Dismantling Wharfedale Diamond 8.2 speakers

[vivek.saikia]

Finally, the honeymoon period was over with my Wharfedale 8.2 speakers. The initial excitement of the "HiFi" sound was now settled down and I had started to notice some artifacts in the sound which was casuing some concerns to me. The sound was not so pleasing for some kind of music and it started to ache.....right in my heart.
I was on the verge of ending my relationship with these speakers and had almost made up my mind for a divorce with them. I knew that the upgrade bug would bite me soon....but so soon! I was devastated! I even worried, what would I say to all those friends to whom I bragged about my new speakers, leaving no chance of belittling their Sony, Mony, Tonies. This was really getting hard on me.

The problem with these speakers was, what is inherent to any small bookshelf speaker - cabinet resonance. The sound output was not linear and there was a bump in the lower mid frequency due to the standing waves (maybe this is the reason why they designed the super curvy bodies for the wharfy 9 series). This was coloring the sound output. The soundstage was not as wide and deep as I per my liking and the speaker didn't quite "dissappeared". Rather they very arrogantly made aware their presence.
The high frequency sound was quite clear and airy. Though they too had the tendency to become strident if improperly paired with a bright amp but with NAD, they were perfect. Oh, I am so much in love with my NAD amp.

Ok, back to the track. So, the ground reality was that I was not happy with the sound from the Wharfy 8.2s. I even though of retrofitting some solutions to set the things right.

A few things which I thought as retrofittng measures were:

1. Pairing the speakers with a subwoofer, so as to overwhelm the midbass boom by strong bass. Bad idea, as I was going to further colour the sound.
Rejected.
2. Posting an ad in the HiFiVision "For sale by owner" section for speaker sale
3. Desolating the path of HiFi setups and moving into personal audio realm. Thought of buying a Grado headphone paired with a Creek Audio headphone amp.

I am happy that I didn't choose any of the above and relied on my DIY'er instincts.
So, from here goes the happy story.

As a last resort, I thought of trying my tried and tested DIY speaker mod.....stuffing!!

What followed, let the pictures speak for themselves.



The inside of the speaker was filled with a polyfill layer but only at three sides leaving much room for improvement/stuffing.




The two way crossover was really doing it's duty well. The high frequency was crystal clear and soft.



The tweeters were not a happy site though. I was expecting a much bigger motor for the tweeters, specially given the fact that these are bi-wirable speakers. It's not that I am complaining about the sound quality of the tweeters. They are quite crisp and quite airy; and the sound gels quite well with the woofer. It's just their dimensions, which is not pleasing to eyes.



Then followed what had to follow. Generous stuffing of the cabinet. I made sure that the every corner of the cabinet is tightly stuffed leaving some space for airflow through the port. All the inside walls of the cabinet was covered with polyfill fibre. Again an old pillow was sacrificed.





After the stuffing was done I screwed back the front baffle and it was now the moment of truth. Played some music which had some inherent midbass boom due to bad recording (Enrique ).

I was never was so pleasantly surprised before!! The sound was something which I had always longed for! The midbass boom was gone. The sound was no longer boxy and the soundstage was suddenly much wider. There was great amount of depth in the music.
The sound from the speakers were now giving illusion as if some big floorstanders are singing. Who needs a subwoofer now!! No more fatigue due to boominess. The entire sound signature of the speakers changed.....for better......much much better. I am a happy man now. I am happy that I undertook this desicision to mod the speaker. Now I have a great sounding system.

Finally some gyaan from my side, If you notice even a slight amount of boxiness or resonance from your speakers, then stuff them. It really works!!

Happy Stuffing!hyeah:

Cheers!
Vivek

 

[neeraj]

Great Surgeon Dr. vivek saikia with great Gyaan

hyeah:hyeah:

 

[vivek.saikia]

Great Surgeon Dr. vivek saikia with great Gyaan

hyeah:hyeah:

He he.......It's just the DIY'er inside me trying to sprout out at the slightest chance

 

[neeraj]

Hi Vivek you just recalled my childhood ADDA near Shilpukhuri in Guwahati.
There was a Gentlemen Called JOY da Near green Velly Service station in Shilpukhuri. He used to make some decent sounding speakers & Guitars.
I have seen same OPERATIONS over there.

 

[sam_sarna]

Great Stuff mate,

You have inspired me to be a doctor for my mission 32i floorstanders..:yahoo:

cheer's

Sam Sarna

 

[gobble]

Finally, the honeymoon period was over with my Wharfedale 8.2 speakers. The initial excitement of the "HiFi" sound was now settled down and I had started to notice some artifacts in the sound which was casuing some concerns to me. The sound was not so pleasing for some kind of music and it started to ache.....right in my heart.
....

The problem with these speakers was, what is inherent to any small bookshelf speaker - cabinet resonance. The sound output was not linear and there was a bump in the lower mid frequency due to the standing waves (maybe this is the reason why they designed the super curvy bodies for the wharfy 9 series). This was coloring the sound output. The soundstage was not as wide and deep as I per my liking and the speaker didn't quite "dissappeared". Rather they very arrogantly made aware their presence.
The high frequency sound was quite clear and airy. Though they too had the tendency to become strident if improperly paired with a bright amp but with NAD, they were perfect. Oh, I am so much in love with my NAD amp.
A few things which I thought as retrofittng measures were:

1. Pairing the speakers with a subwoofer, so as to overwhelm the midbass boom by strong bass. Bad idea, as I was going to further colour the sound.
Rejected.
2. Posting an ad in the HiFiVision "For sale by owner" section for speaker sale
3. Desolating the path of HiFi setups and moving into personal audio realm. Thought of buying a Grado headphone paired with a Creek Audio headphone amp.

I am happy that I didn't choose any of the above and relied on my DIY'er instincts.
So, from here goes the happy story.

What you've written about the 8.2s is Exactly what I would have written about the 9.2s starting form the initial experience to the eventual disappointment about the resonances and speaker not disappearing.

Except that I actually like the lower mids very much and the way mridangam and tabla sounds on these - over my Audire Callstoe fullrangers costing more than twice as much.

However I would like to inform you that the 9.2s are worse than the 8.2s. at least the 8.2s sound open and airy. the 9.2 do not. but the bass is deeper in 9.2 than the 8.2.

My 9.2s are in the box since a year, but I will now copy your hack and use it for the TV system with the Linuxguru's myRef Gainclone amp in the long run for movie watching. Thanks for the tip. (The thank you button is missing?)

You observations were spot on though.

--G0bble

 

[vivek.saikia]

This tweak really paid me off well and my latest tweak of adding a horn (waveguide??) to the tweeter is like two steps forward towards the sound I long for. Only thing I need to worry about is the looks. How to attain that WAF with the horns still on, is the question.

 

[vasishta.sushant]

Terrific job.

I did a similar thing on my JVC RX900s and can't really tell how good they sound now.

Would love to do it on my polk tsi300s

 

[prasun.gera]

This would work only for ported speakers right? Essentially you are absorbing more sound waves than earlier, or delaying them before the reflection reaches the port, and hence the spike from your port is subdued. I opened up my computer speakers (klipsch promedia 2.1) to check, and found that there is some amount of polyfill in them too. They aren't ported though. What does polyfill achieve there? Apart from possibly dampening the vibrations of the speakers themselves ? In other words, would messing around with the amount of polyfill make them sound any different?

 

[jk_chaos]

Just awesome stuff!!

 

[vivek.saikia]

This would work only for ported speakers right? Essentially you are absorbing more sound waves than earlier, or delaying them before the reflection reaches the port, and hence the spike from your port is subdued. I opened up my computer speakers (klipsch promedia 2.1) to check, and found that there is some amount of polyfill in them too. They aren't ported though. What does polyfill achieve there? Apart from possibly dampening the vibrations of the speakers themselves ? In other words, would messing around with the amount of polyfill make them sound any different?

Poly-fill can be used to make an enclosure seem slightly larger. It does this by slowing the movement of the air in the enclosure. This, in effect, smoothes the frequency response of the woofer's output and slightly improves its low frequency extension. It is applicable for both ported and closed enclosures.

What I have seen in the mass produced speakers is that they compromise on the amount of stuffing (if in case there is any) and this is when you can wear your DIY'er gloves. But the amount of polyfill density has to be fine tuned as per your requirements and In my case it was a hit and trial case. Too less or too much may produce some adverse effect on the sound quality. You may have to stuff the cabinet and then listen to it and then adjust the polyfill density. This cycle may repeat many times until you reach till that desired sound quality.

 

[baijuxavior]

Hats off to vivek.:clapping:

You got the attention and acclamation you deserved after one year. For this you should give a big thanks to neeraj.

 

[vivek.saikia]

Hats off to vivek.:clapping:

You got the attention and acclamation you deserved after one year. For this you should give a big thanks to neeraj.

Thanks Neeraj

BTW, the intention of starting this thread was to share my success story with others so that everyone can gain from it.

 

[prasun.gera]

Poly-fill can be used to make an enclosure seem slightly larger. It does this by slowing the movement of the air in the enclosure. This, in effect, smoothes the frequency response of the woofer's output and slightly improves its low frequency extension. It is applicable for both ported and closed enclosures.

What I have seen in the mass produced speakers is that they compromise on the amount of stuffing (if in case there is any) and this is when you can wear your DIY'er gloves. But the amount of polyfill density has to be fine tuned as per your requirements and In my case it was a hit and trial case. Too less or too much may produce some adverse effect on the sound quality. You may have to stuff the cabinet and then listen to it and then adjust the polyfill density. This cycle may repeat many times until you reach till that desired sound quality.

And where can I get 'polyfill' from? I don't have any old pillows to sacrifice, and even the ones that I have have cotton in them.

 

[vivek.saikia]

And where can I get 'polyfill' from? I don't have any old pillows to sacrifice, and even the ones that I have have cotton in them.

Buy/Borrow/Steal

 

[neeraj]

Thanks Neeraj

Your Welcome.

Hey vivek after all your hard work is appreciated hyeah:
But you cant say it takes a long time of ONE YEAR as several peoples thanked you

 

[magma]

vivek

you probably like the sound now. No doubting that

but what you have done ( by increasing the polyfill/dacron) is basically changed the enclosure characteristics (something contrary to what the original designer had envisaged when these speakers were designed and tested)

im pretty sure the mids have changed.Debatable for the better or worse ( though you have found what your looking for at the lower freq spectrum im pretty sure something is lost in the mids and upper mids)

There is another easier way to remove the boom (extended bass notes ) if you do not like the way it sounds
Stuff an old sock into the port ( some speakers even provide port fillers for this purpose keeping in mind different audiences)
This tweak doesnt change characteristics of the speaker mids


however i do encourage and respect your DIY route.You always learn something.
Keep it up.

 

[omishra]

+1 to magma;

Even I have done it without filling anything to my DIY ported BS speakers. I used dual foam tape & covered it all over the inner surfaces of box. Then took bubble wrap sheet which is used for packing material. Plain side of fine bubble wrap pasted over exposed surface of dual tape. Purpose of this work, to keep intact the internal volume of the box plus cancel standing waves inside the box, if any. Dual foam tape material absorbs the low frequency sound waves while bubble wrap acts towards mids. Waves will not reflect from surface of inner wall of the box. Same time port is in action, resonating with designed frequency with volume of air, which in turn in tune with driver.

I used 1KHz buzzer for testing. Removed speaker driver from baffle and sealed ports temporarily. Listen how buzzer sounds outside the box same way it should sound inside the box when inserted from speaker opening. No reverberation and change of pitch. Stop overdoing it once you deadened the walls enough.

Now result is definitely I liked.

 

[omishra]

And where can I get 'polyfill' from? I don't have any old pillows to sacrifice, and even the ones that I have have cotton in them.

In place of this you can use glass wool (handle with proper hand care, dangerous for respiratory system, if inhaled and skin). This glass wool can be availed from AC/refrigeration engineers. Keep it as complete as possible without breaking. Take some loose cotton mesh like 'mosquito net' and cover this filling of glass wool so that it can not come out from ports etc. Usually I prefer fixing this to INNER walls of subwoofer like below -

I don't have photo's but provide at next work completion.

1. Attach one end of 3 pieces of cotton strings (each of max length box edge meeting at that corner), in INNER corner with Feviquick adhesive (quick drying & hard bonding).
2. Now apply Fevicol to inner surface, here and there.
3. Place 2-3 inch layer of glass wool over that Fevicol. Keep strings out.
4. Place mesh of thin cloth (you get in Ladies general stores which they use for covering backside of Jari-wala design of Sarri, Rs.10/sq.meter)
5. Now tie this layer with previously attached string from opposite corners over than covered surface. For one surface, one string from each corner is used. This is similar way you pack cloths in suitcase.

Repeat this for all surfaces. This won't rattle but keep glass wool safe and secure for its intended purpose. No plastic/nylon used.

I never done anything to baffle plate though.

 

[doors666]

Those of you that are adventurous and want to go to the next step, you can try a couple of more things. Apart from stuffing, the next thing the manufacturer's skimp on is the cabinet. Most of the cabs are made of cheap thin stuff. Anything less than 3/4" (apart from a very small bookshelf or satellites) is not enough. You can add batten braces to the cabinets. See the link below for whats a batten brace.

DIY Audio Speaker Box Building FAQ - Tutorial

If you think the cabinet is leaky, you can use hot glue to seal the edges. Do it from inside due to obvious reasons. Cheap hot glue gun costs less than 200/- and each stick is less than 10/-. This is such a useful item in the household that you will end up using it for a million other things.