[jeffb335]

Yes, I was skeptical when I saw the surrounds on the speakers, not alot of xmax potential there, but they play down low just fine. Max output probably isnt all that high, but its higher than Im ever going to need in regular use.

[nato-main-man-5am]

Originally Posted by jeffb335

Success with the Jehnerts!

Ordered a set from MusicarNW a couple weeks ago, my hope was to be able to get rid of my trunk sub for utility reasons. I was hoping to get "good enough" bass from the underseats for regular listening.

Install was a breeze, I was done in less than an hour. Got the MS8 fired up, did some calibration and it seemed that "good enough" wasnt going to happen, just not enough output. So plan B took over and I left the trunk sub in and calibrated some more, fiddled around and ultimately was 100% happy with the sound quality. The midbass was as close to perfect as I have heard. Solid but open, up on the dash, sweeeeeeeet!

So yesterday I got to thinking....I wonder if I went "old school" and ignored what the MS-8 wanted to do and just adjusted the underseat woofers by ear on my amp and EQ, could I get them "good enough" to leave the trunk sub out most of the time and not really miss it?

Turns out the answer is YES....

I ended up bumping up the gain a bit on the amp and doing about a 3db rise down to about 50hz on the 32 band EQ. And it sounded pretty damn good! Almost equivalent to my trunk sub when I had it set to a normal comfortable level. And the Jehnerts didnt seem to have any problem with it, still great SQ, just playing lower.

And as proof to myself that it was going to work I left all the settings overnight, got in the car this morning, put on some music, and my first thought was "I need to turn the woofers DOWN a tiny bit".

I left my sub amp and a speaker plug in the car so I can throw my sub back in the car if I want to show it off, I set up a different "favorite" on the MS-8 with the optimum settings for running the sub so its easy for me to switch back and forth. So going from optimal settings with sub to optimal settings with underseats as subs is just one switch on my amp (hp xover) and one setting on the MS-8.

Certainly if you are a bass head this is not for you, but for regular listening and preserving trunk utility it seems they fit the bill.

That sounds very promising. What kind of amp are you using for the Jehnerts?

[jeffb335]

Arc mini

[nato-main-man-5am]

Cool, just for the underseat woofers?

I guess the bass boost in the amp is useful too for getting the most from the Jehnerts? ("BX2 is a bass frequency extension technology that provides perceived bass frequency response below the low frequency cut off in an audio system.")

[jeffb335]

Yes, arc mini on the jehnerts, ms-8 on everything else.

Then I have a sub and sub amp as well but that is what I was trying to get rid of.

[VP Electricity]

Originally Posted by Nathan_h

Cool, just for the underseat woofers?

I guess the bass boost in the amp is useful too for getting the most from the Jehnerts? ("BX2 is a bass frequency extension technology that provides perceived bass frequency response below the low frequency cut off in an audio system.")

We do not use that feature and tell everyone to leave it off. I would especially not use it with an MS-8 (at least not during calibration!)

It's not really a bass-boost anyway, it's the MaxxBass "missing fundamental" chip - google "missing fundamental" - and while I know that some folks have liked it, it's never seemed to make a difference in my testing. I was really excited back when the MaxxBass feature came out 5 or 6 years ago - from what I was told, it was going to let us delete trunk subs for a lot of listeners - and then was way underwhelmed.

I run the 125.4 in my car, which does not have that feature, and the Jehnerts did fine without it.

[jeffb335]

Hi Ken.....I was about to ask you about this....

I had tried the Arc Mini's BX2 feature a few days ago when I was experimenting but assumed at the time that it was just a bass boost (thats what it sounded like) so when I heard the over accentuated low frequencies I turned it off.

Then Nathan posted about BX2, I got curious, googled a bit and I decided to mess around with it a bit.....and uh....WHOA!!!.....the results are pretty surprising...

I had to flatten my EQ and turn the gain back down to the level I had used when calibrating with the MS-8.....so I was working with the curve that the MS-8 had given me. Then I turned on BX2 and after a little trial and error I went with the lowest frequency setting of 50hz, and turned the gain down a bit. Dont know how it would measure, but it sure does sound right.

And overall Im VERY impressed, its kind of a bizarre effect but it sounds great, I can hear the sub 50hz frequencies but I cant feel them......In other words, it seems it works as advertised.

I realize how it could be "abused" and really mess things up sound wise, so I understand why you might say not to use it, but seeing as I respect your opinion.....it sure sounds good, am I missing something here.....or am I not your average customer?

[VP Electricity]

Glad it worked better in this application than I would have expected, or suggested

I guess it's basically that in my past testing (which was not with a pair of 8") that it didn't seem to help much - so I'm really hesitant to seem to be recommending it.

I was using the Mini 2 before they added the fan and BX, and them adding that feature was not any part of the reason we use it, so I'm probably just being a little guarded in case someone has the same experience I did, and complain that the button doesn't seem to work. I think that it's a free feature, in that the performance and size of that amp along with its other features justify the price, without needing the BX as part of the value proposition.

But as long as you turn it OFF before tuning the MS-8, I guess it should be fine. I would be worried that the MS algorithm might see the MaxxBass-generated notes as a peak in response which should be attenuated, so I wouldn't turn it on until after you calibrate.

When you set the freq adjustment, you are also moving a tracking high-pass filter, so below a certain point the MaxxBass IC is engaging a subsonic filter - which for a pair of 8" really ought to help out. But as far as their claims that it makes 6" door speakers sound like 8" or 10", that was never my experience.

The 125.2 gets used in a lot of motorcycle audio, and I suspect they are using the MaxxBass IC to make those 4" or 5" speakers sound better.

[jeffb335]

OK, you are confirming what I thought.....since I am using it with the Jehnerts which play strong down to about 50hz when I set the BX2 frequency all the way down to 50 it engages a highpass filter and "fakes" the frequencies below that.....thats what my reading on the subject told me and thats what my ears are telling me.

I agree that using it as a selling feature would be a bad idea as I can think of a bunch of ways for it to not work well, as I said Ive been ignoring it for a couple weeks so it wasnt part of why I got that amp.....but in my specific E92 jehnert underseat woofer/MS-8/trunk sub delete application it works pretty good......if anything it might be too good, Ive lowered my gain a couple times as the effect might be a little bit much, and ill probably tweak the midbass a tiny bit on the MS-8 to get it "just right" but as it stands now my setup sounds better than it ever has.

As someone who has been running subs for a long time its a weird sensation, I can hear the sub bass frequencies but I know that all I have is a pair of 8s so I keep waiting for something to bottom out or make some other nasty noise....but instead its nice and clean.....in fact I put my hand on the speaker grill and there was little vibration as the speakers are actually high passed.....the sub bass is an illusion.....

And as VP already mentioned, if you are reading these posts and are doing this: google "missing fundamental" if you want to know what the heck we are talking about.....

[nato-main-man-5am]

Originally Posted by jeffb335

OK, you are confirming what I thought.....since I am using it with the Jehnerts which play strong down to about 50hz when I set the BX2 frequency all the way down to 50 it engages a highpass filter and "fakes" the frequencies below that.....thats what my reading on the subject told me and thats what my ears are telling me.

I agree that using it as a selling feature would be a bad idea as I can think of a bunch of ways for it to not work well, as I said Ive been ignoring it for a couple weeks so it wasnt part of why I got that amp.....but in my specific E92 jehnert underseat woofer/MS-8/trunk sub delete application it works pretty good......if anything it might be too good, Ive lowered my gain a couple times as the effect might be a little bit much, and ill probably tweak the midbass a tiny bit on the MS-8 to get it "just right" but as it stands now my setup sounds better than it ever has.

As someone who has been running subs for a long time its a weird sensation, I can hear the sub bass frequencies but I know that all I have is a pair of 8s so I keep waiting for something to bottom out or make some other nasty noise....but instead its nice and clean.....in fact I put my hand on the speaker grill and there was little vibration as the speakers are actually high passed.....

And as VP already mentioned, if you are reading these posts and are doing this: confused2 google "missing fundamental" if you want to know what the heck we are talking about.....

Well that's very interesting. What are the settings in terms of crossovers and slopes on your ms8? I assume you are running the underseat woofers as part a "two way" front setting in the ms8?

[jeffb335]

yeah, 2 way front, xover between the underseats and door mids is 200 hz, 24db.....kind of the "go to" setting on this thread. Subsonic filter at its lowest setting, 20hz.

[VP Electricity]

There is meaningful output below 50. It's not a steep dropoff or anything.

[VP Electricity]

Originally Posted by jeffb335

OK, you are confirming what I thought.....since I am using it with the Jehnerts which play strong down to about 50hz when I set the BX2 frequency all the way down to 50 it engages a highpass filter and "fakes" the frequencies below that.....

The subsonic isn't at 50, though, if you set the knob for 50 the subsonic is somewhere below that, I'm guessing 37.5 as that's one half-octave. The subsonic tracks the setting but the value actually indicates what note you want to "emphasize".

[nato-main-man-5am]

Originally Posted by jeffb335

Hi Ken.....I was about to ask you about this....

I had tried the Arc Mini's BX2 feature a few days ago when I was experimenting but assumed at the time that it was just a bass boost (thats what it sounded like) so when I heard the over accentuated low frequencies I turned it off.

Then Nathan posted about BX2, I got curious, googled a bit and I decided to mess around with it a bit.....and uh....WHOA!!!.....the results are pretty surprising...

I had to flatten my EQ and turn the gain back down to the level I had used when calibrating with the MS-8.....so I was working with the curve that the MS-8 had given me. Then I turned on BX2 and after a little trial and error I went with the lowest frequency setting of 50hz, and turned the gain down a bit. Dont know how it would measure, but it sure does sound right.

And overall Im VERY impressed, its kind of a bizarre effect but it sounds great, I can hear the sub 50hz frequencies but I cant feel them......In other words, it seems it works as advertised.

I realize how it could be "abused" and really mess things up sound wise, so I understand why you might say not to use it, but seeing as I respect your opinion.....it sure sounds good, am I missing something here.....or am I not your average customer?

This is good/interesting to hear, but now I cannot get the 4 channel Arc like I thought I would! I gotta get the two channel with this feature, and than another amp for my fronts.... ouch! (I don't think I can adequately run my Morel's off the MS8.)

[jeffb335]

Nathan, as VP said, don't get this amp just because of the BX2 feature and don't plan on using it, if you get an arc mini get it because it is tiny, makes good power, and is of high quality. I got my setup working very well wihout BX2 and only tried it out as an experiment. As I said, I can imagine more ways for it to screw up your sound than I can think of ways for it to improve it.

VP, that makes sense, it does sound very strong in the 50hz area.....so the frequency on the knob basically is the center frequency for the effect, If the filter is a half octive lower that would be about right.....around 37hz, isnt that about where the jehnerts roll off? I'm going to be doing some driving today so I'll have some time to see if it has any weaknesses that show up in regular listening.

[nato-main-man-5am]

Good points. I'll probably go for the four channel.

[taibanl]

Originally Posted by kaigoss69

Hey man,

I read your comments on the different tunes you got with different volume levels. You spent more time at this than i ever did and I am wondering now whether i am missing this sweet spot you talked about. I want to find this sweet spot. However, one cannot use ms8 volume level as the benchmark since there are other factors affecting actual sweep volume levels, which is what really matters. Did you measure the actual dB volume of the sweeps, and what did you use to measure? Since the sweeps are so close together I think it is impossible to manually read the levels of the individual sweeps so the white noise speaker test signals during setup would probably be better to use.

Thanks

Kai

I now have all speakers externaly amped, btw. Any tips you give me would be greatly appreciated.

Ok...so the DIYMA thread always tells people to turn the sweeps down, way down, etc (-35, -40, etc). But....at one point Andy talks about the fact that the MS-8 is designed to run the sweeps at -20 WHEN THE MS-8 is the SOLE source of amplification.

Now I took this and improvised...

First I level matched my fronts (amplified) within a few dB (~3dB) of my rears. So from a SPL standpoint it was ALMOST as if my fronts were on MS-8 power. So I tried -25, -23, etc as a starting point. I then found that -21 to -23 was the sweet spot.

I will have to do this all again though with my recoding.

Note:
1) I did the level matching using the MS-8 test menu - where you can get individual channel out pink noise (instructions for accessing this are in the DIYMA FAQ thread).
2) I will try and get a dB level with my iPhone for the MS-8 channels on pink noise, that you can use as a reference point, THEN subtract your RELATIVE dB level from -20.

I.E if your SOFTEST driver is 10dB louder than mine, I would say try -30ish

[nato-main-man-5am]

I did a search of this thread, but didn't see anyone with the same setup, so I figured I'd ask.

I have the hifi system, using the MS-8 as my only amp.

I'm still running the OEM underseat woofers.

But I have replaced the door speakers with Morel Hybrid Ovations, using their passive crossover.

The Morels can play much healthier "down low" than the OEM door speakers (and the Morel tweeters appear to play lower than the OEM tweeters, using the Morel crossover).

I'm thinking I can lower my crossover between the underseat woofers and the door speakers from 150 ([old setting with OEM speakers in the doors) down to 120 or even 100hz. (I run the underseat and door speakers as a 2 way front in the config.)

My thinking is this will be more musical mid bass than the underseat woofers.

I'd love to hear others' thoughts based on their experience with Morels mated with the OEM underseat woofer in this manner.

(Yes, I know I should upgrade the underseat woofer, but it's one step at a time, and since that also means getting an amp, it will be a little while.)

[kaigoss69]

Nathan,

I went pretty low on my x-over with 150Hz. Most people use somewhere between 175 and 250Hz. It worked for me because I do not have a tendency to crank the music very loud, plus I like to think that I can detect the onsets of distortion and/or the drivers starting to play beyond their physical abilities, and make quick volume adjustments to prevent any potential damage.

The vendors would probably tell you to go to 200Hz or even higher, because they have to assume that the user is the most "irresponsible" they can think of, cranking the HU volume, the MS-8 volume, and the EQ all the way up on occasion, and the higher the crossover, the less chance of damage there is to the midrange speakers.

On the other hand, then there have been a few users who claim to have used x-overs in the 80Hz range, which in my mind is too low. A normal 4" mid can't possibly reproduce those frequencies accurately at high volume levels, there just isn't enough driver excursion available.

Also keep in mind that frequencies below 250Hz are generally not considered as "locatable", meaning most people can't tell where they are coming from. If that is the case (and I believe it is, certainly below 150Hz) then you should use a crossover frequency that is safe for the door midrange speakers, and that you know your underseat woofers can reproduce accurately.

In your case, with MS-8 "deck" power, I would say though that you may be able to go lower than 150Hz, since you are not really risking any damage to the Morels with 20W, but you do have to be careful about sending them a distorted signal, since the MS-8 will likely run out of steam easily with theses drivers, especially at lower frequencies.

EDIT: With aftermarket amp power, I would say NEVER go below 150Hz if you are responsible, and 350Hz if you have a tendency to crank it like a typical high-schooler.

[VP Electricity]

I think you can't hurt Ho4 with 16 IC watts, and that you're just playing with different flavors of suck. I think you have a pretty hard limit to the sq you can achieve with what you have, and I think that you'll look back on this and decide you were wasting your time, I'm afraid.

Yeah, vendors trying to offer bulletproof systems that don't require careful monitoring... I just thought that was good design ~

To play one octave lower with the same output from the same speaker requires 4x the excursion. So you run out of excursion quickly.

[nato-main-man-5am]

Originally Posted by kaigoss69

Nathan,

I went pretty low on my x-over with 150Hz. Most people use somewhere between 175 and 250Hz. It worked for me because I do not have a tendency to crank the music very loud, plus I like to think that I can detect the onsets of distortion and/or the drivers starting to play beyond their physical abilities, and make quick volume adjustments to prevent any potential damage.

The vendors would probably tell you to go to 200Hz or even higher, because they have to assume that the user is the most "irresponsible" they can think of, cranking the HU volume, the MS-8 volume, and the EQ all the way up on occasion, and the higher the crossover, the less chance of damage there is to the midrange speakers.

On the other hand, then there have been a few users who claim to have used x-overs in the 80Hz range, which in my mind is too low. A normal 4" mid can't possibly reproduce those frequencies accurately at high volume levels, there just isn't enough driver excursion available.

Also keep in mind that frequencies below 250Hz are generally not considered as "locatable", meaning most people can't tell where they are coming from. If that is the case (and I believe it is, certainly below 150Hz) then you should use a crossover frequency that is safe for the door midrange speakers, and that you know your underseat woofers can reproduce accurately.

In your case, with MS-8 "deck" power, I would say though that you may be able to go lower than 150Hz, since you are not really risking any damage to the Morels with 20W, but you do have to be careful about sending them a distorted signal, since the MS-8 will likely run out of steam easily with theses drivers, especially at lower frequencies.

EDIT: With aftermarket amp power, I would say NEVER go below 150Hz if you are responsible, and 350Hz if you have a tendency to crank it like a typical high-schooler.

Interesting. Well, l don't listen at particularly loud volumes, but running the low powered built in amp to clipping would be a drag, and I suppose the higher crossover would be safer in that respect.

[nato-main-man-5am]

Originally Posted by VP Electricity

I think you can't hurt Ho4 with 16 IC watts, and that you're just playing with different flavors of suck. I think you have a pretty hard limit to the sq you can achieve with what you have, and I think that you'll look back on this and decide you were wasting your time, I'm afraid.

Yeah, vendors trying to offer bulletproof systems that don't require careful monitoring... I just thought that was good design ~

To play one octave lower with the same output from the same speaker requires 4x the excursion. So you run out of excursion quickly.

Different flavors of suck! I like that.

Assuming I have a big enough amp, I could safely crossover as low as 120 hz or something, or are you saying the excursion would be problematic, even with adequate power?