Producing powerful, effective, and pleasing audio requires a tenacious commitment to quality. Every part of a loudspeaker, from simple washers to complex, customized cones, must align with strict quality standards. Your sound experience deserves nothing less.
Jess Landgraf, MISCO’s Quality Manager, fully commits the MISCO team to this challenge. Landgraf emphasized the importance of understanding quality not just as a set of measurable metrics, but as a narrative.
“At the end of the day, all of these numbers are just stories, ways of making data quantifiable—but it’s the story behind the numbers that really matters,” Landgraf explained. The story underscores why an audio solutions manufacturer should maintain high standards while remaining adaptable to customer needs and industry advancements. Here’s how we do it.
Tiered Inspections
MISCO’s quality management system uses a tiered inspection process, ensuring every component meets its intended purpose without overburdening resources and adding non-value-added cost. We apply different levels of scrutiny based on the component's criticality and performance history.
Dock-to-Stock: For Trusted Vendors and Low-Risk Components
Low-risk, simple components, like polyfill and standard fasteners, are routed directly from the dock to stock, reflecting our confidence in long-term vendor performance and component consistency.
“For example, the Polyfill we use in speaker enclosures moves directly to stock because we’ve had enough history with the vendors of this product, without defects, to know it’s likely going to be fine,” Landgraf said.
Visual Inspection: A Flexible Middle Tier
Components that carry some risk–or come from vendors with a history of minor issues–undergo visual inspection. Our team can catch problems visually by confirming dimensions, checking for defects like dents or misaligned parts, or ensuring that a sample size of components matches reference drawings.
“Visual inspections are non-measurable, usually product-specific, and typically don’t generate records, but still allow us to track history while ensuring basic quality,” Landgraf said. “Sometimes, we’re just looking for something simple, like paint finishes on baskets or grilles. Other times, if there’s a history of non-conformance, we’re more likely to do this visual inspection just to make sure they are conformant. But since it’s still not measurable, these inspections usually focus on cosmetic issues.”
Inspection Records: For Critical and High-Risk Components
Critical speaker components, like cones, baskets, voice coils, and plates, require a full, documented inspection record. These records create a paper trail to ensure long-term traceability and support root-cause analysis.
“There are two reasons why products would hit the third inspection category,” Landgraf said. “One, the part is so critical we need to make sure that it meets the spec. The other reason is that we've had such trouble with this particular product being non-conformant, we need eyes on it every single lot. It might not be that critical of a component, but we’re keeping eyes on it to ensure spec conformance continues to be met.”
“You can’t make a good speaker without good components. It’s that simple,” Landgraf said.
Vendor Management and Scorecards
MISCO’s dedication to quality extends to our vendor relationships. We use a vendor scorecard system to provide a transparent, measurable way to track supplier performance and address shortcomings.
Our vendor scorecards evaluate suppliers based on several critical metrics:
- On-time delivery: Are shipments arriving as scheduled to prevent production delays?
- Shipment accuracy: Are the correct quantities and specifications being fulfilled?
- Quality metrics: How often are parts rejected due to non-conformance?
- Responsiveness to corrective actions: Are suppliers addressing issues promptly and effectively?
The scorecard converts these metrics into a numerical rating, providing an easy-to-understand overview of each vendor’s performance. However, Landgraf reiterates the real narrative behind the numbers.
“These metrics aren’t just data points,” Landgraf said. “They’re ways of understanding and improving our relationships with suppliers.”
While the scorecard system provides an objective way to evaluate vendors, we also recognize the value of long-term relationships, especially in niche industries where suppliers may be irreplaceable. For Landgraf, the story is more about taking preventative measures to ensure long-term quality and cultivating sustainable relationships with reliable suppliers.
“If a vendor scorecard is low, but the vendor has strategic importance, we give them special attention to help them improve their score,” Landgraf noted. “We’ve had a couple of vendors say, ‘What can we do to make this number grow? That’s the kind of collaboration we’re always happy to support.”
In-Process and End-of-Line Testing
To ensure consistent quality and performance, we implement meticulous testing throughout the manufacturing process, from initial assembly to final product evaluation. These processes not only catch defects early but also reinforce our commitment to delivering reliable, high-performance speakers.
In-Process Testing: Precision at Every Step
During assembly, we embed quality control measures at nearly every stage, ensuring that components are properly aligned and secured. These checks range from torque testing screws to ensuring precise glue weights for critical connections.
“Every time something is connected to something else, there’s a check,” Landgraf said. “Whether it’s a twist check, a torque measurement, or glue weight validation, we make sure each part meets the spec before moving forward.”
Some specific in-process checks include:
- Torque tests: Ensuring screws and rivets are fastened to the correct specifications.
- Glue weight validation: Using calibrated scales to measure the exact weight of adhesives applied.
- Solder joint inspections: Confirming that solder connections meet industry standards and are free of defects.
These proactive measures allow MISCO to catch potential issues during assembly, reducing the likelihood of defects later in the process.
End-of-Line Testing: Ensuring Performance
Once assembly is complete, speakers undergo extensive end-of-line testing to verify their performance. We employ several quantitative production validation tests before passing speakers to our customers, beyond a simple “rub and buzz” test.
- SoundCheck testing: MISCO utilizes an advanced, multi-part method involving complete loudspeaker measurement analysis to evaluate loudspeaker performance, measuring metrics such as:
- Frequency response, to identify unplanned peaks or dips and ensure it falls within a defined tolerance window consistent with the driver's intended purpose.
- Total harmonic distortion (THD), to measure the ratio of harmonic components to the fundamental frequency.
- Impedance margin, to reveal issues with voice coil wire, loudspeaker stiffness, moving mass, or inductance changes.
- Average sensitivity, to identify issues of low sensitivity that can cause end-users to compensate with higher power.
- Resonant frequency, to ensure it doesn’t throw off the tonal balance of the entire audio system.
- Polarity, to ensure that the wiring has been installed correctly.
“Rub-and-buzz is great for basic quality assurance, but SoundCheck gives us detailed data that are invaluable for critical designs,” Landgraf said. “It’s the highest level of inspection we can do at the end of the line.”
The quality control process evolves throughout the speaker’s design, ultimately culminating in a complete check before the product is shipped.
“At incoming inspection, we sample components. But at the end of the line, if we’re doing rub-and-buzz or SoundCheck, we’re testing 100%. That’s the level of assurance we provide to our customers,” Landgraf said.
ISO Compliance and Internal Audits
Since 2013, we’ve adhered to rigorous ISO 9001 standards, prioritizing customer satisfaction, process improvement, and operational consistency. Our compliance approach combines external oversight with a robust internal audit system, encouraging accountability and cross-departmental collaboration.
ISO Certification: Structure and Strategy
ISO 9001 certification revolves around creating and maintaining process-driven quality management systems (QMS). This means documenting every process, from sales to production, and ensuring these processes meet customer expectations.
“The point of ISO 9001 is to maintain customer focus and constant improvement through processes,” Landgraf said. “It’s about documenting the steps, identifying the inputs and outputs, and ensuring that the process is effective and measurable.”
MISCO undergoes external audits on a three-year cycle:
- Year one: Full recertification audit.
- Years two and three: Surveillance audits that delve into specific aspects of the QMS.
Internal Audits: A Development Tool
Our internal audits aren’t just compliance exercises. They’re tools for staff development and cross-departmental collaboration.
Employees from various departments, such as accounting or purchasing, are asked to audit processes outside their usual roles. This gives each team a fresh perspective and often reveals areas for improvement that they wouldn’t otherwise observe themselves.
“When someone from accounting audits an incoming inspection, they may ask questions that wouldn't normally be asked,” Landgraf said. “It’s fascinating to see what they uncover and how their process interacts with others.”
This cross-training helps employees understand MISCO operations holistically, while also identifying opportunities to refine processes. Compliance issues might not seem exciting, but as with all other parts of the quality process, they’re driven by a philosophy embedded in the data.
“When I start talking about ISO, people’s eyes glaze over, but it’s not just about standards. It’s about the stories behind the data, the ways we improve, and how everything fits together to serve the customer better,” Landgraf said.
Quality is a Philosophy
MISCO’s quality approach is as much about people and relationships as it is about numbers and metrics.
Whether collaborating with vendors to refine processes, training employees through internal audits, or responding to customer needs with adaptable testing, our philosophy is rooted in the belief that quality is a continuous journey.
Learn more about why audio experts and pioneers choose MISCO.
