10” driver spec review needed, please…

[PTCary]

Hello everyone, new here working on a truck tuba from Bills plans. Coming from a low powered 8” t-line and very curious about this horn.

Deciding on 8” vs 10” but my car setup (Sony DSP) requires a dvc 2 ohm sub driver so options are limited. I read that xmax and cone area are deciders for these horns. I am working with 70 watts, currently crossed over at 70 hz, but can change the crossover point. If not satisfied then will end up looking at the Audio Control Acm 300.1 run at 4 ohms, which would be underrated at 175 watts; hoping that is not too much power for a truck tuba. Any advice is much appreciated. Love this forum and still reading/researching truck tuba.

Please take a look at specs for this B2 Audio shallow 10” and tell me what you all think? It looks close to me in specs but I do not know about qes or qts.

Fs 40 - I believe 40 is about where truck tuba is tuned to? If this matters?
Vas 20.5
Qms 3
Qes 0.62
Qts 0.514
XMax 8mm
Sd 376.5cm2

[Bill Fitzmaurice]

From the plans: Acceptable T/S specs for the driver are fs 28 to 40Hz, Qts .30 to .50, Vas 15 to 45L, xmax 8mm or more.
You don't need to spend big bucks on drivers, nor do they require high power handling. That defeats the purpose of building a horn loaded speaker. For less $$ the Dayton LS10-44 is a better driver.

[PTCary]

Thanks Bill! But the Dayton only comes in dual 4 ohm. I need a dual 2 ohm driver. I can get that B2 driver for $60.

[PTCary]

It’s a 200w rms driver and regular price is same as Dayton. If only Dayton was dual 2 ohm.

[Bruce Weldy]

Thanks Bill! But the Dayton only comes in dual 4 ohm. I need a dual 2 ohm driver. I can get that B2 driver for $60.

I'm not a car audio guy, but why is 2 ohms a requirement? 4 ohms is easier on the amp. Usually, the ohms resistance is stated as minimum - which would mean that 4 would be fine.

[PTCary]

Thanks Bill! But the Dayton only comes in dual 4 ohm. I need a dual 2 ohm driver. I can get that B2 driver for $60.

I'm not a car audio guy, but why is 2 ohms a requirement? 4 ohms is easier on the amp. Usually, the ohms resistance is stated as minimum - which would mean that 4 would be fine.

Hi Bruce. It’s an oem Ford Sony amp. It has 2 2ohm subwoofer channels. They are approx 35 watts each channel @ 2 ohms.

[Bill Fitzmaurice]

2 ohms is the minimum load, it's not the maximum load. The difference would be slight.

[PTCary]

Okay. Do you think Dayton 10 in truck tuba on 35 watts at 4 ohms would be okay in car? Is there a ‘minimum’ wattage that truck tuba needs?

[Seth]

I'm curious if those two channels are bridgeable for a single 4Ω driver. I'd imagine they are. It would certainly be worth investigating.

[PTCary]

I'm curious if those two channels are bridgeable for a single 4Ω driver. I'd imagine they are. It would certainly be worth investigating.

Thanks Seth, unsure on that. Sony Amps in Fords are not very forgiving. If so, That would open up the option of the MCM driver.

The entire system is 2 ohms. Everyone goes to an aftermarket sub amp piggybacked off of the oem stuff. I want to hear the tuba before I decide if an add on small low power amp is needed. Based on my current t-line with an Image Dynamics ID8 on 70 watts, I don’t see any reason why tuba would need more power than that, but am wondering if all other parameters are the same would there be a significant difference between 8” and 10”.

I believe the ID8 D2 fits the required specs but have to check again. If it does I may just transfer it to the tuba and go from there.

[Bill Fitzmaurice]

Pay attention to Qts. Subs intended for auto sound in sealed boxes tend to have Qts over .50, which isn't suitable for horn loading.

[PTCary]

Pay attention to Qts. Subs intended for auto sound in sealed boxes tend to have Qts over .50, which isn't suitable for horn loading.

Thanks Bill!

[PTCary]

Well I cut the hole for an 8” so no 10. I have a couple of 8”s in my collection to try out. One of them has Fs that is lower than Bills specs and the other has Vas that is lower than Bills specs. Other specs fall right in the middle of the requirements.

If they do not work well, I will end up switching my plan to 4 ohms, with ordering the small Audio Control amp and the MCM 8”.

Thanks again to everybody!

[howiez]

I'm late to this thread, but have some similar experience. Built a TT for my son's Honda Pilot. We bypassed the factory 10 and used the factory amp to power his. It was a 3ohm system. We actually chose an Infinity sub with good enough TS parameters, but also had both 2 and 4ohm wiring options with DVC. We couldn't really tell the difference and it runs fine at 4ohms. It really wakes up the low end compared to the factory system. i was (once again) blown away by Bill's designs and their efficiency. If I did it again, i'd buy the cheapest driver I could unless I had my own aftermarket amp and really wanted to pound like the kiddies.

[PTCary]

I'm late to this thread, but have some similar experience. Built a TT for my son's Honda Pilot. We bypassed the factory 10 and used the factory amp to power his. It was a 3ohm system. We actually chose an Infinity sub with good enough TS parameters, but also had both 2 and 4ohm wiring options with DVC. We couldn't really tell the difference and it runs fine at 4ohms. It really wakes up the low end compared to the factory system. i was (once again) blown away by Bill's designs and their efficiency. If I did it again, i'd buy the cheapest driver I could unless I had my own aftermarket amp and really wanted to pound like the kiddies.

Thanks for sharing your experience! I think that for anyone working with an oem amplifier, and okay with the enclosure size, these should be ideal. Just have to be aware of the impedance. I have a few different 8”s in my collection so decided to try one of them that falls in specs vs buying a new 10. I think 70 watts rms should be more than enough power for me. Really interested in the efficiency of Bills designs.