Hi I'm Matt

[Matthew J Poes]

Hi Everyone, I'm Matt. I live in the Chicagoland area and hope to meet other like minded individuals. I used to participate in the DIYAudio Forum, AVSForum, and Home Theater Shack but have really lost interest in a lot of those forums. While I still post on AVS, its very limited.

I recently completed a dedicated soundproof home theater and have been working on the acoustics over the last few months. I hope to share my work and results as it goes.

I'm a social scientist, of sorts, with a background in human development and statistics. I've also taken courses in acoustics, acoustical physics, acoustical engineering, and acoustical architecture over the years to expand my knowledge, and while I don't work in that field professionally, very much enjoy it. Having said that, I have a small side business doing acoustic measurement, treatment design, soundproofing, and some installation. So far I've done mostly commercial spaces such as offices, hotels, conference spaces, universities, etc. I have a few home theater clients and hope to do more. While extra money is always nice, I really do it for the fun. I love music, movies, and learning how to reproduce these in new and better ways.

Current Setup

Video:
JVC RS1 Projector
Spandex Screen on SI Screen Frame (Previously used Black Diamond)
Sony UBP X800 UHD BR Player

Audio:
Onkyo TX-NR709 (Some capacitors replaced, opamps replaced, resistors on pre-out, etc.)
Acurus A200 Amplifier
Crown DSI4000
Laptop with Tidal (HDMI Digital Connection)
Acoustic solid turntable
Grado Phono Cartridge (wood body, forget exact model)
Rega RB250 Tonearm
Music Fidelity X-LPS with external power supply, Completely rebuilt with .5% metal film resistors, Panasonic FC caps, Wima Caps, Rifa Caps, V-caps, Burson Discrete Dual opamps (I completely rebuilt this, replacing nearly every part. The critical RIAA stage was rebuilt with very tight tolerance parts that I further hand sorted to ensure L-R channel balance, its as good as this basic design)

Speakers:
3x Gedlee Abbey for LCR
4x JBL 8340 Side Surrounds
2x DIY M&K/Vifa TriPole Surround (Purchased parts, minus crossover and some drivers, for M&K Tripole surround, designed crossover similar to Joseph Audio using 3rd order/2nd order filters with trap filters 1 octave below crossover point)
2x Gedlee 12" Bandpass Subwoofers (B&C 12TBX100 drivers)
1x Dayton RS12 sealed subwoofer
1xB&C 18DS115-4 Ported Subwoofer (19hz Tune)-awaiting driver, enclosure complete
2x Buttkicker Tactile Transducers

Room and Acoustic Treatment:
25'x11'x8.5'
Wall and Ceiling Construction: 2x 5/8" Type X drywall, Green Glue Constrained Layer Damping, Hat Channel, Decoupling clips
-Three walls are surrounded by Concrete Foundation. Two of Foundation Walls have 24" space between Theater wall and Foundation wall.
-Rear theater wall is ~14" thick, double stud construction, with double communicating door assembly (With 12" airlock space between doors).
-HVAC, Spiracoustic based HVAC mufflers, HVAC ducting is 28 gauge damped steel with acoustic lining (1.5" thick), plenum/expansion chamber on both supply and return. (Being Honest, this wasn't as successful as I hoped, the mufflers and duct lining did not fully prevent the transmission of sound into other spaces, especially low frequencies. I may work on improving this.
-False Wall for Screen and to hide speakers. Entire 30" depth of front wall is covered (100%) with multiple layers of 2" Linacoustic insulation, including the ceiling. Front wall has 2 layers with plastic membrane. Ceiling/Wall corner is bisected by 2" insulation.
-False Wall fabric Appearance Panels are lined with 3.5" Blue Jeans Cotton Insulation, spaced 30" from the wall (Acoustic insulation with a 30" airgap provides very high LF damping, when combined with a damped membrane, can provide substantial LF damping with littler comb filtering problems)
-3 Seat riser near middle/back of room. 2 layers of plywood, greenglue, acoustic insulation, perforated top around wall barrier

Acoustics in place right now:
8X 24" Vicoustic Wavewood Panel Cloud at ceiling first reflection point
8x24" Vicoustic Premium Cine Panels in 4 panel groups at first reflection points, adhered to 2.5" timber frame lined with Blue Jeans Cotton Insulation, plastic membrane.
1x36"x56"x5" DIY Bass Trap with two layers of OC703 FRK back to back, membranes facing opposite directions (One near wall, one on front), mounted with 1" airgap
2x24" Vicoustic Wavewood Panels near side Surround Wall Location
24"x24"x48" Bass Trap (4" 6lb Rockwool creating a hallow chamber lined with a heavy plastic membrane and moderately filled with scrap insulation)
2x 24"x48"x4.5" Panels with 4" Rockwool, 6lb, cork Membrane on rear of panel. Currently resting against the wall below the side surrounds at the MLP

In The works:
-Second 24"x24x48" bass trap, both will be stacked floor to ceiling in the front right corner
-24" Corner Subwoofer trap for back of room
-60"x96" Hybrid Diffuser/Panel-Membrane Bass trap for Front wall between speakers. Will reduce HF absorption and increase LF absorption.
-Modified MLS Scatter/Diffuser plate for rear bass trap front (should further reduce midrange absorption and increase LF absorption)
-QRD/PRD Diffusers (Still figuring out location, may replace First Reflection Point Panels with these)
-QRD/PRD Diffusers Cloud (Will tie into current cloud and extend to first row of seats
-Step Diffuser (Plan is to mount 4.5" panels at floor to 24" up, then mount step Diffuser above these)
-False Soffit Bass Trap with LF limiter through outer membrane mounted long right wall/ceiling (Left size has real soffit), Something Similar along back wall
-Hanger Traps mounted from Ceiling behind false wall, will hang down to just above the mains
-Used Studio Monitor Controller as analogue preamp
-DAC (Not sure what, leaning toward Teac with balanced output, 3 or 5 series)
-Additional Amplifiers, Apogee SA-800B (Extremely low noise, low distortion, high power pro amp from mid 90's)

I'll post pics when I get a chance. I have numerous measurements of the room at various states including substantial improvements in RT60, LF decay, etc. The response has a 3 db rise at 20hz starting below 200 (Tilt) but still has a bit of garbage, need some better setup of subs still and more eq work.

 

[Todd Anderson]

Hey Matt! Let me be the first to roll out the welcome carpet!

Glad to have you aboard! Sounds like you're going to fit right in!

When you get a chance, definitely head over to the Showcase and create a page for your setup. Sounds sweet!

Look forward to seeing you around the forum!

Best, Todd

 

[Sonnie Parker]

Howdy Matt... certainly glad to have you with us.

That is a mighty long list of equipment/gear you got yourself... and some nice stuff too. A lot of DIY projects... very cool.

 

[Matthew J Poes]

Thanks Everyone, appreciate the messages. I told Sonnie in a private message that I really like how this forum has the same feel as the other forums used to be. People are kind, openly sharing with each other. I see no judgments and no harsh comments. That's great, right? This is about fun.

 

[chrapladm]

Hello and welcome to the forum.

 

[Todd Anderson]

Thanks Everyone, appreciate the messages. I told Sonnie in a private message that I really like how this forum has the same feel as the other forums used to be. People are kind, openly sharing with each other. I see no judgments and no harsh comments. That's great, right? This is about fun.

Yup... that's what it's all about!

 

[mechman]

Welcome to Nirvana Matt! Great to have you join us here!

 

[Tonto]

Welcome aboard Matt, always nice to have another enthusiast around. Sounds like you enjoy this stuff as much as we do. And thanks for the compliment, we try to keep things simple & uncomplicated...just nice folks here!

 

[GFOviedo]

Welcome!

 

[Mark C Flick]

Hey Matt, welcome aboard.

 

[tripplej]

Welcome!

 

[tesseract]

Welcome, Matt, glad to have you here! That is an impressive array of hifi goodies you have amassed.

I was just discussing the Abbey, Econowave and SEOS with a few friends this morning.

 

[Matthew J Poes]

Welcome, Matt, glad to have you here! That is an impressive array of hifi goodies you have amassed.

I was just discussing the Abbey, Econowave and SEOS with a few friends this morning.

Thanks for the welcome. I’m obviously a fan of this kind of speaker or I wouldn’t own them. I’m friends with Matt Grant who has designed many of the better SEOS based kits and speakers. They are an excellent value.

I’d be curious what the conversation was earlier. Those three aren’t talked about together much anymore it seems.

 

[tesseract]

The conversation centered around on axis listening and measurements being a preferred method to off axis, with Ethan Winer pro on axis and Andrew Jones in disagreement. The Abbey has a known axial hole and is not recommended by Earl himself for on axis listening, I used it as an example because there was doubt from Ethan that one existed.

It is hard for me to hear of SEOS, Audio Kinesis, GedLee or Zilch without thinking of all the players involved in the latest waveguide evolution(s).

 

[Matthew J Poes]

The conversation centered around on axis listening and measurements being a preferred method to off axis, with Ethan Winer pro on axis and Andrew Jones in disagreement. The Abbey has a known axial hole and is not recommended by Earl himself for on axis listening, I used it as an example because there was doubt from Ethan that one existed.

It is hard for me to hear of SEOS, Audio Kinesis, GedLee or Zilch without thinking of all the players involved in the latest waveguide evolution(s).

Yeah any waveguide speaker with equal dimensions will have such a hole. When toes properly the hole exists near the wall so nobody would ever hear it.

Sorry I’ll just be blunt. When it comes to waveguide or controlled directivity speakers, Ethan is wrong. All speakers have a listening axis and it’s not always on axis. But that isn’t the reason for listening off axis with waveguide speakers. As you probably know the waveguides with proper dispersion control get quieter the farther off axis you go. That means with heavily toed speakers the center image remains stable over a wide area. That is something only a CD speaker can do. None of those kinds of speakers should be listened to on axis. I feel like that is more a fact than an opinion at this point.

 

[Matthew J Poes]

The conversation centered around on axis listening and measurements being a preferred method to off axis, with Ethan Winer pro on axis and Andrew Jones in disagreement. The Abbey has a known axial hole and is not recommended by Earl himself for on axis listening, I used it as an example because there was doubt from Ethan that one existed.

It is hard for me to hear of SEOS, Audio Kinesis, GedLee or Zilch without thinking of all the players involved in the latest waveguide evolution(s).

http://www.libinst.com/PublicArticles/Setup of WG Speakers.pdf Did anyone share this paper. It does a great job explaining in lay terms why CD speakers need to be toed in.

On a separate note do you think people would like a forum post on this concept and when/where to use it? Maybe about the idea of controlled directivity, wide, Omni, etc?

 

[tesseract]

Totally agree, proper waveguides have smooth off axis response, reduced in level off axis. Dunno what my friend Ethan is on about. I want a pair of Fusion-15 Sentinal in the worst way after having heard @DrDyna's pair.

I've never seen that particular paper before, looks a lot like one Parham made, then I saw his name listed at the bottom. A directvity thread would be most welcome here, for sure!

 

[Matthew J Poes]

Totally agree, proper waveguides have smooth off axis response, reduced in level off axis. Dunno what my friend Ethan is on about. I want a pair of Fusion-15 Sentinal in the worst way after having heard @DrDyna's pair.

I've never seen that particular paper before, looks a lot like one Parham made, then I saw his name listed at the bottom. A directvity thread would be most welcome here, for sure!

My friend Matt designed the Sentinal it’s a great speaker.

The HTM-12 is also a great speaker. The midbass is a little cleaner (lower in distortion) and they use basically the same waveguide and Cd.

I really wish Matt would make an HTM-15. It would have to use the larger SEOS 18 waveguide so he’s expressed concern the high cost would be too big a turnoff. Such a speaker would fully embody what Dr Geddes believed was ideal and provide good dispersion control into the mid triple digits.

 

[DrDyna]

I think he underestimates what people will pay for these things sometimes, I mean, the new iphone is like a thousand bucks lol.

 

[Matthew J Poes]

I think he underestimates what people will pay for these things sometimes, I mean, the new iphone is like a thousand bucks lol.

Based on conversations I've had, it sounds like there would be interest in a completed product, just not a kit. I mean, as a kit my speakers in their form were something like $1500 each, and a lot of that was material costs. When you consider that as a translation into retail, you can basically charge anywhere from 3 times that price for a finished product direct, or about 5 times if its finished to a fine level and sold through a dealer network.

The HTM-12 is about $600 as a kit, Around $800 with all parts, paint, glue, etc. An HTM-15 would have to use the fiberglass waveguide, which is $150. The 15" Kappalite is about $200. The 15" needs to be crossed over around 700-800hz, and the only 1" CD's that could do that is the BA-750 ($154) and unusual expensive models from TAD and Fostex ($$$). Add about $100 for the enclosures and $75 for crossover parts (at least). Out the door as a kit it will be close to $1500 and would be the most expensive kit offered by far (and how do you convince people to buy that over one of the larger kits like the Intrusive 1899. I def. see Matt's point, I just think its a good idea.

 

[DrDyna]

I dunno, it doesn't seem like it'd be a hard sell for me, as long as the reasoning is explained. It's probably something they should start a thread about to measure interest. If it represents the end game 2 way controlled directivity design, I don't think it'd be a hard sell for the 2 way fans. The two ways will for sure be more expensive to build once they get big enough to need to cross below 1000, but...and this is just my personal 2 cents, if the idea is that it would create market confusion when 1899 exists, I would rather the 1899 vanish. It's a redundant product anyway, just tell people to build an 88 special or a Fusion 12 and 4 18" midbass modules and stack em up.

 

[Matthew J Poes]

I dunno, it doesn't seem like it'd be a hard sell for me, as long as the reasoning is explained. It's probably something they should start a thread about to measure interest. If it represents the end game 2 way controlled directivity design, I don't think it'd be a hard sell for the 2 way fans. The two ways will for sure be more expensive to build once they get big enough to need to cross below 1000, but...and this is just my personal 2 cents, if the idea is that it would create market confusion when 1899 exists, I would rather the 1899 vanish. It's a redundant product anyway, just tell people to build an 88 special or a Fusion 12 and 4 18" midbass modules and stack em up.

I’ll probably never stop giving Matt (MTG90) ideas on what would be a great speaker. What he and EricH decide to build will ultimately be based on what they think will sell.

For what it’s worth, while I prefer a 2 way design for the vast majority of the response range, I’ve had an idea for a complex 3 way design based on a symmetric array and the Horbach-Keele crossover. In my idea, there would be a pair of 18” drivers, a pair of 15” drivers, and a single 18” waveguide. It would have to use electronic crossovers with FIR capability and 3 amp channels per speaker. It would be relatively expensive. It would also be the ultimate expression of a controlled directivity speaker in a Home. I’ve talked to Matt about this who I think thought that was nuts and maybe best as someone’s one-off project rather than a kit.

I have thought about doing a smaller version using my existing speaker. Basically build modules. Another 12” B&C 12tbx100 and a pair of 18” midbass drivers. It would be nearly 8 feet tall I suspect. I would then need to use something like a pair of Minidsp 2x4hd’s for the crossover. One of the FIR filter generators can natively handle H-K crossovers. Not only would such a speaker have constant directivity to below the rooms crossover region, but it would also gain significant directivity control vertically as well in the midrange and midbass area.

I would jump on such a project if not for the high cost of entry. Coming up with 4 more amplifier channels and two dsp devices is too much for me right now.