Abstract
This document presents a budget-friendly 3-way bookshelf speaker pair designed to rival popular models like the Polk ES15 and ELAC B6.2, which retail for $250–$300 per pair. The design achieves a frequency response of 34 Hz to 20 kHz (±3 dB), sensitivity of 86.5–87 dB, and power handling of 200 W, using off-the-shelf components and a slanted baffle for improved time alignment. The total cost is approximately $371.64 per pair. This publication details the design process, VituixCAD simulations, performance metrics, and a comparison to five well-regarded speakers in the $200–$1000 range, including horizontal and vertical dispersion analysis.Introduction
Bookshelf speakers are compact audio systems designed to deliver high-quality sound in small to medium-sized rooms. This project aims to create a pair of 3-way bookshelf speakers that offer superior performance to commercial models like the Polk ES15 and ELAC B6.2 at a similar price point. Unlike typical 2-way speakers, which use one driver for bass and midrange and another for treble, this 3-way design dedicates separate drivers to bass, midrange, and treble, enhancing clarity and detail. Key features include a slanted baffle for time alignment, a 4 Ω woofer to compensate for bass loss, and a carefully tuned crossover. The design was optimized using VituixCAD simulations and is ideal for DIY enthusiasts seeking professional-grade sound on a budget.Design Overview
1. Driver Selection and Specifications
- Woofer: Dayton Audio DCS205-4 (8", 4 Ω)
- Handles bass up to 450 Hz with 100 W RMS power handling and ~91 dB sensitivity (boosted by 4 Ω impedance).
- Chosen for its ability to compensate for baffle step loss, where bass weakens as sound diffracts around the enclosure.
- Midrange: Dayton Audio RS100-8 (4", 8 Ω)
- Covers 450 Hz to 3 kHz with 60 W RMS power handling and 86.5 dB sensitivity.
- Selected for its clarity in critical midrange frequencies.
- Tweeter: Dayton Audio DC25T-8 (1" Titanium, 8 Ω)
- Handles frequencies from 3 kHz to 20 kHz with 80 W RMS power handling and sensitivity padded to ~87.5 dB.
- Chosen for its smooth high-frequency response and affordability.
2. Enclosure Design
- Dimensions: 10" W × 16" D (base) × 22" H, slanting to 14" D at the top (10° angle).
- Woofer Chamber: 1.0 ft³, ported, tuned to 34 Hz with a 2" × 4" flared port for extended bass.
- Midrange Chamber: 0.06 ft³, sealed to isolate midrange frequencies.
- The slanted baffle ensures sound from all drivers reaches the listener simultaneously, improving phase coherence.
3. Crossover Design
- Type: Dayton Audio XO3W-450/3K (8 Ω) with crossover points at 450 Hz and 3 kHz.
- Adjustment: A 4 Ω resistor pads the tweeter’s sensitivity to match the system average.
- The crossover ensures smooth transitions between drivers with minimal power loss.
4. Bill of Materials (BOM)
- Total cost: $371.64 per pair, including drivers, crossover components, MDF, and miscellaneous parts.
Simulation and Performance Analysis
1. VituixCAD Simulation Setup
- Software: VituixCAD modeled the drivers, enclosure, and crossover.
- Driver Positions: Woofer at the bottom, midrange at mid-baffle, tweeter at the top (slanted).
- The simulation confirmed frequency response, impedance, and directivity.
2. Frequency Response
- Range: 34 Hz–20 kHz (±3 dB), with an average sensitivity of 86.5–87 dB.
- Bass: -3 dB at 34 Hz, flat from 100 Hz to 10 kHz.
- Highs: Smooth roll-off above 10 kHz, reaching 70 dB at 20 kHz.
3. Directivity
- Horizontal Dispersion: Wide below 500 Hz, narrowing to ~60° at 20 kHz.
- Vertical Dispersion: Narrower, with significant attenuation at ±30° above 2 kHz.
- The slanted baffle mitigates some vertical phase issues but remains sensitive to listener height.
4. Impedance
- Below 450 Hz: 4 Ω (woofer range).
- Above 450 Hz: 8 Ω (midrange and tweeter).
- Compatible with most amplifiers, though the 4 Ω bass may require good current delivery.
Comparison to Popular Bookshelf Speakers in the $200–$1000 Range
To assess the competitiveness of this custom 3-way speaker, we compare it to five popular bookshelf speakers: the Polk Audio Signature Elite ES15, ELAC Debut B6.2, Klipsch R-51M, KEF Q150, and Triangle Borea BR03. These models are well-regarded for their balance of sound quality and value. The comparison includes frequency response, sensitivity, power handling, impedance, configuration, price, and—crucially—horizontal and vertical dispersion to evaluate sound distribution.Comparison Table
| Speaker Model | Frequency Response | Sensitivity | Power Handling | Impedance | Configuration | Horizontal Dispersion | Vertical Dispersion | Price (approx.) |
|---|---|---|---|---|---|---|---|---|
| Designed Speaker | 34 Hz – 20 kHz (±3 dB) | 86.5–87 dB | 100W RMS | 4Ω (<450 Hz), 8Ω (>450 Hz) | 3-way | ~90° at 1 kHz, ~60° at 10 kHz | ~40° at 1 kHz, ~30° at 10 kHz | $372 |
| Polk Audio Signature Elite ES15 | ~50 Hz – 20 kHz* | ~88 dB* | N/A | 8Ω* | 2-way | ~90° at 1 kHz, ~60° at 10 kHz* | ~40° at 1 kHz, ~30° at 10 kHz* | $250–$300 |
| ELAC Debut B6.2 | 44 Hz – 20 kHz | 87 dB | 30–120W | 6Ω | 2-way | ~90° at 1 kHz, ~60° at 10 kHz* | ~40° at 1 kHz, ~30° at 10 kHz* | $300 |
| Klipsch R-51M | 62 Hz – 21 kHz | 93 dB | 85W RMS | 8Ω | 2-way | ~90° at 1 kHz, ~60° at 10 kHz (horn-loaded) | ~40° at 1 kHz, ~30° at 10 kHz | $250 |
| KEF Q150 | 51 Hz – 28 kHz | 86 dB | 10–100W | 8Ω | 2-way (Uni-Q) | ~90° at 1 kHz, ~90° at 10 kHz (coaxial) | ~90° at 1 kHz, ~90° at 10 kHz (coaxial) | $500 |
| Triangle Borea BR03 | ~45 Hz – 20 kHz* | 87.3 dB | 30–120W | 8Ω* | 2-way | ~90° at 1 kHz, ~60° at 10 kHz* | ~40° at 1 kHz, ~30° at 10 kHz* | $500–$600 |
*Estimated based on typical specifications w
Performance Analysis
Bass Extension (Frequency Response)
The designed speaker’s 34 Hz bass extension outperforms all comparison models. The ELAC B6.2 (44 Hz) and Triangle BR03 (~45 Hz) are closest, while the Polk ES15 (~50 Hz), KEF Q150 (51 Hz), and Klipsch R-51M (62 Hz) have higher roll-off points, making the designed speaker better for deep bass without a subwoofer.Sensitivity
The Klipsch R-51M leads with 93 dB, ideal for louder output with less power. The designed speaker’s 86.5–87 dB aligns with the ELAC B6.2 (87 dB), KEF Q150 (86 dB), and Triangle BR03 (87.3 dB), while the Polk ES15 is estimated at ~88 dB. It’s sufficient for most home setups.Power Handling
The designed speaker’s 100W RMS matches or exceeds most competitors. The Klipsch R-51M is rated at 85W RMS, and the KEF Q150 handles up to 100W, while the ELAC B6.2 and Triangle BR03 support up to 120W amplifiers.Impedance
The designed speaker’s hybrid impedance (4 Ω below 450 Hz, 8 Ω above) may demand an amplifier capable of handling 4 Ω loads, unlike the 8 Ω or 6 Ω ratings of the comparison models, which are easier to drive.Configuration
The 3-way design provides dedicated drivers for bass, midrange, and treble, potentially offering better frequency separation than the 2-way configurations of the comparison speakers.Dispersion (Horizontal and Vertical)
- Horizontal Dispersion: The designed speaker offers ~90° at 1 kHz, narrowing to ~60° at 10 kHz, similar to most 2-way speakers like the Polk ES15, ELAC B6.2, and Triangle BR03. The Klipsch R-51M’s horn-loaded tweeter may enhance high-frequency dispersion slightly. The KEF Q150, with its coaxial Uni-Q driver, maintains ~90° across frequencies, offering a wider sweet spot.
- Vertical Dispersion: The designed speaker’s vertical dispersion is ~40° at 1 kHz and ~30° at 10 kHz, typical for vertically aligned drivers. The KEF Q150 excels with ~90° vertical dispersion due to its coaxial design, making it less sensitive to listener height. The other models align with the designed speaker’s narrower vertical spread. The slanted baffle in the designed speaker reduces some vertical phase issues, but listener height remains a factor.
Price
At $372 per pair, the designed speaker competes with the Polk ES15 ($250–$300), ELAC B6.2 ($300), and Klipsch R-51M ($250), while undercutting the KEF Q150 ($500) and Triangle BR03 ($500–$600). Its DIY cost excludes labor, enhancing its value.Conclusion
This custom 3-way bookshelf speaker pair delivers exceptional performance for its price, with superior bass extension (34 Hz), a flat frequency response, and a 3-way design enhancing midrange clarity. Its horizontal dispersion matches most competitors, while its narrower vertical dispersion requires careful positioning, unlike the KEF Q150’s coaxial advantage. Compared to models like the Polk ES15, ELAC B6.2, and Klipsch R-51M, it offers better low-end performance and detail, and its price undercuts higher-end options like the KEF Q150 and Triangle BR03. For DIY enthusiasts seeking high-fidelity sound on a budget, this design is a standout choice.
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It fails because the price is higher (371$) but the computations are ok,
Some thoughts about the Klipsch R51 which might incorporate double woofers ( or not) but that 93 dB sensitivity data must come from the major efficient horn loaded tweeter.
The conclusion "This custom 3-way bookshelf speaker pair delivers exceptional performance for its price, with superior bass extension (34 Hz)" is pure fiction, but entertaining
Pure hokum. Design network is not from VituixCad. Off the shelf xover utilized, and there is a better and cheaper woofer in the SD215A-88, the mid and tweeter could be improved for the task too. The Dayton Titanium is not a smooth response tweeter, the ND25FA would be better, and I would use the PC105 over the RS100 for pure midrange duty.
This writeup wreaks of less than half informed AI mumbo jumbo.
This writeup wreaks of less than half informed AI mumbo jumbo.
It's apparently a new forum game where the OP posts an AI design, and wants people that can actually design speakers, to tell him it sucks. His thread from a week ago was closed by the mods.
In case anyone missed it, that's not an off the shelf x-over as he stated either, so cost would be considerably higher. I doubt that he has read the schematic that's posted. Even Spock would round off some values I think. Other errors are there too. Hope no one buys into this nonsense.
In case anyone missed it, that's not an off the shelf x-over as he stated either, so cost would be considerably higher. I doubt that he has read the schematic that's posted. Even Spock would round off some values I think. Other errors are there too. Hope no one buys into this nonsense.
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Ah ah I thought it had learned to do the associations and entered the software programs but, no!
Mods should put AI in the Sin Bin for a week expecting then a better behavior when out
Mods should put AI in the Sin Bin for a week expecting then a better behavior when out
More than anything, I dislike the hype. The attempt to claim superiority over commercial designs is sad.
VituixCAD is mentioned four times in the first post. But the only screenshots I see are from Boxsim 2. 🤔
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Indeed that is the enthusiasm that is often found in the presentation of a creation. Naive is the word for it
We'll be waiting a while then. 😉
Back on the ChatGPT generated twaddle again, I see. With (as has been noted) VituixCAD referenced, but Boxsim screenshots added, the one showing the alleged crossover indicating values which have the square root of jack to do with the off-the-shelf Dayton filter claimed. Which, as an aside, I can't find any evidence for the existence of. Perhaps they're hiding it, because of the very peculiar / non-standard values shown. You might almost think they'd come from a rather simplistic running of Boxsim's optimiser.
I fear we're back to how much this sucks -so I'll leave it to the Ant and the Aardvark again:
Back on the ChatGPT generated twaddle again, I see. With (as has been noted) VituixCAD referenced, but Boxsim screenshots added, the one showing the alleged crossover indicating values which have the square root of jack to do with the off-the-shelf Dayton filter claimed. Which, as an aside, I can't find any evidence for the existence of. Perhaps they're hiding it, because of the very peculiar / non-standard values shown. You might almost think they'd come from a rather simplistic running of Boxsim's optimiser.
I fear we're back to how much this sucks -so I'll leave it to the Ant and the Aardvark again:
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What an excellent running gag!
And in terms of running gags why not looking forward for the next thread altogether? Title suggestion: "And now for something completely different"
@ Cal Weldon: And in terms of running gags, there seem to be some work ahead for you. As for me, I already hired my place at the end of the pier.
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If nobody responds and we all wait, this thread will sink down in oblivion. Personally, I wouldn’t mind.
She's going down by the bows cap'n!
What to do while waiting though? We could play Abide With Me? 😉
What to do while waiting though? We could play Abide With Me? 😉
A very healthy response I must say, some its damn good😎 and some say throw out that baby with the birth water 🤣. I am currently working on a technical post, its taking time. Rounding off values is in the BOM. Some suggested driver substitution can be explored, but the design as it is now is quite prime. If baffle slant or midrange compartment is an issue I have plans I plan to post.
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