5 out of 5
Pricing Note
Product Description
Manufacturer Part Number: 5PF-8
The GRS 5PF-8 5-1/4" woofers feature a poly-laminate coated cone and a foam surround. They are ideally suited for all sealed-box speaker applications.
Key Features:
Overview:
GRS 5PF-8 5-1/4" Paper Cone Foam Surround Woofer
The GRS 5PF-8 5-1/4" woofers feature a poly-laminate coated cone and a foam surround. They are ideally suited for all sealed-box speaker applications. Thanks to their carefully optimized parameters, GRS 5PF-8 5-1/4" poly-laminated paper cone woofers offer a high degree of compatibility when used as replacement speakers-they also provide excellent performance in new projects, too.
Specification:
Manuals & Resources:
The GRS 5PF-8 5-1/4" woofers feature a poly-laminate coated cone and a foam surround. They are ideally suited for all sealed-box speaker applications.
Key Features:
- Perfect for use in sealed-box home theater and music systems
- Poly-laminated paper cone, treated foam surround, and polymer dust cap
- Smooth frequency response with minimal cone breakup
Overview:
GRS 5PF-8 5-1/4" Paper Cone Foam Surround Woofer
The GRS 5PF-8 5-1/4" woofers feature a poly-laminate coated cone and a foam surround. They are ideally suited for all sealed-box speaker applications. Thanks to their carefully optimized parameters, GRS 5PF-8 5-1/4" poly-laminated paper cone woofers offer a high degree of compatibility when used as replacement speakers-they also provide excellent performance in new projects, too.
Specification:
Product Details | |
|---|---|
| Brand | GRS |
| Model | 5PF-8 |
| Part Number | 292-405 |
| UPC | 844632088452 |
| Unit of Measure | Each |
| Weight | 1.15 |
Product Specifications | |
|---|---|
| Nominal Diameter | 5-1/4" |
| Power Handling (RMS) | 90 Watts |
| Power Handling (MAX) | 180 Watts |
| Impedance | 8Ω |
| Frequency Response | 90 to 8,000Hz |
| Sensitivity | 85dB 2.83V/1m |
| Voice Coil Diameter | 1" |
Thiele-Small Parameters | |
|---|---|
| Resonant Frequency (Fs) | 162Hz |
| DC Resistance (Re) | 7.3Ω |
| Voice Coil Inductance (Le) | 0.5mH |
| Mechanical Q (Qms) | 5.96 |
| Electromagnetic Q (Qes) | 3.09 |
| Total Q (Qts) | 2.04 |
| Compliance Equivalent Volume (Vas) | 0.05ft³ |
| Mechanical Compliance of Suspension (Cms) | 0.16mm/N |
| BL Product (BL) | 3.8T·m |
| Diaphragm Mass Inc. Airload (Mms) | 6.1g |
| Maximum Linear Excursion (Xmax) | 2.5mm |
| Surface Area of Cone (Sd) | 75.2cm² |
Materials of Construction | |
|---|---|
| Cone Material | Treated Paper |
| Surround Material | Foam |
| Magnet Material | Ferrite |
Mounting Information | |
|---|---|
| Overall Outside Diameter | 5.0625" |
| Baffle Cutout Diameter | 4.75" |
| Depth | 2.3125" |
| # Mounting Holes | 4 |
Parts Express Staff Recommended Enclosure Volume | |
|---|---|
| Sealed Volume | 0.18ft³ |
| Sealed F3 | 90Hz |
Manuals & Resources:
Attention CA Residents: Prop 65 Warning
WARNING:
This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.
Need more information?
Our staff are available to answer any questions you may have about this item
Our staff are available to answer any questions you may have about this item
Look Similar Items By Category
Customer Reviews
By Warren M.
Date: October 01, 2025
Speakers were exactly what I needed as replacement wolfers for my old Minimus 77's. Good price and delivery was a day earlier than expected.
Rating: 
[4 of 5 Stars!]
[4 of 5 Stars!]
By A Customer
Date: September 19, 2025
Good speakers for the price perfect fit for the Realistic Minimus 77s if you need them. Sound quality is fair construction seems very good. They are my rear speakers and they added the treble that I needed. Only mod was I had to side cut the neg. side so the quick clip would slide on.
Rating: 
[5 of 5 Stars!]
[5 of 5 Stars!]
By BRYAN
Date: March 04, 2025
This speaker will replace old Minimus 77 woofer speakers as a drop in replacement!! All I had to do to modify was with metal shears, trim the negative terminal to fit the smaller negative male blade to be able to plug in the existing wires. Took max 15 mins for both. Working fine!!
Rating: [5 of 5 Stars!]
[5 of 5 Stars!]
By A Customer
Date: September 26, 2022
Had pair of old old Radio Shack Optimus speakers as well as Realistic speakers. Another reviewer had the latter and said speakers were drop-in replacement. This is confirmed.For the Optimus speakers, the speakers were a little big but this was easy to fix. I traced the old speaker on to the new speaker with a thin black marker. Then used my grinder to remove the excess metal. Easy modification. Replacement speakers dropped right in.Few notes- The ohms of the replacement speakers are 8. My Optimus had 7 in them and the Realistic were 6. I was fine with it. No change in sound. Going up in ohms is generally easier for a system to consume vs going down.- The replacement speakers have the positive and negative terminals in reverse compared to the Radio Shack speakers. The plus is on the right but on the Radio Shack the plus is on the left. Not really a problem but something to pay attention to when installing the new ones.Overall, I'm very happy. Got my old speakers working for under $50 (including parts). Sound great. Thanks for selling these, GRS.
Rating: [5 of 5 Stars!]
[5 of 5 Stars!]
By Orleans
Date: October 16, 2021
This was a drop in replacement speaker for my Realistic Minimus -77 woofer. Sorry I don't have a completed install photo. I was in a hurry to hear the sound. You will have to crimp a larger slide on connector to one of the crossover leads to make the connection to the speaker however.
Rating: [5 of 5 Stars!]
[5 of 5 Stars!]
Items 1 - 5 of 5 reviews
1