Full Range Standmount using Boston HQ48414P driver

[jls001]

I am going to remove the front baffle from box and listen to it just as an open baffle.

You can also try the JE Labs OB:

jelabsarch.blogspot.in/2012/06/open-baffle.html?m=1

 

[linuxguru]

Over more listening, I am realizing that the sound has a strong electric guitar-like character as if this is a guitar amp monitor. So earlier when I mentioned some songs sound more balanced than other, I think it is the frequency range between 2k to 5k which is the problem.

This may have more to do with the source, especially if it is from an MP3 player or low-end CDP. Also check your line-level cables (try out a few).

The more I read about FR drivers, the more I hear that shout is a common problem and a BSC/notch filter/Zobel network is the solution. So I might look into it more.

Midrange shout can be tamed by BSC, but at the cost of a few dB in sensitivity. Polyfill is generally a less-intrusive way to reduce it, but it can muffle the lows and lower-mids.

 

[accord]

So I have removed all the polyfill and there is very slight increase in boxiness (which is negative) but there is also a noticeable increase in the full bodied character of the sound (which is positive). It does seem to have reduced the shoutyness a bit but ever so slightly. I am going to put back 2 layers of polyfill to confirm this.

Over more listening, I am realizing that the sound has a strong electric guitar-like character as if this is a guitar amp monitor. So earlier when I mentioned some songs sound more balanced than other, I think it is the frequency range between 2k to 5k which is the problem.

The more I read about FR drivers, the more I hear that shout is a common problem and a BSC/notch filter/Zobel network is the solution. So I might look into it more.

I am also going to do another experiment. I am going to remove the front baffle from box and listen to it just as an open baffle. The idea is that if there is nothing much I can do to improve the bass in the box (which is also important to make this a listenable speaker), then I will convert the box into a bass module by adding a woofer and low pass filter to cut 100Hz and above. And fix the open baffle with the FR on top and give it mid and high duties with a BSC to even out the mid-high response. Any thoughts?

Hi Aashish, Congrats dear, i am also in the same situation as you are in. Did you find any solution of that problem (shoutyness) ? My issue is i have -00 knowledge in DIY speakers and want to create a good pair of speakers for soft music. As of now i have pioneer fs as main speakers bass is super but mid is not satisfactory. Can you or your DIY professional friend help me out in this. Can we meet on this? hyeah:

 

[kartick]

Hey Ashish, checked this thread today, so thought should share my experience here. About a couple of years back I had picked up a couple of the same drivers as yours but those were still Philips badged. Those were NOS which I salvaged from a shop that was closing. The guy still charged me a premium labeling those as vintage but the condition those were in, it was hard to pass. Anyway, price is not the point.

Later, I had gotten those measured for their Thiel/Small parameters and went to calculate the cabinet dimensions. Wanted to go the simple route so just went for a sealed enclosure box. The volume required to obtain a relatively flat frequency response for a sealed enclosure was 35 cubic liters. If I was going even to double the volume (45 or 60 cubic liters), it wasn't making any significant changes to the linearity of the FR. So I decided to stick with the minimum stable volume required for the cab, i.e. 35 cubic liters, in the interest of money and real estate that these would occupy.

I will post some pictures later. So coming to sonic characteristics now. Upon using multiple amplifiers (both tube & solid state), my overall impression was that these gave excellent Mids. Though a little crass (what we are calling 'shouty' here). However, considering how much these cost, if paired with a mellow amplifier, these are insane for the vocal reproduction capability. Has a lot of air around the voices and makes it good for watching movies. They lack bass, for obvious reasons. They were not meant to go that low. I feel, these would not be sufficient if one is building a balanced speaker. Can act good for a 2.1 setup or also what I have found workable is that if these can be used in parallel with another speaker which can go low, these accentuate the mids very well. After checking your thread, I tried this parallel configuration and I am very happy. It was just an experiment.

When I was trying to fine tune my setup for my Fostex drivers, which also can feel a little shouty at times. I got a zobel network sort of thing made. It works well for the Fostex drivers. I can try it with the Philips drivers as well. Although, it is not meant for these drivers but I can try, wont do any harm to the drivers.

Once your build is complete, we can also get together sometime and try out these things. Maybe FM Accord might also join us.

Hope this helps.

 

[tnvijay]

Hi Ashish,
my 2 cents. Try corner positioning of the boxes. The polyfill stuffing between whizzer and cone is tunable. I usually do it in layers( concentric ) It has to be relatively tight. The free edge of the whizzer cone should be well damped by the polyfill. Also, try making a small pinhole in the dust cap. (The pole piece resonance will some times lead to shouty midrange.Remember, this dust cap mod is irreversible. If you have a spare driver, try this- Gently remove the dust cap with a sharp knife. Install a phase plug and hear the difference. You will either like or dislike it as per your taste. It will dramatically reduce the midrange shout.

 

[tnvijay]

These Hi Q might perform well in MLTL like WIBAQ, though I don't have personal experience.

 

[aashish351]

This may have more to do with the source, especially if it is from an MP3 player or low-end CDP. Also check your line-level cables (try out a few).

Midrange shout can be tamed by BSC, but at the cost of a few dB in sensitivity. Polyfill is generally a less-intrusive way to reduce it, but it can muffle the lows and lower-mids.

Source is an Audiolab Q-DAC through which only true lossless files are played. Other source is a Technics SL-Q303. The line cables are RCA Ultimate Performance series. I don't think the source is an issue. I will check the line cables but I doubt that will be an issue. On my main speakers - Focal IC-706V mounted in custom designed boxes, the sound with the same sources is very good. In fact, the Focal midrange sounds a bit tamed.

Hi Aashish, Congrats dear, i am also in the same situation as you are in. Did you find any solution of that problem (shoutyness) ? My issue is i have -00 knowledge in DIY speakers and want to create a good pair of speakers for soft music. As of now i have pioneer fs as main speakers bass is super but mid is not satisfactory. Can you or your DIY professional friend help me out in this. Can we meet on this? hyeah:

Thanks accord. Unfortunately, I am still trying to solve the issue as you can see from the messages above and below. More update at the end of this message. My DIY is probably as good as yours. Its not even true DIY!! Design was from a book, wood work by a carpenter, tech support by the amazing forum members here. I am only putting screws and connecting wires and listening! As Kartick also said below, we can definitely meet and crack this together.

Hey Ashish, checked this thread today, so thought should share my experience here. About a couple of years back I had picked up a couple of the same drivers as yours but those were still Philips badged. Those were NOS which I salvaged from a shop that was closing. The guy still charged me a premium labeling those as vintage but the condition those were in, it was hard to pass. Anyway, price is not the point.

Later, I had gotten those measured for their Thiel/Small parameters and went to calculate the cabinet dimensions. Wanted to go the simple route so just went for a sealed enclosure box. The volume required to obtain a relatively flat frequency response for a sealed enclosure was 35 cubic liters. If I was going even to double the volume (45 or 60 cubic liters), it wasn't making any significant changes to the linearity of the FR. So I decided to stick with the minimum stable volume required for the cab, i.e. 35 cubic liters, in the interest of money and real estate that these would occupy.

I will post some pictures later. So coming to sonic characteristics now. Upon using multiple amplifiers (both tube & solid state), my overall impression was that these gave excellent Mids. Though a little crass (what we are calling 'shouty' here). However, considering how much these cost, if paired with a mellow amplifier, these are insane for the vocal reproduction capability. Has a lot of air around the voices and makes it good for watching movies. They lack bass, for obvious reasons. They were not meant to go that low. I feel, these would not be sufficient if one is building a balanced speaker. Can act good for a 2.1 setup or also what I have found workable is that if these can be used in parallel with another speaker which can go low, these accentuate the mids very well. After checking your thread, I tried this parallel configuration and I am very happy. It was just an experiment.

When I was trying to fine tune my setup for my Fostex drivers, which also can feel a little shouty at times. I got a zobel network sort of thing made. It works well for the Fostex drivers. I can try it with the Philips drivers as well. Although, it is not meant for these drivers but I can try, wont do any harm to the drivers.

Once your build is complete, we can also get together sometime and try out these things. Maybe FM Accord might also join us.

Hope this helps.

Thanks a lot for a very very useful account of your experience and understanding of this build. Do you still have the TS parameters for the Philips driver? I know its a different driver, but might be worth a look. My box measures out to be 44.5 liters but its ported. I don't see the port really pushing any air out and when I cover it with my hand, I don't hear much difference. I will try a proper plugging of the port and observe how it sounds sealed.

Interesting idea about trying it in parallel with another speaker. I do feel that my Focals have good bass and highs but a bit recessed mids. So this might actually work. Luckily my Exposure has enough juice even at 4 ohms to take on both speakers.

And, lets definitely get together and do some brainstorming. I will take you and accord on a private message to plan that.

Hi Ashish,
my 2 cents. Try corner positioning of the boxes. The polyfill stuffing between whizzer and cone is tunable. I usually do it in layers( concentric ) It has to be relatively tight. The free edge of the whizzer cone should be well damped by the polyfill. Also, try making a small pinhole in the dust cap. (The pole piece resonance will some times lead to shouty midrange.Remember, this dust cap mod is irreversible. If you have a spare driver, try this- Gently remove the dust cap with a sharp knife. Install a phase plug and hear the difference. You will either like or dislike it as per your taste. It will dramatically reduce the midrange shout.

Thanks Vijay. I will try positioning it in the corner and listen. But almost all speakers I have tried in my room sound better reasonably out in the open.

I can't try the whizzer cone mod anymore! And here is why - when I stuffed it last time, I think the cone movement made the glue of one of the whizzer cones come off and it started making rattling noise. Maybe I stuffed more than I should have. So I tried to peel of the whizzer cone and managed to completely tear it while peeling (and even that didn't stop me and I went ahead to do the same to the other speaker ). So now the speakers are without whizzer cones and dust caps. The interesting thing is - the only change in sonic terms is the slight extension of highs. The midrange character has remained almost the same. I have read this somewhere also that it is a misnomer that whizzer is responsible for any shout. In fact whizzer operates above the frequency range where the shout is most prominent. I will try to find that text again. If I am able to improve the speaker enough to keep it, I will get new drivers to replace these. But for experimentation for now they will work. Luckily there is no damage to the main cone. In fact, Vijay, can you elaborate on the installing a phase plug, maybe i could try that now anyway.

Lastly, yesterday I used the EQ on foobar and played around with the levels to emulate a BSC and was able to reach a setting which seemed to have tamed the shout. And at considerably lower volume than usual for my room, I actually listened and enjoyed music on these for a couple of hours. But, I observed another thing and this probably connects with the advice that this driver might not work with beefy solid state amps. And may work better with tube or low powered amps. The tamed shout through foobar EQ starts to loose the effect as the volume is increased. Maybe because the Exposure can pump more power into these than they can handle. At low volume with EQ, I was able to hear the strengths of these speakers. Maybe this speaker is meant for small rooms and soft decibel levels! The vocal / midrange is indeed very good. And that's why I still want to try and finish this project.

 

[accord]

Hi Kartick & Aashish,

Please intimate me whenever you plan to meet to do some experiments, I have 1pair of box pack HQ48002P drivers lying in my car. These are really good drivers but a bit shouty/ harsh & will work great if that issue resolves and then i will pair them with my Norge 1000 for a dedicated stereo setup.

 

[tnvijay]

Hi Ashish,
The phase plug mod is simple. Fabricate a wooden bullet like thing. At the base, screw a small nail( flat head) and stick it on to the metal pole piece. I did that once based on a internet article. You can find a great resource on modding this one if you search in Google as lencoheaven+ Philips 9710 driver. He gives eloborate ideas and even notch filters.

 

[tnvijay]

Also, this sort of high efficiency fullrangers go very well with low wattage current driven amps ( in contrast to voltage driven) There's a Nelson pass article on this. Suggested amps are my ref,miniref,ampcamp.

 

[tnvijay]

sorry edit: Google as Philips 9710 + troelsgravesen. Four chapters of complete analysis of this speaker is there. I don't know how to link a page,otherwise I would provide a link directly.

 

[kartick]

Interesting article there Vijay. For the time being I have just glanced through it and the following two points struck me immediately :

- This guy's speakers are the Alnico version which may have a better mid range prowess and its shout could be lesser than the ferrite & cheaper version drivers that we have.

- His cabinet volume is 37 liters which is quite close to what I got as per the parameters, i.e. 35 liters.

- Later he moved on to use the Fountek super tweeters which co-incidentally I have also just incorporated in my latest speaker build. I am using the Fountek Neo X2 and it is performing very well.

Regards
Kartick

 

[analogadikt]

its shout could be lesser than the ferrite & cheaper version drivers that we have.

Regards
Kartick

The frequency response peak in the upper mid region is more in case of the 9710. That is why it is 97 Db sensitive compared to the 93 db on the Boston drivers.

Regards,

 

[kartick]

Thanks a lot for a very very useful account of your experience and understanding of this build. Do you still have the TS parameters for the Philips driver? I know its a different driver, but might be worth a look. My box measures out to be 44.5 liters but its ported. I don't see the port really pushing any air out and when I cover it with my hand, I don't hear much difference. I will try a proper plugging of the port and observe how it sounds sealed.

Interesting idea about trying it in parallel with another speaker. I do feel that my Focals have good bass and highs but a bit recessed mids. So this might actually work. Luckily my Exposure has enough juice even at 4 ohms to take on both speakers.

And, lets definitely get together and do some brainstorming. I will take you and accord on a private message to plan that.

Hi Ashish, I would have to check it. Most probably this would be in a friend's computer. Consider that chances are less that I will be able to get it. But whenever I do, I will share it with you.

What I feel is that these do not have that much excursion capabilities so expecting these to move that much air is not going to happen. The magnet itself is also not so heavy. Hence, you might not feel palpable air pumped out of the ports. I believe these were mostly designed to work with the Philips HiQ series of products. Those products were aimed at the Indian market which was playing back the Indian pressed records and were aimed at reproducing vocals well. The music content of that time was also very very different than what is now. Synthesized bass notes were hardly there so if we play that content via these speakers, we may not get satisfied. Best idea is to make these into multi way systems where you play these in their linear frequency range and cut these off appropriately and use a separate subwoofer to play the lows. I am also not a fan of 2.1 systems, that's why I tried this project and then moved on with other stuff rather than introducing a subwoofer. It just doesn't suit my listening ethos. Although just for fun, one time I dug out an active cheap subwoofer that I used to run ages ago (made by Intex) just to see how does it fill up the sound. Obviously the sub reproduced muddy bass notes and it wasnt worth continuing, but what it did was tell me that if you fill up the low notes in conjunction with the philips playing, its not a bad experience. Yesterday I also tried the parallel play thing and it again gave me a pretty satisfying experience.

I have today replaced these philips drivers and have put an old pair of Bolton Acoustics full rangers in the cabinets. The Bolton drivers are far better drivers and have a much more fuller and sweeter sound. These when I play in parallel with my one other pair of speakers, produce very nice results. I tried playing these with a vintage Sansui amp. That amp has excellent reserves of power and drives these two pairs with effortless ease and pushes brilliant bass out. I am so glad I salvaged these Bolton drivers from a junk seller. Although I never got these measured but since the cut out made in the philips cabinet allowed me to put these in, I just did it. I have a feeling these would require a bigger cabinet and would even play better. Maybe Aashish, we can put these in your 45 lit cabinets and see how the results are.

I am sure our meeting to do all these experiments will be an interesting one.

Basically my drive to try these small small projects is just to see how can these not so expensive, yet capable drivers can be put into an implementation which makes people go wow and not believe the actual cost. It has to break the concept that only expensive is good.

 

[accord]

Interesting article there Vijay. For the time being I have just glanced through it and the following two points struck me immediately :

- This guy's speakers are the Alnico version which may have a better mid range prowess and its shout could be lesser than the ferrite & cheaper version drivers that we have.

- His cabinet volume is 37 liters which is quite close to what I got as per the parameters, i.e. 35 liters.

- Later he moved on to use the Fountek super tweeters which co-incidentally I have also just incorporated in my latest speaker build. I am using the Fountek Neo X2 and it is performing very well.

Regards
Kartick

Hi Kartick, can you please share the source and cost of a pair of Fountek super tweeters?

Amit

 

[kartick]

Sure Amit, I bought the tweeters from Madisound. The link is mentioned as below :
https://www.madisoundspeakerstore.c....0-ribbon-tweeter-with round black-faceplate/

There is still a good discount going on these. I'd say if you are really interested in the same, might as well get these. Of whatever I have heard so far, these make music full of life and brings the right amount of air around voices. I am still getting used to the sound however, these have made me hear those passages which were subdued and suppressed with effortless ease and clarity.

I had my relative hand carry this for me. These are fairly heavy when considering a tweeter and you might have to pay significant shipping and duty if getting couriered. Why don't you try ship out of USA website. One of our FMs has tried that option to great avail.

 

[linuxguru]

...Best idea is to make these into multi way systems where you play these in their linear frequency range and cut these off appropriately and use a separate subwoofer to play the lows. I am also not a fan of 2.1 systems, that's why I tried this project and then moved on with other stuff rather than introducing a subwoofer. It just doesn't suit my listening ethos.
...
Basically my drive to try these small small projects is just to see how can these not so expensive, yet capable drivers can be put into an implementation which makes people go wow and not believe the actual cost. It has to break the concept that only expensive is good.

+1. You should consider FAST (fullrange + active subwoofer, most often with an active filter) for each channel if you want to fill in the lows.

If you're not into the active bi-amping thing at all, you should consider the TABAQ or larger relatives like WIBAQ. AFAIK, nobody has tried the Philips/Boston FRs in a quarter-wavelength MLTL yet. Perhaps somebody should experiment with 6" fullranges before going all the way to 8" (mainly a cabinet size/volume issue).

For me, dual 3" or 3.5" fullrangers in a folded TABAQ is close to audio nirvana - I'm not big on deep bass below 55 Hz.

 

[trushar]

I recently undertook full range speaker project using Boston hq 48414p driver
Enclosure volume 40 litres
Reflex port 100mm
Damping material 6mm industrial grade felt, 25 mm glass wool on back wall
Audio Source - Philips DVD Player Lepai LP-2020A
Sound stage very good, some bass not chest thumping,
occasional shoutyness, Good clarity of sound.

 

[kaushik]

View attachment 18461

I recently undertook full range speaker project using Boston hq 48414p driver
Enclosure volume 40 litres
Reflex port 100mm
Damping material 6mm industrial grade felt, 25 mm glass wool on back wall
Audio Source - Philips DVD Player Lepai LP-2020A
Sound stage very good, some bass not chest thumping,
occasional shoutyness, Good clarity of sound.

DVD player is not a source to test these
There are nice FLAC players for 4.5K ...
with some adjustments in a buffer preamp the audio out from these
can make your setup .

Most basic full rangers come with pretty limited support on lower bass frequencies .
Then you will keep looking for a sub build but matching sub is tough task also building
is also effort of many days takin 12-13K of money
That is why the ALPAIR drivers should be a starting point (little premium for the drivers )
but the hard work while creating the boxes is same and final result is guaranteed to be thrilling.
I took part in a DIY made pencil tower and tested with the TRIPATH 20+20
It was very nice.

 

[kartick]

So just to give everyone a crude idea of how the Bolton drivers add life to music (mostly mids and highs), I decided to shoot a mobile phone recorded video in which my latest acquired Sansui AU-X701 is powering the Bolton 8" full rangers in a 35 liters sealed box in parallel with French made Elipson 2145 AM speakers. Pardon the poor quality of the video. The intention is just to demonstrate the effect of the Bolton drivers. Obviously there is no merit it judging the audio quality from a phone recorded video but it does give you some sense. Of course in person the sonic impact is at another level all together.

Viewers note that till around the first one minute of play, only the Elipson are playing. Post that I add the Boltons. Later the Boltons are switched off again and the Elipson alone plays.

Let me know your views. The video can be accessed at : https://youtu.be/3Ex9s_ZsP1k

Try viewing it in 480p or above.