Installing 4 Inch Replacement Front Speakers

[agedbikeman]

As usual after 24 years and much wet/damp etc, my front speakers were totally shot, can't seem to find these wierd size speakers, so I used a pair of good qulity 4inch coaxial car ones with plastic cones.
Obviously they're too small, didn't fancy trying to enlarge the holes to 5inch speakers so I used 3mm perspex sub baffles or mounting plates whichever you want to call them. The sound is very good to say the least.

[Sadanorakman]

Good job sir!
For those that don't know, it's important to stop the sound waves from the rear of the speaker leaking around the edge and mingling with the sound waves generated by the front of the speaker: This tends to null out most of the bass. By having a good effective baffle in place like the perspex here, the resulting sound should be pretty good.
When it comes time for me to swap mine, I'll be trying to find some speakers that fit a bit more closely. There's always the odd larger size around like 110mm or so (approx 4.5") if you search hard enough. I'll have to see what I can find. Now if I can just find those combined with 3ohms instead of 4, and reasonably waterproof too, I'll be laughing.

[agedbikeman]

I spent ages looking for these 4 1/2 inch speakers but only found mercedes ones wothout mounting lugs.
1 ohm will make no noticable difference at all it will just cause the output devices to draw less current resulting in an un-noticable lower amplifier output.
I'd just copy me with the 4" speakers and a bit of perspex, most car speakers have plastic cones which makes the waterproof.

Alex
retired TV & audio service engineer (40years)

[Sadanorakman]

1 ohm will make no noticable difference at all it will just cause the output devices to draw less current resulting in an un-noticable lower amplifier output.
I'd just copy me with the 4" speakers and a bit of perspex, most car speakers have plastic cones which makes the waterproof.

I respectfully disagree. The OEM speakers are rated at 3ohms impedance in both the GL1500 and GL1800 for a reason. This can be assumed to be maximise the output available from the solid-state power amp in the radio.
Because these amps work only at a rail voltage equal to the bike's electrical system (somewhere between 12-14V depending upon if engine is running and battery state), the useful maximum output power delivered is entirely dependent upon the output loading impedance applied. The most you can squeeze out of this type of amplifier configuration is typically around 25 Watts RMS per channel given the limited supply voltage.
This limited supply voltage is the reason automotive speakers became lower impedance than domestic speakers many years ago.
People that have swapped OEM 3 ohm speakers for typical 4 ohm car speakers, have reported a loss of output volume. This is also down to the design of the replacement speakers being typically less efficient per watt, not just their 25% higher impedance. The OEM speakers are paper-coned, with low-loss surrounds (They are designed to be efficient). Most polypropylene-coned car speakers have higher-loss (more energy absorbing) rolled rubber or foam cone surrounds, and heavier voice-coil supporting "suspensions', all of which hurt their efficiency by stealing power. So the comparative efficiency of the new speaker at the same driven watts is already a couple of decibels down on the OEM speaker, without factoring in a 4 ohm impedance Vs 3 ohm which means the amp can only deliver a third less current (hence power) into the replacement speaker, which loses you another couple of decibels.
I've used some JBL speakers in the past (in a car), which had a larger moving cone area compared to the same 'size' of standard speaker, combined with a 3 ohm impedance. These made a surprising difference to the output power.
Of course, we could just add an external power amp that will generate a rail voltage of 50-60V internally because it uses a DC inverter. That will drive anything from 2 ohms upwards at suitable power. I would suggest however a Class D, purely for efficiency.

Regards
Craig.
HNC in electronic engineering, and 30 years electronics experience.

[Sadanorakman]

I was just looking into the JBL 3 Ohm Speakers I have used before, and unfortunately they do a 4" and a 5" one, with the 5" looking to be too large, and the 4" one being similar to the Polk's, i.e. being actually a little smaller than the OEM ones.

OEM Speaker, courtesy of another thread on this site:

A Panasonic TS-R13502S speaker, that is supposed to be a 5", but if you look at the overall width of the circular rim of the frame (111mm (approx 4 1/2"), and the distance between slotted tags (97mm (approx 3 7/8") it looks to be a very similar in size to the OEM speaker, and might just fit with some modest trimming. Ok this one doesn't look so water resistant, but for me that's not really an issue, as I'm a fair-weather rider (for pleasure only).

Does anyone have the depth of the OEM unit? are they really slim?

[agedbikeman]

Also with respect Sadanorakman, if you want to listen to hi-fi, stay at home don't expect it riding a motorbike, from your post I see you live in the UK so you must know the score, compulsory helmet, scarf, chucking it down with rain, what chance does any audio stand of anything more than average sound, but saying that, even with my speaker mod and a 24 year old radio, this wing is still a better sound than my 5 yr old spyder with state of the art radio & graphic equaliser. Each to his own.

[Sadanorakman]

Also with respect Sadanorakman, if you want to listen to hi-fi, stay at home don't expect it riding a motorbike, from your post I see you live in the UK so you must know the score, compulsory helmet, scarf, chucking it down with rain, what chance does any audio stand of anything more than average sound, but saying that, even with my speaker mod and a 24 year old radio, this wing is still a better sound than my 5 yr old spyder with state of the art radio & graphic equaliser. Each to his own.

Firstly, Helmets: I would personally never ride without one, even when abroad, where it may not be mandated. I also approve and agree with my government mandating helmet use, as it's not the rider who suffers most from a life-changing brain injury, it's usually their family. I respect other people's personal decision not to wear a helmet, even though I don't agree with them.

If the UK wasn't so wet, then it wouldn't be such a Green and Pleasant land , although I agree we are having a little too much 'wet' at the moment:

... Better this, than the wild-fires being suffered in Australia at the moment, or in California! Boy we are screwing this planet up good and proper!

Hi-Fi means different things to different people. To some it might be $100,000 dollars of bling, hewn from solid Oak and Granite, with thermionic valves popping out of the top, and gold-plated cables as thick as your index finger. For others, it might be their favourite 40 year-old turntable they bought as a teenager, and their 1960's home-made speakers, as comfortable as old slippers.

I never stated that Bike Audio has to be Hi-Fi (Whatever that means to any individual). Plenty can be done however to get adequately pleasing audio out of a modest system on a bike. Careful attention to basics like you did: ensuring an effectively sealed baffle between the front and back of a speaker, helps it to preserve at least a modicum of bass, and not be all harsh. I already congratulated you on a job well done here. A few have also had success with foam baffles like this:

My personal choice will be to chase that illusive slightly-larger speaker, that fits the dash but without major modification. I will also probably go with a Class-D amp, so I can add in some EQ and force some more Bass energy out of the modestly sized drivers. This will also make it easier to integrate Bluetooth and Aux Audio inputs.

I know of someone who fitted a 12" sub in their top-box. now that might seem ludicrous to most of us, but I guess it had the result he was seeking!

Enjoy your new Coaxial speakers agedbikeman, and above all, Ride safe: helmet or no helmet!

[jaimemu]

Hello agedbikeman, I have read your post, and I have the same problem, I cannot find valid speakers for the accommodation, I have started a similar solution (CAD design, and plastic laser cutting), fortunately before sending it to the cut, the light and I have taken a more economical and safe solution:
Cut the front speaker and leave the ring where the new speaker fits perfectly.

[jaimemu]

On the other hand, the speakers that I have bought are identical to the rear speakers of the motorcycle, so I will not have problems

[agedbikeman]

Now how come I didn't think of that, that's exactly what I did about 40 years ago with some 12inch bass speaker that were a wierd size, completely forgot I did that.
Still got the old speakers I'll give it a go next time I dismantle the dash.

Lazer cut nothing, I used offcut of perspex I had in the cellar and cut it with my electric fretsaw from Lidl.

Alex

[zeoran]

Does anyone have an updated part reference for the Kenwood speakers?

I have my bike/dash apart and figured I might as well replace the front speakers while I'm at it since the OEM's aren't sounding that awesome lately. (not that they ever did)
I know the Polk DB501's are recommended and I have the 401's in the rear but I've seen a lot of people recommend the Kenwood 1065R's for the front as having much better sound. (especially with an enclosure) but I can't find the Kenwood's anywhere in stock. Amazon is out, Best Buy is out, Crutchfield is out.

Is there a new model for the Kenwood's that would still beat the DB501's in sound quality?

God bless,

~Mark

[jaimemu]

Hi Mark, at the moment I don't have them installed, since I also change the source; an FM radio receiver and an amplifier with bluetooth, for connection from the cell phone
Until I have everything installed, I will not know the result.

Jaime