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Discussion Starter #21
I value the information given and insight. I look forward to seeing further opinions on the other thread. I would be understandably thrilled if I could not only live with but possibly excel in the glass baffle door install.
 

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Discussion Starter #22
Well I took a bold move for my sq car... meet my new twins... Clarence and clary the clarus 10” in my life... one under each front seat

took a good few days to weld the chassis rail with a heavy 3mm wall box section to lower it 1.5cm, and then putting back strength I’d removed from across the car with 10mm laser cut steel baffles also, all neatly stitched into the car, it’s now stronger than it was before

I’ve literally just got the car back together after a few weeks off sorting it out...

finish on a pillar pods and enclosures to be decided as yet...

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I believe you were commenting on a thread I started 2-3 months ago about playing dash speakers low. If it was you I think I remember you saying you had 6.5’s above the dash. Bravo 🥂 looks nice. What range are they capable of playing well up there? Looks like a lot of the dash has been changed.
 

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I have rebuilt the entire dash to be non reflective, I have a phase issue at the bottom of the left hand dash mid at 135ish, damn you acoustics 🤣 the subs are crossed under seats at 85hz and down, with a generous level it fills in the gap nicely... I need to make some hoods for the subs to reduce tactile feedback at full chat, for sq competition levels you don’t really feel a thing, but it’s still a bit hot in the seat at excitable levels

It’s funny you mention this because I was in a discussion with someone the other day about kicks vs under seat, he was saying we locate midbass by itd, and kicks are as wide as any location on a car... and that’s why they are the best place for midbass... i replied with the facts that kicks aren’t the widest location by itd, doors are always wider than kicks, it’s more the depth down the car and placing the driver in the corner that makes kicks good and getting them playing down if required, but under seats done right can be equally as good for me, mine need refining somewhat but are excellent in all the ways I thought they would be

and as a bonus I’ve been working on the car for a few weeks now while off work, and I have only just integrated the rear Dayton RSS390HF into the system... it’s very clean and very windy if required, the rear will be off for Emma sq... but as a fun system it’s awesome... alon mors from my ps sound tidal playlist is awesome! I’ve been listening and flicking and extra 9db of 20hz onto the front subs 🥰 I was contemplating no back seats and a second Dayton in a flat sealed enclosure... I dont feel the need to have one right now with two clarus ten inch and a Dayton 😎
 

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Discussion Starter #24
I have rebuilt the entire dash to be non reflective, I have a phase issue at the bottom of the left hand dash mid at 135ish, damn you acoustics 🤣 the subs are crossed under seats at 85hz and down, with a generous level it fills in the gap nicely... I need to make some hoods for the subs to reduce tactile feedback at full chat, for sq competition levels you don’t really feel a thing, but it’s still a bit hot in the seat at excitable levels

It’s funny you mention this because I was in a discussion with someone the other day about kicks vs under seat, he was saying we locate midbass by itd, and kicks are as wide as any location on a car... and that’s why they are the best place for midbass... i replied with the facts that kicks aren’t the widest location by itd, doors are always wider than kicks, it’s more the depth down the car and placing the driver in the corner that makes kicks good and getting them playing down if required, but under seats done right can be equally as good for me, mine need refining somewhat but are excellent in all the ways I thought they would be. So, physically the driver can be “further” to the side but be further out from the cone of confusion. Seems all about achieving the position as close to a straight line through the ears. Good luck mounting midbass drivers in the pillars on the side of the front seats. 🤷🏼‍♂️ I’m waiting for an opportunity to read fully once I get my install squared away.


and as a bonus I’ve been working on the car for a few weeks now while off work, and I have only just integrated the rear Dayton RSS390HF into the system... it’s very clean and very windy if required, the rear will be off for Emma sq... but as a fun system it’s awesome... alon mors from my ps sound tidal playlist is awesome! I’ve been listening and flicking and extra 9db of 20hz onto the front subs 🥰 I was contemplating no back seats and a second Dayton in a flat sealed enclosure... I dont feel the need to have one right now with two clarus ten inch and a Dayton 😎
what are sq comp levels?

Did you test the mid response before you fabricated it there? Did it measure different once installed?

I have to fully read into it but do you put any faith in the ospodis theories? From the little I read it seems the woofer is best at 180* to the head, on axis to the ears if that’s the right way to say it. So, physically the driver can be “further” to the side but further out from the cone of confusion. Seems all about achieving the position as close to a straight line through the ears. Good luck mounting midbass drivers in the pillars on the side of the front seats. 🤷🏼‍♂️ I’m waiting for an opportunity to read fully once I get my install squared away.

I’m thinking about trying my hand at a local sq comp if and when one comes within an hour or two of Charleston South Carolina. I’m making surprising strides in my car audio journey and I’d like to get into a new scene with this hobby, no one I know has ever had anything like what I’m going for and no one in my circle really even understands what I’m achieving. People just say man that sounds good or man that sub hits, no one is ever like, man that images pretty good... If my car bombs in judging least I’ll get to hobnob around series audio competitors and see what is actually competitive quality. At the same time I’m achieving a lot of what I read about mattering.

I’m looking hard at the peerless sls8 for my doors now that I won the stock location battle. Any input on other drivers reasonably priced for my needs no higher then 500hz at least down to 80hz? I can provide 200 watts per channel to what ever. I’m very confident in running door IB now that I cracked the code😉
 

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Discussion Starter #25
The sls6 would be wayyy easier to mount and keep perfectly stock looking. The qts is way lower than the sls8 but people love the 6 as well in doors it seams. The 6 and 8 run into problems over 300hz?
 

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Discussion Starter #26
I don't know about the GS25, but lots of people are crossing the GB25 higher than the minimum recommendation, like 300-350 Hz or so. the GB25 is a pretty low distortion driver, but raising the crossover really lowers the distortion even more.

I would think similar would be a reasonable starting point. Practically any midbass should play that high without issues.
I'm heavily leaning towards the sls 8”. The 3-400hz GS25 highpass is concerning considering how the sls8 is described to behave above300hz.
 

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I did a quick (3hour) experiment yesterday morning. I edited the thread “interesting results” with the details. The gist is that I molded a fiberglass panel across most of my left door. I have glass and material laying around in my shop so it was easy to do. I expected a little phase improvement, maybe at best but was completely blown away.
Hopefully you all might take a look at that post and give thought on the unexpectedly great response I obtained from the stock mounting.
I've seen you mention "phase" multiple times now. How are you measuring the phase improvements?
 

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Discussion Starter #28
Audio tools app with iPhone microphone. I’m calling “phase behavior” the lack of peaks and nulls. I realize the rta im using needs a change but it is good enough to see major issues. I’m close to getting the umk-1 now that my install is nearing the end.
 

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Discussion Starter #29
I've seen you mention "phase" multiple times now. How are you measuring the phase improvements?
Isn’t it reasonable to say that the iPhone mic is decent at least in the vocal range measurement wise?
 

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Audio tools app with iPhone microphone. I’m calling “phase behavior” the lack of peaks and nulls. I realize the rta im using needs a change but it is good enough to see major issues. I’m close to getting the umk-1 now that my install is nearing the end.
Ok, well, that is really not phase at all. The peaks and nulls that you are measuring are just part of the frequency response. Phase only comes into play when multiple speakers are playing together - and how they interact with each other. So the frequency response from your left and right speakers, measured separately, could be perfect and match each other perfectly after some EQ - but then when you measure the frequency response with them both playing at the same time, that is where you would see phase issues.

As a "for example", I'll use this picture, which is an old picture of the measured frequency responses of my midbass speakers - as you can see, the left and right measurements are very close, but the "left and right combined" measurement (the green line) has big dips that don't exist when each are measured separately (at about 200hz, 400hz, 600hz) - those dips are caused by phase issues when both speakers are played together.


Now here are the same speakers, but measured after I used a few allpass filters to adjust the phase at those areas - as you can see, the dips are gone completely - without using any actual EQ boost - just adjusting the phase:


It's amazing how much of a difference an allpass filter can make if/when needed...



Isn’t it reasonable to say that the iPhone mic is decent at least in the vocal range measurement wise?
I don't know about iPhones, but I know that some Android devices use "AGC" - or "Automatic Gain Control" on their microphones, which adjust the MIC response on-the-fly. They may give a decent representation of the actual frequency response, but you are much better off with a calibrated measurement MIC - at least you know for sure. But again, none of this has anything to do with phase response. Phase is not easy to measure - the method I'm using above is just a "get close" method. To truly measure and analyze phase, you need very expensive software (such as Smaart).
 

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Discussion Starter #31
Got cha, I’ll refer to the peaks and nulls as response from now on. I thought that with reflections and baffle sound waves being involved and interacting phase was the proper term.
 

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Peaks and nulls can be the response, or they can also be a reflection/standing wave which you would see in smaart as a phase blip, so you can indeed get phase ‘errrors’ in a single driver, you just normally see them when you play them with other drivers when not using smaart 👍🏼

It’s very possible to see a phase issue, caused by a reflection or a standing wave at the listening position, often companies by a dip, it’s basically when the reflected or standing wave is more dominant so the mic picks up its phase and you get a ‘Z’ in the phase plot... you can see such a blip in my rear subwoofer vs front pair of subwoofers, where they play with any level of interaction they are perfectly in phase at the listening position... but the rear sub has a little blip at 150-180

I guess I’m trying to say don’t be so dismissive of his use of the word phase as it may just be a blip in the phase

your use of an all pass or three has just put the more dominant reflected sound in phase with the direct sounds phase either side of it as the reflected sound is more potent than the direct at those individual frequencys...

it is likely some are indeed phase, and I will also add that with midbass you should be able to get 6db of summation below about 250-300hz... 4-5db is off and out of phase/time in some respect



284163
 

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Discussion Starter #33
People refer to the front and back wave of a speaker being out of phase, and the interactions create cancellations. I guess I was using the term too freely to cover too many speaker response situations. Seems like I read other people using the term phase to describe the benefits of testing speaker locations to find the most linear response.
Correct terminology aside, Im absolutely thrilled to achieve a very workable response in my doors just by quite effectively sealing off the back wave from the cabin with a fiberglass barrier. Saved my door card and footwell floors from the cutting wheel 🎉
 

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Discussion Starter #34
I’m thinking about quitting the car audio hobby while I’m ahead. I was hoping for something a little simpler, maybe I’ll try my hand at human genome mapping, or a diy mars rocket, probably less complicated🍻
 

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I have read some on Opsodis, I read the post by P Bateman a while back. Mounting the woofers close to 180* has been in the back of my mind for a while, especially how the wavelengths around midbass need to come from the sides for the ears to sense location cues, maybe depth, something makes mounting the woofers to the sides important. I’m not trying to fight good advice from more skilled members but that floor location by the seat is really seeming to be a good solution.
As I see it, the only way to make a soundstage sound wide is to have the mids and the midbasses as wide as possible. At home, I have my speakers over three meters apart.

Basically, it's easy to 'fake' where the sound of the tweeters are coming from, but you can't fake where midrange and midbass frequencies are coming from. Where you put the mids and midbasses, that's where the sound will seem to come from.

This is because of how we perceive sound. At high frequencies, the location of sound is dictated by amplitude. At low frequencies, it's dictated by phase. In the midrange, it's both. Due to this, if one tweeter is too close to you, you can manipulate where it seems to be coming from by increasing of decreasing the amplitude. For instance, if your left tweeter is too close, you can mask that by attenuating it. If your left midbass is too close to you, you can manipulate the phase to shift the entire soundstage.

But if the midbass is in the center of the car, you're basically stuck with that. It will sound deep, but there's not much you can do to make it sound like it's somewhere else.

One caveat to this, is that multiple midbasses can do some interesting things. For instance, let's say that the door is the best location that you have to work with. But your door only fits one woofer, that's 6.5" in diameter. The typical solution is to chop up the door and squeeze an eight in there. But you could also use the stock location, and add a second 6.5" woofer in the kicks or even under the dash. 250Hz is about as long as your car is wide - it's 1.5 meters long. Because these low frequencies are so long, it's fairly easy to use multiple drivers without getting comb filtering. Multiple tweeters are a very bad idea, but multiple midbasses can work nicely. The midbasses in my Mazda are under the seat and under the dash, in bandpass boxes. I use bandpass midbasses to increase efficiency, increase power handling, reduce distortion, and widen the stage. (The apparent location of the midbass is the port, so you can move the port to widen the stage.)

 

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If you have midbasses that can fit UNDER the brake and gas pedal, one thing you might try is to mask off most of the cone.



Similar to what Nexo does with their speakers.

But instead of putting the board down the MIDDLE of the cone, just mask off 75% of the cone and leave a hole on the edge for the sound to exit through.

By doing that you'll widen the stage by about eight inches.

Masking off the cone acts like a low pass filter, the same idea as what happens with a bandpass box. So don't do this stunt if you don't have a mic, you have to take the modified output and then EQ it so it's flat. If you just mask it off without a filter, there will be a peak.

It's a neat way to manipulate where the sound appears to be coming from. You can also do weird stuff like mounting the midbasses facing DOWN, up in the dash. 250Hz is a meter and a half long, it doesn't matter if the midbass is facing you, or facing the firewall, or facing the floor, etc.

 

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Discussion Starter #37 (Edited)


As I see it, the only way to make a soundstage sound wide is to have the mids and the midbasses as wide as possible. At home, I have my speakers over three meters apart.

Basically, it's easy to 'fake' where the sound of the tweeters are coming from, but you can't fake where midrange and midbass frequencies are coming from. Where you put the mids and midbasses, that's where the sound will seem to come from.

This is because of how we perceive sound. At high frequencies, the location of sound is dictated by amplitude. At low frequencies, it's dictated by phase. In the midrange, it's both. Due to this, if one tweeter is too close to you, you can manipulate where it seems to be coming from by increasing of decreasing the amplitude. For instance, if your left tweeter is too close, you can mask that by attenuating it. If your left midbass is too close to you, you can manipulate the phase to shift the entire soundstage.

But if the midbass is in the center of the car, you're basically stuck with that. It will sound deep, but there's not much you can do to make it sound like it's somewhere else.

One caveat to this, is that multiple midbasses can do some interesting things. For instance, let's say that the door is the best location that you have to work with. But your door only fits one woofer, that's 6.5" in diameter. The typical solution is to chop up the door and squeeze an eight in there. But you could also use the stock location, and add a second 6.5" woofer in the kicks or even under the dash. 250Hz is about as long as your car is wide - it's 1.5 meters long. Because these low frequencies are so long, it's fairly easy to use multiple drivers without getting comb filtering. Multiple tweeters are a very bad idea, but multiple midbasses can work nicely. The midbasses in my Mazda are under the seat and under the dash, in bandpass boxes. I use bandpass midbasses to increase efficiency, increase power handling, reduce distortion, and widen the stage. (The apparent location of the midbass is the port, so you can move the port to widen the stage.)

Patrick, its a pleasure to have you commenting. I don’t remember how much I talked about fiberglassing my inner door in this thread but if you read through you probably saw that I was able to significantly improve the stock door location response. That being said I’m actually looking at the rss210hf to force into the door and really deaden it with a thorough glass baffle job. In reality I’m more likely to force a sls8 there. But having you chime in at the perfect time I’ll ask you about running a 6-7” midbass in each of the 4 doors. I’m really lucky that I don’t have any un fixable dips in the left door I glassed so multiple midbass locations isn’t necessary to smooth the response, but it would keep me from having to cut up the doors. But then I’d need more dsp channels, the rear door speaker location is directly below my head, almost 180* to my arss. I can probably get the extra dsp channels from a minidsp 2x4.
 

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Discussion Starter #38




If you have midbasses that can fit UNDER the brake and gas pedal, one thing you might try is to mask off most of the cone.



Similar to what Nexo does with their speakers.

But instead of putting the board down the MIDDLE of the cone, just mask off 75% of the cone and leave a hole on the edge for the sound to exit through.

By doing that you'll widen the stage by about eight inches.

Masking off the cone acts like a low pass filter, the same idea as what happens with a bandpass box. So don't do this stunt if you don't have a mic, you have to take the modified output and then EQ it so it's flat. If you just mask it off without a filter, there will be a peak.

It's a neat way to manipulate where the sound appears to be coming from. You can also do weird stuff like mounting the midbasses facing DOWN, up in the dash. 250Hz is a meter and a half long, it doesn't matter if the midbass is facing you, or facing the firewall, or facing the floor, etc.



In case you would be interested in what I tried and successfully accomplished last week. The whole topic is interesting, to me at least but the fiberglass door baffle was delightfully effective in the second half.
 
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