Pulling in an anechoic chamber — JBL LSR305 worth buying


The frequency response of the Genelec 8030A and JBL LSR305 speakers was measured in an anechoic chamber, and a cost-effective evaluation of the LSR305 was made with a subjective sense of hearing. The concise version concludes: It is worth buying, please read the full text for a detailed version.

Note: At the beginning, the author drew up some Laussian listeners. If you want to see the analysis section, please use the left menu.

Reason for purchase

A few days ago, Aunt Zhang broke the news that the LSR305 was only worth 1199 in Central Asia. In fact, the price was quite stable, but it was directed at Amazon's good reputation and did not hold back a pickpocket. Mainly curious about this 'North American entry monitor sales' value is not worth buying.

Aunt Zhang’s assessment of this speaker is not limited to

About 2,000 yuan a pair of this price, for many of the pursuit of the sound quality but do not want to spend too much budget on the top of the desktop player, attractive. In recent years, domestic and foreign manufacturers have also focused on the field of 4 inches to 5 inches, PreSonus Eris E5, sound Q4P, Q5, sound engine A5+ (beautiful), etc. There is also this pig: JBL LSR305.

Listening view

With regard to the 'listening speakers' category, I only talk about personal understanding: In the entire listening device, the task of the monitoring box is to restore the input signal itself as much as possible, without any modification. In the context of this article, the frequency response is straightened as far as possible. The reason why the classification of 'monitor speakers' is mainly to distinguish it from multimedia speakers. The more used scenarios of multimedia boxes are watching movies, listening to pop music, entertainment environments, trying to please consumers in sound quality and design, and not pursuing straightforward responses.

The other thing is to mention 'listening concept', what is the so-called good voice? Essentially, this is an aesthetic issue. Tolstoy thinks that aesthetics is an inward feeling that cannot be expressed to others in verbal writing; Wigginsmann said that when you see (here is to hear or see and listen to) art you know That's art; Hume thinks. . . It's a far cry from the point of view, and it's a very subjective question as to what is a good voice and what makes you think this is a good voice, but it also requires objective criteria to evaluate. Or let Hume finish: 'You must not confuse two questions: 'I like it or not' and 'it's good or not'. In order to answer the previous question, Lin Lin's loudspeakers are in front of me. If you want to bring them home, you'd better listen to your ears and receive the goods. At the same time, I try to answer the question, 'Is it good'? It is still a question of 'mysticism'.


The main idea of ​​this article is to analyze the frequency response of the LSR305 box itself, and to give a reference to the A/B test results of the students in our group. The laboratory had just bought the 8030A of Zenith (I ordered it specially for the purpose of educating the students in listening), and then the LSR305 that had just got it was moved by me to the anechoic room to make full use of it (test). The test refers to the IEC 60268-5 standard, but this standard is for passive systems, so it is only for reference. Here is a special statement: This article is not a thesis, not very strict, but also ask the gods to lightly spray.

test environment

The entire anechoic room, although my body constitutes a reflector, but basically can ignore the interference of the reflected sound. The test tone is pink noise (I'm pink: equal energy for each octave), the signal acquisition is the sound card of the Fireface UC, and the microphone is B189's 4189. The speaker-to-microphone distance is 1m. The microphone is centered on the tweeter and woofer. Pictured:

The frequency response measurement results are as follows:

Subjective hearing

First of all to apologize: Because I only bought one LSR305 (don't ask me why. The account has only enough money), so there is no evaluation of positioning and positioning in the subjective sense of hearing. . . The source selected 'Mozart: String Serenade - 1. Allegro' and 'My heart will go on', format 320Kpbs MP3, 32-bit floating-point precision. The two music dynamics are considerable, and there aren’t many times. The author thinks that the quality of the two speakers can be better reflected. Decoding or using the Fireface UC, the cable is the line of the XLR Canon head, because it is not a fan of high-end wire. In addition, a personal understanding of the plug: Both boxes are powered speakers with amplifier, the input is a digital signal, in theory, the impact of wire can be ignored.

The listening sequence is to listen to 8030 after listening to 305 first, the subject does not know which speaker is more expensive, but can see the speaker. So this test is not a double-blind test. The evaluation of each individual does not start, and the feelings of the eight hearing-impaired young people are very consistent. Genial 8030: The sound is wide, and the high frequency of the female voice, violin, etc. is clear and bright, and the ears are scratched, which is obviously improved compared to the LSR305. JBL LSR305: The low frequencies seem to be more full, but slightly dragged and the sound field is relatively concentrated. To put it more subjective to feel some: The sound of 8030 really is very natural, just like listening to Dion's singing, the band playing nocturne, enjoy. JBL's voice is also very nice, but it is obviously sent out of the box, with the rendering of the box itself.


From the frequency response curve, the quality of both boxes is excellent. Low-frequency dive to 53Hz accords with the curve given by the official, the curves of the two speakers below 2000 Hz are quite consistent, and the overall range is relatively stable.

Mainly analyze the difference: 50Hz low frequency, 305 sound pressure level is a little higher than 8030 a few decibels, and then quickly disappear, which also confirms the subjective feelings in the '305 low-frequency sense of a little more' results. Near 500 Hz: The 305's response is about 4 decibels lower than that of the 8030. This band corresponds to the lower boundary of the guttural sound and is also the area where men and women are relatively concentrated. This may explain why the 8030 sounds richer and fuller. Another major difference occurred at 2000-3700 Hz. This time there was a major depression in the 8030. Here the author had to apologize again. This depression has a large deviation from the official frequency response curve, and after repeated investigation did not find the problem However, except for this depression, the response of other frequency bands and the official curve are very close. 305 has a smaller bump between 2k and 4k, which is less than the 8030 official curve. After 6000 Hz, the curve of 8030 is interlaced with each other, and after 15K, the honey juice rises, which has no effect on the sound quality.

In order to eliminate the problem of the depression of the 8030 curve, the real box is smoother than the 305, but the difference is visible from the figure. If only from the frequency response curve to determine the two speakers are better than one, first, the measurement accuracy requirements are even higher, and second, the analyst's experience is also very high, it is difficult to see at a glance which curve behind The quality of the speaker is higher.

in conclusion

As mentioned above, the subjective nature of the speakers, the design of the speakers, and the preference of the individual will influence the evaluation of the sound quality of a speaker. This article took 8030 this unit price of 4000 yuan speaker to compare with the price of 305 305 is not to cause pull damage, but to 8030 as a benchmark to evaluate 305 is worth the price back. From the frequency response curve point of view, it is possible to maintain a very close response curve with the 8030. 305 is qualified for the title of “big bowl”. No wonder we can dominate the range of entry monitor speakers for a long time. Subjectively, because everyone listens first to the cheap 305 and then to the 8030, they will all sigh, "Wow, it's better to hear this later." In fact, at the beginning of listening to 305, I thought the sound was still quite good and worthy of this price. Finally talk about the purchase opinions of 305, 305 perennial hot, quality control work has been very stable. The price of each channel is also relatively transparent, Amazon's service bonus of 1199 is a law-abiding price, worry and save. The price on the X treasure is not too low. I think that a brand new one belongs to a good price that can be a second. 305 appearance and calm moderation, interface and cabinet work I use 'qualified' to describe, there is a strong sense of presence on the desktop, a small table or discretion. The author was initially planning to keep it in use, but there was no harm without comparison. After 8030's education, I decided to return it. . If I choose 305, I may go for a cheap second hand; again. . . Save yourself a box with a price of 8030 for yourself.

the above


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