Ahem, $125,000 a pair for these.
Lordy.
I bought 4 subwoofers and I'm absolutely not doing a DBA! Hah!
I just received shipments of 4 subwoofer drivers and they will not be going into a distributed bass array.
I'm replacing my left and right speaker stands with powering subwoofers with 2 subwoofer drivers each. I call them powering because they will be powering the 2-way monitors that will sit on top. Here's a beauty shot of the insides.
The amp has all the DSP power I could need to produce perfect speaker measurements. I wonder if JA at Stereophile would wax poetically if I priced them high enough?? 
Showing 19 responses by erik_squires
Reading the comments about amps I think the average reader doesn't unerstand that the amps I'm using are 3 channels of amplification plus digital signal processing. While similar to the average subwoofer amp you'll find screwed onto the back of all active subwoofers the Hypex multi channel amplifiers do not have simple controls. There's no knob to set the low pass or high pass or volume. Everyth8ing is done by the crossover designer (me) with their application. In essence if you can imagine a miniDSP EQ and crossover plus several amplifiers built into a device that shares a single power cord you will have a better understanding. These amps and others like them are the heart and soul of modern active loudspeakers. |
The issue is getting smooth bass and seamless transition from sub to main speakers. Personally I've solved that issue with a combination of floor to ceiling bass traps in the corners and EQ. Others rely on multiple subs. Of course the issue of good speaker and listener placement also matter. The AM Acoustics room mode simulator is a good place to start. The reality is that subs have 2 problems. The room and the main speakers. You must blend it into both at the same time and I know of no easy way to get around measurement. The Distributed Bass Array is not to my mind easy, cheap or something everyone can implement, but it has it's fans for a reason. |
@kraftwerkturbo It's a real thing. I suspect much has to do with the appropriate high pass filter though. Several a'goners who I have convinced to try raising the HP point from 40 to 80 Hz or higher have reported the improvements along those lines. I have had this happen with 1 sub. It's not about how many subs but about the sub to main speaker integration, but if you want to add subs, who am I to stop you? |
Hey @barts - Honestly always a conversion more than subwoofer addition. The upper crossover point will depend on how they measure in cabinet and with the upper sections in place. The advantage of subwoofer appliance is freedom of location in the room. The disadvantage is you can't go higher than 80 Hz or so. |
Please read above. This was thoroughly discussed with @audiokinesis before. |
I’m sad to learn that Verity Audio went out of business last year despite their website still being up. I must admit that while the ideas and speaker are attractive I got here in a very roundabout way. If I had had more foresight, or if I had a better budget today I’d have made something more visually coherent like the Verity models. I'd also have kept the top units sealed and therefore much smaller. Among the big desires for me in this project is to fully re-implement the 2-way crossover and have full control over the equalization. I thought about going the miniDSP route, with the Flex HTx - but my Goddess how the cable count balloons. |
@devinplombier - Perhaps some of the most elaborate internal bracing systems ever construed was the B&W Matrix. Definitely too much for me but also served as I think inspiration for some really elaborate DIY cabinet construction since then:
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No, the horizontal braces are well ventilated. Since the drivers are identical AND they will have the same electrical signal there is no need to isolate the cabinet spaces. Also solid bracing reduces the internal volume so would require a larger cabinet. See Troels Gravesen’s site for other ways of using ventilated bracing, and for fun look up the B&W Matrix designs.
Aesthetics. This is how they were designed to be installed. . See the back of any powered subwoofer ever made.
Not really. In truth many have suggested that turning the insides of a speaker into a kind of diffuse field that avoids coherent (i.e. flat) reflections is the way to go. At the wavelengths involved here ~ 7' I'm not concerned.
The enclosure for the amp is really to reduce the opportunity for microphonics and long term part stability. The enclosure is, again, as recommended by the manufacturer. Alternatively you can avoid using the enclosure altogether if you can guarantee a minimum of spacing between them and anything flammable.
I’m glad I could tickle your own interest. While I did opt for 2 cabinets you could also consider using only 1 woofer per cabinet and 2-way amps instead of three, perhaps giving you the ability to put a cabinet under each surround speaker as well, if you were so inclined. The drivers however are not the most expensive part of these builds. The cabinet and amps are. |
The floor to ceiling bass traps, and wall to wall traps on the floor behind the entertainment system is in large part why I can avoid doing Distributed Bass Arrays and still get excellent results. That not only tames room modes and help EQs work better but also improves speaker placement choices.
Yes. See above. Speaker placement is not something I have a lot of flexibility with so significant room treatment has been added to the listening area.
For details on the monitors see here. The subwoofer drivers are Dayton 10" RSS265HF-8.
The final design and construction is ordered from Solen.ca (tariffs and all)
Sir, are you mocking me? WTF? Let me fully answer your question below.
That is correct. A large part of the reason for this project is that I want to rethink the mid to treble crossover. I did a measurably good job with the original but having done an active 3-way center I realized just how easy doing it better would be if active. I know audiophiles for some reason think they can install a subwoofer by trial and error. Honestly mostly it turns out to be garbage they are happy with. Sorry. They cross too low and are left with too many compromises. Yes, in this case by comparison the DBA approach removes a lot of complexity assuming you use the DBA to a high enough crossover point (80Hz or so) and so has a much higher success rate than setting a single subwoofer or two by ear. I know I’ve been teasing you all by using the term subwoofer. It is true that Dayton markets this driver as a subwoofer, and for good reason. It has good output to 20 Hz and significant excursion and power handling capabilities without being completely inefficient. This driver also has another important feature:
Lets stop talking about subwoofers and talk about this project as a new 3-way speaker system. Instead of thinking of adding a subwoofer and crossing around 40-80Hz I’m now thinking 150 - 300 Hz. The determining factors are:
Generally speaking I want to cross my new woofers as high as possible while still maintaining excellent off-axis response, not something a lot of commercial speakers have. In other words, I cut them off before they start to beam. Having the woofers located under the mid-woofers means I can cross higher without fear of the ear locating them, unlike a subwoofer appliance. By crossing high (150-300Hz) I reduce the load on the mid-woofers, increasing dynamic range but also has the extremely beneficial side-effect of reducing audible distortion even while playing low. I wrote much more about picking crossover points in my blog here. |
@jc4659 It's quite likely I've seen that before and it's stuck with me. Unfortunately that (relatively) ugly plate amp is not going to want to be seen. :) |
@scotandholly There is a lot that went into this that has to do with my aesthetics, complete lack of willingness to add more bass cabinets and wanting to take the positive experiences I had with an active center channel and bring that over to my main speakers. So, if you look at this from the perspective of "how to add more bass" this project won’t work for you. For me this checks off a lot of aesthetic and personal interest boxes. Conversely I’m not about to try to convince anyone this would work for them. Just sharing in the fun of the project. Otherwise, those who insist I need to do DBA can look at this live picture of me and sigh away.
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Not sure what you are replying to @scotandholly |
Plate amps are not on order. They are on my dining room table.
@onhwy61 - That was kind of the goal, but I guess hypothetically you could put it anywhere. The massive reduction of separate electronic components is high on my list of features.
Thank you.
Thank you for the suggestion. It’s not shown in the image but the cabinets will have threaded inserts sized for IsoAcoustic Gaia II footers. My modest space will require the cabinets be half on and half off of a rug. Spikes are a PITA on a wooden floor and I’ve had excellent results with IsoAcoustics. I'd rather have something I can push around without scratching the floor. :)
My Libra soul’s requirement for symmetry would never allow this to happen. In these dimensions, if I had the energy and money to experiment I’d probably have been well served by using a single floor firing woofer. In the early design phase I had a choice between 1 woofer, ported or 2 sealed based on their volume requirements. I could have done one downward firing woofer. I’d get to ~ 20 Hz with about 84 dB /1W. I really thought a lot about how Snell did it. However! Snell also had long term reliability issues with that setup AND I just don’t have the energy to play with finding the optimal height. While I really love how the Snell A series sounded, I strongly suspect there was more to that downward firing woofer than just mass loading. The size of the cabinet and distance to the floor probably played an enormous part in the success of that speaker. I didn’t want to half ass it without being confident I fully understood the design parameters. 2 forward firing 10" woofers starting from the ground up, crossed at ~150 Hz.... that I understand. At the end of the day I traded 1 ported for 2 sealed drivers, gaining 6 dB of sensitivity (90 dB/2 watts) with an expected anechoic of ~ 40 Hz. In this room I’ll 100% take it. I suspect the room gain and modes will have me using EQ to reduce the bass, not adding to it.
Well this is a problem for ANY multi-way speaker, so lets keep our concerns in proportion. With the traditional multi-way you would have baffles between the woofer and mid, and share the sides. That’s a lot of contact area to transmit vibration. One way or another I’ll use isolation under the 2-way speakers on top. The contact surface from the bottom section to the upper will be very small compared to a single monolithic 3-way. Currently the speakers are using speaker stands from Butcher Block Acoustics. I’ll make some final decisions about isolation when the cabinets are in. I’m sure I can address that, the issue is more about my ear height and where I want the tweeter and mid-woofer to be in relationship. The other real concern, which Duke brought up earlier is making sure your speakers don’t "rock" the wrong way. That the woofers aren’t pushing the speaker back and forth causing a kind of Doppler distortion. You may have seen me suggesting weight son small stand mount speakers to reduce this. Maybe also help to know that while these drivers are called "subwoofers" due to their ability to play low I’m using them more as a traditional woofer. They’ll cross high but go deep.
Exactly. But glad you found something that works for you in shows... those rooms are killer. |
Hi @audiokinesis - Thanks for your feedback. You are not the first one to suggest that. I’m limited by two overriding priorities: - General dimensions of the cabinet are set by current speaker footprint. - Hypex plate amplifiers are BIG! The combination of that, plus chosen drivers prevented side mounting or front/back woofers. The plate amp is just too long to allow for a woofer on the same surface. Back to back mounting on the sides was also not possible because of the narrow width I wanted to stay within and the depth of the woofer motors. I did take the woofer motor's ability to rock the cabinet into account and have sloped the front baffle back by 2" to reduce the amount of possible rocking. Also, there are 40 lb. speakers that are going to sit on top of those cabinets. I think that with the excess bracing I should be in good shape. Ideally though I wanted to do something similar to Snell, putting both woofers near the floor, but alas, aesthetics and limited budget for a new home have won out. |
@tomcarr Yes indeed. I've heard it happen. Also check out the AM Acoustics room mode simulator for help with placing your speakers and listening location. |
