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post #3001 of 4067 Old 08-03-2019, 10:15 AM - Thread Starter
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Originally Posted by Longeze View Post
I was hoping that maybe someone with a single seat setup(for eg.) might be curious enough to pop for the $8.00 to buy a bicycle innertube to do a comparison.. in the name of "science" don't you know

Since as you might imagine, my performance expectations for the innertube/sealed drivers vs silicone isolators are the same as your own, buying & mounting all the isolators required to support our "elephant" Hovercouch, would defeat the economy that partially motivated the use of the innertubes to begin with, while most likely providing little in the way of ROI.

Missing Link: Don't expect "The Incredibles" or anything, but it's a passably entertaining movie with exceptional TR. Please post up with your thoughts after you check it out. I'd be interested to get your take on it.
Longeze.....Thanks....I'll definitely check it out and post afterwards. Yeah, I'm in agreement on the isos.....you'll probably only need 4 based on my experience but that's still $25 that won't be needed given your setup today with the tubes and sealed arrangement like you have. I may give the tubes a try on our mini-riser this winter when things tend to slow down around the house. Looking forward to experimenting again!
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post #3002 of 4067 Old 08-04-2019, 04:29 PM
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I'd really like to try a mini-riser under my row-of-3 recliners, but there are some challenges due to the internal construction of the recliners. The entire metal frame of the recliners with cross-braces rests on the ground which forces the placement of the woofer at the rear of the seat. In fact the driver and mini-riser baffle will have to protrude about 4" past the rear of the recliner which by itself isn't really a problem. The problem is there is a horizontal wooden brace at the rear of the seat which only has a 4.5" clearance above the floor (or top of baffle once installed). As the seat is power-reclined, this brace will sweep over the woofer position (seems to have the same 4.5" clearance throughout its sweep range).

Given the 6 1/16" mounting depth of the recommended JBL drivers, I'm at a no-go without one of the following modifications, each having its own downside:
  1. Add an additional 3/4" spacer between the driver and the bottom side of the baffle. This will make the overall mini-riser height 2.5" which is probably higher than I want to go.
  2. Cut out a 3/4" x (motor width) notch in the seat's horizontal brace to allow clearance. The overall height of the brace is 4", so losing 3/4" might ok, and I could add some metal bracing to reinforce above the notch.
  3. Go with another driver with a lower profile. So far this Dayton 12" driver looks similar performance-wise, but has slightly less excursion (10mm vs 12mm), higher Fs (33 vs 28 Hz), lower sensitivity (88 vs 90 dB). It also costs more, but is in my price range.

If anyone has any other suggestions or know of a lower-profile woofer that has better cost/performance, please let me know. Any mounting depth less than 5.25" should work.

Thanks,
Darrell
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post #3003 of 4067 Old 08-04-2019, 06:01 PM - Thread Starter
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Originally Posted by darrellh44 View Post
I'd really like to try a mini-riser under my row-of-3 recliners, but there are some challenges due to the internal construction of the recliners. The entire metal frame of the recliners with cross-braces rests on the ground which forces the placement of the woofer at the rear of the seat. In fact the driver and mini-riser baffle will have to protrude about 4" past the rear of the recliner which by itself isn't really a problem. The problem is there is a horizontal wooden brace at the rear of the seat which only has a 4.5" clearance above the floor (or top of baffle once installed). As the seat is power-reclined, this brace will sweep over the woofer position (seems to have the same 4.5" clearance throughout its sweep range).

Given the 6 1/16" mounting depth of the recommended JBL drivers, I'm at a no-go without one of the following modifications, each having its own downside:
  1. Add an additional 3/4" spacer between the driver and the bottom side of the baffle. This will make the overall mini-riser height 2.5" which is probably higher than I want to go.
  2. Cut out a 3/4" x (motor width) notch in the seat's horizontal brace to allow clearance. The overall height of the brace is 4", so losing 3/4" might ok, and I could add some metal bracing to reinforce above the notch.
  3. Go with another driver with a lower profile. So far this Dayton 12" driver looks similar performance-wise, but has slightly less excursion (10mm vs 12mm), higher Fs (33 vs 28 Hz), lower sensitivity (88 vs 90 dB). It also costs more, but is in my price range.

If anyone has any other suggestions or know of a lower-profile woofer that has better cost/performance, please let me know. Any mounting depth less than 5.25" should work.

Thanks,
Darrell
Darrell....Thanks for the details of your setup. The MBQuart DS1-304 is 3.5" in height and has been used successfully for BOSS applications by other members.

A list of alternate BOSS drivers including the MBQuart is located in Post 2150 with a hyperlink here

@Archaea has mounted one of these drivers under each of his recliners with the BOSS platform directly mounted to his frames and has reported great results.

Here's a hyperlink to his BOSS build here

The cool thing about this driver is it only needs about 20-30 watts to reach full excursion......here's a link to the WinISD model and comparison of the DS1-304 to the baseline JBL right here

When I get to a computer tomorrow, I'll model the Dayton Audio driver you mentioned above and see how it compares to the baseline JBL also.

As always, as your design comes into focus just let us know of any other questions.

Hope this helps.
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post #3004 of 4067 Old 08-04-2019, 07:12 PM
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Just curious if I missed this in the thread, but it appears that Best Buy no longer sells the subs.

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post #3005 of 4067 Old 08-04-2019, 07:29 PM
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Originally Posted by plain fan View Post
Just curious if I missed this in the thread, but it appears that Best Buy no longer sells the subs.
You mean the JBL subs?

https://www.bestbuy.com/site/jbl-gx-...skuId=62836434
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post #3006 of 4067 Old 08-05-2019, 05:22 AM
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@darrellh44 , I have one of the MBQuart DS1-304 mounted directly to the underside of my sectional. It drives fairly easy for sure as @trhought has indicated. I sometimes think maybe I should have just bought 2 or3 and just built a mini riser. Maybe once they go on sale again, I will get upgraditus?
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post #3007 of 4067 Old 08-05-2019, 11:35 AM - Thread Starter
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Quote:
Originally Posted by darrellh44 View Post
I'd really like to try a mini-riser under my row-of-3 recliners, but there are some challenges due to the internal construction of the recliners. The entire metal frame of the recliners with cross-braces rests on the ground which forces the placement of the woofer at the rear of the seat. In fact the driver and mini-riser baffle will have to protrude about 4" past the rear of the recliner which by itself isn't really a problem. The problem is there is a horizontal wooden brace at the rear of the seat which only has a 4.5" clearance above the floor (or top of baffle once installed). As the seat is power-reclined, this brace will sweep over the woofer position (seems to have the same 4.5" clearance throughout its sweep range).

Given the 6 1/16" mounting depth of the recommended JBL drivers, I'm at a no-go without one of the following modifications, each having its own downside:
[*]Go with another driver with a lower profile. So far this Dayton 12" driver looks similar performance-wise, but has slightly less excursion (10mm vs 12mm), higher Fs (33 vs 28 Hz), lower sensitivity (88 vs 90 dB). It also costs more, but is in my price range.

If anyone has any other suggestions or know of a lower-profile woofer that has better cost/performance, please let me know. Any mounting depth less than 5.25" should work.

Thanks,
Darrell
Darrel....below is a comparison of the Dayton Audio driver, the baseline JBL and the MBQuart which is the other low profile driver that others have tried and reported great results. Red is the Dayton driver, Blue is the baseline JBL and Green is the MBQuart.

This is showing the cone excursion in an open baffle configuration. From the chart, the JBL and Dayton drivers behave similar in response. The MBQuart is a bit more peaky around 20 Hz and drops off in response above 30 Hz which can be helpful with TR.

For power, the JBL and Dayton drivers will both take about 50 watts to reach Xmax. The JBL can take another 30 watts or so to reach Xmech of 15mm. The Dayton driver can probably take more power also. If Xmech of the Dayton is known, that additional power can be calculated also. The MBQuart will only take about 20-30 watts to reach Xmax.

So, it really depends on goals for your BOSS design. If you'll have a very rigid platform and additional holes cut into it won't reduce that rigidity, the MBQuarts will allow more drivers to be used for the same power as the JBL's or Daytons so you'll get more shaker potential by using the MBQuarts.

However, if power isn't limited, then using the Daytons will offer about 15-20% more shaker potential than the MBQuart if keeping the number of drivers the same.

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post #3008 of 4067 Old 08-05-2019, 11:45 AM - Thread Starter
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Originally Posted by plain fan View Post
Just curious if I missed this in the thread, but it appears that Best Buy no longer sells the subs.
Just checked the BB website and it looks like both the GX-1200 and CX-1200 are still being sold. Walmart also sells the CS-1214 and it's showing 2 are available in my area for $45 each. These are all the same JBL driver, just a different dust cap.

So, it looks like they're still being sold in the US. Just keep checking here for sales....someone always updates when sales are available.

The last sale was at BB for the GX1200 a couple weeks ago and they were on sale for the normal on-sale price of $29.99
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post #3009 of 4067 Old 08-05-2019, 06:46 PM
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Thanks guys! I did a search on their website but no results came back.

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post #3010 of 4067 Old 08-05-2019, 10:24 PM
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Originally Posted by trhought View Post
Darrel....below is a comparison of the Dayton Audio driver, the baseline JBL and the MBQuart which is the other low profile driver that others have tried and reported great results. Red is the Dayton driver, Blue is the baseline JBL and Green is the MBQuart.

This is showing the cone excursion in an open baffle configuration. From the chart, the JBL and Dayton drivers behave similar in response. The MBQuart is a bit more peaky around 20 Hz and drops off in response above 30 Hz which can be helpful with TR.

For power, the JBL and Dayton drivers will both take about 50 watts to reach Xmax. The JBL can take another 30 watts or so to reach Xmech of 15mm. The Dayton driver can probably take more power also. If Xmech of the Dayton is known, that additional power can be calculated also. The MBQuart will only take about 20-30 watts to reach Xmax.

So, it really depends on goals for your BOSS design. If you'll have a very rigid platform and additional holes cut into it won't reduce that rigidity, the MBQuarts will allow more drivers to be used for the same power as the JBL's or Daytons so you'll get more shaker potential by using the MBQuarts.

However, if power isn't limited, then using the Daytons will offer about 15-20% more shaker potential than the MBQuart if keeping the number of drivers the same.

Hi Tim,

Thanks for the feedback and detailed comparisons between the drivers. Since you mentioned that the Daytons should work well if my platform baffle is sufficiently rigid, I think I'll go that route. Unfortunately I haven't been able to find a spec on the Dayton's Xmech, so I'll have to be careful.

Attached is a picture of one of the recliner's base (front of recliner is on the right). It shows the heavy metal framing that normally rests on the floor. I should be able to bolt the BOSS baffle directly to this metal framework in several places on each of the recliners. This should help make the baffle very rigid and tightly coupled to the seat frames. All 3 recliners will be mounted on a single baffle. I plan to mount a driver at the rear of each seat (left side in pic). With all of the seat's cross bracing, I don't think I could fit any more than 3.

I have a question about the number and placement of the recommended Isos. I assume I need at least a pair of Isos located at either end of the platform, and another pair between each seat. Since most of the weight will be centered close to drivers in the rear, should additional Isos be added around each driver?

Thanks for your help,
Darrell
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post #3011 of 4067 Old 08-06-2019, 11:16 AM
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Originally Posted by darrellh44 View Post
I plan to mount a driver at the rear of each seat (left side in pic). With all of the seat's cross bracing, I don't think I could fit any more than 3.
Darrell
You should get a speaker to actually see and make a decision on how to plan. Having the speaker on hand changes you plan like it did with mine

Quote:
Originally Posted by darrellh44 View Post
I have a question about the number and placement of the recommended Isos. I assume I need at least a pair of Isos located at either end of the platform, and another pair between each seat. Since most of the weight will be centered close to drivers in the rear, should additional Isos be added around each driver?
Darrell
You can look at the current feet it already has, and compliment similarly.

Good luck with your BOSS.
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post #3012 of 4067 Old 08-06-2019, 04:00 PM - Thread Starter
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Originally Posted by darrellh44 View Post
Hi Tim,

Thanks for the feedback and detailed comparisons between the drivers. Since you mentioned that the Daytons should work well if my platform baffle is sufficiently rigid, I think I'll go that route. Unfortunately I haven't been able to find a spec on the Dayton's Xmech, so I'll have to be careful.

Attached is a picture of one of the recliner's base (front of recliner is on the right). It shows the heavy metal framing that normally rests on the floor. I should be able to bolt the BOSS baffle directly to this metal framework in several places on each of the recliners. This should help make the baffle very rigid and tightly coupled to the seat frames. All 3 recliners will be mounted on a single baffle. I plan to mount a driver at the rear of each seat (left side in pic). With all of the seat's cross bracing, I don't think I could fit any more than 3.

I have a question about the number and placement of the recommended Isos. I assume I need at least a pair of Isos located at either end of the platform, and another pair between each seat. Since most of the weight will be centered close to drivers in the rear, should additional Isos be added around each driver?

Thanks for your help,
Darrell
Darrell....Thanks....good questions. Some members have used a tupperware bowl or similar "cone" they had around the house that matches the dimensions of the driver they want. As aravindhan mentioned, the easiest way is to get the drivers and place them under your seats then slowly lower them to see where they fit best. After a few fitment trials you'll get a good idea to on location and number of drivers that can be accommodated.

For the isos, if you're platform is very rigid, you may be able to use just 4 on the corners. If there's some platform flexing when fully loaded, then placing one in the middle of the platform will mitigate that bending. Also, if you have thick carpet and thick carpet padding, it may be necessary to purchase the carpet savers to place under each isolator to allow enough clearance between the face of the drivers and the carpet for "breathing room"...about .5" of breathing room will be good.

Something like the carpet savers in the link below have been used successfully in other BOSS builds.

Hope this helps.

Link to furniture savers

https://www.amazon.com/Slipstick-CB4...ateway&sr=8-13
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post #3013 of 4067 Old 08-06-2019, 04:49 PM
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Originally Posted by trhought View Post
Darrell....Thanks....good questions. Some members have used a tupperware bowl or similar "cone" they had around the house that matches the dimensions of the driver they want. As aravindhan mentioned, the easiest way is to get the drivers and place them under your seats then slowly lower them to see where they fit best. After a few fitment trials you'll get a good idea to on location and number of drivers that can be accommodated.
It's hard to tell from the recliner bottom view I posted earlier, but it would be difficult to locate even a 6" driver anywhere except behind the last cross bar. Everywhere else there is a grid of ground-level framing that supports the seat and power-recline mechanism. I can get a 12" driver behind the last crossbar, but I'll need the baffle and driver to extend beyond the rear of the recliner by 4"-5". I'm ok with this aesthetically. This placement also seems practical since when the seat is reclined, the listener's rear-end (and center of overall weight distribution) will be almost directly above the where the shaking is being generated.

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Originally Posted by trhought View Post
For the isos, if you're platform is very rigid, you may be able to use just 4 on the corners. If there's some platform flexing when fully loaded, then placing one in the middle of the platform will mitigate that bending. Also, if you have thick carpet and thick carpet padding, it may be necessary to purchase the carpet savers to place under each isolator to allow enough clearance between the face of the drivers and the carpet for "breathing room"...about .5" of breathing room will be good.
Is the goal to add as few Isos as possible? Even though all 3 recliners will be attached to the same baffle, the seats themselves are not connected together, so I'm pretty sure they will need some floor support between the 3 seats to prevent sagging. Also the Hudson site says each 1.25" Iso pad only supports 5-19 lbs per pad which means a whole lot of Isos if that spec means anything for our application. I accept the experience of what others have found, but is there some upper limit you'd suggest for the number of Isos?

I do have thicker carpet and matting, so I'm already planning on using the suggested carpet savers under the Isos.

Thanks,
Darrell

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post #3014 of 4067 Old 08-06-2019, 05:10 PM - Thread Starter
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It's hard to tell from the recliner bottom view I posted earlier, but it would be difficult to locate even a 6" driver anywhere except behind the last cross bar. Everywhere else there is a grid of ground-level framing that supports the seat and power-recline mechanism. I can get a 12" driver behind the last crossbar, but I'll need the baffle and driver to extend beyond the rear of the recliner by 4"-5". I'm ok with this aesthetically. This placement also seems practical since when the seat is reclined, the listener's rear-end (and center of overall weight distribution) will be almost directly above the where the shaking is being generated.

Is the goal to add as few Isos as possible? Even though all 3 recliners will be attached to the same baffle, the seats themselves are not connected together, so I'm pretty sure they will need some floor support between the 3 seats to prevent sagging. Also the Hudson site says each 1.25" Iso pad only supports 5-19 lbs per pad which means a whole lot of Isos if that spec means anything for our application. I accept the experience of what others have found, but is there some upper limit you'd suggest for the number of Isos?

I do have thicker carpet and matting, so I'm already planning on using the suggested carpet savers under the Isos.

Thanks,
Darrell
Darrell....Thanks for the reminder on the cantilevered location for your drivers. With the cantilever design just follow the guidelines in Post 29 that point to the proper location for the isolators for a cantilever design (carp's cantilever BOSS in particular)....that diagram is in post 323 and linked below also.

Basically, instead of having the back isolators directly below the back chair legs, you'll want to move those back isolators behind the centerline of the drivers so the driver motion gets translated naturally to the BOSS platform. This back isolator placement mitigates the platform bending that would normally happen with any cantilever.

If you're platform is a double layer plywood design or has stiffening ribs or metal supports, the platform may not deflect when everyone is sitting on it. If it does deflect, just 1 isolator in the middle should be sufficient. Yes, the goal is a totally "floaty" platform which means less isolators, the better. With mini-risers and the tendancy for those single sheets to be rather flimsy, the isolators serve the purpose of minimizing bending and should be used sparingly only where obvious bending is occurring.

The full size risers don't have the bending problem and those designs typically don't use many isolators at all....I'm only using 4 on my 1,800 lb full size BOSS riser for the back row. The key is the durometer which is important in a dynamic system. The force those isolators provide are less important with the low dynamic displacements we're talking about with TR.

Hope this helps.

Link to isolator placement for cantilevered BOSS designs
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post #3015 of 4067 Old 08-06-2019, 11:29 PM
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Hello BOSS builders. I am wanting to try BOSS technology myself so I will begin on the project. Because there is just a small space beneath MLP my plan is to use the MB Quart subs that are talked about so maybe around 3 of those. I have normal miniDSP already for fine tuning a natural crossover for the sub. Besides from some wires I just need to decide about the amplifier, so what power requirement do I need to look for??
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post #3016 of 4067 Old 08-07-2019, 05:41 AM
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Just sharing my experience on the iso’s. My platforms are 3 sheets thick, so extremely rigid, but also heavy. The chairs are nearly 100lbs, platform at least 40lbs, 15” driver at least 25lbs, and I’m at least 210lbs. I started with 4 iso’s and noticed the gap between the platform and floor kept shrinking. I went to 6 and the gap remains at the proper height, PLUS the platform is now even more wobbly.

The iso’s weren’t compressing when only 4, but the furniture sliders they were on top of were and they were digging deeper into the carpet. 6 distributed the weight better, preventing that slider and carpet sag.
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post #3017 of 4067 Old 08-07-2019, 06:41 AM - Thread Starter
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Hello BOSS builders. I am wanting to try BOSS technology myself so I will begin on the project. Because there is just a small space beneath MLP my plan is to use the MB Quart subs that are talked about so maybe around 3 of those. I have normal miniDSP already for fine tuning a natural crossover for the sub. Besides from some wires I just need to decide about the amplifier, so what power requirement do I need to look for??
gmm....welcome to BOSS thread. Fortunately, for the MB Quart subs, those will only need about 20-30 watts RMS and can be wired for 2 ohms or 8 ohms, so there's many options for wiring depending on what amp you select. For the amplifier, any stereo amplifier that can be bridged will work since the power requirements are so low with the MBQuarts. If you have a spare amplifier or AVR around the house, other members have successfully used these to power their BOSS platforms.

Since you're looking at a 3 sub platform, I mentioned bridged amplifier above because it will be best to drive those 3 off one channel. If you have 4 subs, you can split those and have 2 drivers per channel on your stereo amplifier.

Hope this helps and as always, let us know as your design comes into focus and more questions come up.

Welcome aboard!
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post #3018 of 4067 Old 08-07-2019, 11:41 AM - Thread Starter
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@gmmW8P8Adz Forgot to mention in my post above....if you have a stereo amplifer or can get one with 100 watts RMS per channel, you could just use one of those channels to drive 3 of the MBQuarts since they only need about 20-30 watts RMS each.

Something like the amplifier linked below could be used for either a 3 MBQuart BOSS platform (3 subs on one circuit running the amp in mono mode) or a 4 MBQuart BOSS platform (running 2 on each channel with the amp in stereo mode).

https://www.amazon.com/Audio-Source-...QAJMNVG1WK8P95
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post #3019 of 4067 Old 08-07-2019, 11:47 AM - Thread Starter
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Originally Posted by SteveCallas View Post
Just sharing my experience on the iso’s. My platforms are 3 sheets thick, so extremely rigid, but also heavy. The chairs are nearly 100lbs, platform at least 40lbs, 15” driver at least 25lbs, and I’m at least 210lbs. I started with 4 iso’s and noticed the gap between the platform and floor kept shrinking. I went to 6 and the gap remains at the proper height, PLUS the platform is now even more wobbly.

The iso’s weren’t compressing when only 4, but the furniture sliders they were on top of were and they were digging deeper into the carpet. 6 distributed the weight better, preventing that slider and carpet sag.
That's a good point Steve about the carpet and carpet padding sag over time which can take away from the platform "floatiness" after a few months.

Other members have reported good results when using the carpet savers linked below....these have small spikes on the bottom that poke through the carpet and padding getting the load distributed on the subfloor rather than on top of the carpet and padding.

I'm going to add these to Post 29 also for those with thick carpet and padding.

Link to carpet savers for those with thick carpet and padding

https://www.amazon.com/Slipstick-CB4...ateway&sr=8-13
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post #3020 of 4067 Old 08-07-2019, 12:02 PM
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@gmmW8P8Adz Forgot to mention in my post above....if you have a stereo amplifer or can get one with 100 watts RMS per channel, you could just use one of those channels to drive 3 of the MBQuarts since they only need about 20-30 watts RMS each.

Something like the amplifier linked below could be used for either a 3 MBQuart BOSS platform (3 subs on one circuit running the amp in mono mode) or a 4 MBQuart BOSS platform (running 2 on each channel with the amp in stereo mode).

https://www.amazon.com/Audio-Source-...QAJMNVG1WK8P95


I'm running my 3 MBQuarts from my old but still very good Denon 3808 receiver.
I took the sub out (<80hz) from my new prepro and put it into an empty analog input on the Denon. I then set the Denon to play the same signal to all the connected channels (ie. 7ch stereo if I remember correctly). Each MBQuart driver is then connected to an individual channel on the receiver. I can then adjust the BOSS to be as strong as I like or even fully off just to compare the performance with/without the BOSS running.
More speaker wire is used but I like the easy load on the amp and the flexibility in setting individual levels.
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post #3021 of 4067 Old 08-07-2019, 05:06 PM - Thread Starter
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^^^ Great use of an old AVR! @EricE
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post #3022 of 4067 Old 08-07-2019, 08:14 PM
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Originally Posted by trhought View Post
gmm....welcome to BOSS thread. Fortunately, for the MB Quart subs, those will only need about 20-30 watts RMS and can be wired for 2 ohms or 8 ohms, so there's many options for wiring depending on what amp you select. For the amplifier, any stereo amplifier that can be bridged will work since the power requirements are so low with the MBQuarts. If you have a spare amplifier or AVR around the house, other members have successfully used these to power their BOSS platforms.

Since you're looking at a 3 sub platform, I mentioned bridged amplifier above because it will be best to drive those 3 off one channel. If you have 4 subs, you can split those and have 2 drivers per channel on your stereo amplifier.

Hope this helps and as always, let us know as your design comes into focus and more questions come up.

Welcome aboard!
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Originally Posted by trhought View Post
@gmmW8P8Adz Forgot to mention in my post above....if you have a stereo amplifer or can get one with 100 watts RMS per channel, you could just use one of those channels to drive 3 of the MBQuarts since they only need about 20-30 watts RMS each.

Something like the amplifier linked below could be used for either a 3 MBQuart BOSS platform (3 subs on one circuit running the amp in mono mode) or a 4 MBQuart BOSS platform (running 2 on each channel with the amp in stereo mode).

https://www.amazon.com/Audio-Source-...QAJMNVG1WK8P95
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Originally Posted by EricE View Post
I'm running my 3 MBQuarts from my old but still very good Denon 3808 receiver.
I took the sub out (<80hz) from my new prepro and put it into an empty analog input on the Denon. I then set the Denon to play the same signal to all the connected channels (ie. 7ch stereo if I remember correctly). Each MBQuart driver is then connected to an individual channel on the receiver. I can then adjust the BOSS to be as strong as I like or even fully off just to compare the performance with/without the BOSS running.
More speaker wire is used but I like the easy load on the amp and the flexibility in setting individual levels.
Thank You for the advice. Really great that MB Quart needs just a little power for BOSS technology. Because I did not have the old equipment I will just try to find some pretty good quality 100 RMS amplifier. Why a pretty good quality even if BOSS technology just need normal quality?? Because maybe later we can choose that to play another thing. Anyway as well it is connecting to the high quality equipment so really we do not want him to make electrical trouble for them. But it is hard to find it, always the high quality is just a little power.. the bad quality is a lots of power. Nobody selling normal power.
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post #3023 of 4067 Old 08-08-2019, 06:40 AM - Thread Starter
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Originally Posted by gmmW8P8Adz View Post
Thank You for the advice. Really great that MB Quart needs just a little power for BOSS technology. Because I did not have the old equipment I will just try to find some pretty good quality 100 RMS amplifier. Why a pretty good quality even if BOSS technology just need normal quality?? Because maybe later we can choose that to play another thing. Anyway as well it is connecting to the high quality equipment so really we do not want him to make electrical trouble for them. But it is hard to find it, always the high quality is just a little power.. the bad quality is a lots of power. Nobody selling normal power.
gmm.....That's a good approach to purchase a pretty good 100 watt RMS per channel amplifier if you don't have any extras today. Always good to have a good quality amp on hand for another project down the road, such as adding another far field subwoofer.

If you're looking for more power for more projects down the road such as another far field subwoofer, it's hard to beat the Behringer NX3000/6000D models. If you got one of those, you could power a 3 or 4 driver BOSS platform on 1 channel and use the other channel for your second far field subwoofer in the future. Just make sure to get the DSP model (the D at the end of the model number) so you can limit the power to the MBQuart BOSS subwoofers since they only need about 30 watts each.

As always, as your design comes into focus, just let us know of any questions.
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post #3024 of 4067 Old 08-08-2019, 01:56 PM
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First off - This is BOSS idea is super cool and exciting. The last thing I've wanted to add to my theater is some kind of TR.. I heard some iffy things about a lot of the methods.. I've read great things about Crawsons - they've just been a little on the pricy side - and I upgraded other things first.. I was actually searching to see if Crawson had updated their product line when I stumbled upon BOSS.. And it seems like it's damn near the performance for a fraction of the cost - which is right up my ally.. It's really brilliant that you all came up with this - I'm super grateful that I get to piggyback on your great idea!


Second, I'm sorry if any of these questions are redundant - I've been reading the thread off an on for the past couple days.. I could've very easily missed the answers..


OK - off to the questions!


1) I have three chairs that span about 89"x32" - I plan to only construct a mini BOSS platform to sit directly under the chairs, so roughly the same dimensions. I want to put a driver under each chair. I'm considering doubling up the 3/4" MDF underneath.. But, I'm wondering if that is over kill? Or, if there's a downside to doubling up the MDF?


2) I've read some mentions of doubling up the isolators - but, the recommended isolators are hemispheres.. does doubling them increase their effectiveness for a regular mini BOSS design? If yes, how should one best double them? https://www.amazon.com/Platinum-Sili...rum-convert-20


3) how often do the drivers go on sale for $29.99? I read a sale just happened a few weeks back..


4) I notice that when recommending the Behringer amp, it's important to get the D model so you can limit the juice going to the drivers.. How do you make sure you don't push them too hard if you're using a more conventional amp like this: https://www.amazon.com/Audio-Source-...QAJMNVG1WK8P95


5) I see the speaker mounting diameter for the JBLs is 11" - this is a stupid question, but I've never cut my own baffle, before - that's just an 11" diameter cutout, right? Any tricks for getting it cut exactly right? I've got a router and a circular router jig..


6) Just to double check - it's not necessary to flush mount the drivers in the mini BOSS as long as the recommended isolators + carpet savers are used, right? I just want to make sure I'm not running the driver into the ground..


Thanks in advance - I'm so stoked to give this a shot.
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post #3025 of 4067 Old 08-08-2019, 02:18 PM
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Originally Posted by thedudexxi View Post
First off - This is BOSS idea is super cool and exciting. The last thing I've wanted to add to my theater is some kind of TR.. I heard some iffy things about a lot of the methods.. I've read great things about Crawsons - they've just been a little on the pricy side - and I upgraded other things first.. I was actually searching to see if Crawson had updated their product line when I stumbled upon BOSS.. And it seems like it's damn near the performance for a fraction of the cost - which is right up my ally.. It's really brilliant that you all came up with this - I'm super grateful that I get to piggyback on your great idea!


Second, I'm sorry if any of these questions are redundant - I've been reading the thread off an on for the past couple days.. I could've very easily missed the answers..


OK - off to the questions!


1) I have three chairs that span about 89"x32" - I plan to only construct a mini BOSS platform to sit directly under the chairs, so roughly the same dimensions. I want to put a driver under each chair. I'm considering doubling up the 3/4" MDF underneath.. But, I'm wondering if that is over kill? Or, if there's a downside to doubling up the MDF?


2) I've read some mentions of doubling up the isolators - but, the recommended isolators are hemispheres.. does doubling them increase their effectiveness for a regular mini BOSS design? If yes, how should one best double them? https://www.amazon.com/Platinum-Sili...rum-convert-20


3) how often do the drivers go on sale for $29.99? I read a sale just happened a few weeks back..


4) I notice that when recommending the Behringer amp, it's important to get the D model so you can limit the juice going to the drivers.. How do you make sure you don't push them too hard if you're using a more conventional amp like this: https://www.amazon.com/Audio-Source-...QAJMNVG1WK8P95


5) I see the speaker mounting diameter for the JBLs is 11" - this is a stupid question, but I've never cut my own baffle, before - that's just an 11" diameter cutout, right? Any tricks for getting it cut exactly right? I've got a router and a circular router jig..


6) Just to double check - it's not necessary to flush mount the drivers in the mini BOSS as long as the recommended isolators + carpet savers are used, right? I just want to make sure I'm not running the driver into the ground..


Thanks in advance - I'm so stoked to give this a shot.

Having recently completed my own mini boss riser, I will attempt to answer some of your questions, though I'm sure others more experienced than I will chime in as well.


1. Those dimensions should be fine for your BOSS build. I have seen some excellent examples where people have doubled up on 3/4" plywood, so that is definitely a good option with that width/size and not overkill.


2. I don't think you need to double up on isolators. If you get the recommended ones you should be fine, as long as you space them no more than 2 feet apart from left to right and front to back you should be fine.


3. I don't think they go on sale for $29.99 very often, and it's been rumored that they may never go on sale for that amount again. You could wait, but it might be a long wait.


4. With the amp you are looking at, I don't think you need to worry too much about limiting. I am running mine off of an Outlaw 5000 amp and each channel gets 120 watts (so 60 watts per driver) and I have no limiter on it and it works just fine.


5. I used the styrofoam insert that comes with the JBL subwoofers as a template for marking my circles on the board, and it worked out pretty well. Might be worth a try or you could just measure it out once you get the subs. I posted a pic or two of it in this thread on page 99 or so.


6. I don't think it's necessary to flush mount as long as you have enough isos to keep it about a 1/2" off of the ground when people are seated (basically if you can fit your finger under the board when there's weight on the board, that should be enough clearance).


Hopefully this helps, and hopefully others will respond to help give you clarification on those questions. Good luck with your BOSS build!

Last edited by m0j0; 08-08-2019 at 06:09 PM.
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post #3026 of 4067 Old 08-08-2019, 05:56 PM - Thread Starter
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Having recently completed my own mini boss riser, I will attempt to answer some of your questions, though I'm sure others more experienced than I will chime in as well.


5. I used the styrofoam insert that comes with the JBL subwoofers as a template for marking my circles on the board, and it worked out pretty well. Might be worth a try or you could just measure it out once you get the subs. I posted a pic or two of it in this thread on page 99 or so.


6. I don't think it's necessary to flush mount as long as you have enough isos to keep it about a 1/2" on the ground when people are seated (basically if you can fit your finger under the board when there's weight on the board, that should be enough clearance).


Hopefully this helps, and hopefully others will respond to help give you clarification on those questions. Good luck with your BOSS build!
m0j0...great idea for number 5! Wish I would have thought of that instead of using a ruler with a hole in it

@thedudexxi For number 6, yes, as m0j0 suggested, no need to flush mount. The key is to provide about a .5" gap between the face of the JBL's and the floor beneath. If you have thick carpet and thick carpet padding, you may need to also buy the carpet savers linked in Post 29. These have spikes on the bottom of them that poke through the carpet and padding to get closer to the subfloor. This will allow a solid foundation for your BOSS isolators to rest on top of and also maintain the needed .5" clearance for the JBL's to breath.

Hope this helps and welcome aboard!
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post #3027 of 4067 Old 08-09-2019, 05:25 AM
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Originally Posted by m0j0 View Post
Having recently completed my own mini boss riser, I will attempt to answer some of your questions, though I'm sure others more experienced than I will chime in as well.


1. Those dimensions should be fine for your BOSS build. I have seen some excellent examples where people have doubled up on 3/4" plywood, so that is definitely a good option with that width/size and not overkill.


2. I don't think you need to double up on isolators. If you get the recommended ones you should be fine, as long as you space them no more than 2 feet apart from left to right and front to back you should be fine.


3. I don't think they go on sale for $29.99 very often, and it's been rumored that they may never go on sale for that amount again. You could wait, but it might be a long wait.


4. With the amp you are looking at, I don't think you need to worry too much about limiting. I am running mine off of an Outlaw 5000 amp and each channel gets 120 watts (so 60 watts per driver) and I have no limiter on it and it works just fine.


5. I used the styrofoam insert that comes with the JBL subwoofers as a template for marking my circles on the board, and it worked out pretty well. Might be worth a try or you could just measure it out once you get the subs. I posted a pic or two of it in this thread on page 99 or so.


6. I don't think it's necessary to flush mount as long as you have enough isos to keep it about a 1/2" off of the ground when people are seated (basically if you can fit your finger under the board when there's weight on the board, that should be enough clearance).


Hopefully this helps, and hopefully others will respond to help give you clarification on those questions. Good luck with your BOSS build!
Thanks for the input - that definitely helped clarify a lot of questions I had.


I did have a follow up on the first couple questions, though.


I've been reading that the stiffer the platform - the less isolators are necessary. Then - would doubling up the MDF mean I would use less isolators for optimum results?
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post #3028 of 4067 Old 08-09-2019, 05:32 AM
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Quick question on amp/driver math..


I plan on running 3 JBL drivers. I understand they're 4ohm drivers - and that 80 watts is their max. I've also been reading about wiring them series/parallel. It looks like I could wire 3 in series for a 12ohm load. What I don't quite understand is - if the amp I'm looking at bridges for 160 watts in a single 8 ohm channel.. I've read that when ohms double, then watts half.. SO, 12 ohm would yield 120 watts? But, that 120 watts would be used across 3 drivers - so that'd be 40 watts per driver? Does that sound like I'm understanding things correctly?


If so - I'd probably be better off buying two amps - running each channel independently at 75 watts per 4 ohm driver?
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post #3029 of 4067 Old 08-09-2019, 06:59 AM
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Originally Posted by thedudexxi View Post
Thanks for the input - that definitely helped clarify a lot of questions I had.


I did have a follow up on the first couple questions, though.


I've been reading that the stiffer the platform - the less isolators are necessary. Then - would doubling up the MDF mean I would use less isolators for optimum results?

I didn't double up mine, so went with the isos at every 2 feet apart, but I did read that others who went with a stiffer platform used less isos, so perhaps just on the corners of the board. You could try it that way first and add more if you feel like you need it.
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post #3030 of 4067 Old 08-09-2019, 09:26 AM - Thread Starter
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Thanks for the input - that definitely helped clarify a lot of questions I had.


I did have a follow up on the first couple questions, though.


I've been reading that the stiffer the platform - the less isolators are necessary. Then - would doubling up the MDF mean I would use less isolators for optimum results?
thedude....good question. As m0j0 suggested, with a rigid platform, just start with the 4 corners and if bending of the platform happens when full loaded, just add another isolator right in the middle. If bending still occurs, then add another isolator in the middle and separate those 2 isolators in the middle so they divide the platform into thirds....hope this makes sense.

Also, the platform should be constructed of plywood instead of MDF. Plywood is stiffer than MDF and won't sag over time. MDF isn't a good material for the large spans we're talking about for BOSS platforms because of the sag.

Hope this helps.
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