Indigenous Hi-Fi Amplifiers

[Ajitsank]

I just looked at Tekton's page and saw that all their tweeters are flush-mounted..

Category: Monitors

tektondesign.com

Category: Center & Surround Speakers

tektondesign.com

For every company that can be cited as an example for non-flush mounted drivers, I can cite 100 other companies who do take the pains to flush mount drivers because they understand the engineering compromise involved..

Here is a relatively recent video about what Erin had to say about this matter:

The midbass/bass driver flush mounting may be less of an issue (depending on the crossover point) w.r.t high-frequency diffraction.
As I and others have repeated over and over in the past (in this forum), flush mounting is just a small part of the overall design optimization for a small 6.5-inch 2-way kind of speaker. More important aspects involve the overall baffle and cabinet shaping, considering the directivity targets of the design and crossover design. The effect of high-frequency diffraction is commonly seen in frequency response as a series of peaks and dips in the frequency response. However, their probably more audible effect is the screwing up of timing/smearing of imaging compared to a better-designed speaker at relatively high volume levels.

What what level of db would this really be promitent: for information only.

However, their probably more audible effect is the screwing up of timing/smearing of imaging compared to a better-designed speaker at relatively high volume levels.

 

[Vineethkumar01]

Can the edge diffraction of a non flush mounted tweeter be ameliorated by offsetting it such as that done on the Edifier 1280?

https://www.amazon.in/Edifier-R1280T-Bookshelf-Speaker-Brown/dp/B016P9HJIA/ref=asc_df_B016P9HJIA/?tag=googleshopmob-21&linkCode=df0&hvadid=397107752360&hvpos=&hvnetw=g&hvrand=94189018214663870&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9061723&hvtargid=pla-408792870604&psc=1&ext_vrnc=hi

I personally would never recommend that approach as it may or may not help with high-frequency diffraction reduction depending upon a lot of factors, such as the overall directivity of the tweeter and baffle dimensions/edge treatments.
Since the diffraction due to non-flush mounting happens due to the circular boundary formed by the tweeter, the flange around the radiating dome will not get affected much by offsetting the tweeter. However, the diffraction caused by the edges of the baffle can be lessened to the on-axis angle and probably to the listening window angles by offsetting the tweeter location.
Offsetting the driver shifts the angles to which the diffraction effects are observed. So even if the on-axis may look fine in a frequency response measurement, the near or far off-axis curves will probably not look nice due to diffraction. How much of that will be audible will be usecase and placement/room dependent..
Regarding good practices to reduce diffraction, the best way to avoid diffraction is to use an infinite baffle design (drivers flush mounted into wall/large surfaces). It will also help with making a low directivity/wide radiating design if that kind of sound suits one's tastes.
If one wants to go with a narrow baffle and have less diffraction, terminate the waveguide properly on the baffle using larger radius rounding or chamfers starting immediately at the edge of the waveguide like below.

If one wants to go with a direct radiating tweeter and still get less diffraction effects, go with a shaped baffle design like the Taipuu Kero which has rounded chamfers surrounding the tweeter area (This shape has the additional advantage of helping with directivity blending between the mid and direct radiating tweeter in the crossover region)

 

[keith_correa]

Can the edge diffraction of a non flush mounted tweeter be ameliorated by offsetting it such as that done on the Edifier 1280?

https://www.amazon.in/Edifier-R1280T-Bookshelf-Speaker-Brown/dp/B016P9HJIA/ref=asc_df_B016P9HJIA/?tag=googleshopmob-21&linkCode=df0&hvadid=397107752360&hvpos=&hvnetw=g&hvrand=94189018214663870&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9061723&hvtargid=pla-408792870604&psc=1&ext_vrnc=hi

Also, if a tweeter is not flush mounted in a fixed width baffle, you have 2 occurrences of diffraction - 1/ from the transition of the edge of the tweeter flange to the baffle and 2/ from the baffle edge. Also, it has been shown using measurements that even if a tweeter is flush mounted and if there is a 1mm or 2mm gap between the edge of the flange and the baffle, diffraction increases. Now whether all this is audible or not is a different matter altogether.

 

[Kannan]

@Vineethkumar01 i remember that thread which was on a pair of AudioQ, now renamed as IndiQ, speakers where the tweeters were screwed directly on the plane of the front panel and I think so were the woofers. It was a bad design and I remember the thread going north with lots of baseless replies from some members when you pointed out the defeciency without any malice and purely from a technical point of views.
I find that the company has.mow resurrected the design and specifically mentions that the tweeters are flush mounted to minimise diffraction.
It kind of vindicates what you had mentioned in the thread to which many took offense.

 

[keith_correa]

I remember the thread going north...

Just north? It went in ALL directions.

 

[Vineethkumar01]

What what level of db would this really be promitent: for information only.

However, their probably more audible effect is the screwing up of timing/smearing of imaging compared to a better-designed speaker at relatively high volume levels.

It is hard to say exactly at what level all this can be heard because these effects are speaker concept (in terms of directivity) and room placement/treatment dependent, 'person'-dependent etc.
Earl Geddes says the effects were detected even at an SPL level of 80dB. You can read the paper in the following link if you are interested about the study that brought out these kind of observations:

http://www.gedlee.com/Papers/AES06Gedlee_ll.pdf

Testing the audibility of linear phenomena such as reflections and diffraction is easy to do with a pair of neutral headphones. Similar to what Earl Geddes did in the above paper, one can download one's favourite track, convolve it with a filter that models the reflection/diffraction effect (basically variations of comb filters) in software like VituixCAD, export the response as an FIR filter, convolve the music track with the filter using some convolver software like Equalizer Apo and playback. Compare this with the original track and decide for oneself what the difference is and how much can be tolerated. Doing this using headphones are very instructive as it removes the room from the equation, and one can get a sense of reference to what is kind of effect is audible/can be expected, at least the part of it that is tonality related. The next step would be to playback the original track using the speakers and see if one can experience similar variations in sound as before and if imaging is proper etc

 

[liverpool_for_life]

Because some amount of that 'class 10' and 'class 12' physics are needed to understand what is diffraction. among other things..

The irony was oh so delicious, though.

 

[liverpool_for_life]

Wat ij physsichs? I haf heardt of Clash A and Clash D, butt neber heardt of Clash 10 and 12.

Sinceerly,
Audiofool who neber vent to schul.

A little more consideration, please, for folks who might be reading while having their late afternoon/early evening cuppa...

 

[bhooshaniyer]

Until I saw the Indiq review thread few months back, I had no idea that flush mounting of tweeter or not impacted the speaker output in a negative way. I would think of me as a sophisticated user of speakers but this was an eye opener to know that there are so many visually observable features of a speaker that speaks(ahem!) to its performance or design philosophy! Not that this is easy material to read and understand but its humbling to know that its possible for some of us listen to music and talk about designing of speakers at a deep technical level.

 

[samml]

Hi Members,

I am new to this forum and want to share my experience. I had been using a Cambridge Audio Azur 650 A for last 10 years. This was driving custom made 3-way tower speakers made by Kolkata speaker man Kaushik Mitra ( owner of Hertz brand). Just 2 years back I changed these speakers to Tannoy Mercury 3. Had been longing for a power amp but due to budget constraints was not able to leap in. So my search for indigenous PA began. From the forum I came across 3 names- Shaan's Peeceebee, Aniket's DD and Aniket Das's O&B. I spoke to each one of them and trust me all of them are gem of a person as they will patiently hear you out and guide you. But somehow I had to choose one of them and decided to go with O&B. My requirement was a warm sounding PA with 150w@8 ohms each channel with the best possible components. Here Aniket took 2 months time to complete the project and throughout the entire two months he kept updating me about the progress and even shared pics of the components used. Now it's been 3 weeks I am using the PA by pairing the CA Azur 650A as the preamp. The Tannoys are sounding more open and clear at even lower volumes. Aniket has done a great job and with that increased my greed to shell out more on my audio set up as I will need to upgrade the speakers which can tackle the power of the amp.

Can you pls share the website /details of Anikets DD? Thanks

Hi Members,

I am new to this forum and want to share my experience. I had been using a Cambridge Audio Azur 650 A for last 10 years. This was driving custom made 3-way tower speakers made by Kolkata speaker man Kaushik Mitra ( owner of Hertz brand). Just 2 years back I changed these speakers to Tannoy Mercury 3. Had been longing for a power amp but due to budget constraints was not able to leap in. So my search for indigenous PA began. From the forum I came across 3 names- Shaan's Peeceebee, Aniket's DD and Aniket Das's O&B. I spoke to each one of them and trust me all of them are gem of a person as they will patiently hear you out and guide you. But somehow I had to choose one of them and decided to go with O&B. My requirement was a warm sounding PA with 150w@8 ohms each channel with the best possible components. Here Aniket took 2 months time to complete the project and throughout the entire two months he kept updating me about the progress and even shared pics of the components used. Now it's been 3 weeks I am using the PA by pairing the CA Azur 650A as the preamp. The Tannoys are sounding more open and clear at even lower volumes. Aniket has done a great job and with that increased my greed to shell out more on my audio set up as I will need to upgrade the speakers which can tackle the power of the amp.

Can you pls provide the contact details of Aniket's DD?

 

[souban82]

Can you pls provide the contact details of Aniket's DD?

96543 80001