ANGEL CITY SERAPHIM SPEAKERS
$8,000 PER PAIR
Background - I want to share a rather unique experience I had recently in watching the design, manufacturing, and marketing process for a new loudspeaker. I got to witness this process from the conceptual ideas to picking topology, drivers, crossover parts, marketing, and ultimately to the finished product.
In order to effectively convey this process, I decided to conduct an interview with CTO Hugh Nguyen to expose you to the man, his philosophy, and what makes him function as a manufacturer, music lover, and audio visionary. This will give you the framework to read the review and more thoroughly understand as I share my experiences.
HUGH: “In addition to our new Seraphim you have, we are currently manufacturing the Trinity, a 2-way monitor speaker. (Seen in picture) We are also the Melody Valve HiFi US Distributor with other lines such as Danny Richie’s (former StereoMojo head technician) LS speakers: the LS6 & LS9. (Both of these great speakers were StereoMojo’s world’s first reviews after Danny left us). We sell through a network of dealers in the US and we’ve been in business since 1999.”
“The Seraphim was created because we knew all along the woofers used in the Trinity were special so we decided to use a variation of it and my friend Lee Matuszczak (MG Audio) completed the rest of the design.” (StereoMojo was also the first to review MG Audio Cables that turned out to be one of the best sounding speaker cables and IC’s we’ve heard at any price. The MG Planus IIIAG is our current BEST PRODUCT – CABLES award winner.)
“As good as the Trinity is, we always knew we should design a floor standing speaker which would (will) give us more low-end performance and a smoother high-end. The goal of the design was to expand on the already considerable capabilities of the Trinitys. We wanted something a little smoother in the top end with much better bass depth and weight. We also wanted a speaker with greater dimensionality within the sound stage. Going to a 3-way topology in a larger enclosure offered the prospect of improved bass extension, a cleaner and clearer midrange, and smoother hi-frequency performance.”
Hugh mentioned the Trinity. The design process at the time looked for a driver which could do bass reasonably well, but the focus was on the magical midrange quality we all look for because that’s where 80% of the music lives. Hugh also needed the driver to be efficient enough and with the right electrical/mechanical parameters to support tube electronics. Hugh found a European driver he really liked and it became the starting point for the new design. Moving forward he wanted to keep the magic ingredient he had found and build upon those strengths. Add more extension in the bass a better tweeter and integrate these drivers with the midrange driver. He worked with his designer and they decided to keep the same driver in the bass would both extend the response and keep everything of a single voice. Considering the electrical and mechanical parameters of the driver, this approach made sense.
A well-engineered enclosure/box, world class drivers from Europe, crossover topology developed by computer modeling, carefully validation through listening tests, and selection of all crossover parts based on painstaking listening tests. About the crossover, Hugh said, “The Seraphim employs 2nd and 4th order acoustical crossovers for the woofer to midrange and midrange to tweeter crossovers, respectively. These are implemented with combinations of 2nd order electrical networks that factor in the acoustical roll-off characteristics of the drivers to achieve the desired target responses. Crossover points are approximately 400 and 2000 Hertz. The crossover is implemented using premium components, including foil inductors, film and foil capacitors, and non-inductive wire-wound resistors. Component parts were selected to meet the sound objectives of the loudspeaker.”
The speaker was not designed to a price point, but based around a concept, a size, a specific set of drivers and then around the right sound. When all was said and done, they added the various costs and priced the speaker accordingly. The key in my mind is they didn’t back into a price but within “reasonable/sensible constraints” they put together the best combination of parts to arrive at their final sound. Don’t get me wrong, they would never have considered an over the top part such as a $600 dollar capacitor (one for each speaker). They instead found the correct value and then listened to a dozen plus brands within some reasonable limit to arrive at the right sounding part for the specific topology and location within the circuit.
At Stereomojo we love to reveal industry “Dirty Little Secrets”. A dirty little secret from many manufacturers is that they specify that the crossover cost in total can’t exceed some predetermined value to fit within the overall retail price of a loudspeaker. Let’s say a speaker is designed to retail for $500 so the cost in parts is around $100. Taking into account enclosure, drivers, and connections, how much do you think the entire crossover with multiple capacitors, chokes, resistors, wire, and board for mounting cost? Maybe $15 to $20 dollars? Yes, I’m guessing the magic capacitor in that case might have cost $2 to $3 tops. Obviously this approach is based on mediocrity and hitting a price based model target. It might work in the lowest end product but not for an intelligent design.
The ACA design team listened to individual parts including drivers, crossover parts, wire, and even connectors. As an example, they listened to a single capacitor value and found a product price range and specific brand which was the sweet spot. You could double the price but only improve the sound by 5% so it wasn’t a smart approach. This approach will cost more but will yield a far better, more refined and coherent sound quality at the end of the day. I can tell you many hours were spent listening to the same exact value capacitor in the circuit and finding the one that had the best balance of attributes. Cost is not always related to sound quality so you have to listen carefully and choose accordingly. Again, an intelligent design approach focused on ultimate sound tempered by price. If the cheapest was always the best value, we’d all be driving Yugo’s!
Another example of the quality of the parts in the Seraphims is the Cardas speaker posts on the rear of the cabinets. The Cardas' are held by many as the best sounding speaker posts avialable at any price. They are also the most expensive.
Amplifier matching should be pretty easy with the Seraphim’s 91db sensitivity rating making it very tube friendly. Depending on room size and how loud you listen, you might get by with as little as 20 W per channel. Otherwise, with less expensive solid-state amps, you might want to aim more towards 60 W per channel.
Voicing the Final Speaker
..and I helped…
This is a contentious topic but one I believe has to be acknowledged and talked about. Every designer ultimately ‘voices’ their speaker to provide a sound quality which tracks to their or their team’s perception of a fine high quality loudspeaker. Every single parameter of a loudspeaker imparts sounds, distortions, and compromises into the final product. A great designer finds the correct combinations of trade-offs and with the help of key listening members arrives at a final voicing which meets the design objectives. I watched this process and actually got to give my opinion on occasion about what I heard. Was a change more transparent, did it support a bigger soundstage, did it take the sound to a ‘brighter’ place as opposed to a ‘warmer’ place. What parameters and changes worked to enhance the sound and which changes just changed the sound but did not enhance the overall experience? These are hard decisions and took a lot of work and effort to arrive at a final answer. I never once heard a given part was xx% more expensive or cheaper. It was always focused on the ultimate sound quality and then the part cost was the part cost. I thought the overall design process was focused on what provided the best balance of sound quality & emotional response.
The Seraphim projected a wide and deep soundstage with excellent image placement within the overall sound scape. They were very transparent, disappearing into rooms which support great imaging. As you will notice I stated the ability to disappear very carefully since many rooms and situations don’t support a good speaker sonically disappearing. A good example is often the hotel rooms we hear at shows. Based on room dimensions, furniture, curtains, wall coverings, seating, and the number of people crowded into the room, the end result can be a room which ultimately doesn’t support speakers disappearing very well. I have heard many speakers sound very different based on the rooms they are put in. Often, the room has more to do with the actual imaging, soundstaging, and transparency of a speaker than the actual speaker. Obviously you can’t take a poorly designed speaker and make it much better by the room it is put in. Conversely, you can take a great speaker and put it in a poor room and make the speaker sound as though it was poorly designed.
The overall nature of the Seraphim’s’ sound was very organic yet detailed in a musical versus hifi kind of way. The tonality of the speaker was excellent on female vocals and acoustic instruments. The speaker had a dynamic snap even with tube electronics which made the experience very special. The midrange was magical with the upper-mids and highs simply extending and supporting the special midrange quality. No overemphasis or tipped up top end.
A top shelf driver and crossover can be completely wasted if the enclosure is not a top shelf design as well. Concerning the enclosure, Hugh stated, “The Seraphim cabinet is constructed from 1-inch MDF and has extensive internal bracing. The left and right sides of the enclosure slope in slightly towards the top to help reduce standing waves. Portions of the front of the enclosure are 2-inches thick to improve rigidity and the tweeter and midrange drivers are in their own separate internal enclosures separated from the woofer section by 1-inch partitions. The woofer section is ported out the back of the cabinet using a large double-flared port. The port mounting location and size were chosen to reduce port noise as much as practical. The rounded corners used on the front face of the enclosure help to reduce diffraction effects and were carried through to the other enclosure edges for consistency.”
The rear cabinet ported bass response was tight and controlled in ‘most’ situations. The room I heard the speaker in the most was a large great room. The speaker was able to go very low and fill this large space nicely. When I heard the speaker in a much smaller room it was obvious it quickly overloaded the room and the bass sound quality detracted from the overall experience and clarity of the speaker. Frankly, this isn’t a fault of the speaker but of the room it is placed into. You can’t cheat the laws of physics. In a reasonably sized room the speaker is capable of great bass and power. At RMAF and the levels they were generally playing music it was not a problem. I bet if they had gotten on the volume then we would see the room overload.
As far as available finishes go, the first batch will be offered in a very beautiful, high quality polished Piano Black. They are planning to offer additional veneer finishes such as Piano Rosewood and Piano Bird Eyes Maple but these are only for the sides and top while the rest will stay as Piano Black.
Speaker Parameters – The Seraphim is a 3 way floor standing loudspeaker with the following design parameters and specifications:
Tweeter: SEAS T25FC001 soft dome (x1)
Midrange: Custom ACA 7” (x1)
Woofers: Custom ACA 7” (x2)
Transmission line design for the woofers
Frequency Response: 28Hz – 21kHz
Impedance: 4 Ohms
Point to point crossover construction
Well braced and damped cabinets made from MDF
Dimensions: 14”W x 47.5”H x 21.5”D
Weight: 260 lbs. /pair
I think the end result of this design process was a very competitive loudspeaker that can fill the musical bill for most people. The speaker works extremely well with both tube and solid state electronics. Hearing the midrange of this speaker with a Melody Audio tube set-up was magical and revealed why so many people love tubes. There was an organic quality and realness to vocals which is often very hard to capture with solid-state electronics. The bass quality with tube electronics is much better than I would have thought. My general experience is many speakers get very loose, wooly, and generally flatulent with tube electronics. The Seraphim seemed to hang on much better than most and provide a good, solid balance with the rest of the speaker voicing range.
The Seraphim’s do not discriminate when it comes to musical genres. If you love vocal music, the lovely midrange is right up your alley. Small jazz ensembles to large orchestral works are all rendered immaculately via the soundstage.
Since these are floorstanding speakers, they would be adequate for most medium to large rooms.
Picking a set of speakers is a very personal experience for everyone. We all have different requirements, different listening biases, love different types of music, and search for the perfect combination of our most important attributes. The ACA Seraphim is an excellent speaker that can stop many people’s search for the perfect loudspeaker. The beautiful midrange coupled with tube electronics and the resultant sound is well beyond the asking price in my opinion. I recommend you take the opportunity to audition the speaker or seek them out at a regional show to hear what they can do. I have heard very few speakers around this price point which don’t have some areas of weakness which you would have to consider very carefully. With the Seraphim you get it all and then some.
Because of the outstanding price to performance ratio, we have given the ACA Seraphim our highest
MAXIMUM MOJO award. Congratulations to Hugh Nyguyn and Angel City Audio.
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