Thanks for gesture. Will let you know when i can come. The speakers are kind of huge and heavy will not fit in my car and hence will need to also think about logistics. Will let you know if decided.
A new Linear TL Floor Standers for my next upgrade to 845 tubes
- Thread starter Hari Iyer
- Start date
Thanks for gesture. Will let you know when i can come. The speakers are kind of huge and heavy will not fit in my car and hence will need to also think about logistics. Will let you know if decided.
kapvin
Well-Known Member
Don't think twice. I am sure they will fit in your car if you put the seat down. Mine are huge and they do. Plus it is less than 4km to my house.
If your car is really too small then here is a bonus offer, I will bring mine.
Don't be resistant to measuring your speakers. It will validate the integrity of your design. Or can only help improve your design even more.
Thanks for this great offer, as planned we will meet today at 3PM and start our measurements. The speakers would have played a total of around 25hrs till now.
So the much awaited Dared VP-300B arrived this week on Wednesday.
I connected them and played some of my reference music and listend to them and here are my observations,
- inital 30 min the mid-range were quite muddy and cluttered. Reason could be no breakin of the tubes and tube was not warmed up adequately. After 30 min the mid sounded much rounded and smooth with the harshenss vanishing.
- lows were not very tight due to the simulation issue with my speakers. The lows were overpowering the mids and the highs and masking them a bit.
- highs were initially grainy but latter sounded crisp and detailed after the warm up.
I am not sure how many hours of breakin i am supposed to expect with the 300Bs. May be our FM Prem, Bagwan, captRajesh could throw some more light on this.
This is going to be my first tube experience after the Metz tube radio ( the last i heard them was when i was 8 year old and i had a B&W Weston tube TV with the audio section using tubes there till 1985). and do not know what to expect in terms of sound stage and dynamics.
For sure they sound way ahead than the Sony's and the Denon's
I connected them and played some of my reference music and listend to them and here are my observations,
- inital 30 min the mid-range were quite muddy and cluttered. Reason could be no breakin of the tubes and tube was not warmed up adequately. After 30 min the mid sounded much rounded and smooth with the harshenss vanishing.
- lows were not very tight due to the simulation issue with my speakers. The lows were overpowering the mids and the highs and masking them a bit.
- highs were initially grainy but latter sounded crisp and detailed after the warm up.
I am not sure how many hours of breakin i am supposed to expect with the 300Bs. May be our FM Prem, Bagwan, captRajesh could throw some more light on this.
This is going to be my first tube experience after the Metz tube radio ( the last i heard them was when i was 8 year old and i had a B&W Weston tube TV with the audio section using tubes there till 1985). and do not know what to expect in terms of sound stage and dynamics.
For sure they sound way ahead than the Sony's and the Denon's
keith_correa
Well-Known Member
Yes, I understand that. I was just confused by this statement:
Was wondering how you could listen if you have not implemented it.
All the best for the measurements today. Would appreciate it if you or kapvin can provide details on how you measured, the measurement equipment etc. It would aid in me learning and for all FMs interested in this sort of thing.
I modified the speakers with this current simulation and will be measuring them today at Kapvin's home in the evening. This response has a better balance between low's, mids and highs and has been voiced considering my listening room constraints.
What i will be looking for in the measurements is whether it gives the above response or the below response,
or a flat response considering the room anomalies and the final acoustic flat response in the far field,
Will post them later
What i will be looking for in the measurements is whether it gives the above response or the below response,
or a flat response considering the room anomalies and the final acoustic flat response in the far field,
Will post them later
I have build the spkrs around a month ago and have been tweaking them after listening to them. They have undergone 4 rounds of tweaking and the last tweaking will be the 5th one. Hope the meaurements now agree with the simulations.
What i believe that with simulations you can only balance the electrical response / behaviour of the driver + crossover.
With actual measurements the acoustical behaviour of the speakers + room can play a major role and hence the simulations and measuremnts cannot be identical. May be the anechoic response will be similar to the simulations but not the far field measurements.
Yes, will post the measurements later in the day.
keith_correa
Well-Known Member
I would be very interested in you or kapvin detailing the process of taking measurements.
Too bad I saw this thread only now. I need to turn the volume of the VP845 to 12 o'clock to drive my 89 dB sensitive Arista speakers for room filling sound.
I'm not sure if the comparatively puny 9 Watt 300B amplifier would have enough juice to drive your 90 dB speakers and also have enough head room in the reserve.
Though it was sounding good right out of the box, my amp required about 25 to 40 hours to reach to the super state that it is now in.
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I am finding my speakers too loud even for the 12 o'clock position and now have reduced them to 11 o'clock position. I dont think the 9w + 9w is less considering that and the main reason i did not go for the 845 was it becomes too too hot and the additional power would have been lost as heat anyways.
I will be designing my own pre-amps to use with the 300Bs and this will give them additiional head-room.
The amp do sounds good and now would have played them for max 8 hrs.
Here are the first images of the amp,
keith_correa
Well-Known Member
OT, but I see that there is a single PS powering both the amps. I always thought monoblocks were independently powered.
kapvin
Well-Known Member
9w+9w would mean about 103 db with 90db/w speakers.
2 technical comments on hari's speakers
1. They are very efficient indeed. We did not measure output at 2.83v, but I played my bookshelves which are about 86db/w on the test rig after hari left and they are noticeably softer. I'd estimate 91-2 db/w in the midrange. Also in hari's house there is a lot help from room gain.
2. The final speaker impedance curve (and consequent electrical phase) were extraordinarily flat apart from the impedance peak of the woofer. Not seen such a flat curve almost ever before. This would present a very benign load on any amplifier. A lot of effort clearly went into the making of the crossover. Well done.
Rest of the info.. It's upto hari to share or discuss.
What about head room for the transients?
kapvin
Well-Known Member
EMM-6 Calibrated.
true that.
but that would allow average listening levels of about 85dB, given the program material that most tube owners would gravitate towards.
anyway it's diametrically opposite to my approach, which says that you should always err on the side of excess as far as good clean watts are concerned
Over the past couple of weeks, I have done the following modifications with the speaker,
1. Changed the Peerless kevlar woofer to Tang Bang Polyproplene woofer. The size of the woofer was ditto and hence there was not much challenge to fit them. The resonance of both woofers are also similar and hence no major modification to the box other than the damping coefficient.
2. Changed the Peerless Alunimium Dome to Vifa Silk Dome tweeter. The box needed minor modification to fit the new tweeter but was a minor modification for an hour for the carpenter.
3. Modified the crossover as per the drivers and changed the cross-over freq to 1930Hz as per the wavelength of the woofer and tweeter distance.
After these modification i found a significant improvement over the sound stage, image depth, spatial balance and intimacy in the vocals and the mid-range. The woofer bas is very tight and extended and tweeter quite mellow and soft to listen too. I must have completed around 15 hrs of listening session with this modificationa and must say now that I am quite happy with the outcome.
I did some expriments with the speaker placement, toe-in trying to get the best delay in the reflections in my small room. I tried adding absorbents on the floor and all reflecting surface to find out where the early reflections were impacting the imaging. When the room was filled with such material my wife got furious and removed all of them at one shot and i discovered that its more to do with the room than the cross-over. Since keeping these materials as it is was not practical for the room decor, i thought of doing the same by modifying the cross-over by attenuating the freq which i need to attenuate to bring the effect of the absorbers / diffusers. Now i am getting the same effect as if i have added the materials to the room.
The overall sound stage is now very balanced considering this aspect of the room. I am not sure how the speakers may sound if placed else where, but only exprimentation can conclude my findings. If the room is similar to what i have then there need not be much change. Now i again feel more that speakers are to be designed with the room / furntiures / reflections / position kept in mind. No wonder why many high-end speakers sometime sound very medicore in some room environments. Also now keep wondering now how a Bose 5.1 sounds quite good in their demo room and pathetic at our homes.
1. Changed the Peerless kevlar woofer to Tang Bang Polyproplene woofer. The size of the woofer was ditto and hence there was not much challenge to fit them. The resonance of both woofers are also similar and hence no major modification to the box other than the damping coefficient.
2. Changed the Peerless Alunimium Dome to Vifa Silk Dome tweeter. The box needed minor modification to fit the new tweeter but was a minor modification for an hour for the carpenter.
3. Modified the crossover as per the drivers and changed the cross-over freq to 1930Hz as per the wavelength of the woofer and tweeter distance.
After these modification i found a significant improvement over the sound stage, image depth, spatial balance and intimacy in the vocals and the mid-range. The woofer bas is very tight and extended and tweeter quite mellow and soft to listen too. I must have completed around 15 hrs of listening session with this modificationa and must say now that I am quite happy with the outcome.
I did some expriments with the speaker placement, toe-in trying to get the best delay in the reflections in my small room. I tried adding absorbents on the floor and all reflecting surface to find out where the early reflections were impacting the imaging. When the room was filled with such material my wife got furious and removed all of them at one shot and i discovered that its more to do with the room than the cross-over. Since keeping these materials as it is was not practical for the room decor, i thought of doing the same by modifying the cross-over by attenuating the freq which i need to attenuate to bring the effect of the absorbers / diffusers. Now i am getting the same effect as if i have added the materials to the room.
The overall sound stage is now very balanced considering this aspect of the room. I am not sure how the speakers may sound if placed else where, but only exprimentation can conclude my findings. If the room is similar to what i have then there need not be much change. Now i again feel more that speakers are to be designed with the room / furntiures / reflections / position kept in mind. No wonder why many high-end speakers sometime sound very medicore in some room environments. Also now keep wondering now how a Bose 5.1 sounds quite good in their demo room and pathetic at our homes.
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After two months of listening, tweaking of the speakers with various sources - CD, Tape, Tuner, TT with the room and placement, finally have settled for this electrical response.
The cross-over seems to be theoritically perfect with flat impedance and impedance-phase and offers a near resistive load to the amplifier like a single driver speaker.
The dynamics are very accurate, bass tight, midrange free and open, highs very crisp and mellow now. Am able to get finer details in the music with excellent transient response. The bass decay is also excellent with superb image depth and spaciousness. The vocals are very intimate making the presence felt and quite involving. Overall i can now say that i have now achieved what i intended to with the TB and Vifa combination with my Advancce TL.
I have still retained the first order filter with some tank circuit for the tweeter as its mechincal Q is little on the higher side. This made me to shift the crossover from the earlier 1930Hz to the more reasonable 3KHz. This has to some extent compomised on the spacing between the drivers but is not noticable in the centre imaging. The Tangband wider bandwith allowed me this modification with ease without any noticable cone breakup issues at its roll-off.
As i have now completed the prototype crossover will now go ahead with repalcing the component with good quality components. Have couple of questions for FM,
1. What resistors to use - wire wound, Metal Oxide, Film (currently WW)
2. What capacitor to use - Polyester, Film, Foil (Currently Polyester & Non-Polar)
3. What guage inductor - 14, 16? - Currently 18SWG.
The cross-over seems to be theoritically perfect with flat impedance and impedance-phase and offers a near resistive load to the amplifier like a single driver speaker.
The dynamics are very accurate, bass tight, midrange free and open, highs very crisp and mellow now. Am able to get finer details in the music with excellent transient response. The bass decay is also excellent with superb image depth and spaciousness. The vocals are very intimate making the presence felt and quite involving. Overall i can now say that i have now achieved what i intended to with the TB and Vifa combination with my Advancce TL.
I have still retained the first order filter with some tank circuit for the tweeter as its mechincal Q is little on the higher side. This made me to shift the crossover from the earlier 1930Hz to the more reasonable 3KHz. This has to some extent compomised on the spacing between the drivers but is not noticable in the centre imaging. The Tangband wider bandwith allowed me this modification with ease without any noticable cone breakup issues at its roll-off.
As i have now completed the prototype crossover will now go ahead with repalcing the component with good quality components. Have couple of questions for FM,
1. What resistors to use - wire wound, Metal Oxide, Film (currently WW)
2. What capacitor to use - Polyester, Film, Foil (Currently Polyester & Non-Polar)
3. What guage inductor - 14, 16? - Currently 18SWG.
M
mpw
Guest
hari,
use the best money ( read budget + stretch @20% ) can buy.
you seem to have enough knowledge to make the choices.
mpw
use the best money ( read budget + stretch @20% ) can buy.
you seem to have enough knowledge to make the choices.
mpw
Nice Speakers Hari, Glad to see the finish is much better than previous versions.
Though i don't like passive XO because of obvious reasons, but let me give you some inputs on your queries.
1. Preferably Strip Metal Film. If you don't have access to such type then use inverse-parallel connected wire wound resistors in order to decrease their non-linear inductance. Check with Resistors India - Manufacturer of India - HTR India , they make nice strip metal film resistors also, Try HMVL series.
2. Parallel Films in stacked construction preferably. For example if you need 1uF value, try to use 10 X 0.1uF types. This way you will cut down the non-linear distortion happening at high current ripple through the capacitor. Go with EPCOS for Stacked Film.
3. If your power rating of speakers is less than 300W, use any gauge from 15 to 17 just to cut down the DCR. Putting more thicker gauge won't do any good because of combined back-emf of driver and XO will not let the damping factor available at amplifier side to get fully utilized. If budget permits, try Litz Wire for inductors, it will considerably cut down the skin resistance.
Cheers,
Kanwar
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