two and a half inches wide. So you have a lot more mass, but we don’t put them behind the driver because when we’re doing development, when you put a window paint brace back behind it, you can hear it. That jet of air hits that and it splatters and you can hear it coming right back through the driver if there are no speakers on. So we make this large one, we drill a large hole that actually holds and cups the entire magnet assembly and we line the inside of that with felt. So now you have a piece that actually supports the driver during shipment. So if it takes a shot, the magnet doesn’t do something like buckle the frame, you quiet the back of the thing.

So you’re damping resonances and the exit port is allowed to shoot all the way back to the back of a chamber just like it should be. So it’s a really well thought out comprehensive and yet still very inexpensive way to get all the walls of the cabinet damped much better than the standard, you know, one inch window pane brace and also support the driver and allow that exit port, that vent in the back to just express all the way back to the back of the chamber. It’s one of the example of how we think of things a little different, where we see what people are trying to do and go, okay, that’s a great idea. It’s just terrible execution. And we work hard to come up with innovative solutions that don’t add a lot to the cost. Do a whole bunch for the product.


April 19, 2023 - Posted in: Videos