Xerxes75,
Hi, again.
Please, for the forum doubts, mention the type of amp you are using and the max. power (RMS/approximate) you r using, if you can, for info/understanding of the various options and project types. I understand you are using the 12202-M8 in a 104 L/BR, right?! With the larger 110 tube, how much was the length again?
Hi, again.
Please, for the forum doubts, mention the type of amp you are using and the max. power (RMS/approximate) you r using, if you can, for info/understanding of the various options and project types. I understand you are using the 12202-M8 in a 104 L/BR, right?! With the larger 110 tube, how much was the length again?
I make the aluminium ring myself I use a simple (wood)router and the lowest speed and WD40 and some patience. The technique is the same as a wooden circle.
I must admit dat I am not formiliar with an Aperiodic port. Those vintage are rare but in the Netherlands you can still find them. Strange thing is that on this moment there are quite a few available.
The amp I am using is the First One Module from Lazy Cat 230Watts into 4 Ohm. And yes I am using the 110mm tube with a length of 15.5cm and 1cm flare on the outside end.
As mentioned I loved my old drivers (in their Open Baffle setup). But that was to dusty and had an impossible small sweetspot also I wanted t build something. During that proces I killed my old units and bought other ones. They sound still great but very different. In this cabinet however the sound is bad. I learnt from someone who has ten pair of these that the all sound different.
I tried the tweeter but then it gets even more harsh.
To give you an idea of the sound...the sound high very high, a bit hollow and chilly/harsh . The whole midrange seems to be lost. When driven a bit louder there is Bass and lost of it! The sound does not comes loose from the speakers, worse is seems to be on the backside of the speaker.
Another problem is that the sweetspot is even smaller if you can find it and due to the height of the cabinet the sound stays low to the ground.
I due think that the damping could be a problem, earlier I mentioned my doubts about damping.
Off course I wished that I never took this turn and kept my open baffles but that is a bit to late...
To give an idea on using a router on aluminium I attached a picture of the bottom of my amplifier
Attachments
I think the AD1202M is fairly similar to the AD5200 wich I owned 4 pairs of. It is quite common for the voicecoil vire to brake since they are old and quite delicate. If you loosen the screws on the backside of the magnets and carefully lift it of the basket and voice coil you should be able to see were the voice coil wire broke. If it is where the wire meets the cone just unwind one turn or as many turns of the voice coil as needed to be able to reconnect it to the cone again and "voila" it should be playing again. Don't know how this effects the parrameters of the drivers but at least you should be able to make it sing again. I had this problem with one pair of my AD5200 and they play wonderfully again after this fix. Must admitt that I got help doing this, but it is doable at least.
If you have two pairs maybe you could try to mount one of the driver pairs over each of the boxed drivers simmilar to TEKTON OB4.5 and linkwitz lx mini but filterless. That is atleast something I want to try.
Just saw a picture of the backside of AD1202m8 and the magnet does not have the three bolts that you can loosen and pull of the magnet as on the AD5200 I have. Maybe someone else knows how to get the magnets of?
To the OP,
Can you describe better what is the problem with the sound?! (What frequencies and strengths/hot sound or other.)
I find that you have a (data from database of Philips AD12202M8, I can test with data from this thread in a second test/simulation) 104 L/BR@34Hz alignment, a little to squeezed for the driver to come alive (in bigger cabinet). Port 11cm/15.5cm. Port resonance 1115 Hz.
LF extension F6=38.5 Hz
Note: You need protection for the driver at LF under 25Hz (30Hz?) if using max power. Picture below for 28V (~100W, 7.8 Ohms@34.0 Hz). This can be one reason for problems.
Can you describe better what is the problem with the sound?! (What frequencies and strengths/hot sound or other.)
I find that you have a (data from database of Philips AD12202M8, I can test with data from this thread in a second test/simulation) 104 L/BR@34Hz alignment, a little to squeezed for the driver to come alive (in bigger cabinet). Port 11cm/15.5cm. Port resonance 1115 Hz.
LF extension F6=38.5 Hz
Note: You need protection for the driver at LF under 25Hz (30Hz?) if using max power. Picture below for 28V (~100W, 7.8 Ohms@34.0 Hz). This can be one reason for problems.
Attachments
Pepe.. I would not place the AD5200 and the AD 12202 in the same category I have own several. And yes the magnet hasn't got bolts it is glued on...unfortunately.
Inductor... I can't measure anything so no more data. I find my self in your remark off more breathing room.. The only thing more I can say about the sound is that it seems to be all there but it is "inside" the box..
The measument on the data sheet are taken with the driver in a 90litre closed box..
Well maybe I just got it wrong and have put looks before data but it would be nice to get it Running..
(As side project...)
As I was looking at other drivers for this enclosure I saw the Eminence Beta LTA.. Would that be worth trying or does this also benefits more from an open baffle?
R.
Inductor... I can't measure anything so no more data. I find my self in your remark off more breathing room.. The only thing more I can say about the sound is that it seems to be all there but it is "inside" the box..
The measument on the data sheet are taken with the driver in a 90litre closed box..
Well maybe I just got it wrong and have put looks before data but it would be nice to get it Running..
(As side project...)
As I was looking at other drivers for this enclosure I saw the Eminence Beta LTA.. Would that be worth trying or does this also benefits more from an open baffle?
R.
Are you saying you prefer the ad12202m8 over ad5200? If so I will grab a pair on the 2nd hand market. I know alot of guitar players who prefer the ad5200. But then again guitar player look for other things then we do in home audio.
The AD5200 are great speakers don't get me wrong buit the successors AD12100 and AD12202 are more of this time? more complete? I can't get the right term. Let put it the other way around, I would not use the AD12202 in a guitar cab and would use the AD5200 instead.
Unfortunately I went for the looks while waiting for my second pair af driver and glued them in place. Of course I prefer not to mess with them but if the answer lies there I will break them out.
I have difficulties reading numbers and read long text which use enormous amounts of specs and number etc. and so I rely on what others write. I did not try other settings to the length of the pipe. Until now this always went very well...it had to wrong at some point..
To answer your question on LF HF etc.
HF are dominant
Voices are dominant
LF are only convincing at loud volume
Mids seem to lack
Percussion is more tapping on a peace of wood, and sharp
When I sit a bit further away at the dinning table HF are even more dominant.
When play loud(ish) Hf are irritating LF are prominent and (to) convincing but the Mids(?) still seem to lack..
Maybe it is logical since I put the drivers in box instead of an open baffle but I do need to crank up the volume more than I had imagined.
I know there are many variables and having to replace the drivers midway of the project does not help..
R.
Very diplomatic. Will keep my eyes open for a pair of the newer philips 12" with whizzer.
By the way I like the looks of your br cabs. Simplicity is appealing, less is more!
Conjugate network for attenuation in HF from 500Hz and up...
To attenuate the loudspeaker in HF only, +/-6 or 7dBs, use 1.5mH inductor and 15 Ohms resistor network.
To attenuate the loudspeaker in HF only a little use less (i.e. +/-4dBs use 0.82mH inductor and 6.8 Ohms resistor network.)
Use low DCR inductors.
Test.
To attenuate the loudspeaker in HF only, +/-6 or 7dBs, use 1.5mH inductor and 15 Ohms resistor network.
To attenuate the loudspeaker in HF only a little use less (i.e. +/-4dBs use 0.82mH inductor and 6.8 Ohms resistor network.)
Use low DCR inductors.
Test.
Attachments
Let's see the other way around;
If you attenuate the HF the mids that you say is lacking will come to life. So will the LF, a little, as you will level or attenuate the mids and high frequencies even more, LF will become a little stronger. That's acoustics nature I guess. Have fun.
Hi. Well I have learned a new thing... Somewhere in my mind I thought that attenuate was the opposite of what you say...so in my mind your solution would mean to lift the HF up!
Unfortunately I can't go to the local store to pick up the parts needed. Yesterday on my way to the supermarket I tript and took a dive into the pavement. The result is some ripped muscles in my torso and a broken rib.
Never knew that shopping could be dangerous...
R.
Unfortunately I can't go to the local store to pick up the parts needed. Yesterday on my way to the supermarket I tript and took a dive into the pavement. The result is some ripped muscles in my torso and a broken rib.
Never knew that shopping could be dangerous...
R.
Bummer! Hope you heal good and quick.
FWIW, the USA's insurance cartel once claimed that nearly 100% of all accidents were within 4 mi of home and that nearly 99% of all injuries were at home/property, so if you're anything like me, need to pay more attention when doing even the most mundane/automatic of chores rather than 'daydreaming'/whatever, especially as we get older as me and some of my friends/neighbors have learned the hard, painful way. I've known folks who have either died, or wished they had, from lesser injuries.
GM