dabman64
Active member
Looking for advice on mods etc. to reduce the bass on my Prodigy speakers. I have installed bass traps and most of the time the bass is just slightly too boomy. Any help appreciated, crossover mods, whatever you might suggest.
Need to reduce the bass output of Prodigy
- Thread starter dabman64
- Start date
Help Support MartinLogan Audio Owners Forum:
You are on the right track thinking that this is likely a room-induced issue, and that room placement and treatments are going to be the best answer.
To help decide what's best, it is ideal to take some measurements. Best would be to do a full REW + calibrated mic measurement, but even some screen caps from the StudioSix Digital Audio Tools app on your smartphone would be good.
Play a pink noise test tone and take several measurements, starting at the MLP, and varying by a foot or two in multiple directions. Log where each sample was measured, and post those here.
Besides room treatments, some EQ will likley be required, but best to know what the baseline is.
What is the associated gear? Do you have a sub as well?
To help decide what's best, it is ideal to take some measurements. Best would be to do a full REW + calibrated mic measurement, but even some screen caps from the StudioSix Digital Audio Tools app on your smartphone would be good.
Play a pink noise test tone and take several measurements, starting at the MLP, and varying by a foot or two in multiple directions. Log where each sample was measured, and post those here.
Besides room treatments, some EQ will likley be required, but best to know what the baseline is.
What is the associated gear? Do you have a sub as well?
Not having any personal experience with the Prodigy model, I looked at the manual and noticed a bass control on the back panel and read about the rear facing bass driver. Without knowing what your setup is - speaker placement in relation to the walls, what the room dimensions are and whether the speakers are against the shorter wall or longer wall, what equipment you have, etc, it's a little difficult to begin a diagnosis.
Adjusting speaker placement without treatments is where I usually begin, along with seating location which hopefully is not backed up against a wall. Suffice it to say, if your speakers are too close to the front wall that can be problematic also. Tilting the Prodigy which changes the rake of the panel can be effective. With your speakers having a rear facing driver you could also try increasing the toe angle greatly and sitting closer which could have a dramatic effect on the bass.
When my audio setup was in a different room arrangement I forced myself to arrange the speakers along the long wall, and then the short wall of a 13'x23' room, I settled on the short wall due to not wanting to sit against a wall. I had bass problems until I brought the speakers 6' away from the front wall and spread them apart forcing a stronger toe-in, and I sat about the same distance away as both speakers were apart. I only found this arrangement by throwing out all information I ever read and spent a couple weeks trying goofy ideas like placing the speakers in the middle of the room, or sit way too close or too far away, trying toe-out and major toe-in, changing tilt, etc. I did all this prior to any room treatment or eq. Once I reached a plateau of diminishing returns, I began treating the room.
If you have a preamp which has parametric eq you can target specific ranges of frequency to adjust.
Adjusting speaker placement without treatments is where I usually begin, along with seating location which hopefully is not backed up against a wall. Suffice it to say, if your speakers are too close to the front wall that can be problematic also. Tilting the Prodigy which changes the rake of the panel can be effective. With your speakers having a rear facing driver you could also try increasing the toe angle greatly and sitting closer which could have a dramatic effect on the bass.
When my audio setup was in a different room arrangement I forced myself to arrange the speakers along the long wall, and then the short wall of a 13'x23' room, I settled on the short wall due to not wanting to sit against a wall. I had bass problems until I brought the speakers 6' away from the front wall and spread them apart forcing a stronger toe-in, and I sat about the same distance away as both speakers were apart. I only found this arrangement by throwing out all information I ever read and spent a couple weeks trying goofy ideas like placing the speakers in the middle of the room, or sit way too close or too far away, trying toe-out and major toe-in, changing tilt, etc. I did all this prior to any room treatment or eq. Once I reached a plateau of diminishing returns, I began treating the room.
If you have a preamp which has parametric eq you can target specific ranges of frequency to adjust.
roberto
Well-known member
Hola,
The Prodigy back woofer should be at leas 3 feet away from its back wall. Also, you might have weak panels...so the bass energy could be more present than the midrange and highs. Just thinking loud. Another possibility is to use bi-amplification, with this set up, you can bring the low frequencies down and avoid the problem.
Happy listening!
The Prodigy back woofer should be at leas 3 feet away from its back wall. Also, you might have weak panels...so the bass energy could be more present than the midrange and highs. Just thinking loud. Another possibility is to use bi-amplification, with this set up, you can bring the low frequencies down and avoid the problem.
Happy listening!
dabman64
Active member
Thanks for the replies, I will fool around a little more with the room placement. The room is 12.5 ' x 18'. One end of the room is partially open and the speaker end is closed. I had a pair of Odysseys in the same spot and they worked out great. I had built some damping panels that worked out well with the Odysseys, but on these I am going to install foam bass traps in the corners to see if it helps. Right now the rear woofers are about 2 feet from the rear wall. I will move them out to 3 feet and see if this helps. Also center of the speakers are about 7 feet apart.
peacefulcargo
Well-known member
One consideration that I found with my Quests was I did not have a powerful enough amplifier dampening the woofers. So went too the Bryston 28SST monos, they completely solved the bass beautifully.
dabman64
Active member
One thing I have noticed with the Prodigy is that the midrange is too recessed for my taste. With the Odyssey's, the voices, piano etc were more up front and life like. I have played around with different driver tubes in my amp and also cables and cannot get the same result that I had with the Odysseys. I purchaed the Prodigys figuring the larger panels would be even more transparent. Getting pretty annoyed with these speakers. In my opinion, if a speaker can't get the midrange right, what good is it? I have 2 more tubes coming that were in my amp originally, and if that doesn't straighten out the midrange, the Prodigy's are history.
On the bass, I did move the speakers out into the room, I measured 3 feet to the rear woofer as suggested by Roberto and that did help a lot. I have several custom wall baffles that I built and I have been moving those around to no avail. I guess it is possible that the room is just too small for the Prodigy's. Setting up the Odysseys wasn't that much of a problem. Equipment is a CJ Premier 140 amp being driven by a PS Audio DirectStream DAC. This combo worked great with the Odyssey's. Can't understand why it isn't working with the Prodigy's.
On the bass, I did move the speakers out into the room, I measured 3 feet to the rear woofer as suggested by Roberto and that did help a lot. I have several custom wall baffles that I built and I have been moving those around to no avail. I guess it is possible that the room is just too small for the Prodigy's. Setting up the Odysseys wasn't that much of a problem. Equipment is a CJ Premier 140 amp being driven by a PS Audio DirectStream DAC. This combo worked great with the Odyssey's. Can't understand why it isn't working with the Prodigy's.
The Odyssey has 8" and 10" woofers with a Minus-3 bass control, the Prodigy has two 10" woofers with a Plus+3 bass control. Seems like more bass is unavoidable, especially when the bass controls work in the opposite way from what you need. I think Roberto has a good idea about biamping for better bass control.
dabman64
Active member
Problem is, I don't use a preamp, so no way to drive another amp. I was considering modifying the crossover, maybe increasing some resistor value. At this point, I am not very happy with the speakers all the way around. I think I am going to give up on these. Maybe look for another pair of Odysseys or even Summits.
I can totally understand your frustration.
Summit is a very good choice. Every chance I got to audition them they always sounded great!
Summit is a very good choice. Every chance I got to audition them they always sounded great!
dabman64
Active member
I discovered that one of the front woofers is bad, voice coil rubbing. I removed the panels for cleaning and was just checking a few things out, and discovered it. Anyone have any idea what a suitable replacement at a reasonable price would be? Thanks in advance.
roberto
Well-known member
Hola,
That´s because the the woofer had lost the coil center due to time. Before you do the change, just put the woofer upside down. The weight of the cone might put it back at the center, and you can have an extra time...try it, it might work. I had that problem, and it is working well.
Happy listening!
That´s because the the woofer had lost the coil center due to time. Before you do the change, just put the woofer upside down. The weight of the cone might put it back at the center, and you can have an extra time...try it, it might work. I had that problem, and it is working well.
Happy listening!
dabman64
Active member
OK, I turned the speaker upside down. I actually had to force the cone down, the coil was rubbing so bad. I will leave it for a day or so just to see what happens. I am looking for someone to repair if first and then look for replacements. Replace one, guess I have to replace both. Nothing special about this woofer, just a plain 10 inch.
roberto
Well-known member
Dabman64,
With much respect, you are wrong. Try to get the same replacement woofer. Why? There is a whole design principle behind the Prodigy woofer, as an example, the frequency resonance of it, the sensitivity and the type of the cone ( aluminum, paper,). Also the circumference of the coil, the depth of it, and the power dissipation rated in watts, has to do too. The shape where the magnet is has to do too. The woofers are set in a special position. This is a patented pending set up by Martin Logan, called Balanced Force. Your Prodigies are a pair of jewels...
Happy listening!
With much respect, you are wrong. Try to get the same replacement woofer. Why? There is a whole design principle behind the Prodigy woofer, as an example, the frequency resonance of it, the sensitivity and the type of the cone ( aluminum, paper,). Also the circumference of the coil, the depth of it, and the power dissipation rated in watts, has to do too. The shape where the magnet is has to do too. The woofers are set in a special position. This is a patented pending set up by Martin Logan, called Balanced Force. Your Prodigies are a pair of jewels...
Happy listening!
dabman64
Active member
Roberto,
I am well aware that the crossover was designed for a specific woofer. Problem is the original front woofer is no longer available. Martin Logan recommends the Scanspeak Classic 25W/8565-00-10 that is available from Madisound. I happened to remember a great speaker repair shop in Pennsylvania from years ago. Company is Miller Sound. I had some speakers refoamed and they did a great job. I sent the woofer to them to repair for a cost of $114 and everything is original as it should be.
I am well aware that the crossover was designed for a specific woofer. Problem is the original front woofer is no longer available. Martin Logan recommends the Scanspeak Classic 25W/8565-00-10 that is available from Madisound. I happened to remember a great speaker repair shop in Pennsylvania from years ago. Company is Miller Sound. I had some speakers refoamed and they did a great job. I sent the woofer to them to repair for a cost of $114 and everything is original as it should be.
roberto
Well-known member
Well done dsvman64!
This way, you are not changing any parameter of the woofer specs. Please understand that I was just warning you about the use of another 10" woofer. There are so many variables that are used when you have a design and quality product as the Prodigies.
If I sound rude or trying to impose myself, it is the barrier language that I have. Please excuse my dare! It is good to know that you are safe now>
Happy listening!
This way, you are not changing any parameter of the woofer specs. Please understand that I was just warning you about the use of another 10" woofer. There are so many variables that are used when you have a design and quality product as the Prodigies.
If I sound rude or trying to impose myself, it is the barrier language that I have. Please excuse my dare! It is good to know that you are safe now>
Happy listening!
dabman64
Active member
Good new, I sent the woofer away and had it repaired. The turnaround time was only 7 working days. While the woofer was out, I washed the panels twice. Installed the woofer and the Prodigy's are performing as they should. Bass is no problem now, as I don't have to crank up the volume on the panels.
roberto
Well-known member
Those are good news!
Happy listening!
Happy listening!
Great news, thanks for the update.
The old woofers flabby or failing suspension must have allowed for over-excursion and been adding substantial distortion (which adds volume). Cleaning the panels I'm sure helps their output as well. Glad the speakers are rebalanced now.
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