| seanzozo |
I built a pair of Ron's Austin 166's and now that I have a few pictures and some measurements I figured I should post.
They sound phenomenal. I previously had these FE-166s in a BK-16, these trounce them in every way.
pics
and
Measurements (done with Room EQ Wizard and a RS meter with a replacement panasonic electret and some modifications):
This is L+R average then 1/3 octave smoothed. The 80-100HZ dip is purely a listening position problem. Listening position is compelled to be in the middle of a ~20*25 room thus the null of the 2nd harmonics 80-100. I don't know about the 700-900 dip...moving the mic lessened it and moved its center slightly but never fully removed it.
Note the 43hz extension. The RCH which is loaded into a corner gets smoothly to 40 and then rolls of smoothly. The LCH loads into a hallway and drops off quickly after 45 hz.
I'm impressed...the extension of a MLTL without BSC and with all the dynamics of a BLH. I havent yet built the triangle reflectors...currently using a footlocker as a substitute in the RCH.
Sean |
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| gychang |
| quote: | [i]
pics
and
Sean [/B] |
Sean, let me be the first one to say "wow".
Where did u get the plan?, would like to follow the thread and maybe more pics if u modify more... |
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| seanzozo |
Thanks for the compliment.
The design is the Austin Rev G designed by Ron (who also designed the A126 and the Dallas). It can be found at:
www.FullRangeDriver.com
There are a few threads on it.
The plans are in the gallery there under "Austin Rev G BLH for Fostex FE166E driver". Ron suggests a few alteration's from the plan. One is the trapezoidal baffle that you see (though it should have 2inch extensions trailing backward that I haven't doen yet), its taken from the Austin II (you might find the plans under layertone austin on the fullrangedriver forum- not the gallery). The other is detaching the rear triangular prism deflectors, which I have yet to build.
Sean |
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| bigbrowncow |
I've also built a pair of these - without the extended baffle and with just one bass reflector for now.
They sound delicious and the bass is definitely there.
Next job is to build the second bass reflector and put both speakers on marble slabs - I have partition floors and the speakers are still shaking the floor by the listening seat...
How are you going to finish them? I used shellac which was far too much work...
Steve |
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| seanzozo |
I think I remember seeing pics of yours up on fullrangedriver a while back. I used shellac on my previous cabs, these have much more surface area and I think I'll do a simple wipe-on poly.
I have been having vibration issues with everything on the back wall, and my turntable on the sidewall. Now I need to build a decent turntable base :).
Sean |
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| ronc |
Glad yall like the design.
ron |
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| edjosh23 |
Ron,
Glad to see you joined diyaudio.
Josh |
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| ronc |
Glad ta be here. I had real problems with my last puter and linking to this forum. But the last puter died of virus content.
The new puter has no problems. Only problem is i lost the majority of my CAD files, so i have been attempting to re-create the designs. I did not lose the acoustic programs however.
On the A166, i would recommend the supra baffle (name coined by Dave) and the deflectors to achieve proper performance.
ron |
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| seanzozo |
I had some friends over tonight and listened to Calexico's "Things fall apart." I never did enjoy the last track until I got the extension that these provide.
Ron, I was wondering according to your model what should be the max SPL at x-max in the 40hz area with corner loading? I have been shocked by the cone control and concomitant bass SPL that these are capable of.
Sean |
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| layertone |
> I have been shocked by the cone control and concomitant bass SPL that these are capable of.
I'm still shocked by Ron's Austin IIs!!! The cone barely moves and the lows are very present - very perplexing because the cone movement doesn't really match the big output! Absolutely addicting & mind-boggling!
Working on a "layertone" version of the Frugel, really want to build another Austin II; think this time it'll be painted
Thank you Ron (repeating myself again)!
Tony |
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| bigbrowncow |
It's great to see you here Ron.
I wish you luck with rebuilding the cad files. It sounds like a lot of work, so I hope it all comes back without too much trouble.
The Austins really do sound great. I think my biggest problem making the bigger baffles is going to be living without them for a few days while I route out the existing baffles and redo the wiring. Not sure how I'm going to manage with the silence.:whazzat:
Steve |
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| ronc |
| quote: | | Ron, I was wondering according to your model what should be the max SPL at x-max in the 40hz area with corner loading? I have been shocked by the cone control and concomitant bass SPL that these are capable |
Well, lets put it this way. Using wall floor loading and the deflectors the Xmax limit should peak at the average FR for that SPL in the upper frequencies.
If the drivers are rated at 94 db/watt/meter then the xmax limit will be reached at that point when wall/floor loaded. However greater loading via the corner will change that and i never ran sims for that condition. I never really sim for corner loading as that is a variable of the room dimensions.
The FR curve that zozo ran is very close to my calculations when both horns are wall/floor loaded.
ron |
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| ronc |
| quote: | | I'm still shocked by Ron's Austin IIs!!! The cone barely moves and the lows are very present - very perplexing because the cone movement doesn't really match the big output! Absolutely addicting & mind-boggling! |
Welcome to the world of properly designed back loaded horns.
ron |
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| preiter |
I did some searches on the full range driver forum and all the links I found seem to be broken.
Where are there up to date plans for these speakers? |
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| seanzozo |
Here are Ron's plans:
http://fullrangedriver.com/gallery/...044/Austin1.pdf
http://fullrangedriver.com/gallery/...044/Austin2.pdf
http://fullrangedriver.com/gallery/...044/Austin3.pdf
http://fullrangedriver.com/gallery/...044/Austin4.pdf
Notes:
1) The baffle is not present in these PDFs. It sould be 12.7 inches square, ~2.1 inches thick (3 layers of 3/4 ~ 2.1 inches) with a 45 degree bevel and a 2 inch extension around the perimiter facing rearward. (Added benefit, the remainders from the baffle beveling can be trimmed to make the 45 degree cleats in the first bend of the horn)
2) The second bend in Austin1.pdf has an error it should according to Ron:
"I looked at the orig dwgs. Start of second 180 deg bend is 4.05" middle is 4.46" end is 4.72". This is the calculated expansion for that distance.There should be no "hump"."
3) It is convenient IMHO to construct the speaker and the deflector as two seperate peices. This adds one issue, the speaker becomes slightly front heavy with the driver and baffle sticking proud of it, I added a few inches of base sticking out to the front (with a slight .25 inch bevel to match the general look).
4) Getting the peices of the horn as accurate as ron plans is difficult. I had no difficulty with getting the side I drew the plan on matched up but getting absolutely perfect 90s is hard on some of the interior peices. An error of 1 degree is .13 inches. I would recommend cutting spacers of the exact width of the gap from the leftovers of the stuff cut to 7.9inch width (cut this all at once!!!) at different places (i.e. the throat and the bends) and clamping them in there while gluing to be certain of the geometry.
Sean |
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| ronc |
Sean, i have been developingmy baffle programming and i noticed that there is a high degree of probability that the 900 Hz dip could be caused by forward edge diffraction. If the trailing edges are installed this could eliminate the dip.
I am seeing some interesting things in the above programming. Even OBs have a very apparent edge diffraction. If you look at an OB as a horn with zero length and no acoustic gain then the end result is very near the same. What i mean to say (and doing a poor job at it) is on the positive wave launch(displacement is positive on the front of an OB and negative on the rear) the positive wave has more energy at the edges than the negative wave, then the action reverses as the cone moves180 degrees according to the sine point. This is a dual type edge diffraction as on sims that i have made a negative wave has the greater energy(partical mass concentration) in the center and falls off faster as the angle increases from the centerline than a positive wave launch of a transducer ( the OB being considered as a secondary transducer).. I believe i wrote a short artical about this observation in the FR articles forum.
I dont know if i am making myself clear on this action? Simply stated , an OB has more constant energy arriving at the edges than a normal box enclosure due to the fact that the dipole action is being produced on the same plane.
Conclusion: If an OB has a greater edge diffraction possibility then rounding of the edges will have a positive impact on the end result. A 3" OD piece of PVC with a slot cut down the length , to fit to the thickness of the OB panel ,would be a good place to start.
ron |
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| MJK |
| quote: | | What i mean to say (and doing a poor job at it) is on the positive wave launch(displacement is positive on the front of an OB and negative on the rear) the positive wave has more energy at the edges than the negative wave, then the action reverses as the cone moves180 degrees according to the sine point. This is a dual type edge diffraction as on sims that i have made a negative wave has the greater energy(partical mass concentration) in the center and falls off faster as the angle increases from the centerline than a positive wave launch of a transducer ( the OB being considered as a secondary transducer). |
Ron,
Are you saying that a source oscillating with a symmetric sine wave type of displacement, will produce a pressure at the baffle edges that deviates significantly from a sinusoid due to unequal "wave launch"? The compressive half of the cycle behaves differently compared to the rarefication (spelling?) half of the cycle as seen from some listening position away from the source be it the baffle or the driver? If you are indeed saying this then I am having a hard time with the concept. I would have to believe that if this is a significant nonlinear contribution to the sound that the distortion produced by this nonsinusiodal action would overwhelm any good musical reproduction obtained by linear theory. How big are the deflections, pressures, or velocities that you are simulating? Are they consistent with typical listening SPLs? |
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| ronc |
Well Martin my simulation software i have been developing is based on hydrodynamec principals with an adjustment for the mass/desnity of air density at sea level.
The effect is a more vortex action whan the cone moves inwards, When there is a positive displacement the full effect of the baffle is affected..
| quote: | | Are you saying that a source oscillating with a symmetric sine wave type of displacement, will produce a pressure at the baffle edges that deviates significantly from a sinusoid due to unequal "wave launch"? The compressive half of the cycle behaves differently compared to the rarefication (spelling?) half of the cycle as seen from some listening position away from the source be it the baffle or the driver? If you are indeed saying this then I am having a hard time with the concept. I would have to believe that if this is a significant nonlinear contribution to the sound that the distortion produced by this nonsinusiodal action would overwhelm any good musical reproduction obtained by linear theory. How big are the deflections, pressures, or velocities that you are simulating? Are they consistent with typical listening SPLs? |
What i am stating is there is a greater pressure near the edge of a baffle when there is a positive pressure applied. This pressure becomes an edge diffraction issue as the edge appears to become a secondary transducer with less energy.
I keep seeing the negative ( cone moving inward) as a centered spiral towards the center with less energy at the edge of the baffle. Whether it would deviate in a significant manner or amount will require more study, however, its there.
I keep seeing the same result, as the cone moves inward on a plane the action resembles the flushing of a toilet ( crappy analogy) as a vortex is formed which means more energy in centered around the piston and less energy on the plane surface away from the centerline of the transducer than a positive stroke.
How big are the deflectors, will i sim from 32" to 10" and the results are the same ( disregarding attenuation).
Any wave travelling over a surface that ends upon an edge will produce a secondary action that i consider as a secondary transducer. This secondary transducer will produce a later timed and less energy production than the primary.
An OB can be considered as a secondary transducer with the effective area being a launch platform for a given frequency.. As i have stated there is a differential in pressure at the edges at different sine points so therefore on a dipole action with the same given plane there has to be a greater total edge diffraction result than a singular plane action.
In hydrodynamics if a piston moves inward there is a vortex formed, if the piston moves out then the energy is spread over a greater area.
ron |
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| MJK |
Ron,
I understand the secondary source analogy at the edges of an OB or the edges of an enclosure, I have progammed this in my MathCad worksheets for both OB and any of the box rectangular geometries I have made available. What I cannot understand is how positive and negative displacements of the driver could produce anything but equal and opposite responses at the edges, which is what I think you are implying. If we are talking small deflections in air, I have to fall back on the response at the edges (or anywhere between the source and the edges or beyond the edges) being equal but opposite for a driver moving forward out of the baffle compared to backward into the baffle. This is what the science of acoustics is based on and every textbook I have on my shelf uses this feature as a fundamental building block for deriving all of the relationships presented starting in the first chapter. If I undertand what you are saying your model produces results that are nonlinear, do not satisfy or allow superposition, do not fit into the Fourier theory of series expansion or transforms, and are not governed by any of the wave equations (small oscillating motion of air) I have ever seen derived. Do I understand what you are saying correctly and is that what you believe is really happening? I would be extremely surprised if "hydrodynamic principals" did not reduce to the basic wave equation if the correct simplifying relationships were used to remove non applicable terms in the equations.
If I have paraphrased you correctly, and I step back from the very complicated math you are obviously doing, does this make physical sense on a very fundamental level? I have to admit I have my doubts, not that my opinion really matters. Can your method reproduce curves of baffle defraction response similar to the classic (measured I think) curves in Olsen's acosutics text as a sanity check? My MathCad worksheets can with what sounds like much easier math. |
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| ronc |
On perfection
There is none, i was just in Audio Asylum and there was an answer to one my quotes from here that i had to be wrong as Nakoda(sp) could not be wrong.
This is one sided thinking, and shows no expansion of thought, In any endevor there is an advancement of information and technology application. If there wasent we would still be driving cars with carbs and not computer controlled fuel injection and exactly timed spark.
The principals that were laid down by the greybeards are subject to change as technology advances greater defination occurs, nothing is ever written in stone and even physical principals (or the reasoning behind them) can change.
Every aspect of any field of physics changes to adapt to new learning and greater analytical power. If it didnt we would still be thinking that if you sailed too far on an ocean you would fall off an edge.
I have no doubt that when i publish my final findings that some smart young dude will come up with the proof that i was full of it and prove me wrong. I would be dissapointed if this didnt occur.
Its called "progress".
I will get into this in greater detail when i have the opportunity.
thanks
ron |
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| ronc |
| quote: | | I would be extremely surprised if "hydrodynamic principals" did not reduce to the basic wave equation if the correct simplifying relationships were used to remove non applicable terms in the equations. |
That has happened to me many times.
| quote: | | Can your method reproduce curves of baffle defraction response similar to the classic (measured I think) curves in Olsen's acosutics text as a sanity check? My MathCad worksheets can with what sounds like much easier math |
That is my goal. I just happened upon the wave form difference while trying some sims. I wil study the coding to assure i havent made an error and to refine the values.
In the sims i see the same effective pressure on positive and negative strokes, its just that the negative stroke partical mass shifts towards the center. I will refine and report back as something like this is interesting to me.
ron |
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| MJK |
Ron,
| quote: | | The principals that were laid down by the greybeards are subject to change as technology advances greater defination occurs, nothing is ever written in stone and even physical principals (or the reasoning behind them) can change. |
Agreed. However when I find myself at odds with the greybeards, I am always wrong. I would be very nervous if I found I was in conflict with mathematics/physics that is several hundred years old and still standing as being correct.
| quote: | | This is one sided thinking, and shows no expansion of thought, In any endevor there is an advancement of information and technology application. If there wasent we would still be driving cars with carbs and not computer controlled fuel injection and exactly timed spark. |
I worked with a guy a long time ago, very bright with a Phd and many years of experience. One time he got his nose so close to his calculations he was blinded by his own derivations. He proved that the sine of an angle could be greater than 1.0 and would argue the point because he needed it to make his equations match reality from a test result. I remember my grey headed boss tossing him out of his office based on that one sticking point.
One sided thinking is definitely the enemy of progress, but so is violating basic physics and math. Just because a computer program produces a number it is not necessarily 100% correct. If your computer methods cannot reproduce simple classic solutions I would be suspicious of the more complex results, that comes form somebody who has screwed up and been fooled many many times. |
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| ronc |
have been shocked by the cone control and concomitant bass SPL that these are capable of.
I have been thinking on this factor. The normal " hit or miss" designs in the past have very little( or generalized) acoustical physics application. I have even seen statements like " a CC volume between 3.5 to 5 liters". To me, as an engineer, this is like saying that any huge tolerence in any system is acceptable. The only reason for a tolerence in any design is to adapt to manfacturing and required performance potential. Its normal to say that a tighter tolerence cost more in the end product, but as you approach a tighter tolerence you achieve a closer to optitum performance potential. Its very simular to " blueprinting" an engine in which you take the engineers nominal requirements and re-define the tolerences to a tighter margine to achieve a greater performance.
In horn systems this means defining exact values and combining the target goals to achieve the maxium performance from the most simple design with the less(or none) wasted space.
One of the great falsehoods i have seen is an equal loading requirement from the front surface of the cone to the rear, the loading affects both surfaces regardless if its one one side or the other. Its nothing more than a piston with loading.
ron
ron |
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| MJK |
Ron,
There are obviously some tolerances that are extremely important in a design and are highly optimized. Then there are tolerances that are really not so critical, typically this is the majority. If you over tolerance a part you drive the cost out of sight for little gain. I worked with a some engineers that put tight tolerances on every feature of their part because they could not visualize what was important and ended up with something so expensive it was not competitive. But lets return to horns ...
| quote: | | I have even seen statements like " a CC volume between 3.5 to 5 liters". To me, as an engineer, this is like saying that any huge tolerence in any system is acceptable. |
I am not so sure. Remember that most of the hit or miss full range BLH designs are paired with low power tube amps. The output impedance of the tube amps is all over the map. So the effective Qts of the driver probably has a significant tolerance leading to a large variability in the required CC volume. The only way I see of tightening the tolerance on the CC is to design for SS amps. But that would be a non-purist approach and looked down on by the enlightened.
| quote: | | In horn systems this means defining exact values and combining the target goals to achieve the maxium performance from the most simple design with the less(or none) wasted space. |
Only if you include a specific tube amp and only one driver in the optimization. If not then you need some adjustability in the enclosure design.
| quote: | | One of the great falsehoods i have seen is an equal loading requirement from the front surface of the cone to the rear, the loading affects both surfaces regardless if its one one side or the other. Its nothing more than a piston with loading. |
Ageed! There is a lot of bad information voodoo floating around with respect to full range drivers and horns that is being quoted as absolute truths.
One of the most entertaining threads I have read recently is over at the OB forum of the Audio Circles sight. A great discovery has been made by the single driver OB users. You can use a BSC circuit to rebalance the rising SPL response and it improves the system response dramatically. The life is not sucked out of the music and it really sounds better with the circuit! Every day I check the progress of this advance in the full range driver technology, sooner or later they will figure out it also helps the boxed speakers. |
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| ronc |
| quote: | There are obviously some tolerances that are extremely important in a design and are highly optimized. Then there are tolerances that are really not so critical, typically this is the majority. If you over tolerance a part you drive the cost out of sight for little gain. I worked with a some engineers that put tight tolerances on every feature of their part because they could not visualize what was important and ended up with something so expensive it was not competitive. But lets return to horns ...
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So true. I have learned , the hard way, to establish tolerences toward what the final goal is. If you are trying to establish a " form fit and function" requirement then its different. I keep seeing ppl who ask will this different driver work in a design and i can only state, not to the optitum. I spent the majority of my life in aerospace, it was always better to be too tight than too loose.(CYA action). Lordy! most of my work would be blown up upon impact or detonation, so goes the hidden mistakes.
| quote: | am not so sure. Remember that most of the hit or miss full range BLH designs are paired with low power tube amps. The output impedance of the tube amps is all over the map. So the effective Qts of the driver probably has a significant tolerance leading to a large variability in the required CC volume. The only way I see of tightening the tolerance on the CC is to design for SS amps. But that would be a non-purist approach and looked down on by the enlightened.
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I try to design for the " middle of the road" approach. True its not optium, but its the only approach i can take for the masses. Most dont understand that the amp is part of the system, or the room volume or shape or even the source. To truly design for a given set of conditions would require several designs that i truly dont have time in my life for.( just discovered fly fishing for stream trout in NC with my lady, a hell of a lot more enjoyable than designing automated inspection systems for industry)
| quote: | | One of the most entertaining threads I have read recently is over at the OB forum of the Audio Circles sight. A great discovery has been made by the single driver OB users. You can use a BSC circuit to rebalance the rising SPL response and it improves the system response dramatically. The life is not sucked out of the music and it really sounds better with the circuit! Every day I check the progress of this advance in the full range driver technology, sooner or later they will figure out it also helps the boxed speakers. |
A great discovery LOL. Most do not consider the benefits of electronic compensation. They are hung up on some passive EQ system that they had in their dorm room. I primarly design around the horn/TL system due to the increased dynamic range and greater efficency, however most are not willing to invest of themselves into the greater design complexity.
ron |
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| ronc |
The only way I see of tightening the tolerance on the CC is to design for SS amps. But that would be a non-purist approach and looked down on by the enlightened
Then i guess i am one of the unenlightened.
ron |
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| Scottmoose |
Martin, Ron, is that a private club or can anyone join?
I leave the purist brigade, who frown upon anything that is actually designed rather than glued together with snake oil, to get on with it as well. |
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| ronc |
Well as far as amps go, i have everything from SET to Phase Linear ( you could weld with that one) and just about everything in between.
My current fav is battery powered Gainclones , but that is just a phase. One of my all time fav is some of the older Marantz 22xx( pre 1980) that i enjoyed rebuilding and slightly hopping up. Those amps gave a tube like sound with power to spare and one of my restored 2238 amps is driving my first horn design at my parents house. It still sounds good with the fostex Fe103 in a short horn with rapid expansion but Dad with his hearing loss ( God bless him) still complains that Benny Goodman just dosent have the punch that he heard live ( what ya expect?).
I am truly a fan of SS amps as they have the power and the inherent damping that even with HE horn systems make an obvious difference. Problem is most of todays SS amps are way overrated in watts and do not perform like the older equipment when power ratings were measured differently. Moms and Dads Marantz 2238 weighs about 40 lbs , with the original wood cover. It is only rated at 38 watts/channel. I have seen newer amps that were rated at 200 watts/channel that weighed around 10 lbs. I even tried explaining to a sales person that the advertised watt out put was more than the consumed power, after looking at the fuse rating and allowing for a 100% efficency conversion.
So much for new. There are still good newer amps out there , but you have to spend the $ to get IMHO what is considered acceptable performance.
ron |
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| dimitri |
Sean, can you contact me?
Thank you, |
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| bigbrowncow |
After 9 months I have just:
- finished off proper gravel filled deflectors
- put a bit of acoustic foam and felt inside the CC rather than old ceiling tile
- added a pair of phase plugs
- blutacked the speakers to some concrete slabs
Each one of these mods made a profound difference. Phase plugs especially seem to have opened up the treble in a very special way.
Yay! :D
Still no suprabaffles though - "I'm not having speakers with earlobes in our lounge" etc.
Steve
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Gwen Nathan Photography
www.gwennathan.co.uk |
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| planet10 |
:)
Are you in any of your wife's photos.
dave |
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| bigbrowncow |
| quote: | Originally posted by planet10
:)
Are you in any of your wife's photos.
dave |
Here's one just for you!
Steve |
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| planet10 |
:)
i like the shirt... |
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