The subwoofer enclosure looks a bit like a late addition since it would be odd to have something like that in a paper design since it would have been straightforward to slope or step the top of the subwoofer enclosure. I wonder if the speaker cabinet was originally sized for a ported design?
I think you may need to get them out to determine the component values and the circuit.
Baffle is so thick, it creates a long tube behind each driver - a disaster.
Extensive carving idea anyone?
Last edited:
It is undesirable and needs fixing but I am not sure it is a disaster in the sense of being the dominant cause of problems. Some tests to help quantify the effects.Baffle is so thick, it creates a long tube behind each driver - a disaster.
Extensive carving idea anyone?
Interestingly the same author has developed a crossover for the the OP's metal midrange and ribbon tweeter albeit in a tiny 2 way. Possibly some ideas there. Of course the OP's speaker has a different baffle and the substantially higher SPL requirement means it is hard to believe the combination will be viable but it would be an interesting exercise to find out quantitatively where the limits lie.
Some points to consider:
Is the breakup of the midrange adequately suppressed?
Is the distortion from the tweeter adequately low near the crossover and at high SPL?
Will the ribbon reach its power handling limit at around the same point the other drivers reach theirs?
Is the directivity change smoothly handled?
OP should start simulating a setup with the drivers
he has right now to see if he can come up with an acceptable
solution. The chance to waste more money on some other
drivers will always be there.
I have made a simulation of a 3 way speaker with the same
units (no sub). The fact is there is peaking in woofer response
with series combination being less pronounced. Adding impedance
compensation remedies that to the level of non existent.
Somewhat complicated but feasible.
he has right now to see if he can come up with an acceptable
solution. The chance to waste more money on some other
drivers will always be there.
I have made a simulation of a 3 way speaker with the same
units (no sub). The fact is there is peaking in woofer response
with series combination being less pronounced. Adding impedance
compensation remedies that to the level of non existent.
Somewhat complicated but feasible.
The subwoofer enclosure is about 1'x2'x1.5'. But it is sealed off from the woofer enclosure fairly rigidly.
I am not well versed enough on this to be able to come up with the volume needed to port the woofer, will need some extensive reading.
Could be a possibility, The way it is done now is very shoddy.
Component values werent very clear as i looked for them. But will take the boards out for a closer look as i find time
Last edited:
Thanks Lojzek. How are you running this simulation?
I am aware that some simulation softwares are available there.
I havent tried them yet. As i understand, they have a learning curve and the results need good measurements.
Also, 'fifth element' mentioned that this ribbon tweeter suffers from high distortion at high spl levels and when crossed low.
Others pointed out that the ideal cross over expectation of the midrange and the ribbon drivers makes it a bit difficult to pair them well.
So one suffers from cone breakup if crossed too high and the other offers bad distortion if crossed too low. So the pairing indeed doesnt sound good.
However, Andy pointed out that TG has a small 2-way designed with the exact same pair of drivers.
SPL is not my concern with the mid/high in my speakers. Just that they sound to be too overpowering compared to the 8" woofers and that they simply sound very bad on a fast complex music track
I am a bit confused, please clarify.
OP should start simulating a setup with the drivers
he has right now to see if he can come up with an acceptable
solution. The chance to waste more money on some other
drivers will always be there.
I have made a simulation of a 3 way speaker with the same
units (no sub). The fact is there is peaking in woofer response
with series combination being less pronounced. Adding impedance
compensation remedies that to the level of non existent.
Somewhat complicated but feasible.
Lojzek,
Could you offfer some more details on your simulation. What package are you using?
I am tight on time at this point and cant do justice to learning this, even though i really want to. As i mentioned, i have measurement setup, but from previous experience in room measurements can be garbage unless done right. Again an expertise i lack currently but can acquire through reading and attempts.
btw i failed to mention that i did notice that the two 8" are in series.
Time to summarize again:
Perceived Problems:
1. mid tweeter too prominent
2. Low bass level from 8" woofers
3. Very poor sound quality on fast, complex rock tracks
4. Terrible imaging and sound stage
Observations:
1. Poor quality of baffle construction:
a. no chamfering on mid and woofer mouting holes.
b. small opening for lower 8"woofer and blocking from subwoofer enclosure
2. Tweeter, mid-range pairing questionable
3. Woofer integration with mid/high questionable
Other concerns raised by folks:
1. 12" subwoofer on each speaker is not needed and the 8" woofers can go pretty low if ported:
This one, i am not as concerned. A sealed enclosure design is a fair design target and thats what was pursued for this speaker. Although, I understand subwoofer integration is always tricky.
Solutions suggested:
1. Consider pairing the mid-range with a seas dome tweeter instead.
Cost: Loose exiting mid/high crossover and ribbon tweeter.
Simulate and develop the mid/high pairing and crossover with the dome tweeter. Watch out for mounting of the dome tweeter on existing tweeter mounting hole
2. Fix the mounting holes to the best extent possible. This should help the drivers breath better and reduce coloration due to cavity issues, early reflections etc.
some fine carving with a good chisel, filing, sanding and dremel may help improve the situation. But blockages by tough birch ply enclosure walls is a concern.
3. Throw out existing XOs and go full active. Cost of this tuning , additional amp channels, DSP XO etc sound daunting at this time. Ruling this one out.
4. Try tweaking the exiting mid/high XO and woofer XO for solving the problems.
Without experience, measuring, simulating and tuning sound tough and not sure the end results will justify the time and cost
Perceived Problems:
1. mid tweeter too prominent
2. Low bass level from 8" woofers
3. Very poor sound quality on fast, complex rock tracks
4. Terrible imaging and sound stage
Observations:
1. Poor quality of baffle construction:
a. no chamfering on mid and woofer mouting holes.
b. small opening for lower 8"woofer and blocking from subwoofer enclosure
2. Tweeter, mid-range pairing questionable
3. Woofer integration with mid/high questionable
Other concerns raised by folks:
1. 12" subwoofer on each speaker is not needed and the 8" woofers can go pretty low if ported:
This one, i am not as concerned. A sealed enclosure design is a fair design target and thats what was pursued for this speaker. Although, I understand subwoofer integration is always tricky.
Solutions suggested:
1. Consider pairing the mid-range with a seas dome tweeter instead.
Cost: Loose exiting mid/high crossover and ribbon tweeter.
Simulate and develop the mid/high pairing and crossover with the dome tweeter. Watch out for mounting of the dome tweeter on existing tweeter mounting hole
2. Fix the mounting holes to the best extent possible. This should help the drivers breath better and reduce coloration due to cavity issues, early reflections etc.
some fine carving with a good chisel, filing, sanding and dremel may help improve the situation. But blockages by tough birch ply enclosure walls is a concern.
3. Throw out existing XOs and go full active. Cost of this tuning , additional amp channels, DSP XO etc sound daunting at this time. Ruling this one out.
4. Try tweaking the exiting mid/high XO and woofer XO for solving the problems.
Without experience, measuring, simulating and tuning sound tough and not sure the end results will justify the time and cost
Ok that does make sense, compared to starting from scratch to develop a 3-way crossover for these drivers in this enclosure through measurements, simulations and tweaking.
Let me measure what is going on and then we can see if there are fixes to existing design that can be made for lower cost and time.
I will unmount the crossover boards and try to trace what i can. Though i dont have an LCR, miliohm meter etc to find values if not available.
Folks, thanks for all the help. please be patient with me as i get this data across. These speakers are already a big distraction from very demanding times at my day job and a little kid at home
. Though i love every bit of this audio dope - Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.